RE: [PATCH] drm/ttm: ioremap buffer according to TTM mem caching setting

"Zeng, Oak" <Oak.Zeng@xxxxxxx> · Tue, 2 Mar 2021 22:45:15 +0000

[AMD Official Use Only - Internal Distribution Only]

Hi Daniel, Thomas, Dan,

Does below message mean the calling ioremap_cache failed intel’s driver build? I can see both ioremap_cache and ioremap_wc are defined in arch/x86/mm/ioremap.c – why ioremap_wc doesn’t break intel driver’s build?

Are we supposed to use memremap (offset, size, MEMREMAP_WB) to replace ioremap_cache? When I read here
https://lwn.net/Articles/653585/ I felt that ioremap_cache returns an address annotated with _iomem while memremap returns an address without __iomem annotation. In our use case, GPU memory is treated as UEFI SPM
 (specific purpose memory). I am not very sure whether memremap (thus no __iomem annotation) is the right thing to do. What I am sure is, we have tested ioremap_cache and it works fine on AMD system.

I will send out a test patch replacing ioremap_cache with ioremap_wc, to trigger Intel build robot to see whether it fails Intel build. I suppose it will not fail Intel build.

Regards,
Oak

From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx>

Sent: Tuesday, March 2, 2021 6:31 AM

To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; Daniel Vetter <daniel@xxxxxxxx>; Dave Airlie <airlied@xxxxxxxxxx>; Thomas Hellström (Intel) <thomas_os@xxxxxxxxxxxx>

Cc: Zeng, Oak <Oak.Zeng@xxxxxxx>; kbuild-all@xxxxxxxxxxxx; Kuehling, Felix <Felix.Kuehling@xxxxxxx>; Kasiviswanathan, Harish <Harish.Kasiviswanathan@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Huang, JinHuiEric <JinHuiEric.Huang@xxxxxxx>;
 Koenig, Christian <Christian.Koenig@xxxxxxx>

Subject: Re: [PATCH] drm/ttm: ioremap buffer according to TTM mem caching setting

Hi guys,

adding the usual suspects direct. Does anybody of hand know how to check if an architecture supports ioremap_cache()?

For now we only need this on X86, but I would feel better if we don't use an #ifdef here.

Regards,

Christian.

Am 02.03.21 um 05:12 schrieb kernel test robot:

Hi Oak,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-tip/drm-tip linus/master v5.12-rc1 next-20210302]
[cannot apply to tegra-drm/drm/tegra/for-next drm-exynos/exynos-drm-next drm/drm-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Oak-Zeng/drm-ttm-ioremap-buffer-according-to-TTM-mem-caching-setting/20210302-064500
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: parisc-randconfig-r012-20210302 (attached as .config)
compiler: hppa-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
        # https://github.com/0day-ci/linux/commit/225bb3711439ec559dd72ae5af8e62d34ea60a64
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Oak-Zeng/drm-ttm-ioremap-buffer-according-to-TTM-mem-caching-setting/20210302-064500
        git checkout 225bb3711439ec559dd72ae5af8e62d34ea60a64
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

   drivers/gpu/drm/ttm/ttm_bo_util.c: In function 'ttm_resource_ioremap':

drivers/gpu/drm/ttm/ttm_bo_util.c:95:11: error: implicit declaration of function 'ioremap_cache'; did you mean 'ioremap_uc'? [-Werror=implicit-function-declaration]

      95 |    addr = ioremap_cache(mem->bus.offset, bus_size);
         |           ^~~~~~~~~~~~~
         |           ioremap_uc
   drivers/gpu/drm/ttm/ttm_bo_util.c:95:9: warning: assignment to 'void *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
      95 |    addr = ioremap_cache(mem->bus.offset, bus_size);
         |         ^
   drivers/gpu/drm/ttm/ttm_bo_util.c: In function 'ttm_bo_ioremap':
   drivers/gpu/drm/ttm/ttm_bo_util.c:379:17: warning: assignment to 'void *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     379 |    map->virtual = ioremap_cache(bo->mem.bus.offset + offset,
         |                 ^
   drivers/gpu/drm/ttm/ttm_bo_util.c: In function 'ttm_bo_vmap':
   drivers/gpu/drm/ttm/ttm_bo_util.c:500:16: warning: assignment to 'void *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     500 |    vaddr_iomem = ioremap_cache(mem->bus.offset,
         |                ^
   cc1: some warnings being treated as errors

vim +95 drivers/gpu/drm/ttm/ttm_bo_util.c

    74  
    75  static int ttm_resource_ioremap(struct ttm_bo_device *bdev,
    76                                struct ttm_resource *mem,
    77                                void **virtual)
    78  {
    79          int ret;
    80          void *addr;
    81  
    82          *virtual = NULL;
    83          ret = ttm_mem_io_reserve(bdev, mem);
    84          if (ret || !mem->bus.is_iomem)
    85                  return ret;
    86  
    87          if (mem->bus.addr) {
    88                  addr = mem->bus.addr;
    89          } else {
    90                  size_t bus_size = (size_t)mem->num_pages << PAGE_SHIFT;
    91  
    92                  if (mem->bus.caching == ttm_write_combined)
    93                         addr = ioremap_wc(mem->bus.offset, bus_size);
    94                  else if (mem->bus.caching == ttm_cached)
  > 95                         addr = ioremap_cache(mem->bus.offset, bus_size);
    96                  else
    97                         addr = ioremap(mem->bus.offset, bus_size);
    98                  if (!addr) {
    99                         ttm_mem_io_free(bdev, mem);
   100                         return -ENOMEM;
   101                  }
   102          }
   103          *virtual = addr;
   104          return 0;
   105  }
   106  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx