| Message ID | 20200619103636.11974-32-m.szyprowski@samsung.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | DRM: fix struct sg_table nents vs. orig_nents misuse | expand |
Hi Marek,
I love your patch! Yet something to improve:
[auto build test ERROR on next-20200618]
[also build test ERROR on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-184302
base: ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: c6x-allyesconfig (attached as .config)
compiler: c6x-elf-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=c6x
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
drivers/staging/media/tegra-vde/iommu.c: In function 'tegra_vde_iommu_map':
>> drivers/staging/media/tegra-vde/iommu.c:39:9: error: implicit declaration of function 'iommu_map_sgtable'; did you mean 'dma_map_sgtable'? [-Werror=implicit-function-declaration]
39 | size = iommu_map_sgtable(vde->domain, addr, sgt,
| ^~~~~~~~~~~~~~~~~
| dma_map_sgtable
cc1: some warnings being treated as errors
vim +39 drivers/staging/media/tegra-vde/iommu.c
18
19 int tegra_vde_iommu_map(struct tegra_vde *vde,
20 struct sg_table *sgt,
21 struct iova **iovap,
22 size_t size)
23 {
24 struct iova *iova;
25 unsigned long shift;
26 unsigned long end;
27 dma_addr_t addr;
28
29 end = vde->domain->geometry.aperture_end;
30 size = iova_align(&vde->iova, size);
31 shift = iova_shift(&vde->iova);
32
33 iova = alloc_iova(&vde->iova, size >> shift, end >> shift, true);
34 if (!iova)
35 return -ENOMEM;
36
37 addr = iova_dma_addr(&vde->iova, iova);
38
> 39 size = iommu_map_sgtable(vde->domain, addr, sgt,
40 IOMMU_READ | IOMMU_WRITE);
41 if (!size) {
42 __free_iova(&vde->iova, iova);
43 return -ENXIO;
44 }
45
46 *iovap = iova;
47
48 return 0;
49 }
50
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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diff --git a/drivers/staging/media/tegra-vde/iommu.c b/drivers/staging/media/tegra-vde/iommu.c index 6af863d92123..adf8dc7ee25c 100644 --- a/drivers/staging/media/tegra-vde/iommu.c +++ b/drivers/staging/media/tegra-vde/iommu.c @@ -36,8 +36,8 @@ int tegra_vde_iommu_map(struct tegra_vde *vde, addr = iova_dma_addr(&vde->iova, iova); - size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents, - IOMMU_READ | IOMMU_WRITE); + size = iommu_map_sgtable(vde->domain, addr, sgt, + IOMMU_READ | IOMMU_WRITE); if (!size) { __free_iova(&vde->iova, iova); return -ENXIO;
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: Dmitry Osipenko <digetx@gmail.com> --- drivers/staging/media/tegra-vde/iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.17.1 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel