[RFC PATCH 5/6] udmabuf: vmap test suit for pages and pfns compare

[Huan Yang]

This patch both compare pages and pfns based vmap, to show folios
range vmap and pfn range vmap can work.

Signed-off-by: Huan Yang <link@xxxxxxxx>
---
 drivers/dma-buf/udmabuf.c | 64 ++++++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 18 deletions(-)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index f50e11f0f034..78549a9f24ca 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -556,6 +556,48 @@ static long udmabuf_ioctl_create_list(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static void *udmabuf_vmap_by_pfns(struct udmabuf *udmabuf)
+{
+	unsigned long *pfns;
+	void *vaddr = NULL;
+	unsigned int i;
+
+	pfns = kvmalloc_array(udmabuf->pagecount, sizeof(*pfns), GFP_KERNEL);
+	if (WARN_ON(!pfns))
+		return NULL;
+
+	for (i = 0; i < udmabuf->pagecount; ++i)
+		pfns[i] = folio_pfn(udmabuf->folios[i]) +
+			  (udmabuf->offsets[i] >> PAGE_SHIFT);
+
+	vaddr = udmabuf_vmap_pfn(pfns, udmabuf->pagecount, PAGE_KERNEL);
+	WARN_ON(!vaddr);
+
+	kvfree(pfns);
+	return vaddr;
+}
+
+static void *udmabuf_vmap_by_pages(struct udmabuf *udmabuf)
+{
+	struct page **pages;
+	void *vaddr = NULL;
+	unsigned int i;
+
+	pages = kvmalloc_array(udmabuf->pagecount, sizeof(*pages), GFP_KERNEL);
+	if (WARN_ON(!pages))
+		return NULL;
+
+	for (i = 0; i < udmabuf->pagecount; ++i)
+		pages[i] = folio_page(udmabuf->folios[i],
+				      udmabuf->offsets[i] >> PAGE_SHIFT);
+
+	vaddr = vmap(pages, udmabuf->pagecount, 0, PAGE_KERNEL);
+	WARN_ON(!vaddr);
+
+	kvfree(pages);
+	return vaddr;
+}
+
 static long udmabuf_vmap_test(struct file *filp, unsigned long arg)
 {
 	struct udmabuf_vmap uv;
@@ -563,7 +605,6 @@ static long udmabuf_vmap_test(struct file *filp, unsigned long arg)
 	bool can_page = true;
 	struct iosys_map map;
 	struct udmabuf *ubuf;
-	struct page **pages;
 	void *vaddr, *pvaddr;
 	struct file *file;
 	int ret = 0, i;
@@ -591,31 +632,18 @@ static long udmabuf_vmap_test(struct file *filp, unsigned long arg)
 	}
 
 	if (!can_page)
-		goto out_vaddr;
+		pvaddr = udmabuf_vmap_by_pfns(ubuf);
+	else
+		pvaddr = udmabuf_vmap_by_pages(ubuf);
 
-	pages = kvmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL);
-	if (WARN_ON(!pages)) {
-		ret = -ENOMEM;
+	if (!pvaddr)
 		goto out_vaddr;
-	}
-
-	for (i = 0; i < ubuf->pagecount; ++i)
-		pages[i] = folio_page(ubuf->folios[i],
-				      ubuf->offsets[i] >> PAGE_SHIFT);
-
-	pvaddr = vmap(pages, ubuf->pagecount, 0, PAGE_KERNEL);
-	if (WARN_ON(!pvaddr)) {
-		ret = -ENOMEM;
-		goto out_pages;
-	}
 
 	// compare if pages and pfns is same?
 	if (WARN_ON(memcmp(vaddr, pvaddr, ubuf->pagecount * PAGE_SIZE) != 0))
 		ret = -EINVAL;
 
 	vunmap(pvaddr);
-out_pages:
-	kvfree(pages);
 out_vaddr:
 	dma_buf_vunmap(dmabuf, &map);
 out:
-- 
2.48.1