| Message ID | 20200618153956.29558-5-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| State | Superseded |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! Perhaps something to improve:
[auto build test WARNING on next-20200618]
[also build test WARNING 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/20200619-000417
base: ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: alpha-allyesconfig (attached as .config)
compiler: alpha-linux-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=alpha
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
In file included from include/linux/dma-mapping.h:11,
from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:25:
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c: In function 'amdgpu_vram_mgr_alloc_sgt':
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~~~~~
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
480 | for_each_sgtable_sg(*sgt, sg, i)
| ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
480 | for_each_sgtable_sg(*sgt, sg, i)
| ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
484 | for_each_sgtable_sg(*sgt, sg, i) {
| ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
484 | for_each_sgtable_sg(*sgt, sg, i) {
| ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
504 | for_each_sgtable_sg(*sgt, sg, i) {
| ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 | for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
| ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
| ^~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
504 | for_each_sgtable_sg(*sgt, sg, i) {
| ^~~~~~~~~~~~~~~~~~~
In file included from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
At top level:
drivers/gpu/drm/amd/amdgpu/amdgpu.h:190:18: warning: 'sched_policy' defined but not used [-Wunused-const-variable=]
190 | static const int sched_policy = KFD_SCHED_POLICY_HWS;
| ^~~~~~~~~~~~
In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc_types.h:33,
from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:30,
from drivers/gpu/drm/amd/amdgpu/../include/dm_pp_interface.h:26,
from drivers/gpu/drm/amd/amdgpu/amdgpu.h:65,
from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:76:32: warning: 'dc_fixpt_ln2_div_2' defined but not used [-Wunused-const-variable=]
76 | static const struct fixed31_32 dc_fixpt_ln2_div_2 = { 1488522236LL };
| ^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:75:32: warning: 'dc_fixpt_ln2' defined but not used [-Wunused-const-variable=]
75 | static const struct fixed31_32 dc_fixpt_ln2 = { 2977044471LL };
| ^~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:74:32: warning: 'dc_fixpt_e' defined but not used [-Wunused-const-variable=]
74 | static const struct fixed31_32 dc_fixpt_e = { 11674931555LL };
| ^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:73:32: warning: 'dc_fixpt_two_pi' defined but not used [-Wunused-const-variable=]
73 | static const struct fixed31_32 dc_fixpt_two_pi = { 26986075409LL };
| ^~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:72:32: warning: 'dc_fixpt_pi' defined but not used [-Wunused-const-variable=]
72 | static const struct fixed31_32 dc_fixpt_pi = { 13493037705LL };
| ^~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:67:32: warning: 'dc_fixpt_zero' defined but not used [-Wunused-const-variable=]
67 | static const struct fixed31_32 dc_fixpt_zero = { 0 };
| ^~~~~~~~~~~~~
vim +/for_each_sgtable_sg +480 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
444
445 /**
446 * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
447 *
448 * @adev: amdgpu device pointer
449 * @mem: TTM memory object
450 * @dev: the other device
451 * @dir: dma direction
452 * @sgt: resulting sg table
453 *
454 * Allocate and fill a sg table from a VRAM allocation.
455 */
456 int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
457 struct ttm_mem_reg *mem,
458 struct device *dev,
459 enum dma_data_direction dir,
460 struct sg_table **sgt)
461 {
462 struct drm_mm_node *node;
463 struct scatterlist *sg;
464 int num_entries = 0;
465 unsigned int pages;
466 int i, r;
467
468 *sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
469 if (!*sgt)
470 return -ENOMEM;
471
472 for (pages = mem->num_pages, node = mem->mm_node;
473 pages; pages -= node->size, ++node)
474 ++num_entries;
475
476 r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
477 if (r)
478 goto error_free;
479
> 480 for_each_sgtable_sg(*sgt, sg, i)
481 sg->length = 0;
482
483 node = mem->mm_node;
484 for_each_sgtable_sg(*sgt, sg, i) {
485 phys_addr_t phys = (node->start << PAGE_SHIFT) +
486 adev->gmc.aper_base;
487 size_t size = node->size << PAGE_SHIFT;
488 dma_addr_t addr;
489
490 ++node;
491 addr = dma_map_resource(dev, phys, size, dir,
492 DMA_ATTR_SKIP_CPU_SYNC);
493 r = dma_mapping_error(dev, addr);
494 if (r)
495 goto error_unmap;
496
497 sg_set_page(sg, NULL, size, 0);
498 sg_dma_address(sg) = addr;
499 sg_dma_len(sg) = size;
500 }
501 return 0;
502
503 error_unmap:
504 for_each_sgtable_sg(*sgt, sg, i) {
505 if (!sg->length)
506 continue;
507
508 dma_unmap_resource(dev, sg->dma_address,
509 sg->length, dir,
510 DMA_ATTR_SKIP_CPU_SYNC);
511 }
512 sg_free_table(*sgt);
513
514 error_free:
515 kfree(*sgt);
516 return r;
517 }
518
---
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/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c index 43d8ed7dbd00..519ce4427fce 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c @@ -307,8 +307,8 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach, if (IS_ERR(sgt)) return sgt; - if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir, - DMA_ATTR_SKIP_CPU_SYNC)) + if (dma_map_sgtable(attach->dev, sgt, dir, + DMA_ATTR_SKIP_CPU_SYNC)) goto error_free; break; @@ -349,7 +349,7 @@ static void amdgpu_dma_buf_unmap(struct dma_buf_attachment *attach, struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); if (sgt->sgl->page_link) { - dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir); + dma_unmap_sgtable(attach->dev, sgt, dir, 0); sg_free_table(sgt); kfree(sgt); } else { diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 5129a996e941..97fb73e5a6ae 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1025,7 +1025,6 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm) { struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev); struct amdgpu_ttm_tt *gtt = (void *)ttm; - unsigned nents; int r; int write = !(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY); @@ -1040,9 +1039,8 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm) goto release_sg; /* Map SG to device */ - r = -ENOMEM; - nents = dma_map_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction); - if (nents == 0) + r = dma_map_sgtable(adev->dev, ttm->sg, direction, 0); + if (r) goto release_sg; /* convert SG to linear array of pages and dma addresses */ @@ -1073,8 +1071,7 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm) return; /* unmap the pages mapped to the device */ - dma_unmap_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction); - + dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0); sg_free_table(ttm->sg); #if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c index d399e5893170..75495a7898b9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -477,11 +477,11 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev, if (r) goto error_free; - for_each_sg((*sgt)->sgl, sg, num_entries, i) + for_each_sgtable_sg(*sgt, sg, i) sg->length = 0; node = mem->mm_node; - for_each_sg((*sgt)->sgl, sg, num_entries, i) { + for_each_sgtable_sg(*sgt, sg, i) { phys_addr_t phys = (node->start << PAGE_SHIFT) + adev->gmc.aper_base; size_t size = node->size << PAGE_SHIFT; @@ -501,7 +501,7 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev, return 0; error_unmap: - for_each_sg((*sgt)->sgl, sg, num_entries, i) { + for_each_sgtable_sg(*sgt, sg, i) { if (!sg->length) continue; @@ -532,7 +532,7 @@ void amdgpu_vram_mgr_free_sgt(struct amdgpu_device *adev, struct scatterlist *sg; int i; - for_each_sg(sgt->sgl, sg, sgt->nents, i) + for_each_sgtable_sg(sgt, sg, i) dma_unmap_resource(dev, sg->dma_address, sg->length, dir, DMA_ATTR_SKIP_CPU_SYNC);
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: Christian König <christian.koenig@amd.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 6 +++--- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 9 +++------ drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 8 ++++---- 3 files changed, 10 insertions(+), 13 deletions(-)