OSCL-LXR linux-6.0.1/​arch/​powerpc/​platforms/​pseries/​vio.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-later
 /*
  * IBM PowerPC Virtual I/O Infrastructure Support.
  *
  *    Copyright (c) 2003,2008 IBM Corp.
  *     Dave Engebretsen engebret@us.ibm.com
  *     Santiago Leon santil@us.ibm.com
  *     Hollis Blanchard <hollisb@us.ibm.com>
  *     Stephen Rothwell
  *     Robert Jennings <rcjenn@us.ibm.com>
  */
 
 #include <linux/cpu.h>
 #include <linux/types.h>
 #include <linux/delay.h>
 #include <linux/stat.h>
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/console.h>
 #include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/dma-map-ops.h>
 #include <linux/kobject.h>
 #include <linux/kexec.h>
 #include <linux/of_irq.h>
 
 #include <asm/iommu.h>
 #include <asm/dma.h>
 #include <asm/vio.h>
 #include <asm/prom.h>
 #include <asm/firmware.h>
 #include <asm/tce.h>
 #include <asm/page.h>
 #include <asm/hvcall.h>
 #include <asm/machdep.h>
 
 static struct vio_dev vio_bus_device  = { /* fake "parent" device */
     .name = "vio",
     .type = "",
     .dev.init_name = "vio",
     .dev.bus = &vio_bus_type,
 };
 
 #ifdef CONFIG_PPC_SMLPAR
 /**
  * vio_cmo_pool - A pool of IO memory for CMO use
  *
  * @size: The size of the pool in bytes
  * @free: The amount of free memory in the pool
  */
 struct vio_cmo_pool {
     size_t size;
     size_t free;
 };
 
 /* How many ms to delay queued balance work */
 #define VIO_CMO_BALANCE_DELAY 100
 
 /* Portion out IO memory to CMO devices by this chunk size */
 #define VIO_CMO_BALANCE_CHUNK 131072
 
 /**
  * vio_cmo_dev_entry - A device that is CMO-enabled and requires entitlement
  *
  * @vio_dev: struct vio_dev pointer
  * @list: pointer to other devices on bus that are being tracked
  */
 struct vio_cmo_dev_entry {
     struct vio_dev *viodev;
     struct list_head list;
 };
 
 /**
  * vio_cmo - VIO bus accounting structure for CMO entitlement
  *
  * @lock: spinlock for entire structure
  * @balance_q: work queue for balancing system entitlement
  * @device_list: list of CMO-enabled devices requiring entitlement
  * @entitled: total system entitlement in bytes
  * @reserve: pool of memory from which devices reserve entitlement, incl. spare
  * @excess: pool of excess entitlement not needed for device reserves or spare
  * @spare: IO memory for device hotplug functionality
  * @min: minimum necessary for system operation
  * @desired: desired memory for system operation
  * @curr: bytes currently allocated
  * @high: high water mark for IO data usage
  */
 static struct vio_cmo {
     spinlock_t lock;
     struct delayed_work balance_q;
     struct list_head device_list;
     size_t entitled;
     struct vio_cmo_pool reserve;
     struct vio_cmo_pool excess;
     size_t spare;
     size_t min;
     size_t desired;
     size_t curr;
     size_t high;
 } vio_cmo;
 
 /**
  * vio_cmo_OF_devices - Count the number of OF devices that have DMA windows
  */
 static int vio_cmo_num_OF_devs(void)
 {
     struct device_node *node_vroot;
     int count = 0;
 
     /*
      * Count the number of vdevice entries with an
      * ibm,my-dma-window OF property
      */
     node_vroot = of_find_node_by_name(NULL, "vdevice");
     if (node_vroot) {
         struct device_node *of_node;
         struct property *prop;
 
         for_each_child_of_node(node_vroot, of_node) {
             prop = of_find_property(of_node, "ibm,my-dma-window",
                                    NULL);
             if (prop)
                 count++;
         }
     }
     of_node_put(node_vroot);
     return count;
 }
 
 /**
  * vio_cmo_alloc - allocate IO memory for CMO-enable devices
  *
  * @viodev: VIO device requesting IO memory
  * @size: size of allocation requested
  *
  * Allocations come from memory reserved for the devices and any excess
  * IO memory available to all devices.  The spare pool used to service
  * hotplug must be equal to %VIO_CMO_MIN_ENT for the excess pool to be
  * made available.
  *
  * Return codes:
  *  0 for successful allocation and -ENOMEM for a failure
  */
 static inline int vio_cmo_alloc(struct vio_dev *viodev, size_t size)
 {
     unsigned long flags;
     size_t reserve_free = 0;
     size_t excess_free = 0;
     int ret = -ENOMEM;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
 
     /* Determine the amount of free entitlement available in reserve */
     if (viodev->cmo.entitled > viodev->cmo.allocated)
         reserve_free = viodev->cmo.entitled - viodev->cmo.allocated;
 
     /* If spare is not fulfilled, the excess pool can not be used. */
     if (vio_cmo.spare >= VIO_CMO_MIN_ENT)
         excess_free = vio_cmo.excess.free;
 
     /* The request can be satisfied */
     if ((reserve_free + excess_free) >= size) {
         vio_cmo.curr += size;
         if (vio_cmo.curr > vio_cmo.high)
             vio_cmo.high = vio_cmo.curr;
         viodev->cmo.allocated += size;
         size -= min(reserve_free, size);
         vio_cmo.excess.free -= size;
         ret = 0;
     }
 
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
     return ret;
 }
 
 /**
  * vio_cmo_dealloc - deallocate IO memory from CMO-enable devices
  * @viodev: VIO device freeing IO memory
  * @size: size of deallocation
  *
  * IO memory is freed by the device back to the correct memory pools.
  * The spare pool is replenished first from either memory pool, then
  * the reserve pool is used to reduce device entitlement, the excess
  * pool is used to increase the reserve pool toward the desired entitlement
  * target, and then the remaining memory is returned to the pools.
  *
  */
 static inline void vio_cmo_dealloc(struct vio_dev *viodev, size_t size)
 {
     unsigned long flags;
     size_t spare_needed = 0;
     size_t excess_freed = 0;
     size_t reserve_freed = size;
     size_t tmp;
     int balance = 0;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
     vio_cmo.curr -= size;
 
     /* Amount of memory freed from the excess pool */
     if (viodev->cmo.allocated > viodev->cmo.entitled) {
         excess_freed = min(reserve_freed, (viodev->cmo.allocated -
                                            viodev->cmo.entitled));
         reserve_freed -= excess_freed;
     }
 
     /* Remove allocation from device */
     viodev->cmo.allocated -= (reserve_freed + excess_freed);
 
     /* Spare is a subset of the reserve pool, replenish it first. */
     spare_needed = VIO_CMO_MIN_ENT - vio_cmo.spare;
 
     /*
      * Replenish the spare in the reserve pool from the excess pool.
      * This moves entitlement into the reserve pool.
      */
     if (spare_needed && excess_freed) {
         tmp = min(excess_freed, spare_needed);
         vio_cmo.excess.size -= tmp;
         vio_cmo.reserve.size += tmp;
         vio_cmo.spare += tmp;
         excess_freed -= tmp;
         spare_needed -= tmp;
         balance = 1;
     }
 
     /*
      * Replenish the spare in the reserve pool from the reserve pool.
      * This removes entitlement from the device down to VIO_CMO_MIN_ENT,
      * if needed, and gives it to the spare pool. The amount of used
      * memory in this pool does not change.
      */
     if (spare_needed && reserve_freed) {
         tmp = min3(spare_needed, reserve_freed, (viodev->cmo.entitled - VIO_CMO_MIN_ENT));
 
         vio_cmo.spare += tmp;
         viodev->cmo.entitled -= tmp;
         reserve_freed -= tmp;
         spare_needed -= tmp;
         balance = 1;
     }
 
     /*
      * Increase the reserve pool until the desired allocation is met.
      * Move an allocation freed from the excess pool into the reserve
      * pool and schedule a balance operation.
      */
     if (excess_freed && (vio_cmo.desired > vio_cmo.reserve.size)) {
         tmp = min(excess_freed, (vio_cmo.desired - vio_cmo.reserve.size));
 
         vio_cmo.excess.size -= tmp;
         vio_cmo.reserve.size += tmp;
         excess_freed -= tmp;
         balance = 1;
     }
 
     /* Return memory from the excess pool to that pool */
     if (excess_freed)
         vio_cmo.excess.free += excess_freed;
 
     if (balance)
         schedule_delayed_work(&vio_cmo.balance_q, VIO_CMO_BALANCE_DELAY);
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
 }
 
 /**
  * vio_cmo_entitlement_update - Manage system entitlement changes
  *
  * @new_entitlement: new system entitlement to attempt to accommodate
  *
  * Increases in entitlement will be used to fulfill the spare entitlement
  * and the rest is given to the excess pool.  Decreases, if they are
  * possible, come from the excess pool and from unused device entitlement
  *
  * Returns: 0 on success, -ENOMEM when change can not be made
  */
 int vio_cmo_entitlement_update(size_t new_entitlement)
 {
     struct vio_dev *viodev;
     struct vio_cmo_dev_entry *dev_ent;
     unsigned long flags;
     size_t avail, delta, tmp;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
 
     /* Entitlement increases */
     if (new_entitlement > vio_cmo.entitled) {
         delta = new_entitlement - vio_cmo.entitled;
 
         /* Fulfill spare allocation */
         if (vio_cmo.spare < VIO_CMO_MIN_ENT) {
             tmp = min(delta, (VIO_CMO_MIN_ENT - vio_cmo.spare));
             vio_cmo.spare += tmp;
             vio_cmo.reserve.size += tmp;
             delta -= tmp;
         }
 
         /* Remaining new allocation goes to the excess pool */
         vio_cmo.entitled += delta;
         vio_cmo.excess.size += delta;
         vio_cmo.excess.free += delta;
 
         goto out;
     }
 
     /* Entitlement decreases */
     delta = vio_cmo.entitled - new_entitlement;
     avail = vio_cmo.excess.free;
 
     /*
      * Need to check how much unused entitlement each device can
      * sacrifice to fulfill entitlement change.
      */
     list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
         if (avail >= delta)
             break;
 
         viodev = dev_ent->viodev;
         if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
             (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
                 avail += viodev->cmo.entitled -
                          max_t(size_t, viodev->cmo.allocated,
                                VIO_CMO_MIN_ENT);
     }
 
     if (delta <= avail) {
         vio_cmo.entitled -= delta;
 
         /* Take entitlement from the excess pool first */
         tmp = min(vio_cmo.excess.free, delta);
         vio_cmo.excess.size -= tmp;
         vio_cmo.excess.free -= tmp;
         delta -= tmp;
 
         /*
          * Remove all but VIO_CMO_MIN_ENT bytes from devices
          * until entitlement change is served
          */
         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
             if (!delta)
                 break;
 
             viodev = dev_ent->viodev;
             tmp = 0;
             if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
                 (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
                 tmp = viodev->cmo.entitled -
                       max_t(size_t, viodev->cmo.allocated,
                             VIO_CMO_MIN_ENT);
             viodev->cmo.entitled -= min(tmp, delta);
             delta -= min(tmp, delta);
         }
     } else {
         spin_unlock_irqrestore(&vio_cmo.lock, flags);
         return -ENOMEM;
     }
 
 out:
     schedule_delayed_work(&vio_cmo.balance_q, 0);
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
     return 0;
 }
 
 /**
  * vio_cmo_balance - Balance entitlement among devices
  *
  * @work: work queue structure for this operation
  *
  * Any system entitlement above the minimum needed for devices, or
  * already allocated to devices, can be distributed to the devices.
  * The list of devices is iterated through to recalculate the desired
  * entitlement level and to determine how much entitlement above the
  * minimum entitlement is allocated to devices.
  *
  * Small chunks of the available entitlement are given to devices until
  * their requirements are fulfilled or there is no entitlement left to give.
  * Upon completion sizes of the reserve and excess pools are calculated.
  *
  * The system minimum entitlement level is also recalculated here.
  * Entitlement will be reserved for devices even after vio_bus_remove to
  * accommodate reloading the driver.  The OF tree is walked to count the
  * number of devices present and this will remove entitlement for devices
  * that have actually left the system after having vio_bus_remove called.
  */
 static void vio_cmo_balance(struct work_struct *work)
 {
     struct vio_cmo *cmo;
     struct vio_dev *viodev;
     struct vio_cmo_dev_entry *dev_ent;
     unsigned long flags;
     size_t avail = 0, level, chunk, need;
     int devcount = 0, fulfilled;
 
     cmo = container_of(work, struct vio_cmo, balance_q.work);
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
 
     /* Calculate minimum entitlement and fulfill spare */
     cmo->min = vio_cmo_num_OF_devs() * VIO_CMO_MIN_ENT;
     BUG_ON(cmo->min > cmo->entitled);
     cmo->spare = min_t(size_t, VIO_CMO_MIN_ENT, (cmo->entitled - cmo->min));
     cmo->min += cmo->spare;
     cmo->desired = cmo->min;
 
     /*
      * Determine how much entitlement is available and reset device
      * entitlements
      */
     avail = cmo->entitled - cmo->spare;
     list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
         viodev = dev_ent->viodev;
         devcount++;
         viodev->cmo.entitled = VIO_CMO_MIN_ENT;
         cmo->desired += (viodev->cmo.desired - VIO_CMO_MIN_ENT);
         avail -= max_t(size_t, viodev->cmo.allocated, VIO_CMO_MIN_ENT);
     }
 
     /*
      * Having provided each device with the minimum entitlement, loop
      * over the devices portioning out the remaining entitlement
      * until there is nothing left.
      */
     level = VIO_CMO_MIN_ENT;
     while (avail) {
         fulfilled = 0;
         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
             viodev = dev_ent->viodev;
 
             if (viodev->cmo.desired <= level) {
                 fulfilled++;
                 continue;
             }
 
             /*
              * Give the device up to VIO_CMO_BALANCE_CHUNK
              * bytes of entitlement, but do not exceed the
              * desired level of entitlement for the device.
              */
             chunk = min_t(size_t, avail, VIO_CMO_BALANCE_CHUNK);
             chunk = min(chunk, (viodev->cmo.desired -
                                 viodev->cmo.entitled));
             viodev->cmo.entitled += chunk;
 
             /*
              * If the memory for this entitlement increase was
              * already allocated to the device it does not come
              * from the available pool being portioned out.
              */
             need = max(viodev->cmo.allocated, viodev->cmo.entitled)-
                    max(viodev->cmo.allocated, level);
             avail -= need;
 
         }
         if (fulfilled == devcount)
             break;
         level += VIO_CMO_BALANCE_CHUNK;
     }
 
     /* Calculate new reserve and excess pool sizes */
     cmo->reserve.size = cmo->min;
     cmo->excess.free = 0;
     cmo->excess.size = 0;
     need = 0;
     list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
         viodev = dev_ent->viodev;
         /* Calculated reserve size above the minimum entitlement */
         if (viodev->cmo.entitled)
             cmo->reserve.size += (viodev->cmo.entitled -
                                   VIO_CMO_MIN_ENT);
         /* Calculated used excess entitlement */
         if (viodev->cmo.allocated > viodev->cmo.entitled)
             need += viodev->cmo.allocated - viodev->cmo.entitled;
     }
     cmo->excess.size = cmo->entitled - cmo->reserve.size;
     cmo->excess.free = cmo->excess.size - need;
 
     cancel_delayed_work(to_delayed_work(work));
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
 }
 
 static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size,
                       dma_addr_t *dma_handle, gfp_t flag,
                       unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     void *ret;
 
     if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) {
         atomic_inc(&viodev->cmo.allocs_failed);
         return NULL;
     }
 
     ret = iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
                     dma_handle, dev->coherent_dma_mask, flag,
                     dev_to_node(dev));
     if (unlikely(ret == NULL)) {
         vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
         atomic_inc(&viodev->cmo.allocs_failed);
     }
 
     return ret;
 }
 
 static void vio_dma_iommu_free_coherent(struct device *dev, size_t size,
                     void *vaddr, dma_addr_t dma_handle,
                     unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
 
     iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle);
     vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
 }
 
 static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page,
                                          unsigned long offset, size_t size,
                                          enum dma_data_direction direction,
                                          unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct iommu_table *tbl = get_iommu_table_base(dev);
     dma_addr_t ret = DMA_MAPPING_ERROR;
 
     if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl))))
         goto out_fail;
     ret = iommu_map_page(dev, tbl, page, offset, size, dma_get_mask(dev),
             direction, attrs);
     if (unlikely(ret == DMA_MAPPING_ERROR))
         goto out_deallocate;
     return ret;
 
 out_deallocate:
     vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 out_fail:
     atomic_inc(&viodev->cmo.allocs_failed);
     return DMA_MAPPING_ERROR;
 }
 
 static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
                      size_t size,
                      enum dma_data_direction direction,
                      unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct iommu_table *tbl = get_iommu_table_base(dev);
 
     iommu_unmap_page(tbl, dma_handle, size, direction, attrs);
     vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 }
 
 static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
                                 int nelems, enum dma_data_direction direction,
                                 unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct iommu_table *tbl = get_iommu_table_base(dev);
     struct scatterlist *sgl;
     int ret, count;
     size_t alloc_size = 0;
 
     for_each_sg(sglist, sgl, nelems, count)
         alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl));
 
     ret = vio_cmo_alloc(viodev, alloc_size);
     if (ret)
         goto out_fail;
     ret = ppc_iommu_map_sg(dev, tbl, sglist, nelems, dma_get_mask(dev),
             direction, attrs);
     if (unlikely(!ret))
         goto out_deallocate;
 
     for_each_sg(sglist, sgl, ret, count)
         alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
     if (alloc_size)
         vio_cmo_dealloc(viodev, alloc_size);
     return ret;
 
 out_deallocate:
     vio_cmo_dealloc(viodev, alloc_size);
 out_fail:
     atomic_inc(&viodev->cmo.allocs_failed);
     return ret;
 }
 
 static void vio_dma_iommu_unmap_sg(struct device *dev,
         struct scatterlist *sglist, int nelems,
         enum dma_data_direction direction,
         unsigned long attrs)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct iommu_table *tbl = get_iommu_table_base(dev);
     struct scatterlist *sgl;
     size_t alloc_size = 0;
     int count;
 
     for_each_sg(sglist, sgl, nelems, count)
         alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
 
     ppc_iommu_unmap_sg(tbl, sglist, nelems, direction, attrs);
     vio_cmo_dealloc(viodev, alloc_size);
 }
 
 static const struct dma_map_ops vio_dma_mapping_ops = {
     .alloc             = vio_dma_iommu_alloc_coherent,
     .free              = vio_dma_iommu_free_coherent,
     .map_sg            = vio_dma_iommu_map_sg,
     .unmap_sg          = vio_dma_iommu_unmap_sg,
     .map_page          = vio_dma_iommu_map_page,
     .unmap_page        = vio_dma_iommu_unmap_page,
     .dma_supported     = dma_iommu_dma_supported,
     .get_required_mask = dma_iommu_get_required_mask,
     .mmap          = dma_common_mmap,
     .get_sgtable       = dma_common_get_sgtable,
     .alloc_pages       = dma_common_alloc_pages,
     .free_pages    = dma_common_free_pages,
 };
 
 /**
  * vio_cmo_set_dev_desired - Set desired entitlement for a device
  *
  * @viodev: struct vio_dev for device to alter
  * @desired: new desired entitlement level in bytes
  *
  * For use by devices to request a change to their entitlement at runtime or
  * through sysfs.  The desired entitlement level is changed and a balancing
  * of system resources is scheduled to run in the future.
  */
 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
 {
     unsigned long flags;
     struct vio_cmo_dev_entry *dev_ent;
     int found = 0;
 
     if (!firmware_has_feature(FW_FEATURE_CMO))
         return;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
     if (desired < VIO_CMO_MIN_ENT)
         desired = VIO_CMO_MIN_ENT;
 
     /*
      * Changes will not be made for devices not in the device list.
      * If it is not in the device list, then no driver is loaded
      * for the device and it can not receive entitlement.
      */
     list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
         if (viodev == dev_ent->viodev) {
             found = 1;
             break;
         }
     if (!found) {
         spin_unlock_irqrestore(&vio_cmo.lock, flags);
         return;
     }
 
     /* Increase/decrease in desired device entitlement */
     if (desired >= viodev->cmo.desired) {
         /* Just bump the bus and device values prior to a balance*/
         vio_cmo.desired += desired - viodev->cmo.desired;
         viodev->cmo.desired = desired;
     } else {
         /* Decrease bus and device values for desired entitlement */
         vio_cmo.desired -= viodev->cmo.desired - desired;
         viodev->cmo.desired = desired;
         /*
          * If less entitlement is desired than current entitlement, move
          * any reserve memory in the change region to the excess pool.
          */
         if (viodev->cmo.entitled > desired) {
             vio_cmo.reserve.size -= viodev->cmo.entitled - desired;
             vio_cmo.excess.size += viodev->cmo.entitled - desired;
             /*
              * If entitlement moving from the reserve pool to the
              * excess pool is currently unused, add to the excess
              * free counter.
              */
             if (viodev->cmo.allocated < viodev->cmo.entitled)
                 vio_cmo.excess.free += viodev->cmo.entitled -
                                        max(viodev->cmo.allocated, desired);
             viodev->cmo.entitled = desired;
         }
     }
     schedule_delayed_work(&vio_cmo.balance_q, 0);
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
 }
 
 /**
  * vio_cmo_bus_probe - Handle CMO specific bus probe activities
  *
  * @viodev - Pointer to struct vio_dev for device
  *
  * Determine the devices IO memory entitlement needs, attempting
  * to satisfy the system minimum entitlement at first and scheduling
  * a balance operation to take care of the rest at a later time.
  *
  * Returns: 0 on success, -EINVAL when device doesn't support CMO, and
  *          -ENOMEM when entitlement is not available for device or
  *          device entry.
  *
  */
 static int vio_cmo_bus_probe(struct vio_dev *viodev)
 {
     struct vio_cmo_dev_entry *dev_ent;
     struct device *dev = &viodev->dev;
     struct iommu_table *tbl;
     struct vio_driver *viodrv = to_vio_driver(dev->driver);
     unsigned long flags;
     size_t size;
     bool dma_capable = false;
 
     tbl = get_iommu_table_base(dev);
 
     /* A device requires entitlement if it has a DMA window property */
     switch (viodev->family) {
     case VDEVICE:
         if (of_get_property(viodev->dev.of_node,
                     "ibm,my-dma-window", NULL))
             dma_capable = true;
         break;
     case PFO:
         dma_capable = false;
         break;
     default:
         dev_warn(dev, "unknown device family: %d\n", viodev->family);
         BUG();
         break;
     }
 
     /* Configure entitlement for the device. */
     if (dma_capable) {
         /* Check that the driver is CMO enabled and get desired DMA */
         if (!viodrv->get_desired_dma) {
             dev_err(dev, "%s: device driver does not support CMO\n",
                     __func__);
             return -EINVAL;
         }
 
         viodev->cmo.desired =
             IOMMU_PAGE_ALIGN(viodrv->get_desired_dma(viodev), tbl);
         if (viodev->cmo.desired < VIO_CMO_MIN_ENT)
             viodev->cmo.desired = VIO_CMO_MIN_ENT;
         size = VIO_CMO_MIN_ENT;
 
         dev_ent = kmalloc(sizeof(struct vio_cmo_dev_entry),
                           GFP_KERNEL);
         if (!dev_ent)
             return -ENOMEM;
 
         dev_ent->viodev = viodev;
         spin_lock_irqsave(&vio_cmo.lock, flags);
         list_add(&dev_ent->list, &vio_cmo.device_list);
     } else {
         viodev->cmo.desired = 0;
         size = 0;
         spin_lock_irqsave(&vio_cmo.lock, flags);
     }
 
     /*
      * If the needs for vio_cmo.min have not changed since they
      * were last set, the number of devices in the OF tree has
      * been constant and the IO memory for this is already in
      * the reserve pool.
      */
     if (vio_cmo.min == ((vio_cmo_num_OF_devs() + 1) *
                         VIO_CMO_MIN_ENT)) {
         /* Updated desired entitlement if device requires it */
         if (size)
             vio_cmo.desired += (viodev->cmo.desired -
                                 VIO_CMO_MIN_ENT);
     } else {
         size_t tmp;
 
         tmp = vio_cmo.spare + vio_cmo.excess.free;
         if (tmp < size) {
             dev_err(dev, "%s: insufficient free "
                     "entitlement to add device. "
                     "Need %lu, have %lu\n", __func__,
                 size, (vio_cmo.spare + tmp));
             spin_unlock_irqrestore(&vio_cmo.lock, flags);
             return -ENOMEM;
         }
 
         /* Use excess pool first to fulfill request */
         tmp = min(size, vio_cmo.excess.free);
         vio_cmo.excess.free -= tmp;
         vio_cmo.excess.size -= tmp;
         vio_cmo.reserve.size += tmp;
 
         /* Use spare if excess pool was insufficient */
         vio_cmo.spare -= size - tmp;
 
         /* Update bus accounting */
         vio_cmo.min += size;
         vio_cmo.desired += viodev->cmo.desired;
     }
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
     return 0;
 }
 
 /**
  * vio_cmo_bus_remove - Handle CMO specific bus removal activities
  *
  * @viodev - Pointer to struct vio_dev for device
  *
  * Remove the device from the cmo device list.  The minimum entitlement
  * will be reserved for the device as long as it is in the system.  The
  * rest of the entitlement the device had been allocated will be returned
  * to the system.
  */
 static void vio_cmo_bus_remove(struct vio_dev *viodev)
 {
     struct vio_cmo_dev_entry *dev_ent;
     unsigned long flags;
     size_t tmp;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
     if (viodev->cmo.allocated) {
         dev_err(&viodev->dev, "%s: device had %lu bytes of IO "
                 "allocated after remove operation.\n",
                 __func__, viodev->cmo.allocated);
         BUG();
     }
 
     /*
      * Remove the device from the device list being maintained for
      * CMO enabled devices.
      */
     list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
         if (viodev == dev_ent->viodev) {
             list_del(&dev_ent->list);
             kfree(dev_ent);
             break;
         }
 
     /*
      * Devices may not require any entitlement and they do not need
      * to be processed.  Otherwise, return the device's entitlement
      * back to the pools.
      */
     if (viodev->cmo.entitled) {
         /*
          * This device has not yet left the OF tree, it's
          * minimum entitlement remains in vio_cmo.min and
          * vio_cmo.desired
          */
         vio_cmo.desired -= (viodev->cmo.desired - VIO_CMO_MIN_ENT);
 
         /*
          * Save min allocation for device in reserve as long
          * as it exists in OF tree as determined by later
          * balance operation
          */
         viodev->cmo.entitled -= VIO_CMO_MIN_ENT;
 
         /* Replenish spare from freed reserve pool */
         if (viodev->cmo.entitled && (vio_cmo.spare < VIO_CMO_MIN_ENT)) {
             tmp = min(viodev->cmo.entitled, (VIO_CMO_MIN_ENT -
                                              vio_cmo.spare));
             vio_cmo.spare += tmp;
             viodev->cmo.entitled -= tmp;
         }
 
         /* Remaining reserve goes to excess pool */
         vio_cmo.excess.size += viodev->cmo.entitled;
         vio_cmo.excess.free += viodev->cmo.entitled;
         vio_cmo.reserve.size -= viodev->cmo.entitled;
 
         /*
          * Until the device is removed it will keep a
          * minimum entitlement; this will guarantee that
          * a module unload/load will result in a success.
          */
         viodev->cmo.entitled = VIO_CMO_MIN_ENT;
         viodev->cmo.desired = VIO_CMO_MIN_ENT;
         atomic_set(&viodev->cmo.allocs_failed, 0);
     }
 
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
 }
 
 static void vio_cmo_set_dma_ops(struct vio_dev *viodev)
 {
     set_dma_ops(&viodev->dev, &vio_dma_mapping_ops);
 }
 
 /**
  * vio_cmo_bus_init - CMO entitlement initialization at bus init time
  *
  * Set up the reserve and excess entitlement pools based on available
  * system entitlement and the number of devices in the OF tree that
  * require entitlement in the reserve pool.
  */
 static void vio_cmo_bus_init(void)
 {
     struct hvcall_mpp_data mpp_data;
     int err;
 
     memset(&vio_cmo, 0, sizeof(struct vio_cmo));
     spin_lock_init(&vio_cmo.lock);
     INIT_LIST_HEAD(&vio_cmo.device_list);
     INIT_DELAYED_WORK(&vio_cmo.balance_q, vio_cmo_balance);
 
     /* Get current system entitlement */
     err = h_get_mpp(&mpp_data);
 
     /*
      * On failure, continue with entitlement set to 0, will panic()
      * later when spare is reserved.
      */
     if (err != H_SUCCESS) {
         printk(KERN_ERR "%s: unable to determine system IO "\
                "entitlement. (%d)\n", __func__, err);
         vio_cmo.entitled = 0;
     } else {
         vio_cmo.entitled = mpp_data.entitled_mem;
     }
 
     /* Set reservation and check against entitlement */
     vio_cmo.spare = VIO_CMO_MIN_ENT;
     vio_cmo.reserve.size = vio_cmo.spare;
     vio_cmo.reserve.size += (vio_cmo_num_OF_devs() *
                              VIO_CMO_MIN_ENT);
     if (vio_cmo.reserve.size > vio_cmo.entitled) {
         printk(KERN_ERR "%s: insufficient system entitlement\n",
                __func__);
         panic("%s: Insufficient system entitlement", __func__);
     }
 
     /* Set the remaining accounting variables */
     vio_cmo.excess.size = vio_cmo.entitled - vio_cmo.reserve.size;
     vio_cmo.excess.free = vio_cmo.excess.size;
     vio_cmo.min = vio_cmo.reserve.size;
     vio_cmo.desired = vio_cmo.reserve.size;
 }
 
 /* sysfs device functions and data structures for CMO */
 
 #define viodev_cmo_rd_attr(name)                                        \
 static ssize_t cmo_##name##_show(struct device *dev,                    \
                                         struct device_attribute *attr,  \
                                          char *buf)                     \
 {                                                                       \
     return sprintf(buf, "%lu\n", to_vio_dev(dev)->cmo.name);        \
 }
 
 static ssize_t cmo_allocs_failed_show(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     return sprintf(buf, "%d\n", atomic_read(&viodev->cmo.allocs_failed));
 }
 
 static ssize_t cmo_allocs_failed_store(struct device *dev,
         struct device_attribute *attr, const char *buf, size_t count)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     atomic_set(&viodev->cmo.allocs_failed, 0);
     return count;
 }
 
 static ssize_t cmo_desired_store(struct device *dev,
         struct device_attribute *attr, const char *buf, size_t count)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     size_t new_desired;
     int ret;
 
     ret = kstrtoul(buf, 10, &new_desired);
     if (ret)
         return ret;
 
     vio_cmo_set_dev_desired(viodev, new_desired);
     return count;
 }
 
 viodev_cmo_rd_attr(desired);
 viodev_cmo_rd_attr(entitled);
 viodev_cmo_rd_attr(allocated);
 
 static ssize_t name_show(struct device *, struct device_attribute *, char *);
 static ssize_t devspec_show(struct device *, struct device_attribute *, char *);
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
                  char *buf);
 
 static struct device_attribute dev_attr_name;
 static struct device_attribute dev_attr_devspec;
 static struct device_attribute dev_attr_modalias;
 
 static DEVICE_ATTR_RO(cmo_entitled);
 static DEVICE_ATTR_RO(cmo_allocated);
 static DEVICE_ATTR_RW(cmo_desired);
 static DEVICE_ATTR_RW(cmo_allocs_failed);
 
 static struct attribute *vio_cmo_dev_attrs[] = {
     &dev_attr_name.attr,
     &dev_attr_devspec.attr,
     &dev_attr_modalias.attr,
     &dev_attr_cmo_entitled.attr,
     &dev_attr_cmo_allocated.attr,
     &dev_attr_cmo_desired.attr,
     &dev_attr_cmo_allocs_failed.attr,
     NULL,
 };
 ATTRIBUTE_GROUPS(vio_cmo_dev);
 
 /* sysfs bus functions and data structures for CMO */
 
 #define viobus_cmo_rd_attr(name)                                        \
 static ssize_t cmo_bus_##name##_show(struct bus_type *bt, char *buf)    \
 {                                                                       \
     return sprintf(buf, "%lu\n", vio_cmo.name);                     \
 }                                                                       \
 static struct bus_attribute bus_attr_cmo_bus_##name =           \
     __ATTR(cmo_##name, S_IRUGO, cmo_bus_##name##_show, NULL)
 
 #define viobus_cmo_pool_rd_attr(name, var)                              \
 static ssize_t                                                          \
 cmo_##name##_##var##_show(struct bus_type *bt, char *buf)               \
 {                                                                       \
     return sprintf(buf, "%lu\n", vio_cmo.name.var);                 \
 }                                                                       \
 static BUS_ATTR_RO(cmo_##name##_##var)
 
 viobus_cmo_rd_attr(entitled);
 viobus_cmo_rd_attr(spare);
 viobus_cmo_rd_attr(min);
 viobus_cmo_rd_attr(desired);
 viobus_cmo_rd_attr(curr);
 viobus_cmo_pool_rd_attr(reserve, size);
 viobus_cmo_pool_rd_attr(excess, size);
 viobus_cmo_pool_rd_attr(excess, free);
 
 static ssize_t cmo_high_show(struct bus_type *bt, char *buf)
 {
     return sprintf(buf, "%lu\n", vio_cmo.high);
 }
 
 static ssize_t cmo_high_store(struct bus_type *bt, const char *buf,
                   size_t count)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&vio_cmo.lock, flags);
     vio_cmo.high = vio_cmo.curr;
     spin_unlock_irqrestore(&vio_cmo.lock, flags);
 
     return count;
 }
 static BUS_ATTR_RW(cmo_high);
 
 static struct attribute *vio_bus_attrs[] = {
     &bus_attr_cmo_bus_entitled.attr,
     &bus_attr_cmo_bus_spare.attr,
     &bus_attr_cmo_bus_min.attr,
     &bus_attr_cmo_bus_desired.attr,
     &bus_attr_cmo_bus_curr.attr,
     &bus_attr_cmo_high.attr,
     &bus_attr_cmo_reserve_size.attr,
     &bus_attr_cmo_excess_size.attr,
     &bus_attr_cmo_excess_free.attr,
     NULL,
 };
 ATTRIBUTE_GROUPS(vio_bus);
 
 static void __init vio_cmo_sysfs_init(void)
 {
     vio_bus_type.dev_groups = vio_cmo_dev_groups;
     vio_bus_type.bus_groups = vio_bus_groups;
 }
 #else /* CONFIG_PPC_SMLPAR */
 int vio_cmo_entitlement_update(size_t new_entitlement) { return 0; }
 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired) {}
 static int vio_cmo_bus_probe(struct vio_dev *viodev) { return 0; }
 static void vio_cmo_bus_remove(struct vio_dev *viodev) {}
 static void vio_cmo_set_dma_ops(struct vio_dev *viodev) {}
 static void vio_cmo_bus_init(void) {}
 static void __init vio_cmo_sysfs_init(void) { }
 #endif /* CONFIG_PPC_SMLPAR */
 EXPORT_SYMBOL(vio_cmo_entitlement_update);
 EXPORT_SYMBOL(vio_cmo_set_dev_desired);
 
 
 /*
  * Platform Facilities Option (PFO) support
  */
 
 /**
  * vio_h_cop_sync - Perform a synchronous PFO co-processor operation
  *
  * @vdev - Pointer to a struct vio_dev for device
  * @op - Pointer to a struct vio_pfo_op for the operation parameters
  *
  * Calls the hypervisor to synchronously perform the PFO operation
  * described in @op.  In the case of a busy response from the hypervisor,
  * the operation will be re-submitted indefinitely unless a non-zero timeout
  * is specified or an error occurs. The timeout places a limit on when to
  * stop re-submitting a operation, the total time can be exceeded if an
  * operation is in progress.
  *
  * If op->hcall_ret is not NULL, this will be set to the return from the
  * last h_cop_op call or it will be 0 if an error not involving the h_call
  * was encountered.
  *
  * Returns:
  *  0 on success,
  *  -EINVAL if the h_call fails due to an invalid parameter,
  *  -E2BIG if the h_call can not be performed synchronously,
  *  -EBUSY if a timeout is specified and has elapsed,
  *  -EACCES if the memory area for data/status has been rescinded, or
  *  -EPERM if a hardware fault has been indicated
  */
 int vio_h_cop_sync(struct vio_dev *vdev, struct vio_pfo_op *op)
 {
     struct device *dev = &vdev->dev;
     unsigned long deadline = 0;
     long hret = 0;
     int ret = 0;
 
     if (op->timeout)
         deadline = jiffies + msecs_to_jiffies(op->timeout);
 
     while (true) {
         hret = plpar_hcall_norets(H_COP, op->flags,
                 vdev->resource_id,
                 op->in, op->inlen, op->out,
                 op->outlen, op->csbcpb);
 
         if (hret == H_SUCCESS ||
             (hret != H_NOT_ENOUGH_RESOURCES &&
              hret != H_BUSY && hret != H_RESOURCE) ||
             (op->timeout && time_after(deadline, jiffies)))
             break;
 
         dev_dbg(dev, "%s: hcall ret(%ld), retrying.\n", __func__, hret);
     }
 
     switch (hret) {
     case H_SUCCESS:
         ret = 0;
         break;
     case H_OP_MODE:
     case H_TOO_BIG:
         ret = -E2BIG;
         break;
     case H_RESCINDED:
         ret = -EACCES;
         break;
     case H_HARDWARE:
         ret = -EPERM;
         break;
     case H_NOT_ENOUGH_RESOURCES:
     case H_RESOURCE:
     case H_BUSY:
         ret = -EBUSY;
         break;
     default:
         ret = -EINVAL;
         break;
     }
 
     if (ret)
         dev_dbg(dev, "%s: Sync h_cop_op failure (ret:%d) (hret:%ld)\n",
                 __func__, ret, hret);
 
     op->hcall_err = hret;
     return ret;
 }
 EXPORT_SYMBOL(vio_h_cop_sync);
 
 static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
 {
     const __be32 *dma_window;
     struct iommu_table *tbl;
     unsigned long offset, size;
 
     dma_window = of_get_property(dev->dev.of_node,
                   "ibm,my-dma-window", NULL);
     if (!dma_window)
         return NULL;
 
     tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
     if (tbl == NULL)
         return NULL;
 
     kref_init(&tbl->it_kref);
 
     of_parse_dma_window(dev->dev.of_node, dma_window,
                 &tbl->it_index, &offset, &size);
 
     /* TCE table size - measured in tce entries */
     tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
     tbl->it_size = size >> tbl->it_page_shift;
     /* offset for VIO should always be 0 */
     tbl->it_offset = offset >> tbl->it_page_shift;
     tbl->it_busno = 0;
     tbl->it_type = TCE_VB;
     tbl->it_blocksize = 16;
 
     if (firmware_has_feature(FW_FEATURE_LPAR))
         tbl->it_ops = &iommu_table_lpar_multi_ops;
     else
         tbl->it_ops = &iommu_table_pseries_ops;
 
     return iommu_init_table(tbl, -1, 0, 0);
 }
 
 /**
  * vio_match_device: - Tell if a VIO device has a matching
  *          VIO device id structure.
  * @ids:    array of VIO device id structures to search in
  * @dev:    the VIO device structure to match against
  *
  * Used by a driver to check whether a VIO device present in the
  * system is in its list of supported devices. Returns the matching
  * vio_device_id structure or NULL if there is no match.
  */
 static const struct vio_device_id *vio_match_device(
         const struct vio_device_id *ids, const struct vio_dev *dev)
 {
     while (ids->type[0] != '\0') {
         if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
             of_device_is_compatible(dev->dev.of_node,
                      ids->compat))
             return ids;
         ids++;
     }
     return NULL;
 }
 
 /*
  * Convert from struct device to struct vio_dev and pass to driver.
  * dev->driver has already been set by generic code because vio_bus_match
  * succeeded.
  */
 static int vio_bus_probe(struct device *dev)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct vio_driver *viodrv = to_vio_driver(dev->driver);
     const struct vio_device_id *id;
     int error = -ENODEV;
 
     if (!viodrv->probe)
         return error;
 
     id = vio_match_device(viodrv->id_table, viodev);
     if (id) {
         memset(&viodev->cmo, 0, sizeof(viodev->cmo));
         if (firmware_has_feature(FW_FEATURE_CMO)) {
             error = vio_cmo_bus_probe(viodev);
             if (error)
                 return error;
         }
         error = viodrv->probe(viodev, id);
         if (error && firmware_has_feature(FW_FEATURE_CMO))
             vio_cmo_bus_remove(viodev);
     }
 
     return error;
 }
 
 /* convert from struct device to struct vio_dev and pass to driver. */
 static void vio_bus_remove(struct device *dev)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct vio_driver *viodrv = to_vio_driver(dev->driver);
     struct device *devptr;
 
     /*
      * Hold a reference to the device after the remove function is called
      * to allow for CMO accounting cleanup for the device.
      */
     devptr = get_device(dev);
 
     if (viodrv->remove)
         viodrv->remove(viodev);
 
     if (firmware_has_feature(FW_FEATURE_CMO))
         vio_cmo_bus_remove(viodev);
 
     put_device(devptr);
 }
 
 static void vio_bus_shutdown(struct device *dev)
 {
     struct vio_dev *viodev = to_vio_dev(dev);
     struct vio_driver *viodrv;
 
     if (dev->driver) {
         viodrv = to_vio_driver(dev->driver);
         if (viodrv->shutdown)
             viodrv->shutdown(viodev);
         else if (kexec_in_progress)
             vio_bus_remove(dev);
     }
 }
 
 /**
  * vio_register_driver: - Register a new vio driver
  * @viodrv: The vio_driver structure to be registered.
  */
 int __vio_register_driver(struct vio_driver *viodrv, struct module *owner,
               const char *mod_name)
 {
     // vio_bus_type is only initialised for pseries
     if (!machine_is(pseries))
         return -ENODEV;
 
     pr_debug("%s: driver %s registering\n", __func__, viodrv->name);
 
     /* fill in 'struct driver' fields */
     viodrv->driver.name = viodrv->name;
     viodrv->driver.pm = viodrv->pm;
     viodrv->driver.bus = &vio_bus_type;
     viodrv->driver.owner = owner;
     viodrv->driver.mod_name = mod_name;
 
     return driver_register(&viodrv->driver);
 }
 EXPORT_SYMBOL(__vio_register_driver);
 
 /**
  * vio_unregister_driver - Remove registration of vio driver.
  * @viodrv: The vio_driver struct to be removed form registration
  */
 void vio_unregister_driver(struct vio_driver *viodrv)
 {
     driver_unregister(&viodrv->driver);
 }
 EXPORT_SYMBOL(vio_unregister_driver);
 
 /* vio_dev refcount hit 0 */
 static void vio_dev_release(struct device *dev)
 {
     struct iommu_table *tbl = get_iommu_table_base(dev);
 
     if (tbl)
         iommu_tce_table_put(tbl);
     of_node_put(dev->of_node);
     kfree(to_vio_dev(dev));
 }
 
 /**
  * vio_register_device_node: - Register a new vio device.
  * @of_node:    The OF node for this device.
  *
  * Creates and initializes a vio_dev structure from the data in
  * of_node and adds it to the list of virtual devices.
  * Returns a pointer to the created vio_dev or NULL if node has
  * NULL device_type or compatible fields.
  */
 struct vio_dev *vio_register_device_node(struct device_node *of_node)
 {
     struct vio_dev *viodev;
     struct device_node *parent_node;
     const __be32 *prop;
     enum vio_dev_family family;
 
     /*
      * Determine if this node is a under the /vdevice node or under the
      * /ibm,platform-facilities node.  This decides the device's family.
      */
     parent_node = of_get_parent(of_node);
     if (parent_node) {
         if (of_node_is_type(parent_node, "ibm,platform-facilities"))
             family = PFO;
         else if (of_node_is_type(parent_node, "vdevice"))
             family = VDEVICE;
         else {
             pr_warn("%s: parent(%pOF) of %pOFn not recognized.\n",
                     __func__,
                     parent_node,
                     of_node);
             of_node_put(parent_node);
             return NULL;
         }
         of_node_put(parent_node);
     } else {
         pr_warn("%s: could not determine the parent of node %pOFn.\n",
                 __func__, of_node);
         return NULL;
     }
 
     if (family == PFO) {
         if (of_get_property(of_node, "interrupt-controller", NULL)) {
             pr_debug("%s: Skipping the interrupt controller %pOFn.\n",
                     __func__, of_node);
             return NULL;
         }
     }
 
     /* allocate a vio_dev for this node */
     viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
     if (viodev == NULL) {
         pr_warn("%s: allocation failure for VIO device.\n", __func__);
         return NULL;
     }
 
     /* we need the 'device_type' property, in order to match with drivers */
     viodev->family = family;
     if (viodev->family == VDEVICE) {
         unsigned int unit_address;
 
         viodev->type = of_node_get_device_type(of_node);
         if (!viodev->type) {
             pr_warn("%s: node %pOFn is missing the 'device_type' "
                     "property.\n", __func__, of_node);
             goto out;
         }
 
         prop = of_get_property(of_node, "reg", NULL);
         if (prop == NULL) {
             pr_warn("%s: node %pOFn missing 'reg'\n",
                     __func__, of_node);
             goto out;
         }
         unit_address = of_read_number(prop, 1);
         dev_set_name(&viodev->dev, "%x", unit_address);
         viodev->irq = irq_of_parse_and_map(of_node, 0);
         viodev->unit_address = unit_address;
     } else {
         /* PFO devices need their resource_id for submitting COP_OPs
          * This is an optional field for devices, but is required when
          * performing synchronous ops */
         prop = of_get_property(of_node, "ibm,resource-id", NULL);
         if (prop != NULL)
             viodev->resource_id = of_read_number(prop, 1);
 
         dev_set_name(&viodev->dev, "%pOFn", of_node);
         viodev->type = dev_name(&viodev->dev);
         viodev->irq = 0;
     }
 
     viodev->name = of_node->name;
     viodev->dev.of_node = of_node_get(of_node);
 
     set_dev_node(&viodev->dev, of_node_to_nid(of_node));
 
     /* init generic 'struct device' fields: */
     viodev->dev.parent = &vio_bus_device.dev;
     viodev->dev.bus = &vio_bus_type;
     viodev->dev.release = vio_dev_release;
 
     if (of_get_property(viodev->dev.of_node, "ibm,my-dma-window", NULL)) {
         if (firmware_has_feature(FW_FEATURE_CMO))
             vio_cmo_set_dma_ops(viodev);
         else
             set_dma_ops(&viodev->dev, &dma_iommu_ops);
 
         set_iommu_table_base(&viodev->dev,
                      vio_build_iommu_table(viodev));
 
         /* needed to ensure proper operation of coherent allocations
          * later, in case driver doesn't set it explicitly */
         viodev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
         viodev->dev.dma_mask = &viodev->dev.coherent_dma_mask;
     }
 
     /* register with generic device framework */
     if (device_register(&viodev->dev)) {
         printk(KERN_ERR "%s: failed to register device %s\n",
                 __func__, dev_name(&viodev->dev));
         put_device(&viodev->dev);
         return NULL;
     }
 
     return viodev;
 
 out:    /* Use this exit point for any return prior to device_register */
     kfree(viodev);
 
     return NULL;
 }
 EXPORT_SYMBOL(vio_register_device_node);
 
 /*
  * vio_bus_scan_for_devices - Scan OF and register each child device
  * @root_name - OF node name for the root of the subtree to search.
  *      This must be non-NULL
  *
  * Starting from the root node provide, register the device node for
  * each child beneath the root.
  */
 static void __init vio_bus_scan_register_devices(char *root_name)
 {
     struct device_node *node_root, *node_child;
 
     if (!root_name)
         return;
 
     node_root = of_find_node_by_name(NULL, root_name);
     if (node_root) {
 
         /*
          * Create struct vio_devices for each virtual device in
          * the device tree. Drivers will associate with them later.
          */
         node_child = of_get_next_child(node_root, NULL);
         while (node_child) {
             vio_register_device_node(node_child);
             node_child = of_get_next_child(node_root, node_child);
         }
         of_node_put(node_root);
     }
 }
 
 /**
  * vio_bus_init: - Initialize the virtual IO bus
  */
 static int __init vio_bus_init(void)
 {
     int err;
 
     if (firmware_has_feature(FW_FEATURE_CMO))
         vio_cmo_sysfs_init();
 
     err = bus_register(&vio_bus_type);
     if (err) {
         printk(KERN_ERR "failed to register VIO bus\n");
         return err;
     }
 
     /*
      * The fake parent of all vio devices, just to give us
      * a nice directory
      */
     err = device_register(&vio_bus_device.dev);
     if (err) {
         printk(KERN_WARNING "%s: device_register returned %i\n",
                 __func__, err);
         return err;
     }
 
     if (firmware_has_feature(FW_FEATURE_CMO))
         vio_cmo_bus_init();
 
     return 0;
 }
 machine_postcore_initcall(pseries, vio_bus_init);
 
 static int __init vio_device_init(void)
 {
     vio_bus_scan_register_devices("vdevice");
     vio_bus_scan_register_devices("ibm,platform-facilities");
 
     return 0;
 }
 machine_device_initcall(pseries, vio_device_init);
 
 static ssize_t name_show(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
     return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
 }
 static DEVICE_ATTR_RO(name);
 
 static ssize_t devspec_show(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
     struct device_node *of_node = dev->of_node;
 
     return sprintf(buf, "%pOF\n", of_node);
 }
 static DEVICE_ATTR_RO(devspec);
 
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
                  char *buf)
 {
     const struct vio_dev *vio_dev = to_vio_dev(dev);
     struct device_node *dn;
     const char *cp;
 
     dn = dev->of_node;
     if (!dn) {
         strcpy(buf, "\n");
         return strlen(buf);
     }
     cp = of_get_property(dn, "compatible", NULL);
     if (!cp) {
         strcpy(buf, "\n");
         return strlen(buf);
     }
 
     return sprintf(buf, "vio:T%sS%s\n", vio_dev->type, cp);
 }
 static DEVICE_ATTR_RO(modalias);
 
 static struct attribute *vio_dev_attrs[] = {
     &dev_attr_name.attr,
     &dev_attr_devspec.attr,
     &dev_attr_modalias.attr,
     NULL,
 };
 ATTRIBUTE_GROUPS(vio_dev);
 
 void vio_unregister_device(struct vio_dev *viodev)
 {
     device_unregister(&viodev->dev);
     if (viodev->family == VDEVICE)
         irq_dispose_mapping(viodev->irq);
 }
 EXPORT_SYMBOL(vio_unregister_device);
 
 static int vio_bus_match(struct device *dev, struct device_driver *drv)
 {
     const struct vio_dev *vio_dev = to_vio_dev(dev);
     struct vio_driver *vio_drv = to_vio_driver(drv);
     const struct vio_device_id *ids = vio_drv->id_table;
 
     return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
 }
 
 static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
 {
     const struct vio_dev *vio_dev = to_vio_dev(dev);
     struct device_node *dn;
     const char *cp;
 
     dn = dev->of_node;
     if (!dn)
         return -ENODEV;
     cp = of_get_property(dn, "compatible", NULL);
     if (!cp)
         return -ENODEV;
 
     add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
     return 0;
 }
 
 struct bus_type vio_bus_type = {
     .name = "vio",
     .dev_groups = vio_dev_groups,
     .uevent = vio_hotplug,
     .match = vio_bus_match,
     .probe = vio_bus_probe,
     .remove = vio_bus_remove,
     .shutdown = vio_bus_shutdown,
 };
 
 /**
  * vio_get_attribute: - get attribute for virtual device
  * @vdev:   The vio device to get property.
  * @which:  The property/attribute to be extracted.
  * @length: Pointer to length of returned data size (unused if NULL).
  *
  * Calls prom.c's of_get_property() to return the value of the
  * attribute specified by @which
 */
 const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
 {
     return of_get_property(vdev->dev.of_node, which, length);
 }
 EXPORT_SYMBOL(vio_get_attribute);
 
 /* vio_find_name() - internal because only vio.c knows how we formatted the
  * kobject name
  */
 static struct vio_dev *vio_find_name(const char *name)
 {
     struct device *found;
 
     found = bus_find_device_by_name(&vio_bus_type, NULL, name);
     if (!found)
         return NULL;
 
     return to_vio_dev(found);
 }
 
 /**
  * vio_find_node - find an already-registered vio_dev
  * @vnode: device_node of the virtual device we're looking for
  *
  * Takes a reference to the embedded struct device which needs to be dropped
  * after use.
  */
 struct vio_dev *vio_find_node(struct device_node *vnode)
 {
     char kobj_name[20];
     struct device_node *vnode_parent;
 
     vnode_parent = of_get_parent(vnode);
     if (!vnode_parent)
         return NULL;
 
     /* construct the kobject name from the device node */
     if (of_node_is_type(vnode_parent, "vdevice")) {
         const __be32 *prop;
         
         prop = of_get_property(vnode, "reg", NULL);
         if (!prop)
             goto out;
         snprintf(kobj_name, sizeof(kobj_name), "%x",
              (uint32_t)of_read_number(prop, 1));
     } else if (of_node_is_type(vnode_parent, "ibm,platform-facilities"))
         snprintf(kobj_name, sizeof(kobj_name), "%pOFn", vnode);
     else
         goto out;
 
     of_node_put(vnode_parent);
     return vio_find_name(kobj_name);
 out:
     of_node_put(vnode_parent);
     return NULL;
 }
 EXPORT_SYMBOL(vio_find_node);
 
 int vio_enable_interrupts(struct vio_dev *dev)
 {
     int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
     if (rc != H_SUCCESS)
         printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
     return rc;
 }
 EXPORT_SYMBOL(vio_enable_interrupts);
 
 int vio_disable_interrupts(struct vio_dev *dev)
 {
     int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
     if (rc != H_SUCCESS)
         printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
     return rc;
 }
 EXPORT_SYMBOL(vio_disable_interrupts);
 
 static int __init vio_init(void)
 {
     dma_debug_add_bus(&vio_bus_type);
     return 0;
 }
 machine_fs_initcall(pseries, vio_init);

This page was automatically generated by the 2.1.0 LXR engine. The LXR team