IB/mad: Create a generic helper for DR SMP Send processing

IB and OPA SMPs share the same processing algorithm but have different header
formats and permissive LID detection.

Add a helper function which is generic to processing DR SMP Send messages which
can be used by both IB and OPA SMP code.

Use this function in the current IB function smi_handle_dr_smp_send.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/smi.c

@@ -39,84 +39,80 @@
 #include <rdma/ib_smi.h>
 #include "smi.h"
 
-/*
- * Fixup a directed route SMP for sending
- * Return IB_SMI_DISCARD if the SMP should be discarded
- */
-enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
-				       u8 node_type, int port_num)
+static enum smi_action __smi_handle_dr_smp_send(u8 node_type, int port_num,
+						u8 *hop_ptr, u8 hop_cnt,
+						const u8 *initial_path,
+						const u8 *return_path,
+						u8 direction,
+						bool dr_dlid_is_permissive,
+						bool dr_slid_is_permissive)
 {
-	u8 hop_ptr, hop_cnt;
-
-	hop_ptr = smp->hop_ptr;
-	hop_cnt = smp->hop_cnt;
-
 	/* See section 14.2.2.2, Vol 1 IB spec */
 	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
 	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
 		return IB_SMI_DISCARD;
 
-	if (!ib_get_smp_direction(smp)) {
+	if (!direction) {
 		/* C14-9:1 */
-		if (hop_cnt && hop_ptr == 0) {
-			smp->hop_ptr++;
-			return (smp->initial_path[smp->hop_ptr] ==
+		if (hop_cnt && *hop_ptr == 0) {
+			(*hop_ptr)++;
+			return (initial_path[*hop_ptr] ==
 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-9:2 */
-		if (hop_ptr && hop_ptr < hop_cnt) {
+		if (*hop_ptr && *hop_ptr < hop_cnt) {
 			if (node_type != RDMA_NODE_IB_SWITCH)
 				return IB_SMI_DISCARD;
 
-			/* smp->return_path set when received */
-			smp->hop_ptr++;
-			return (smp->initial_path[smp->hop_ptr] ==
+			/* return_path set when received */
+			(*hop_ptr)++;
+			return (initial_path[*hop_ptr] ==
 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-9:3 -- We're at the end of the DR segment of path */
-		if (hop_ptr == hop_cnt) {
-			/* smp->return_path set when received */
-			smp->hop_ptr++;
+		if (*hop_ptr == hop_cnt) {
+			/* return_path set when received */
+			(*hop_ptr)++;
 			return (node_type == RDMA_NODE_IB_SWITCH ||
-				smp->dr_dlid == IB_LID_PERMISSIVE ?
+				dr_dlid_is_permissive ?
 				IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
 		/* C14-9:5 -- Fail unreasonable hop pointer */
-		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
+		return (*hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
 
 	} else {
 		/* C14-13:1 */
-		if (hop_cnt && hop_ptr == hop_cnt + 1) {
-			smp->hop_ptr--;
-			return (smp->return_path[smp->hop_ptr] ==
+		if (hop_cnt && *hop_ptr == hop_cnt + 1) {
+			(*hop_ptr)--;
+			return (return_path[*hop_ptr] ==
 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-13:2 */
-		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
+		if (2 <= *hop_ptr && *hop_ptr <= hop_cnt) {
 			if (node_type != RDMA_NODE_IB_SWITCH)
 				return IB_SMI_DISCARD;
 
-			smp->hop_ptr--;
-			return (smp->return_path[smp->hop_ptr] ==
+			(*hop_ptr)--;
+			return (return_path[*hop_ptr] ==
 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-13:3 -- at the end of the DR segment of path */
-		if (hop_ptr == 1) {
-			smp->hop_ptr--;
+		if (*hop_ptr == 1) {
+			(*hop_ptr)--;
 			/* C14-13:3 -- SMPs destined for SM shouldn't be here */
 			return (node_type == RDMA_NODE_IB_SWITCH ||
-				smp->dr_slid == IB_LID_PERMISSIVE ?
+				dr_slid_is_permissive ?
 				IB_SMI_HANDLE : IB_SMI_DISCARD);
 		}
 
 		/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
-		if (hop_ptr == 0)
+		if (*hop_ptr == 0)
 			return IB_SMI_HANDLE;
 
 		/* C14-13:5 -- Check for unreasonable hop pointer */
@@ -124,6 +120,22 @@ enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
 	}
 }
 
+/*
+ * Fixup a directed route SMP for sending
+ * Return IB_SMI_DISCARD if the SMP should be discarded
+ */
+enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
+				       u8 node_type, int port_num)
+{
+	return __smi_handle_dr_smp_send(node_type, port_num,
+					&smp->hop_ptr, smp->hop_cnt,
+					smp->initial_path,
+					smp->return_path,
+					ib_get_smp_direction(smp),
+					smp->dr_dlid == IB_LID_PERMISSIVE,
+					smp->dr_slid == IB_LID_PERMISSIVE);
+}
+
 /*
  * Adjust information for a received SMP
  * Return IB_SMI_DISCARD if the SMP should be dropped