// SPDX-License-Identifier: GPL-2.0-or-later #include <linux/iosys-map.h> #include <linux/module.h> #include <drm/drm_debugfs.h> #include <drm/drm_device.h> #include <drm/drm_drv.h> #include <drm/drm_file.h> #include <drm/drm_framebuffer.h> #include <drm/drm_gem_atomic_helper.h> #include <drm/drm_gem_framebuffer_helper.h> #include <drm/drm_gem_ttm_helper.h> #include <drm/drm_gem_vram_helper.h> #include <drm/drm_managed.h> #include <drm/drm_mode.h> #include <drm/drm_plane.h> #include <drm/drm_prime.h> #include <drm/drm_simple_kms_helper.h> #include <drm/ttm/ttm_range_manager.h> #include <drm/ttm/ttm_tt.h> static const struct drm_gem_object_funcs drm_gem_vram_object_funcs; /** * DOC: overview * * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM * buffer object that is backed by video RAM (VRAM). It can be used for * framebuffer devices with dedicated memory. * * The data structure &struct drm_vram_mm and its helpers implement a memory * manager for simple framebuffer devices with dedicated video memory. GEM * VRAM buffer objects are either placed in the video memory or remain evicted * to system memory. * * With the GEM interface userspace applications create, manage and destroy * graphics buffers, such as an on-screen framebuffer. GEM does not provide * an implementation of these interfaces. It's up to the DRM driver to * provide an implementation that suits the hardware. If the hardware device * contains dedicated video memory, the DRM driver can use the VRAM helper * library. Each active buffer object is stored in video RAM. Active * buffer are used for drawing the current frame, typically something like * the frame's scanout buffer or the cursor image. If there's no more space * left in VRAM, inactive GEM objects can be moved to system memory. * * To initialize the VRAM helper library call drmm_vram_helper_init(). * The function allocates and initializes an instance of &struct drm_vram_mm * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize * &struct file_operations; as illustrated below. * * .. code-block:: c * * struct file_operations fops ={ * .owner = THIS_MODULE, * DRM_VRAM_MM_FILE_OPERATION * }; * struct drm_driver drv = { * .driver_feature = DRM_ ... , * .fops = &fops, * DRM_GEM_VRAM_DRIVER * }; * * int init_drm_driver() * { * struct drm_device *dev; * uint64_t vram_base; * unsigned long vram_size; * int ret; * * // setup device, vram base and size * // ... * * ret = drmm_vram_helper_init(dev, vram_base, vram_size); * if (ret) * return ret; * return 0; * } * * This creates an instance of &struct drm_vram_mm, exports DRM userspace * interfaces for GEM buffer management and initializes file operations to * allow for accessing created GEM buffers. With this setup, the DRM driver * manages an area of video RAM with VRAM MM and provides GEM VRAM objects * to userspace. * * You don't have to clean up the instance of VRAM MM. * drmm_vram_helper_init() is a managed interface that installs a * clean-up handler to run during the DRM device's release. * * For drawing or scanout operations, rsp. buffer objects have to be pinned * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards. * * A buffer object that is pinned in video RAM has a fixed address within that * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically * it's used to program the hardware's scanout engine for framebuffers, set * the cursor overlay's image for a mouse cursor, or use it as input to the * hardware's drawing engine. * * To access a buffer object's memory from the DRM driver, call * drm_gem_vram_vmap(). It maps the buffer into kernel address * space and returns the memory address. Use drm_gem_vram_vunmap() to * release the mapping. */ /* * Buffer-objects helpers */ static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo) { … } static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo) { … } static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo) { … } static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, unsigned long pl_flag) { … } /** * drm_gem_vram_create() - Creates a VRAM-backed GEM object * @dev: the DRM device * @size: the buffer size in bytes * @pg_align: the buffer's alignment in multiples of the page size * * GEM objects are allocated by calling struct drm_driver.gem_create_object, * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM * object functions in struct drm_driver.gem_create_object. If no functions * are set, the new GEM object will use the default functions from GEM VRAM * helpers. * * 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, size_t size, unsigned long pg_align) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo) { … } /** * 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) { … } EXPORT_SYMBOL(…); static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo, unsigned long pl_flag) { … } /** * 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). * * Small buffer objects, such as cursor images, can lead to memory * fragmentation if they are pinned in the middle of video RAM. This * is especially a problem on devices with only a small amount of * video RAM. Fragmentation can prevent the primary framebuffer from * fitting in, even though there's enough memory overall. The modifier * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned * at the high end of the memory region to avoid fragmentation. * * 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) { … } EXPORT_SYMBOL(…); static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo) { … } /** * 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) { … } EXPORT_SYMBOL(…); /** * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address * space * @gbo: The GEM VRAM object to map * @map: Returns the kernel virtual address of the VRAM GEM object's backing * store. * * The vmap function pins a GEM VRAM object to its current location, either * system or video memory, and maps its buffer into kernel address space. * As pinned object cannot be relocated, you should avoid pinning objects * permanently. Call drm_gem_vram_vunmap() with the returned address to * unmap and unpin the GEM VRAM object. * * Returns: * 0 on success, or a negative error code otherwise. */ int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) { … } EXPORT_SYMBOL(…); /** * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object * @gbo: The GEM VRAM object to unmap * @map: Kernel virtual address where the VRAM GEM object was mapped * * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See * the documentation for drm_gem_vram_vmap() for more information. */ void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) { … } EXPORT_SYMBOL(…); /** * drm_gem_vram_fill_create_dumb() - Helper for implementing * &struct drm_driver.dumb_create * * @file: the DRM file * @dev: the DRM device * @pg_align: the buffer's alignment in multiples of the page size * @pitch_align: the scanline's alignment in powers of 2 * @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, unsigned long pg_align, unsigned long pitch_align, struct drm_mode_create_dumb *args) { … } EXPORT_SYMBOL(…); /* * Helpers for struct ttm_device_funcs */ static bool drm_is_gem_vram(struct ttm_buffer_object *bo) { … } static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo, struct ttm_placement *pl) { … } static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo) { … } static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo, bool evict, struct ttm_operation_ctx *ctx, struct ttm_resource *new_mem) { … } /* * 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) { … } /* * Helpers for dump buffers */ /** * drm_gem_vram_driver_dumb_create() - 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) { … } EXPORT_SYMBOL(…); /* * Helpers for struct drm_plane_helper_funcs */ static void __drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, struct drm_plane_state *state, unsigned int num_planes) { … } /** * drm_gem_vram_plane_helper_prepare_fb() - Implements &struct * drm_plane_helper_funcs.prepare_fb * @plane: a DRM plane * @new_state: the plane's new state * * During plane updates, this function sets the plane's fence and * pins the GEM VRAM objects of the plane's new framebuffer to VRAM. * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them. * * Returns: * 0 on success, or * a negative errno code otherwise. */ int drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *new_state) { … } EXPORT_SYMBOL(…); /** * drm_gem_vram_plane_helper_cleanup_fb() - Implements &struct * drm_plane_helper_funcs.cleanup_fb * @plane: a DRM plane * @old_state: the plane's old state * * During plane updates, this function unpins the GEM VRAM * objects of the plane's old framebuffer from VRAM. Complements * drm_gem_vram_plane_helper_prepare_fb(). */ void drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, struct drm_plane_state *old_state) { … } EXPORT_SYMBOL(…); /* * Helpers for struct drm_simple_display_pipe_funcs */ /** * drm_gem_vram_simple_display_pipe_prepare_fb() - Implements &struct * drm_simple_display_pipe_funcs.prepare_fb * @pipe: a simple display pipe * @new_state: the plane's new state * * During plane updates, this function pins the GEM VRAM * objects of the plane's new framebuffer to VRAM. Call * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them. * * Returns: * 0 on success, or * a negative errno code otherwise. */ int drm_gem_vram_simple_display_pipe_prepare_fb( struct drm_simple_display_pipe *pipe, struct drm_plane_state *new_state) { … } EXPORT_SYMBOL(…); /** * drm_gem_vram_simple_display_pipe_cleanup_fb() - Implements &struct * drm_simple_display_pipe_funcs.cleanup_fb * @pipe: a simple display pipe * @old_state: the plane's old state * * During plane updates, this function unpins the GEM VRAM * objects of the plane's old framebuffer from VRAM. Complements * drm_gem_vram_simple_display_pipe_prepare_fb(). */ void drm_gem_vram_simple_display_pipe_cleanup_fb( struct drm_simple_display_pipe *pipe, struct drm_plane_state *old_state) { … } EXPORT_SYMBOL(…); /* * 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) { … } /** * 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) { … } /** * drm_gem_vram_object_vmap() - * Implements &struct drm_gem_object_funcs.vmap * @gem: The GEM object to map * @map: Returns the kernel virtual address of the VRAM GEM object's backing * store. * * Returns: * 0 on success, or a negative error code otherwise. */ static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct iosys_map *map) { … } /** * drm_gem_vram_object_vunmap() - * Implements &struct drm_gem_object_funcs.vunmap * @gem: The GEM object to unmap * @map: Kernel virtual address where the VRAM GEM object was mapped */ static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct iosys_map *map) { … } /* * GEM object funcs */ static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = …; /* * VRAM memory manager */ /* * TTM TT */ static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt) { … } /* * TTM BO device */ static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo, uint32_t page_flags) { … } static void bo_driver_evict_flags(struct ttm_buffer_object *bo, struct ttm_placement *placement) { … } static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo) { … } static int bo_driver_move(struct ttm_buffer_object *bo, bool evict, struct ttm_operation_ctx *ctx, struct ttm_resource *new_mem, struct ttm_place *hop) { … } static int bo_driver_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) { … } static struct ttm_device_funcs bo_driver = …; /* * struct drm_vram_mm */ static int drm_vram_mm_debugfs(struct seq_file *m, void *data) { … } static const struct drm_debugfs_info drm_vram_mm_debugfs_list[] = …; /** * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file. * * @minor: drm minor device. * */ void drm_vram_mm_debugfs_init(struct drm_minor *minor) { … } EXPORT_SYMBOL(…); static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev, uint64_t vram_base, size_t vram_size) { … } static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm) { … } /* * Helpers for integration with struct drm_device */ static struct drm_vram_mm *drm_vram_helper_alloc_mm(struct drm_device *dev, uint64_t vram_base, size_t vram_size) { … } static void drm_vram_helper_release_mm(struct drm_device *dev) { … } static void drm_vram_mm_release(struct drm_device *dev, void *ptr) { … } /** * drmm_vram_helper_init - Initializes a device's instance of * &struct drm_vram_mm * @dev: the DRM device * @vram_base: the base address of the video memory * @vram_size: the size of the video memory in bytes * * Creates a new instance of &struct drm_vram_mm and stores it in * struct &drm_device.vram_mm. The instance is auto-managed and cleaned * up as part of device cleanup. Calling this function multiple times * will generate an error message. * * Returns: * 0 on success, or a negative errno code otherwise. */ int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base, size_t vram_size) { … } EXPORT_SYMBOL(…); /* * Mode-config helpers */ static enum drm_mode_status drm_vram_helper_mode_valid_internal(struct drm_device *dev, const struct drm_display_mode *mode, unsigned long max_bpp) { … } /** * drm_vram_helper_mode_valid - Tests if a display mode's * framebuffer fits into the available video memory. * @dev: the DRM device * @mode: the mode to test * * This function tests if enough video memory is available for using the * specified display mode. Atomic modesetting requires importing the * designated framebuffer into video memory before evicting the active * one. Hence, any framebuffer may consume at most half of the available * VRAM. Display modes that require a larger framebuffer can not be used, * even if the CRTC does support them. Each framebuffer is assumed to * have 32-bit color depth. * * Note: * The function can only test if the display mode is supported in * general. If there are too many framebuffers pinned to video memory, * a display mode may still not be usable in practice. The color depth of * 32-bit fits all current use case. A more flexible test can be added * when necessary. * * Returns: * MODE_OK if the display mode is supported, or an error code of type * enum drm_mode_status otherwise. */ enum drm_mode_status drm_vram_helper_mode_valid(struct drm_device *dev, const struct drm_display_mode *mode) { … } EXPORT_SYMBOL(…); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
Codebase Browser
linux