LoongArch maintains cache coherency in hardware, but its WUC attribute (Weak-ordered UnCached, which is similar to WC) is out of the scope of cache coherency machanism. This means WUC can only used for write-only memory regions. So use uncached ioremap() for LoongArch in the amdgpu driver. Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index c5ef7f7bdc15..c6888a58819a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1750,8 +1750,13 @@ int amdgpu_ttm_init(struct amdgpu_device *adev) else #endif +#ifdef CONFIG_LOONGARCH + adev->mman.aper_base_kaddr = ioremap(adev->gmc.aper_base, + adev->gmc.visible_vram_size); +#else adev->mman.aper_base_kaddr = ioremap_wc(adev->gmc.aper_base, adev->gmc.visible_vram_size); +#endif #endif /* -- 2.39.1
