+ mm-cma-add-__cma_release.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: cma: add __cma_release()
has been added to the -mm mm-new branch.  Its filename is
     mm-cma-add-__cma_release.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-cma-add-__cma_release.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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fixup patches in mm-new.

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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: cma: add __cma_release()
Date: Thu, 23 Oct 2025 19:59:37 +0800

Kill cma_pages_valid() which only used in cma_release(), also cleanup code
duplication between cma pages valid checking and cma memrange finding, add
__cma_release() helper to prepare for the upcoming frozen page release.

Link: https://lkml.kernel.org/r/20251023115940.3573158-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/cma.h |    1 
 mm/cma.c            |   62 ++++++++++++++----------------------------
 2 files changed, 21 insertions(+), 42 deletions(-)

--- a/include/linux/cma.h~mm-cma-add-__cma_release
+++ a/include/linux/cma.h
@@ -49,7 +49,6 @@ extern int cma_init_reserved_mem(phys_ad
 					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);
--- a/mm/cma.c~mm-cma-add-__cma_release
+++ a/mm/cma.c
@@ -942,34 +942,43 @@ struct folio *cma_alloc_folio(struct cma
 	return page ? page_folio(page) : NULL;
 }
 
-bool cma_pages_valid(struct cma *cma, const struct page *pages,
-		     unsigned long count)
+static bool __cma_release(struct cma *cma, const struct page *pages,
+			  unsigned long count)
 {
 	unsigned long pfn, end;
 	int r;
 	struct cma_memrange *cmr;
-	bool ret;
+
+	pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
 
 	if (!cma || !pages || count > cma->count)
 		return false;
 
 	pfn = page_to_pfn(pages);
-	ret = false;
 
 	for (r = 0; r < cma->nranges; r++) {
 		cmr = &cma->ranges[r];
 		end = cmr->base_pfn + cmr->count;
 		if (pfn >= cmr->base_pfn && pfn < end) {
-			ret = pfn + count <= end;
-			break;
+			if (pfn + count <= end)
+				break;
+
+			VM_WARN_ON_ONCE(1);
 		}
 	}
 
-	if (!ret)
-		pr_debug("%s(page %p, count %lu)\n",
-				__func__, (void *)pages, count);
+	if (r == cma->nranges) {
+		pr_debug("%s(page %p, count %lu, no cma range matches the page range)\n",
+			 __func__, (void *)pages, count);
+		return false;
+	}
 
-	return ret;
+	free_contig_range(pfn, count);
+	cma_clear_bitmap(cma, cmr, pfn, count);
+	cma_sysfs_account_release_pages(cma, count);
+	trace_cma_release(cma->name, pfn, pages, count);
+
+	return true;
 }
 
 /**
@@ -985,36 +994,7 @@ bool cma_pages_valid(struct cma *cma, co
 bool cma_release(struct cma *cma, const struct page *pages,
 		 unsigned long count)
 {
-	struct cma_memrange *cmr;
-	unsigned long pfn, end_pfn;
-	int r;
-
-	pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
-
-	if (!cma_pages_valid(cma, pages, count))
-		return false;
-
-	pfn = page_to_pfn(pages);
-	end_pfn = pfn + count;
-
-	for (r = 0; r < cma->nranges; r++) {
-		cmr = &cma->ranges[r];
-		if (pfn >= cmr->base_pfn &&
-		    pfn < (cmr->base_pfn + cmr->count)) {
-			VM_BUG_ON(end_pfn > cmr->base_pfn + cmr->count);
-			break;
-		}
-	}
-
-	if (r == cma->nranges)
-		return false;
-
-	free_contig_range(pfn, count);
-	cma_clear_bitmap(cma, cmr, pfn, count);
-	cma_sysfs_account_release_pages(cma, count);
-	trace_cma_release(cma->name, pfn, pages, count);
-
-	return true;
+	return __cma_release(cma, pages, count);
 }
 
 bool cma_free_folio(struct cma *cma, const struct folio *folio)
@@ -1022,7 +1002,7 @@ bool cma_free_folio(struct cma *cma, con
 	if (WARN_ON(!folio_test_large(folio)))
 		return false;
 
-	return cma_release(cma, &folio->page, folio_nr_pages(folio));
+	return __cma_release(cma, &folio->page, folio_nr_pages(folio));
 }
 
 int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-mprotect-always-skip-dma-pinned-folio-in-prot_numa_skip.patch
mm-mprotect-avoid-unnecessary-struct-page-accessing-if-pte_protnone.patch
mm-huge_memory-use-folio_skip_prot_numa-for-pmd-folio.patch
mm-debug_vm_pgtable-add-debug_vm_pgtable_free_huge_page.patch
mm-page_alloc-add-__split_page.patch
mm-cma-add-__cma_release.patch
mm-page_alloc-add-alloc_contig_frozen_rangepages.patch
mm-cma-add-cma_alloc_frozen_compound.patch
mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio.patch