[PATCH v2 2/2] amdgpu: Wrap dev_err() calls on vm faults with printk_ratelimit()

[Edward O'Callaghan]

It can be the case that upon GPU page faults we start trashing
the logs, and so let us ratelimit here to avoid that.

V2. Fix issue where calling dev_err_ratelimited separately for
    each line means that some lines corresponding to a single
    VM fault may or may not appear depending on the rate.
    - Michel Dänzer.

Signed-off-by: Edward O'Callaghan <funfunctor at folklore1984.net>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 16 +++++++++-------
 drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 16 +++++++++-------
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 16 +++++++++-------
 3 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
index b13c8aa..1721c4a 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
@@ -1007,13 +1007,15 @@ static int gmc_v6_0_process_interrupt(struct amdgpu_device *adev,
 	if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_FIRST)
 		gmc_v6_0_set_fault_enable_default(adev, false);
 
-	dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
-		entry->src_id, entry->src_data);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
-		addr);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
-		status);
-	gmc_v6_0_vm_decode_fault(adev, status, addr, 0);
+	if (printk_ratelimit()) {
+		dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
+			entry->src_id, entry->src_data);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
+			addr);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
+			status);
+		gmc_v6_0_vm_decode_fault(adev, status, addr, 0);
+	}
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index a0df431..940857e 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -1198,13 +1198,15 @@ static int gmc_v7_0_process_interrupt(struct amdgpu_device *adev,
 	if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_FIRST)
 		gmc_v7_0_set_fault_enable_default(adev, false);
 
-	dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
-		entry->src_id, entry->src_data);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
-		addr);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
-		status);
-	gmc_v7_0_vm_decode_fault(adev, status, addr, mc_client);
+	if (printk_ratelimit()) {
+		dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
+			entry->src_id, entry->src_data);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
+			addr);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
+			status);
+		gmc_v7_0_vm_decode_fault(adev, status, addr, mc_client);
+	}
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 7285294..77690f8 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -1242,13 +1242,15 @@ static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
 	if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_FIRST)
 		gmc_v8_0_set_fault_enable_default(adev, false);
 
-	dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
-		entry->src_id, entry->src_data);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
-		addr);
-	dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
-		status);
-	gmc_v8_0_vm_decode_fault(adev, status, addr, mc_client);
+	if (printk_ratelimit()) {
+		dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
+			entry->src_id, entry->src_data);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
+			addr);
+		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
+			status);
+		gmc_v8_0_vm_decode_fault(adev, status, addr, mc_client);
+	}
 
 	return 0;
 }
-- 
2.7.4