| Message ID | 20200512090058.14910-38-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DRM: fix struct sg_table nents vs. orig_nents misuse | expand |
>-----Original Message----- >From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of >Marek Szyprowski >Sent: Tuesday, May 12, 2020 5:01 AM >To: dri-devel@lists.freedesktop.org; iommu@lists.linux-foundation.org; >linaro-mm-sig@lists.linaro.org; linux-kernel@vger.kernel.org >Cc: Pawel Osciak <pawel@osciak.com>; Bartlomiej Zolnierkiewicz ><b.zolnierkie@samsung.com>; David Airlie <airlied@linux.ie>; linux- >media@vger.kernel.org; Hans Verkuil <hverkuil-cisco@xs4all.nl>; Mauro >Carvalho Chehab <mchehab@kernel.org>; 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 v4 38/38] videobuf2: use sgtable-based scatterlist wrappers > >Use recently introduced common wrappers operating directly on the struct >sg_table objects and scatterlist page iterators to make the code a bit >more compact, robust, easier to follow and copy/paste safe. > >No functional change, because the code already properly did all the >scaterlist related calls. > >Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >--- >For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents >vs. orig_nents misuse' thread: >https://lore.kernel.org/dri-devel/20200512085710.14688-1- >m.szyprowski@samsung.com/T/ >--- > .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++---- >-------- > drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++-------- >-- > drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++---- > 3 files changed, 34 insertions(+), 51 deletions(-) > >diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >index d3a3ee5..bf31a9d 100644 >--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >@@ -48,16 +48,15 @@ struct vb2_dc_buf { > > static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) > { >- struct scatterlist *s; > dma_addr_t expected = sg_dma_address(sgt->sgl); >- unsigned int i; >+ struct sg_dma_page_iter dma_iter; > unsigned long size = 0; > >- for_each_sg(sgt->sgl, s, sgt->nents, i) { >- if (sg_dma_address(s) != expected) >+ for_each_sgtable_dma_page(sgt, &dma_iter, 0) { >+ if (sg_page_iter_dma_address(&dma_iter) != expected) > break; >- expected = sg_dma_address(s) + sg_dma_len(s); >- size += sg_dma_len(s); >+ expected += PAGE_SIZE; >+ size += PAGE_SIZE; This code in drm_prime_t_contiguous_size and here. I seem to remember seeing the same pattern in other drivers. Would it worthwhile to make this a helper as well? Also, isn't the sg_dma_len() the actual length of the chunk we are looking at? If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your loop/calculation still work? Thanks, Mike > } > return size; > } >@@ -99,8 +98,7 @@ static void vb2_dc_prepare(void *buf_priv) > if (!sgt || buf->db_attach) > return; > >- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir); >+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); > } > > static void vb2_dc_finish(void *buf_priv) >@@ -112,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv) > if (!sgt || buf->db_attach) > return; > >- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf- >>dma_dir); >+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); > } > > /*********************************************/ >@@ -273,8 +271,8 @@ static void vb2_dc_dmabuf_ops_detach(struct >dma_buf *dbuf, > * memory locations do not require any explicit cache > * maintenance prior or after being used by the device. > */ >- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt- >>orig_nents, >- attach->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC); > sg_free_table(sgt); > kfree(attach); > db_attach->priv = NULL; >@@ -299,8 +297,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( > > /* release any previous cache */ > if (attach->dma_dir != DMA_NONE) { >- dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt- >>orig_nents, >- attach->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC); > attach->dma_dir = DMA_NONE; > } > >@@ -308,9 +306,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( > * mapping to the client with new direction, no cache sync > * required see comment in vb2_dc_dmabuf_ops_detach() > */ >- sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt- >>orig_nents, >- dma_dir, DMA_ATTR_SKIP_CPU_SYNC); >- if (!sgt->nents) { >+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC)) { > pr_err("failed to map scatterlist\n"); > mutex_unlock(lock); > return ERR_PTR(-EIO); >@@ -423,8 +420,8 @@ static void vb2_dc_put_userptr(void *buf_priv) > * No need to sync to CPU, it's already synced to the CPU > * since the finish() memop will have been called before this. > */ >- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC); > pages = frame_vector_pages(buf->vec); > /* sgt should exist only if vector contains pages... */ > BUG_ON(IS_ERR(pages)); >@@ -521,9 +518,8 @@ static void *vb2_dc_get_userptr(struct device *dev, >unsigned long vaddr, > * No need to sync to the device, this will happen later when the > * prepare() memop is called. > */ >- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >- if (sgt->nents <= 0) { >+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC)) { > pr_err("failed to map scatterlist\n"); > ret = -EIO; > goto fail_sgt_init; >@@ -545,8 +541,7 @@ static void *vb2_dc_get_userptr(struct device *dev, >unsigned long vaddr, > return buf; > > fail_map_sg: >- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); > > fail_sgt_init: > sg_free_table(sgt); >diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c >b/drivers/media/common/videobuf2/videobuf2-dma-sg.c >index 92072a0..6ddf953 100644 >--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c >+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c >@@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, >unsigned long dma_attrs, > * No need to sync to the device, this will happen later when the > * prepare() memop is called. > */ >- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >- if (!sgt->nents) >+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC)) { > goto fail_map; > > buf->handler.refcount = &buf->refcount; >@@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv) > if (refcount_dec_and_test(&buf->refcount)) { > dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, > buf->num_pages); >- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC); > if (buf->vaddr) > vm_unmap_ram(buf->vaddr, buf->num_pages); > sg_free_table(buf->dma_sgt); >@@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv) > if (buf->db_attach) > return; > >- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir); >+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); > } > > static void vb2_dma_sg_finish(void *buf_priv) >@@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv) > if (buf->db_attach) > return; > >- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf- >>dma_dir); >+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); > } > > static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long >vaddr, >@@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device >*dev, unsigned long vaddr, > * No need to sync to the device, this will happen later when the > * prepare() memop is called. > */ >- sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, >- buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); >- if (!sgt->nents) >+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, >+ DMA_ATTR_SKIP_CPU_SYNC)) { > goto userptr_fail_map; > > return buf; >@@ -286,8 +283,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) > > dprintk(1, "%s: Releasing userspace buffer of %d pages\n", > __func__, buf->num_pages); >- dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf- >>dma_dir, >- DMA_ATTR_SKIP_CPU_SYNC); >+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, >DMA_ATTR_SKIP_CPU_SYNC); > if (buf->vaddr) > vm_unmap_ram(buf->vaddr, buf->num_pages); > sg_free_table(buf->dma_sgt); >@@ -410,8 +406,7 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct >dma_buf *dbuf, > > /* release the scatterlist cache */ > if (attach->dma_dir != DMA_NONE) >- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- attach->dma_dir); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir); > sg_free_table(sgt); > kfree(attach); > db_attach->priv = NULL; >@@ -436,15 +431,12 @@ static struct sg_table >*vb2_dma_sg_dmabuf_ops_map( > > /* release any previous cache */ > if (attach->dma_dir != DMA_NONE) { >- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- attach->dma_dir); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir); > attach->dma_dir = DMA_NONE; > } > > /* mapping to the client with new direction */ >- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- dma_dir); >- if (!sgt->nents) { >+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) { > pr_err("failed to map scatterlist\n"); > mutex_unlock(lock); > return ERR_PTR(-EIO); >diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c >b/drivers/media/common/videobuf2/videobuf2-vmalloc.c >index c66fda4..bf5ac63 100644 >--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c >+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c >@@ -229,7 +229,7 @@ static int vb2_vmalloc_dmabuf_ops_attach(struct >dma_buf *dbuf, > kfree(attach); > return ret; > } >- for_each_sg(sgt->sgl, sg, sgt->nents, i) { >+ for_each_sgtable_sg(sgt, sg, i) { > struct page *page = vmalloc_to_page(vaddr); > > if (!page) { >@@ -259,8 +259,7 @@ static void vb2_vmalloc_dmabuf_ops_detach(struct >dma_buf *dbuf, > > /* release the scatterlist cache */ > if (attach->dma_dir != DMA_NONE) >- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- attach->dma_dir); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, >0); > sg_free_table(sgt); > kfree(attach); > db_attach->priv = NULL; >@@ -285,15 +284,12 @@ static struct sg_table >*vb2_vmalloc_dmabuf_ops_map( > > /* release any previous cache */ > if (attach->dma_dir != DMA_NONE) { >- dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- attach->dma_dir); >+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, >0); > attach->dma_dir = DMA_NONE; > } > > /* mapping to the client with new direction */ >- sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, >- dma_dir); >- if (!sgt->nents) { >+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) { > pr_err("failed to map scatterlist\n"); > mutex_unlock(lock); > return ERR_PTR(-EIO); >-- >1.9.1 > >_______________________________________________ >dri-devel mailing list >dri-devel@lists.freedesktop.org >https://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi Michael, On 12.05.2020 19:52, Ruhl, Michael J wrote: >> -----Original Message----- >> From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of >> Marek Szyprowski >> Sent: Tuesday, May 12, 2020 5:01 AM >> To: dri-devel@lists.freedesktop.org; iommu@lists.linux-foundation.org; >> linaro-mm-sig@lists.linaro.org; linux-kernel@vger.kernel.org >> Cc: Pawel Osciak <pawel@osciak.com>; Bartlomiej Zolnierkiewicz >> <b.zolnierkie@samsung.com>; David Airlie <airlied@linux.ie>; linux- >> media@vger.kernel.org; Hans Verkuil <hverkuil-cisco@xs4all.nl>; Mauro >> Carvalho Chehab <mchehab@kernel.org>; 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 v4 38/38] videobuf2: use sgtable-based scatterlist wrappers >> >> Use recently introduced common wrappers operating directly on the struct >> sg_table objects and scatterlist page iterators to make the code a bit >> more compact, robust, easier to follow and copy/paste safe. >> >> No functional change, because the code already properly did all the >> scaterlist related calls. >> >> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >> --- >> For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents >> vs. orig_nents misuse' thread: >> https://lore.kernel.org/dri-devel/20200512085710.14688-1- >> m.szyprowski@samsung.com/T/ >> --- >> .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++---- >> -------- >> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++-------- >> -- >> drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++---- >> 3 files changed, 34 insertions(+), 51 deletions(-) >> >> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >> b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >> index d3a3ee5..bf31a9d 100644 >> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >> @@ -48,16 +48,15 @@ struct vb2_dc_buf { >> >> static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) >> { >> - struct scatterlist *s; >> dma_addr_t expected = sg_dma_address(sgt->sgl); >> - unsigned int i; >> + struct sg_dma_page_iter dma_iter; >> unsigned long size = 0; >> >> - for_each_sg(sgt->sgl, s, sgt->nents, i) { >> - if (sg_dma_address(s) != expected) >> + for_each_sgtable_dma_page(sgt, &dma_iter, 0) { >> + if (sg_page_iter_dma_address(&dma_iter) != expected) >> break; >> - expected = sg_dma_address(s) + sg_dma_len(s); >> - size += sg_dma_len(s); >> + expected += PAGE_SIZE; >> + size += PAGE_SIZE; > This code in drm_prime_t_contiguous_size and here. I seem to remember seeing > the same pattern in other drivers. > > Would it worthwhile to make this a helper as well? I think I've identified such patterns in all DRM drivers and replaced with a common helper. So far I have no idea where to put such helper to make it available for media/videobuf2, so those a few lines are indeed duplicated here. > Also, isn't the sg_dma_len() the actual length of the chunk we are looking at? > > If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your loop/calculation still work? scaterlist page iterators (for_each_sg_page/for_each_sg_dma_page and their sgtable variants) always operates on PAGE_SIZE units. They correctly handle larger sg_dma_len(). Best regards
>-----Original Message----- >From: Marek Szyprowski <m.szyprowski@samsung.com> >Sent: Tuesday, May 12, 2020 4:34 PM >To: Ruhl, Michael J <michael.j.ruhl@intel.com>; dri- >devel@lists.freedesktop.org; iommu@lists.linux-foundation.org; linaro-mm- >sig@lists.linaro.org; linux-kernel@vger.kernel.org >Cc: Pawel Osciak <pawel@osciak.com>; Bartlomiej Zolnierkiewicz ><b.zolnierkie@samsung.com>; David Airlie <airlied@linux.ie>; linux- >media@vger.kernel.org; Hans Verkuil <hverkuil-cisco@xs4all.nl>; Mauro >Carvalho Chehab <mchehab@kernel.org>; Robin Murphy ><robin.murphy@arm.com>; Christoph Hellwig <hch@lst.de>; linux-arm- >kernel@lists.infradead.org >Subject: Re: [PATCH v4 38/38] videobuf2: use sgtable-based scatterlist >wrappers > >Hi Michael, > >On 12.05.2020 19:52, Ruhl, Michael J wrote: >>> -----Original Message----- >>> From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of >>> Marek Szyprowski >>> Sent: Tuesday, May 12, 2020 5:01 AM >>> To: dri-devel@lists.freedesktop.org; iommu@lists.linux-foundation.org; >>> linaro-mm-sig@lists.linaro.org; linux-kernel@vger.kernel.org >>> Cc: Pawel Osciak <pawel@osciak.com>; Bartlomiej Zolnierkiewicz >>> <b.zolnierkie@samsung.com>; David Airlie <airlied@linux.ie>; linux- >>> media@vger.kernel.org; Hans Verkuil <hverkuil-cisco@xs4all.nl>; Mauro >>> Carvalho Chehab <mchehab@kernel.org>; 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 v4 38/38] videobuf2: use sgtable-based scatterlist >wrappers >>> >>> Use recently introduced common wrappers operating directly on the struct >>> sg_table objects and scatterlist page iterators to make the code a bit >>> more compact, robust, easier to follow and copy/paste safe. >>> >>> No functional change, because the code already properly did all the >>> scaterlist related calls. >>> >>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >>> --- >>> For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents >>> vs. orig_nents misuse' thread: >>> https://lore.kernel.org/dri-devel/20200512085710.14688-1- >>> m.szyprowski@samsung.com/T/ >>> --- >>> .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++- >--- >>> -------- >>> drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++----- >--- >>> -- >>> drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++---- >>> 3 files changed, 34 insertions(+), 51 deletions(-) >>> >>> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >>> b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >>> index d3a3ee5..bf31a9d 100644 >>> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c >>> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c >>> @@ -48,16 +48,15 @@ struct vb2_dc_buf { >>> >>> static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) >>> { >>> - struct scatterlist *s; >>> dma_addr_t expected = sg_dma_address(sgt->sgl); >>> - unsigned int i; >>> + struct sg_dma_page_iter dma_iter; >>> unsigned long size = 0; >>> >>> - for_each_sg(sgt->sgl, s, sgt->nents, i) { >>> - if (sg_dma_address(s) != expected) >>> + for_each_sgtable_dma_page(sgt, &dma_iter, 0) { >>> + if (sg_page_iter_dma_address(&dma_iter) != expected) >>> break; >>> - expected = sg_dma_address(s) + sg_dma_len(s); >>> - size += sg_dma_len(s); >>> + expected += PAGE_SIZE; >>> + size += PAGE_SIZE; >> This code in drm_prime_t_contiguous_size and here. I seem to remember >seeing >> the same pattern in other drivers. >> >> Would it worthwhile to make this a helper as well? >I think I've identified such patterns in all DRM drivers and replaced >with a common helper. So far I have no idea where to put such helper to >make it available for media/videobuf2, so those a few lines are indeed >duplicated here. I was thinking of drivers outside of DRM/media. Specifically RDMA. However, looking at that code, I see that my memory was a little off. It is working with continuous pages, but not finding the size. >> Also, isn't the sg_dma_len() the actual length of the chunk we are looking >at? >> >> If its I not PAGE_SIZE (ie. dma chunk is 4 * PAGE_SIZE?), does your >loop/calculation still work? > >scaterlist page iterators (for_each_sg_page/for_each_sg_dma_page and >their sgtable variants) always operates on PAGE_SIZE units. They >correctly handle larger sg_dma_len(). Ahh, ok, I see. Thank you! Mike > >Best regards >-- >Marek Szyprowski, PhD >Samsung R&D Institute Poland
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index d3a3ee5..bf31a9d 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -48,16 +48,15 @@ struct vb2_dc_buf { static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) { - struct scatterlist *s; dma_addr_t expected = sg_dma_address(sgt->sgl); - unsigned int i; + struct sg_dma_page_iter dma_iter; unsigned long size = 0; - for_each_sg(sgt->sgl, s, sgt->nents, i) { - if (sg_dma_address(s) != expected) + for_each_sgtable_dma_page(sgt, &dma_iter, 0) { + if (sg_page_iter_dma_address(&dma_iter) != expected) break; - expected = sg_dma_address(s) + sg_dma_len(s); - size += sg_dma_len(s); + expected += PAGE_SIZE; + size += PAGE_SIZE; } return size; } @@ -99,8 +98,7 @@ static void vb2_dc_prepare(void *buf_priv) if (!sgt || buf->db_attach) return; - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir); + dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); } static void vb2_dc_finish(void *buf_priv) @@ -112,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv) if (!sgt || buf->db_attach) return; - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); + dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); } /*********************************************/ @@ -273,8 +271,8 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf, * memory locations do not require any explicit cache * maintenance prior or after being used by the device. */ - dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); kfree(attach); db_attach->priv = NULL; @@ -299,8 +297,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( /* release any previous cache */ if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); attach->dma_dir = DMA_NONE; } @@ -308,9 +306,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map( * mapping to the client with new direction, no cache sync * required see comment in vb2_dc_dmabuf_ops_detach() */ - sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (!sgt->nents) { + if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); return ERR_PTR(-EIO); @@ -423,8 +420,8 @@ static void vb2_dc_put_userptr(void *buf_priv) * No need to sync to CPU, it's already synced to the CPU * since the finish() memop will have been called before this. */ - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); pages = frame_vector_pages(buf->vec); /* sgt should exist only if vector contains pages... */ BUG_ON(IS_ERR(pages)); @@ -521,9 +518,8 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, * No need to sync to the device, this will happen later when the * prepare() memop is called. */ - sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (sgt->nents <= 0) { + if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) { pr_err("failed to map scatterlist\n"); ret = -EIO; goto fail_sgt_init; @@ -545,8 +541,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, return buf; fail_map_sg: - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); fail_sgt_init: sg_free_table(sgt); diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index 92072a0..6ddf953 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs, * No need to sync to the device, this will happen later when the * prepare() memop is called. */ - sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (!sgt->nents) + if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) { goto fail_map; buf->handler.refcount = &buf->refcount; @@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv) if (refcount_dec_and_test(&buf->refcount)) { dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, buf->num_pages); - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); sg_free_table(buf->dma_sgt); @@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv) if (buf->db_attach) return; - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir); + dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir); } static void vb2_dma_sg_finish(void *buf_priv) @@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv) if (buf->db_attach) return; - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); + dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); } static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr, @@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr, * No need to sync to the device, this will happen later when the * prepare() memop is called. */ - sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (!sgt->nents) + if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) { goto userptr_fail_map; return buf; @@ -286,8 +283,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) dprintk(1, "%s: Releasing userspace buffer of %d pages\n", __func__, buf->num_pages); - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir, - DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); sg_free_table(buf->dma_sgt); @@ -410,8 +406,7 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf, /* release the scatterlist cache */ if (attach->dma_dir != DMA_NONE) - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir); sg_free_table(sgt); kfree(attach); db_attach->priv = NULL; @@ -436,15 +431,12 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map( /* release any previous cache */ if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir); attach->dma_dir = DMA_NONE; } /* mapping to the client with new direction */ - sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir); - if (!sgt->nents) { + if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); return ERR_PTR(-EIO); diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c index c66fda4..bf5ac63 100644 --- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c +++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c @@ -229,7 +229,7 @@ static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, kfree(attach); return ret; } - for_each_sg(sgt->sgl, sg, sgt->nents, i) { + for_each_sgtable_sg(sgt, sg, i) { struct page *page = vmalloc_to_page(vaddr); if (!page) { @@ -259,8 +259,7 @@ static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf, /* release the scatterlist cache */ if (attach->dma_dir != DMA_NONE) - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0); sg_free_table(sgt); kfree(attach); db_attach->priv = NULL; @@ -285,15 +284,12 @@ static struct sg_table *vb2_vmalloc_dmabuf_ops_map( /* release any previous cache */ if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0); attach->dma_dir = DMA_NONE; } /* mapping to the client with new direction */ - sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir); - if (!sgt->nents) { + if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); return ERR_PTR(-EIO);
Use recently introduced common wrappers operating directly on the struct sg_table objects and scatterlist page iterators to make the code a bit more compact, robust, easier to follow and copy/paste safe. No functional change, because the code already properly did all the scaterlist related calls. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski@samsung.com/T/ --- .../media/common/videobuf2/videobuf2-dma-contig.c | 41 ++++++++++------------ drivers/media/common/videobuf2/videobuf2-dma-sg.c | 32 +++++++---------- drivers/media/common/videobuf2/videobuf2-vmalloc.c | 12 +++---- 3 files changed, 34 insertions(+), 51 deletions(-)