drm/amdgpu: Remove unnecessary TLB workaround (v2)

This workaround is better handled in user mode in a way that doesn't
require allocating extra memory and breaking userptr BOs.

The TLB bug is a performance bug, not a functional or security bug.
Hence it is safe to remove this kernel part of the workaround to
allow a better workaround using only virtual address alignments in
user mode.

v2: Removed VI_BO_SIZE_ALIGN definition

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index f8328e0..55fce91 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -33,11 +33,6 @@
 #include "amdgpu_amdkfd.h"
 #include "amdgpu_dma_buf.h"
 
-/* Special VM and GART address alignment needed for VI pre-Fiji due to
- * a HW bug.
- */
-#define VI_BO_SIZE_ALIGN (0x8000)
-
 /* BO flag to indicate a KFD userptr BO */
 #define AMDGPU_AMDKFD_USERPTR_BO (1ULL << 63)
 
@@ -1111,7 +1106,6 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
        uint64_t user_addr = 0;
        struct amdgpu_bo *bo;
        struct amdgpu_bo_param bp;
-       int byte_align;
        u32 domain, alloc_domain;
        u64 alloc_flags;
        int ret;
@@ -1166,15 +1160,6 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
        if ((*mem)->aql_queue)
                size = size >> 1;
 
-       /* Workaround for TLB bug on older VI chips */
-       byte_align = (adev->family == AMDGPU_FAMILY_VI &&
-                       adev->asic_type != CHIP_FIJI &&
-                       adev->asic_type != CHIP_POLARIS10 &&
-                       adev->asic_type != CHIP_POLARIS11 &&
-                       adev->asic_type != CHIP_POLARIS12 &&
-                       adev->asic_type != CHIP_VEGAM) ?
-                       VI_BO_SIZE_ALIGN : 1;
-
        (*mem)->alloc_flags = flags;
 
        amdgpu_sync_create(&(*mem)->sync);
@@ -1190,7 +1175,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 
        memset(&bp, 0, sizeof(bp));
        bp.size = size;
-       bp.byte_align = byte_align;
+       bp.byte_align = 1;
        bp.domain = alloc_domain;
        bp.flags = alloc_flags;
        bp.type = bo_type;