| Message ID | 1461758429-12913-1-git-send-email-m.szyprowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
Hello, On 2016-04-27 14:10, Hans Verkuil wrote: > On 04/27/2016 02:00 PM, Marek Szyprowski wrote: >> Add a helper function for device drivers to set DMA's max_seg_size. >> Setting it to largest possible value lets DMA-mapping API always create >> contiguous mappings in DMA address space. This is essential for all >> devices, which use dma-contig videobuf2 memory allocator and shared >> buffers. >> >> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> >> --- >> This patch was posted earlier as a part of >> http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/97316 >> thread, but applying it is really needed to get all Exynos multimedia >> drivers working with IOMMU enabled. >> >> Best regards, >> Marek Szyprowski >> --- >> drivers/media/v4l2-core/videobuf2-dma-contig.c | 15 +++++++++++++++ >> include/media/videobuf2-dma-contig.h | 1 + >> 2 files changed, 16 insertions(+) >> >> diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c >> index 5361197..f611456 100644 >> --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c >> +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c >> @@ -753,6 +753,21 @@ void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) >> } >> EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); >> >> +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) >> +{ >> + if (!dev->dma_parms) { >> + dev->dma_parms = devm_kzalloc(dev, sizeof(dev->dma_parms), >> + GFP_KERNEL); > The v3 patch from December uses kzalloc here. Is this perhaps on old version? Right, my fault. I will do another resend (and fix the typo in the second patch). >> + if (!dev->dma_parms) >> + return -ENOMEM; >> + } >> + if (dma_get_max_seg_size(dev) < size) >> + return dma_set_max_seg_size(dev, size); >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); > Admittedly I haven't looked closely at this, but is this something that you > want for all dma-contig devices? Or to rephrase this question: what type of > devices will need this? This is needed for all devices using vb2-dc, iommu and user-ptr mode, however in the previous discussions (see https://patchwork.linuxtv.org/patch/30870/ ) it has been suggested to make it via common helper instead of forcing it in vb2-dc. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index 5361197..f611456 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -753,6 +753,21 @@ void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) } EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) +{ + if (!dev->dma_parms) { + dev->dma_parms = devm_kzalloc(dev, sizeof(dev->dma_parms), + GFP_KERNEL); + if (!dev->dma_parms) + return -ENOMEM; + } + if (dma_get_max_seg_size(dev) < size) + return dma_set_max_seg_size(dev, size); + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); + MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h index 2087c9a..98857b5 100644 --- a/include/media/videobuf2-dma-contig.h +++ b/include/media/videobuf2-dma-contig.h @@ -35,6 +35,7 @@ static inline void *vb2_dma_contig_init_ctx(struct device *dev) } void vb2_dma_contig_cleanup_ctx(void *alloc_ctx); +int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size); extern const struct vb2_mem_ops vb2_dma_contig_memops;
Add a helper function for device drivers to set DMA's max_seg_size. Setting it to largest possible value lets DMA-mapping API always create contiguous mappings in DMA address space. This is essential for all devices, which use dma-contig videobuf2 memory allocator and shared buffers. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- This patch was posted earlier as a part of http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/97316 thread, but applying it is really needed to get all Exynos multimedia drivers working with IOMMU enabled. Best regards, Marek Szyprowski --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 15 +++++++++++++++ include/media/videobuf2-dma-contig.h | 1 + 2 files changed, 16 insertions(+) -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html