[PATCH] drm/amdgpu: Rearrange WREG32 operations in gfxhub_v2_1.c

From: ghostfly233
Date: Sat May 20 2023 - 14:05:23 EST


In gfxhub_v2_1_setup_vmid_config(), the GCVM_CONTEXT1_CNTL reg is
written before related GCVM_CONTEXT1_PAGE_TABLE_START_ADDR and
GCVM_CONTEXT1_PAGE_TABLE_END_ADDR regs are written, which may
cause undefined behavior.

This patch rearranges WREG32 operations in gfxhub_v2_1_setup_vmid_config(),
so that it can ensure the addresses are initialized before CNTL is enabled
and reduce the risk of encountering undefined behavior.

Signed-off-by: Zibin Liu <ghostfly23333@xxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
index 4aacbbec31e2..6d094e7315eb 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_1.c
@@ -321,8 +321,6 @@ static void gfxhub_v2_1_setup_vmid_config(struct amdgpu_device *adev)
tmp = REG_SET_FIELD(tmp, GCVM_CONTEXT1_CNTL,
RETRY_PERMISSION_OR_INVALID_PAGE_FAULT,
!adev->gmc.noretry);
- WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL,
- i * hub->ctx_distance, tmp);
WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_PAGE_TABLE_START_ADDR_LO32,
i * hub->ctx_addr_distance, 0);
WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_PAGE_TABLE_START_ADDR_HI32,
@@ -333,6 +331,8 @@ static void gfxhub_v2_1_setup_vmid_config(struct amdgpu_device *adev)
WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_PAGE_TABLE_END_ADDR_HI32,
i * hub->ctx_addr_distance,
upper_32_bits(adev->vm_manager.max_pfn - 1));
+ WREG32_SOC15_OFFSET(GC, 0, mmGCVM_CONTEXT1_CNTL,
+ i * hub->ctx_distance, tmp);
}

hub->vm_cntx_cntl = tmp;
--
2.34.1