Commit 463586e9 authored by Yu Zhao's avatar Yu Zhao Committed by Andrew Morton
Browse files

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: default avatarYu Zhao <yuzhao@google.com>
Acked-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e98337d1

include/linux/cma.h

+16 −0
Original line number Diff line number Diff line
@@ -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

mm/cma.c

+40 −15
Original line number Diff line number Diff line
@@ -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;