[RFC PATCH 4/6] udmabuf: use vmap_range_folios

Huan Yang link at vivo.com
Thu Mar 27 09:28:31 UTC 2025


This patch change udmabuf from use pfn based into folio based vmap.

Signed-off-by: Huan Yang <link at vivo.com>
---
 drivers/dma-buf/udmabuf.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index fbe4b59b4c97..f50e11f0f034 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -152,29 +152,28 @@ static void *udmabuf_vmap_pfn(unsigned long *pfns, unsigned int count,
 static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map)
 {
 	struct udmabuf *ubuf = buf->priv;
-	unsigned long *pfns;
+	struct vmap_folios_struct folios;
+	struct vmap_folios_range *ranges;
 	void *vaddr;
 	pgoff_t pg;
 
 	dma_resv_assert_held(buf->resv);
 
-	/**
-	 * HVO may free tail pages, so just use pfn to map each folio
-	 * into vmalloc area.
-	 */
-	pfns = kvmalloc_array(ubuf->pagecount, sizeof(*pfns), GFP_KERNEL);
-	if (!pfns)
+	ranges = kvmalloc_array(ubuf->pagecount, sizeof(*ranges), GFP_KERNEL);
+	if (!ranges)
 		return -ENOMEM;
 
 	for (pg = 0; pg < ubuf->pagecount; pg++) {
-		unsigned long pfn = folio_pfn(ubuf->folios[pg]);
-
-		pfn += ubuf->offsets[pg] >> PAGE_SHIFT;
-		pfns[pg] = pfn;
+		ranges[pg].folio = ubuf->folios[pg];
+		ranges[pg].pgoff = ubuf->offsets[pg] >> PAGE_SHIFT;
+		ranges[pg].nr_pages = 1;
 	}
 
-	vaddr = udmabuf_vmap_pfn(pfns, ubuf->pagecount, PAGE_KERNEL);
-	kvfree(pfns);
+	folios._range_folios = ranges;
+	folios.range = true;
+
+	vaddr = vmap_range_folios(&folios, ubuf->pagecount, 0, PAGE_KERNEL);
+	kvfree(ranges);
 	if (!vaddr)
 		return -EINVAL;
 
-- 
2.48.1



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