Prepare to reduce dependencies on linux/mm.h. folio_size()/page_size() are used by the following popular headers: - linux/highmem.h - linux/iov_iter.h - linux/pagemap.h Moving them to a separate lean header will allow us to avoid the dependency on linux/mm.h. Additionally, it allows us to move folio_next() to a separate header, because it needs folio_nr_pages() which is also moved to folio_size.h. Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx> --- include/linux/mm.h | 140 +------------------------------ include/linux/mm/folio_size.h | 150 ++++++++++++++++++++++++++++++++++ 2 files changed, 151 insertions(+), 139 deletions(-) create mode 100644 include/linux/mm/folio_size.h diff --git a/include/linux/mm.h b/include/linux/mm.h index 0dea734194aa..d5019aed8330 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2,6 +2,7 @@ #ifndef _LINUX_MM_H #define _LINUX_MM_H +#include <linux/mm/folio_size.h> #include <linux/mm/page_address.h> #include <linux/mm/page_section.h> #include <linux/errno.h> @@ -1069,38 +1070,6 @@ int vma_is_stack_for_current(struct vm_area_struct *vma); struct mmu_gather; struct inode; -/* - * compound_order() can be called without holding a reference, which means - * that niceties like page_folio() don't work. These callers should be - * prepared to handle wild return values. For example, PG_head may be - * set before the order is initialised, or this may be a tail page. - * See compaction.c for some good examples. - */ -static inline unsigned int compound_order(struct page *page) -{ - struct folio *folio = (struct folio *)page; - - if (!test_bit(PG_head, &folio->flags)) - return 0; - return folio->_flags_1 & 0xff; -} - -/** - * folio_order - The allocation order of a folio. - * @folio: The folio. - * - * A folio is composed of 2^order pages. See get_order() for the definition - * of order. - * - * Return: The order of the folio. - */ -static inline unsigned int folio_order(struct folio *folio) -{ - if (!folio_test_large(folio)) - return 0; - return folio->_flags_1 & 0xff; -} - #include <linux/huge_mm.h> /* @@ -1313,39 +1282,6 @@ void folio_copy(struct folio *dst, struct folio *src); unsigned long nr_free_buffer_pages(void); -/* Returns the number of bytes in this potentially compound page. */ -static inline unsigned long page_size(struct page *page) -{ - return PAGE_SIZE << compound_order(page); -} - -/* Returns the number of bits needed for the number of bytes in a page */ -static inline unsigned int page_shift(struct page *page) -{ - return PAGE_SHIFT + compound_order(page); -} - -/** - * thp_order - Order of a transparent huge page. - * @page: Head page of a transparent huge page. - */ -static inline unsigned int thp_order(struct page *page) -{ - VM_BUG_ON_PGFLAGS(PageTail(page), page); - return compound_order(page); -} - -/** - * thp_size - Size of a transparent huge page. - * @page: Head page of a transparent huge page. - * - * Return: Number of bytes in this page. - */ -static inline unsigned long thp_size(struct page *page) -{ - return PAGE_SIZE << thp_order(page); -} - #ifdef CONFIG_MMU /* * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when @@ -1981,23 +1917,6 @@ static inline void set_page_links(struct page *page, enum zone_type zone, #endif } -/** - * folio_nr_pages - The number of pages in the folio. - * @folio: The folio. - * - * Return: A positive power of two. - */ -static inline long folio_nr_pages(const struct folio *folio) -{ - if (!folio_test_large(folio)) - return 1; -#ifdef CONFIG_64BIT - return folio->_folio_nr_pages; -#else - return 1L << (folio->_flags_1 & 0xff); -#endif -} - /* Only hugetlbfs can allocate folios larger than MAX_ORDER */ #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE #define MAX_FOLIO_NR_PAGES (1UL << PUD_ORDER) @@ -2005,33 +1924,6 @@ static inline long folio_nr_pages(const struct folio *folio) #define MAX_FOLIO_NR_PAGES MAX_ORDER_NR_PAGES #endif -/* - * compound_nr() returns the number of pages in this potentially compound - * page. compound_nr() can be called on a tail page, and is defined to - * return 1 in that case. - */ -static inline unsigned long compound_nr(struct page *page) -{ - struct folio *folio = (struct folio *)page; - - if (!test_bit(PG_head, &folio->flags)) - return 1; -#ifdef CONFIG_64BIT - return folio->_folio_nr_pages; -#else - return 1L << (folio->_flags_1 & 0xff); -#endif -} - -/** - * thp_nr_pages - The number of regular pages in this huge page. - * @page: The head page of a huge page. - */ -static inline int thp_nr_pages(struct page *page) -{ - return folio_nr_pages((struct folio *)page); -} - /** * folio_next - Move to the next physical folio. * @folio: The folio we're currently operating on. @@ -2051,36 +1943,6 @@ static inline struct folio *folio_next(struct folio *folio) return (struct folio *)folio_page(folio, folio_nr_pages(folio)); } -/** - * folio_shift - The size of the memory described by this folio. - * @folio: The folio. - * - * A folio represents a number of bytes which is a power-of-two in size. - * This function tells you which power-of-two the folio is. See also - * folio_size() and folio_order(). - * - * Context: The caller should have a reference on the folio to prevent - * it from being split. It is not necessary for the folio to be locked. - * Return: The base-2 logarithm of the size of this folio. - */ -static inline unsigned int folio_shift(struct folio *folio) -{ - return PAGE_SHIFT + folio_order(folio); -} - -/** - * folio_size - The number of bytes in a folio. - * @folio: The folio. - * - * Context: The caller should have a reference on the folio to prevent - * it from being split. It is not necessary for the folio to be locked. - * Return: The number of bytes in this folio. - */ -static inline size_t folio_size(struct folio *folio) -{ - return PAGE_SIZE << folio_order(folio); -} - /** * folio_likely_mapped_shared - Estimate if the folio is mapped into the page * tables of more than one MM diff --git a/include/linux/mm/folio_size.h b/include/linux/mm/folio_size.h new file mode 100644 index 000000000000..e7cd567cf069 --- /dev/null +++ b/include/linux/mm/folio_size.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_MM_FOLIO_SIZE_H +#define _LINUX_MM_FOLIO_SIZE_H + +#include <linux/bitops.h> // for test_bit() +#include <linux/mmdebug.h> // for VM_BUG_ON_PGFLAGS() +#include <linux/mm_types.h> // for struct page +#include <linux/page-flags.h> // for folio_test_large() +#include <asm/page.h> // for PAGE_SIZE, PAGE_SHIFT + +/* + * compound_order() can be called without holding a reference, which means + * that niceties like page_folio() don't work. These callers should be + * prepared to handle wild return values. For example, PG_head may be + * set before the order is initialised, or this may be a tail page. + * See compaction.c for some good examples. + */ +static inline unsigned int compound_order(struct page *page) +{ + struct folio *folio = (struct folio *)page; + + if (!test_bit(PG_head, &folio->flags)) + return 0; + return folio->_flags_1 & 0xff; +} + +/** + * folio_order - The allocation order of a folio. + * @folio: The folio. + * + * A folio is composed of 2^order pages. See get_order() for the definition + * of order. + * + * Return: The order of the folio. + */ +static inline unsigned int folio_order(struct folio *folio) +{ + if (!folio_test_large(folio)) + return 0; + return folio->_flags_1 & 0xff; +} + +/* Returns the number of bytes in this potentially compound page. */ +static inline unsigned long page_size(struct page *page) +{ + return PAGE_SIZE << compound_order(page); +} + +/* Returns the number of bits needed for the number of bytes in a page */ +static inline unsigned int page_shift(struct page *page) +{ + return PAGE_SHIFT + compound_order(page); +} + +/** + * thp_order - Order of a transparent huge page. + * @page: Head page of a transparent huge page. + */ +static inline unsigned int thp_order(struct page *page) +{ + VM_BUG_ON_PGFLAGS(PageTail(page), page); + return compound_order(page); +} + +/** + * thp_size - Size of a transparent huge page. + * @page: Head page of a transparent huge page. + * + * Return: Number of bytes in this page. + */ +static inline unsigned long thp_size(struct page *page) +{ + return PAGE_SIZE << thp_order(page); +} + +/** + * folio_nr_pages - The number of pages in the folio. + * @folio: The folio. + * + * Return: A positive power of two. + */ +static inline long folio_nr_pages(const struct folio *folio) +{ + if (!folio_test_large(folio)) + return 1; +#ifdef CONFIG_64BIT + return folio->_folio_nr_pages; +#else + return 1L << (folio->_flags_1 & 0xff); +#endif +} + +/* + * compound_nr() returns the number of pages in this potentially compound + * page. compound_nr() can be called on a tail page, and is defined to + * return 1 in that case. + */ +static inline unsigned long compound_nr(struct page *page) +{ + struct folio *folio = (struct folio *)page; + + if (!test_bit(PG_head, &folio->flags)) + return 1; +#ifdef CONFIG_64BIT + return folio->_folio_nr_pages; +#else + return 1L << (folio->_flags_1 & 0xff); +#endif +} + +/** + * thp_nr_pages - The number of regular pages in this huge page. + * @page: The head page of a huge page. + */ +static inline int thp_nr_pages(struct page *page) +{ + return folio_nr_pages((struct folio *)page); +} + +/** + * folio_shift - The size of the memory described by this folio. + * @folio: The folio. + * + * A folio represents a number of bytes which is a power-of-two in size. + * This function tells you which power-of-two the folio is. See also + * folio_size() and folio_order(). + * + * Context: The caller should have a reference on the folio to prevent + * it from being split. It is not necessary for the folio to be locked. + * Return: The base-2 logarithm of the size of this folio. + */ +static inline unsigned int folio_shift(struct folio *folio) +{ + return PAGE_SHIFT + folio_order(folio); +} + +/** + * folio_size - The number of bytes in a folio. + * @folio: The folio. + * + * Context: The caller should have a reference on the folio to prevent + * it from being split. It is not necessary for the folio to be locked. + * Return: The number of bytes in this folio. + */ +static inline size_t folio_size(struct folio *folio) +{ + return PAGE_SIZE << folio_order(folio); +} + +#endif /* _LINUX_MM_FOLIO_SIZE_H_H */ -- 2.39.2