I'd like to make sure this has no side effects on x86 guests, it probably is safe, but keep an eye for regression reports. Reviewed-by: Dave Airlie <airlied@xxxxxxxxxx> Dave. On Wed, Mar 30, 2022 at 8:20 PM Cong Liu <liucong2@xxxxxxxxxx> wrote: > > any suggestions or extra test I can do now? > > Regards, > Cong > > On 2022/3/25 15:45, Christian König wrote: > > Am 24.03.22 um 11:49 schrieb Cong Liu: > >> qxl use ioremap to map ram_header and rom, in the arm64 implementation, > >> the device is mapped as DEVICE_nGnRE, it can not support unaligned > >> access. and qxl is a virtual device, it can be treated more like RAM > >> than actual MMIO registers. use ioremap_wc() replace it. > >> > >> Signed-off-by: Cong Liu <liucong2@xxxxxxxxxx> > > > > Looks sane to me, but I'm really not involved enough to fully judge. > > > > Acked-by: Christian König <christian.koenig@xxxxxxx> > > > >> --- > >> drivers/gpu/drm/qxl/qxl_kms.c | 4 ++-- > >> drivers/gpu/drm/qxl/qxl_ttm.c | 4 ++-- > >> 2 files changed, 4 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/qxl/qxl_kms.c > >> b/drivers/gpu/drm/qxl/qxl_kms.c > >> index 4dc5ad13f12c..a054e4a00fe8 100644 > >> --- a/drivers/gpu/drm/qxl/qxl_kms.c > >> +++ b/drivers/gpu/drm/qxl/qxl_kms.c > >> @@ -165,7 +165,7 @@ int qxl_device_init(struct qxl_device *qdev, > >> (int)qdev->surfaceram_size / 1024, > >> (sb == 4) ? "64bit" : "32bit"); > >> - qdev->rom = ioremap(qdev->rom_base, qdev->rom_size); > >> + qdev->rom = ioremap_wc(qdev->rom_base, qdev->rom_size); > >> if (!qdev->rom) { > >> pr_err("Unable to ioremap ROM\n"); > >> r = -ENOMEM; > >> @@ -183,7 +183,7 @@ int qxl_device_init(struct qxl_device *qdev, > >> goto rom_unmap; > >> } > >> - qdev->ram_header = ioremap(qdev->vram_base + > >> + qdev->ram_header = ioremap_wc(qdev->vram_base + > >> qdev->rom->ram_header_offset, > >> sizeof(*qdev->ram_header)); > >> if (!qdev->ram_header) { > >> diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c > >> b/drivers/gpu/drm/qxl/qxl_ttm.c > >> index b2e33d5ba5d0..95df5750f47f 100644 > >> --- a/drivers/gpu/drm/qxl/qxl_ttm.c > >> +++ b/drivers/gpu/drm/qxl/qxl_ttm.c > >> @@ -82,13 +82,13 @@ int qxl_ttm_io_mem_reserve(struct ttm_device *bdev, > >> case TTM_PL_VRAM: > >> mem->bus.is_iomem = true; > >> mem->bus.offset = (mem->start << PAGE_SHIFT) + qdev->vram_base; > >> - mem->bus.caching = ttm_cached; > >> + mem->bus.caching = ttm_write_combined; > >> break; > >> case TTM_PL_PRIV: > >> mem->bus.is_iomem = true; > >> mem->bus.offset = (mem->start << PAGE_SHIFT) + > >> qdev->surfaceram_base; > >> - mem->bus.caching = ttm_cached; > >> + mem->bus.caching = ttm_write_combined; > >> break; > >> default: > >> return -EINVAL; > > >