7 files changed, 112 insertions, 13 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 8fcc743..c91d5c7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2682,6 +2682,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	}
 
 	INIT_KFIFO(vm->faults);
+	vm->fault_credit = 16;
 
 	return 0;
 
@@ -2776,6 +2777,36 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 }
 
 /**
+ * amdgpu_vm_pasid_fault_credit - Check fault credit for given PASID
+ *
+ * @adev: amdgpu_device pointer
+ * @pasid: PASID do identify the VM
+ *
+ * This function is expected to be called in interrupt context. Returns
+ * true if there was fault credit, false otherwise
+ */
+bool amdgpu_vm_pasid_fault_credit(struct amdgpu_device *adev,
+				  unsigned int pasid)
+{
+	struct amdgpu_vm *vm;
+
+	spin_lock(&adev->vm_manager.pasid_lock);
+	vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
+	spin_unlock(&adev->vm_manager.pasid_lock);
+	if (!vm)
+		/* VM not found, can't track fault credit */
+		return true;
+
+	/* No lock needed. only accessed by IRQ handler */
+	if (!vm->fault_credit)
+		/* Too many faults in this VM */
+		return false;
+
+	vm->fault_credit--;
+	return true;
+}
+
+/**
  * amdgpu_vm_manager_init - init the VM manager
  *
  * @adev: amdgpu_device pointer
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 447ed6e..66efbc2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -165,8 +165,11 @@ struct amdgpu_vm {
 	/* Flag to indicate ATS support from PTE for GFX9 */
 	bool			pte_support_ats;
 
-	/* Up to 128 pending page faults */
+	/* Up to 128 pending retry page faults */
 	DECLARE_KFIFO(faults, u64, 128);
+
+	/* Limit non-retry fault storms */
+	unsigned int		fault_credit;
 };
 
 struct amdgpu_vm_id {
@@ -244,6 +247,8 @@ void amdgpu_vm_manager_fini(struct amdgpu_device *adev);
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 		   int vm_context, unsigned int pasid);
 void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm);
+bool amdgpu_vm_pasid_fault_credit(struct amdgpu_device *adev,
+				  unsigned int pasid);
 void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
 			 struct list_head *validated,
 			 struct amdgpu_bo_list_entry *entry);
diff --git a/drivers/gpu/drm/amd/amdgpu/cik_ih.c b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
index 07d3d89..a870b35 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
@@ -237,8 +237,23 @@ static u32 cik_ih_get_wptr(struct amdgpu_device *adev)
  */
 static bool cik_ih_prescreen_iv(struct amdgpu_device *adev)
 {
-	/* Process all interrupts */
-	return true;
+	u32 ring_index = adev->irq.ih.rptr >> 2;
+	u16 pasid;
+
+	switch (le32_to_cpu(adev->irq.ih.ring[ring_index]) & 0xff) {
+	case 146:
+	case 147:
+		pasid = le32_to_cpu(adev->irq.ih.ring[ring_index + 2]) >> 16;
+		if (!pasid || amdgpu_vm_pasid_fault_credit(adev, pasid))
+			return true;
+		break;
+	default:
+		/* Not a VM fault */
+		return true;
+	}
+
+	adev->irq.ih.rptr += 16;
+	return false;
 }
 
  /**
diff --git a/drivers/gpu/drm/amd/amdgpu/cz_ih.c b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
index b6cdf4a..fa61d64 100644
--- a/drivers/gpu/drm/amd/amdgpu/cz_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
@@ -216,8 +216,23 @@ static u32 cz_ih_get_wptr(struct amdgpu_device *adev)
  */
 static bool cz_ih_prescreen_iv(struct amdgpu_device *adev)
 {
-	/* Process all interrupts */
-	return true;
+	u32 ring_index = adev->irq.ih.rptr >> 2;
+	u16 pasid;
+
+	switch (le32_to_cpu(adev->irq.ih.ring[ring_index]) & 0xff) {
+	case 146:
+	case 147:
+		pasid = le32_to_cpu(adev->irq.ih.ring[ring_index + 2]) >> 16;
+		if (!pasid || amdgpu_vm_pasid_fault_credit(adev, pasid))
+			return true;
+		break;
+	default:
+		/* Not a VM fault */
+		return true;
+	}
+
+	adev->irq.ih.rptr += 16;
+	return false;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
index 65ed6d3..bd592cb 100644
--- a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
@@ -216,8 +216,23 @@ static u32 iceland_ih_get_wptr(struct amdgpu_device *adev)
  */
 static bool iceland_ih_prescreen_iv(struct amdgpu_device *adev)
 {
-	/* Process all interrupts */
-	return true;
+	u32 ring_index = adev->irq.ih.rptr >> 2;
+	u16 pasid;
+
+	switch (le32_to_cpu(adev->irq.ih.ring[ring_index]) & 0xff) {
+	case 146:
+	case 147:
+		pasid = le32_to_cpu(adev->irq.ih.ring[ring_index + 2]) >> 16;
+		if (!pasid || amdgpu_vm_pasid_fault_credit(adev, pasid))
+			return true;
+		break;
+	default:
+		/* Not a VM fault */
+		return true;
+	}
+
+	adev->irq.ih.rptr += 16;
+	return false;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
index 5ed0069..aa4e320 100644
--- a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
@@ -227,8 +227,23 @@ static u32 tonga_ih_get_wptr(struct amdgpu_device *adev)
  */
 static bool tonga_ih_prescreen_iv(struct amdgpu_device *adev)
 {
-	/* Process all interrupts */
-	return true;
+	u32 ring_index = adev->irq.ih.rptr >> 2;
+	u16 pasid;
+
+	switch (le32_to_cpu(adev->irq.ih.ring[ring_index]) & 0xff) {
+	case 146:
+	case 147:
+		pasid = le32_to_cpu(adev->irq.ih.ring[ring_index + 2]) >> 16;
+		if (!pasid || amdgpu_vm_pasid_fault_credit(adev, pasid))
+			return true;
+		break;
+	default:
+		/* Not a VM fault */
+		return true;
+	}
+
+	adev->irq.ih.rptr += 16;
+	return false;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
index a3b30d8..6973257 100644
--- a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
@@ -260,15 +260,18 @@ static bool vega10_ih_prescreen_iv(struct amdgpu_device *adev)
 		return true;
 	}
 
-	/* Not a retry fault */
-	if (!(dw5 & 0x80))
-		return true;
-
 	pasid = dw3 & 0xffff;
 	/* No PASID, can't identify faulting process */
 	if (!pasid)
 		return true;
 
+	/* Not a retry fault, check fault credit */
+	if (!(dw5 & 0x80)) {
+		if (!amdgpu_vm_pasid_fault_credit(adev, pasid))
+			goto ignore_iv;
+		return true;
+	}
+
 	addr = ((u64)(dw5 & 0xf) << 44) | ((u64)dw4 << 12);
 	key = AMDGPU_VM_FAULT(pasid, addr);
 	r = amdgpu_ih_add_fault(adev, key);