diff options
| author | Byungchul Park <byungchul@sk.com> | 2025-07-21 11:18:26 +0900 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-23 17:46:54 -0700 |
| commit | 89ade7c7306508f46b811cd43960eaed88e0e1dd (patch) | |
| tree | 7fbbc2d65d83ab468de6c569cb9833c5dc44dc39 /include | |
| parent | 38a436d4e26487e16ac6c1de17c030b1bef84d83 (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')
| -rw-r--r-- | include/linux/mm.h | 4 | ||||
| -rw-r--r-- | include/net/netmem.h | 17 |
2 files changed, 19 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index fa538feaa8d9..ae50c1641bed 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4178,12 +4178,12 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); #define PP_MAGIC_MASK ~(PP_DMA_INDEX_MASK | 0x3UL) #ifdef CONFIG_PAGE_POOL -static inline bool page_pool_page_is_pp(struct page *page) +static inline bool page_pool_page_is_pp(const struct page *page) { return (page->pp_magic & PP_MAGIC_MASK) == PP_SIGNATURE; } #else -static inline bool page_pool_page_is_pp(struct page *page) +static inline bool page_pool_page_is_pp(const struct page *page) { return false; } 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 |