/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/**************************************************************************
*
* Copyright (c) 2007-2009 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 <thellstrom-at-vmware-dot-com>
*/
#include <linux/vmalloc.h>
#include <drm/ttm/ttm_bo.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_tt.h>
#include <drm/drm_cache.h>
struct ttm_transfer_obj {
struct ttm_buffer_object base;
struct ttm_buffer_object *bo;
};
int ttm_mem_io_reserve(struct ttm_device *bdev,
struct ttm_resource *mem)
{
if (mem->bus.offset || mem->bus.addr)
return 0;
mem->bus.is_iomem = false;
if (!bdev->funcs->io_mem_reserve)
return 0;
return bdev->funcs->io_mem_reserve(bdev, mem);
}
void ttm_mem_io_free(struct ttm_device *bdev,
struct ttm_resource *mem)
{
if (!mem)
return;
if (!mem->bus.offset && !mem->bus.addr)
return;
if (bdev->funcs->io_mem_free)
bdev->funcs->io_mem_free(bdev, mem);
mem->bus.offset = 0;
mem->bus.addr = NULL;
}
/**
* ttm_move_memcpy - Helper to perform a memcpy ttm move operation.
* @clear: Whether to clear rather than copy.
* @num_pages: Number of pages of the operation.
* @dst_iter: A struct ttm_kmap_iter representing the destination resource.
* @src_iter: A struct ttm_kmap_iter representing the source resource.
*
* This function is intended to be able to move out async under a
* dma-fence if desired.
*/
void ttm_move_memcpy(bool clear,
u32 num_pages,
struct ttm_kmap_iter *dst_iter,
struct ttm_kmap_iter *src_iter)
{
const struct ttm_kmap_iter_ops *dst_ops = dst_iter->ops;
const struct ttm_kmap_iter_ops *src_ops = src_iter->ops;
struct iosys_map src_map, dst_map;
pgoff_t i;
/* Single TTM move. NOP */
if (dst_ops->maps_tt && src_ops->maps_tt)
return;
/* Don't move nonexistent data. Clear destination instead. */
if (clear) {
for (i = 0; i < num_pages; ++i) {
dst_ops->map_local(dst_iter, &dst_map, i);
if (dst_map.is_iomem)
memset_io(dst_map.vaddr_iomem, 0, PAGE_SIZE);
else
memset(dst_map.vaddr, 0, PAGE_SIZE);
if (dst_ops->unmap_local)
dst_ops->unmap_local(dst_iter, &dst_map);
}
return;
}
for (i = 0; i < num_pages; ++i) {
dst_ops->map_local(dst_iter, &dst_map, i);
src_ops->map_local(src_iter, &src_map, i);
drm_memcpy_from_wc(&dst_map, &src_map, PAGE_SIZE);
if (src_ops->unmap_local)
src_ops->unmap_local(src_iter, &src_map);
if (dst_ops->unmap_local)
dst_ops->unmap_local(dst_iter, &dst_map);
}
}
EXPORT_SYMBOL(ttm_move_memcpy);
/**
* ttm_bo_move_memcpy
*
* @bo: A pointer to a struct ttm_buffer_object.
* @ctx: operation context
* @dst_mem: struct ttm_resource 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_resource *dst_mem)
{
struct ttm_device *bdev = bo->bdev;
struct ttm_resource_manager *dst_man =
ttm_manager_type(bo->bdev, dst_mem->mem_type);
struct ttm_tt *ttm = bo->ttm;
struct ttm_resource *src_mem = bo->resource;
struct ttm_resource_manager *src_man;
union {
struct ttm_kmap_iter_tt tt;
struct ttm_kmap_iter_linear_io io;
} _dst_iter, _src_iter;
struct ttm_kmap_iter *dst_iter, *src_iter;
bool clear;
int ret = 0;
if (WARN_ON(!src_mem))
return -EINVAL;
src_man = ttm_manager_type(bdev, src_mem->mem_type);
if (ttm && ((ttm->page_flags & TTM_TT_FLAG_SWAPPED) ||
dst_man->use_tt)) {
ret = ttm_tt_populate(bdev, ttm, ctx);
if (ret)
return ret;
}
dst_iter = ttm_kmap_iter_linear_io_init(&_dst_iter.io, bdev, dst_mem);
if (PTR_ERR(dst_iter) == -EINVAL && dst_man->use_tt)
dst_iter = ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm);
if (IS_ERR(dst_iter))
return PTR_ERR(dst_iter);
src_iter = ttm_kmap_iter_linear_io_init(&_src_iter.io, bdev, src_mem);
if (PTR_ERR(src_iter) == -EINVAL && src_man->use_tt)
src_iter = ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm);
if (IS_ERR(src_iter)) {
ret = PTR_ERR(src_iter);
goto out_src_iter;
}
clear = src_iter->ops->maps_tt && (!ttm || !ttm_tt_is_populated(ttm));
if (!(clear && ttm && !(ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC)))
ttm_move_memcpy(clear, PFN_UP(dst_mem->size), dst_iter, src_iter);
if (!src_iter->ops->maps_tt)
ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, src_mem);
ttm_bo_move_sync_cleanup(bo, dst_mem);
out_src_iter:
if (!dst_iter->ops->maps_tt)
ttm_kmap_iter_linear_io_fini(&_dst_iter.io, bdev, dst_mem);
return ret;
}
EXPORT_SYMBOL(ttm_bo_move_memcpy);
static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
{
struct ttm_transfer_obj *fbo;
fbo = container_of(bo, struct ttm_transfer_obj, base);
dma_resv_fini(&fbo->base.base._resv);
ttm_bo_put(fbo->bo);
kfree(fbo);
}
/**
* ttm_buffer_object_transfer
*
* @bo: A pointer to a struct ttm_buffer_object.
* @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
* holding the data of @bo with the old placement.
*
* This is a utility function that may be called after an accelerated move
* has been scheduled. A new buffer object is created as a placeholder for
* the old data while it's being copied. When that buffer object is idle,
* it can be destroyed, releasing the space of the old placement.
* Returns:
* !0: Failure.
*/
static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
struct ttm_buffer_object **new_obj)
{
struct ttm_transfer_obj *fbo;
int ret;
fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
if (!fbo)
return -ENOMEM;
fbo->base = *bo;
/**
* Fix up members that we shouldn't copy directly:
* TODO: Explicit member copy would probably be better here.
*/
atomic_inc(&ttm_glob.bo_count);
drm_vma_node_reset(&fbo->base.base.vma_node);
kref_init(&fbo->base.kref);
fbo->base.destroy = &ttm_transfered_destroy;
fbo->base.pin_count = 0;
if (bo->type != ttm_bo_type_sg)
fbo->base.base.resv = &fbo->base.base._resv;
dma_resv_init(&fbo->base.base._resv);
fbo->base.base.dev = NULL;
ret = dma_resv_trylock(&fbo->base.base._resv);
WARN_ON(!ret);
if (fbo->base.resource) {
ttm_resource_set_bo(fbo->base.resource, &fbo->base);
bo->resource = NULL;
ttm_bo_set_bulk_move(&fbo->base, NULL);
} else {
fbo->base.bulk_move = NULL;
}
ret = dma_resv_reserve_fences(&fbo->base.base._resv, 1);
if (ret) {
kfree(fbo);
return ret;
}
ttm_bo_get(bo);
fbo->bo = bo;
ttm_bo_move_to_lru_tail_unlocked(&fbo->base);
*new_obj = &fbo->base;
return 0;
}
/**
* ttm_io_prot
*
* @bo: ttm buffer object
* @res: ttm resource object
* @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(struct ttm_buffer_object *bo, struct ttm_resource *res,
pgprot_t tmp)
{
struct ttm_resource_manager *man;
enum ttm_caching caching;
man = ttm_manager_type(bo->bdev, res->mem_type);
if (man->use_tt) {
caching = bo->ttm->caching;
if (bo->ttm->page_flags & TTM_TT_FLAG_DECRYPTED)
tmp = pgprot_decrypted(tmp);
} else {
caching = res->bus.caching;
}
return ttm_prot_from_caching(caching, tmp);
}
EXPORT_SYMBOL(ttm_io_prot);
static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
unsigned long offset,
unsigned long size,
struct ttm_bo_kmap_obj *map)
{
struct ttm_resource *mem = bo->resource;
if (bo->resource->bus.addr) {
map->bo_kmap_type = ttm_bo_map_premapped;
map->virtual = ((u8 *)bo->resource->bus.addr) + offset;
} else {
resource_size_t res = bo->resource->bus.offset + offset;
map->bo_kmap_type = ttm_bo_map_iomap;
if (mem->bus.caching == ttm_write_combined)
map->virtual = ioremap_wc(res, size);
#ifdef CONFIG_X86
else if (mem->bus.caching == ttm_cached)
map->virtual = ioremap_cache(res, size);
#endif
else
map->virtual = ioremap(res, size);
}
return (!map->virtual) ? -ENOMEM : 0;
}
static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
unsigned long start_page,
unsigned long num_pages,
struct ttm_bo_kmap_obj *map)
{
struct ttm_resource *mem = bo->resource;
struct ttm_operation_ctx ctx = {
.interruptible = false,
.no_wait_gpu = false
};
struct ttm_tt *ttm = bo->ttm;
struct ttm_resource_manager *man =
ttm_manager_type(bo->bdev, bo->resource->mem_type);
pgprot_t prot;
int ret;
BUG_ON(!ttm);
ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
if (ret)
return ret;
if (num_pages == 1 && ttm->caching == ttm_cached &&
!(man->use_tt && (ttm->page_flags & TTM_TT_FLAG_DECRYPTED))) {
/*
* We're mapping a single page, and the desired
* page protection is consistent with the bo.
*/
map->bo_kmap_type = ttm_bo_map_kmap;
map->page = ttm->pages[start_page];
map->virtual = kmap(map->page);
} else {
/*
* We need to use vmap to get the desired page protection
* or to make the buffer object look contiguous.
*/
prot = ttm_io_prot(bo, mem, PAGE_KERNEL);
map->bo_kmap_type = ttm_bo_map_vmap;
map->virtual = vmap(ttm->pages + start_page, num_pages,
0, prot);
}
return (!map->virtual) ? -ENOMEM : 0;
}
/**
* ttm_bo_kmap
*
* @bo: The buffer object.
* @start_page: The first page to map.
* @num_pages: Number of pages to map.
* @map: pointer to a struct ttm_bo_kmap_obj representing the map.
*
* Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
* data in the buffer object. The ttm_kmap_obj_virtual function can then be
* used to obtain a virtual address to the data.
*
* Returns
* -ENOMEM: Out of memory.
* -EINVAL: Invalid range.
*/
int ttm_bo_kmap(struct ttm_buffer_object *bo,
unsigned long start_page, unsigned long num_pages,
struct ttm_bo_kmap_obj *map)
{
unsigned long offset, size;
int ret;
map->virtual = NULL;
map->bo = bo;
if (num_pages > PFN_UP(bo->resource->size))
return -EINVAL;
if ((start_page + num_pages) > PFN_UP(bo->resource->size))
return -EINVAL;
ret = ttm_mem_io_reserve(bo->bdev, bo->resource);
if (ret)
return ret;
if (!bo->resource->bus.is_iomem) {
return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
} else {
offset = start_page << PAGE_SHIFT;
size = num_pages << PAGE_SHIFT;
return ttm_bo_ioremap(bo, offset, size, map);
}
}
EXPORT_SYMBOL(ttm_bo_kmap);
/**
* ttm_bo_kunmap
*
* @map: Object describing the map to unmap.
*
* Unmaps a kernel map set up by ttm_bo_kmap.
*/
void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
{
if (!map->virtual)
return;
switch (map->bo_kmap_type) {
case ttm_bo_map_iomap:
iounmap(map->virtual);
break;
case ttm_bo_map_vmap:
vunmap(map->virtual);
break;
case ttm_bo_map_kmap:
kunmap(map->page);
break;
case ttm_bo_map_premapped:
break;
default:
BUG();
}
ttm_mem_io_free(map->bo->bdev, map->bo->resource);
map->virtual = NULL;
map->page = NULL;
}
EXPORT_SYMBOL(ttm_bo_kunmap);
/**
* ttm_bo_vmap
*
* @bo: The buffer object.
* @map: pointer to a struct iosys_map representing the map.
*
* Sets up a kernel virtual mapping, using ioremap or vmap to the
* data in the buffer object. The parameter @map returns the virtual
* address as struct iosys_map. Unmap the buffer with ttm_bo_vunmap().
*
* Returns
* -ENOMEM: Out of memory.
* -EINVAL: Invalid range.
*/
int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map)
{
struct ttm_resource *mem = bo->resource;
int ret;
dma_resv_assert_held(bo->base.resv);
ret = ttm_mem_io_reserve(bo->bdev, mem);
if (ret)
return ret;
if (mem->bus.is_iomem) {
void __iomem *vaddr_iomem;
if (mem->bus.addr)
vaddr_iomem = (void __iomem *)mem->bus.addr;
else if (mem->bus.caching == ttm_write_combined)
vaddr_iomem = ioremap_wc(mem->bus.offset,
bo->base.size);
#ifdef CONFIG_X86
else if (mem->bus.caching == ttm_cached)
vaddr_iomem = ioremap_cache(mem->bus.offset,
bo->base.size);
#endif
else
vaddr_iomem = ioremap(mem->bus.offset, bo->base.size);
if (!vaddr_iomem)
return -ENOMEM;
iosys_map_set_vaddr_iomem(map, vaddr_iomem);
} else {
struct ttm_operation_ctx ctx = {
.interruptible = false,
.no_wait_gpu = false
};
struct ttm_tt *ttm = bo->ttm;
pgprot_t prot;
void *vaddr;
ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
if (ret)
return ret;
/*
* We need to use vmap to get the desired page protection
* or to make the buffer object look contiguous.
*/
prot = ttm_io_prot(bo, mem, PAGE_KERNEL);
vaddr = vmap(ttm->pages, ttm->num_pages, 0, prot);
if (!vaddr)
return -ENOMEM;
iosys_map_set_vaddr(map, vaddr);
}
return 0;
}
EXPORT_SYMBOL(ttm_bo_vmap);
/**
* ttm_bo_vunmap
*
* @bo: The buffer object.
* @map: Object describing the map to unmap.
*
* Unmaps a kernel map set up by ttm_bo_vmap().
*/
void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map)
{
struct ttm_resource *mem = bo->resource;
dma_resv_assert_held(bo->base.resv);
if (iosys_map_is_null(map))
return;
if (!map->is_iomem)
vunmap(map->vaddr);
else if (!mem->bus.addr)
iounmap(map->vaddr_iomem);
iosys_map_clear(map);
ttm_mem_io_free(bo->bdev, bo->resource);
}
EXPORT_SYMBOL(ttm_bo_vunmap);
static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,
bool dst_use_tt)
{
long ret;
ret = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
false, 15 * HZ);
if (ret == 0)
return -EBUSY;
if (ret < 0)
return ret;
if (!dst_use_tt)
ttm_bo_tt_destroy(bo);
ttm_resource_free(bo, &bo->resource);
return 0;
}
static int ttm_bo_move_to_ghost(struct ttm_buffer_object *bo,
struct dma_fence *fence,
bool dst_use_tt)
{
struct ttm_buffer_object *ghost_obj;
int ret;
/**
* This should help pipeline ordinary buffer moves.
*
* Hang old buffer memory on a new buffer object,
* and leave it to be released when the GPU
* operation has completed.
*/
ret = ttm_buffer_object_transfer(bo, &ghost_obj);
if (ret)
return ret;
dma_resv_add_fence(&ghost_obj->base._resv, fence,
DMA_RESV_USAGE_KERNEL);
/**
* If we're not moving to fixed memory, the TTM object
* needs to stay alive. Otherwhise hang it on the ghost
* bo to be unbound and destroyed.
*/
if (dst_use_tt)
ghost_obj->ttm = NULL;
else
bo->ttm = NULL;
dma_resv_unlock(&ghost_obj->base._resv);
ttm_bo_put(ghost_obj);
return 0;
}
static void ttm_bo_move_pipeline_evict(struct ttm_buffer_object *bo,
struct dma_fence *fence)
{
struct ttm_device *bdev = bo->bdev;
struct ttm_resource_manager *from;
from = ttm_manager_type(bdev, bo->resource->mem_type);
/**
* BO doesn't have a TTM we need to bind/unbind. Just remember
* this eviction and free up the allocation
*/
spin_lock(&from->move_lock);
if (!from->move || dma_fence_is_later(fence, from->move)) {
dma_fence_put(from->move);
from->move = dma_fence_get(fence);
}
spin_unlock(&from->move_lock);
ttm_resource_free(bo, &bo->resource);
}
/**
* ttm_bo_move_accel_cleanup - cleanup helper for hw copies
*
* @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.
* @pipeline: evictions are to be pipelined.
* @new_mem: struct ttm_resource 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,
bool pipeline,
struct ttm_resource *new_mem)
{
struct ttm_device *bdev = bo->bdev;
struct ttm_resource_manager *from = ttm_manager_type(bdev, bo->resource->mem_type);
struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
int ret = 0;
dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL);
if (!evict)
ret = ttm_bo_move_to_ghost(bo, fence, man->use_tt);
else if (!from->use_tt && pipeline)
ttm_bo_move_pipeline_evict(bo, fence);
else
ret = ttm_bo_wait_free_node(bo, man->use_tt);
if (ret)
return ret;
ttm_bo_assign_mem(bo, new_mem);
return 0;
}
EXPORT_SYMBOL(ttm_bo_move_accel_cleanup);
/**
* ttm_bo_move_sync_cleanup - cleanup by waiting for the move to finish
*
* @bo: A pointer to a struct ttm_buffer_object.
* @new_mem: struct ttm_resource indicating where to move.
*
* Special case of ttm_bo_move_accel_cleanup where the bo is guaranteed
* by the caller to be idle. Typically used after memcpy buffer moves.
*/
void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo,
struct ttm_resource *new_mem)
{
struct ttm_device *bdev = bo->bdev;
struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
int ret;
ret = ttm_bo_wait_free_node(bo, man->use_tt);
if (WARN_ON(ret))
return;
ttm_bo_assign_mem(bo, new_mem);
}
EXPORT_SYMBOL(ttm_bo_move_sync_cleanup);
/**
* ttm_bo_pipeline_gutting - purge the contents of a bo
* @bo: The buffer object
*
* Purge the contents of a bo, async if the bo is not idle.
* After a successful call, the bo is left unpopulated in
* system placement. The function may wait uninterruptible
* for idle on OOM.
*
* Return: 0 if successful, negative error code on failure.
*/
int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
{
struct ttm_buffer_object *ghost;
struct ttm_tt *ttm;
int ret;
/* If already idle, no need for ghost object dance. */
if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP)) {
if (!bo->ttm) {
/* See comment below about clearing. */
ret = ttm_tt_create(bo, true);
if (ret)
return ret;
} else {
ttm_tt_unpopulate(bo->bdev, bo->ttm);
if (bo->type == ttm_bo_type_device)
ttm_tt_mark_for_clear(bo->ttm);
}
ttm_resource_free(bo, &bo->resource);
return 0;
}
/*
* We need an unpopulated ttm_tt after giving our current one,
* if any, to the ghost object. And we can't afford to fail
* creating one *after* the operation. If the bo subsequently gets
* resurrected, make sure it's cleared (if ttm_bo_type_device)
* to avoid leaking sensitive information to user-space.
*/
ttm = bo->ttm;
bo->ttm = NULL;
ret = ttm_tt_create(bo, true);
swap(bo->ttm, ttm);
if (ret)
return ret;
ret = ttm_buffer_object_transfer(bo, &ghost);
if (ret)
goto error_destroy_tt;
ret = dma_resv_copy_fences(&ghost->base._resv, bo->base.resv);
/* Last resort, wait for the BO to be idle when we are OOM */
if (ret) {
dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
false, MAX_SCHEDULE_TIMEOUT);
}
dma_resv_unlock(&ghost->base._resv);
ttm_bo_put(ghost);
bo->ttm = ttm;
return 0;
error_destroy_tt:
ttm_tt_destroy(bo->bdev, ttm);
return ret;
}
static bool ttm_lru_walk_trylock(struct ttm_lru_walk *walk,
struct ttm_buffer_object *bo,
bool *needs_unlock)
{
struct ttm_operation_ctx *ctx = walk->ctx;
*needs_unlock = false;
if (dma_resv_trylock(bo->base.resv)) {
*needs_unlock = true;
return true;
}
if (bo->base.resv == ctx->resv && ctx->allow_res_evict) {
dma_resv_assert_held(bo->base.resv);
return true;
}
return false;
}
static int ttm_lru_walk_ticketlock(struct ttm_lru_walk *walk,
struct ttm_buffer_object *bo,
bool *needs_unlock)
{
struct dma_resv *resv = bo->base.resv;
int ret;
if (walk->ctx->interruptible)
ret = dma_resv_lock_interruptible(resv, walk->ticket);
else
ret = dma_resv_lock(resv, walk->ticket);
if (!ret) {
*needs_unlock = true;
/*
* Only a single ticketlock per loop. Ticketlocks are prone
* to return -EDEADLK causing the eviction to fail, so
* after waiting for the ticketlock, revert back to
* trylocking for this walk.
*/
walk->ticket = NULL;
} else if (ret == -EDEADLK) {
/* Caller needs to exit the ww transaction. */
ret = -ENOSPC;
}
return ret;
}
static void ttm_lru_walk_unlock(struct ttm_buffer_object *bo, bool locked)
{
if (locked)
dma_resv_unlock(bo->base.resv);
}
/**
* ttm_lru_walk_for_evict() - Perform a LRU list walk, with actions taken on
* valid items.
* @walk: describe the walks and actions taken
* @bdev: The TTM device.
* @man: The struct ttm_resource manager whose LRU lists we're walking.
* @target: The end condition for the walk.
*
* The LRU lists of @man are walk, and for each struct ttm_resource encountered,
* the corresponding ttm_buffer_object is locked and taken a reference on, and
* the LRU lock is dropped. the LRU lock may be dropped before locking and, in
* that case, it's verified that the item actually remains on the LRU list after
* the lock, and that the buffer object didn't switch resource in between.
*
* With a locked object, the actions indicated by @walk->process_bo are
* performed, and after that, the bo is unlocked, the refcount dropped and the
* next struct ttm_resource is processed. Here, the walker relies on
* TTM's restartable LRU list implementation.
*
* Typically @walk->process_bo() would return the number of pages evicted,
* swapped or shrunken, so that when the total exceeds @target, or when the
* LRU list has been walked in full, iteration is terminated. It's also terminated
* on error. Note that the definition of @target is done by the caller, it
* could have a different meaning than the number of pages.
*
* Note that the way dma_resv individualization is done, locking needs to be done
* either with the LRU lock held (trylocking only) or with a reference on the
* object.
*
* Return: The progress made towards target or negative error code on error.
*/
s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
struct ttm_resource_manager *man, s64 target)
{
struct ttm_resource_cursor cursor;
struct ttm_resource *res;
s64 progress = 0;
s64 lret;
spin_lock(&bdev->lru_lock);
ttm_resource_manager_for_each_res(man, &cursor, res) {
struct ttm_buffer_object *bo = res->bo;
bool bo_needs_unlock = false;
bool bo_locked = false;
int mem_type;
/*
* Attempt a trylock before taking a reference on the bo,
* since if we do it the other way around, and the trylock fails,
* we need to drop the lru lock to put the bo.
*/
if (ttm_lru_walk_trylock(walk, bo, &bo_needs_unlock))
bo_locked = true;
else if (!walk->ticket || walk->ctx->no_wait_gpu ||
walk->trylock_only)
continue;
if (!ttm_bo_get_unless_zero(bo)) {
ttm_lru_walk_unlock(bo, bo_needs_unlock);
continue;
}
mem_type = res->mem_type;
spin_unlock(&bdev->lru_lock);
lret = 0;
if (!bo_locked)
lret = ttm_lru_walk_ticketlock(walk, bo, &bo_needs_unlock);
/*
* Note that in between the release of the lru lock and the
* ticketlock, the bo may have switched resource,
* and also memory type, since the resource may have been
* freed and allocated again with a different memory type.
* In that case, just skip it.
*/
if (!lret && bo->resource && bo->resource->mem_type == mem_type)
lret = walk->ops->process_bo(walk, bo);
ttm_lru_walk_unlock(bo, bo_needs_unlock);
ttm_bo_put(bo);
if (lret == -EBUSY || lret == -EALREADY)
lret = 0;
progress = (lret < 0) ? lret : progress + lret;
spin_lock(&bdev->lru_lock);
if (progress < 0 || progress >= target)
break;
}
ttm_resource_cursor_fini(&cursor);
spin_unlock(&bdev->lru_lock);
return progress;
}
Codebase Browser
linux