linux-stable/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
Matthew Auld d22632c83b drm/i915: support forcing the page size with lmem
For some specialised objects we might need something larger than the
regions min_page_size due to some hw restriction, and slightly more
hairy is needing something smaller with the guarantee that such objects
will never be inserted into any GTT, which is the case for the paging
structures.

This also fixes how we setup the BO page_alignment, if we later migrate
the object somewhere else. For example if the placements are {SMEM,
LMEM}, then we might get this wrong. Pushing the min_page_size behaviour
into the manager should fix this.

v2(Thomas): push the default page size behaviour into buddy_man, and let
the user override it with the page-alignment, which looks cleaner

v3: rebase on ttm sys changes

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625103824.558481-1-matthew.auld@intel.com
2021-06-30 13:24:29 +01:00

258 lines
6.7 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2021 Intel Corporation
*/
#include <linux/slab.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include "i915_ttm_buddy_manager.h"
#include "i915_buddy.h"
#include "i915_gem.h"
struct i915_ttm_buddy_manager {
struct ttm_resource_manager manager;
struct i915_buddy_mm mm;
struct list_head reserved;
struct mutex lock;
u64 default_page_size;
};
static struct i915_ttm_buddy_manager *
to_buddy_manager(struct ttm_resource_manager *man)
{
return container_of(man, struct i915_ttm_buddy_manager, manager);
}
static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
struct ttm_buffer_object *bo,
const struct ttm_place *place,
struct ttm_resource **res)
{
struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
struct i915_ttm_buddy_resource *bman_res;
struct i915_buddy_mm *mm = &bman->mm;
unsigned long n_pages;
unsigned int min_order;
u64 min_page_size;
u64 size;
int err;
GEM_BUG_ON(place->fpfn || place->lpfn);
bman_res = kzalloc(sizeof(*bman_res), GFP_KERNEL);
if (!bman_res)
return -ENOMEM;
ttm_resource_init(bo, place, &bman_res->base);
INIT_LIST_HEAD(&bman_res->blocks);
bman_res->mm = mm;
GEM_BUG_ON(!bman_res->base.num_pages);
size = bman_res->base.num_pages << PAGE_SHIFT;
min_page_size = bman->default_page_size;
if (bo->page_alignment)
min_page_size = bo->page_alignment << PAGE_SHIFT;
GEM_BUG_ON(min_page_size < mm->chunk_size);
min_order = ilog2(min_page_size) - ilog2(mm->chunk_size);
if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
size = roundup_pow_of_two(size);
min_order = ilog2(size) - ilog2(mm->chunk_size);
}
if (size > mm->size) {
err = -E2BIG;
goto err_free_res;
}
n_pages = size >> ilog2(mm->chunk_size);
do {
struct i915_buddy_block *block;
unsigned int order;
order = fls(n_pages) - 1;
GEM_BUG_ON(order > mm->max_order);
GEM_BUG_ON(order < min_order);
do {
mutex_lock(&bman->lock);
block = i915_buddy_alloc(mm, order);
mutex_unlock(&bman->lock);
if (!IS_ERR(block))
break;
if (order-- == min_order) {
err = -ENOSPC;
goto err_free_blocks;
}
} while (1);
n_pages -= BIT(order);
list_add_tail(&block->link, &bman_res->blocks);
if (!n_pages)
break;
} while (1);
*res = &bman_res->base;
return 0;
err_free_blocks:
mutex_lock(&bman->lock);
i915_buddy_free_list(mm, &bman_res->blocks);
mutex_unlock(&bman->lock);
err_free_res:
kfree(bman_res);
return err;
}
static void i915_ttm_buddy_man_free(struct ttm_resource_manager *man,
struct ttm_resource *res)
{
struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
mutex_lock(&bman->lock);
i915_buddy_free_list(&bman->mm, &bman_res->blocks);
mutex_unlock(&bman->lock);
kfree(bman_res);
}
static const struct ttm_resource_manager_func i915_ttm_buddy_manager_func = {
.alloc = i915_ttm_buddy_man_alloc,
.free = i915_ttm_buddy_man_free,
};
/**
* i915_ttm_buddy_man_init - Setup buddy allocator based ttm manager
* @bdev: The ttm device
* @type: Memory type we want to manage
* @use_tt: Set use_tt for the manager
* @size: The size in bytes to manage
* @default_page_size: The default minimum page size in bytes for allocations,
* this must be at least as large as @chunk_size, and can be overridden by
* setting the BO page_alignment, to be larger or smaller as needed.
* @chunk_size: The minimum page size in bytes for our allocations i.e
* order-zero
*
* Note that the starting address is assumed to be zero here, since this
* simplifies keeping the property where allocated blocks having natural
* power-of-two alignment. So long as the real starting address is some large
* power-of-two, or naturally start from zero, then this should be fine. Also
* the &i915_ttm_buddy_man_reserve interface can be used to preserve alignment
* if say there is some unusable range from the start of the region. We can
* revisit this in the future and make the interface accept an actual starting
* offset and let it take care of the rest.
*
* Note that if the @size is not aligned to the @chunk_size then we perform the
* required rounding to get the usable size. The final size in pages can be
* taken from &ttm_resource_manager.size.
*
* Return: 0 on success, negative error code on failure.
*/
int i915_ttm_buddy_man_init(struct ttm_device *bdev,
unsigned int type, bool use_tt,
u64 size, u64 default_page_size,
u64 chunk_size)
{
struct ttm_resource_manager *man;
struct i915_ttm_buddy_manager *bman;
int err;
bman = kzalloc(sizeof(*bman), GFP_KERNEL);
if (!bman)
return -ENOMEM;
err = i915_buddy_init(&bman->mm, size, chunk_size);
if (err)
goto err_free_bman;
mutex_init(&bman->lock);
INIT_LIST_HEAD(&bman->reserved);
GEM_BUG_ON(default_page_size < chunk_size);
bman->default_page_size = default_page_size;
man = &bman->manager;
man->use_tt = use_tt;
man->func = &i915_ttm_buddy_manager_func;
ttm_resource_manager_init(man, bman->mm.size >> PAGE_SHIFT);
ttm_resource_manager_set_used(man, true);
ttm_set_driver_manager(bdev, type, man);
return 0;
err_free_bman:
kfree(bman);
return err;
}
/**
* i915_ttm_buddy_man_fini - Destroy the buddy allocator ttm manager
* @bdev: The ttm device
* @type: Memory type we want to manage
*
* Note that if we reserved anything with &i915_ttm_buddy_man_reserve, this will
* also be freed for us here.
*
* Return: 0 on success, negative error code on failure.
*/
int i915_ttm_buddy_man_fini(struct ttm_device *bdev, unsigned int type)
{
struct ttm_resource_manager *man = ttm_manager_type(bdev, type);
struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
struct i915_buddy_mm *mm = &bman->mm;
int ret;
ttm_resource_manager_set_used(man, false);
ret = ttm_resource_manager_evict_all(bdev, man);
if (ret)
return ret;
ttm_set_driver_manager(bdev, type, NULL);
mutex_lock(&bman->lock);
i915_buddy_free_list(mm, &bman->reserved);
i915_buddy_fini(mm);
mutex_unlock(&bman->lock);
ttm_resource_manager_cleanup(man);
kfree(bman);
return 0;
}
/**
* i915_ttm_buddy_man_reserve - Reserve address range
* @man: The buddy allocator ttm manager
* @start: The offset in bytes, where the region start is assumed to be zero
* @size: The size in bytes
*
* Note that the starting address for the region is always assumed to be zero.
*
* Return: 0 on success, negative error code on failure.
*/
int i915_ttm_buddy_man_reserve(struct ttm_resource_manager *man,
u64 start, u64 size)
{
struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
struct i915_buddy_mm *mm = &bman->mm;
int ret;
mutex_lock(&bman->lock);
ret = i915_buddy_alloc_range(mm, &bman->reserved, start, size);
mutex_unlock(&bman->lock);
return ret;
}