drm/amdgpu: Optimize a function called by every IB sheduling

  Move several if statements and a loop statment from
  run time to initialization time.
Signed-off-by: Alex Xie <AlexBin.Xie@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -152,6 +152,36 @@ void amdgpu_ring_undo(struct amdgpu_ring *ring)
 		ring->funcs->end_use(ring);
 }
 
+/**
+ * amdgpu_ring_check_compute_vm_bug - check whether this ring has compute vm bug
+ *
+ * @adev: amdgpu_device pointer
+ * @ring: amdgpu_ring structure holding ring information
+ */
+static void amdgpu_ring_check_compute_vm_bug(struct amdgpu_device *adev,
+					struct amdgpu_ring *ring)
+{
+	const struct amdgpu_ip_block *ip_block;
+
+	ring->has_compute_vm_bug = false;
+
+	if (ring->funcs->type != AMDGPU_RING_TYPE_COMPUTE)
+		/* only compute rings */
+		return;
+
+	ip_block = amdgpu_get_ip_block(adev, AMD_IP_BLOCK_TYPE_GFX);
+	if (!ip_block)
+		return;
+
+	/* Compute ring has a VM bug for GFX version < 7.
+           And compute ring has a VM bug for GFX 8 MEC firmware version < 673.*/
+	if (ip_block->version->major <= 7) {
+		ring->has_compute_vm_bug = true;
+	} else if (ip_block->version->major == 8)
+		if (adev->gfx.mec_fw_version < 673)
+			ring->has_compute_vm_bug = true;
+}
+
 /**
  * amdgpu_ring_init - init driver ring struct.
  *
@@ -257,6 +287,9 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 	if (amdgpu_debugfs_ring_init(adev, ring)) {
 		DRM_ERROR("Failed to register debugfs file for rings !\n");
 	}
+
+	amdgpu_ring_check_compute_vm_bug(adev, ring);
+
 	return 0;
 }
 

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

@@ -185,6 +185,7 @@ struct amdgpu_ring {
 	u64			cond_exe_gpu_addr;
 	volatile u32		*cond_exe_cpu_addr;
 	unsigned		vm_inv_eng;
+	bool			has_compute_vm_bug;
 #if defined(CONFIG_DEBUG_FS)
 	struct dentry *ent;
 #endif
@@ -207,4 +208,9 @@ static inline void amdgpu_ring_clear_ring(struct amdgpu_ring *ring)
 
 }
 
+static inline bool amdgpu_ring_has_compute_vm_bug(struct amdgpu_ring *ring)
+{
+	return ring->has_compute_vm_bug;
+}
+
 #endif

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

@@ -656,32 +656,6 @@ static int amdgpu_vm_alloc_reserved_vmid(struct amdgpu_device *adev,
 	return r;
 }
 
-static bool amdgpu_vm_ring_has_compute_vm_bug(struct amdgpu_ring *ring)
-{
-	struct amdgpu_device *adev = ring->adev;
-	const struct amdgpu_ip_block *ip_block;
-
-	if (ring->funcs->type != AMDGPU_RING_TYPE_COMPUTE)
-		/* only compute rings */
-		return false;
-
-	ip_block = amdgpu_get_ip_block(adev, AMD_IP_BLOCK_TYPE_GFX);
-	if (!ip_block)
-		return false;
-
-	if (ip_block->version->major <= 7) {
-		/* gfx7 has no workaround */
-		return true;
-	} else if (ip_block->version->major == 8) {
-		if (adev->gfx.mec_fw_version >= 673)
-			/* gfx8 is fixed in MEC firmware 673 */
-			return false;
-		else
-			return true;
-	}
-	return false;
-}
-
 bool amdgpu_vm_need_pipeline_sync(struct amdgpu_ring *ring,
 				  struct amdgpu_job *job)
 {
@@ -691,7 +665,7 @@ bool amdgpu_vm_need_pipeline_sync(struct amdgpu_ring *ring,
 	struct amdgpu_vm_id *id;
 	bool gds_switch_needed;
 	bool vm_flush_needed = job->vm_needs_flush ||
-		amdgpu_vm_ring_has_compute_vm_bug(ring);
+		amdgpu_ring_has_compute_vm_bug(ring);
 
 	if (job->vm_id == 0)
 		return false;