When gfxoff is enabled, accessing gfx registers via MMIO
can lead to a hang.

v2: return cached registers properly.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=205497
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/nv.c    | 27 ++++++++++++++++----------
 drivers/gpu/drm/amd/amdgpu/soc15.c | 31 ++++++++++++++++++------------
 2 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
index af68f9815f28..7283d6198b89 100644
--- a/drivers/gpu/drm/amd/amdgpu/nv.c
+++ b/drivers/gpu/drm/amd/amdgpu/nv.c
@@ -201,17 +201,25 @@ static uint32_t nv_read_indexed_register(struct 
amdgpu_device *adev, u32 se_num,
        return val;
 }
 
-static uint32_t nv_get_register_value(struct amdgpu_device *adev,
+static int nv_get_register_value(struct amdgpu_device *adev,
                                      bool indexed, u32 se_num,
-                                     u32 sh_num, u32 reg_offset)
+                                     u32 sh_num, u32 reg_offset,
+                                     u32 *value)
 {
        if (indexed) {
-               return nv_read_indexed_register(adev, se_num, sh_num, 
reg_offset);
+               if (adev->pm.pp_feature & PP_GFXOFF_MASK)
+                       return -EINVAL;
+               *value = nv_read_indexed_register(adev, se_num, sh_num, 
reg_offset);
        } else {
-               if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmGB_ADDR_CONFIG))
-                       return adev->gfx.config.gb_addr_config;
-               return RREG32(reg_offset);
+               if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmGB_ADDR_CONFIG)) {
+                       *value = adev->gfx.config.gb_addr_config;
+               } else {
+                       if (adev->pm.pp_feature & PP_GFXOFF_MASK)
+                               return -EINVAL;
+                       *value = RREG32(reg_offset);
+               }
        }
+       return 0;
 }
 
 static int nv_read_register(struct amdgpu_device *adev, u32 se_num,
@@ -227,10 +235,9 @@ static int nv_read_register(struct amdgpu_device *adev, 
u32 se_num,
                    (adev->reg_offset[en->hwip][en->inst][en->seg] + 
en->reg_offset))
                        continue;
 
-               *value = nv_get_register_value(adev,
-                                              
nv_allowed_read_registers[i].grbm_indexed,
-                                              se_num, sh_num, reg_offset);
-               return 0;
+               return nv_get_register_value(adev,
+                                            
nv_allowed_read_registers[i].grbm_indexed,
+                                            se_num, sh_num, reg_offset, value);
        }
        return -EINVAL;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c 
b/drivers/gpu/drm/amd/amdgpu/soc15.c
index 305ad3eec987..2cc16e9f39fb 100644
--- a/drivers/gpu/drm/amd/amdgpu/soc15.c
+++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
@@ -363,19 +363,27 @@ static uint32_t soc15_read_indexed_register(struct 
amdgpu_device *adev, u32 se_n
        return val;
 }
 
-static uint32_t soc15_get_register_value(struct amdgpu_device *adev,
+static int soc15_get_register_value(struct amdgpu_device *adev,
                                         bool indexed, u32 se_num,
-                                        u32 sh_num, u32 reg_offset)
+                                        u32 sh_num, u32 reg_offset,
+                                        u32 *value)
 {
        if (indexed) {
-               return soc15_read_indexed_register(adev, se_num, sh_num, 
reg_offset);
+               if (adev->pm.pp_feature & PP_GFXOFF_MASK)
+                       return -EINVAL;
+               *value = soc15_read_indexed_register(adev, se_num, sh_num, 
reg_offset);
        } else {
-               if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmGB_ADDR_CONFIG))
-                       return adev->gfx.config.gb_addr_config;
-               else if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmDB_DEBUG2))
-                       return adev->gfx.config.db_debug2;
-               return RREG32(reg_offset);
+               if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmGB_ADDR_CONFIG)) {
+                       *value = adev->gfx.config.gb_addr_config;
+               } else if (reg_offset == SOC15_REG_OFFSET(GC, 0, mmDB_DEBUG2)) {
+                       *value = adev->gfx.config.db_debug2;
+               } else {
+                       if (adev->pm.pp_feature & PP_GFXOFF_MASK)
+                               return -EINVAL;
+                       *value = RREG32(reg_offset);
+               }
        }
+       return 0;
 }
 
 static int soc15_read_register(struct amdgpu_device *adev, u32 se_num,
@@ -391,10 +399,9 @@ static int soc15_read_register(struct amdgpu_device *adev, 
u32 se_num,
                                        + en->reg_offset))
                        continue;
 
-               *value = soc15_get_register_value(adev,
-                                                 
soc15_allowed_read_registers[i].grbm_indexed,
-                                                 se_num, sh_num, reg_offset);
-               return 0;
+               return soc15_get_register_value(adev,
+                                               
soc15_allowed_read_registers[i].grbm_indexed,
+                                               se_num, sh_num, reg_offset, 
value);
        }
        return -EINVAL;
 }
-- 
2.23.0

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

Reply via email to