OSCL-LXR linux-6.0.1/​drivers/​gpu/​drm/​amd/​amdkfd/​kfd_svm.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0 OR MIT
 /*
  * Copyright 2020-2021 Advanced Micro Devices, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
 #include <linux/types.h>
 #include <linux/sched/task.h>
 #include "amdgpu_sync.h"
 #include "amdgpu_object.h"
 #include "amdgpu_vm.h"
 #include "amdgpu_mn.h"
 #include "amdgpu.h"
 #include "amdgpu_xgmi.h"
 #include "kfd_priv.h"
 #include "kfd_svm.h"
 #include "kfd_migrate.h"
 #include "kfd_smi_events.h"
 
 #ifdef dev_fmt
 #undef dev_fmt
 #endif
 #define dev_fmt(fmt) "kfd_svm: %s: " fmt, __func__
 
 #define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
 
 /* Long enough to ensure no retry fault comes after svm range is restored and
  * page table is updated.
  */
 #define AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING    (2UL * NSEC_PER_MSEC)
 
 /* Giant svm range split into smaller ranges based on this, it is decided using
  * minimum of all dGPU/APU 1/32 VRAM size, between 2MB to 1GB and alignment to
  * power of 2MB.
  */
 static uint64_t max_svm_range_pages;
 
 struct criu_svm_metadata {
     struct list_head list;
     struct kfd_criu_svm_range_priv_data data;
 };
 
 static void svm_range_evict_svm_bo_worker(struct work_struct *work);
 static bool
 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
                     const struct mmu_notifier_range *range,
                     unsigned long cur_seq);
 static int
 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
            uint64_t *bo_s, uint64_t *bo_l);
 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
     .invalidate = svm_range_cpu_invalidate_pagetables,
 };
 
 /**
  * svm_range_unlink - unlink svm_range from lists and interval tree
  * @prange: svm range structure to be removed
  *
  * Remove the svm_range from the svms and svm_bo lists and the svms
  * interval tree.
  *
  * Context: The caller must hold svms->lock
  */
 static void svm_range_unlink(struct svm_range *prange)
 {
     pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
          prange, prange->start, prange->last);
 
     if (prange->svm_bo) {
         spin_lock(&prange->svm_bo->list_lock);
         list_del(&prange->svm_bo_list);
         spin_unlock(&prange->svm_bo->list_lock);
     }
 
     list_del(&prange->list);
     if (prange->it_node.start != 0 && prange->it_node.last != 0)
         interval_tree_remove(&prange->it_node, &prange->svms->objects);
 }
 
 static void
 svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
 {
     pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
          prange, prange->start, prange->last);
 
     mmu_interval_notifier_insert_locked(&prange->notifier, mm,
                      prange->start << PAGE_SHIFT,
                      prange->npages << PAGE_SHIFT,
                      &svm_range_mn_ops);
 }
 
 /**
  * svm_range_add_to_svms - add svm range to svms
  * @prange: svm range structure to be added
  *
  * Add the svm range to svms interval tree and link list
  *
  * Context: The caller must hold svms->lock
  */
 static void svm_range_add_to_svms(struct svm_range *prange)
 {
     pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
          prange, prange->start, prange->last);
 
     list_move_tail(&prange->list, &prange->svms->list);
     prange->it_node.start = prange->start;
     prange->it_node.last = prange->last;
     interval_tree_insert(&prange->it_node, &prange->svms->objects);
 }
 
 static void svm_range_remove_notifier(struct svm_range *prange)
 {
     pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
          prange->svms, prange,
          prange->notifier.interval_tree.start >> PAGE_SHIFT,
          prange->notifier.interval_tree.last >> PAGE_SHIFT);
 
     if (prange->notifier.interval_tree.start != 0 &&
         prange->notifier.interval_tree.last != 0)
         mmu_interval_notifier_remove(&prange->notifier);
 }
 
 static bool
 svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
 {
     return dma_addr && !dma_mapping_error(dev, dma_addr) &&
            !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
 }
 
 static int
 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
               unsigned long offset, unsigned long npages,
               unsigned long *hmm_pfns, uint32_t gpuidx)
 {
     enum dma_data_direction dir = DMA_BIDIRECTIONAL;
     dma_addr_t *addr = prange->dma_addr[gpuidx];
     struct device *dev = adev->dev;
     struct page *page;
     int i, r;
 
     if (!addr) {
         addr = kvcalloc(prange->npages, sizeof(*addr), GFP_KERNEL);
         if (!addr)
             return -ENOMEM;
         prange->dma_addr[gpuidx] = addr;
     }
 
     addr += offset;
     for (i = 0; i < npages; i++) {
         if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
             dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
 
         page = hmm_pfn_to_page(hmm_pfns[i]);
         if (is_zone_device_page(page)) {
             struct amdgpu_device *bo_adev =
                     amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
 
             addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
                    bo_adev->vm_manager.vram_base_offset -
                    bo_adev->kfd.dev->pgmap.range.start;
             addr[i] |= SVM_RANGE_VRAM_DOMAIN;
             pr_debug_ratelimited("vram address: 0x%llx\n", addr[i]);
             continue;
         }
         addr[i] = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
         r = dma_mapping_error(dev, addr[i]);
         if (r) {
             dev_err(dev, "failed %d dma_map_page\n", r);
             return r;
         }
         pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
                      addr[i] >> PAGE_SHIFT, page_to_pfn(page));
     }
     return 0;
 }
 
 static int
 svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
           unsigned long offset, unsigned long npages,
           unsigned long *hmm_pfns)
 {
     struct kfd_process *p;
     uint32_t gpuidx;
     int r;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
         struct kfd_process_device *pdd;
 
         pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
         pdd = kfd_process_device_from_gpuidx(p, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             return -EINVAL;
         }
 
         r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
                       hmm_pfns, gpuidx);
         if (r)
             break;
     }
 
     return r;
 }
 
 void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
              unsigned long offset, unsigned long npages)
 {
     enum dma_data_direction dir = DMA_BIDIRECTIONAL;
     int i;
 
     if (!dma_addr)
         return;
 
     for (i = offset; i < offset + npages; i++) {
         if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
             continue;
         pr_debug_ratelimited("unmap 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
         dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
         dma_addr[i] = 0;
     }
 }
 
 void svm_range_free_dma_mappings(struct svm_range *prange)
 {
     struct kfd_process_device *pdd;
     dma_addr_t *dma_addr;
     struct device *dev;
     struct kfd_process *p;
     uint32_t gpuidx;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
         dma_addr = prange->dma_addr[gpuidx];
         if (!dma_addr)
             continue;
 
         pdd = kfd_process_device_from_gpuidx(p, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             continue;
         }
         dev = &pdd->dev->pdev->dev;
         svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
         kvfree(dma_addr);
         prange->dma_addr[gpuidx] = NULL;
     }
 }
 
 static void svm_range_free(struct svm_range *prange, bool update_mem_usage)
 {
     uint64_t size = (prange->last - prange->start + 1) << PAGE_SHIFT;
     struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
 
     pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
          prange->start, prange->last);
 
     svm_range_vram_node_free(prange);
     svm_range_free_dma_mappings(prange);
 
     if (update_mem_usage && !p->xnack_enabled) {
         pr_debug("unreserve mem limit: %lld\n", size);
         amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
                     KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
     }
     mutex_destroy(&prange->lock);
     mutex_destroy(&prange->migrate_mutex);
     kfree(prange);
 }
 
 static void
 svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,
                  uint8_t *granularity, uint32_t *flags)
 {
     *location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
     *prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
     *granularity = 9;
     *flags =
         KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;
 }
 
 static struct
 svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
              uint64_t last, bool update_mem_usage)
 {
     uint64_t size = last - start + 1;
     struct svm_range *prange;
     struct kfd_process *p;
 
     prange = kzalloc(sizeof(*prange), GFP_KERNEL);
     if (!prange)
         return NULL;
 
     p = container_of(svms, struct kfd_process, svms);
     if (!p->xnack_enabled && update_mem_usage &&
         amdgpu_amdkfd_reserve_mem_limit(NULL, size << PAGE_SHIFT,
                         KFD_IOC_ALLOC_MEM_FLAGS_USERPTR)) {
         pr_info("SVM mapping failed, exceeds resident system memory limit\n");
         kfree(prange);
         return NULL;
     }
     prange->npages = size;
     prange->svms = svms;
     prange->start = start;
     prange->last = last;
     INIT_LIST_HEAD(&prange->list);
     INIT_LIST_HEAD(&prange->update_list);
     INIT_LIST_HEAD(&prange->svm_bo_list);
     INIT_LIST_HEAD(&prange->deferred_list);
     INIT_LIST_HEAD(&prange->child_list);
     atomic_set(&prange->invalid, 0);
     prange->validate_timestamp = 0;
     mutex_init(&prange->migrate_mutex);
     mutex_init(&prange->lock);
 
     if (p->xnack_enabled)
         bitmap_copy(prange->bitmap_access, svms->bitmap_supported,
                 MAX_GPU_INSTANCE);
 
     svm_range_set_default_attributes(&prange->preferred_loc,
                      &prange->prefetch_loc,
                      &prange->granularity, &prange->flags);
 
     pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last);
 
     return prange;
 }
 
 static bool svm_bo_ref_unless_zero(struct svm_range_bo *svm_bo)
 {
     if (!svm_bo || !kref_get_unless_zero(&svm_bo->kref))
         return false;
 
     return true;
 }
 
 static void svm_range_bo_release(struct kref *kref)
 {
     struct svm_range_bo *svm_bo;
 
     svm_bo = container_of(kref, struct svm_range_bo, kref);
     pr_debug("svm_bo 0x%p\n", svm_bo);
 
     spin_lock(&svm_bo->list_lock);
     while (!list_empty(&svm_bo->range_list)) {
         struct svm_range *prange =
                 list_first_entry(&svm_bo->range_list,
                         struct svm_range, svm_bo_list);
         /* list_del_init tells a concurrent svm_range_vram_node_new when
          * it's safe to reuse the svm_bo pointer and svm_bo_list head.
          */
         list_del_init(&prange->svm_bo_list);
         spin_unlock(&svm_bo->list_lock);
 
         pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
              prange->start, prange->last);
         mutex_lock(&prange->lock);
         prange->svm_bo = NULL;
         mutex_unlock(&prange->lock);
 
         spin_lock(&svm_bo->list_lock);
     }
     spin_unlock(&svm_bo->list_lock);
     if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
         /* We're not in the eviction worker.
          * Signal the fence and synchronize with any
          * pending eviction work.
          */
         dma_fence_signal(&svm_bo->eviction_fence->base);
         cancel_work_sync(&svm_bo->eviction_work);
     }
     dma_fence_put(&svm_bo->eviction_fence->base);
     amdgpu_bo_unref(&svm_bo->bo);
     kfree(svm_bo);
 }
 
 static void svm_range_bo_wq_release(struct work_struct *work)
 {
     struct svm_range_bo *svm_bo;
 
     svm_bo = container_of(work, struct svm_range_bo, release_work);
     svm_range_bo_release(&svm_bo->kref);
 }
 
 static void svm_range_bo_release_async(struct kref *kref)
 {
     struct svm_range_bo *svm_bo;
 
     svm_bo = container_of(kref, struct svm_range_bo, kref);
     pr_debug("svm_bo 0x%p\n", svm_bo);
     INIT_WORK(&svm_bo->release_work, svm_range_bo_wq_release);
     schedule_work(&svm_bo->release_work);
 }
 
 void svm_range_bo_unref_async(struct svm_range_bo *svm_bo)
 {
     kref_put(&svm_bo->kref, svm_range_bo_release_async);
 }
 
 static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
 {
     if (svm_bo)
         kref_put(&svm_bo->kref, svm_range_bo_release);
 }
 
 static bool
 svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
 {
     struct amdgpu_device *bo_adev;
 
     mutex_lock(&prange->lock);
     if (!prange->svm_bo) {
         mutex_unlock(&prange->lock);
         return false;
     }
     if (prange->ttm_res) {
         /* We still have a reference, all is well */
         mutex_unlock(&prange->lock);
         return true;
     }
     if (svm_bo_ref_unless_zero(prange->svm_bo)) {
         /*
          * Migrate from GPU to GPU, remove range from source bo_adev
          * svm_bo range list, and return false to allocate svm_bo from
          * destination adev.
          */
         bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
         if (bo_adev != adev) {
             mutex_unlock(&prange->lock);
 
             spin_lock(&prange->svm_bo->list_lock);
             list_del_init(&prange->svm_bo_list);
             spin_unlock(&prange->svm_bo->list_lock);
 
             svm_range_bo_unref(prange->svm_bo);
             return false;
         }
         if (READ_ONCE(prange->svm_bo->evicting)) {
             struct dma_fence *f;
             struct svm_range_bo *svm_bo;
             /* The BO is getting evicted,
              * we need to get a new one
              */
             mutex_unlock(&prange->lock);
             svm_bo = prange->svm_bo;
             f = dma_fence_get(&svm_bo->eviction_fence->base);
             svm_range_bo_unref(prange->svm_bo);
             /* wait for the fence to avoid long spin-loop
              * at list_empty_careful
              */
             dma_fence_wait(f, false);
             dma_fence_put(f);
         } else {
             /* The BO was still around and we got
              * a new reference to it
              */
             mutex_unlock(&prange->lock);
             pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
                  prange->svms, prange->start, prange->last);
 
             prange->ttm_res = prange->svm_bo->bo->tbo.resource;
             return true;
         }
 
     } else {
         mutex_unlock(&prange->lock);
     }
 
     /* We need a new svm_bo. Spin-loop to wait for concurrent
      * svm_range_bo_release to finish removing this range from
      * its range list. After this, it is safe to reuse the
      * svm_bo pointer and svm_bo_list head.
      */
     while (!list_empty_careful(&prange->svm_bo_list))
         ;
 
     return false;
 }
 
 static struct svm_range_bo *svm_range_bo_new(void)
 {
     struct svm_range_bo *svm_bo;
 
     svm_bo = kzalloc(sizeof(*svm_bo), GFP_KERNEL);
     if (!svm_bo)
         return NULL;
 
     kref_init(&svm_bo->kref);
     INIT_LIST_HEAD(&svm_bo->range_list);
     spin_lock_init(&svm_bo->list_lock);
 
     return svm_bo;
 }
 
 int
 svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
             bool clear)
 {
     struct amdgpu_bo_param bp;
     struct svm_range_bo *svm_bo;
     struct amdgpu_bo_user *ubo;
     struct amdgpu_bo *bo;
     struct kfd_process *p;
     struct mm_struct *mm;
     int r;
 
     p = container_of(prange->svms, struct kfd_process, svms);
     pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
          prange->start, prange->last);
 
     if (svm_range_validate_svm_bo(adev, prange))
         return 0;
 
     svm_bo = svm_range_bo_new();
     if (!svm_bo) {
         pr_debug("failed to alloc svm bo\n");
         return -ENOMEM;
     }
     mm = get_task_mm(p->lead_thread);
     if (!mm) {
         pr_debug("failed to get mm\n");
         kfree(svm_bo);
         return -ESRCH;
     }
     svm_bo->eviction_fence =
         amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
                        mm,
                        svm_bo);
     mmput(mm);
     INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
     svm_bo->evicting = 0;
     memset(&bp, 0, sizeof(bp));
     bp.size = prange->npages * PAGE_SIZE;
     bp.byte_align = PAGE_SIZE;
     bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
     bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
     bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
     bp.flags |= AMDGPU_GEM_CREATE_DISCARDABLE;
     bp.type = ttm_bo_type_device;
     bp.resv = NULL;
 
     r = amdgpu_bo_create_user(adev, &bp, &ubo);
     if (r) {
         pr_debug("failed %d to create bo\n", r);
         goto create_bo_failed;
     }
     bo = &ubo->bo;
     r = amdgpu_bo_reserve(bo, true);
     if (r) {
         pr_debug("failed %d to reserve bo\n", r);
         goto reserve_bo_failed;
     }
 
     r = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
     if (r) {
         pr_debug("failed %d to reserve bo\n", r);
         amdgpu_bo_unreserve(bo);
         goto reserve_bo_failed;
     }
     amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
 
     amdgpu_bo_unreserve(bo);
 
     svm_bo->bo = bo;
     prange->svm_bo = svm_bo;
     prange->ttm_res = bo->tbo.resource;
     prange->offset = 0;
 
     spin_lock(&svm_bo->list_lock);
     list_add(&prange->svm_bo_list, &svm_bo->range_list);
     spin_unlock(&svm_bo->list_lock);
 
     return 0;
 
 reserve_bo_failed:
     amdgpu_bo_unref(&bo);
 create_bo_failed:
     dma_fence_put(&svm_bo->eviction_fence->base);
     kfree(svm_bo);
     prange->ttm_res = NULL;
 
     return r;
 }
 
 void svm_range_vram_node_free(struct svm_range *prange)
 {
     svm_range_bo_unref(prange->svm_bo);
     prange->ttm_res = NULL;
 }
 
 struct amdgpu_device *
 svm_range_get_adev_by_id(struct svm_range *prange, uint32_t gpu_id)
 {
     struct kfd_process_device *pdd;
     struct kfd_process *p;
     int32_t gpu_idx;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     gpu_idx = kfd_process_gpuidx_from_gpuid(p, gpu_id);
     if (gpu_idx < 0) {
         pr_debug("failed to get device by id 0x%x\n", gpu_id);
         return NULL;
     }
     pdd = kfd_process_device_from_gpuidx(p, gpu_idx);
     if (!pdd) {
         pr_debug("failed to get device by idx 0x%x\n", gpu_idx);
         return NULL;
     }
 
     return pdd->dev->adev;
 }
 
 struct kfd_process_device *
 svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev)
 {
     struct kfd_process *p;
     int32_t gpu_idx, gpuid;
     int r;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpu_idx);
     if (r) {
         pr_debug("failed to get device id by adev %p\n", adev);
         return NULL;
     }
 
     return kfd_process_device_from_gpuidx(p, gpu_idx);
 }
 
 static int svm_range_bo_validate(void *param, struct amdgpu_bo *bo)
 {
     struct ttm_operation_ctx ctx = { false, false };
 
     amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_VRAM);
 
     return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
 }
 
 static int
 svm_range_check_attr(struct kfd_process *p,
              uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
 {
     uint32_t i;
 
     for (i = 0; i < nattr; i++) {
         uint32_t val = attrs[i].value;
         int gpuidx = MAX_GPU_INSTANCE;
 
         switch (attrs[i].type) {
         case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
             if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM &&
                 val != KFD_IOCTL_SVM_LOCATION_UNDEFINED)
                 gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
             break;
         case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
             if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM)
                 gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
             break;
         case KFD_IOCTL_SVM_ATTR_ACCESS:
         case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
         case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
             gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
             break;
         case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
             break;
         case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
             break;
         case KFD_IOCTL_SVM_ATTR_GRANULARITY:
             break;
         default:
             pr_debug("unknown attr type 0x%x\n", attrs[i].type);
             return -EINVAL;
         }
 
         if (gpuidx < 0) {
             pr_debug("no GPU 0x%x found\n", val);
             return -EINVAL;
         } else if (gpuidx < MAX_GPU_INSTANCE &&
                !test_bit(gpuidx, p->svms.bitmap_supported)) {
             pr_debug("GPU 0x%x not supported\n", val);
             return -EINVAL;
         }
     }
 
     return 0;
 }
 
 static void
 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
               uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
               bool *update_mapping)
 {
     uint32_t i;
     int gpuidx;
 
     for (i = 0; i < nattr; i++) {
         switch (attrs[i].type) {
         case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
             prange->preferred_loc = attrs[i].value;
             break;
         case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
             prange->prefetch_loc = attrs[i].value;
             break;
         case KFD_IOCTL_SVM_ATTR_ACCESS:
         case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
         case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
             *update_mapping = true;
             gpuidx = kfd_process_gpuidx_from_gpuid(p,
                                    attrs[i].value);
             if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
                 bitmap_clear(prange->bitmap_access, gpuidx, 1);
                 bitmap_clear(prange->bitmap_aip, gpuidx, 1);
             } else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
                 bitmap_set(prange->bitmap_access, gpuidx, 1);
                 bitmap_clear(prange->bitmap_aip, gpuidx, 1);
             } else {
                 bitmap_clear(prange->bitmap_access, gpuidx, 1);
                 bitmap_set(prange->bitmap_aip, gpuidx, 1);
             }
             break;
         case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
             *update_mapping = true;
             prange->flags |= attrs[i].value;
             break;
         case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
             *update_mapping = true;
             prange->flags &= ~attrs[i].value;
             break;
         case KFD_IOCTL_SVM_ATTR_GRANULARITY:
             prange->granularity = attrs[i].value;
             break;
         default:
             WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
         }
     }
 }
 
 static bool
 svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
             uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
 {
     uint32_t i;
     int gpuidx;
 
     for (i = 0; i < nattr; i++) {
         switch (attrs[i].type) {
         case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
             if (prange->preferred_loc != attrs[i].value)
                 return false;
             break;
         case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
             /* Prefetch should always trigger a migration even
              * if the value of the attribute didn't change.
              */
             return false;
         case KFD_IOCTL_SVM_ATTR_ACCESS:
         case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
         case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
             gpuidx = kfd_process_gpuidx_from_gpuid(p,
                                    attrs[i].value);
             if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
                 if (test_bit(gpuidx, prange->bitmap_access) ||
                     test_bit(gpuidx, prange->bitmap_aip))
                     return false;
             } else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
                 if (!test_bit(gpuidx, prange->bitmap_access))
                     return false;
             } else {
                 if (!test_bit(gpuidx, prange->bitmap_aip))
                     return false;
             }
             break;
         case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
             if ((prange->flags & attrs[i].value) != attrs[i].value)
                 return false;
             break;
         case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
             if ((prange->flags & attrs[i].value) != 0)
                 return false;
             break;
         case KFD_IOCTL_SVM_ATTR_GRANULARITY:
             if (prange->granularity != attrs[i].value)
                 return false;
             break;
         default:
             WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
         }
     }
 
     return true;
 }
 
 /**
  * svm_range_debug_dump - print all range information from svms
  * @svms: svm range list header
  *
  * debug output svm range start, end, prefetch location from svms
  * interval tree and link list
  *
  * Context: The caller must hold svms->lock
  */
 static void svm_range_debug_dump(struct svm_range_list *svms)
 {
     struct interval_tree_node *node;
     struct svm_range *prange;
 
     pr_debug("dump svms 0x%p list\n", svms);
     pr_debug("range\tstart\tpage\tend\t\tlocation\n");
 
     list_for_each_entry(prange, &svms->list, list) {
         pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
              prange, prange->start, prange->npages,
              prange->start + prange->npages - 1,
              prange->actual_loc);
     }
 
     pr_debug("dump svms 0x%p interval tree\n", svms);
     pr_debug("range\tstart\tpage\tend\t\tlocation\n");
     node = interval_tree_iter_first(&svms->objects, 0, ~0ULL);
     while (node) {
         prange = container_of(node, struct svm_range, it_node);
         pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
              prange, prange->start, prange->npages,
              prange->start + prange->npages - 1,
              prange->actual_loc);
         node = interval_tree_iter_next(node, 0, ~0ULL);
     }
 }
 
 static int
 svm_range_split_array(void *ppnew, void *ppold, size_t size,
               uint64_t old_start, uint64_t old_n,
               uint64_t new_start, uint64_t new_n)
 {
     unsigned char *new, *old, *pold;
     uint64_t d;
 
     if (!ppold)
         return 0;
     pold = *(unsigned char **)ppold;
     if (!pold)
         return 0;
 
     new = kvmalloc_array(new_n, size, GFP_KERNEL);
     if (!new)
         return -ENOMEM;
 
     d = (new_start - old_start) * size;
     memcpy(new, pold + d, new_n * size);
 
     old = kvmalloc_array(old_n, size, GFP_KERNEL);
     if (!old) {
         kvfree(new);
         return -ENOMEM;
     }
 
     d = (new_start == old_start) ? new_n * size : 0;
     memcpy(old, pold + d, old_n * size);
 
     kvfree(pold);
     *(void **)ppold = old;
     *(void **)ppnew = new;
 
     return 0;
 }
 
 static int
 svm_range_split_pages(struct svm_range *new, struct svm_range *old,
               uint64_t start, uint64_t last)
 {
     uint64_t npages = last - start + 1;
     int i, r;
 
     for (i = 0; i < MAX_GPU_INSTANCE; i++) {
         r = svm_range_split_array(&new->dma_addr[i], &old->dma_addr[i],
                       sizeof(*old->dma_addr[i]), old->start,
                       npages, new->start, new->npages);
         if (r)
             return r;
     }
 
     return 0;
 }
 
 static int
 svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
               uint64_t start, uint64_t last)
 {
     uint64_t npages = last - start + 1;
 
     pr_debug("svms 0x%p new prange 0x%p start 0x%lx [0x%llx 0x%llx]\n",
          new->svms, new, new->start, start, last);
 
     if (new->start == old->start) {
         new->offset = old->offset;
         old->offset += new->npages;
     } else {
         new->offset = old->offset + npages;
     }
 
     new->svm_bo = svm_range_bo_ref(old->svm_bo);
     new->ttm_res = old->ttm_res;
 
     spin_lock(&new->svm_bo->list_lock);
     list_add(&new->svm_bo_list, &new->svm_bo->range_list);
     spin_unlock(&new->svm_bo->list_lock);
 
     return 0;
 }
 
 /**
  * svm_range_split_adjust - split range and adjust
  *
  * @new: new range
  * @old: the old range
  * @start: the old range adjust to start address in pages
  * @last: the old range adjust to last address in pages
  *
  * Copy system memory dma_addr or vram ttm_res in old range to new
  * range from new_start up to size new->npages, the remaining old range is from
  * start to last
  *
  * Return:
  * 0 - OK, -ENOMEM - out of memory
  */
 static int
 svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
               uint64_t start, uint64_t last)
 {
     int r;
 
     pr_debug("svms 0x%p new 0x%lx old [0x%lx 0x%lx] => [0x%llx 0x%llx]\n",
          new->svms, new->start, old->start, old->last, start, last);
 
     if (new->start < old->start ||
         new->last > old->last) {
         WARN_ONCE(1, "invalid new range start or last\n");
         return -EINVAL;
     }
 
     r = svm_range_split_pages(new, old, start, last);
     if (r)
         return r;
 
     if (old->actual_loc && old->ttm_res) {
         r = svm_range_split_nodes(new, old, start, last);
         if (r)
             return r;
     }
 
     old->npages = last - start + 1;
     old->start = start;
     old->last = last;
     new->flags = old->flags;
     new->preferred_loc = old->preferred_loc;
     new->prefetch_loc = old->prefetch_loc;
     new->actual_loc = old->actual_loc;
     new->granularity = old->granularity;
     new->mapped_to_gpu = old->mapped_to_gpu;
     bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
     bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
 
     return 0;
 }
 
 /**
  * svm_range_split - split a range in 2 ranges
  *
  * @prange: the svm range to split
  * @start: the remaining range start address in pages
  * @last: the remaining range last address in pages
  * @new: the result new range generated
  *
  * Two cases only:
  * case 1: if start == prange->start
  *         prange ==> prange[start, last]
  *         new range [last + 1, prange->last]
  *
  * case 2: if last == prange->last
  *         prange ==> prange[start, last]
  *         new range [prange->start, start - 1]
  *
  * Return:
  * 0 - OK, -ENOMEM - out of memory, -EINVAL - invalid start, last
  */
 static int
 svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
         struct svm_range **new)
 {
     uint64_t old_start = prange->start;
     uint64_t old_last = prange->last;
     struct svm_range_list *svms;
     int r = 0;
 
     pr_debug("svms 0x%p [0x%llx 0x%llx] to [0x%llx 0x%llx]\n", prange->svms,
          old_start, old_last, start, last);
 
     if (old_start != start && old_last != last)
         return -EINVAL;
     if (start < old_start || last > old_last)
         return -EINVAL;
 
     svms = prange->svms;
     if (old_start == start)
         *new = svm_range_new(svms, last + 1, old_last, false);
     else
         *new = svm_range_new(svms, old_start, start - 1, false);
     if (!*new)
         return -ENOMEM;
 
     r = svm_range_split_adjust(*new, prange, start, last);
     if (r) {
         pr_debug("failed %d split [0x%llx 0x%llx] to [0x%llx 0x%llx]\n",
              r, old_start, old_last, start, last);
         svm_range_free(*new, false);
         *new = NULL;
     }
 
     return r;
 }
 
 static int
 svm_range_split_tail(struct svm_range *prange,
              uint64_t new_last, struct list_head *insert_list)
 {
     struct svm_range *tail;
     int r = svm_range_split(prange, prange->start, new_last, &tail);
 
     if (!r)
         list_add(&tail->list, insert_list);
     return r;
 }
 
 static int
 svm_range_split_head(struct svm_range *prange,
              uint64_t new_start, struct list_head *insert_list)
 {
     struct svm_range *head;
     int r = svm_range_split(prange, new_start, prange->last, &head);
 
     if (!r)
         list_add(&head->list, insert_list);
     return r;
 }
 
 static void
 svm_range_add_child(struct svm_range *prange, struct mm_struct *mm,
             struct svm_range *pchild, enum svm_work_list_ops op)
 {
     pr_debug("add child 0x%p [0x%lx 0x%lx] to prange 0x%p child list %d\n",
          pchild, pchild->start, pchild->last, prange, op);
 
     pchild->work_item.mm = mm;
     pchild->work_item.op = op;
     list_add_tail(&pchild->child_list, &prange->child_list);
 }
 
 /**
  * svm_range_split_by_granularity - collect ranges within granularity boundary
  *
  * @p: the process with svms list
  * @mm: mm structure
  * @addr: the vm fault address in pages, to split the prange
  * @parent: parent range if prange is from child list
  * @prange: prange to split
  *
  * Trims @prange to be a single aligned block of prange->granularity if
  * possible. The head and tail are added to the child_list in @parent.
  *
  * Context: caller must hold mmap_read_lock and prange->lock
  *
  * Return:
  * 0 - OK, otherwise error code
  */
 int
 svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
                    unsigned long addr, struct svm_range *parent,
                    struct svm_range *prange)
 {
     struct svm_range *head, *tail;
     unsigned long start, last, size;
     int r;
 
     /* Align splited range start and size to granularity size, then a single
      * PTE will be used for whole range, this reduces the number of PTE
      * updated and the L1 TLB space used for translation.
      */
     size = 1UL << prange->granularity;
     start = ALIGN_DOWN(addr, size);
     last = ALIGN(addr + 1, size) - 1;
 
     pr_debug("svms 0x%p split [0x%lx 0x%lx] to [0x%lx 0x%lx] size 0x%lx\n",
          prange->svms, prange->start, prange->last, start, last, size);
 
     if (start > prange->start) {
         r = svm_range_split(prange, start, prange->last, &head);
         if (r)
             return r;
         svm_range_add_child(parent, mm, head, SVM_OP_ADD_RANGE);
     }
 
     if (last < prange->last) {
         r = svm_range_split(prange, prange->start, last, &tail);
         if (r)
             return r;
         svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
     }
 
     /* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
     if (p->xnack_enabled && prange->work_item.op == SVM_OP_ADD_RANGE) {
         prange->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
         pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
              prange, prange->start, prange->last,
              SVM_OP_ADD_RANGE_AND_MAP);
     }
     return 0;
 }
 
 static uint64_t
 svm_range_get_pte_flags(struct amdgpu_device *adev, struct svm_range *prange,
             int domain)
 {
     struct amdgpu_device *bo_adev;
     uint32_t flags = prange->flags;
     uint32_t mapping_flags = 0;
     uint64_t pte_flags;
     bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
     bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
 
     if (domain == SVM_RANGE_VRAM_DOMAIN)
         bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
 
     switch (KFD_GC_VERSION(adev->kfd.dev)) {
     case IP_VERSION(9, 4, 1):
         if (domain == SVM_RANGE_VRAM_DOMAIN) {
             if (bo_adev == adev) {
                 mapping_flags |= coherent ?
                     AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
             } else {
                 mapping_flags |= coherent ?
                     AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
                 if (amdgpu_xgmi_same_hive(adev, bo_adev))
                     snoop = true;
             }
         } else {
             mapping_flags |= coherent ?
                 AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
         }
         break;
     case IP_VERSION(9, 4, 2):
         if (domain == SVM_RANGE_VRAM_DOMAIN) {
             if (bo_adev == adev) {
                 mapping_flags |= coherent ?
                     AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
                 if (adev->gmc.xgmi.connected_to_cpu)
                     snoop = true;
             } else {
                 mapping_flags |= coherent ?
                     AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
                 if (amdgpu_xgmi_same_hive(adev, bo_adev))
                     snoop = true;
             }
         } else {
             mapping_flags |= coherent ?
                 AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
         }
         break;
     default:
         mapping_flags |= coherent ?
             AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
     }
 
     mapping_flags |= AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE;
 
     if (flags & KFD_IOCTL_SVM_FLAG_GPU_RO)
         mapping_flags &= ~AMDGPU_VM_PAGE_WRITEABLE;
     if (flags & KFD_IOCTL_SVM_FLAG_GPU_EXEC)
         mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;
 
     pte_flags = AMDGPU_PTE_VALID;
     pte_flags |= (domain == SVM_RANGE_VRAM_DOMAIN) ? 0 : AMDGPU_PTE_SYSTEM;
     pte_flags |= snoop ? AMDGPU_PTE_SNOOPED : 0;
 
     pte_flags |= amdgpu_gem_va_map_flags(adev, mapping_flags);
     return pte_flags;
 }
 
 static int
 svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
              uint64_t start, uint64_t last,
              struct dma_fence **fence)
 {
     uint64_t init_pte_value = 0;
 
     pr_debug("[0x%llx 0x%llx]\n", start, last);
 
     return amdgpu_vm_update_range(adev, vm, false, true, true, NULL, start,
                       last, init_pte_value, 0, 0, NULL, NULL,
                       fence);
 }
 
 static int
 svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
               unsigned long last, uint32_t trigger)
 {
     DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
     struct kfd_process_device *pdd;
     struct dma_fence *fence = NULL;
     struct kfd_process *p;
     uint32_t gpuidx;
     int r = 0;
 
     if (!prange->mapped_to_gpu) {
         pr_debug("prange 0x%p [0x%lx 0x%lx] not mapped to GPU\n",
              prange, prange->start, prange->last);
         return 0;
     }
 
     if (prange->start == start && prange->last == last) {
         pr_debug("unmap svms 0x%p prange 0x%p\n", prange->svms, prange);
         prange->mapped_to_gpu = false;
     }
 
     bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
           MAX_GPU_INSTANCE);
     p = container_of(prange->svms, struct kfd_process, svms);
 
     for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
         pr_debug("unmap from gpu idx 0x%x\n", gpuidx);
         pdd = kfd_process_device_from_gpuidx(p, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             return -EINVAL;
         }
 
         kfd_smi_event_unmap_from_gpu(pdd->dev, p->lead_thread->pid,
                          start, last, trigger);
 
         r = svm_range_unmap_from_gpu(pdd->dev->adev,
                          drm_priv_to_vm(pdd->drm_priv),
                          start, last, &fence);
         if (r)
             break;
 
         if (fence) {
             r = dma_fence_wait(fence, false);
             dma_fence_put(fence);
             fence = NULL;
             if (r)
                 break;
         }
         kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
     }
 
     return r;
 }
 
 static int
 svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
              unsigned long offset, unsigned long npages, bool readonly,
              dma_addr_t *dma_addr, struct amdgpu_device *bo_adev,
              struct dma_fence **fence, bool flush_tlb)
 {
     struct amdgpu_device *adev = pdd->dev->adev;
     struct amdgpu_vm *vm = drm_priv_to_vm(pdd->drm_priv);
     uint64_t pte_flags;
     unsigned long last_start;
     int last_domain;
     int r = 0;
     int64_t i, j;
 
     last_start = prange->start + offset;
 
     pr_debug("svms 0x%p [0x%lx 0x%lx] readonly %d\n", prange->svms,
          last_start, last_start + npages - 1, readonly);
 
     for (i = offset; i < offset + npages; i++) {
         last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
         dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
 
         /* Collect all pages in the same address range and memory domain
          * that can be mapped with a single call to update mapping.
          */
         if (i < offset + npages - 1 &&
             last_domain == (dma_addr[i + 1] & SVM_RANGE_VRAM_DOMAIN))
             continue;
 
         pr_debug("Mapping range [0x%lx 0x%llx] on domain: %s\n",
              last_start, prange->start + i, last_domain ? "GPU" : "CPU");
 
         pte_flags = svm_range_get_pte_flags(adev, prange, last_domain);
         if (readonly)
             pte_flags &= ~AMDGPU_PTE_WRITEABLE;
 
         pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n",
              prange->svms, last_start, prange->start + i,
              (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
              pte_flags);
 
         r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, NULL,
                        last_start, prange->start + i,
                        pte_flags,
                        (last_start - prange->start) << PAGE_SHIFT,
                        bo_adev ? bo_adev->vm_manager.vram_base_offset : 0,
                        NULL, dma_addr, &vm->last_update);
 
         for (j = last_start - prange->start; j <= i; j++)
             dma_addr[j] |= last_domain;
 
         if (r) {
             pr_debug("failed %d to map to gpu 0x%lx\n", r, prange->start);
             goto out;
         }
         last_start = prange->start + i + 1;
     }
 
     r = amdgpu_vm_update_pdes(adev, vm, false);
     if (r) {
         pr_debug("failed %d to update directories 0x%lx\n", r,
              prange->start);
         goto out;
     }
 
     if (fence)
         *fence = dma_fence_get(vm->last_update);
 
 out:
     return r;
 }
 
 static int
 svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
               unsigned long npages, bool readonly,
               unsigned long *bitmap, bool wait, bool flush_tlb)
 {
     struct kfd_process_device *pdd;
     struct amdgpu_device *bo_adev;
     struct kfd_process *p;
     struct dma_fence *fence = NULL;
     uint32_t gpuidx;
     int r = 0;
 
     if (prange->svm_bo && prange->ttm_res)
         bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
     else
         bo_adev = NULL;
 
     p = container_of(prange->svms, struct kfd_process, svms);
     for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
         pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
         pdd = kfd_process_device_from_gpuidx(p, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             return -EINVAL;
         }
 
         pdd = kfd_bind_process_to_device(pdd->dev, p);
         if (IS_ERR(pdd))
             return -EINVAL;
 
         if (bo_adev && pdd->dev->adev != bo_adev &&
             !amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
             pr_debug("cannot map to device idx %d\n", gpuidx);
             continue;
         }
 
         r = svm_range_map_to_gpu(pdd, prange, offset, npages, readonly,
                      prange->dma_addr[gpuidx],
                      bo_adev, wait ? &fence : NULL,
                      flush_tlb);
         if (r)
             break;
 
         if (fence) {
             r = dma_fence_wait(fence, false);
             dma_fence_put(fence);
             fence = NULL;
             if (r) {
                 pr_debug("failed %d to dma fence wait\n", r);
                 break;
             }
         }
 
         kfd_flush_tlb(pdd, TLB_FLUSH_LEGACY);
     }
 
     return r;
 }
 
 struct svm_validate_context {
     struct kfd_process *process;
     struct svm_range *prange;
     bool intr;
     DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
     struct ttm_validate_buffer tv[MAX_GPU_INSTANCE];
     struct list_head validate_list;
     struct ww_acquire_ctx ticket;
 };
 
 static int svm_range_reserve_bos(struct svm_validate_context *ctx)
 {
     struct kfd_process_device *pdd;
     struct amdgpu_vm *vm;
     uint32_t gpuidx;
     int r;
 
     INIT_LIST_HEAD(&ctx->validate_list);
     for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
         pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             return -EINVAL;
         }
         vm = drm_priv_to_vm(pdd->drm_priv);
 
         ctx->tv[gpuidx].bo = &vm->root.bo->tbo;
         ctx->tv[gpuidx].num_shared = 4;
         list_add(&ctx->tv[gpuidx].head, &ctx->validate_list);
     }
 
     r = ttm_eu_reserve_buffers(&ctx->ticket, &ctx->validate_list,
                    ctx->intr, NULL);
     if (r) {
         pr_debug("failed %d to reserve bo\n", r);
         return r;
     }
 
     for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
         pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
         if (!pdd) {
             pr_debug("failed to find device idx %d\n", gpuidx);
             r = -EINVAL;
             goto unreserve_out;
         }
 
         r = amdgpu_vm_validate_pt_bos(pdd->dev->adev,
                           drm_priv_to_vm(pdd->drm_priv),
                           svm_range_bo_validate, NULL);
         if (r) {
             pr_debug("failed %d validate pt bos\n", r);
             goto unreserve_out;
         }
     }
 
     return 0;
 
 unreserve_out:
     ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
     return r;
 }
 
 static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
 {
     ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
 }
 
 static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
 {
     struct kfd_process_device *pdd;
 
     pdd = kfd_process_device_from_gpuidx(p, gpuidx);
 
     return SVM_ADEV_PGMAP_OWNER(pdd->dev->adev);
 }
 
 /*
  * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
  *
  * To prevent concurrent destruction or change of range attributes, the
  * svm_read_lock must be held. The caller must not hold the svm_write_lock
  * because that would block concurrent evictions and lead to deadlocks. To
  * serialize concurrent migrations or validations of the same range, the
  * prange->migrate_mutex must be held.
  *
  * For VRAM ranges, the SVM BO must be allocated and valid (protected by its
  * eviction fence.
  *
  * The following sequence ensures race-free validation and GPU mapping:
  *
  * 1. Reserve page table (and SVM BO if range is in VRAM)
  * 2. hmm_range_fault to get page addresses (if system memory)
  * 3. DMA-map pages (if system memory)
  * 4-a. Take notifier lock
  * 4-b. Check that pages still valid (mmu_interval_read_retry)
  * 4-c. Check that the range was not split or otherwise invalidated
  * 4-d. Update GPU page table
  * 4.e. Release notifier lock
  * 5. Release page table (and SVM BO) reservation
  */
 static int svm_range_validate_and_map(struct mm_struct *mm,
                       struct svm_range *prange, int32_t gpuidx,
                       bool intr, bool wait, bool flush_tlb)
 {
     struct svm_validate_context ctx;
     unsigned long start, end, addr;
     struct kfd_process *p;
     void *owner;
     int32_t idx;
     int r = 0;
 
     ctx.process = container_of(prange->svms, struct kfd_process, svms);
     ctx.prange = prange;
     ctx.intr = intr;
 
     if (gpuidx < MAX_GPU_INSTANCE) {
         bitmap_zero(ctx.bitmap, MAX_GPU_INSTANCE);
         bitmap_set(ctx.bitmap, gpuidx, 1);
     } else if (ctx.process->xnack_enabled) {
         bitmap_copy(ctx.bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
 
         /* If prefetch range to GPU, or GPU retry fault migrate range to
          * GPU, which has ACCESS attribute to the range, create mapping
          * on that GPU.
          */
         if (prange->actual_loc) {
             gpuidx = kfd_process_gpuidx_from_gpuid(ctx.process,
                             prange->actual_loc);
             if (gpuidx < 0) {
                 WARN_ONCE(1, "failed get device by id 0x%x\n",
                      prange->actual_loc);
                 return -EINVAL;
             }
             if (test_bit(gpuidx, prange->bitmap_access))
                 bitmap_set(ctx.bitmap, gpuidx, 1);
         }
     } else {
         bitmap_or(ctx.bitmap, prange->bitmap_access,
               prange->bitmap_aip, MAX_GPU_INSTANCE);
     }
 
     if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE)) {
         if (!prange->mapped_to_gpu)
             return 0;
 
         bitmap_copy(ctx.bitmap, prange->bitmap_access, MAX_GPU_INSTANCE);
     }
 
     if (prange->actual_loc && !prange->ttm_res) {
         /* This should never happen. actual_loc gets set by
          * svm_migrate_ram_to_vram after allocating a BO.
          */
         WARN_ONCE(1, "VRAM BO missing during validation\n");
         return -EINVAL;
     }
 
     svm_range_reserve_bos(&ctx);
 
     p = container_of(prange->svms, struct kfd_process, svms);
     owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
                         MAX_GPU_INSTANCE));
     for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
         if (kfd_svm_page_owner(p, idx) != owner) {
             owner = NULL;
             break;
         }
     }
 
     start = prange->start << PAGE_SHIFT;
     end = (prange->last + 1) << PAGE_SHIFT;
     for (addr = start; addr < end && !r; ) {
         struct hmm_range *hmm_range;
         struct vm_area_struct *vma;
         unsigned long next;
         unsigned long offset;
         unsigned long npages;
         bool readonly;
 
         vma = find_vma(mm, addr);
         if (!vma || addr < vma->vm_start) {
             r = -EFAULT;
             goto unreserve_out;
         }
         readonly = !(vma->vm_flags & VM_WRITE);
 
         next = min(vma->vm_end, end);
         npages = (next - addr) >> PAGE_SHIFT;
         WRITE_ONCE(p->svms.faulting_task, current);
         r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
                            addr, npages, &hmm_range,
                            readonly, true, owner);
         WRITE_ONCE(p->svms.faulting_task, NULL);
         if (r) {
             pr_debug("failed %d to get svm range pages\n", r);
             goto unreserve_out;
         }
 
         offset = (addr - start) >> PAGE_SHIFT;
         r = svm_range_dma_map(prange, ctx.bitmap, offset, npages,
                       hmm_range->hmm_pfns);
         if (r) {
             pr_debug("failed %d to dma map range\n", r);
             goto unreserve_out;
         }
 
         svm_range_lock(prange);
         if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
             pr_debug("hmm update the range, need validate again\n");
             r = -EAGAIN;
             goto unlock_out;
         }
         if (!list_empty(&prange->child_list)) {
             pr_debug("range split by unmap in parallel, validate again\n");
             r = -EAGAIN;
             goto unlock_out;
         }
 
         r = svm_range_map_to_gpus(prange, offset, npages, readonly,
                       ctx.bitmap, wait, flush_tlb);
 
 unlock_out:
         svm_range_unlock(prange);
 
         addr = next;
     }
 
     if (addr == end) {
         prange->validated_once = true;
         prange->mapped_to_gpu = true;
     }
 
 unreserve_out:
     svm_range_unreserve_bos(&ctx);
 
     if (!r)
         prange->validate_timestamp = ktime_get_boottime();
 
     return r;
 }
 
 /**
  * svm_range_list_lock_and_flush_work - flush pending deferred work
  *
  * @svms: the svm range list
  * @mm: the mm structure
  *
  * Context: Returns with mmap write lock held, pending deferred work flushed
  *
  */
 void
 svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
                    struct mm_struct *mm)
 {
 retry_flush_work:
     flush_work(&svms->deferred_list_work);
     mmap_write_lock(mm);
 
     if (list_empty(&svms->deferred_range_list))
         return;
     mmap_write_unlock(mm);
     pr_debug("retry flush\n");
     goto retry_flush_work;
 }
 
 static void svm_range_restore_work(struct work_struct *work)
 {
     struct delayed_work *dwork = to_delayed_work(work);
     struct amdkfd_process_info *process_info;
     struct svm_range_list *svms;
     struct svm_range *prange;
     struct kfd_process *p;
     struct mm_struct *mm;
     int evicted_ranges;
     int invalid;
     int r;
 
     svms = container_of(dwork, struct svm_range_list, restore_work);
     evicted_ranges = atomic_read(&svms->evicted_ranges);
     if (!evicted_ranges)
         return;
 
     pr_debug("restore svm ranges\n");
 
     p = container_of(svms, struct kfd_process, svms);
     process_info = p->kgd_process_info;
 
     /* Keep mm reference when svm_range_validate_and_map ranges */
     mm = get_task_mm(p->lead_thread);
     if (!mm) {
         pr_debug("svms 0x%p process mm gone\n", svms);
         return;
     }
 
     mutex_lock(&process_info->lock);
     svm_range_list_lock_and_flush_work(svms, mm);
     mutex_lock(&svms->lock);
 
     evicted_ranges = atomic_read(&svms->evicted_ranges);
 
     list_for_each_entry(prange, &svms->list, list) {
         invalid = atomic_read(&prange->invalid);
         if (!invalid)
             continue;
 
         pr_debug("restoring svms 0x%p prange 0x%p [0x%lx %lx] inv %d\n",
              prange->svms, prange, prange->start, prange->last,
              invalid);
 
         /*
          * If range is migrating, wait for migration is done.
          */
         mutex_lock(&prange->migrate_mutex);
 
         r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
                            false, true, false);
         if (r)
             pr_debug("failed %d to map 0x%lx to gpus\n", r,
                  prange->start);
 
         mutex_unlock(&prange->migrate_mutex);
         if (r)
             goto out_reschedule;
 
         if (atomic_cmpxchg(&prange->invalid, invalid, 0) != invalid)
             goto out_reschedule;
     }
 
     if (atomic_cmpxchg(&svms->evicted_ranges, evicted_ranges, 0) !=
         evicted_ranges)
         goto out_reschedule;
 
     evicted_ranges = 0;
 
     r = kgd2kfd_resume_mm(mm);
     if (r) {
         /* No recovery from this failure. Probably the CP is
          * hanging. No point trying again.
          */
         pr_debug("failed %d to resume KFD\n", r);
     }
 
     pr_debug("restore svm ranges successfully\n");
 
 out_reschedule:
     mutex_unlock(&svms->lock);
     mmap_write_unlock(mm);
     mutex_unlock(&process_info->lock);
 
     /* If validation failed, reschedule another attempt */
     if (evicted_ranges) {
         pr_debug("reschedule to restore svm range\n");
         schedule_delayed_work(&svms->restore_work,
             msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
 
         kfd_smi_event_queue_restore_rescheduled(mm);
     }
     mmput(mm);
 }
 
 /**
  * svm_range_evict - evict svm range
  * @prange: svm range structure
  * @mm: current process mm_struct
  * @start: starting process queue number
  * @last: last process queue number
  *
  * Stop all queues of the process to ensure GPU doesn't access the memory, then
  * return to let CPU evict the buffer and proceed CPU pagetable update.
  *
  * Don't need use lock to sync cpu pagetable invalidation with GPU execution.
  * If invalidation happens while restore work is running, restore work will
  * restart to ensure to get the latest CPU pages mapping to GPU, then start
  * the queues.
  */
 static int
 svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
         unsigned long start, unsigned long last,
         enum mmu_notifier_event event)
 {
     struct svm_range_list *svms = prange->svms;
     struct svm_range *pchild;
     struct kfd_process *p;
     int r = 0;
 
     p = container_of(svms, struct kfd_process, svms);
 
     pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
          svms, prange->start, prange->last, start, last);
 
     if (!p->xnack_enabled ||
         (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) {
         int evicted_ranges;
         bool mapped = prange->mapped_to_gpu;
 
         list_for_each_entry(pchild, &prange->child_list, child_list) {
             if (!pchild->mapped_to_gpu)
                 continue;
             mapped = true;
             mutex_lock_nested(&pchild->lock, 1);
             if (pchild->start <= last && pchild->last >= start) {
                 pr_debug("increment pchild invalid [0x%lx 0x%lx]\n",
                      pchild->start, pchild->last);
                 atomic_inc(&pchild->invalid);
             }
             mutex_unlock(&pchild->lock);
         }
 
         if (!mapped)
             return r;
 
         if (prange->start <= last && prange->last >= start)
             atomic_inc(&prange->invalid);
 
         evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
         if (evicted_ranges != 1)
             return r;
 
         pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
              prange->svms, prange->start, prange->last);
 
         /* First eviction, stop the queues */
         r = kgd2kfd_quiesce_mm(mm, KFD_QUEUE_EVICTION_TRIGGER_SVM);
         if (r)
             pr_debug("failed to quiesce KFD\n");
 
         pr_debug("schedule to restore svm %p ranges\n", svms);
         schedule_delayed_work(&svms->restore_work,
             msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
     } else {
         unsigned long s, l;
         uint32_t trigger;
 
         if (event == MMU_NOTIFY_MIGRATE)
             trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY_MIGRATE;
         else
             trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY;
 
         pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
              prange->svms, start, last);
         list_for_each_entry(pchild, &prange->child_list, child_list) {
             mutex_lock_nested(&pchild->lock, 1);
             s = max(start, pchild->start);
             l = min(last, pchild->last);
             if (l >= s)
                 svm_range_unmap_from_gpus(pchild, s, l, trigger);
             mutex_unlock(&pchild->lock);
         }
         s = max(start, prange->start);
         l = min(last, prange->last);
         if (l >= s)
             svm_range_unmap_from_gpus(prange, s, l, trigger);
     }
 
     return r;
 }
 
 static struct svm_range *svm_range_clone(struct svm_range *old)
 {
     struct svm_range *new;
 
     new = svm_range_new(old->svms, old->start, old->last, false);
     if (!new)
         return NULL;
 
     if (old->svm_bo) {
         new->ttm_res = old->ttm_res;
         new->offset = old->offset;
         new->svm_bo = svm_range_bo_ref(old->svm_bo);
         spin_lock(&new->svm_bo->list_lock);
         list_add(&new->svm_bo_list, &new->svm_bo->range_list);
         spin_unlock(&new->svm_bo->list_lock);
     }
     new->flags = old->flags;
     new->preferred_loc = old->preferred_loc;
     new->prefetch_loc = old->prefetch_loc;
     new->actual_loc = old->actual_loc;
     new->granularity = old->granularity;
     new->mapped_to_gpu = old->mapped_to_gpu;
     bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
     bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
 
     return new;
 }
 
 void svm_range_set_max_pages(struct amdgpu_device *adev)
 {
     uint64_t max_pages;
     uint64_t pages, _pages;
 
     /* 1/32 VRAM size in pages */
     pages = adev->gmc.real_vram_size >> 17;
     pages = clamp(pages, 1ULL << 9, 1ULL << 18);
     pages = rounddown_pow_of_two(pages);
     do {
         max_pages = READ_ONCE(max_svm_range_pages);
         _pages = min_not_zero(max_pages, pages);
     } while (cmpxchg(&max_svm_range_pages, max_pages, _pages) != max_pages);
 }
 
 static int
 svm_range_split_new(struct svm_range_list *svms, uint64_t start, uint64_t last,
             uint64_t max_pages, struct list_head *insert_list,
             struct list_head *update_list)
 {
     struct svm_range *prange;
     uint64_t l;
 
     pr_debug("max_svm_range_pages 0x%llx adding [0x%llx 0x%llx]\n",
          max_pages, start, last);
 
     while (last >= start) {
         l = min(last, ALIGN_DOWN(start + max_pages, max_pages) - 1);
 
         prange = svm_range_new(svms, start, l, true);
         if (!prange)
             return -ENOMEM;
         list_add(&prange->list, insert_list);
         list_add(&prange->update_list, update_list);
 
         start = l + 1;
     }
     return 0;
 }
 
 /**
  * svm_range_add - add svm range and handle overlap
  * @p: the range add to this process svms
  * @start: page size aligned
  * @size: page size aligned
  * @nattr: number of attributes
  * @attrs: array of attributes
  * @update_list: output, the ranges need validate and update GPU mapping
  * @insert_list: output, the ranges need insert to svms
  * @remove_list: output, the ranges are replaced and need remove from svms
  *
  * Check if the virtual address range has overlap with any existing ranges,
  * split partly overlapping ranges and add new ranges in the gaps. All changes
  * should be applied to the range_list and interval tree transactionally. If
  * any range split or allocation fails, the entire update fails. Therefore any
  * existing overlapping svm_ranges are cloned and the original svm_ranges left
  * unchanged.
  *
  * If the transaction succeeds, the caller can update and insert clones and
  * new ranges, then free the originals.
  *
  * Otherwise the caller can free the clones and new ranges, while the old
  * svm_ranges remain unchanged.
  *
  * Context: Process context, caller must hold svms->lock
  *
  * Return:
  * 0 - OK, otherwise error code
  */
 static int
 svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
           uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
           struct list_head *update_list, struct list_head *insert_list,
           struct list_head *remove_list)
 {
     unsigned long last = start + size - 1UL;
     struct svm_range_list *svms = &p->svms;
     struct interval_tree_node *node;
     struct svm_range *prange;
     struct svm_range *tmp;
     struct list_head new_list;
     int r = 0;
 
     pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
 
     INIT_LIST_HEAD(update_list);
     INIT_LIST_HEAD(insert_list);
     INIT_LIST_HEAD(remove_list);
     INIT_LIST_HEAD(&new_list);
 
     node = interval_tree_iter_first(&svms->objects, start, last);
     while (node) {
         struct interval_tree_node *next;
         unsigned long next_start;
 
         pr_debug("found overlap node [0x%lx 0x%lx]\n", node->start,
              node->last);
 
         prange = container_of(node, struct svm_range, it_node);
         next = interval_tree_iter_next(node, start, last);
         next_start = min(node->last, last) + 1;
 
         if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
             /* nothing to do */
         } else if (node->start < start || node->last > last) {
             /* node intersects the update range and its attributes
              * will change. Clone and split it, apply updates only
              * to the overlapping part
              */
             struct svm_range *old = prange;
 
             prange = svm_range_clone(old);
             if (!prange) {
                 r = -ENOMEM;
                 goto out;
             }
 
             list_add(&old->update_list, remove_list);
             list_add(&prange->list, insert_list);
             list_add(&prange->update_list, update_list);
 
             if (node->start < start) {
                 pr_debug("change old range start\n");
                 r = svm_range_split_head(prange, start,
                              insert_list);
                 if (r)
                     goto out;
             }
             if (node->last > last) {
                 pr_debug("change old range last\n");
                 r = svm_range_split_tail(prange, last,
                              insert_list);
                 if (r)
                     goto out;
             }
         } else {
             /* The node is contained within start..last,
              * just update it
              */
             list_add(&prange->update_list, update_list);
         }
 
         /* insert a new node if needed */
         if (node->start > start) {
             r = svm_range_split_new(svms, start, node->start - 1,
                         READ_ONCE(max_svm_range_pages),
                         &new_list, update_list);
             if (r)
                 goto out;
         }
 
         node = next;
         start = next_start;
     }
 
     /* add a final range at the end if needed */
     if (start <= last)
         r = svm_range_split_new(svms, start, last,
                     READ_ONCE(max_svm_range_pages),
                     &new_list, update_list);
 
 out:
     if (r) {
         list_for_each_entry_safe(prange, tmp, insert_list, list)
             svm_range_free(prange, false);
         list_for_each_entry_safe(prange, tmp, &new_list, list)
             svm_range_free(prange, true);
     } else {
         list_splice(&new_list, insert_list);
     }
 
     return r;
 }
 
 static void
 svm_range_update_notifier_and_interval_tree(struct mm_struct *mm,
                         struct svm_range *prange)
 {
     unsigned long start;
     unsigned long last;
 
     start = prange->notifier.interval_tree.start >> PAGE_SHIFT;
     last = prange->notifier.interval_tree.last >> PAGE_SHIFT;
 
     if (prange->start == start && prange->last == last)
         return;
 
     pr_debug("up notifier 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
           prange->svms, prange, start, last, prange->start,
           prange->last);
 
     if (start != 0 && last != 0) {
         interval_tree_remove(&prange->it_node, &prange->svms->objects);
         svm_range_remove_notifier(prange);
     }
     prange->it_node.start = prange->start;
     prange->it_node.last = prange->last;
 
     interval_tree_insert(&prange->it_node, &prange->svms->objects);
     svm_range_add_notifier_locked(mm, prange);
 }
 
 static void
 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange,
              struct mm_struct *mm)
 {
     switch (prange->work_item.op) {
     case SVM_OP_NULL:
         pr_debug("NULL OP 0x%p prange 0x%p [0x%lx 0x%lx]\n",
              svms, prange, prange->start, prange->last);
         break;
     case SVM_OP_UNMAP_RANGE:
         pr_debug("remove 0x%p prange 0x%p [0x%lx 0x%lx]\n",
              svms, prange, prange->start, prange->last);
         svm_range_unlink(prange);
         svm_range_remove_notifier(prange);
         svm_range_free(prange, true);
         break;
     case SVM_OP_UPDATE_RANGE_NOTIFIER:
         pr_debug("update notifier 0x%p prange 0x%p [0x%lx 0x%lx]\n",
              svms, prange, prange->start, prange->last);
         svm_range_update_notifier_and_interval_tree(mm, prange);
         break;
     case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
         pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
              svms, prange, prange->start, prange->last);
         svm_range_update_notifier_and_interval_tree(mm, prange);
         /* TODO: implement deferred validation and mapping */
         break;
     case SVM_OP_ADD_RANGE:
         pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
              prange->start, prange->last);
         svm_range_add_to_svms(prange);
         svm_range_add_notifier_locked(mm, prange);
         break;
     case SVM_OP_ADD_RANGE_AND_MAP:
         pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
              prange, prange->start, prange->last);
         svm_range_add_to_svms(prange);
         svm_range_add_notifier_locked(mm, prange);
         /* TODO: implement deferred validation and mapping */
         break;
     default:
         WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
              prange->work_item.op);
     }
 }
 
 static void svm_range_drain_retry_fault(struct svm_range_list *svms)
 {
     struct kfd_process_device *pdd;
     struct kfd_process *p;
     int drain;
     uint32_t i;
 
     p = container_of(svms, struct kfd_process, svms);
 
 restart:
     drain = atomic_read(&svms->drain_pagefaults);
     if (!drain)
         return;
 
     for_each_set_bit(i, svms->bitmap_supported, p->n_pdds) {
         pdd = p->pdds[i];
         if (!pdd)
             continue;
 
         pr_debug("drain retry fault gpu %d svms %p\n", i, svms);
 
         amdgpu_ih_wait_on_checkpoint_process_ts(pdd->dev->adev,
                              &pdd->dev->adev->irq.ih1);
         pr_debug("drain retry fault gpu %d svms 0x%p done\n", i, svms);
     }
     if (atomic_cmpxchg(&svms->drain_pagefaults, drain, 0) != drain)
         goto restart;
 }
 
 static void svm_range_deferred_list_work(struct work_struct *work)
 {
     struct svm_range_list *svms;
     struct svm_range *prange;
     struct mm_struct *mm;
 
     svms = container_of(work, struct svm_range_list, deferred_list_work);
     pr_debug("enter svms 0x%p\n", svms);
 
     spin_lock(&svms->deferred_list_lock);
     while (!list_empty(&svms->deferred_range_list)) {
         prange = list_first_entry(&svms->deferred_range_list,
                       struct svm_range, deferred_list);
         spin_unlock(&svms->deferred_list_lock);
 
         pr_debug("prange 0x%p [0x%lx 0x%lx] op %d\n", prange,
              prange->start, prange->last, prange->work_item.op);
 
         mm = prange->work_item.mm;
 retry:
         mmap_write_lock(mm);
 
         /* Checking for the need to drain retry faults must be inside
          * mmap write lock to serialize with munmap notifiers.
          */
         if (unlikely(atomic_read(&svms->drain_pagefaults))) {
             mmap_write_unlock(mm);
             svm_range_drain_retry_fault(svms);
             goto retry;
         }
 
         /* Remove from deferred_list must be inside mmap write lock, for
          * two race cases:
          * 1. unmap_from_cpu may change work_item.op and add the range
          *    to deferred_list again, cause use after free bug.
          * 2. svm_range_list_lock_and_flush_work may hold mmap write
          *    lock and continue because deferred_list is empty, but
          *    deferred_list work is actually waiting for mmap lock.
          */
         spin_lock(&svms->deferred_list_lock);
         list_del_init(&prange->deferred_list);
         spin_unlock(&svms->deferred_list_lock);
 
         mutex_lock(&svms->lock);
         mutex_lock(&prange->migrate_mutex);
         while (!list_empty(&prange->child_list)) {
             struct svm_range *pchild;
 
             pchild = list_first_entry(&prange->child_list,
                         struct svm_range, child_list);
             pr_debug("child prange 0x%p op %d\n", pchild,
                  pchild->work_item.op);
             list_del_init(&pchild->child_list);
             svm_range_handle_list_op(svms, pchild, mm);
         }
         mutex_unlock(&prange->migrate_mutex);
 
         svm_range_handle_list_op(svms, prange, mm);
         mutex_unlock(&svms->lock);
         mmap_write_unlock(mm);
 
         /* Pairs with mmget in svm_range_add_list_work */
         mmput(mm);
 
         spin_lock(&svms->deferred_list_lock);
     }
     spin_unlock(&svms->deferred_list_lock);
     pr_debug("exit svms 0x%p\n", svms);
 }
 
 void
 svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
             struct mm_struct *mm, enum svm_work_list_ops op)
 {
     spin_lock(&svms->deferred_list_lock);
     /* if prange is on the deferred list */
     if (!list_empty(&prange->deferred_list)) {
         pr_debug("update exist prange 0x%p work op %d\n", prange, op);
         WARN_ONCE(prange->work_item.mm != mm, "unmatch mm\n");
         if (op != SVM_OP_NULL &&
             prange->work_item.op != SVM_OP_UNMAP_RANGE)
             prange->work_item.op = op;
     } else {
         prange->work_item.op = op;
 
         /* Pairs with mmput in deferred_list_work */
         mmget(mm);
         prange->work_item.mm = mm;
         list_add_tail(&prange->deferred_list,
                   &prange->svms->deferred_range_list);
         pr_debug("add prange 0x%p [0x%lx 0x%lx] to work list op %d\n",
              prange, prange->start, prange->last, op);
     }
     spin_unlock(&svms->deferred_list_lock);
 }
 
 void schedule_deferred_list_work(struct svm_range_list *svms)
 {
     spin_lock(&svms->deferred_list_lock);
     if (!list_empty(&svms->deferred_range_list))
         schedule_work(&svms->deferred_list_work);
     spin_unlock(&svms->deferred_list_lock);
 }
 
 static void
 svm_range_unmap_split(struct mm_struct *mm, struct svm_range *parent,
               struct svm_range *prange, unsigned long start,
               unsigned long last)
 {
     struct svm_range *head;
     struct svm_range *tail;
 
     if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
         pr_debug("prange 0x%p [0x%lx 0x%lx] is already freed\n", prange,
              prange->start, prange->last);
         return;
     }
     if (start > prange->last || last < prange->start)
         return;
 
     head = tail = prange;
     if (start > prange->start)
         svm_range_split(prange, prange->start, start - 1, &tail);
     if (last < tail->last)
         svm_range_split(tail, last + 1, tail->last, &head);
 
     if (head != prange && tail != prange) {
         svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
         svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
     } else if (tail != prange) {
         svm_range_add_child(parent, mm, tail, SVM_OP_UNMAP_RANGE);
     } else if (head != prange) {
         svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
     } else if (parent != prange) {
         prange->work_item.op = SVM_OP_UNMAP_RANGE;
     }
 }
 
 static void
 svm_range_unmap_from_cpu(struct mm_struct *mm, struct svm_range *prange,
              unsigned long start, unsigned long last)
 {
     uint32_t trigger = KFD_SVM_UNMAP_TRIGGER_UNMAP_FROM_CPU;
     struct svm_range_list *svms;
     struct svm_range *pchild;
     struct kfd_process *p;
     unsigned long s, l;
     bool unmap_parent;
 
     p = kfd_lookup_process_by_mm(mm);
     if (!p)
         return;
     svms = &p->svms;
 
     pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n", svms,
          prange, prange->start, prange->last, start, last);
 
     /* Make sure pending page faults are drained in the deferred worker
      * before the range is freed to avoid straggler interrupts on
      * unmapped memory causing "phantom faults".
      */
     atomic_inc(&svms->drain_pagefaults);
 
     unmap_parent = start <= prange->start && last >= prange->last;
 
     list_for_each_entry(pchild, &prange->child_list, child_list) {
         mutex_lock_nested(&pchild->lock, 1);
         s = max(start, pchild->start);
         l = min(last, pchild->last);
         if (l >= s)
             svm_range_unmap_from_gpus(pchild, s, l, trigger);
         svm_range_unmap_split(mm, prange, pchild, start, last);
         mutex_unlock(&pchild->lock);
     }
     s = max(start, prange->start);
     l = min(last, prange->last);
     if (l >= s)
         svm_range_unmap_from_gpus(prange, s, l, trigger);
     svm_range_unmap_split(mm, prange, prange, start, last);
 
     if (unmap_parent)
         svm_range_add_list_work(svms, prange, mm, SVM_OP_UNMAP_RANGE);
     else
         svm_range_add_list_work(svms, prange, mm,
                     SVM_OP_UPDATE_RANGE_NOTIFIER);
     schedule_deferred_list_work(svms);
 
     kfd_unref_process(p);
 }
 
 /**
  * svm_range_cpu_invalidate_pagetables - interval notifier callback
  * @mni: mmu_interval_notifier struct
  * @range: mmu_notifier_range struct
  * @cur_seq: value to pass to mmu_interval_set_seq()
  *
  * If event is MMU_NOTIFY_UNMAP, this is from CPU unmap range, otherwise, it
  * is from migration, or CPU page invalidation callback.
  *
  * For unmap event, unmap range from GPUs, remove prange from svms in a delayed
  * work thread, and split prange if only part of prange is unmapped.
  *
  * For invalidation event, if GPU retry fault is not enabled, evict the queues,
  * then schedule svm_range_restore_work to update GPU mapping and resume queues.
  * If GPU retry fault is enabled, unmap the svm range from GPU, retry fault will
  * update GPU mapping to recover.
  *
  * Context: mmap lock, notifier_invalidate_start lock are held
  *          for invalidate event, prange lock is held if this is from migration
  */
 static bool
 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
                     const struct mmu_notifier_range *range,
                     unsigned long cur_seq)
 {
     struct svm_range *prange;
     unsigned long start;
     unsigned long last;
 
     if (range->event == MMU_NOTIFY_RELEASE)
         return true;
     if (!mmget_not_zero(mni->mm))
         return true;
 
     start = mni->interval_tree.start;
     last = mni->interval_tree.last;
     start = max(start, range->start) >> PAGE_SHIFT;
     last = min(last, range->end - 1) >> PAGE_SHIFT;
     pr_debug("[0x%lx 0x%lx] range[0x%lx 0x%lx] notifier[0x%lx 0x%lx] %d\n",
          start, last, range->start >> PAGE_SHIFT,
          (range->end - 1) >> PAGE_SHIFT,
          mni->interval_tree.start >> PAGE_SHIFT,
          mni->interval_tree.last >> PAGE_SHIFT, range->event);
 
     prange = container_of(mni, struct svm_range, notifier);
 
     svm_range_lock(prange);
     mmu_interval_set_seq(mni, cur_seq);
 
     switch (range->event) {
     case MMU_NOTIFY_UNMAP:
         svm_range_unmap_from_cpu(mni->mm, prange, start, last);
         break;
     default:
         svm_range_evict(prange, mni->mm, start, last, range->event);
         break;
     }
 
     svm_range_unlock(prange);
     mmput(mni->mm);
 
     return true;
 }
 
 /**
  * svm_range_from_addr - find svm range from fault address
  * @svms: svm range list header
  * @addr: address to search range interval tree, in pages
  * @parent: parent range if range is on child list
  *
  * Context: The caller must hold svms->lock
  *
  * Return: the svm_range found or NULL
  */
 struct svm_range *
 svm_range_from_addr(struct svm_range_list *svms, unsigned long addr,
             struct svm_range **parent)
 {
     struct interval_tree_node *node;
     struct svm_range *prange;
     struct svm_range *pchild;
 
     node = interval_tree_iter_first(&svms->objects, addr, addr);
     if (!node)
         return NULL;
 
     prange = container_of(node, struct svm_range, it_node);
     pr_debug("address 0x%lx prange [0x%lx 0x%lx] node [0x%lx 0x%lx]\n",
          addr, prange->start, prange->last, node->start, node->last);
 
     if (addr >= prange->start && addr <= prange->last) {
         if (parent)
             *parent = prange;
         return prange;
     }
     list_for_each_entry(pchild, &prange->child_list, child_list)
         if (addr >= pchild->start && addr <= pchild->last) {
             pr_debug("found address 0x%lx pchild [0x%lx 0x%lx]\n",
                  addr, pchild->start, pchild->last);
             if (parent)
                 *parent = prange;
             return pchild;
         }
 
     return NULL;
 }
 
 /* svm_range_best_restore_location - decide the best fault restore location
  * @prange: svm range structure
  * @adev: the GPU on which vm fault happened
  *
  * This is only called when xnack is on, to decide the best location to restore
  * the range mapping after GPU vm fault. Caller uses the best location to do
  * migration if actual loc is not best location, then update GPU page table
  * mapping to the best location.
  *
  * If the preferred loc is accessible by faulting GPU, use preferred loc.
  * If vm fault gpu idx is on range ACCESSIBLE bitmap, best_loc is vm fault gpu
  * If vm fault gpu idx is on range ACCESSIBLE_IN_PLACE bitmap, then
  *    if range actual loc is cpu, best_loc is cpu
  *    if vm fault gpu is on xgmi same hive of range actual loc gpu, best_loc is
  *    range actual loc.
  * Otherwise, GPU no access, best_loc is -1.
  *
  * Return:
  * -1 means vm fault GPU no access
  * 0 for CPU or GPU id
  */
 static int32_t
 svm_range_best_restore_location(struct svm_range *prange,
                 struct amdgpu_device *adev,
                 int32_t *gpuidx)
 {
     struct amdgpu_device *bo_adev, *preferred_adev;
     struct kfd_process *p;
     uint32_t gpuid;
     int r;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     r = kfd_process_gpuid_from_adev(p, adev, &gpuid, gpuidx);
     if (r < 0) {
         pr_debug("failed to get gpuid from kgd\n");
         return -1;
     }
 
     if (prange->preferred_loc == gpuid ||
         prange->preferred_loc == KFD_IOCTL_SVM_LOCATION_SYSMEM) {
         return prange->preferred_loc;
     } else if (prange->preferred_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
         preferred_adev = svm_range_get_adev_by_id(prange,
                             prange->preferred_loc);
         if (amdgpu_xgmi_same_hive(adev, preferred_adev))
             return prange->preferred_loc;
         /* fall through */
     }
 
     if (test_bit(*gpuidx, prange->bitmap_access))
         return gpuid;
 
     if (test_bit(*gpuidx, prange->bitmap_aip)) {
         if (!prange->actual_loc)
             return 0;
 
         bo_adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
         if (amdgpu_xgmi_same_hive(adev, bo_adev))
             return prange->actual_loc;
         else
             return 0;
     }
 
     return -1;
 }
 
 static int
 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
                    unsigned long *start, unsigned long *last,
                    bool *is_heap_stack)
 {
     struct vm_area_struct *vma;
     struct interval_tree_node *node;
     unsigned long start_limit, end_limit;
 
     vma = find_vma(p->mm, addr << PAGE_SHIFT);
     if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
         pr_debug("VMA does not exist in address [0x%llx]\n", addr);
         return -EFAULT;
     }
 
     *is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
               vma->vm_end >= vma->vm_mm->start_brk) ||
              (vma->vm_start <= vma->vm_mm->start_stack &&
               vma->vm_end >= vma->vm_mm->start_stack);
 
     start_limit = max(vma->vm_start >> PAGE_SHIFT,
               (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
     end_limit = min(vma->vm_end >> PAGE_SHIFT,
             (unsigned long)ALIGN(addr + 1, 2UL << 8));
     /* First range that starts after the fault address */
     node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);
     if (node) {
         end_limit = min(end_limit, node->start);
         /* Last range that ends before the fault address */
         node = container_of(rb_prev(&node->rb),
                     struct interval_tree_node, rb);
     } else {
         /* Last range must end before addr because
          * there was no range after addr
          */
         node = container_of(rb_last(&p->svms.objects.rb_root),
                     struct interval_tree_node, rb);
     }
     if (node) {
         if (node->last >= addr) {
             WARN(1, "Overlap with prev node and page fault addr\n");
             return -EFAULT;
         }
         start_limit = max(start_limit, node->last + 1);
     }
 
     *start = start_limit;
     *last = end_limit - 1;
 
     pr_debug("vma [0x%lx 0x%lx] range [0x%lx 0x%lx] is_heap_stack %d\n",
          vma->vm_start >> PAGE_SHIFT, vma->vm_end >> PAGE_SHIFT,
          *start, *last, *is_heap_stack);
 
     return 0;
 }
 
 static int
 svm_range_check_vm_userptr(struct kfd_process *p, uint64_t start, uint64_t last,
                uint64_t *bo_s, uint64_t *bo_l)
 {
     struct amdgpu_bo_va_mapping *mapping;
     struct interval_tree_node *node;
     struct amdgpu_bo *bo = NULL;
     unsigned long userptr;
     uint32_t i;
     int r;
 
     for (i = 0; i < p->n_pdds; i++) {
         struct amdgpu_vm *vm;
 
         if (!p->pdds[i]->drm_priv)
             continue;
 
         vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
         r = amdgpu_bo_reserve(vm->root.bo, false);
         if (r)
             return r;
 
         /* Check userptr by searching entire vm->va interval tree */
         node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
         while (node) {
             mapping = container_of((struct rb_node *)node,
                            struct amdgpu_bo_va_mapping, rb);
             bo = mapping->bo_va->base.bo;
 
             if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
                              start << PAGE_SHIFT,
                              last << PAGE_SHIFT,
                              &userptr)) {
                 node = interval_tree_iter_next(node, 0, ~0ULL);
                 continue;
             }
 
             pr_debug("[0x%llx 0x%llx] already userptr mapped\n",
                  start, last);
             if (bo_s && bo_l) {
                 *bo_s = userptr >> PAGE_SHIFT;
                 *bo_l = *bo_s + bo->tbo.ttm->num_pages - 1;
             }
             amdgpu_bo_unreserve(vm->root.bo);
             return -EADDRINUSE;
         }
         amdgpu_bo_unreserve(vm->root.bo);
     }
     return 0;
 }
 
 static struct
 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
                         struct kfd_process *p,
                         struct mm_struct *mm,
                         int64_t addr)
 {
     struct svm_range *prange = NULL;
     unsigned long start, last;
     uint32_t gpuid, gpuidx;
     bool is_heap_stack;
     uint64_t bo_s = 0;
     uint64_t bo_l = 0;
     int r;
 
     if (svm_range_get_range_boundaries(p, addr, &start, &last,
                        &is_heap_stack))
         return NULL;
 
     r = svm_range_check_vm(p, start, last, &bo_s, &bo_l);
     if (r != -EADDRINUSE)
         r = svm_range_check_vm_userptr(p, start, last, &bo_s, &bo_l);
 
     if (r == -EADDRINUSE) {
         if (addr >= bo_s && addr <= bo_l)
             return NULL;
 
         /* Create one page svm range if 2MB range overlapping */
         start = addr;
         last = addr;
     }
 
     prange = svm_range_new(&p->svms, start, last, true);
     if (!prange) {
         pr_debug("Failed to create prange in address [0x%llx]\n", addr);
         return NULL;
     }
     if (kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx)) {
         pr_debug("failed to get gpuid from kgd\n");
         svm_range_free(prange, true);
         return NULL;
     }
 
     if (is_heap_stack)
         prange->preferred_loc = KFD_IOCTL_SVM_LOCATION_SYSMEM;
 
     svm_range_add_to_svms(prange);
     svm_range_add_notifier_locked(mm, prange);
 
     return prange;
 }
 
 /* svm_range_skip_recover - decide if prange can be recovered
  * @prange: svm range structure
  *
  * GPU vm retry fault handle skip recover the range for cases:
  * 1. prange is on deferred list to be removed after unmap, it is stale fault,
  *    deferred list work will drain the stale fault before free the prange.
  * 2. prange is on deferred list to add interval notifier after split, or
  * 3. prange is child range, it is split from parent prange, recover later
  *    after interval notifier is added.
  *
  * Return: true to skip recover, false to recover
  */
 static bool svm_range_skip_recover(struct svm_range *prange)
 {
     struct svm_range_list *svms = prange->svms;
 
     spin_lock(&svms->deferred_list_lock);
     if (list_empty(&prange->deferred_list) &&
         list_empty(&prange->child_list)) {
         spin_unlock(&svms->deferred_list_lock);
         return false;
     }
     spin_unlock(&svms->deferred_list_lock);
 
     if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
         pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] unmapped\n",
              svms, prange, prange->start, prange->last);
         return true;
     }
     if (prange->work_item.op == SVM_OP_ADD_RANGE_AND_MAP ||
         prange->work_item.op == SVM_OP_ADD_RANGE) {
         pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] not added yet\n",
              svms, prange, prange->start, prange->last);
         return true;
     }
     return false;
 }
 
 static void
 svm_range_count_fault(struct amdgpu_device *adev, struct kfd_process *p,
               int32_t gpuidx)
 {
     struct kfd_process_device *pdd;
 
     /* fault is on different page of same range
      * or fault is skipped to recover later
      * or fault is on invalid virtual address
      */
     if (gpuidx == MAX_GPU_INSTANCE) {
         uint32_t gpuid;
         int r;
 
         r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx);
         if (r < 0)
             return;
     }
 
     /* fault is recovered
      * or fault cannot recover because GPU no access on the range
      */
     pdd = kfd_process_device_from_gpuidx(p, gpuidx);
     if (pdd)
         WRITE_ONCE(pdd->faults, pdd->faults + 1);
 }
 
 static bool
 svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
 {
     unsigned long requested = VM_READ;
 
     if (write_fault)
         requested |= VM_WRITE;
 
     pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
         vma->vm_flags);
     return (vma->vm_flags & requested) == requested;
 }
 
 int
 svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
             uint64_t addr, bool write_fault)
 {
     struct mm_struct *mm = NULL;
     struct svm_range_list *svms;
     struct svm_range *prange;
     struct kfd_process *p;
     ktime_t timestamp = ktime_get_boottime();
     int32_t best_loc;
     int32_t gpuidx = MAX_GPU_INSTANCE;
     bool write_locked = false;
     struct vm_area_struct *vma;
     bool migration = false;
     int r = 0;
 
     if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
         pr_debug("device does not support SVM\n");
         return -EFAULT;
     }
 
     p = kfd_lookup_process_by_pasid(pasid);
     if (!p) {
         pr_debug("kfd process not founded pasid 0x%x\n", pasid);
         return 0;
     }
     svms = &p->svms;
 
     pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
 
     if (atomic_read(&svms->drain_pagefaults)) {
         pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
         r = 0;
         goto out;
     }
 
     if (!p->xnack_enabled) {
         pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
         r = -EFAULT;
         goto out;
     }
 
     /* p->lead_thread is available as kfd_process_wq_release flush the work
      * before releasing task ref.
      */
     mm = get_task_mm(p->lead_thread);
     if (!mm) {
         pr_debug("svms 0x%p failed to get mm\n", svms);
         r = 0;
         goto out;
     }
 
     mmap_read_lock(mm);
 retry_write_locked:
     mutex_lock(&svms->lock);
     prange = svm_range_from_addr(svms, addr, NULL);
     if (!prange) {
         pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
              svms, addr);
         if (!write_locked) {
             /* Need the write lock to create new range with MMU notifier.
              * Also flush pending deferred work to make sure the interval
              * tree is up to date before we add a new range
              */
             mutex_unlock(&svms->lock);
             mmap_read_unlock(mm);
             mmap_write_lock(mm);
             write_locked = true;
             goto retry_write_locked;
         }
         prange = svm_range_create_unregistered_range(adev, p, mm, addr);
         if (!prange) {
             pr_debug("failed to create unregistered range svms 0x%p address [0x%llx]\n",
                  svms, addr);
             mmap_write_downgrade(mm);
             r = -EFAULT;
             goto out_unlock_svms;
         }
     }
     if (write_locked)
         mmap_write_downgrade(mm);
 
     mutex_lock(&prange->migrate_mutex);
 
     if (svm_range_skip_recover(prange)) {
         amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
         r = 0;
         goto out_unlock_range;
     }
 
     /* skip duplicate vm fault on different pages of same range */
     if (ktime_before(timestamp, ktime_add_ns(prange->validate_timestamp,
                 AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING))) {
         pr_debug("svms 0x%p [0x%lx %lx] already restored\n",
              svms, prange->start, prange->last);
         r = 0;
         goto out_unlock_range;
     }
 
     /* __do_munmap removed VMA, return success as we are handling stale
      * retry fault.
      */
     vma = find_vma(mm, addr << PAGE_SHIFT);
     if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
         pr_debug("address 0x%llx VMA is removed\n", addr);
         r = 0;
         goto out_unlock_range;
     }
 
     if (!svm_fault_allowed(vma, write_fault)) {
         pr_debug("fault addr 0x%llx no %s permission\n", addr,
             write_fault ? "write" : "read");
         r = -EPERM;
         goto out_unlock_range;
     }
 
     best_loc = svm_range_best_restore_location(prange, adev, &gpuidx);
     if (best_loc == -1) {
         pr_debug("svms %p failed get best restore loc [0x%lx 0x%lx]\n",
              svms, prange->start, prange->last);
         r = -EACCES;
         goto out_unlock_range;
     }
 
     pr_debug("svms %p [0x%lx 0x%lx] best restore 0x%x, actual loc 0x%x\n",
          svms, prange->start, prange->last, best_loc,
          prange->actual_loc);
 
     kfd_smi_event_page_fault_start(adev->kfd.dev, p->lead_thread->pid, addr,
                        write_fault, timestamp);
 
     if (prange->actual_loc != best_loc) {
         migration = true;
         if (best_loc) {
             r = svm_migrate_to_vram(prange, best_loc, mm,
                     KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
             if (r) {
                 pr_debug("svm_migrate_to_vram failed (%d) at %llx, falling back to system memory\n",
                      r, addr);
                 /* Fallback to system memory if migration to
                  * VRAM failed
                  */
                 if (prange->actual_loc)
                     r = svm_migrate_vram_to_ram(prange, mm,
                        KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
                 else
                     r = 0;
             }
         } else {
             r = svm_migrate_vram_to_ram(prange, mm,
                     KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
         }
         if (r) {
             pr_debug("failed %d to migrate svms %p [0x%lx 0x%lx]\n",
                  r, svms, prange->start, prange->last);
             goto out_unlock_range;
         }
     }
 
     r = svm_range_validate_and_map(mm, prange, gpuidx, false, false, false);
     if (r)
         pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
              r, svms, prange->start, prange->last);
 
     kfd_smi_event_page_fault_end(adev->kfd.dev, p->lead_thread->pid, addr,
                      migration);
 
 out_unlock_range:
     mutex_unlock(&prange->migrate_mutex);
 out_unlock_svms:
     mutex_unlock(&svms->lock);
     mmap_read_unlock(mm);
 
     svm_range_count_fault(adev, p, gpuidx);
 
     mmput(mm);
 out:
     kfd_unref_process(p);
 
     if (r == -EAGAIN) {
         pr_debug("recover vm fault later\n");
         amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
         r = 0;
     }
     return r;
 }
 
 void svm_range_list_fini(struct kfd_process *p)
 {
     struct svm_range *prange;
     struct svm_range *next;
 
     pr_debug("pasid 0x%x svms 0x%p\n", p->pasid, &p->svms);
 
     cancel_delayed_work_sync(&p->svms.restore_work);
 
     /* Ensure list work is finished before process is destroyed */
     flush_work(&p->svms.deferred_list_work);
 
     /*
      * Ensure no retry fault comes in afterwards, as page fault handler will
      * not find kfd process and take mm lock to recover fault.
      */
     atomic_inc(&p->svms.drain_pagefaults);
     svm_range_drain_retry_fault(&p->svms);
 
     list_for_each_entry_safe(prange, next, &p->svms.list, list) {
         svm_range_unlink(prange);
         svm_range_remove_notifier(prange);
         svm_range_free(prange, true);
     }
 
     mutex_destroy(&p->svms.lock);
 
     pr_debug("pasid 0x%x svms 0x%p done\n", p->pasid, &p->svms);
 }
 
 int svm_range_list_init(struct kfd_process *p)
 {
     struct svm_range_list *svms = &p->svms;
     int i;
 
     svms->objects = RB_ROOT_CACHED;
     mutex_init(&svms->lock);
     INIT_LIST_HEAD(&svms->list);
     atomic_set(&svms->evicted_ranges, 0);
     atomic_set(&svms->drain_pagefaults, 0);
     INIT_DELAYED_WORK(&svms->restore_work, svm_range_restore_work);
     INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work);
     INIT_LIST_HEAD(&svms->deferred_range_list);
     INIT_LIST_HEAD(&svms->criu_svm_metadata_list);
     spin_lock_init(&svms->deferred_list_lock);
 
     for (i = 0; i < p->n_pdds; i++)
         if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev))
             bitmap_set(svms->bitmap_supported, i, 1);
 
     return 0;
 }
 
 /**
  * svm_range_check_vm - check if virtual address range mapped already
  * @p: current kfd_process
  * @start: range start address, in pages
  * @last: range last address, in pages
  * @bo_s: mapping start address in pages if address range already mapped
  * @bo_l: mapping last address in pages if address range already mapped
  *
  * The purpose is to avoid virtual address ranges already allocated by
  * kfd_ioctl_alloc_memory_of_gpu ioctl.
  * It looks for each pdd in the kfd_process.
  *
  * Context: Process context
  *
  * Return 0 - OK, if the range is not mapped.
  * Otherwise error code:
  * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
  * a signal. Release all buffer reservations and return to user-space.
  */
 static int
 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
            uint64_t *bo_s, uint64_t *bo_l)
 {
     struct amdgpu_bo_va_mapping *mapping;
     struct interval_tree_node *node;
     uint32_t i;
     int r;
 
     for (i = 0; i < p->n_pdds; i++) {
         struct amdgpu_vm *vm;
 
         if (!p->pdds[i]->drm_priv)
             continue;
 
         vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
         r = amdgpu_bo_reserve(vm->root.bo, false);
         if (r)
             return r;
 
         node = interval_tree_iter_first(&vm->va, start, last);
         if (node) {
             pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
                  start, last);
             mapping = container_of((struct rb_node *)node,
                            struct amdgpu_bo_va_mapping, rb);
             if (bo_s && bo_l) {
                 *bo_s = mapping->start;
                 *bo_l = mapping->last;
             }
             amdgpu_bo_unreserve(vm->root.bo);
             return -EADDRINUSE;
         }
         amdgpu_bo_unreserve(vm->root.bo);
     }
 
     return 0;
 }
 
 /**
  * svm_range_is_valid - check if virtual address range is valid
  * @p: current kfd_process
  * @start: range start address, in pages
  * @size: range size, in pages
  *
  * Valid virtual address range means it belongs to one or more VMAs
  *
  * Context: Process context
  *
  * Return:
  *  0 - OK, otherwise error code
  */
 static int
 svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
 {
     const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
     struct vm_area_struct *vma;
     unsigned long end;
     unsigned long start_unchg = start;
 
     start <<= PAGE_SHIFT;
     end = start + (size << PAGE_SHIFT);
     do {
         vma = find_vma(p->mm, start);
         if (!vma || start < vma->vm_start ||
             (vma->vm_flags & device_vma))
             return -EFAULT;
         start = min(end, vma->vm_end);
     } while (start < end);
 
     return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT, NULL,
                   NULL);
 }
 
 /**
  * svm_range_best_prefetch_location - decide the best prefetch location
  * @prange: svm range structure
  *
  * For xnack off:
  * If range map to single GPU, the best prefetch location is prefetch_loc, which
  * can be CPU or GPU.
  *
  * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on
  * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise
  * the best prefetch location is always CPU, because GPU can not have coherent
  * mapping VRAM of other GPUs even with large-BAR PCIe connection.
  *
  * For xnack on:
  * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is
  * prefetch_loc, other GPU access will generate vm fault and trigger migration.
  *
  * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same
  * hive, the best prefetch location is prefetch_loc GPU, otherwise the best
  * prefetch location is always CPU.
  *
  * Context: Process context
  *
  * Return:
  * 0 for CPU or GPU id
  */
 static uint32_t
 svm_range_best_prefetch_location(struct svm_range *prange)
 {
     DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
     uint32_t best_loc = prange->prefetch_loc;
     struct kfd_process_device *pdd;
     struct amdgpu_device *bo_adev;
     struct kfd_process *p;
     uint32_t gpuidx;
 
     p = container_of(prange->svms, struct kfd_process, svms);
 
     if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED)
         goto out;
 
     bo_adev = svm_range_get_adev_by_id(prange, best_loc);
     if (!bo_adev) {
         WARN_ONCE(1, "failed to get device by id 0x%x\n", best_loc);
         best_loc = 0;
         goto out;
     }
 
     if (p->xnack_enabled)
         bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
     else
         bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
               MAX_GPU_INSTANCE);
 
     for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
         pdd = kfd_process_device_from_gpuidx(p, gpuidx);
         if (!pdd) {
             pr_debug("failed to get device by idx 0x%x\n", gpuidx);
             continue;
         }
 
         if (pdd->dev->adev == bo_adev)
             continue;
 
         if (!amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
             best_loc = 0;
             break;
         }
     }
 
 out:
     pr_debug("xnack %d svms 0x%p [0x%lx 0x%lx] best loc 0x%x\n",
          p->xnack_enabled, &p->svms, prange->start, prange->last,
          best_loc);
 
     return best_loc;
 }
 
 /* FIXME: This is a workaround for page locking bug when some pages are
  * invalid during migration to VRAM
  */
 void svm_range_prefault(struct svm_range *prange, struct mm_struct *mm,
             void *owner)
 {
     struct hmm_range *hmm_range;
     int r;
 
     if (prange->validated_once)
         return;
 
     r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
                        prange->start << PAGE_SHIFT,
                        prange->npages, &hmm_range,
                        false, true, owner);
     if (!r) {
         amdgpu_hmm_range_get_pages_done(hmm_range);
         prange->validated_once = true;
     }
 }
 
 /* svm_range_trigger_migration - start page migration if prefetch loc changed
  * @mm: current process mm_struct
  * @prange: svm range structure
  * @migrated: output, true if migration is triggered
  *
  * If range perfetch_loc is GPU, actual loc is cpu 0, then migrate the range
  * from ram to vram.
  * If range prefetch_loc is cpu 0, actual loc is GPU, then migrate the range
  * from vram to ram.
  *
  * If GPU vm fault retry is not enabled, migration interact with MMU notifier
  * and restore work:
  * 1. migrate_vma_setup invalidate pages, MMU notifier callback svm_range_evict
  *    stops all queues, schedule restore work
  * 2. svm_range_restore_work wait for migration is done by
  *    a. svm_range_validate_vram takes prange->migrate_mutex
  *    b. svm_range_validate_ram HMM get pages wait for CPU fault handle returns
  * 3. restore work update mappings of GPU, resume all queues.
  *
  * Context: Process context
  *
  * Return:
  * 0 - OK, otherwise - error code of migration
  */
 static int
 svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
                 bool *migrated)
 {
     uint32_t best_loc;
     int r = 0;
 
     *migrated = false;
     best_loc = svm_range_best_prefetch_location(prange);
 
     if (best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
         best_loc == prange->actual_loc)
         return 0;
 
     if (!best_loc) {
         r = svm_migrate_vram_to_ram(prange, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
         *migrated = !r;
         return r;
     }
 
     r = svm_migrate_to_vram(prange, best_loc, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
     *migrated = !r;
 
     return r;
 }
 
 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
 {
     if (!fence)
         return -EINVAL;
 
     if (dma_fence_is_signaled(&fence->base))
         return 0;
 
     if (fence->svm_bo) {
         WRITE_ONCE(fence->svm_bo->evicting, 1);
         schedule_work(&fence->svm_bo->eviction_work);
     }
 
     return 0;
 }
 
 static void svm_range_evict_svm_bo_worker(struct work_struct *work)
 {
     struct svm_range_bo *svm_bo;
     struct mm_struct *mm;
     int r = 0;
 
     svm_bo = container_of(work, struct svm_range_bo, eviction_work);
     if (!svm_bo_ref_unless_zero(svm_bo))
         return; /* svm_bo was freed while eviction was pending */
 
     if (mmget_not_zero(svm_bo->eviction_fence->mm)) {
         mm = svm_bo->eviction_fence->mm;
     } else {
         svm_range_bo_unref(svm_bo);
         return;
     }
 
     mmap_read_lock(mm);
     spin_lock(&svm_bo->list_lock);
     while (!list_empty(&svm_bo->range_list) && !r) {
         struct svm_range *prange =
                 list_first_entry(&svm_bo->range_list,
                         struct svm_range, svm_bo_list);
         int retries = 3;
 
         list_del_init(&prange->svm_bo_list);
         spin_unlock(&svm_bo->list_lock);
 
         pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
              prange->start, prange->last);
 
         mutex_lock(&prange->migrate_mutex);
         do {
             r = svm_migrate_vram_to_ram(prange, mm,
                         KFD_MIGRATE_TRIGGER_TTM_EVICTION);
         } while (!r && prange->actual_loc && --retries);
 
         if (!r && prange->actual_loc)
             pr_info_once("Migration failed during eviction");
 
         if (!prange->actual_loc) {
             mutex_lock(&prange->lock);
             prange->svm_bo = NULL;
             mutex_unlock(&prange->lock);
         }
         mutex_unlock(&prange->migrate_mutex);
 
         spin_lock(&svm_bo->list_lock);
     }
     spin_unlock(&svm_bo->list_lock);
     mmap_read_unlock(mm);
     mmput(mm);
 
     dma_fence_signal(&svm_bo->eviction_fence->base);
 
     /* This is the last reference to svm_bo, after svm_range_vram_node_free
      * has been called in svm_migrate_vram_to_ram
      */
     WARN_ONCE(!r && kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
     svm_range_bo_unref(svm_bo);
 }
 
 static int
 svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
            uint64_t start, uint64_t size, uint32_t nattr,
            struct kfd_ioctl_svm_attribute *attrs)
 {
     struct amdkfd_process_info *process_info = p->kgd_process_info;
     struct list_head update_list;
     struct list_head insert_list;
     struct list_head remove_list;
     struct svm_range_list *svms;
     struct svm_range *prange;
     struct svm_range *next;
     bool update_mapping = false;
     bool flush_tlb;
     int r = 0;
 
     pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
          p->pasid, &p->svms, start, start + size - 1, size);
 
     r = svm_range_check_attr(p, nattr, attrs);
     if (r)
         return r;
 
     svms = &p->svms;
 
     mutex_lock(&process_info->lock);
 
     svm_range_list_lock_and_flush_work(svms, mm);
 
     r = svm_range_is_valid(p, start, size);
     if (r) {
         pr_debug("invalid range r=%d\n", r);
         mmap_write_unlock(mm);
         goto out;
     }
 
     mutex_lock(&svms->lock);
 
     /* Add new range and split existing ranges as needed */
     r = svm_range_add(p, start, size, nattr, attrs, &update_list,
               &insert_list, &remove_list);
     if (r) {
         mutex_unlock(&svms->lock);
         mmap_write_unlock(mm);
         goto out;
     }
     /* Apply changes as a transaction */
     list_for_each_entry_safe(prange, next, &insert_list, list) {
         svm_range_add_to_svms(prange);
         svm_range_add_notifier_locked(mm, prange);
     }
     list_for_each_entry(prange, &update_list, update_list) {
         svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
         /* TODO: unmap ranges from GPU that lost access */
     }
     list_for_each_entry_safe(prange, next, &remove_list, update_list) {
         pr_debug("unlink old 0x%p prange 0x%p [0x%lx 0x%lx]\n",
              prange->svms, prange, prange->start,
              prange->last);
         svm_range_unlink(prange);
         svm_range_remove_notifier(prange);
         svm_range_free(prange, false);
     }
 
     mmap_write_downgrade(mm);
     /* Trigger migrations and revalidate and map to GPUs as needed. If
      * this fails we may be left with partially completed actions. There
      * is no clean way of rolling back to the previous state in such a
      * case because the rollback wouldn't be guaranteed to work either.
      */
     list_for_each_entry(prange, &update_list, update_list) {
         bool migrated;
 
         mutex_lock(&prange->migrate_mutex);
 
         r = svm_range_trigger_migration(mm, prange, &migrated);
         if (r)
             goto out_unlock_range;
 
         if (migrated && (!p->xnack_enabled ||
             (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) &&
             prange->mapped_to_gpu) {
             pr_debug("restore_work will update mappings of GPUs\n");
             mutex_unlock(&prange->migrate_mutex);
             continue;
         }
 
         if (!migrated && !update_mapping) {
             mutex_unlock(&prange->migrate_mutex);
             continue;
         }
 
         flush_tlb = !migrated && update_mapping && prange->mapped_to_gpu;
 
         r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
                            true, true, flush_tlb);
         if (r)
             pr_debug("failed %d to map svm range\n", r);
 
 out_unlock_range:
         mutex_unlock(&prange->migrate_mutex);
         if (r)
             break;
     }
 
     svm_range_debug_dump(svms);
 
     mutex_unlock(&svms->lock);
     mmap_read_unlock(mm);
 out:
     mutex_unlock(&process_info->lock);
 
     pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
          &p->svms, start, start + size - 1, r);
 
     return r;
 }
 
 static int
 svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm,
            uint64_t start, uint64_t size, uint32_t nattr,
            struct kfd_ioctl_svm_attribute *attrs)
 {
     DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
     DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
     bool get_preferred_loc = false;
     bool get_prefetch_loc = false;
     bool get_granularity = false;
     bool get_accessible = false;
     bool get_flags = false;
     uint64_t last = start + size - 1UL;
     uint8_t granularity = 0xff;
     struct interval_tree_node *node;
     struct svm_range_list *svms;
     struct svm_range *prange;
     uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
     uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
     uint32_t flags_and = 0xffffffff;
     uint32_t flags_or = 0;
     int gpuidx;
     uint32_t i;
     int r = 0;
 
     pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
          start + size - 1, nattr);
 
     /* Flush pending deferred work to avoid racing with deferred actions from
      * previous memory map changes (e.g. munmap). Concurrent memory map changes
      * can still race with get_attr because we don't hold the mmap lock. But that
      * would be a race condition in the application anyway, and undefined
      * behaviour is acceptable in that case.
      */
     flush_work(&p->svms.deferred_list_work);
 
     mmap_read_lock(mm);
     r = svm_range_is_valid(p, start, size);
     mmap_read_unlock(mm);
     if (r) {
         pr_debug("invalid range r=%d\n", r);
         return r;
     }
 
     for (i = 0; i < nattr; i++) {
         switch (attrs[i].type) {
         case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
             get_preferred_loc = true;
             break;
         case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
             get_prefetch_loc = true;
             break;
         case KFD_IOCTL_SVM_ATTR_ACCESS:
             get_accessible = true;
             break;
         case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
         case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
             get_flags = true;
             break;
         case KFD_IOCTL_SVM_ATTR_GRANULARITY:
             get_granularity = true;
             break;
         case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
         case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
             fallthrough;
         default:
             pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
             return -EINVAL;
         }
     }
 
     svms = &p->svms;
 
     mutex_lock(&svms->lock);
 
     node = interval_tree_iter_first(&svms->objects, start, last);
     if (!node) {
         pr_debug("range attrs not found return default values\n");
         svm_range_set_default_attributes(&location, &prefetch_loc,
                          &granularity, &flags_and);
         flags_or = flags_and;
         if (p->xnack_enabled)
             bitmap_copy(bitmap_access, svms->bitmap_supported,
                     MAX_GPU_INSTANCE);
         else
             bitmap_zero(bitmap_access, MAX_GPU_INSTANCE);
         bitmap_zero(bitmap_aip, MAX_GPU_INSTANCE);
         goto fill_values;
     }
     bitmap_copy(bitmap_access, svms->bitmap_supported, MAX_GPU_INSTANCE);
     bitmap_copy(bitmap_aip, svms->bitmap_supported, MAX_GPU_INSTANCE);
 
     while (node) {
         struct interval_tree_node *next;
 
         prange = container_of(node, struct svm_range, it_node);
         next = interval_tree_iter_next(node, start, last);
 
         if (get_preferred_loc) {
             if (prange->preferred_loc ==
                     KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
                 (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
                  location != prange->preferred_loc)) {
                 location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
                 get_preferred_loc = false;
             } else {
                 location = prange->preferred_loc;
             }
         }
         if (get_prefetch_loc) {
             if (prange->prefetch_loc ==
                     KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
                 (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
                  prefetch_loc != prange->prefetch_loc)) {
                 prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
                 get_prefetch_loc = false;
             } else {
                 prefetch_loc = prange->prefetch_loc;
             }
         }
         if (get_accessible) {
             bitmap_and(bitmap_access, bitmap_access,
                    prange->bitmap_access, MAX_GPU_INSTANCE);
             bitmap_and(bitmap_aip, bitmap_aip,
                    prange->bitmap_aip, MAX_GPU_INSTANCE);
         }
         if (get_flags) {
             flags_and &= prange->flags;
             flags_or |= prange->flags;
         }
 
         if (get_granularity && prange->granularity < granularity)
             granularity = prange->granularity;
 
         node = next;
     }
 fill_values:
     mutex_unlock(&svms->lock);
 
     for (i = 0; i < nattr; i++) {
         switch (attrs[i].type) {
         case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
             attrs[i].value = location;
             break;
         case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
             attrs[i].value = prefetch_loc;
             break;
         case KFD_IOCTL_SVM_ATTR_ACCESS:
             gpuidx = kfd_process_gpuidx_from_gpuid(p,
                                    attrs[i].value);
             if (gpuidx < 0) {
                 pr_debug("invalid gpuid %x\n", attrs[i].value);
                 return -EINVAL;
             }
             if (test_bit(gpuidx, bitmap_access))
                 attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
             else if (test_bit(gpuidx, bitmap_aip))
                 attrs[i].type =
                     KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
             else
                 attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
             break;
         case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
             attrs[i].value = flags_and;
             break;
         case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
             attrs[i].value = ~flags_or;
             break;
         case KFD_IOCTL_SVM_ATTR_GRANULARITY:
             attrs[i].value = (uint32_t)granularity;
             break;
         }
     }
 
     return 0;
 }
 
 int kfd_criu_resume_svm(struct kfd_process *p)
 {
     struct kfd_ioctl_svm_attribute *set_attr_new, *set_attr = NULL;
     int nattr_common = 4, nattr_accessibility = 1;
     struct criu_svm_metadata *criu_svm_md = NULL;
     struct svm_range_list *svms = &p->svms;
     struct criu_svm_metadata *next = NULL;
     uint32_t set_flags = 0xffffffff;
     int i, j, num_attrs, ret = 0;
     uint64_t set_attr_size;
     struct mm_struct *mm;
 
     if (list_empty(&svms->criu_svm_metadata_list)) {
         pr_debug("No SVM data from CRIU restore stage 2\n");
         return ret;
     }
 
     mm = get_task_mm(p->lead_thread);
     if (!mm) {
         pr_err("failed to get mm for the target process\n");
         return -ESRCH;
     }
 
     num_attrs = nattr_common + (nattr_accessibility * p->n_pdds);
 
     i = j = 0;
     list_for_each_entry(criu_svm_md, &svms->criu_svm_metadata_list, list) {
         pr_debug("criu_svm_md[%d]\n\tstart: 0x%llx size: 0x%llx (npages)\n",
              i, criu_svm_md->data.start_addr, criu_svm_md->data.size);
 
         for (j = 0; j < num_attrs; j++) {
             pr_debug("\ncriu_svm_md[%d]->attrs[%d].type : 0x%x\ncriu_svm_md[%d]->attrs[%d].value : 0x%x\n",
                  i, j, criu_svm_md->data.attrs[j].type,
                  i, j, criu_svm_md->data.attrs[j].value);
             switch (criu_svm_md->data.attrs[j].type) {
             /* During Checkpoint operation, the query for
              * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC attribute might
              * return KFD_IOCTL_SVM_LOCATION_UNDEFINED if they were
              * not used by the range which was checkpointed. Care
              * must be taken to not restore with an invalid value
              * otherwise the gpuidx value will be invalid and
              * set_attr would eventually fail so just replace those
              * with another dummy attribute such as
              * KFD_IOCTL_SVM_ATTR_SET_FLAGS.
              */
             case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
                 if (criu_svm_md->data.attrs[j].value ==
                     KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
                     criu_svm_md->data.attrs[j].type =
                         KFD_IOCTL_SVM_ATTR_SET_FLAGS;
                     criu_svm_md->data.attrs[j].value = 0;
                 }
                 break;
             case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
                 set_flags = criu_svm_md->data.attrs[j].value;
                 break;
             default:
                 break;
             }
         }
 
         /* CLR_FLAGS is not available via get_attr during checkpoint but
          * it needs to be inserted before restoring the ranges so
          * allocate extra space for it before calling set_attr
          */
         set_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
                         (num_attrs + 1);
         set_attr_new = krealloc(set_attr, set_attr_size,
                         GFP_KERNEL);
         if (!set_attr_new) {
             ret = -ENOMEM;
             goto exit;
         }
         set_attr = set_attr_new;
 
         memcpy(set_attr, criu_svm_md->data.attrs, num_attrs *
                     sizeof(struct kfd_ioctl_svm_attribute));
         set_attr[num_attrs].type = KFD_IOCTL_SVM_ATTR_CLR_FLAGS;
         set_attr[num_attrs].value = ~set_flags;
 
         ret = svm_range_set_attr(p, mm, criu_svm_md->data.start_addr,
                      criu_svm_md->data.size, num_attrs + 1,
                      set_attr);
         if (ret) {
             pr_err("CRIU: failed to set range attributes\n");
             goto exit;
         }
 
         i++;
     }
 exit:
     kfree(set_attr);
     list_for_each_entry_safe(criu_svm_md, next, &svms->criu_svm_metadata_list, list) {
         pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
                         criu_svm_md->data.start_addr);
         kfree(criu_svm_md);
     }
 
     mmput(mm);
     return ret;
 
 }
 
 int kfd_criu_restore_svm(struct kfd_process *p,
              uint8_t __user *user_priv_ptr,
              uint64_t *priv_data_offset,
              uint64_t max_priv_data_size)
 {
     uint64_t svm_priv_data_size, svm_object_md_size, svm_attrs_size;
     int nattr_common = 4, nattr_accessibility = 1;
     struct criu_svm_metadata *criu_svm_md = NULL;
     struct svm_range_list *svms = &p->svms;
     uint32_t num_devices;
     int ret = 0;
 
     num_devices = p->n_pdds;
     /* Handle one SVM range object at a time, also the number of gpus are
      * assumed to be same on the restore node, checking must be done while
      * evaluating the topology earlier
      */
 
     svm_attrs_size = sizeof(struct kfd_ioctl_svm_attribute) *
         (nattr_common + nattr_accessibility * num_devices);
     svm_object_md_size = sizeof(struct criu_svm_metadata) + svm_attrs_size;
 
     svm_priv_data_size = sizeof(struct kfd_criu_svm_range_priv_data) +
                                 svm_attrs_size;
 
     criu_svm_md = kzalloc(svm_object_md_size, GFP_KERNEL);
     if (!criu_svm_md) {
         pr_err("failed to allocate memory to store svm metadata\n");
         return -ENOMEM;
     }
     if (*priv_data_offset + svm_priv_data_size > max_priv_data_size) {
         ret = -EINVAL;
         goto exit;
     }
 
     ret = copy_from_user(&criu_svm_md->data, user_priv_ptr + *priv_data_offset,
                  svm_priv_data_size);
     if (ret) {
         ret = -EFAULT;
         goto exit;
     }
     *priv_data_offset += svm_priv_data_size;
 
     list_add_tail(&criu_svm_md->list, &svms->criu_svm_metadata_list);
 
     return 0;
 
 
 exit:
     kfree(criu_svm_md);
     return ret;
 }
 
 int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
                uint64_t *svm_priv_data_size)
 {
     uint64_t total_size, accessibility_size, common_attr_size;
     int nattr_common = 4, nattr_accessibility = 1;
     int num_devices = p->n_pdds;
     struct svm_range_list *svms;
     struct svm_range *prange;
     uint32_t count = 0;
 
     *svm_priv_data_size = 0;
 
     svms = &p->svms;
     if (!svms)
         return -EINVAL;
 
     mutex_lock(&svms->lock);
     list_for_each_entry(prange, &svms->list, list) {
         pr_debug("prange: 0x%p start: 0x%lx\t npages: 0x%llx\t end: 0x%llx\n",
              prange, prange->start, prange->npages,
              prange->start + prange->npages - 1);
         count++;
     }
     mutex_unlock(&svms->lock);
 
     *num_svm_ranges = count;
     /* Only the accessbility attributes need to be queried for all the gpus
      * individually, remaining ones are spanned across the entire process
      * regardless of the various gpu nodes. Of the remaining attributes,
      * KFD_IOCTL_SVM_ATTR_CLR_FLAGS need not be saved.
      *
      * KFD_IOCTL_SVM_ATTR_PREFERRED_LOC
      * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC
      * KFD_IOCTL_SVM_ATTR_SET_FLAGS
      * KFD_IOCTL_SVM_ATTR_GRANULARITY
      *
      * ** ACCESSBILITY ATTRIBUTES **
      * (Considered as one, type is altered during query, value is gpuid)
      * KFD_IOCTL_SVM_ATTR_ACCESS
      * KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE
      * KFD_IOCTL_SVM_ATTR_NO_ACCESS
      */
     if (*num_svm_ranges > 0) {
         common_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
             nattr_common;
         accessibility_size = sizeof(struct kfd_ioctl_svm_attribute) *
             nattr_accessibility * num_devices;
 
         total_size = sizeof(struct kfd_criu_svm_range_priv_data) +
             common_attr_size + accessibility_size;
 
         *svm_priv_data_size = *num_svm_ranges * total_size;
     }
 
     pr_debug("num_svm_ranges %u total_priv_size %llu\n", *num_svm_ranges,
          *svm_priv_data_size);
     return 0;
 }
 
 int kfd_criu_checkpoint_svm(struct kfd_process *p,
                 uint8_t __user *user_priv_data,
                 uint64_t *priv_data_offset)
 {
     struct kfd_criu_svm_range_priv_data *svm_priv = NULL;
     struct kfd_ioctl_svm_attribute *query_attr = NULL;
     uint64_t svm_priv_data_size, query_attr_size = 0;
     int index, nattr_common = 4, ret = 0;
     struct svm_range_list *svms;
     int num_devices = p->n_pdds;
     struct svm_range *prange;
     struct mm_struct *mm;
 
     svms = &p->svms;
     if (!svms)
         return -EINVAL;
 
     mm = get_task_mm(p->lead_thread);
     if (!mm) {
         pr_err("failed to get mm for the target process\n");
         return -ESRCH;
     }
 
     query_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
                 (nattr_common + num_devices);
 
     query_attr = kzalloc(query_attr_size, GFP_KERNEL);
     if (!query_attr) {
         ret = -ENOMEM;
         goto exit;
     }
 
     query_attr[0].type = KFD_IOCTL_SVM_ATTR_PREFERRED_LOC;
     query_attr[1].type = KFD_IOCTL_SVM_ATTR_PREFETCH_LOC;
     query_attr[2].type = KFD_IOCTL_SVM_ATTR_SET_FLAGS;
     query_attr[3].type = KFD_IOCTL_SVM_ATTR_GRANULARITY;
 
     for (index = 0; index < num_devices; index++) {
         struct kfd_process_device *pdd = p->pdds[index];
 
         query_attr[index + nattr_common].type =
             KFD_IOCTL_SVM_ATTR_ACCESS;
         query_attr[index + nattr_common].value = pdd->user_gpu_id;
     }
 
     svm_priv_data_size = sizeof(*svm_priv) + query_attr_size;
 
     svm_priv = kzalloc(svm_priv_data_size, GFP_KERNEL);
     if (!svm_priv) {
         ret = -ENOMEM;
         goto exit_query;
     }
 
     index = 0;
     list_for_each_entry(prange, &svms->list, list) {
 
         svm_priv->object_type = KFD_CRIU_OBJECT_TYPE_SVM_RANGE;
         svm_priv->start_addr = prange->start;
         svm_priv->size = prange->npages;
         memcpy(&svm_priv->attrs, query_attr, query_attr_size);
         pr_debug("CRIU: prange: 0x%p start: 0x%lx\t npages: 0x%llx end: 0x%llx\t size: 0x%llx\n",
              prange, prange->start, prange->npages,
              prange->start + prange->npages - 1,
              prange->npages * PAGE_SIZE);
 
         ret = svm_range_get_attr(p, mm, svm_priv->start_addr,
                      svm_priv->size,
                      (nattr_common + num_devices),
                      svm_priv->attrs);
         if (ret) {
             pr_err("CRIU: failed to obtain range attributes\n");
             goto exit_priv;
         }
 
         if (copy_to_user(user_priv_data + *priv_data_offset, svm_priv,
                  svm_priv_data_size)) {
             pr_err("Failed to copy svm priv to user\n");
             ret = -EFAULT;
             goto exit_priv;
         }
 
         *priv_data_offset += svm_priv_data_size;
 
     }
 
 
 exit_priv:
     kfree(svm_priv);
 exit_query:
     kfree(query_attr);
 exit:
     mmput(mm);
     return ret;
 }
 
 int
 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
       uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
 {
     struct mm_struct *mm = current->mm;
     int r;
 
     start >>= PAGE_SHIFT;
     size >>= PAGE_SHIFT;
 
     switch (op) {
     case KFD_IOCTL_SVM_OP_SET_ATTR:
         r = svm_range_set_attr(p, mm, start, size, nattrs, attrs);
         break;
     case KFD_IOCTL_SVM_OP_GET_ATTR:
         r = svm_range_get_attr(p, mm, start, size, nattrs, attrs);
         break;
     default:
         r = EINVAL;
         break;
     }
 
     return r;
 }