path: root/include/drm/ttm/ttm_bo_driver.h

/**************************************************************************
 *
 * 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
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 * The above copyright notice and this permission notice (including the
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */
#ifndef _TTM_BO_DRIVER_H_
#define _TTM_BO_DRIVER_H_

#include <drm/drm_mm.h>
#include <drm/drm_vma_manager.h>
#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/spinlock.h>
#include <linux/dma-resv.h>

#include "ttm_bo_api.h"
#include "ttm_memory.h"
#include "ttm_module.h"
#include "ttm_placement.h"
#include "ttm_tt.h"

/**
 * struct ttm_bo_driver
 *
 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
 * @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
	 *
	 * @bo: The buffer object to create the ttm for.
	 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
	 *
	 * 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_buffer_object *bo,
					uint32_t page_flags);

	/**
	 * 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_bo_device *bdev,
			       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_bo_device *bdev, struct ttm_tt *ttm);

	/**
	 * ttm_tt_bind
	 *
	 * @bdev: Pointer to a ttm device
	 * @ttm: Pointer to a struct ttm_tt.
	 * @bo_mem: Pointer to a struct ttm_resource 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 (*ttm_tt_bind)(struct ttm_bo_device *bdev, struct ttm_tt *ttm, struct ttm_resource *bo_mem);

	/**
	 * ttm_tt_unbind
	 *
	 * @bdev: Pointer to a ttm device
	 * @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.
	 */
	void (*ttm_tt_unbind)(struct ttm_bo_device *bdev, struct ttm_tt *ttm);

	/**
	 * ttm_tt_destroy
	 *
	 * @bdev: Pointer to a ttm device
	 * @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 (*ttm_tt_destroy)(struct ttm_bo_device *bdev, struct ttm_tt *ttm);

	/**
	 * 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_resource *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_resource *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_resource *mem);
	void (*io_mem_free)(struct ttm_bo_device *bdev,
			    struct ttm_resource *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_driver member del_from_lru_notify
	 *
	 * @bo: the buffer object deleted from lru
	 *
	 * notify driver that a BO was deleted from LRU.
	 */
	void (*del_from_lru_notify)(struct ttm_buffer_object *bo);

	/**
	 * Notify the driver that we're about to release a BO
	 *
	 * @bo: BO that is about to be released
	 *
	 * Gives the driver a chance to do any cleanup, including
	 * adding fences that may force a delayed delete
	 */
	void (*release_notify)(struct ttm_buffer_object *bo);
};

/**
 * struct ttm_bo_global - Buffer object driver global data.
 *
 * @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.
 */

extern struct ttm_bo_global {

	/**
	 * Constant after init.
	 */

	struct kobject kobj;
	struct page *dummy_read_page;
	spinlock_t lru_lock;

	/**
	 * Protected by ttm_global_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;
} ttm_bo_glob;


#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 resource_managers.
 * @vma_manager: Address space manager (pointer)
 * 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.
 * @no_retry: Don't retry allocation if it fails
 *
 */

struct ttm_bo_device {

	/*
	 * Constant after bo device init / atomic.
	 */
	struct list_head device_list;
	struct ttm_bo_driver *driver;
	/*
	 * access via ttm_manager_type.
	 */
	struct ttm_resource_manager sysman;
	struct ttm_resource_manager *man_drv[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;

	bool no_retry;
};

static inline struct ttm_resource_manager *ttm_manager_type(struct