* [PATCH v9 06/32] drm: exynos: use common helper for a scatterlist contiguity check
[not found] ` <CGME20200826063531eucas1p21c9277fe2a91e632e40822fb04a2c095@eucas1p2.samsung.com>
@ 2020-08-26 6:32 ` Marek Szyprowski
0 siblings, 0 replies; 2+ messages in thread
From: Marek Szyprowski @ 2020-08-26 6:32 UTC (permalink / raw)
To: dri-devel, iommu, linaro-mm-sig, linux-kernel
Cc: Marek Szyprowski, Christoph Hellwig, Robin Murphy,
Bartlomiej Zolnierkiewicz, linux-arm-kernel, David Airlie,
Daniel Vetter, Kukjin Kim, Krzysztof Kozlowski, Inki Dae,
Joonyoung Shim, Seung-Woo Kim, Kyungmin Park, linux-samsung-soc
Use common helper for checking the contiguity of the imported dma-buf.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by : Inki Dae <inki.dae@samsung.com>
---
drivers/gpu/drm/exynos/exynos_drm_gem.c | 23 +++--------------------
1 file changed, 3 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index efa476858db5..1716a023bca0 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -431,27 +431,10 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
{
struct exynos_drm_gem *exynos_gem;
- if (sgt->nents < 1)
+ /* check if the entries in the sg_table are contiguous */
+ if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+ DRM_ERROR("buffer chunks must be mapped contiguously");
return ERR_PTR(-EINVAL);
-
- /*
- * Check if the provided buffer has been mapped as contiguous
- * into DMA address space.
- */
- if (sgt->nents > 1) {
- dma_addr_t next_addr = sg_dma_address(sgt->sgl);
- struct scatterlist *s;
- unsigned int i;
-
- for_each_sg(sgt->sgl, s, sgt->nents, i) {
- if (!sg_dma_len(s))
- break;
- if (sg_dma_address(s) != next_addr) {
- DRM_ERROR("buffer chunks must be mapped contiguously");
- return ERR_PTR(-EINVAL);
- }
- next_addr = sg_dma_address(s) + sg_dma_len(s);
- }
}
exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v9 07/32] drm: exynos: fix common struct sg_table related issues
[not found] ` <CGME20200826063531eucas1p18dbb3c42b2ecc490360e7a75cf579af6@eucas1p1.samsung.com>
@ 2020-08-26 6:32 ` Marek Szyprowski
0 siblings, 0 replies; 2+ messages in thread
From: Marek Szyprowski @ 2020-08-26 6:32 UTC (permalink / raw)
To: dri-devel, iommu, linaro-mm-sig, linux-kernel
Cc: Marek Szyprowski, Christoph Hellwig, Robin Murphy,
Bartlomiej Zolnierkiewicz, linux-arm-kernel, David Airlie,
Daniel Vetter, Kukjin Kim, Krzysztof Kozlowski, Inki Dae,
Joonyoung Shim, Seung-Woo Kim, Kyungmin Park, linux-samsung-soc
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().
struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.
To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by : Inki Dae <inki.dae@samsung.com>
---
drivers/gpu/drm/exynos/exynos_drm_g2d.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index 03be31427181..967a5cdc120e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
@@ -395,8 +395,8 @@ static void g2d_userptr_put_dma_addr(struct g2d_data *g2d,
return;
out:
- dma_unmap_sg(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt->sgl,
- g2d_userptr->sgt->nents, DMA_BIDIRECTIONAL);
+ dma_unmap_sgtable(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt,
+ DMA_BIDIRECTIONAL, 0);
pages = frame_vector_pages(g2d_userptr->vec);
if (!IS_ERR(pages)) {
@@ -511,10 +511,10 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct g2d_data *g2d,
g2d_userptr->sgt = sgt;
- if (!dma_map_sg(to_dma_dev(g2d->drm_dev), sgt->sgl, sgt->nents,
- DMA_BIDIRECTIONAL)) {
+ ret = dma_map_sgtable(to_dma_dev(g2d->drm_dev), sgt,
+ DMA_BIDIRECTIONAL, 0);
+ if (ret) {
DRM_DEV_ERROR(g2d->dev, "failed to map sgt with dma region.\n");
- ret = -ENOMEM;
goto err_sg_free_table;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
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[not found] ` <CGME20200826063531eucas1p21c9277fe2a91e632e40822fb04a2c095@eucas1p2.samsung.com>
2020-08-26 6:32 ` [PATCH v9 06/32] drm: exynos: use common helper for a scatterlist contiguity check Marek Szyprowski
[not found] ` <CGME20200826063531eucas1p18dbb3c42b2ecc490360e7a75cf579af6@eucas1p1.samsung.com>
2020-08-26 6:32 ` [PATCH v9 07/32] drm: exynos: fix common struct sg_table related issues Marek Szyprowski
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