From cd3c93167da0e760b5819246eae7a4ea30fd014b Mon Sep 17 00:00:00 2001 From: Toke Høiland-Jørgensen Date: Wed, 9 Apr 2025 12:41:36 +0200 Subject: page_pool: Move pp_magic check into helper functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Reviewed-by: Mina Almasry Tested-by: Yonglong Liu Acked-by: Jesper Dangaard Brouer Reviewed-by: Ilias Apalodimas Signed-off-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20250409-page-pool-track-dma-v9-1-6a9ef2e0cba8@redhat.com Signed-off-by: Jakub Kicinski --- include/linux/mm.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/mm.h') diff --git a/include/linux/mm.h b/include/linux/mm.h index b7f13f087954..56c47f4a38ca 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4248,4 +4248,24 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); #define VM_SEALED_SYSMAP VM_NONE #endif +/* 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 + +#ifdef CONFIG_PAGE_POOL +static inline bool page_pool_page_is_pp(struct page *page) +{ + return (page->pp_magic & PP_MAGIC_MASK) == PP_SIGNATURE; +} +#else +static inline bool page_pool_page_is_pp(struct page *page) +{ + return false; +} +#endif + #endif /* _LINUX_MM_H */ -- cgit v1.2.3