| /* |
| * drm gem CMA (contiguous memory allocator) helper functions |
| * |
| * Copyright (C) 2012 Sascha Hauer, Pengutronix |
| * |
| * Based on Samsung Exynos code |
| * |
| * Copyright (c) 2011 Samsung Electronics Co., Ltd. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/mutex.h> |
| #include <linux/export.h> |
| #include <linux/dma-buf.h> |
| #include <linux/dma-mapping.h> |
| |
| #include <drm/drmP.h> |
| #include <drm/drm.h> |
| #include <drm/drm_gem_cma_helper.h> |
| #include <drm/drm_vma_manager.h> |
| |
| /** |
| * DOC: cma helpers |
| * |
| * The Contiguous Memory Allocator reserves a pool of memory at early boot |
| * that is used to service requests for large blocks of contiguous memory. |
| * |
| * The DRM GEM/CMA helpers use this allocator as a means to provide buffer |
| * objects that are physically contiguous in memory. This is useful for |
| * display drivers that are unable to map scattered buffers via an IOMMU. |
| */ |
| |
| /** |
| * __drm_gem_cma_create - Create a GEM CMA object without allocating memory |
| * @drm: DRM device |
| * @size: size of the object to allocate |
| * |
| * This function creates and initializes a GEM CMA object of the given size, |
| * but doesn't allocate any memory to back the object. |
| * |
| * Returns: |
| * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative |
| * error code on failure. |
| */ |
| static struct drm_gem_cma_object * |
| __drm_gem_cma_create(struct drm_device *drm, size_t size) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| struct drm_gem_object *gem_obj; |
| int ret; |
| |
| if (drm->driver->gem_create_object) |
| gem_obj = drm->driver->gem_create_object(drm, size); |
| else |
| gem_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); |
| if (!gem_obj) |
| return ERR_PTR(-ENOMEM); |
| cma_obj = container_of(gem_obj, struct drm_gem_cma_object, base); |
| |
| ret = drm_gem_object_init(drm, gem_obj, size); |
| if (ret) |
| goto error; |
| |
| ret = drm_gem_create_mmap_offset(gem_obj); |
| if (ret) { |
| drm_gem_object_release(gem_obj); |
| goto error; |
| } |
| |
| return cma_obj; |
| |
| error: |
| kfree(cma_obj); |
| return ERR_PTR(ret); |
| } |
| |
| /** |
| * drm_gem_cma_create - allocate an object with the given size |
| * @drm: DRM device |
| * @size: size of the object to allocate |
| * |
| * This function creates a CMA GEM object and allocates a contiguous chunk of |
| * memory as backing store. The backing memory has the writecombine attribute |
| * set. |
| * |
| * Returns: |
| * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative |
| * error code on failure. |
| */ |
| struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, |
| size_t size) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| int ret; |
| |
| size = round_up(size, PAGE_SIZE); |
| |
| cma_obj = __drm_gem_cma_create(drm, size); |
| if (IS_ERR(cma_obj)) |
| return cma_obj; |
| |
| cma_obj->vaddr = dma_alloc_wc(drm->dev, size, &cma_obj->paddr, |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!cma_obj->vaddr) { |
| dev_err(drm->dev, "failed to allocate buffer with size %zu\n", |
| size); |
| ret = -ENOMEM; |
| goto error; |
| } |
| |
| return cma_obj; |
| |
| error: |
| drm->driver->gem_free_object(&cma_obj->base); |
| return ERR_PTR(ret); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_create); |
| |
| /** |
| * drm_gem_cma_create_with_handle - allocate an object with the given size and |
| * return a GEM handle to it |
| * @file_priv: DRM file-private structure to register the handle for |
| * @drm: DRM device |
| * @size: size of the object to allocate |
| * @handle: return location for the GEM handle |
| * |
| * This function creates a CMA GEM object, allocating a physically contiguous |
| * chunk of memory as backing store. The GEM object is then added to the list |
| * of object associated with the given file and a handle to it is returned. |
| * |
| * Returns: |
| * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative |
| * error code on failure. |
| */ |
| static struct drm_gem_cma_object * |
| drm_gem_cma_create_with_handle(struct drm_file *file_priv, |
| struct drm_device *drm, size_t size, |
| uint32_t *handle) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| struct drm_gem_object *gem_obj; |
| int ret; |
| |
| cma_obj = drm_gem_cma_create(drm, size); |
| if (IS_ERR(cma_obj)) |
| return cma_obj; |
| |
| gem_obj = &cma_obj->base; |
| |
| /* |
| * allocate a id of idr table where the obj is registered |
| * and handle has the id what user can see. |
| */ |
| ret = drm_gem_handle_create(file_priv, gem_obj, handle); |
| if (ret) |
| goto err_handle_create; |
| |
| /* drop reference from allocate - handle holds it now. */ |
| drm_gem_object_unreference_unlocked(gem_obj); |
| |
| return cma_obj; |
| |
| err_handle_create: |
| drm->driver->gem_free_object(gem_obj); |
| |
| return ERR_PTR(ret); |
| } |
| |
| /** |
| * drm_gem_cma_free_object - free resources associated with a CMA GEM object |
| * @gem_obj: GEM object to free |
| * |
| * This function frees the backing memory of the CMA GEM object, cleans up the |
| * GEM object state and frees the memory used to store the object itself. |
| * Drivers using the CMA helpers should set this as their DRM driver's |
| * ->gem_free_object() callback. |
| */ |
| void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| |
| cma_obj = to_drm_gem_cma_obj(gem_obj); |
| |
| if (cma_obj->vaddr) { |
| dma_free_wc(gem_obj->dev->dev, cma_obj->base.size, |
| cma_obj->vaddr, cma_obj->paddr); |
| } else if (gem_obj->import_attach) { |
| drm_prime_gem_destroy(gem_obj, cma_obj->sgt); |
| } |
| |
| drm_gem_object_release(gem_obj); |
| |
| kfree(cma_obj); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); |
| |
| /** |
| * drm_gem_cma_dumb_create_internal - create a dumb buffer object |
| * @file_priv: DRM file-private structure to create the dumb buffer for |
| * @drm: DRM device |
| * @args: IOCTL data |
| * |
| * This aligns the pitch and size arguments to the minimum required. This is |
| * an internal helper that can be wrapped by a driver to account for hardware |
| * with more specific alignment requirements. It should not be used directly |
| * as the ->dumb_create() callback in a DRM driver. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_cma_dumb_create_internal(struct drm_file *file_priv, |
| struct drm_device *drm, |
| struct drm_mode_create_dumb *args) |
| { |
| unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); |
| struct drm_gem_cma_object *cma_obj; |
| |
| if (args->pitch < min_pitch) |
| args->pitch = min_pitch; |
| |
| if (args->size < args->pitch * args->height) |
| args->size = args->pitch * args->height; |
| |
| cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size, |
| &args->handle); |
| return PTR_ERR_OR_ZERO(cma_obj); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create_internal); |
| |
| /** |
| * drm_gem_cma_dumb_create - create a dumb buffer object |
| * @file_priv: DRM file-private structure to create the dumb buffer for |
| * @drm: DRM device |
| * @args: IOCTL data |
| * |
| * This function computes the pitch of the dumb buffer and rounds it up to an |
| * integer number of bytes per pixel. Drivers for hardware that doesn't have |
| * any additional restrictions on the pitch can directly use this function as |
| * their ->dumb_create() callback. |
| * |
| * For hardware with additional restrictions, drivers can adjust the fields |
| * set up by userspace and pass the IOCTL data along to the |
| * drm_gem_cma_dumb_create_internal() function. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_cma_dumb_create(struct drm_file *file_priv, |
| struct drm_device *drm, |
| struct drm_mode_create_dumb *args) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| |
| args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); |
| args->size = args->pitch * args->height; |
| |
| cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size, |
| &args->handle); |
| return PTR_ERR_OR_ZERO(cma_obj); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); |
| |
| /** |
| * drm_gem_cma_dumb_map_offset - return the fake mmap offset for a CMA GEM |
| * object |
| * @file_priv: DRM file-private structure containing the GEM object |
| * @drm: DRM device |
| * @handle: GEM object handle |
| * @offset: return location for the fake mmap offset |
| * |
| * This function look up an object by its handle and returns the fake mmap |
| * offset associated with it. Drivers using the CMA helpers should set this |
| * as their DRM driver's ->dumb_map_offset() callback. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, |
| struct drm_device *drm, u32 handle, |
| u64 *offset) |
| { |
| struct drm_gem_object *gem_obj; |
| |
| gem_obj = drm_gem_object_lookup(drm, file_priv, handle); |
| if (!gem_obj) { |
| dev_err(drm->dev, "failed to lookup GEM object\n"); |
| return -EINVAL; |
| } |
| |
| *offset = drm_vma_node_offset_addr(&gem_obj->vma_node); |
| |
| drm_gem_object_unreference_unlocked(gem_obj); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset); |
| |
| const struct vm_operations_struct drm_gem_cma_vm_ops = { |
| .open = drm_gem_vm_open, |
| .close = drm_gem_vm_close, |
| }; |
| EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops); |
| |
| static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj, |
| struct vm_area_struct *vma) |
| { |
| int ret; |
| |
| /* |
| * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the |
| * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map |
| * the whole buffer. |
| */ |
| vma->vm_flags &= ~VM_PFNMAP; |
| vma->vm_pgoff = 0; |
| |
| ret = dma_mmap_wc(cma_obj->base.dev->dev, vma, cma_obj->vaddr, |
| cma_obj->paddr, vma->vm_end - vma->vm_start); |
| if (ret) |
| drm_gem_vm_close(vma); |
| |
| return ret; |
| } |
| |
| /** |
| * drm_gem_cma_mmap - memory-map a CMA GEM object |
| * @filp: file object |
| * @vma: VMA for the area to be mapped |
| * |
| * This function implements an augmented version of the GEM DRM file mmap |
| * operation for CMA objects: In addition to the usual GEM VMA setup it |
| * immediately faults in the entire object instead of using on-demaind |
| * faulting. Drivers which employ the CMA helpers should use this function |
| * as their ->mmap() handler in the DRM device file's file_operations |
| * structure. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| struct drm_gem_object *gem_obj; |
| int ret; |
| |
| ret = drm_gem_mmap(filp, vma); |
| if (ret) |
| return ret; |
| |
| gem_obj = vma->vm_private_data; |
| cma_obj = to_drm_gem_cma_obj(gem_obj); |
| |
| return drm_gem_cma_mmap_obj(cma_obj, vma); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); |
| |
| #ifdef CONFIG_DEBUG_FS |
| /** |
| * drm_gem_cma_describe - describe a CMA GEM object for debugfs |
| * @cma_obj: CMA GEM object |
| * @m: debugfs file handle |
| * |
| * This function can be used to dump a human-readable representation of the |
| * CMA GEM object into a synthetic file. |
| */ |
| void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, |
| struct seq_file *m) |
| { |
| struct drm_gem_object *obj = &cma_obj->base; |
| uint64_t off; |
| |
| off = drm_vma_node_start(&obj->vma_node); |
| |
| seq_printf(m, "%2d (%2d) %08llx %pad %p %zu", |
| obj->name, obj->refcount.refcount.counter, |
| off, &cma_obj->paddr, cma_obj->vaddr, obj->size); |
| |
| seq_printf(m, "\n"); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_describe); |
| #endif |
| |
| /** |
| * drm_gem_cma_prime_get_sg_table - provide a scatter/gather table of pinned |
| * pages for a CMA GEM object |
| * @obj: GEM object |
| * |
| * This function exports a scatter/gather table suitable for PRIME usage by |
| * calling the standard DMA mapping API. Drivers using the CMA helpers should |
| * set this as their DRM driver's ->gem_prime_get_sg_table() callback. |
| * |
| * Returns: |
| * A pointer to the scatter/gather table of pinned pages or NULL on failure. |
| */ |
| struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj) |
| { |
| struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); |
| struct sg_table *sgt; |
| int ret; |
| |
| sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); |
| if (!sgt) |
| return NULL; |
| |
| ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr, |
| cma_obj->paddr, obj->size); |
| if (ret < 0) |
| goto out; |
| |
| return sgt; |
| |
| out: |
| kfree(sgt); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table); |
| |
| /** |
| * drm_gem_cma_prime_import_sg_table - produce a CMA GEM object from another |
| * driver's scatter/gather table of pinned pages |
| * @dev: device to import into |
| * @attach: DMA-BUF attachment |
| * @sgt: scatter/gather table of pinned pages |
| * |
| * This function imports a scatter/gather table exported via DMA-BUF by |
| * another driver. Imported buffers must be physically contiguous in memory |
| * (i.e. the scatter/gather table must contain a single entry). Drivers that |
| * use the CMA helpers should set this as their DRM driver's |
| * ->gem_prime_import_sg_table() callback. |
| * |
| * Returns: |
| * A pointer to a newly created GEM object or an ERR_PTR-encoded negative |
| * error code on failure. |
| */ |
| struct drm_gem_object * |
| drm_gem_cma_prime_import_sg_table(struct drm_device *dev, |
| struct dma_buf_attachment *attach, |
| struct sg_table *sgt) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| |
| if (sgt->nents != 1) |
| return ERR_PTR(-EINVAL); |
| |
| /* Create a CMA GEM buffer. */ |
| cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size); |
| if (IS_ERR(cma_obj)) |
| return ERR_CAST(cma_obj); |
| |
| cma_obj->paddr = sg_dma_address(sgt->sgl); |
| cma_obj->sgt = sgt; |
| |
| DRM_DEBUG_PRIME("dma_addr = %pad, size = %zu\n", &cma_obj->paddr, attach->dmabuf->size); |
| |
| return &cma_obj->base; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); |
| |
| /** |
| * drm_gem_cma_prime_mmap - memory-map an exported CMA GEM object |
| * @obj: GEM object |
| * @vma: VMA for the area to be mapped |
| * |
| * This function maps a buffer imported via DRM PRIME into a userspace |
| * process's address space. Drivers that use the CMA helpers should set this |
| * as their DRM driver's ->gem_prime_mmap() callback. |
| * |
| * Returns: |
| * 0 on success or a negative error code on failure. |
| */ |
| int drm_gem_cma_prime_mmap(struct drm_gem_object *obj, |
| struct vm_area_struct *vma) |
| { |
| struct drm_gem_cma_object *cma_obj; |
| int ret; |
| |
| ret = drm_gem_mmap_obj(obj, obj->size, vma); |
| if (ret < 0) |
| return ret; |
| |
| cma_obj = to_drm_gem_cma_obj(obj); |
| return drm_gem_cma_mmap_obj(cma_obj, vma); |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap); |
| |
| /** |
| * drm_gem_cma_prime_vmap - map a CMA GEM object into the kernel's virtual |
| * address space |
| * @obj: GEM object |
| * |
| * This function maps a buffer exported via DRM PRIME into the kernel's |
| * virtual address space. Since the CMA buffers are already mapped into the |
| * kernel virtual address space this simply returns the cached virtual |
| * address. Drivers using the CMA helpers should set this as their DRM |
| * driver's ->gem_prime_vmap() callback. |
| * |
| * Returns: |
| * The kernel virtual address of the CMA GEM object's backing store. |
| */ |
| void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj) |
| { |
| struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); |
| |
| return cma_obj->vaddr; |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap); |
| |
| /** |
| * drm_gem_cma_prime_vunmap - unmap a CMA GEM object from the kernel's virtual |
| * address space |
| * @obj: GEM object |
| * @vaddr: kernel virtual address where the CMA GEM object was mapped |
| * |
| * This function removes a buffer exported via DRM PRIME from the kernel's |
| * virtual address space. This is a no-op because CMA buffers cannot be |
| * unmapped from kernel space. Drivers using the CMA helpers should set this |
| * as their DRM driver's ->gem_prime_vunmap() callback. |
| */ |
| void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr) |
| { |
| /* Nothing to do */ |
| } |
| EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap); |