1 files changed, 35 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index bbcc67038203..fee0a32ac56f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2541,7 +2541,8 @@ static uint32_t amdgpu_vm_get_block_size(uint64_t vm_size)
  * @adev: amdgpu_device pointer
  * @fragment_size_default: the default fragment size if it's set auto
  */
-void amdgpu_vm_set_fragment_size(struct amdgpu_device *adev, uint32_t fragment_size_default)
+void amdgpu_vm_set_fragment_size(struct amdgpu_device *adev,
+                                 uint32_t fragment_size_default)
 {
         if (amdgpu_vm_fragment_size == -1)
                 adev->vm_manager.fragment_size = fragment_size_default;
@@ -2555,7 +2556,8 @@ void amdgpu_vm_set_fragment_size(struct amdgpu_device *adev, uint32_t fragment_s
  * @adev: amdgpu_device pointer
  * @vm_size: the default vm size if it's set auto
  */
-void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint64_t vm_size, uint32_t fragment_size_default)
+void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint64_t vm_size,
+                           uint32_t fragment_size_default)
 {
         /* adjust vm size firstly */
         if (amdgpu_vm_size == -1)
@@ -2682,6 +2684,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
         }
 
         INIT_KFIFO(vm->faults);
+        vm->fault_credit = 16;
 
         return 0;
 
@@ -2777,6 +2780,36 @@ 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