diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gem_vram_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem_vram_helper.c | 641 |
1 files changed, 641 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c new file mode 100644 index 000000000000..4de782ca26b2 --- /dev/null +++ b/drivers/gpu/drm/drm_gem_vram_helper.c @@ -0,0 +1,641 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <drm/drm_gem_vram_helper.h> +#include <drm/drm_device.h> +#include <drm/drm_mode.h> +#include <drm/drm_prime.h> +#include <drm/drm_vram_mm_helper.h> +#include <drm/ttm/ttm_page_alloc.h> + +/** + * DOC: overview + * + * This library provides a GEM buffer object that is backed by video RAM + * (VRAM). It can be used for framebuffer devices with dedicated memory. + */ + +/* + * Buffer-objects helpers + */ + +static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo) +{ + /* We got here via ttm_bo_put(), which means that the + * TTM buffer object in 'bo' has already been cleaned + * up; only release the GEM object. + */ + drm_gem_object_release(&gbo->gem); +} + +static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo) +{ + drm_gem_vram_cleanup(gbo); + kfree(gbo); +} + +static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo); + + drm_gem_vram_destroy(gbo); +} + +static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, + unsigned long pl_flag) +{ + unsigned int i; + unsigned int c = 0; + + gbo->placement.placement = gbo->placements; + gbo->placement.busy_placement = gbo->placements; + + if (pl_flag & TTM_PL_FLAG_VRAM) + gbo->placements[c++].flags = TTM_PL_FLAG_WC | + TTM_PL_FLAG_UNCACHED | + TTM_PL_FLAG_VRAM; + + if (pl_flag & TTM_PL_FLAG_SYSTEM) + gbo->placements[c++].flags = TTM_PL_MASK_CACHING | + TTM_PL_FLAG_SYSTEM; + + if (!c) + gbo->placements[c++].flags = TTM_PL_MASK_CACHING | + TTM_PL_FLAG_SYSTEM; + + gbo->placement.num_placement = c; + gbo->placement.num_busy_placement = c; + + for (i = 0; i < c; ++i) { + gbo->placements[i].fpfn = 0; + gbo->placements[i].lpfn = 0; + } +} + +static int drm_gem_vram_init(struct drm_device *dev, + struct ttm_bo_device *bdev, + struct drm_gem_vram_object *gbo, + size_t size, unsigned long pg_align, + bool interruptible) +{ + int ret; + size_t acc_size; + + ret = drm_gem_object_init(dev, &gbo->gem, size); + if (ret) + return ret; + + acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo)); + + gbo->bo.bdev = bdev; + drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM); + + ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device, + &gbo->placement, pg_align, interruptible, acc_size, + NULL, NULL, ttm_buffer_object_destroy); + if (ret) + goto err_drm_gem_object_release; + + return 0; + +err_drm_gem_object_release: + drm_gem_object_release(&gbo->gem); + return ret; +} + +/** + * drm_gem_vram_create() - Creates a VRAM-backed GEM object + * @dev: the DRM device + * @bdev: the TTM BO device backing the object + * @size: the buffer size in bytes + * @pg_align: the buffer's alignment in multiples of the page size + * @interruptible: sleep interruptible if waiting for memory + * + * Returns: + * A new instance of &struct drm_gem_vram_object on success, or + * an ERR_PTR()-encoded error code otherwise. + */ +struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, + struct ttm_bo_device *bdev, + size_t size, + unsigned long pg_align, + bool interruptible) +{ + struct drm_gem_vram_object *gbo; + int ret; + + gbo = kzalloc(sizeof(*gbo), GFP_KERNEL); + if (!gbo) + return ERR_PTR(-ENOMEM); + + ret = drm_gem_vram_init(dev, bdev, gbo, size, pg_align, interruptible); + if (ret < 0) + goto err_kfree; + + return gbo; + +err_kfree: + kfree(gbo); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(drm_gem_vram_create); + +/** + * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object + * @gbo: the GEM VRAM object + * + * See ttm_bo_put() for more information. + */ +void drm_gem_vram_put(struct drm_gem_vram_object *gbo) +{ + ttm_bo_put(&gbo->bo); +} +EXPORT_SYMBOL(drm_gem_vram_put); + +/** + * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset + * @gbo: the GEM VRAM object + * + * See drm_vma_node_offset_addr() for more information. + * + * Returns: + * The buffer object's offset for userspace mappings on success, or + * 0 if no offset is allocated. + */ +u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo) +{ + return drm_vma_node_offset_addr(&gbo->bo.vma_node); +} +EXPORT_SYMBOL(drm_gem_vram_mmap_offset); + +/** + * drm_gem_vram_offset() - \ + Returns a GEM VRAM object's offset in video memory + * @gbo: the GEM VRAM object + * + * This function returns the buffer object's offset in the device's video + * memory. The buffer object has to be pinned to %TTM_PL_VRAM. + * + * Returns: + * The buffer object's offset in video memory on success, or + * a negative errno code otherwise. + */ +s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo) +{ + if (WARN_ON_ONCE(!gbo->pin_count)) + return (s64)-ENODEV; + return gbo->bo.offset; +} +EXPORT_SYMBOL(drm_gem_vram_offset); + +/** + * drm_gem_vram_pin() - Pins a GEM VRAM object in a region. + * @gbo: the GEM VRAM object + * @pl_flag: a bitmask of possible memory regions + * + * Pinning a buffer object ensures that it is not evicted from + * a memory region. A pinned buffer object has to be unpinned before + * it can be pinned to another region. If the pl_flag argument is 0, + * the buffer is pinned at its current location (video RAM or system + * memory). + * + * Returns: + * 0 on success, or + * a negative error code otherwise. + */ +int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag) +{ + int i, ret; + struct ttm_operation_ctx ctx = { false, false }; + + ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); + if (ret < 0) + return ret; + + if (gbo->pin_count) + goto out; + + if (pl_flag) + drm_gem_vram_placement(gbo, pl_flag); + + for (i = 0; i < gbo->placement.num_placement; ++i) + gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT; + + ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx); + if (ret < 0) + goto err_ttm_bo_unreserve; + +out: + ++gbo->pin_count; + ttm_bo_unreserve(&gbo->bo); + + return 0; + +err_ttm_bo_unreserve: + ttm_bo_unreserve(&gbo->bo); + return ret; +} +EXPORT_SYMBOL(drm_gem_vram_pin); + +/** + * drm_gem_vram_unpin() - Unpins a GEM VRAM object + * @gbo: the GEM VRAM object + * + * Returns: + * 0 on success, or + * a negative error code otherwise. + */ +int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo) +{ + int i, ret; + struct ttm_operation_ctx ctx = { false, false }; + + ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); + if (ret < 0) + return ret; + + if (WARN_ON_ONCE(!gbo->pin_count)) + goto out; + + --gbo->pin_count; + if (gbo->pin_count) + goto out; + + for (i = 0; i < gbo->placement.num_placement ; ++i) + gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT; + + ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx); + if (ret < 0) + goto err_ttm_bo_unreserve; + +out: + ttm_bo_unreserve(&gbo->bo); + + return 0; + +err_ttm_bo_unreserve: + ttm_bo_unreserve(&gbo->bo); + return ret; +} +EXPORT_SYMBOL(drm_gem_vram_unpin); + +/** + * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space + * @gbo: the GEM VRAM object + * @map: establish a mapping if necessary + * @is_iomem: returns true if the mapped memory is I/O memory, or false \ + otherwise; can be NULL + * + * This function maps the buffer object into the kernel's address space + * or returns the current mapping. If the parameter map is false, the + * function only queries the current mapping, but does not establish a + * new one. + * + * Returns: + * The buffers virtual address if mapped, or + * NULL if not mapped, or + * an ERR_PTR()-encoded error code otherwise. + */ +void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map, + bool *is_iomem) +{ + int ret; + struct ttm_bo_kmap_obj *kmap = &gbo->kmap; + + if (kmap->virtual || !map) + goto out; + + ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap); + if (ret) + return ERR_PTR(ret); + +out: + if (!is_iomem) + return kmap->virtual; + if (!kmap->virtual) { + *is_iomem = false; + return NULL; + } + return ttm_kmap_obj_virtual(kmap, is_iomem); +} +EXPORT_SYMBOL(drm_gem_vram_kmap); + +/** + * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object + * @gbo: the GEM VRAM object + */ +void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo) +{ + struct ttm_bo_kmap_obj *kmap = &gbo->kmap; + + if (!kmap->virtual) + return; + + ttm_bo_kunmap(kmap); + kmap->virtual = NULL; +} +EXPORT_SYMBOL(drm_gem_vram_kunmap); + +/** + * drm_gem_vram_fill_create_dumb() - \ + Helper for implementing &struct drm_driver.dumb_create + * @file: the DRM file + * @dev: the DRM device + * @bdev: the TTM BO device managing the buffer object + * @pg_align: the buffer's alignment in multiples of the page size + * @interruptible: sleep interruptible if waiting for memory + * @args: the arguments as provided to \ + &struct drm_driver.dumb_create + * + * This helper function fills &struct drm_mode_create_dumb, which is used + * by &struct drm_driver.dumb_create. Implementations of this interface + * should forwards their arguments to this helper, plus the driver-specific + * parameters. + * + * Returns: + * 0 on success, or + * a negative error code otherwise. + */ +int drm_gem_vram_fill_create_dumb(struct drm_file *file, + struct drm_device *dev, + struct ttm_bo_device *bdev, + unsigned long pg_align, + bool interruptible, + struct drm_mode_create_dumb *args) +{ + size_t pitch, size; + struct drm_gem_vram_object *gbo; + int ret; + u32 handle; + + pitch = args->width * ((args->bpp + 7) / 8); + size = pitch * args->height; + + size = roundup(size, PAGE_SIZE); + if (!size) + return -EINVAL; + + gbo = drm_gem_vram_create(dev, bdev, size, pg_align, interruptible); + if (IS_ERR(gbo)) + return PTR_ERR(gbo); + + ret = drm_gem_handle_create(file, &gbo->gem, &handle); + if (ret) + goto err_drm_gem_object_put_unlocked; + + drm_gem_object_put_unlocked(&gbo->gem); + + args->pitch = pitch; + args->size = size; + args->handle = handle; + + return 0; + +err_drm_gem_object_put_unlocked: + drm_gem_object_put_unlocked(&gbo->gem); + return ret; +} +EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb); + +/* + * Helpers for struct ttm_bo_driver + */ + +static bool drm_is_gem_vram(struct ttm_buffer_object *bo) +{ + return (bo->destroy == ttm_buffer_object_destroy); +} + +/** + * drm_gem_vram_bo_driver_evict_flags() - \ + Implements &struct ttm_bo_driver.evict_flags + * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo + * @pl: TTM placement information. + */ +void drm_gem_vram_bo_driver_evict_flags(struct ttm_buffer_object *bo, + struct ttm_placement *pl) +{ + struct drm_gem_vram_object *gbo; + + /* TTM may pass BOs that are not GEM VRAM BOs. */ + if (!drm_is_gem_vram(bo)) + return; + + gbo = drm_gem_vram_of_bo(bo); + drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM); + *pl = gbo->placement; +} +EXPORT_SYMBOL(drm_gem_vram_bo_driver_evict_flags); + +/** + * drm_gem_vram_bo_driver_verify_access() - \ + Implements &struct ttm_bo_driver.verify_access + * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo + * @filp: File pointer. + * + * Returns: + * 0 on success, or + * a negative errno code otherwise. + */ +int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo, + struct file *filp) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo); + + return drm_vma_node_verify_access(&gbo->gem.vma_node, + filp->private_data); +} +EXPORT_SYMBOL(drm_gem_vram_bo_driver_verify_access); + +/* + * drm_gem_vram_mm_funcs - Functions for &struct drm_vram_mm + * + * Most users of @struct drm_gem_vram_object will also use + * @struct drm_vram_mm. This instance of &struct drm_vram_mm_funcs + * can be used to connect both. + */ +const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs = { + .evict_flags = drm_gem_vram_bo_driver_evict_flags, + .verify_access = drm_gem_vram_bo_driver_verify_access +}; +EXPORT_SYMBOL(drm_gem_vram_mm_funcs); + +/* + * Helpers for struct drm_driver + */ + +/** + * drm_gem_vram_driver_gem_free_object_unlocked() - \ + Implements &struct drm_driver.gem_free_object_unlocked + * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem + */ +void drm_gem_vram_driver_gem_free_object_unlocked(struct drm_gem_object *gem) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + drm_gem_vram_put(gbo); +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_free_object_unlocked); + +/** + * drm_gem_vram_driver_create_dumb() - \ + Implements &struct drm_driver.dumb_create + * @file: the DRM file + * @dev: the DRM device + * @args: the arguments as provided to \ + &struct drm_driver.dumb_create + * + * This function requires the driver to use @drm_device.vram_mm for its + * instance of VRAM MM. + * + * Returns: + * 0 on success, or + * a negative error code otherwise. + */ +int drm_gem_vram_driver_dumb_create(struct drm_file *file, + struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized")) + return -EINVAL; + + return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0, + false, args); +} +EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create); + +/** + * drm_gem_vram_driver_dumb_mmap_offset() - \ + Implements &struct drm_driver.dumb_mmap_offset + * @file: DRM file pointer. + * @dev: DRM device. + * @handle: GEM handle + * @offset: Returns the mapping's memory offset on success + * + * Returns: + * 0 on success, or + * a negative errno code otherwise. + */ +int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file, + struct drm_device *dev, + uint32_t handle, uint64_t *offset) +{ + struct drm_gem_object *gem; + struct drm_gem_vram_object *gbo; + + gem = drm_gem_object_lookup(file, handle); + if (!gem) + return -ENOENT; + + gbo = drm_gem_vram_of_gem(gem); + *offset = drm_gem_vram_mmap_offset(gbo); + + drm_gem_object_put_unlocked(gem); + + return 0; +} +EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset); + +/* + * PRIME helpers for struct drm_driver + */ + +/** + * drm_gem_vram_driver_gem_prime_pin() - \ + Implements &struct drm_driver.gem_prime_pin + * @gem: The GEM object to pin + * + * Returns: + * 0 on success, or + * a negative errno code otherwise. + */ +int drm_gem_vram_driver_gem_prime_pin(struct drm_gem_object *gem) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + /* Fbdev console emulation is the use case of these PRIME + * helpers. This may involve updating a hardware buffer from + * a shadow FB. We pin the buffer to it's current location + * (either video RAM or system memory) to prevent it from + * being relocated during the update operation. If you require + * the buffer to be pinned to VRAM, implement a callback that + * sets the flags accordingly. + */ + return drm_gem_vram_pin(gbo, 0); +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_pin); + +/** + * drm_gem_vram_driver_gem_prime_unpin() - \ + Implements &struct drm_driver.gem_prime_unpin + * @gem: The GEM object to unpin + */ +void drm_gem_vram_driver_gem_prime_unpin(struct drm_gem_object *gem) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + drm_gem_vram_unpin(gbo); +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_unpin); + +/** + * drm_gem_vram_driver_gem_prime_vmap() - \ + Implements &struct drm_driver.gem_prime_vmap + * @gem: The GEM object to map + * + * Returns: + * The buffers virtual address on success, or + * NULL otherwise. + */ +void *drm_gem_vram_driver_gem_prime_vmap(struct drm_gem_object *gem) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + int ret; + void *base; + + ret = drm_gem_vram_pin(gbo, 0); + if (ret) + return NULL; + base = drm_gem_vram_kmap(gbo, true, NULL); + if (IS_ERR(base)) { + drm_gem_vram_unpin(gbo); + return NULL; + } + return base; +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_vmap); + +/** + * drm_gem_vram_driver_gem_prime_vunmap() - \ + Implements &struct drm_driver.gem_prime_vunmap + * @gem: The GEM object to unmap + * @vaddr: The mapping's base address + */ +void drm_gem_vram_driver_gem_prime_vunmap(struct drm_gem_object *gem, + void *vaddr) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + drm_gem_vram_kunmap(gbo); + drm_gem_vram_unpin(gbo); +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_vunmap); + +/** + * drm_gem_vram_driver_gem_prime_mmap() - \ + Implements &struct drm_driver.gem_prime_mmap + * @gem: The GEM object to map + * @vma: The VMA describing the mapping + * + * Returns: + * 0 on success, or + * a negative errno code otherwise. + */ +int drm_gem_vram_driver_gem_prime_mmap(struct drm_gem_object *gem, + struct vm_area_struct *vma) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + gbo->gem.vma_node.vm_node.start = gbo->bo.vma_node.vm_node.start; + return drm_gem_prime_mmap(gem, vma); +} +EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_mmap); |