Subversion Repositories Kolibri OS

/**************************************************************************

 *

 * 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 "ttm/ttm_bo_api.h"

#include "ttm/ttm_memory.h"

#include "ttm/ttm_module.h"

#include "drm_mm.h"

#include "linux/spinlock.h"

struct ttm_backend;

struct ttm_backend_func {

	/**

	 * struct ttm_backend_func member populate

	 *

	 * @backend: Pointer to a struct ttm_backend.

	 * @num_pages: Number of pages to populate.

	 * @pages: Array of pointers to ttm pages.

	 * @dummy_read_page: Page to be used instead of NULL pages in the

	 * array @pages.

	 *

	 * Populate the backend with ttm pages. Depending on the backend,

	 * it may or may not copy the @pages array.

	 */

	int (*populate) (struct ttm_backend *backend,

			 unsigned long num_pages, struct page **pages,

			 struct page *dummy_read_page,

			 dma_addr_t *dma_addrs);

	/**

	 * struct ttm_backend_func member clear

	 *

	 * @backend: Pointer to a struct ttm_backend.

	 *

	 * This is an "unpopulate" function. Release all resources

	 * allocated with populate.

	 */

	void (*clear) (struct ttm_backend *backend);

	/**

	 * struct ttm_backend_func member bind

	 *

	 * @backend: Pointer to a struct ttm_backend.

	 * @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_backend *backend, struct ttm_mem_reg *bo_mem);

	/**

	 * struct ttm_backend_func member unbind

	 *

	 * @backend: Pointer to a struct ttm_backend.

	 *

	 * Unbind previously bound backend pages. This function should be

	 * able to handle differences between aperture- and system page sizes.

	 */

	int (*unbind) (struct ttm_backend *backend);

	/**

	 * struct ttm_backend_func member destroy

	 *

	 * @backend: Pointer to a struct ttm_backend.

	 *

	 * Destroy the backend.

	 */

	void (*destroy) (struct ttm_backend *backend);

};

/**

 * struct ttm_backend

 *

 * @bdev: Pointer to a struct ttm_bo_device.

 * @flags: For driver use.

 * @func: Pointer to a struct ttm_backend_func that describes

 * the backend methods.

 *

 */

struct ttm_backend {

	struct ttm_bo_device *bdev;

	uint32_t flags;

	struct ttm_backend_func *func;

};

#define TTM_PAGE_FLAG_USER            (1 << 1)

#define TTM_PAGE_FLAG_USER_DIRTY      (1 << 2)

#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)

enum ttm_caching_state {

	tt_uncached,

	tt_wc,

	tt_cached

};

/**

 * struct ttm_tt

 *

 * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL

 * pointer.

 * @pages: Array of pages backing the data.

 * @first_himem_page: Himem pages are put last in the page array, which

 * enables us to run caching attribute changes on only the first part

 * of the page array containing lomem pages. This is the index of the

 * first himem page.

 * @last_lomem_page: Index of the last lomem page in the page array.

 * @num_pages: Number of pages in the page array.

 * @bdev: Pointer to the current struct ttm_bo_device.

 * @be: Pointer to the ttm backend.

 * @tsk: The task for user ttm.

 * @start: virtual address for user ttm.

 * @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.

 * @dma_address: The DMA (bus) addresses of the pages (if TTM_PAGE_FLAG_DMA32)

 *

 * 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 page *dummy_read_page;

	struct page **pages;

	long first_himem_page;

	long last_lomem_page;

	uint32_t page_flags;

	unsigned long num_pages;

	struct ttm_bo_global *glob;

	struct ttm_backend *be;

	struct task_struct *tsk;

	unsigned long start;

	struct file *swap_storage;

	enum ttm_caching_state caching_state;

	enum {

		tt_bound,

		tt_unbound,

		tt_unpopulated,

	} state;

	dma_addr_t *dma_address;

};

#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

 *

 * @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

 * static information. bdev::driver::io_mem_free is never used.

 * @lru: The lru list for this memory type.

 *

 * 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;

	unsigned long gpu_offset;

	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;

	/*

	 * Protected by @io_reserve_mutex:

	 */

	struct list_head io_reserve_lru;

	/*

	 * Protected by the global->lru_lock.

	 */

	struct list_head lru;

};

/**

 * 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.

 * @sync_obj_signaled: See ttm_fence_api.h

 * @sync_obj_wait: See ttm_fence_api.h

 * @sync_obj_flush: See ttm_fence_api.h

 * @sync_obj_unref: See ttm_fence_api.h

 * @sync_obj_ref: See ttm_fence_api.h

 */

struct ttm_bo_driver {

	/**

	 * struct ttm_bo_driver member create_ttm_backend_entry

	 *

	 * @bdev: The buffer object device.

	 *

	 * Create a driver specific struct ttm_backend.

	 */

	struct ttm_backend *(*create_ttm_backend_entry)

	 (struct ttm_bo_device *bdev);

	/**

	 * 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 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

	 * @interruptible: Use interruptible sleeps if possible when sleeping.

	 * @no_wait: whether this should give up and return -EBUSY

	 * if this move would require sleeping

	 * @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, bool interruptible,

		     bool no_wait, 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);

	/**

	 * In case a driver writer dislikes the TTM fence objects,

	 * the driver writer can replace those with sync objects of

	 * his / her own. If it turns out that no driver writer is

	 * using these. I suggest we remove these hooks and plug in

	 * fences directly. The bo driver needs the following functionality:

	 * See the corresponding functions in the fence object API

	 * documentation.

	 */

	bool (*sync_obj_signaled) (void *sync_obj, void *sync_arg);

	int (*sync_obj_wait) (void *sync_obj, void *sync_arg,

			      bool lazy, bool interruptible);

	int (*sync_obj_flush) (void *sync_obj, void *sync_arg);

	void (*sync_obj_unref) (void **sync_obj);

	void *(*sync_obj_ref) (void *sync_obj);

	/* hook to notify driver about a driver move so it

	 * can do tiling things */

	void (*move_notify)(struct ttm_buffer_object *bo,

			    struct ttm_mem_reg *new_mem);

	/* notify the driver we are taking a fault on this BO

	 * and have reserved it */

	void (*fault_reserve_notify)(struct ttm_buffer_object *bo);

};

/**

 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.

 */

struct ttm_bo_global_ref {

	struct ttm_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.

 * @ttm_bo_extra_size: Extra size (sizeof(struct ttm_buffer_object) excluded)

 * used by a buffer object. This is excluding page arrays and backing pages.

 * @ttm_bo_size: This is @ttm_bo_extra_size + sizeof(struct ttm_buffer_object).

 * @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 ttm_mem_shrink shrink;

	size_t ttm_bo_extra_size;

	size_t ttm_bo_size;

	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;

	/**

	 * Internal protection.

	 */

	atomic_t bo_count;

};

#define TTM_NUM_MEM_TYPES 8

#define TTM_BO_PRIV_FLAG_MOVING  0	/* Buffer object is moving and needs

					   idling before CPU mapping */

#define TTM_BO_PRIV_FLAG_MAX 1

/**

 * 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.

 * @addr_space_mm: Range manager for the device address space.

 * lru_lock: Spinlock that protects the buffer+device lru lists and

 * ddestroy lists.

 * @nice_mode: Try nicely to wait for buffer idle when cleaning a manager.

 * If a GPU lockup has been detected, this is forced to 0.

 * @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;

    rwlock_t vm_lock;

	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];

	/*

	 * Protected by the vm lock.

	 */

//   struct rb_root addr_space_rb;

	struct drm_mm addr_space_mm;

	/*

	 * Protected by the global:lru lock.

	 */

	struct list_head ddestroy;

	/*

	 * Protected by load / firstopen / lastclose /unload sync.

	 */

	bool nice_mode;

    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_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.

 */

extern 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_set_user:

 *

 * @ttm: The struct ttm_tt to populate.

 * @tsk: A struct task_struct for which @start is a valid user-space address.

 * @start: A valid user-space address.

 * @num_pages: Size in pages of the user memory area.

 *

 * Populate a struct ttm_tt with a user-space memory area after first pinning

 * the pages backing it.

 * Returns:

 * !0: Error.

 */

extern int ttm_tt_set_user(struct ttm_tt *ttm,

			   struct task_struct *tsk,

			   unsigned long start, unsigned long num_pages);

/**

 * 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

 */

extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);

/**

 * ttm_tt_populate:

 *

 * @ttm: The struct ttm_tt to contain the backing pages.

 *

 * Add backing pages to all of @ttm

 */

extern int ttm_tt_populate(struct ttm_tt *ttm);

/**

 * ttm_ttm_destroy:

 *

 * @ttm: The struct ttm_tt.

 *

 * Unbind, unpopulate and destroy a struct ttm_tt.

 */

extern void ttm_tt_destroy(struct ttm_tt *ttm);

/**

 * ttm_ttm_unbind:

 *

 * @ttm: The struct ttm_tt.

 *

 * Unbind a struct ttm_tt.

 */

extern void ttm_tt_unbind(struct ttm_tt *ttm);

/**

 * ttm_ttm_destroy:

 *

 * @ttm: The struct ttm_tt.

 * @index: Index of the desired page.

 *

 * Return a pointer to the struct page backing @ttm at page

 * index @index. If the page is unpopulated, one will be allocated to

 * populate that index.

 *

 * Returns:

 * NULL on OOM.

 */

extern struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index);

/**

 * ttm_tt_cache_flush:

 *

 * @pages: An array of pointers to struct page:s to flush.

 * @num_pages: Number of pages to flush.

 *

 * Flush the data of the indicated pages from the cpu caches.

 * This is used when changing caching attributes of the pages from

 * cache-coherent.

 */

extern void ttm_tt_cache_flush(struct page *pages[], unsigned long num_pages);

/**

 * 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.

 */

extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);

extern int ttm_tt_swapout(struct ttm_tt *ttm,

			  struct file *persistant_swap_storage);

/*

 * 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.

 */

extern 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: Don't sleep waiting for space to become available.

 *

 * 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.

 */

extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,

				struct ttm_placement *placement,

				struct ttm_mem_reg *mem,

				bool interruptible, bool no_wait);

/**

 * ttm_bo_wait_for_cpu

 *

 * @bo: Pointer to a struct ttm_buffer_object.

 * @no_wait: Don't sleep while waiting.

 *

 * Wait until a buffer object is no longer sync'ed for CPU access.

 * Returns:

 * -EBUSY: Buffer object was sync'ed for CPU access. (only if no_wait == 1).

 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.

 */

extern int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait);

/**

 * ttm_bo_pci_offset - Get the PCI offset for the buffer object memory.

 *

 * @bo Pointer to a struct ttm_buffer_object.

 * @bus_base On return the base of the PCI region

 * @bus_offset On return the byte offset into the PCI region

 * @bus_size On return the byte size of the buffer object or zero if

 * the buffer object memory is not accessible through a PCI region.

 *

 * Returns:

 * -EINVAL if the buffer object is currently not mappable.

 * 0 otherwise.

 */

extern int ttm_bo_pci_offset(struct ttm_bo_device *bdev,

			     struct ttm_mem_reg *mem,

			     unsigned long *bus_base,

			     unsigned long *bus_offset,

			     unsigned long *bus_size);

extern void ttm_bo_global_release(struct ttm_global_reference *ref);

extern int ttm_bo_global_init(struct ttm_global_reference *ref);

extern 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.

 * @mem_global: A pointer to an initialized struct ttm_mem_global.

 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.

 * @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.

 */

extern int ttm_bo_device_init(struct ttm_bo_device *bdev,

			      struct ttm_bo_global *glob,

			      struct ttm_bo_driver *driver,

			      uint64_t file_page_offset, bool need_dma32);

/**

 * ttm_bo_unmap_virtual

 *

 * @bo: tear down the virtual mappings for this BO

 */

extern void ttm_bo_unmap_virtual(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.

 * @use_sequence: If @bo is already reserved, Only sleep waiting for

 * it to become unreserved if @sequence < (@bo)->sequence.

 *

 * 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

 * occuring:

 * 1) Buffers are reserved with the lru spinlock held. Upon successful

 * reservation they are removed from the lru list. This stops a reserved buffer

 * from being evicted. However the lru spinlock is released between the time

 * a buffer is selected for eviction and the time it is reserved.

 * Therefore a check is made when a buffer is reserved for eviction, that it

 * is still the first buffer in the lru list, before it is removed from the

 * list. @check_lru == 1 forces this check. If it fails, the function returns

 * -EINVAL, and the caller should then choose a new buffer to evict and repeat

 * the procedure.

 * 2) 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_sequence == 1 and @sequence == 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 -EAGAIN. Otherwise it sleeps

 * waiting for the buffer to become unreserved, after which it retries

 * reserving.

 * The caller should, when receiving an -EAGAIN 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:

 * -EAGAIN: 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.

 */

extern int ttm_bo_reserve(struct ttm_buffer_object *bo,

			  bool interruptible,

			  bool no_wait, bool use_sequence, uint32_t sequence);

/**

 * ttm_bo_unreserve

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 *

 * Unreserve a previous reservation of @bo.

 */

extern void ttm_bo_unreserve(struct ttm_buffer_object *bo);

/**

 * ttm_bo_wait_unreserved

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 *

 * Wait for a struct ttm_buffer_object to become unreserved.

 * This is typically used in the execbuf code to relax cpu-usage when

 * a potential deadlock condition backoff.

 */

extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo,

				  bool interruptible);

/**

 * ttm_bo_block_reservation

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 * @interruptible: Use interruptible sleep when waiting.

 * @no_wait: Don't sleep, but rather return -EBUSY.

 *

 * Block reservation for validation by simply reserving the buffer.

 * This is intended for single buffer use only without eviction,

 * and thus needs no deadlock protection.

 *

 * Returns:

 * -EBUSY: If no_wait == 1 and the buffer is already reserved.

 * -ERESTARTSYS: If interruptible == 1 and the process received a signal

 * while sleeping.

 */

extern int ttm_bo_block_reservation(struct ttm_buffer_object *bo,

				    bool interruptible, bool no_wait);

/**

 * ttm_bo_unblock_reservation

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 *

 * Unblocks reservation leaving lru lists untouched.

 */

extern void ttm_bo_unblock_reservation(struct ttm_buffer_object *bo);

/*

 * ttm_bo_util.c

 */

/**

 * ttm_bo_move_ttm

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 * @evict: 1: This is an eviction. Don't try to pipeline.

 * @no_wait: Never sleep, but rather return with -EBUSY.

 * @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.

 */

extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,

			   bool evict, bool no_wait,

			   struct ttm_mem_reg *new_mem);

/**

 * ttm_bo_move_memcpy

 *

 * @bo: A pointer to a struct ttm_buffer_object.

 * @evict: 1: This is an eviction. Don't try to pipeline.

 * @no_wait: Never sleep, but rather return with -EBUSY.

 * @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.

 */

extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,

			      bool evict,

			      bool no_wait, 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.

 */

extern 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.

 * @sync_obj: A sync object that signals when moving is complete.

 * @sync_obj_arg: An argument to pass to the sync object idle / wait

 * functions.

 * @evict: This is an evict move. Don't return until the buffer is idle.

 * @no_wait: Never sleep, but rather return with -EBUSY.

 * @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.

 */

extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,

				     void *sync_obj,

				     void *sync_obj_arg,

				     bool evict, bool no_wait,

				     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.

 */

extern pgprot_t ttm_io_prot(enum ttm_caching_state c_state, pgprot_t tmp);

#if (defined(CONFIG_AGP) || (defined(CONFIG_AGP_MODULE) && defined(MODULE)))

#define TTM_HAS_AGP

#include 

/**

 * ttm_agp_backend_init

 *

 * @bdev: Pointer to a struct ttm_bo_device.

 * @bridge: The agp bridge this device is sitting on.

 *

 * 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.

 */

extern struct ttm_backend *ttm_agp_backend_init(struct ttm_bo_device *bdev,

						struct agp_bridge_data *bridge);

#endif

#endif