diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 82 |
1 files changed, 44 insertions, 38 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index b9e914e1face..5769fe6e4950 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -30,16 +30,11 @@ * - Pages falling into physical memory gaps - not IORESOURCE_SYSRAM. Trying * to read/write these pages might end badly. Don't touch! * - The zero page(s) - * - Pages not added to the page allocator when onlining a section because - * they were excluded via the online_page_callback() or because they are - * PG_hwpoison. * - Pages allocated in the context of kexec/kdump (loaded kernel image, * control pages, vmcoreinfo) * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are * not marked PG_reserved (as they might be in use by somebody else who does * not respect the caching strategy). - * - Pages part of an offline section (struct pages of offline sections should - * not be trusted as they will be initialized when first onlined). * - MCA pages on ia64 * - Pages holding CPU notes for POWER Firmware Assisted Dump * - Device memory (e.g. PMEM, DAX, HMM) @@ -616,11 +611,6 @@ PAGEFLAG_FALSE(Uncached, uncached) PAGEFLAG(HWPoison, hwpoison, PF_ANY) TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) -#define MAGIC_HWPOISON 0x48575053U /* HWPS */ -extern void SetPageHWPoisonTakenOff(struct page *page); -extern void ClearPageHWPoisonTakenOff(struct page *page); -extern bool take_page_off_buddy(struct page *page); -extern bool put_page_back_buddy(struct page *page); #else PAGEFLAG_FALSE(HWPoison, hwpoison) #define __PG_HWPOISON 0 @@ -655,27 +645,28 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) #endif /* - * On an anonymous page mapped into a user virtual memory area, - * page->mapping points to its anon_vma, not to a struct address_space; + * On an anonymous folio mapped into a user virtual memory area, + * folio->mapping points to its anon_vma, not to a struct address_space; * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. * * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON - * bit; and then page->mapping points, not to an anon_vma, but to a private + * bit; and then folio->mapping points, not to an anon_vma, but to a private * structure which KSM associates with that merged page. See ksm.h. * * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable - * page and then page->mapping points to a struct movable_operations. + * page and then folio->mapping points to a struct movable_operations. * - * Please note that, confusingly, "page_mapping" refers to the inode - * address_space which maps the page from disk; whereas "page_mapped" - * refers to user virtual address space into which the page is mapped. + * Please note that, confusingly, "folio_mapping" refers to the inode + * address_space which maps the folio from disk; whereas "folio_mapped" + * refers to user virtual address space into which the folio is mapped. * * For slab pages, since slab reuses the bits in struct page to store its - * internal states, the page->mapping does not exist as such, nor do these - * flags below. So in order to avoid testing non-existent bits, please - * make sure that PageSlab(page) actually evaluates to false before calling - * the following functions (e.g., PageAnon). See mm/slab.h. + * internal states, the folio->mapping does not exist as such, nor do + * these flags below. So in order to avoid testing non-existent bits, + * please make sure that folio_test_slab(folio) actually evaluates to + * false before calling the following functions (e.g., folio_test_anon). + * See mm/slab.h. */ #define PAGE_MAPPING_ANON 0x1 #define PAGE_MAPPING_MOVABLE 0x2 @@ -945,22 +936,28 @@ PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) */ enum pagetype { - PG_buddy = 0x00000080, - PG_offline = 0x00000100, - PG_table = 0x00000200, - PG_guard = 0x00000400, - PG_hugetlb = 0x00000800, - PG_slab = 0x00001000, - - PAGE_TYPE_BASE = 0xf0000000, - /* Reserve 0x0000007f to catch underflows of _mapcount */ - PAGE_MAPCOUNT_RESERVE = -128, + PG_buddy = 0x40000000, + PG_offline = 0x20000000, + PG_table = 0x10000000, + PG_guard = 0x08000000, + PG_hugetlb = 0x04000000, + PG_slab = 0x02000000, + PG_zsmalloc = 0x01000000, + + PAGE_TYPE_BASE = 0x80000000, + + /* + * Reserve 0xffff0000 - 0xfffffffe to catch _mapcount underflows and + * allow owners that set a type to reuse the lower 16 bit for their own + * purposes. + */ + PAGE_MAPCOUNT_RESERVE = ~0x0000ffff, }; #define PageType(page, flag) \ - ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) + ((READ_ONCE(page->page_type) & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) #define folio_test_type(folio, flag) \ - ((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) + ((READ_ONCE(folio->page.page_type) & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) static inline int page_type_has_type(unsigned int page_type) { @@ -969,7 +966,7 @@ static inline int page_type_has_type(unsigned int page_type) static inline int page_has_type(const struct page *page) { - return page_type_has_type(page->page_type); + return page_type_has_type(READ_ONCE(page->page_type)); } #define FOLIO_TYPE_OPS(lname, fname) \ @@ -1018,15 +1015,22 @@ PAGE_TYPE_OPS(Buddy, buddy, buddy) * The content of these pages is effectively stale. Such pages should not * be touched (read/write/dump/save) except by their owner. * + * When a memory block gets onlined, all pages are initialized with a + * refcount of 1 and PageOffline(). generic_online_page() will + * take care of clearing PageOffline(). + * * If a driver wants to allow to offline unmovable PageOffline() pages without * putting them back to the buddy, it can do so via the memory notifier by * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() - * pages (now with a reference count of zero) are treated like free pages, - * allowing the containing memory block to get offlined. A driver that + * pages (now with a reference count of zero) are treated like free (unmanaged) + * pages, allowing the containing memory block to get offlined. A driver that * relies on this feature is aware that re-onlining the memory block will - * require to re-set the pages PageOffline() and not giving them to the - * buddy via online_page_callback_t. + * require not giving them to the buddy via generic_online_page(). + * + * Memory offlining code will not adjust the managed page count for any + * PageOffline() pages, treating them like they were never exposed to the + * buddy using generic_online_page(). * * There are drivers that mark a page PageOffline() and expect there won't be * any further access to page content. PFN walkers that read content of random @@ -1070,6 +1074,8 @@ FOLIO_TYPE_OPS(hugetlb, hugetlb) FOLIO_TEST_FLAG_FALSE(hugetlb) #endif +PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc) + /** * PageHuge - Determine if the page belongs to hugetlbfs * @page: The page to test. |