On 09/06/2023 15.17, Yunsheng Lin wrote:
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index a7c526ee5024..cd4ac378cc63 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -832,6 +832,15 @@ static int mlx5e_alloc_rq(struct mlx5e_params *params,
/* Create a page_pool and register it with rxq */
struct page_pool_params pp_params = { 0 };
+ /* Return error here to aoivd writing to page->pp_frag_count in
^^^^^
Typo
+ * mlx5e_page_release_fragmented() for page->pp_frag_count is not
+ * usable for arch with PAGE_POOL_DMA_USE_PP_FRAG_COUNT being true.
+ */
+ if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) {
+ err = -EINVAL;
+ goto err_free_by_rq_type;
+ }
+
pp_params.order = 0;
pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV | PP_FLAG_PAGE_FRAG;
pp_params.pool_size = pool_size;
diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index 126f9e294389..5c7f7501f300 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -33,6 +33,7 @@
#include <linux/mm.h> /* Needed by ptr_ring */
#include <linux/ptr_ring.h>
#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
#define PP_FLAG_DMA_MAP BIT(0) /* Should page_pool do the DMA
* map/unmap
@@ -50,6 +51,9 @@
PP_FLAG_DMA_SYNC_DEV |\
PP_FLAG_PAGE_FRAG)
+#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \
+ (sizeof(dma_addr_t) > sizeof(unsigned long))
+
I have a problem with the name PAGE_POOL_DMA_USE_PP_FRAG_COUNT
because it is confusing to read in an if-statement.
Proposals rename to: DMA_OVERLAP_PP_FRAG_COUNT
Or: MM_DMA_OVERLAP_PP_FRAG_COUNT
Or: DMA_ADDR_OVERLAP_PP_FRAG_COUNT
Notice how I also removed the prefix PAGE_POOL_ because this is a
MM-layer constraint and not a property of page_pool.
--Jesper
