drm/ttm: Add a flag to allow drivers to skip clear-on-free

Add TTM_TT_FLAG_CLEARED_ON_FREE, which DRM drivers can set before
releasing backing stores if they want to skip clear-on-free.

Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240816135154.19678-1-nirmoy.das@intel.com
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
This commit is contained in:
Nirmoy Das 2024-08-16 15:51:53 +02:00
parent 6841a26e2c
commit decbfaf06d
2 changed files with 16 additions and 8 deletions

View File

@ -222,15 +222,18 @@ static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
}
/* Give pages into a specific pool_type */
static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p,
bool cleared)
{
unsigned int i, num_pages = 1 << pt->order;
for (i = 0; i < num_pages; ++i) {
if (PageHighMem(p))
clear_highpage(p + i);
else
clear_page(page_address(p + i));
if (!cleared) {
for (i = 0; i < num_pages; ++i) {
if (PageHighMem(p))
clear_highpage(p + i);
else
clear_page(page_address(p + i));
}
}
spin_lock(&pt->lock);
@ -394,6 +397,7 @@ static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt,
pgoff_t start_page, pgoff_t end_page)
{
struct page **pages = &tt->pages[start_page];
bool cleared = tt->page_flags & TTM_TT_FLAG_CLEARED_ON_FREE;
unsigned int order;
pgoff_t i, nr;
@ -407,7 +411,7 @@ static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt,
pt = ttm_pool_select_type(pool, caching, order);
if (pt)
ttm_pool_type_give(pt, *pages);
ttm_pool_type_give(pt, *pages, cleared);
else
ttm_pool_free_page(pool, caching, order, *pages);
}

View File

@ -85,6 +85,9 @@ struct ttm_tt {
* fault handling abuses the DMA api a bit and dma_map_attrs can't be
* used to assure pgprot always matches.
*
* TTM_TT_FLAG_CLEARED_ON_FREE: Set this if a drm driver handles
* clearing backing store
*
* TTM_TT_FLAG_PRIV_POPULATED: TTM internal only. DO NOT USE. This is
* set by TTM after ttm_tt_populate() has successfully returned, and is
* then unset when TTM calls ttm_tt_unpopulate().
@ -94,8 +97,9 @@ struct ttm_tt {
#define TTM_TT_FLAG_EXTERNAL BIT(2)
#define TTM_TT_FLAG_EXTERNAL_MAPPABLE BIT(3)
#define TTM_TT_FLAG_DECRYPTED BIT(4)
#define TTM_TT_FLAG_CLEARED_ON_FREE BIT(5)
#define TTM_TT_FLAG_PRIV_POPULATED BIT(5)
#define TTM_TT_FLAG_PRIV_POPULATED BIT(6)
uint32_t page_flags;
/** @num_pages: Number of pages in the page array. */
uint32_t num_pages;