From: Rob Clark <robdclark@gmail.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: dri-devel <dri-devel@lists.freedesktop.org>,
"list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>,
Joerg Roedel <joro@8bytes.org>,"
<iommu@lists.linux-foundation.org>,
linaro-mm-sig@lists.linaro.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Christoph Hellwig <hch@lst.de>,
Robin Murphy <robin.murphy@arm.com>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Sean Paul <sean@poorly.run>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
freedreno <freedreno@lists.freedesktop.org>
Subject: Re: [PATCH v7 13/36] drm: msm: fix common struct sg_table related issues
Date: Fri, 19 Jun 2020 07:45:32 -0700 [thread overview]
Message-ID: <CAF6AEGv9We+wD72_px3mucsXQuTFZ3ZX_CAA1LTysMBdiDcEFw@mail.gmail.com> (raw)
In-Reply-To: <20200619103636.11974-14-m.szyprowski@samsung.com>
On Fri, Jun 19, 2020 at 3:37 AM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> 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>
Acked-by: Rob Clark <robdclark@gmail.com>
(let me know if you want me to take this one in via msm-next or if the
plan is to take the series via drm-misc)
> ---
> drivers/gpu/drm/msm/msm_gem.c | 13 +++++--------
> drivers/gpu/drm/msm/msm_gpummu.c | 14 ++++++--------
> drivers/gpu/drm/msm/msm_iommu.c | 2 +-
> 3 files changed, 12 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index 38b0c0e1f83e..e0d5fd36ea8f 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -53,11 +53,10 @@ static void sync_for_device(struct msm_gem_object *msm_obj)
> struct device *dev = msm_obj->base.dev->dev;
>
> if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
> - dma_sync_sg_for_device(dev, msm_obj->sgt->sgl,
> - msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
> + dma_sync_sgtable_for_device(dev, msm_obj->sgt,
> + DMA_BIDIRECTIONAL);
> } else {
> - dma_map_sg(dev, msm_obj->sgt->sgl,
> - msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
> + dma_map_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
> }
> }
>
> @@ -66,11 +65,9 @@ static void sync_for_cpu(struct msm_gem_object *msm_obj)
> struct device *dev = msm_obj->base.dev->dev;
>
> if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
> - dma_sync_sg_for_cpu(dev, msm_obj->sgt->sgl,
> - msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
> + dma_sync_sgtable_for_cpu(dev, msm_obj->sgt, DMA_BIDIRECTIONAL);
> } else {
> - dma_unmap_sg(dev, msm_obj->sgt->sgl,
> - msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
> + dma_unmap_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
> }
> }
>
> diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
> index 310a31b05faa..319f06c28235 100644
> --- a/drivers/gpu/drm/msm/msm_gpummu.c
> +++ b/drivers/gpu/drm/msm/msm_gpummu.c
> @@ -30,21 +30,19 @@ static int msm_gpummu_map(struct msm_mmu *mmu, uint64_t iova,
> {
> struct msm_gpummu *gpummu = to_msm_gpummu(mmu);
> unsigned idx = (iova - GPUMMU_VA_START) / GPUMMU_PAGE_SIZE;
> - struct scatterlist *sg;
> + struct sg_dma_page_iter dma_iter;
> unsigned prot_bits = 0;
> - unsigned i, j;
>
> if (prot & IOMMU_WRITE)
> prot_bits |= 1;
> if (prot & IOMMU_READ)
> prot_bits |= 2;
>
> - for_each_sg(sgt->sgl, sg, sgt->nents, i) {
> - dma_addr_t addr = sg->dma_address;
> - for (j = 0; j < sg->length / GPUMMU_PAGE_SIZE; j++, idx++) {
> - gpummu->table[idx] = addr | prot_bits;
> - addr += GPUMMU_PAGE_SIZE;
> - }
> + for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
> + dma_addr_t addr = sg_page_iter_dma_address(&dma_iter);
> +
> + BUILD_BUG_ON(GPUMMU_PAGE_SIZE != PAGE_SIZE);
> + gpummu->table[idx++] = addr | prot_bits;
> }
>
> /* we can improve by deferring flush for multiple map() */
> diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> index 3a381a9674c9..6c31e65834c6 100644
> --- a/drivers/gpu/drm/msm/msm_iommu.c
> +++ b/drivers/gpu/drm/msm/msm_iommu.c
> @@ -36,7 +36,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
> struct msm_iommu *iommu = to_msm_iommu(mmu);
> size_t ret;
>
> - ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
> + ret = iommu_map_sgtable(iommu->domain, iova, sgt, prot);
> WARN_ON(!ret);
>
> return (ret == len) ? 0 : -EINVAL;
> --
> 2.17.1
>
next prev parent reply other threads:[~2020-06-19 16:41 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200619103652eucas1p203d684adff0faa672ff5c8d383b52f23@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 00/36] DRM: fix struct sg_table nents vs. orig_nents misuse Marek Szyprowski
[not found] ` <CGME20200619103653eucas1p2542a7f42db61b22a43919666368dbbfa@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 01/36] drm: prime: add common helper to check scatterlist contiguity Marek Szyprowski
2020-07-07 14:30 ` Andrzej Hajda
2020-07-07 15:03 ` Andrzej Hajda
[not found] ` <CGME20200619103654eucas1p227a1d6926d008ef21ba4e0b68a8de210@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 02/36] drm: prime: use sgtable iterators in drm_prime_sg_to_page_addr_arrays() Marek Szyprowski
2020-07-07 14:41 ` Andrzej Hajda
[not found] ` <CGME20200619103655eucas1p1b01cbe67526e2b2f8254eb20ccac1858@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 03/36] drm: core: fix common struct sg_table related issues Marek Szyprowski
2020-07-07 15:02 ` Andrzej Hajda
[not found] ` <CGME20200619103655eucas1p28ea4bf59428550217c8962666d6f077b@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 04/36] drm: amdgpu: " Marek Szyprowski
2020-06-22 13:27 ` Christian König
2020-07-07 13:06 ` Marek Szyprowski
[not found] ` <CGME20200619103656eucas1p262a08b701244745a547a0c38f26f83af@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 05/36] drm: armada: " Marek Szyprowski
[not found] ` <CGME20200619103657eucas1p2b7cec8f7b477c9574e2594ad6644a780@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 06/36] drm: etnaviv: " Marek Szyprowski
[not found] ` <CGME20200619103657eucas1p24bff92408adbd4715130fb47595a6187@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 07/36] drm: exynos: use common helper for a scatterlist contiguity check Marek Szyprowski
2020-07-07 9:35 ` Andrzej Hajda
2020-07-07 15:04 ` Andrzej Hajda
2020-07-14 0:28 ` Inki Dae
[not found] ` <CGME20200619103658eucas1p1c3236e2de2798c2d8c02279a9263e9a9@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 08/36] drm: exynos: fix common struct sg_table related issues Marek Szyprowski
2020-07-07 9:40 ` Andrzej Hajda
2020-07-07 15:05 ` Andrzej Hajda
2020-07-14 0:27 ` Inki Dae
[not found] ` <CGME20200619103659eucas1p27ece9865ea4cdd82d4ca4df06edef7e6@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 09/36] drm: i915: " Marek Szyprowski
[not found] ` <CGME20200619103659eucas1p15d57f701ea85df16e953bfd5098423f6@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 10/36] drm: lima: " Marek Szyprowski
[not found] ` <CGME20200619103700eucas1p13747c6a4d1a89f3cfc94a585ada9be4b@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 11/36] drm: mediatek: use common helper for a scatterlist contiguity check Marek Szyprowski
[not found] ` <CGME20200619103701eucas1p2323797b812f4d8c28e851aa80938a8dc@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 12/36] drm: mediatek: use common helper for extracting pages array Marek Szyprowski
[not found] ` <CGME20200619103702eucas1p1c57147013bbac3968f6ba073caec68b5@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 13/36] drm: msm: fix common struct sg_table related issues Marek Szyprowski
2020-06-19 14:45 ` Rob Clark [this message]
[not found] ` <CGME20200619103702eucas1p207b9cacc7460a334a0eda58c2b60a965@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 14/36] drm: omapdrm: use common helper for extracting pages array Marek Szyprowski
[not found] ` <CGME20200619103703eucas1p14faa1cec371efb0bf98ae696d58da64d@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 15/36] drm: omapdrm: fix common struct sg_table related issues Marek Szyprowski
[not found] ` <CGME20200619103703eucas1p2b8b0e90f9559c3fff12d61f76b861cc1@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 16/36] drm: panfrost: " Marek Szyprowski
[not found] ` <CGME20200619103704eucas1p1bf233e8914507323499186d9ab742c09@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 17/36] drm: radeon: " Marek Szyprowski
[not found] ` <CGME20200619103705eucas1p2d81a91b989d5aed5c7da6897173905cd@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 18/36] drm: rockchip: use common helper for a scatterlist contiguity check Marek Szyprowski
[not found] ` <CGME20200619103706eucas1p24f226bc00559f0812bc44d7933acd1e4@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 19/36] drm: rockchip: fix common struct sg_table related issues Marek Szyprowski
[not found] ` <CGME20200619103706eucas1p2b9a9926941e812db1111ec46a97695cd@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 20/36] drm: tegra: " Marek Szyprowski
[not found] ` <CGME20200619103707eucas1p1cdb34a10d5657bdd62fdf51fb7bf0146@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 21/36] drm: v3d: " Marek Szyprowski
[not found] ` <CGME20200619103708eucas1p2207ebc9373b820797675b91060a2a597@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 22/36] drm: virtio: " Marek Szyprowski
[not found] ` <CGME20200619103708eucas1p230ca99e915e759bc0e93cd844c91b311@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 23/36] drm: vmwgfx: " Marek Szyprowski
[not found] ` <CGME20200619103709eucas1p12c32fa6377caf78e5dc28ce0ff51e7a0@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 24/36] drm: xen: " Marek Szyprowski
[not found] ` <CGME20200619103710eucas1p1873c8ebb37e6717a5864c31d10b50efd@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 25/36] xen: gntdev: " Marek Szyprowski
[not found] ` <CGME20200619103710eucas1p1160d521b10c9afdb8e447e261072bfd4@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 26/36] drm: host1x: " Marek Szyprowski
2020-06-21 14:47 ` kernel test robot
[not found] ` <CGME20200619103711eucas1p188e07cb9aaad13d39238aac4fe84b10c@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 27/36] drm: rcar-du: " Marek Szyprowski
[not found] ` <CGME20200619103712eucas1p1a29d1fe41061ed5b138a9cdd5d811419@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 28/36] dmabuf: " Marek Szyprowski
[not found] ` <CGME20200619103713eucas1p2f4b6b66a376a72d1bf62ea6d92572045@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 29/36] staging: ion: remove dead code Marek Szyprowski
[not found] ` <CGME20200619103714eucas1p2bfc6c1d97d7913ad5988e3aaef8cc5ff@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 30/36] staging: ion: fix common struct sg_table related issues Marek Szyprowski
[not found] ` <CGME20200619103714eucas1p18db6efd1a380fc0bdb16174ee85036fa@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 31/36] staging: tegra-vde: " Marek Szyprowski
2020-06-20 21:10 ` kernel test robot
2020-06-21 4:00 ` Dmitry Osipenko
2020-06-30 10:07 ` Marek Szyprowski
2020-07-01 1:45 ` Dmitry Osipenko
[not found] ` <CGME20200619103715eucas1p12d01355499fbecb8632472b1b8230e6f@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 32/36] misc: fastrpc: " Marek Szyprowski
[not found] ` <CGME20200619103716eucas1p1b7c50f7b421fb29829050b9355e3e644@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 33/36] rapidio: " Marek Szyprowski
2020-06-21 1:23 ` kernel test robot
2020-06-23 15:46 ` [kbuild] " Dan Carpenter
[not found] ` <CGME20200630084445eucas1p1e85857b5d046648578f1447f8ba521a5@eucas1p1.samsung.com>
2020-06-30 8:44 ` [PATCH v8] " Marek Szyprowski
[not found] ` <CGME20200619103716eucas1p28d6da172346acf044d3c1f213d9543ef@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 34/36] samples: vfio-mdev/mbochs: " Marek Szyprowski
[not found] ` <CGME20200619103717eucas1p23b82366794c92cc70c0492e4ca29c4a1@eucas1p2.samsung.com>
2020-06-19 10:36 ` [PATCH v7 35/36] media: pci: fix common ALSA DMA-mapping related codes Marek Szyprowski
[not found] ` <CGME20200619103718eucas1p11cd577b435672197f48bfcba2d06bc18@eucas1p1.samsung.com>
2020-06-19 10:36 ` [PATCH v7 36/36] videobuf2: use sgtable-based scatterlist wrappers Marek Szyprowski
[not found] ` <CGME20200630104527eucas1p13f19c24ff053556fb1fa7dc72be14c77@eucas1p1.samsung.com>
2020-06-30 10:45 ` [PATCH v8] " Marek Szyprowski
2020-06-30 8:49 ` [PATCH v7 00/36] DRM: fix struct sg_table nents vs. orig_nents misuse Marek Szyprowski
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