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authorByungchul Park <byungchul@sk.com>2025-07-21 11:18:26 +0900
committerJakub Kicinski <kuba@kernel.org>2025-07-23 17:46:54 -0700
commit89ade7c7306508f46b811cd43960eaed88e0e1dd (patch)
tree7fbbc2d65d83ab468de6c569cb9833c5dc44dc39 /include/net
parent38a436d4e26487e16ac6c1de17c030b1bef84d83 (diff)
netmem, mlx4: access ->pp_ref_count through netmem_desc instead of page
To eliminate the use of struct page in page pool, the page pool users should use netmem descriptor and APIs instead. Make mlx4 access ->pp_ref_count through netmem_desc instead of page. While at it, add a helper, pp_page_to_nmdesc() and __pp_page_to_nmdesc(), that can be used to get netmem_desc from page only if it's a pp page. For now that netmem_desc overlays on page, it can be achieved by just casting, and use macro and _Generic to cover const casting as well. Plus, change page_pool_page_is_pp() to check for 'const struct page *' instead of 'struct page *' since it doesn't modify data and additionally covers const type. Signed-off-by: Byungchul Park <byungchul@sk.com> Link: https://patch.msgid.link/20250721021835.63939-4-byungchul@sk.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/netmem.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/net/netmem.h b/include/net/netmem.h
index 097bc74d9555..f7dacc9e75fd 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -285,6 +285,23 @@ static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem)
return (struct net_iov *)((__force unsigned long)netmem & ~NET_IOV);
}
+/* XXX: How to extract netmem_desc from page must be changed, once
+ * netmem_desc no longer overlays on page and will be allocated through
+ * slab.
+ */
+#define __pp_page_to_nmdesc(p) (_Generic((p), \
+ const struct page * : (const struct netmem_desc *)(p), \
+ struct page * : (struct netmem_desc *)(p)))
+
+/* CAUTION: Check if the page is a pp page before calling this helper or
+ * know it's a pp page.
+ */
+#define pp_page_to_nmdesc(p) \
+({ \
+ DEBUG_NET_WARN_ON_ONCE(!page_pool_page_is_pp(p)); \
+ __pp_page_to_nmdesc(p); \
+})
+
/**
* __netmem_get_pp - unsafely get pointer to the &page_pool backing @netmem
* @netmem: netmem reference to get the pointer from