IB/srp: Wrap OUI checking for workarounds in helper functions

Wrap the checking for Mellanox and Topspin OUIs to decide whether to
use a workaround into helper functions.  This will make it cleaner to
add a new OUI to check (as we need to do now that some targets with a
Cisco OUI still need the Topspin workarounds).
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -75,16 +75,12 @@ module_param(topspin_workarounds, int, 0444);
 MODULE_PARM_DESC(topspin_workarounds,
 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
 
-static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
-
 static int mellanox_workarounds = 1;
 
 module_param(mellanox_workarounds, int, 0444);
 MODULE_PARM_DESC(mellanox_workarounds,
 		 "Enable workarounds for Mellanox SRP target bugs if != 0");
 
-static const u8 mellanox_oui[3] = { 0x00, 0x02, 0xc9 };
-
 static void srp_add_one(struct ib_device *device);
 static void srp_remove_one(struct ib_device *device);
 static void srp_completion(struct ib_cq *cq, void *target_ptr);
@@ -108,6 +104,22 @@ static const char *srp_target_info(struct Scsi_Host *host)
 	return host_to_target(host)->target_name;
 }
 
+static int srp_target_is_topspin(struct srp_target_port *target)
+{
+	static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
+
+	return topspin_workarounds &&
+		!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui);
+}
+
+static int srp_target_is_mellanox(struct srp_target_port *target)
+{
+	static const u8 mellanox_oui[3] = { 0x00, 0x02, 0xc9 };
+
+	return mellanox_workarounds &&
+		!memcmp(&target->ioc_guid, mellanox_oui, sizeof mellanox_oui);
+}
+
 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
 				   gfp_t gfp_mask,
 				   enum dma_data_direction direction)
@@ -360,7 +372,7 @@ static int srp_send_req(struct srp_target_port *target)
 	 * zero out the first 8 bytes of our initiator port ID and set
 	 * the second 8 bytes to the local node GUID.
 	 */
-	if (topspin_workarounds && !memcmp(&target->ioc_guid, topspin_oui, 3)) {
+	if (srp_target_is_topspin(target)) {
 		printk(KERN_DEBUG PFX "Topspin/Cisco initiator port ID workaround "
 		       "activated for target GUID %016llx\n",
 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
@@ -585,8 +597,8 @@ static int srp_map_fmr(struct srp_target_port *target, struct scatterlist *scat,
 	if (!dev->fmr_pool)
 		return -ENODEV;
 
-	if ((ib_sg_dma_address(ibdev, &scat[0]) & ~dev->fmr_page_mask) &&
-	    mellanox_workarounds && !memcmp(&target->ioc_guid, mellanox_oui, 3))
+	if (srp_target_is_mellanox(target) &&
+	    (ib_sg_dma_address(ibdev, &scat[0]) & ~dev->fmr_page_mask))
 		return -EINVAL;
 
 	len = page_cnt = 0;
@@ -1087,8 +1099,7 @@ static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
 		break;
 
 	case IB_CM_REJ_PORT_REDIRECT:
-		if (topspin_workarounds &&
-		    !memcmp(&target->ioc_guid, topspin_oui, 3)) {
+		if (srp_target_is_topspin(target)) {
 			/*
 			 * Topspin/Cisco SRP gateways incorrectly send
 			 * reject reason code 25 when they mean 24