diff mbox series

[net-next,1/3] page_pool: Move pp_magic check into helper functions

Message ID 20250314-page-pool-track-dma-v1-1-c212e57a74c2@redhat.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series Fix late DMA unmap crash for page pool | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/build_tools success Errors and warnings before: 26 (+0) this patch: 26 (+0)
netdev/cc_maintainers warning 3 maintainers not CCed: john.fastabend@gmail.com ast@kernel.org daniel@iogearbox.net
netdev/build_clang success Errors and warnings before: 6 this patch: 6
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 250 this patch: 250
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 129 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 55 this patch: 55
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2025-03-14--12-00 (tests: 896)

Commit Message

Toke Høiland-Jørgensen March 14, 2025, 10:10 a.m. UTC
Since we are about to stash some more information into the pp_magic
field, let's move the magic signature checks into a pair of helper
functions so it can be changed in one place.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c |  4 ++--
 include/net/page_pool/types.h                    | 18 ++++++++++++++++++
 mm/page_alloc.c                                  |  9 +++------
 net/core/netmem_priv.h                           |  5 +++++
 net/core/skbuff.c                                | 16 ++--------------
 net/core/xdp.c                                   |  4 ++--
 6 files changed, 32 insertions(+), 24 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 6f3094a479e1ec61854bb48a6a0c812167487173..70c6f0b2abb921778c98fbd428594ebd7986a302 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -706,8 +706,8 @@  static void mlx5e_free_xdpsq_desc(struct mlx5e_xdpsq *sq,
 				xdpi = mlx5e_xdpi_fifo_pop(xdpi_fifo);
 				page = xdpi.page.page;
 
-				/* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE)
-				 * as we know this is a page_pool page.
+				/* No need to check page_pool_page_is_pp() as we
+				 * know this is a page_pool page.
 				 */
 				page_pool_recycle_direct(page->pp, page);
 			} while (++n < num);
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 36eb57d73abc6cfc601e700ca08be20fb8281055..df0d3c1608929605224feb26173135ff37951ef8 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -54,6 +54,14 @@  struct pp_alloc_cache {
 	netmem_ref cache[PP_ALLOC_CACHE_SIZE];
 };
 
+/* Mask used for checking in page_pool_page_is_pp() below. page->pp_magic is
+ * OR'ed with PP_SIGNATURE after the allocation in order to preserve bit 0 for
+ * the head page of compound page and bit 1 for pfmemalloc page.
+ * page_is_pfmemalloc() is checked in __page_pool_put_page() to avoid recycling
+ * the pfmemalloc page.
+ */
+#define PP_MAGIC_MASK ~0x3UL
+
 /**
  * struct page_pool_params - page pool parameters
  * @fast:	params accessed frequently on hotpath
@@ -264,6 +272,11 @@  void page_pool_destroy(struct page_pool *pool);
 void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *),
 			   const struct xdp_mem_info *mem);
 void page_pool_put_netmem_bulk(netmem_ref *data, u32 count);
+
+static inline bool page_pool_page_is_pp(struct page *page)
+{
+	return (page->pp_magic & PP_MAGIC_MASK) == PP_SIGNATURE;
+}
 #else
 static inline void page_pool_destroy(struct page_pool *pool)
 {
@@ -278,6 +291,11 @@  static inline void page_pool_use_xdp_mem(struct page_pool *pool,
 static inline void page_pool_put_netmem_bulk(netmem_ref *data, u32 count)
 {
 }
+
+static inline bool page_pool_page_is_pp(struct page *page)
+{
+	return false;
+}
 #endif
 
 void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 579789600a3c7bfb7b0d847d51af702a9d4b139a..0268b68935ceb27d9781e59a474a234a6a61ea74 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -55,6 +55,7 @@ 
 #include <linux/delayacct.h>
 #include <linux/cacheinfo.h>
 #include <linux/pgalloc_tag.h>
+#include <net/page_pool/types.h>
 #include <asm/div64.h>
 #include "internal.h"
 #include "shuffle.h"
@@ -872,9 +873,7 @@  static inline bool page_expected_state(struct page *page,
 #ifdef CONFIG_MEMCG
 			page->memcg_data |
 #endif
-#ifdef CONFIG_PAGE_POOL
-			((page->pp_magic & ~0x3UL) == PP_SIGNATURE) |
-#endif
+			page_pool_page_is_pp(page) |
 			(page->flags & check_flags)))
 		return false;
 
@@ -901,10 +900,8 @@  static const char *page_bad_reason(struct page *page, unsigned long flags)
 	if (unlikely(page->memcg_data))
 		bad_reason = "page still charged to cgroup";
 #endif
-#ifdef CONFIG_PAGE_POOL
-	if (unlikely((page->pp_magic & ~0x3UL) == PP_SIGNATURE))
+	if (unlikely(page_pool_page_is_pp(page)))
 		bad_reason = "page_pool leak";
-#endif
 	return bad_reason;
 }
 
diff --git a/net/core/netmem_priv.h b/net/core/netmem_priv.h
index 7eadb8393e002fd1cc2cef8a313d2ea7df76f301..f33162fd281c23e109273ba09950c5d0a2829bc9 100644
--- a/net/core/netmem_priv.h
+++ b/net/core/netmem_priv.h
@@ -18,6 +18,11 @@  static inline void netmem_clear_pp_magic(netmem_ref netmem)
 	__netmem_clear_lsb(netmem)->pp_magic = 0;
 }
 
+static inline bool netmem_is_pp(netmem_ref netmem)
+{
+	return (netmem_get_pp_magic(netmem) & PP_MAGIC_MASK) == PP_SIGNATURE;
+}
+
 static inline void netmem_set_pp(netmem_ref netmem, struct page_pool *pool)
 {
 	__netmem_clear_lsb(netmem)->pp = pool;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index ab8acb737b93299f503e5c298b87e18edd59d555..a64d777488e403d5fdef83ae42ae9e4924c1a0dc 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -893,11 +893,6 @@  static void skb_clone_fraglist(struct sk_buff *skb)
 		skb_get(list);
 }
 
-static bool is_pp_netmem(netmem_ref netmem)
-{
-	return (netmem_get_pp_magic(netmem) & ~0x3UL) == PP_SIGNATURE;
-}
-
 int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
 		    unsigned int headroom)
 {
@@ -995,14 +990,7 @@  bool napi_pp_put_page(netmem_ref netmem)
 {
 	netmem = netmem_compound_head(netmem);
 
-	/* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation
-	 * in order to preserve any existing bits, such as bit 0 for the
-	 * head page of compound page and bit 1 for pfmemalloc page, so
-	 * mask those bits for freeing side when doing below checking,
-	 * and page_is_pfmemalloc() is checked in __page_pool_put_page()
-	 * to avoid recycling the pfmemalloc page.
-	 */
-	if (unlikely(!is_pp_netmem(netmem)))
+	if (unlikely(!netmem_is_pp(netmem)))
 		return false;
 
 	page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false);
@@ -1042,7 +1030,7 @@  static int skb_pp_frag_ref(struct sk_buff *skb)
 
 	for (i = 0; i < shinfo->nr_frags; i++) {
 		head_netmem = netmem_compound_head(shinfo->frags[i].netmem);
-		if (likely(is_pp_netmem(head_netmem)))
+		if (likely(netmem_is_pp(head_netmem)))
 			page_pool_ref_netmem(head_netmem);
 		else
 			page_ref_inc(netmem_to_page(head_netmem));
diff --git a/net/core/xdp.c b/net/core/xdp.c
index f86eedad586a77eb63a96a85aa6d068d3e94f077..0ba73943c6eed873b3d1c681b3b9a802b590f2d9 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -437,8 +437,8 @@  void __xdp_return(netmem_ref netmem, enum xdp_mem_type mem_type,
 		netmem = netmem_compound_head(netmem);
 		if (napi_direct && xdp_return_frame_no_direct())
 			napi_direct = false;
-		/* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE)
-		 * as mem->type knows this a page_pool page
+		/* No need to check netmem_is_pp() as mem->type knows this a
+		 * page_pool page
 		 */
 		page_pool_put_full_netmem(netmem_get_pp(netmem), netmem,
 					  napi_direct);