// SPDX-License-Identifier: GPL-2.0-or-later #include #include #include #include #include #include static const struct drm_gem_object_funcs drm_gem_vram_object_funcs; /** * 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->bo.base); } 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; if (!gbo->bo.base.funcs) gbo->bo.base.funcs = &drm_gem_vram_object_funcs; ret = drm_gem_object_init(dev, &gbo->bo.base, 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->bo.base); 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.base.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->bo.base, &handle); if (ret) goto err_drm_gem_object_put_unlocked; drm_gem_object_put_unlocked(&gbo->bo.base); args->pitch = pitch; args->size = size; args->handle = handle; return 0; err_drm_gem_object_put_unlocked: drm_gem_object_put_unlocked(&gbo->bo.base); 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->bo.base.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_gem_object_funcs */ /** * drm_gem_vram_object_free() - \ Implements &struct drm_gem_object_funcs.free * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem */ static void drm_gem_vram_object_free(struct drm_gem_object *gem) { struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); drm_gem_vram_put(gbo); } /* * Helpers for dump buffers */ /** * 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 */ /** * drm_gem_vram_object_pin() - \ Implements &struct drm_gem_object_funcs.pin * @gem: The GEM object to pin * * Returns: * 0 on success, or * a negative errno code otherwise. */ static int drm_gem_vram_object_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); } /** * drm_gem_vram_object_unpin() - \ Implements &struct drm_gem_object_funcs.unpin * @gem: The GEM object to unpin */ static void drm_gem_vram_object_unpin(struct drm_gem_object *gem) { struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); drm_gem_vram_unpin(gbo); } /** * drm_gem_vram_object_vmap() - \ Implements &struct drm_gem_object_funcs.vmap * @gem: The GEM object to map * * Returns: * The buffers virtual address on success, or * NULL otherwise. */ static void *drm_gem_vram_object_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; } /** * drm_gem_vram_object_vunmap() - \ Implements &struct drm_gem_object_funcs.vunmap * @gem: The GEM object to unmap * @vaddr: The mapping's base address */ static void drm_gem_vram_object_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); } /* * GEM object funcs */ static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = { .free = drm_gem_vram_object_free, .pin = drm_gem_vram_object_pin, .unpin = drm_gem_vram_object_unpin, .vmap = drm_gem_vram_object_vmap, .vunmap = drm_gem_vram_object_vunmap };