Acked-by: Thomas Hellstrom <thellstrom at vmware.com>
On 03/06/2018 10:13 AM, Christian König wrote:
> Hi Michel & Thomas,
>
> any more comments on this? Or can I commit it?
>
> Thanks,
> Christian.
>
> Am 27.02.2018 um 12:49 schrieb Christian König:
>> Let's stop mangling everything in a single header and create one header
>> per object instead.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>  drivers/gpu/drm/ttm/ttm_tt.c   |  6 -
>> Â include/drm/ttm/ttm_bo_driver.h | 237
>> +---------------------------------
>>  include/drm/ttm/ttm_tt.h       | 272
>> ++++++++++++++++++++++++++++++++++++++++
>> Â 3 files changed, 273 insertions(+), 242 deletions(-)
>> Â create mode 100644 include/drm/ttm/ttm_tt.h
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
>> index 0ee3b8f11605..8e0b525cda00 100644
>> --- a/drivers/gpu/drm/ttm/ttm_tt.c
>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
>> @@ -31,17 +31,11 @@
>> Â #define pr_fmt(fmt) "[TTM] " fmt
>> Â Â #include <linux/sched.h>
>> -#include <linux/highmem.h>
>> Â #include <linux/pagemap.h>
>> Â #include <linux/shmem_fs.h>
>> Â #include <linux/file.h>
>> -#include <linux/swap.h>
>> -#include <linux/slab.h>
>> -#include <linux/export.h>
>> Â #include <drm/drm_cache.h>
>> -#include <drm/ttm/ttm_module.h>
>> Â #include <drm/ttm/ttm_bo_driver.h>
>> -#include <drm/ttm/ttm_placement.h>
>> Â #include <drm/ttm/ttm_page_alloc.h>
>> Â #ifdef CONFIG_X86
>> Â #include <asm/set_memory.h>
>> diff --git a/include/drm/ttm/ttm_bo_driver.h
>> b/include/drm/ttm/ttm_bo_driver.h
>> index 4312b5326f0b..f8e2515b401f 100644
>> --- a/include/drm/ttm/ttm_bo_driver.h
>> +++ b/include/drm/ttm/ttm_bo_driver.h
>> @@ -42,111 +42,10 @@
>> Â #include "ttm_memory.h"
>> Â #include "ttm_module.h"
>> Â #include "ttm_placement.h"
>> +#include "ttm_tt.h"
>> Â Â #define TTM_MAX_BO_PRIORITYÂ Â Â 4U
>> Â -struct ttm_backend_func {
>> -Â Â Â /**
>> -Â Â Â Â * struct ttm_backend_func member bind
>> -Â Â Â Â *
>> -Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> -Â Â Â Â * @bo_mem: Pointer to a struct ttm_mem_reg describing the
>> -Â Â Â Â * memory type and location for binding.
>> -Â Â Â Â *
>> -Â Â Â Â * Bind the backend pages into the aperture in the location
>> -Â Â Â Â * indicated by @bo_mem. This function should be able to handle
>> -Â Â Â Â * differences between aperture and system page sizes.
>> -Â Â Â Â */
>> -Â Â Â int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
>> -
>> -Â Â Â /**
>> -Â Â Â Â * struct ttm_backend_func member unbind
>> -Â Â Â Â *
>> -Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> -Â Â Â Â *
>> -Â Â Â Â * Unbind previously bound backend pages. This function should be
>> -Â Â Â Â * able to handle differences between aperture and system page
>> sizes.
>> -Â Â Â Â */
>> -Â Â Â int (*unbind) (struct ttm_tt *ttm);
>> -
>> -Â Â Â /**
>> -Â Â Â Â * struct ttm_backend_func member destroy
>> -Â Â Â Â *
>> -Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> -Â Â Â Â *
>> -Â Â Â Â * Destroy the backend. This will be call back from
>> ttm_tt_destroy so
>> -Â Â Â Â * don't call ttm_tt_destroy from the callback or infinite loop.
>> -Â Â Â Â */
>> -Â Â Â void (*destroy) (struct ttm_tt *ttm);
>> -};
>> -
>> -#define TTM_PAGE_FLAG_WRITEÂ Â Â Â Â Â Â Â Â Â (1 << 3)
>> -#define TTM_PAGE_FLAG_SWAPPEDÂ Â Â Â Â Â Â Â (1 << 4)
>> -#define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
>> -#define TTM_PAGE_FLAG_ZERO_ALLOCÂ Â Â Â Â (1 << 6)
>> -#define TTM_PAGE_FLAG_DMA32Â Â Â Â Â Â Â Â Â Â (1 << 7)
>> -#define TTM_PAGE_FLAG_SGÂ Â Â Â Â Â Â Â Â Â Â Â Â (1 << 8)
>> -#define TTM_PAGE_FLAG_NO_RETRYÂ Â Â Â Â Â Â Â Â (1 << 9)
>> -
>> -enum ttm_caching_state {
>> -Â Â Â tt_uncached,
>> -Â Â Â tt_wc,
>> -Â Â Â 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.
>> - * 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 {
>> -Â Â Â struct ttm_bo_device *bdev;
>> -Â Â Â struct ttm_backend_func *func;
>> -Â Â Â struct page **pages;
>> -Â Â Â uint32_t page_flags;
>> -Â Â Â unsigned long num_pages;
>> -Â Â Â struct sg_table *sg; /* for SG objects via dma-buf */
>> -Â Â Â struct file *swap_storage;
>> -Â Â Â enum ttm_caching_state caching_state;
>> -Â Â Â enum {
>> -Â Â Â Â Â Â Â tt_bound,
>> -Â Â Â Â Â Â Â tt_unbound,
>> -Â Â Â Â Â Â Â tt_unpopulated,
>> -Â Â Â } 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 {
>> -Â Â Â struct ttm_tt ttm;
>> -Â Â Â dma_addr_t *dma_address;
>> -Â Â Â struct list_head pages_list;
>> -};
>> -
>> Â #define TTM_MEMTYPE_FLAG_FIXEDÂ Â Â Â Â Â Â Â (1 << 0)Â Â Â /* Fixed
>> (on-card) PCI memory */
>> Â #define TTM_MEMTYPE_FLAG_MAPPABLEÂ Â Â Â Â (1 << 1)Â Â Â /* Memory
>> mappable */
>> Â #define TTM_MEMTYPE_FLAG_CMAÂ Â Â Â Â Â Â Â Â Â (1 << 3)Â Â Â /* Can't map
>> aperture */
>> @@ -610,117 +509,6 @@ ttm_flag_masked(uint32_t *old, uint32_t new,
>> uint32_t mask)
>> Â Â Â Â Â return *old;
>> Â }
>> Â -/**
>> - * ttm_tt_create
>> - *
>> - * @bo: pointer to a struct ttm_buffer_object
>> - * @zero_alloc: true if allocated pages needs to be zeroed
>> - *
>> - * Make sure we have a TTM structure allocated for the given BO.
>> - * No pages are actually allocated.
>> - */
>> -int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc);
>> -
>> -/**
>> - * 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.
>> - *
>> - * 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,
>> -Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> -int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device
>> *bdev,
>> -Â Â Â Â Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> -
>> -/**
>> - * 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,
>> -Â Â Â Â Â Â Â struct ttm_operation_ctx *ctx);
>> -
>> -/**
>> - * 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_populate - allocate pages for a ttm
>> - *
>> - * @ttm: Pointer to the ttm_tt structure
>> - *
>> - * Calls the driver method to allocate pages for a ttm
>> - */
>> -int ttm_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx);
>> -
>> -/**
>> - * 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);
>> -
>> Â /*
>> Â Â * ttm_bo.c
>> Â Â */
>> @@ -1074,27 +862,4 @@ pgprot_t ttm_io_prot(uint32_t caching_flags,
>> pgprot_t tmp);
>> Â Â extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
>> Â -#if IS_ENABLED(CONFIG_AGP)
>> -#include <linux/agp_backend.h>
>> -
>> -/**
>> - * 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.
>> - *
>> - *
>> - * 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,
>> -Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â struct agp_bridge_data *bridge,
>> -Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> -int ttm_agp_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx
>> *ctx);
>> -void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);
>> -#endif
>> -
>> Â #endif
>> diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
>> new file mode 100644
>> index 000000000000..9c78556b488e
>> --- /dev/null
>> +++ b/include/drm/ttm/ttm_tt.h
>> @@ -0,0 +1,272 @@
>> +/**************************************************************************
>>
>> + *
>> + * 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.
>> + *
>> +
>> **************************************************************************/
>> +#ifndef _TTM_TT_H_
>> +#define _TTM_TT_H_
>> +
>> +#include <linux/types.h>
>> +
>> +struct ttm_tt;
>> +struct ttm_mem_reg;
>> +struct ttm_buffer_object;
>> +struct ttm_operation_ctx;
>> +
>> +#define TTM_PAGE_FLAG_WRITEÂ Â Â Â Â Â Â Â Â Â (1 << 3)
>> +#define TTM_PAGE_FLAG_SWAPPEDÂ Â Â Â Â Â Â Â (1 << 4)
>> +#define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
>> +#define TTM_PAGE_FLAG_ZERO_ALLOCÂ Â Â Â Â (1 << 6)
>> +#define TTM_PAGE_FLAG_DMA32Â Â Â Â Â Â Â Â Â Â (1 << 7)
>> +#define TTM_PAGE_FLAG_SGÂ Â Â Â Â Â Â Â Â Â Â Â Â (1 << 8)
>> +#define TTM_PAGE_FLAG_NO_RETRYÂ Â Â Â Â Â Â Â Â (1 << 9)
>> +
>> +enum ttm_caching_state {
>> +Â Â Â tt_uncached,
>> +Â Â Â tt_wc,
>> +Â Â Â tt_cached
>> +};
>> +
>> +struct ttm_backend_func {
>> +Â Â Â /**
>> +Â Â Â Â * struct ttm_backend_func member bind
>> +Â Â Â Â *
>> +Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> +Â Â Â Â * @bo_mem: Pointer to a struct ttm_mem_reg describing the
>> +Â Â Â Â * memory type and location for binding.
>> +Â Â Â Â *
>> +Â Â Â Â * Bind the backend pages into the aperture in the location
>> +Â Â Â Â * indicated by @bo_mem. This function should be able to handle
>> +Â Â Â Â * differences between aperture and system page sizes.
>> +Â Â Â Â */
>> +Â Â Â int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
>> +
>> +Â Â Â /**
>> +Â Â Â Â * struct ttm_backend_func member unbind
>> +Â Â Â Â *
>> +Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> +Â Â Â Â *
>> +Â Â Â Â * Unbind previously bound backend pages. This function should be
>> +Â Â Â Â * able to handle differences between aperture and system page
>> sizes.
>> +Â Â Â Â */
>> +Â Â Â int (*unbind) (struct ttm_tt *ttm);
>> +
>> +Â Â Â /**
>> +Â Â Â Â * struct ttm_backend_func member destroy
>> +Â Â Â Â *
>> +Â Â Â Â * @ttm: Pointer to a struct ttm_tt.
>> +Â Â Â Â *
>> +Â Â Â Â * Destroy the backend. This will be call back from
>> ttm_tt_destroy so
>> +Â Â Â Â * don't call ttm_tt_destroy from the callback or infinite loop.
>> +Â Â Â Â */
>> +Â Â Â void (*destroy) (struct ttm_tt *ttm);
>> +};
>> +
>> +/**
>> + * struct ttm_tt
>> + *
>> + * @bdev: Pointer to a struct ttm_bo_device.
>> + * @func: Pointer to a struct ttm_backend_func that describes
>> + * the backend methods.
>> + * 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 {
>> +Â Â Â struct ttm_bo_device *bdev;
>> +Â Â Â struct ttm_backend_func *func;
>> +Â Â Â struct page **pages;
>> +Â Â Â uint32_t page_flags;
>> +Â Â Â unsigned long num_pages;
>> +Â Â Â struct sg_table *sg; /* for SG objects via dma-buf */
>> +Â Â Â struct file *swap_storage;
>> +Â Â Â enum ttm_caching_state caching_state;
>> +Â Â Â enum {
>> +Â Â Â Â Â Â Â tt_bound,
>> +Â Â Â Â Â Â Â tt_unbound,
>> +Â Â Â Â Â Â Â tt_unpopulated,
>> +Â Â Â } 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 {
>> +Â Â Â struct ttm_tt ttm;
>> +Â Â Â dma_addr_t *dma_address;
>> +Â Â Â struct list_head pages_list;
>> +};
>> +
>> +/**
>> + * ttm_tt_create
>> + *
>> + * @bo: pointer to a struct ttm_buffer_object
>> + * @zero_alloc: true if allocated pages needs to be zeroed
>> + *
>> + * Make sure we have a TTM structure allocated for the given BO.
>> + * No pages are actually allocated.
>> + */
>> +int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc);
>> +
>> +/**
>> + * 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.
>> + *
>> + * 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,
>> +Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> +int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device
>> *bdev,
>> +Â Â Â Â Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> +
>> +/**
>> + * 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,
>> +Â Â Â Â Â Â Â struct ttm_operation_ctx *ctx);
>> +
>> +/**
>> + * 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_populate - allocate pages for a ttm
>> + *
>> + * @ttm: Pointer to the ttm_tt structure
>> + *
>> + * Calls the driver method to allocate pages for a ttm
>> + */
>> +int ttm_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx);
>> +
>> +/**
>> + * 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);
>> +
>> +#if IS_ENABLED(CONFIG_AGP)
>> +#include <linux/agp_backend.h>
>> +
>> +/**
>> + * 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.
>> + *
>> + *
>> + * 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,
>> +Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â struct agp_bridge_data *bridge,
>> +Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â unsigned long size, uint32_t page_flags);
>> +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
