This is a note to let you know that I've just added the patch titled
drm/ttm/pool: Fix ttm_pool_alloc error path
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-ttm-pool-fix-ttm_pool_alloc-error-path.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c89f99f0b97eabae552565177b09fdf6cc032da2
Author: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Date: Tue Apr 4 22:06:48 2023 +0200
drm/ttm/pool: Fix ttm_pool_alloc error path
[ Upstream commit 379989e7cbdc7aa7496a00ee286ec146c7599cf0 ]
When hitting an error, the error path forgot to unmap dma mappings and
could call set_pages_wb() on already uncached pages.
Fix this by introducing a common ttm_pool_free_range() function that
does the right thing.
v2:
- Simplify that common function (Christian König)
v3:
- Rename that common function to ttm_pool_free_range() (Christian König)
Fixes: d099fc8f540a ("drm/ttm: new TT backend allocation pool v3")
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: Christian Koenig <christian.koenig@xxxxxxx>
Cc: Huang Rui <ray.huang@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230404200650.11043-2-thomas.hellstrom@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index 9f6764bf3b15d..86affe987a1cb 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -366,6 +366,43 @@ static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
return 0;
}
+/**
+ * ttm_pool_free_range() - Free a range of TTM pages
+ * @pool: The pool used for allocating.
+ * @tt: The struct ttm_tt holding the page pointers.
+ * @caching: The page caching mode used by the range.
+ * @start_page: index for first page to free.
+ * @end_page: index for last page to free + 1.
+ *
+ * During allocation the ttm_tt page-vector may be populated with ranges of
+ * pages with different attributes if allocation hit an error without being
+ * able to completely fulfill the allocation. This function can be used
+ * to free these individual ranges.
+ */
+static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt,
+ enum ttm_caching caching,
+ pgoff_t start_page, pgoff_t end_page)
+{
+ struct page **pages = tt->pages;
+ unsigned int order;
+ pgoff_t i, nr;
+
+ for (i = start_page; i < end_page; i += nr, pages += nr) {
+ struct ttm_pool_type *pt = NULL;
+
+ order = ttm_pool_page_order(pool, *pages);
+ nr = (1UL << order);
+ if (tt->dma_address)
+ ttm_pool_unmap(pool, tt->dma_address[i], nr);
+
+ pt = ttm_pool_select_type(pool, caching, order);
+ if (pt)
+ ttm_pool_type_give(pt, *pages);
+ else
+ ttm_pool_free_page(pool, caching, order, *pages);
+ }
+}
+
/**
* ttm_pool_alloc - Fill a ttm_tt object
*
@@ -381,12 +418,14 @@ static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
struct ttm_operation_ctx *ctx)
{
- unsigned long num_pages = tt->num_pages;
+ pgoff_t num_pages = tt->num_pages;
dma_addr_t *dma_addr = tt->dma_address;
struct page **caching = tt->pages;
struct page **pages = tt->pages;
+ enum ttm_caching page_caching;
gfp_t gfp_flags = GFP_USER;
- unsigned int i, order;
+ pgoff_t caching_divide;
+ unsigned int order;
struct page *p;
int r;
@@ -409,6 +448,7 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
order = min_t(unsigned int, order, __fls(num_pages))) {
struct ttm_pool_type *pt;
+ page_caching = tt->caching;
pt = ttm_pool_select_type(pool, tt->caching, order);
p = pt ? ttm_pool_type_take(pt) : NULL;
if (p) {
@@ -417,6 +457,7 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
if (r)
goto error_free_page;
+ caching = pages;
do {
r = ttm_pool_page_allocated(pool, order, p,
&dma_addr,
@@ -425,14 +466,15 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
if (r)
goto error_free_page;
+ caching = pages;
if (num_pages < (1 << order))
break;
p = ttm_pool_type_take(pt);
} while (p);
- caching = pages;
}
+ page_caching = ttm_cached;
while (num_pages >= (1 << order) &&
(p = ttm_pool_alloc_page(pool, gfp_flags, order))) {
@@ -441,6 +483,7 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
tt->caching);
if (r)
goto error_free_page;
+ caching = pages;
}
r = ttm_pool_page_allocated(pool, order, p, &dma_addr,
&num_pages, &pages);
@@ -467,15 +510,13 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
return 0;
error_free_page:
- ttm_pool_free_page(pool, tt->caching, order, p);
+ ttm_pool_free_page(pool, page_caching, order, p);
error_free_all:
num_pages = tt->num_pages - num_pages;
- for (i = 0; i < num_pages; ) {
- order = ttm_pool_page_order(pool, tt->pages[i]);
- ttm_pool_free_page(pool, tt->caching, order, tt->pages[i]);
- i += 1 << order;
- }
+ caching_divide = caching - tt->pages;
+ ttm_pool_free_range(pool, tt, tt->caching, 0, caching_divide);
+ ttm_pool_free_range(pool, tt, ttm_cached, caching_divide, num_pages);
return r;
}
@@ -491,27 +532,7 @@ EXPORT_SYMBOL(ttm_pool_alloc);
*/
void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
{
- unsigned int i;
-
- for (i = 0; i < tt->num_pages; ) {
- struct page *p = tt->pages[i];
- unsigned int order, num_pages;
- struct ttm_pool_type *pt;
-
- order = ttm_pool_page_order(pool, p);
- num_pages = 1ULL << order;
- if (tt->dma_address)
- ttm_pool_unmap(pool, tt->dma_address[i], num_pages);
-
- pt = ttm_pool_select_type(pool, tt->caching, order);
- if (pt)
- ttm_pool_type_give(pt, tt->pages[i]);
- else
- ttm_pool_free_page(pool, tt->caching, order,
- tt->pages[i]);
-
- i += num_pages;
- }
+ ttm_pool_free_range(pool, tt, tt->caching, 0, tt->num_pages);
while (atomic_long_read(&allocated_pages) > page_pool_size)
ttm_pool_shrink();
