Commit 9871e2de authored by Mike Kravetz's avatar Mike Kravetz Committed by Linus Torvalds
Browse files

mm/cma: add cma_pages_valid to determine if pages are in CMA 

Add new interface cma_pages_valid() which indicates if the specified
pages are part of a CMA region.  This interface will be used in a
subsequent patch by hugetlb code.

In order to keep the same amount of DEBUG information, a pr_debug() call
was added to cma_pages_valid().  In the case where the page passed to
cma_release is not in cma region, the debug message will be printed from
cma_pages_valid as opposed to cma_release.

Link: https://lkml.kernel.org/r/20211007181918.136982-3-mike.kravetz@oracle.com


Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Nghia Le <nghialm78@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 79dfc695

include/linux/cma.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, 
					struct cma **res_cma);

extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,

			      bool no_warn);

extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);

extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long count);



extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);

mm/cma.c

+20 −4
Original line number Diff line number Diff line
@@ -524,6 +524,25 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, 
	return page;

}



bool cma_pages_valid(struct cma *cma, const struct page *pages,

		     unsigned long count)

{

	unsigned long pfn;



	if (!cma || !pages)

		return false;



	pfn = page_to_pfn(pages);



	if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count) {

		pr_debug("%s(page %p, count %lu)\n", __func__,

						(void *)pages, count);

		return false;

	}



	return true;

}



/**

 * cma_release() - release allocated pages

 * @cma:   Contiguous memory region for which the allocation is performed.
@@ -539,16 +558,13 @@ bool cma_release(struct cma *cma, const struct page *pages, 
{

	unsigned long pfn;



	if (!cma || !pages)

	if (!cma_pages_valid(cma, pages, count))

		return false;



	pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);



	pfn = page_to_pfn(pages);



	if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)

		return false;



	VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);



	free_contig_range(pfn, count);