linux-kernel - [etnaviv-next v2 3/3] drm/etnaviv: Improve VA, PA, SIZE alignment checking

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Message-Id: <20241104200354.656525-4-sui.jingfeng@linux.dev>
Date: Tue,  5 Nov 2024 04:03:54 +0800
From: Sui Jingfeng <sui.jingfeng@...ux.dev>
To: Lucas Stach <l.stach@...gutronix.de>,
	Russell King <linux+etnaviv@...linux.org.uk>,
	Christian Gmeiner <christian.gmeiner@...il.com>
Cc: David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	etnaviv@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Sui Jingfeng <sui.jingfeng@...ux.dev>
Subject: [etnaviv-next v2 3/3] drm/etnaviv: Improve VA, PA, SIZE alignment checking

We only need checking the alignment on the upper caller function, if those
address and/or sizes are pass the check. Those address will certainly pass
the same test under the etnaviv_context_unmap() function.

Remove redundant alignment tests in etnaviv_context_unmap() and move the
alignment tests to the upper caller etnaviv_iommu_map() function. Which
reduce some extra overhead.

Signed-off-by: Sui Jingfeng <sui.jingfeng@...ux.dev>
---
 drivers/gpu/drm/etnaviv/etnaviv_mmu.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index 05021848126e..56ae2de76e15 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -19,12 +19,6 @@ static void etnaviv_context_unmap(struct etnaviv_iommu_context *context,
 	size_t unmapped_page, unmapped = 0;
 	size_t pgsize = SZ_4K;
 
-	if (!IS_ALIGNED(iova | size, pgsize)) {
-		pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%zx\n",
-		       iova, size, pgsize);
-		return;
-	}
-
 	while (unmapped < size) {
 		unmapped_page = context->global->ops->unmap(context, iova,
 							    pgsize);
@@ -45,12 +39,6 @@ static int etnaviv_context_map(struct etnaviv_iommu_context *context,
 	size_t orig_size = size;
 	int ret = 0;
 
-	if (!IS_ALIGNED(iova | paddr | size, pgsize)) {
-		pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%zx\n",
-		       iova, &paddr, size, pgsize);
-		return -EINVAL;
-	}
-
 	while (size) {
 		ret = context->global->ops->map(context, iova, paddr, pgsize,
 						prot);
@@ -88,6 +76,14 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context *context,
 
 		VERB("map[%d]: %08x %pap(%x)", i, da, &pa, bytes);
 
+		if (!IS_ALIGNED(iova | pa | bytes, SZ_4K)) {
+			dev_err(context->global->dev,
+				"unaligned: iova 0x%x pa %pa size 0x%x\n",
+				iova, &pa, bytes);
+			ret = -EINVAL;
+			goto fail;
+		}
+
 		ret = etnaviv_context_map(context, da, pa, bytes, prot);
 		if (ret)
 			goto fail;
-- 
2.34.1