From 463586e9ff398f951a9a63d98a3b93f44434d20c Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Tue, 13 Aug 2024 21:54:50 -0600 Subject: [PATCH] mm/cma: add cma_{alloc,free}_folio() With alloc_contig_range() and free_contig_range() supporting large folios, CMA can allocate and free large folios too, by cma_alloc_folio() and cma_free_folio(). [yuzhao@google.com: fix WARN in cma_alloc_folio()] Link: https://lkml.kernel.org/r/Zsd0PgAQmbpR8jS6@google.com Link: https://lkml.kernel.org/r/20240814035451.773331-3-yuzhao@google.com Signed-off-by: Yu Zhao Acked-by: Zi Yan Cc: Frank van der Linden Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Signed-off-by: Andrew Morton --- include/linux/cma.h | 16 +++++++++++++ mm/cma.c | 55 ++++++++++++++++++++++++++++++++------------- 2 files changed, 56 insertions(+), 15 deletions(-) diff --git a/include/linux/cma.h b/include/linux/cma.h index 9db877506ea8..d15b64f51336 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -52,4 +52,20 @@ extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data); extern void cma_reserve_pages_on_error(struct cma *cma); + +#ifdef CONFIG_CMA +struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp); +bool cma_free_folio(struct cma *cma, const struct folio *folio); +#else +static inline struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp) +{ + return NULL; +} + +static inline bool cma_free_folio(struct cma *cma, const struct folio *folio) +{ + return false; +} +#endif + #endif diff --git a/mm/cma.c b/mm/cma.c index 95d6950e177b..2d9fae939283 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -403,18 +403,8 @@ static void cma_debug_show_areas(struct cma *cma) spin_unlock_irq(&cma->lock); } -/** - * cma_alloc() - allocate pages from contiguous area - * @cma: Contiguous memory region for which the allocation is performed. - * @count: Requested number of pages. - * @align: Requested alignment of pages (in PAGE_SIZE order). - * @no_warn: Avoid printing message about failed allocation - * - * This function allocates part of contiguous memory on specific - * contiguous memory area. - */ -struct page *cma_alloc(struct cma *cma, unsigned long count, - unsigned int align, bool no_warn) +static struct page *__cma_alloc(struct cma *cma, unsigned long count, + unsigned int align, gfp_t gfp) { unsigned long mask, offset; unsigned long pfn = -1; @@ -463,8 +453,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit); mutex_lock(&cma_mutex); - ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, - GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0)); + ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp); mutex_unlock(&cma_mutex); if (ret == 0) { page = pfn_to_page(pfn); @@ -494,7 +483,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, page_kasan_tag_reset(nth_page(page, i)); } - if (ret && !no_warn) { + if (ret && !(gfp & __GFP_NOWARN)) { pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n", __func__, cma->name, count, ret); cma_debug_show_areas(cma); @@ -513,6 +502,34 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, return page; } +/** + * cma_alloc() - allocate pages from contiguous area + * @cma: Contiguous memory region for which the allocation is performed. + * @count: Requested number of pages. + * @align: Requested alignment of pages (in PAGE_SIZE order). + * @no_warn: Avoid printing message about failed allocation + * + * This function allocates part of contiguous memory on specific + * contiguous memory area. + */ +struct page *cma_alloc(struct cma *cma, unsigned long count, + unsigned int align, bool no_warn) +{ + return __cma_alloc(cma, count, align, GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0)); +} + +struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp) +{ + struct page *page; + + if (WARN_ON(!order || !(gfp & __GFP_COMP))) + return NULL; + + page = __cma_alloc(cma, 1 << order, order, gfp); + + return page ? page_folio(page) : NULL; +} + bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count) { @@ -564,6 +581,14 @@ bool cma_release(struct cma *cma, const struct page *pages, return true; } +bool cma_free_folio(struct cma *cma, const struct folio *folio) +{ + if (WARN_ON(!folio_test_large(folio))) + return false; + + return cma_release(cma, &folio->page, folio_nr_pages(folio)); +} + int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data) { int i;