drm/amdgpu: add a helper function to decode iv

since from soc15, all the chips share the same
iv format. create a common helper to decode iv
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Dennis Li <Dennis.Li@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c

@@ -205,3 +205,46 @@ int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
 	return IRQ_HANDLED;
 }
 
+/**
+ * amdgpu_ih_decode_iv_helper - decode an interrupt vector
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Decodes the interrupt vector at the current rptr
+ * position and also advance the position for for Vega10
+ * and later GPUs.
+ */
+void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
+				struct amdgpu_ih_ring *ih,
+				struct amdgpu_iv_entry *entry)
+{
+	/* wptr/rptr are in bytes! */
+	u32 ring_index = ih->rptr >> 2;
+	uint32_t dw[8];
+
+	dw[0] = le32_to_cpu(ih->ring[ring_index + 0]);
+	dw[1] = le32_to_cpu(ih->ring[ring_index + 1]);
+	dw[2] = le32_to_cpu(ih->ring[ring_index + 2]);
+	dw[3] = le32_to_cpu(ih->ring[ring_index + 3]);
+	dw[4] = le32_to_cpu(ih->ring[ring_index + 4]);
+	dw[5] = le32_to_cpu(ih->ring[ring_index + 5]);
+	dw[6] = le32_to_cpu(ih->ring[ring_index + 6]);
+	dw[7] = le32_to_cpu(ih->ring[ring_index + 7]);
+
+	entry->client_id = dw[0] & 0xff;
+	entry->src_id = (dw[0] >> 8) & 0xff;
+	entry->ring_id = (dw[0] >> 16) & 0xff;
+	entry->vmid = (dw[0] >> 24) & 0xf;
+	entry->vmid_src = (dw[0] >> 31);
+	entry->timestamp = dw[1] | ((u64)(dw[2] & 0xffff) << 32);
+	entry->timestamp_src = dw[2] >> 31;
+	entry->pasid = dw[3] & 0xffff;
+	entry->pasid_src = dw[3] >> 31;
+	entry->src_data[0] = dw[4];
+	entry->src_data[1] = dw[5];
+	entry->src_data[2] = dw[6];
+	entry->src_data[3] = dw[7];
+
+	/* wptr/rptr are in bytes! */
+	ih->rptr += 32;
+}

drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h

@@ -88,5 +88,7 @@ void amdgpu_ih_ring_fini(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih);
 void amdgpu_ih_ring_write(struct amdgpu_ih_ring *ih, const uint32_t *iv,
 			  unsigned int num_dw);
 int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih);
-
+void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
+				struct amdgpu_ih_ring *ih,
+				struct amdgpu_iv_entry *entry);
 #endif