/************************************************************************** * * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * **************************************************************************/ /* * Authors: Thomas Hellstrom */ #ifndef _TTM_BO_DRIVER_H_ #define _TTM_BO_DRIVER_H_ #include #include #include #include #include #include #include #include "ttm_bo_api.h" #include "ttm_memory.h" #include "ttm_module.h" #include "ttm_placement.h" #define TTM_MAX_BO_PRIORITY 4U struct ttm_backend_func { /** * struct ttm_backend_func member bind * * @ttm: Pointer to a struct ttm_tt. * @bo_mem: Pointer to a struct ttm_mem_reg describing the * memory type and location for binding. * * Bind the backend pages into the aperture in the location * indicated by @bo_mem. This function should be able to handle * differences between aperture and system page sizes. */ int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem); /** * struct ttm_backend_func member unbind * * @ttm: Pointer to a struct ttm_tt. * * Unbind previously bound backend pages. This function should be * able to handle differences between aperture and system page sizes. */ int (*unbind) (struct ttm_tt *ttm); /** * struct ttm_backend_func member destroy * * @ttm: Pointer to a struct ttm_tt. * * Destroy the backend. This will be call back from ttm_tt_destroy so * don't call ttm_tt_destroy from the callback or infinite loop. */ void (*destroy) (struct ttm_tt *ttm); }; #define TTM_PAGE_FLAG_WRITE (1 << 3) #define TTM_PAGE_FLAG_SWAPPED (1 << 4) #define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5) #define TTM_PAGE_FLAG_ZERO_ALLOC (1 << 6) #define TTM_PAGE_FLAG_DMA32 (1 << 7) #define TTM_PAGE_FLAG_SG (1 << 8) enum ttm_caching_state { tt_uncached, tt_wc, tt_cached }; /** * struct ttm_tt * * @bdev: Pointer to a struct ttm_bo_device. * @func: Pointer to a struct ttm_backend_func that describes * the backend methods. * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL * pointer. * @pages: Array of pages backing the data. * @num_pages: Number of pages in the page array. * @bdev: Pointer to the current struct ttm_bo_device. * @be: Pointer to the ttm backend. * @swap_storage: Pointer to shmem struct file for swap storage. * @caching_state: The current caching state of the pages. * @state: The current binding state of the pages. * * This is a structure holding the pages, caching- and aperture binding * status for a buffer object that isn't backed by fixed (VRAM / AGP) * memory. */ struct ttm_tt { struct ttm_bo_device *bdev; struct ttm_backend_func *func; struct page *dummy_read_page; struct page **pages; uint32_t page_flags; unsigned long num_pages; struct sg_table *sg; /* for SG objects via dma-buf */ struct ttm_bo_global *glob; struct file *swap_storage; enum ttm_caching_state caching_state; enum { tt_bound, tt_unbound, tt_unpopulated, } state; }; /** * struct ttm_dma_tt * * @ttm: Base ttm_tt struct. * @dma_address: The DMA (bus) addresses of the pages * @pages_list: used by some page allocation backend * * This is a structure holding the pages, caching- and aperture binding * status for a buffer object that isn't backed by fixed (VRAM / AGP) * memory. */ struct ttm_dma_tt { struct ttm_tt ttm; dma_addr_t *dma_address; struct list_head pages_list; }; #define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */ #define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */ #define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */ struct ttm_mem_type_manager; struct ttm_mem_type_manager_func { /** * struct ttm_mem_type_manager member init * * @man: Pointer to a memory type manager. * @p_size: Implementation dependent, but typically the size of the * range to be managed in pages. * * Called to initialize a private range manager. The function is * expected to initialize the man::priv member. * Returns 0 on success, negative error code on failure. */ int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size); /** * struct ttm_mem_type_manager member takedown * * @man: Pointer to a memory type manager. * * Called to undo the setup done in init. All allocated resources * should be freed. */ int (*takedown)(struct ttm_mem_type_manager *man); /** * struct ttm_mem_type_manager member get_node * * @man: Pointer to a memory type manager. * @bo: Pointer to the buffer object we're allocating space for. * @placement: Placement details. * @flags: Additional placement flags. * @mem: Pointer to a struct ttm_mem_reg to be filled in. * * This function should allocate space in the memory type managed * by @man. Placement details if * applicable are given by @placement. If successful, * @mem::mm_node should be set to a non-null value, and * @mem::start should be set to a value identifying the beginning * of the range allocated, and the function should return zero. * If the memory region accommodate the buffer object, @mem::mm_node * should be set to NULL, and the function should return 0. * If a system error occurred, preventing the request to be fulfilled, * the function should return a negative error code. * * Note that @mem::mm_node will only be dereferenced by * struct ttm_mem_type_manager functions and optionally by the driver, * which has knowledge of the underlying type. * * This function may not be called from within atomic context, so * an implementation can and must use either a mutex or a spinlock to * protect any data structures managing the space. */ int (*get_node)(struct ttm_mem_type_manager *man, struct ttm_buffer_object *bo, const struct ttm_place *place, struct ttm_mem_reg *mem); /** * struct ttm_mem_type_manager member put_node * * @man: Pointer to a memory type manager. * @mem: Pointer to a struct ttm_mem_reg to be filled in. * * This function frees memory type resources previously allocated * and that are identified by @mem::mm_node and @mem::start. May not * be called from within atomic context. */ void (*put_node)(struct ttm_mem_type_manager *man, struct ttm_mem_reg *mem); /** * struct ttm_mem_type_manager member debug * * @man: Pointer to a memory type manager. * @printer: Prefix to be used in printout to identify the caller. * * This function is called to print out the state of the memory * type manager to aid debugging of out-of-memory conditions. * It may not be called from within atomic context. */ void (*debug)(struct ttm_mem_type_manager *man, struct drm_printer *printer); }; /** * struct ttm_mem_type_manager * * @has_type: The memory type has been initialized. * @use_type: The memory type is enabled. * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory * managed by this memory type. * @gpu_offset: If used, the GPU offset of the first managed page of * fixed memory or the first managed location in an aperture. * @size: Size of the managed region. * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX, * as defined in ttm_placement_common.h * @default_caching: The default caching policy used for a buffer object * placed in this memory type if the user doesn't provide one. * @func: structure pointer implementing the range manager. See above * @priv: Driver private closure for @func. * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions * reserved by the TTM vm system. * @io_reserve_lru: Optional lru list for unreserving io mem regions. * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain * @move_lock: lock for move fence * static information. bdev::driver::io_mem_free is never used. * @lru: The lru list for this memory type. * @move: The fence of the last pipelined move operation. * * This structure is used to identify and manage memory types for a device. * It's set up by the ttm_bo_driver::init_mem_type method. */ struct ttm_mem_type_manager { struct ttm_bo_device *bdev; /* * No protection. Constant from start. */ bool has_type; bool use_type; uint32_t flags; uint64_t gpu_offset; /* GPU address space is independent of CPU word size */ uint64_t size; uint32_t available_caching; uint32_t default_caching; const struct ttm_mem_type_manager_func *func; void *priv; struct mutex io_reserve_mutex; bool use_io_reserve_lru; bool io_reserve_fastpath; spinlock_t move_lock; /* * Protected by @io_reserve_mutex: */ struct list_head io_reserve_lru; /* * Protected by the global->lru_lock. */ struct list_head lru[TTM_MAX_BO_PRIORITY]; /* * Protected by @move_lock. */ struct dma_fence *move; }; /** * struct ttm_bo_driver * * @create_ttm_backend_entry: Callback to create a struct ttm_backend. * @invalidate_caches: Callback to invalidate read caches when a buffer object * has been evicted. * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager * structure. * @evict_flags: Callback to obtain placement flags when a buffer is evicted. * @move: Callback for a driver to hook in accelerated functions to * move a buffer. * If set to NULL, a potentially slow memcpy() move is used. */ struct ttm_bo_driver { /** * ttm_tt_create * * @bdev: pointer to a struct ttm_bo_device: * @size: Size of the data needed backing. * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags. * @dummy_read_page: See struct ttm_bo_device. * * Create a struct ttm_tt to back data with system memory pages. * No pages are actually allocated. * Returns: * NULL: Out of memory. */ struct ttm_tt *(*ttm_tt_create)(struct ttm_bo_device *bdev, unsigned long size, uint32_t page_flags, struct page *dummy_read_page); /** * ttm_tt_populate * * @ttm: The struct ttm_tt to contain the backing pages. * * Allocate all backing pages * Returns: * -ENOMEM: Out of memory. */ int (*ttm_tt_populate)(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx); /** * ttm_tt_unpopulate * * @ttm: The struct ttm_tt to contain the backing pages. * * Free all backing page */ void (*ttm_tt_unpopulate)(struct ttm_tt *ttm); /** * struct ttm_bo_driver member invalidate_caches * * @bdev: the buffer object device. * @flags: new placement of the rebound buffer object. * * A previosly evicted buffer has been rebound in a * potentially new location. Tell the driver that it might * consider invalidating read (texture) caches on the next command * submission as a consequence. */ int (*invalidate_caches)(struct ttm_bo_device *bdev, uint32_t flags); int (*init_mem_type)(struct ttm_bo_device *bdev, uint32_t type, struct ttm_mem_type_manager *man); /** * struct ttm_bo_driver member eviction_valuable * * @bo: the buffer object to be evicted * @place: placement we need room for * * Check with the driver if it is valuable to evict a BO to make room * for a certain placement. */ bool (*eviction_valuable)(struct ttm_buffer_object *bo, const struct ttm_place *place); /** * struct ttm_bo_driver member evict_flags: * * @bo: the buffer object to be evicted * * Return the bo flags for a buffer which is not mapped to the hardware. * These will be placed in proposed_flags so that when the move is * finished, they'll end up in bo->mem.flags */ void (*evict_flags)(struct ttm_buffer_object *bo, struct ttm_placement *placement); /** * struct ttm_bo_driver member move: * * @bo: the buffer to move * @evict: whether this motion is evicting the buffer from * the graphics address space * @ctx: context for this move with parameters * @new_mem: the new memory region receiving the buffer * * Move a buffer between two memory regions. */ int (*move)(struct ttm_buffer_object *bo, bool evict, struct ttm_operation_ctx *ctx, struct ttm_mem_reg *new_mem); /** * struct ttm_bo_driver_member verify_access * * @bo: Pointer to a buffer object. * @filp: Pointer to a struct file trying to access the object. * * Called from the map / write / read methods to verify that the * caller is permitted to access the buffer object. * This member may be set to NULL, which will refuse this kind of * access for all buffer objects. * This function should return 0 if access is granted, -EPERM otherwise. */ int (*verify_access)(struct ttm_buffer_object *bo, struct file *filp); /** * Hook to notify driver about a driver move so it * can do tiling things and book-keeping. * * @evict: whether this move is evicting the buffer from the graphics * address space */ void (*move_notify)(struct ttm_buffer_object *bo, bool evict, struct ttm_mem_reg *new_mem); /* notify the driver we are taking a fault on this BO * and have reserved it */ int (*fault_reserve_notify)(struct ttm_buffer_object *bo); /** * notify the driver that we're about to swap out this bo */ void (*swap_notify)(struct ttm_buffer_object *bo); /** * Driver callback on when mapping io memory (for bo_move_memcpy * for instance). TTM will take care to call io_mem_free whenever * the mapping is not use anymore. io_mem_reserve & io_mem_free * are balanced. */ int (*io_mem_reserve)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); void (*io_mem_free)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); /** * Return the pfn for a given page_offset inside the BO. * * @bo: the BO to look up the pfn for * @page_offset: the offset to look up */ unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo, unsigned long page_offset); /** * Read/write memory buffers for ptrace access * * @bo: the BO to access * @offset: the offset from the start of the BO * @buf: pointer to source/destination buffer * @len: number of bytes to copy * @write: whether to read (0) from or write (non-0) to BO * * If successful, this function should return the number of * bytes copied, -EIO otherwise. If the number of bytes * returned is < len, the function may be called again with * the remainder of the buffer to copy. */ int (*access_memory)(struct ttm_buffer_object *bo, unsigned long offset, void *buf, int len, int write); }; /** * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global. */ struct ttm_bo_global_ref { struct drm_global_reference ref; struct ttm_mem_global *mem_glob; }; /** * struct ttm_bo_global - Buffer object driver global data. * * @mem_glob: Pointer to a struct ttm_mem_global object for accounting. * @dummy_read_page: Pointer to a dummy page used for mapping requests * of unpopulated pages. * @shrink: A shrink callback object used for buffer object swap. * @device_list_mutex: Mutex protecting the device list. * This mutex is held while traversing the device list for pm options. * @lru_lock: Spinlock protecting the bo subsystem lru lists. * @device_list: List of buffer object devices. * @swap_lru: Lru list of buffer objects used for swapping. */ struct ttm_bo_global { /** * Constant after init. */ struct kobject kobj; struct ttm_mem_global *mem_glob; struct page *dummy_read_page; struct mutex device_list_mutex; spinlock_t lru_lock; /** * Protected by device_list_mutex. */ struct list_head device_list; /** * Protected by the lru_lock. */ struct list_head swap_lru[TTM_MAX_BO_PRIORITY]; /** * Internal protection. */ atomic_t bo_count; }; #define TTM_NUM_MEM_TYPES 8 /** * struct ttm_bo_device - Buffer object driver device-specific data. * * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver. * @man: An array of mem_type_managers. * @vma_manager: Address space manager * lru_lock: Spinlock that protects the buffer+device lru lists and * ddestroy lists. * @dev_mapping: A pointer to the struct address_space representing the * device address space. * @wq: Work queue structure for the delayed delete workqueue. * */ struct ttm_bo_device { /* * Constant after bo device init / atomic. */ struct list_head device_list; struct ttm_bo_global *glob; struct ttm_bo_driver *driver; struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES]; /* * Protected by internal locks. */ struct drm_vma_offset_manager vma_manager; /* * Protected by the global:lru lock. */ struct list_head ddestroy; /* * Protected by load / firstopen / lastclose /unload sync. */ struct address_space *dev_mapping; /* * Internal protection. */ struct delayed_work wq; bool need_dma32; }; /** * ttm_flag_masked * * @old: Pointer to the result and original value. * @new: New value of bits. * @mask: Mask of bits to change. * * Convenience function to change a number of bits identified by a mask. */ static inline uint32_t ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask) { *old ^= (*old ^ new) & mask; return *old; } /** * ttm_tt_init * * @ttm: The struct ttm_tt. * @bdev: pointer to a struct ttm_bo_device: * @size: Size of the data needed backing. * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags. * @dummy_read_page: See struct ttm_bo_device. * * Create a struct ttm_tt to back data with system memory pages. * No pages are actually allocated. * Returns: * NULL: Out of memory. */ int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev, unsigned long size, uint32_t page_flags, struct page *dummy_read_page); int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev, unsigned long size, uint32_t page_flags, struct page *dummy_read_page); /** * ttm_tt_fini * * @ttm: the ttm_tt structure. * * Free memory of ttm_tt structure */ void ttm_tt_fini(struct ttm_tt *ttm); void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma); /** * ttm_ttm_bind: * * @ttm: The struct ttm_tt containing backing pages. * @bo_mem: The struct ttm_mem_reg identifying the binding location. * * Bind the pages of @ttm to an aperture location identified by @bo_mem */ int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem); /** * ttm_ttm_destroy: * * @ttm: The struct ttm_tt. * * Unbind, unpopulate and destroy common struct ttm_tt. */ void ttm_tt_destroy(struct ttm_tt *ttm); /** * ttm_ttm_unbind: * * @ttm: The struct ttm_tt. * * Unbind a struct ttm_tt. */ void ttm_tt_unbind(struct ttm_tt *ttm); /** * ttm_tt_swapin: * * @ttm: The struct ttm_tt. * * Swap in a previously swap out ttm_tt. */ int ttm_tt_swapin(struct ttm_tt *ttm); /** * ttm_tt_set_placement_caching: * * @ttm A struct ttm_tt the backing pages of which will change caching policy. * @placement: Flag indicating the desired caching policy. * * This function will change caching policy of any default kernel mappings of * the pages backing @ttm. If changing from cached to uncached or * write-combined, * all CPU caches will first be flushed to make sure the data of the pages * hit RAM. This function may be very costly as it involves global TLB * and cache flushes and potential page splitting / combining. */ int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement); int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage); /** * ttm_tt_unpopulate - free pages from a ttm * * @ttm: Pointer to the ttm_tt structure * * Calls the driver method to free all pages from a ttm */ void ttm_tt_unpopulate(struct ttm_tt *ttm); /* * ttm_bo.c */ /** * ttm_mem_reg_is_pci * * @bdev: Pointer to a struct ttm_bo_device. * @mem: A valid struct ttm_mem_reg. * * Returns true if the memory described by @mem is PCI memory, * false otherwise. */ bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); /** * ttm_bo_mem_space * * @bo: Pointer to a struct ttm_buffer_object. the data of which * we want to allocate space for. * @proposed_placement: Proposed new placement for the buffer object. * @mem: A struct ttm_mem_reg. * @interruptible: Sleep interruptible when sliping. * @no_wait_gpu: Return immediately if the GPU is busy. * * Allocate memory space for the buffer object pointed to by @bo, using * the placement flags in @mem, potentially evicting other idle buffer objects. * This function may sleep while waiting for space to become available. * Returns: * -EBUSY: No space available (only if no_wait == 1). * -ENOMEM: Could not allocate memory for the buffer object, either due to * fragmentation or concurrent allocators. * -ERESTARTSYS: An interruptible sleep was interrupted by a signal. */ int ttm_bo_mem_space(struct ttm_buffer_object *bo, struct ttm_placement *placement, struct ttm_mem_reg *mem, struct ttm_operation_ctx *ctx); void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem); void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem); void ttm_bo_global_release(struct drm_global_reference *ref); int ttm_bo_global_init(struct drm_global_reference *ref); int ttm_bo_device_release(struct ttm_bo_device *bdev); /** * ttm_bo_device_init * * @bdev: A pointer to a struct ttm_bo_device to initialize. * @glob: A pointer to an initialized struct ttm_bo_global. * @driver: A pointer to a struct ttm_bo_driver set up by the caller. * @mapping: The address space to use for this bo. * @file_page_offset: Offset into the device address space that is available * for buffer data. This ensures compatibility with other users of the * address space. * * Initializes a struct ttm_bo_device: * Returns: * !0: Failure. */ int ttm_bo_device_init(struct ttm_bo_device *bdev, struct ttm_bo_global *glob, struct ttm_bo_driver *driver, struct address_space *mapping, uint64_t file_page_offset, bool need_dma32); /** * ttm_bo_unmap_virtual * * @bo: tear down the virtual mappings for this BO */ void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo); /** * ttm_bo_unmap_virtual * * @bo: tear down the virtual mappings for this BO * * The caller must take ttm_mem_io_lock before calling this function. */ void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo); int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo); void ttm_mem_io_free_vm(struct ttm_buffer_object *bo); int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible); void ttm_mem_io_unlock(struct ttm_mem_type_manager *man); void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo); void ttm_bo_add_to_lru(struct ttm_buffer_object *bo); /** * __ttm_bo_reserve: * * @bo: A pointer to a struct ttm_buffer_object. * @interruptible: Sleep interruptible if waiting. * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY. * @ticket: ticket used to acquire the ww_mutex. * * Will not remove reserved buffers from the lru lists. * Otherwise identical to ttm_bo_reserve. * * Returns: * -EDEADLK: The reservation may cause a deadlock. * Release all buffer reservations, wait for @bo to become unreserved and * try again. (only if use_sequence == 1). * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by * a signal. Release all buffer reservations and return to user-space. * -EBUSY: The function needed to sleep, but @no_wait was true * -EALREADY: Bo already reserved using @ticket. This error code will only * be returned if @use_ticket is set to true. */ static inline int __ttm_bo_reserve(struct ttm_buffer_object *bo, bool interruptible, bool no_wait, struct ww_acquire_ctx *ticket) { int ret = 0; if (no_wait) { bool success; if (WARN_ON(ticket)) return -EBUSY; success = reservation_object_trylock(bo->resv); return success ? 0 : -EBUSY; } if (interruptible) ret = reservation_object_lock_interruptible(bo->resv, ticket); else ret = reservation_object_lock(bo->resv, ticket); if (ret == -EINTR) return -ERESTARTSYS; return ret; } /** * ttm_bo_reserve: * * @bo: A pointer to a struct ttm_buffer_object. * @interruptible: Sleep interruptible if waiting. * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY. * @ticket: ticket used to acquire the ww_mutex. * * Locks a buffer object for validation. (Or prevents other processes from * locking it for validation) and removes it from lru lists, while taking * a number of measures to prevent deadlocks. * * Deadlocks may occur when two processes try to reserve multiple buffers in * different order, either by will or as a result of a buffer being evicted * to make room for a buffer already reserved. (Buffers are reserved before * they are evicted). The following algorithm prevents such deadlocks from * occurring: * Processes attempting to reserve multiple buffers other than for eviction, * (typically execbuf), should first obtain a unique 32-bit * validation sequence number, * and call this function with @use_ticket == 1 and @ticket->stamp == the unique * sequence number. If upon call of this function, the buffer object is already * reserved, the validation sequence is checked against the validation * sequence of the process currently reserving the buffer, * and if the current validation sequence is greater than that of the process * holding the reservation, the function returns -EDEADLK. Otherwise it sleeps * waiting for the buffer to become unreserved, after which it retries * reserving. * The caller should, when receiving an -EDEADLK error * release all its buffer reservations, wait for @bo to become unreserved, and * then rerun the validation with the same validation sequence. This procedure * will always guarantee that the process with the lowest validation sequence * will eventually succeed, preventing both deadlocks and starvation. * * Returns: * -EDEADLK: The reservation may cause a deadlock. * Release all buffer reservations, wait for @bo to become unreserved and * try again. (only if use_sequence == 1). * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by * a signal. Release all buffer reservations and return to user-space. * -EBUSY: The function needed to sleep, but @no_wait was true * -EALREADY: Bo already reserved using @ticket. This error code will only * be returned if @use_ticket is set to true. */ static inline int ttm_bo_reserve(struct ttm_buffer_object *bo, bool interruptible, bool no_wait, struct ww_acquire_ctx *ticket) { int ret; WARN_ON(!kref_read(&bo->kref)); ret = __ttm_bo_reserve(bo, interruptible, no_wait, ticket); if (likely(ret == 0)) ttm_bo_del_sub_from_lru(bo); return ret; } /** * ttm_bo_reserve_slowpath: * @bo: A pointer to a struct ttm_buffer_object. * @interruptible: Sleep interruptible if waiting. * @sequence: Set (@bo)->sequence to this value after lock * * This is called after ttm_bo_reserve returns -EAGAIN and we backed off * from all our other reservations. Because there are no other reservations * held by us, this function cannot deadlock any more. */ static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo, bool interruptible, struct ww_acquire_ctx *ticket) { int ret = 0; WARN_ON(!kref_read(&bo->kref)); if (interruptible) ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, ticket); else ww_mutex_lock_slow(&bo->resv->lock, ticket); if (likely(ret == 0)) ttm_bo_del_sub_from_lru(bo); else if (ret == -EINTR) ret = -ERESTARTSYS; return ret; } /** * ttm_bo_unreserve * * @bo: A pointer to a struct ttm_buffer_object. * * Unreserve a previous reservation of @bo. */ static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo) { if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) { spin_lock(&bo->glob->lru_lock); ttm_bo_add_to_lru(bo); spin_unlock(&bo->glob->lru_lock); } reservation_object_unlock(bo->resv); } /* * ttm_bo_util.c */ int ttm_mem_io_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); void ttm_mem_io_free(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); /** * ttm_bo_move_ttm * * @bo: A pointer to a struct ttm_buffer_object. * @interruptible: Sleep interruptible if waiting. * @no_wait_gpu: Return immediately if the GPU is busy. * @new_mem: struct ttm_mem_reg indicating where to move. * * Optimized move function for a buffer object with both old and * new placement backed by a TTM. The function will, if successful, * free any old aperture space, and set (@new_mem)->mm_node to NULL, * and update the (@bo)->mem placement flags. If unsuccessful, the old * data remains untouched, and it's up to the caller to free the * memory space indicated by @new_mem. * Returns: * !0: Failure. */ int ttm_bo_move_ttm(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx, struct ttm_mem_reg *new_mem); /** * ttm_bo_move_memcpy * * @bo: A pointer to a struct ttm_buffer_object. * @interruptible: Sleep interruptible if waiting. * @no_wait_gpu: Return immediately if the GPU is busy. * @new_mem: struct ttm_mem_reg indicating where to move. * * Fallback move function for a mappable buffer object in mappable memory. * The function will, if successful, * free any old aperture space, and set (@new_mem)->mm_node to NULL, * and update the (@bo)->mem placement flags. If unsuccessful, the old * data remains untouched, and it's up to the caller to free the * memory space indicated by @new_mem. * Returns: * !0: Failure. */ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx, struct ttm_mem_reg *new_mem); /** * ttm_bo_free_old_node * * @bo: A pointer to a struct ttm_buffer_object. * * Utility function to free an old placement after a successful move. */ void ttm_bo_free_old_node(struct ttm_buffer_object *bo); /** * ttm_bo_move_accel_cleanup. * * @bo: A pointer to a struct ttm_buffer_object. * @fence: A fence object that signals when moving is complete. * @evict: This is an evict move. Don't return until the buffer is idle. * @new_mem: struct ttm_mem_reg indicating where to move. * * Accelerated move function to be called when an accelerated move * has been scheduled. The function will create a new temporary buffer object * representing the old placement, and put the sync object on both buffer * objects. After that the newly created buffer object is unref'd to be * destroyed when the move is complete. This will help pipeline * buffer moves. */ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo, struct dma_fence *fence, bool evict, struct ttm_mem_reg *new_mem); /** * ttm_bo_pipeline_move. * * @bo: A pointer to a struct ttm_buffer_object. * @fence: A fence object that signals when moving is complete. * @evict: This is an evict move. Don't return until the buffer is idle. * @new_mem: struct ttm_mem_reg indicating where to move. * * Function for pipelining accelerated moves. Either free the memory * immediately or hang it on a temporary buffer object. */ int ttm_bo_pipeline_move(struct ttm_buffer_object *bo, struct dma_fence *fence, bool evict, struct ttm_mem_reg *new_mem); /** * ttm_io_prot * * @c_state: Caching state. * @tmp: Page protection flag for a normal, cached mapping. * * Utility function that returns the pgprot_t that should be used for * setting up a PTE with the caching model indicated by @c_state. */ pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp); extern const struct ttm_mem_type_manager_func ttm_bo_manager_func; #if IS_ENABLED(CONFIG_AGP) #include /** * ttm_agp_tt_create * * @bdev: Pointer to a struct ttm_bo_device. * @bridge: The agp bridge this device is sitting on. * @size: Size of the data needed backing. * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags. * @dummy_read_page: See struct ttm_bo_device. * * * Create a TTM backend that uses the indicated AGP bridge as an aperture * for TT memory. This function uses the linux agpgart interface to * bind and unbind memory backing a ttm_tt. */ struct ttm_tt *ttm_agp_tt_create(struct ttm_bo_device *bdev, struct agp_bridge_data *bridge, unsigned long size, uint32_t page_flags, struct page *dummy_read_page); int ttm_agp_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx); void ttm_agp_tt_unpopulate(struct ttm_tt *ttm); #endif #endif