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From: Marek Szyprowski <m.szyprowski@samsung.com>
To: dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org,
	linux-kernel@vger.kernel.org
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
	Christoph Hellwig <hch@lst.de>,
	Robin Murphy <robin.murphy@arm.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	linux-arm-kernel@lists.infradead.org,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue,  5 May 2020 10:45:51 +0200	[thread overview]
Message-ID: <20200505084614.30424-2-m.szyprowski@samsung.com> (raw)
In-Reply-To: <20200505084614.30424-1-m.szyprowski@samsung.com>

The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of the entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. A common mistake was to ignore a result
of the dma_map_sg function and don't use the sg_table->orig_nents at all.

To avoid such issues, lets use common dma-mapping wrappers operating
directly on the struct sg_table objects and adjust references to the
nents and orig_nents respectively.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
---
 drivers/gpu/drm/drm_cache.c            |  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++-----
 drivers/gpu/drm/drm_prime.c            | 13 +++++++------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b0..63bd497 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ static void drm_cache_flush_clflush(struct page *pages[],
 		struct sg_page_iter sg_iter;
 
 		mb(); /*CLFLUSH is ordered only by using memory barriers*/
-		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
+		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
 			drm_clflush_page(sg_page_iter_page(&sg_iter));
 		mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index df31e57..cfcfc0d 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -117,8 +117,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 		kvfree(shmem->pages);
 	} else {
 		if (shmem->sgt) {
-			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-				     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+					  DMA_BIDIRECTIONAL);
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
@@ -395,8 +395,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
 	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-	dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-		     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL);
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
@@ -623,12 +622,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)
 		goto err_put_pages;
 	}
 	/* Map the pages for use by the h/w. */
-	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL);
+	if (ret)
+		goto err_free_sgt;
 
 	shmem->sgt = sgt;
 
 	return sgt;
 
+err_free_sgt:
+	sg_free_table(sgt);
+	kfree(sgt);
 err_put_pages:
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 282774e..3e7cb02 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct sg_table *sgt;
+	int ret;
 
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	else
 		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
+	ret = dma_map_sgtable_attrs(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret) {
 		sg_free_table(sgt);
 		kfree(sgt);
-		sgt = ERR_PTR(-ENOMEM);
+		sgt = ERR_PTR(ret);
 	}
 
 	return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 	if (!sgt)
 		return;
 
-	dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(sgt);
 }
@@ -975,7 +976,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 	 */
 	page_index = 0;
 	dma_index = 0;
-	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
+	for_each_sg(sgt->sgl, sg, sgt->orig_nents, count) {
 		page_len = sg->length;
 		page = sg_page(sg);
 		dma_len = sg_dma_len(sg);
-- 
1.9.1


WARNING: multiple messages have this Message-ID
From: Marek Szyprowski <m.szyprowski@samsung.com>
To: dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org,
	linux-kernel@vger.kernel.org
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Daniel Vetter <daniel@ffwll.ch>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue,  5 May 2020 10:45:51 +0200	[thread overview]
Message-ID: <20200505084614.30424-2-m.szyprowski@samsung.com> (raw)
In-Reply-To: <20200505084614.30424-1-m.szyprowski@samsung.com>

The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of the entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. A common mistake was to ignore a result
of the dma_map_sg function and don't use the sg_table->orig_nents at all.

To avoid such issues, lets use common dma-mapping wrappers operating
directly on the struct sg_table objects and adjust references to the
nents and orig_nents respectively.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
---
 drivers/gpu/drm/drm_cache.c            |  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++-----
 drivers/gpu/drm/drm_prime.c            | 13 +++++++------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b0..63bd497 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ static void drm_cache_flush_clflush(struct page *pages[],
 		struct sg_page_iter sg_iter;
 
 		mb(); /*CLFLUSH is ordered only by using memory barriers*/
-		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
+		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
 			drm_clflush_page(sg_page_iter_page(&sg_iter));
 		mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index df31e57..cfcfc0d 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -117,8 +117,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 		kvfree(shmem->pages);
 	} else {
 		if (shmem->sgt) {
-			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-				     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+					  DMA_BIDIRECTIONAL);
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
@@ -395,8 +395,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
 	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-	dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-		     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL);
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
@@ -623,12 +622,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)
 		goto err_put_pages;
 	}
 	/* Map the pages for use by the h/w. */
-	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL);
+	if (ret)
+		goto err_free_sgt;
 
 	shmem->sgt = sgt;
 
 	return sgt;
 
+err_free_sgt:
+	sg_free_table(sgt);
+	kfree(sgt);
 err_put_pages:
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 282774e..3e7cb02 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct sg_table *sgt;
+	int ret;
 
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	else
 		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
+	ret = dma_map_sgtable_attrs(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret) {
 		sg_free_table(sgt);
 		kfree(sgt);
-		sgt = ERR_PTR(-ENOMEM);
+		sgt = ERR_PTR(ret);
 	}
 
 	return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 	if (!sgt)
 		return;
 
-	dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(sgt);
 }
@@ -975,7 +976,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 	 */
 	page_index = 0;
 	dma_index = 0;
-	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
+	for_each_sg(sgt->sgl, sg, sgt->orig_nents, count) {
 		page_len = sg->length;
 		page = sg_page(sg);
 		dma_len = sg_dma_len(sg);
-- 
1.9.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID
From: Marek Szyprowski <m.szyprowski@samsung.com>
To: dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org,
	linux-kernel@vger.kernel.org
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Daniel Vetter <daniel@ffwll.ch>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue,  5 May 2020 10:45:51 +0200	[thread overview]
Message-ID: <20200505084614.30424-2-m.szyprowski@samsung.com> (raw)
In-Reply-To: <20200505084614.30424-1-m.szyprowski@samsung.com>

The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of the entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. A common mistake was to ignore a result
of the dma_map_sg function and don't use the sg_table->orig_nents at all.

To avoid such issues, lets use common dma-mapping wrappers operating
directly on the struct sg_table objects and adjust references to the
nents and orig_nents respectively.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
---
 drivers/gpu/drm/drm_cache.c            |  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++-----
 drivers/gpu/drm/drm_prime.c            | 13 +++++++------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b0..63bd497 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ static void drm_cache_flush_clflush(struct page *pages[],
 		struct sg_page_iter sg_iter;
 
 		mb(); /*CLFLUSH is ordered only by using memory barriers*/
-		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
+		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
 			drm_clflush_page(sg_page_iter_page(&sg_iter));
 		mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index df31e57..cfcfc0d 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -117,8 +117,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 		kvfree(shmem->pages);
 	} else {
 		if (shmem->sgt) {
-			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-				     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+					  DMA_BIDIRECTIONAL);
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
@@ -395,8 +395,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
 	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-	dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-		     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL);
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
@@ -623,12 +622,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)
 		goto err_put_pages;
 	}
 	/* Map the pages for use by the h/w. */
-	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL);
+	if (ret)
+		goto err_free_sgt;
 
 	shmem->sgt = sgt;
 
 	return sgt;
 
+err_free_sgt:
+	sg_free_table(sgt);
+	kfree(sgt);
 err_put_pages:
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 282774e..3e7cb02 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct sg_table *sgt;
+	int ret;
 
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	else
 		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
+	ret = dma_map_sgtable_attrs(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret) {
 		sg_free_table(sgt);
 		kfree(sgt);
-		sgt = ERR_PTR(-ENOMEM);
+		sgt = ERR_PTR(ret);
 	}
 
 	return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 	if (!sgt)
 		return;
 
-	dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(sgt);
 }
@@ -975,7 +976,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 	 */
 	page_index = 0;
 	dma_index = 0;
-	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
+	for_each_sg(sgt->sgl, sg, sgt->orig_nents, count) {
 		page_len = sg->length;
 		page = sg_page(sg);
 		dma_len = sg_dma_len(sg);
-- 
1.9.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID
From: Marek Szyprowski <m.szyprowski@samsung.com>
To: dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org,
	linux-kernel@vger.kernel.org
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	David Airlie <airlied@linux.ie>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-arm-kernel@lists.infradead.org,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues
Date: Tue,  5 May 2020 10:45:51 +0200	[thread overview]
Message-ID: <20200505084614.30424-2-m.szyprowski@samsung.com> (raw)
In-Reply-To: <20200505084614.30424-1-m.szyprowski@samsung.com>

The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of the entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. A common mistake was to ignore a result
of the dma_map_sg function and don't use the sg_table->orig_nents at all.

To avoid such issues, lets use common dma-mapping wrappers operating
directly on the struct sg_table objects and adjust references to the
nents and orig_nents respectively.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents
vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
---
 drivers/gpu/drm/drm_cache.c            |  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++-----
 drivers/gpu/drm/drm_prime.c            | 13 +++++++------
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b0..63bd497 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ static void drm_cache_flush_clflush(struct page *pages[],
 		struct sg_page_iter sg_iter;
 
 		mb(); /*CLFLUSH is ordered only by using memory barriers*/
-		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
+		for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0)
 			drm_clflush_page(sg_page_iter_page(&sg_iter));
 		mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index df31e57..cfcfc0d 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -117,8 +117,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 		kvfree(shmem->pages);
 	} else {
 		if (shmem->sgt) {
-			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-				     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+					  DMA_BIDIRECTIONAL);
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
@@ -395,8 +395,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
 	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-	dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-		     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL);
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
@@ -623,12 +622,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)
 		goto err_put_pages;
 	}
 	/* Map the pages for use by the h/w. */
-	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL);
+	if (ret)
+		goto err_free_sgt;
 
 	shmem->sgt = sgt;
 
 	return sgt;
 
+err_free_sgt:
+	sg_free_table(sgt);
+	kfree(sgt);
 err_put_pages:
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 282774e..3e7cb02 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct sg_table *sgt;
+	int ret;
 
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	else
 		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
+	ret = dma_map_sgtable_attrs(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret) {
 		sg_free_table(sgt);
 		kfree(sgt);
-		sgt = ERR_PTR(-ENOMEM);
+		sgt = ERR_PTR(ret);
 	}
 
 	return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 	if (!sgt)
 		return;
 
-	dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(sgt);
 }
@@ -975,7 +976,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 	 */
 	page_index = 0;
 	dma_index = 0;
-	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
+	for_each_sg(sgt->sgl, sg, sgt->orig_nents, count) {
 		page_len = sg->length;
 		page = sg_page(sg);
 		dma_len = sg_dma_len(sg);
-- 
1.9.1

_______________________________________________
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  parent reply	other threads:[~2020-05-05  8:46 UTC|newest]

Thread overview: 157+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200505084308eucas1p1aa040c3ae325a6c7d92f956b1f5aad0d@eucas1p1.samsung.com>
2020-05-05  8:43 ` [PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
2020-05-05  8:43   ` Marek Szyprowski
     [not found]   ` <CGME20200505084624eucas1p2a9a5c4d2aece2c1555a5480c19c2e050@eucas1p2.samsung.com>
2020-05-05  8:45     ` [PATCH v3 01/25] dma-mapping: add generic helpers for mapping sgtable objects Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
2020-05-05  8:45       ` Marek Szyprowski
     [not found]       ` <CGME20200505084625eucas1p1a3c25fd171f360e0aab2f76700699454@eucas1p1.samsung.com>
2020-05-05  8:45         ` Marek Szyprowski [this message]
2020-05-05  8:45           ` [PATCH v3 02/25] drm: core: fix common struct sg_table related issues Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05 10:15           ` Christoph Hellwig
2020-05-05 10:15             ` Christoph Hellwig
2020-05-05 10:15             ` Christoph Hellwig
2020-05-05 10:51             ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 10:51               ` Marek Szyprowski
2020-05-05 11:09               ` Christoph Hellwig
2020-05-05 11:09                 ` Christoph Hellwig
2020-05-05 11:09                 ` Christoph Hellwig
2020-05-08  7:12                 ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:12                   ` Marek Szyprowski
2020-05-08  7:16                   ` Christoph Hellwig
2020-05-08  7:16                     ` Christoph Hellwig
2020-05-08  7:16                     ` Christoph Hellwig
2020-05-12  9:05                     ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
2020-05-12  9:05                       ` Marek Szyprowski
     [not found]       ` <CGME20200505084625eucas1p2b8ca16ff91ba9d6655f525ef85915d00@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 03/25] drm: amdgpu: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084626eucas1p20753456727333c09718253ca5c32d98c@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 04/25] drm: armada: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084626eucas1p20abe79e406f60ae92fec252072befc5a@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 05/25] drm: etnaviv: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084627eucas1p119c77fbf28532627f27382efc51b0aaa@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 06/25] drm: exynos: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084627eucas1p199eed52198b4409da1fa8e2256f5bb62@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 07/25] drm: i915: " Marek Szyprowski
2020-05-05  8:45           ` [Intel-gfx] " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084628eucas1p2c87aae2f471b716675559debbf680c46@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 08/25] drm: lima: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084629eucas1p12e882329da88edd155ba9f9f952889a0@eucas1p1.samsung.com>
2020-05-05  8:45         ` [PATCH v3 09/25] drm: msm: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
     [not found]       ` <CGME20200505084629eucas1p23d2d6a53451e67e2b0a3544eb696008b@eucas1p2.samsung.com>
2020-05-05  8:45         ` [PATCH v3 10/25] drm: panfrost: " Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-05  8:45           ` Marek Szyprowski
2020-05-11 15:51           ` Steven Price
2020-05-11 15:51             ` Steven Price
2020-05-11 15:51             ` Steven Price
2020-05-11 15:51             ` Steven Price
     [not found]       ` <CGME20200505084630eucas1p1c74cd5d287e1080b85d98edde405a577@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 11/25] drm: radeon: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084630eucas1p2199401486591b681b84a4b24496295fb@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 12/25] drm: rockchip: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084631eucas1p11121f9373a1d282f0262d1faa33f35fb@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 13/25] drm: tegra: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084632eucas1p2e37c536205c057984c5f0355f6ffe1c2@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 14/25] drm: virtio: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084632eucas1p231212e9cea88e755da8eaf1fb012d2c6@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 15/25] drm: vmwgfx: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-12  0:19           ` [Linux-graphics-maintainer] " Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
2020-05-12  0:19             ` Roland Scheidegger
     [not found]       ` <CGME20200505084633eucas1p26a6a3f44c64955aadec834bed027e522@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 16/25] xen: gntdev: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084633eucas1p19798e1fb42c9430a93d668bc585e58da@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 17/25] drm: host1x: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084634eucas1p1e0ea160dd77afbf6d2f7e6154ded40d0@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 18/25] drm: rcar-du: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  9:24           ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
2020-05-05  9:24             ` Geert Uytterhoeven
     [not found]       ` <CGME20200505084634eucas1p105456f28d9a7935190478546e566975f@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 19/25] dmabuf: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084635eucas1p14800a1e2598364d168adecd57b94225c@eucas1p1.samsung.com>
2020-05-05  8:46         ` [PATCH v3 20/25] staging: ion: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084636eucas1p23a33d0b83ca284692713745d004f93ea@eucas1p2.samsung.com>
     [not found]         ` <20200505084614.30424-1-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2020-05-05  8:46           ` [PATCH v3 21/25] staging: tegra-vde: " Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
2020-05-05  8:46             ` Marek Szyprowski
     [not found]       ` <CGME20200505084637eucas1p20390fa3c010bde00e438cce1b48d209c@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 22/25] misc: fastrpc: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084637eucas1p2c6d4b880698e8db97a8a9468692befe1@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 23/25] rapidio: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084638eucas1p24f356b441a3589e9528d239c0b9ac666@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 24/25] samples: vfio-mdev/mbochs: " Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
     [not found]       ` <CGME20200505084638eucas1p2d4add214063543248d81c0977e3f1823@eucas1p2.samsung.com>
2020-05-05  8:46         ` [PATCH v3 25/25] media: pci: fix common ALSA DMA-mapping related codes Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05  8:46           ` Marek Szyprowski
2020-05-05 10:22       ` [PATCH v3 01/25] dma-mapping: add generic helpers for mapping sgtable objects Christoph Hellwig
2020-05-05 10:22         ` Christoph Hellwig
2020-05-05 10:22         ` Christoph Hellwig
2020-05-05 10:44         ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-05 10:44           ` Marek Szyprowski
2020-05-07  8:47       ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil
2020-05-07  8:47         ` Hans Verkuil

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