drm/exynos/exynos_drm_gem.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /* exynos_drm_gem.c
0003  *
0004  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
0005  * Author: Inki Dae <inki.dae@samsung.com>
0006  */
0007
0008
0009 #include <linux/dma-buf.h>
0010 #include <linux/pfn_t.h>
0011 #include <linux/shmem_fs.h>
0012 #include <linux/module.h>
0013
0014 #include <drm/drm_prime.h>
0015 #include <drm/drm_vma_manager.h>
0016 #include <drm/exynos_drm.h>
0017
0018 #include "exynos_drm_drv.h"
0019 #include "exynos_drm_gem.h"
0020
0021 MODULE_IMPORT_NS(DMA_BUF);
0022
0023 static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
0024
0025 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
0026 {
0027     struct drm_device *dev = exynos_gem->base.dev;
0028     unsigned long attr = 0;
0029
0030     if (exynos_gem->dma_addr) {
0031         DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
0032         return 0;
0033     }
0034
0035     /*
0036      * if EXYNOS_BO_CONTIG, fully physically contiguous memory
0037      * region will be allocated else physically contiguous
0038      * as possible.
0039      */
0040     if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
0041         attr |= DMA_ATTR_FORCE_CONTIGUOUS;
0042
0043     /*
0044      * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
0045      * else cachable mapping.
0046      */
0047     if (exynos_gem->flags & EXYNOS_BO_WC ||
0048             !(exynos_gem->flags & EXYNOS_BO_CACHABLE))
0049         attr |= DMA_ATTR_WRITE_COMBINE;
0050
0051     /* FBDev emulation requires kernel mapping */
0052     if (!kvmap)
0053         attr |= DMA_ATTR_NO_KERNEL_MAPPING;
0054
0055     exynos_gem->dma_attrs = attr;
0056     exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
0057                          &exynos_gem->dma_addr, GFP_KERNEL,
0058                          exynos_gem->dma_attrs);
0059     if (!exynos_gem->cookie) {
0060         DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
0061         return -ENOMEM;
0062     }
0063
0064     if (kvmap)
0065         exynos_gem->kvaddr = exynos_gem->cookie;
0066
0067     DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
0068             (unsigned long)exynos_gem->dma_addr, exynos_gem->size);
0069     return 0;
0070 }
0071
0072 static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
0073 {
0074     struct drm_device *dev = exynos_gem->base.dev;
0075
0076     if (!exynos_gem->dma_addr) {
0077         DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
0078         return;
0079     }
0080
0081     DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
0082             (unsigned long)exynos_gem->dma_addr, exynos_gem->size);
0083
0084     dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
0085             (dma_addr_t)exynos_gem->dma_addr,
0086             exynos_gem->dma_attrs);
0087 }
0088
0089 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
0090                     struct drm_file *file_priv,
0091                     unsigned int *handle)
0092 {
0093     int ret;
0094
0095     /*
0096      * allocate a id of idr table where the obj is registered
0097      * and handle has the id what user can see.
0098      */
0099     ret = drm_gem_handle_create(file_priv, obj, handle);
0100     if (ret)
0101         return ret;
0102
0103     DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
0104
0105     /* drop reference from allocate - handle holds it now. */
0106     drm_gem_object_put(obj);
0107
0108     return 0;
0109 }
0110
0111 void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
0112 {
0113     struct drm_gem_object *obj = &exynos_gem->base;
0114
0115     DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
0116               obj->handle_count);
0117
0118     /*
0119      * do not release memory region from exporter.
0120      *
0121      * the region will be released by exporter
0122      * once dmabuf's refcount becomes 0.
0123      */
0124     if (obj->import_attach)
0125         drm_prime_gem_destroy(obj, exynos_gem->sgt);
0126     else
0127         exynos_drm_free_buf(exynos_gem);
0128
0129     /* release file pointer to gem object. */
0130     drm_gem_object_release(obj);
0131
0132     kfree(exynos_gem);
0133 }
0134
0135 static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
0136     .open = drm_gem_vm_open,
0137     .close = drm_gem_vm_close,
0138 };
0139
0140 static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
0141     .free = exynos_drm_gem_free_object,
0142     .get_sg_table = exynos_drm_gem_prime_get_sg_table,
0143     .mmap = exynos_drm_gem_mmap,
0144     .vm_ops = &exynos_drm_gem_vm_ops,
0145 };
0146
0147 static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
0148                           unsigned long size)
0149 {
0150     struct exynos_drm_gem *exynos_gem;
0151     struct drm_gem_object *obj;
0152     int ret;
0153
0154     exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
0155     if (!exynos_gem)
0156         return ERR_PTR(-ENOMEM);
0157
0158     exynos_gem->size = size;
0159     obj = &exynos_gem->base;
0160
0161     obj->funcs = &exynos_drm_gem_object_funcs;
0162
0163     ret = drm_gem_object_init(dev, obj, size);
0164     if (ret < 0) {
0165         DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
0166         kfree(exynos_gem);
0167         return ERR_PTR(ret);
0168     }
0169
0170     ret = drm_gem_create_mmap_offset(obj);
0171     if (ret < 0) {
0172         drm_gem_object_release(obj);
0173         kfree(exynos_gem);
0174         return ERR_PTR(ret);
0175     }
0176
0177     DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %pK\n", obj->filp);
0178
0179     return exynos_gem;
0180 }
0181
0182 struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
0183                          unsigned int flags,
0184                          unsigned long size,
0185                          bool kvmap)
0186 {
0187     struct exynos_drm_gem *exynos_gem;
0188     int ret;
0189
0190     if (flags & ~(EXYNOS_BO_MASK)) {
0191         DRM_DEV_ERROR(dev->dev,
0192                   "invalid GEM buffer flags: %u\n", flags);
0193         return ERR_PTR(-EINVAL);
0194     }
0195
0196     if (!size) {
0197         DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
0198         return ERR_PTR(-EINVAL);
0199     }
0200
0201     size = roundup(size, PAGE_SIZE);
0202
0203     exynos_gem = exynos_drm_gem_init(dev, size);
0204     if (IS_ERR(exynos_gem))
0205         return exynos_gem;
0206
0207     if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
0208         /*
0209          * when no IOMMU is available, all allocated buffers are
0210          * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
0211          */
0212         flags &= ~EXYNOS_BO_NONCONTIG;
0213         DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
0214     }
0215
0216     /* set memory type and cache attribute from user side. */
0217     exynos_gem->flags = flags;
0218
0219     ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
0220     if (ret < 0) {
0221         drm_gem_object_release(&exynos_gem->base);
0222         kfree(exynos_gem);
0223         return ERR_PTR(ret);
0224     }
0225
0226     return exynos_gem;
0227 }
0228
0229 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
0230                 struct drm_file *file_priv)
0231 {
0232     struct drm_exynos_gem_create *args = data;
0233     struct exynos_drm_gem *exynos_gem;
0234     int ret;
0235
0236     exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
0237     if (IS_ERR(exynos_gem))
0238         return PTR_ERR(exynos_gem);
0239
0240     ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
0241                        &args->handle);
0242     if (ret) {
0243         exynos_drm_gem_destroy(exynos_gem);
0244         return ret;
0245     }
0246
0247     return 0;
0248 }
0249
0250 int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
0251                  struct drm_file *file_priv)
0252 {
0253     struct drm_exynos_gem_map *args = data;
0254
0255     return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
0256                        &args->offset);
0257 }
0258
0259 struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
0260                       unsigned int gem_handle)
0261 {
0262     struct drm_gem_object *obj;
0263
0264     obj = drm_gem_object_lookup(filp, gem_handle);
0265     if (!obj)
0266         return NULL;
0267     return to_exynos_gem(obj);
0268 }
0269
0270 static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
0271                       struct vm_area_struct *vma)
0272 {
0273     struct drm_device *drm_dev = exynos_gem->base.dev;
0274     unsigned long vm_size;
0275     int ret;
0276
0277     vma->vm_flags &= ~VM_PFNMAP;
0278     vma->vm_pgoff = 0;
0279
0280     vm_size = vma->vm_end - vma->vm_start;
0281
0282     /* check if user-requested size is valid. */
0283     if (vm_size > exynos_gem->size)
0284         return -EINVAL;
0285
0286     ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
0287                  exynos_gem->dma_addr, exynos_gem->size,
0288                  exynos_gem->dma_attrs);
0289     if (ret < 0) {
0290         DRM_ERROR("failed to mmap.\n");
0291         return ret;
0292     }
0293
0294     return 0;
0295 }
0296
0297 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
0298                       struct drm_file *file_priv)
0299 {
0300     struct exynos_drm_gem *exynos_gem;
0301     struct drm_exynos_gem_info *args = data;
0302     struct drm_gem_object *obj;
0303
0304     obj = drm_gem_object_lookup(file_priv, args->handle);
0305     if (!obj) {
0306         DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
0307         return -EINVAL;
0308     }
0309
0310     exynos_gem = to_exynos_gem(obj);
0311
0312     args->flags = exynos_gem->flags;
0313     args->size = exynos_gem->size;
0314
0315     drm_gem_object_put(obj);
0316
0317     return 0;
0318 }
0319
0320 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
0321 {
0322     exynos_drm_gem_destroy(to_exynos_gem(obj));
0323 }
0324
0325 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
0326                    struct drm_device *dev,
0327                    struct drm_mode_create_dumb *args)
0328 {
0329     struct exynos_drm_gem *exynos_gem;
0330     unsigned int flags;
0331     int ret;
0332
0333     /*
0334      * allocate memory to be used for framebuffer.
0335      * - this callback would be called by user application
0336      *  with DRM_IOCTL_MODE_CREATE_DUMB command.
0337      */
0338
0339     args->pitch = args->width * ((args->bpp + 7) / 8);
0340     args->size = args->pitch * args->height;
0341
0342     if (is_drm_iommu_supported(dev))
0343         flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
0344     else
0345         flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
0346
0347     exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
0348     if (IS_ERR(exynos_gem)) {
0349         dev_warn(dev->dev, "FB allocation failed.\n");
0350         return PTR_ERR(exynos_gem);
0351     }
0352
0353     ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
0354                        &args->handle);
0355     if (ret) {
0356         exynos_drm_gem_destroy(exynos_gem);
0357         return ret;
0358     }
0359
0360     return 0;
0361 }
0362
0363 static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
0364 {
0365     struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
0366     int ret;
0367
0368     if (obj->import_attach)
0369         return dma_buf_mmap(obj->dma_buf, vma, 0);
0370
0371     vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
0372
0373     DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
0374               exynos_gem->flags);
0375
0376     /* non-cachable as default. */
0377     if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
0378         vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
0379     else if (exynos_gem->flags & EXYNOS_BO_WC)
0380         vma->vm_page_prot =
0381             pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
0382     else
0383         vma->vm_page_prot =
0384             pgprot_noncached(vm_get_page_prot(vma->vm_flags));
0385
0386     ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
0387     if (ret)
0388         goto err_close_vm;
0389
0390     return ret;
0391
0392 err_close_vm:
0393     drm_gem_vm_close(vma);
0394
0395     return ret;
0396 }
0397
0398 /* low-level interface prime helpers */
0399 struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
0400                         struct dma_buf *dma_buf)
0401 {
0402     return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
0403 }
0404
0405 struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
0406 {
0407     struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
0408     struct drm_device *drm_dev = obj->dev;
0409     struct sg_table *sgt;
0410     int ret;
0411
0412     sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
0413     if (!sgt)
0414         return ERR_PTR(-ENOMEM);
0415
0416     ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
0417                     exynos_gem->dma_addr, exynos_gem->size,
0418                     exynos_gem->dma_attrs);
0419     if (ret) {
0420         DRM_ERROR("failed to get sgtable, %d\n", ret);
0421         kfree(sgt);
0422         return ERR_PTR(ret);
0423     }
0424
0425     return sgt;
0426 }
0427
0428 struct drm_gem_object *
0429 exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
0430                      struct dma_buf_attachment *attach,
0431                      struct sg_table *sgt)
0432 {
0433     struct exynos_drm_gem *exynos_gem;
0434
0435     /* check if the entries in the sg_table are contiguous */
0436     if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
0437         DRM_ERROR("buffer chunks must be mapped contiguously");
0438         return ERR_PTR(-EINVAL);
0439     }
0440
0441     exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
0442     if (IS_ERR(exynos_gem))
0443         return ERR_CAST(exynos_gem);
0444
0445     /*
0446      * Buffer has been mapped as contiguous into DMA address space,
0447      * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
0448      * We assume a simplified logic below:
0449      */
0450     if (is_drm_iommu_supported(dev))
0451         exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
0452     else
0453         exynos_gem->flags |= EXYNOS_BO_CONTIG;
0454
0455     exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
0456     exynos_gem->sgt = sgt;
0457     return &exynos_gem->base;
0458 }