[PATCH net v2] nfp: fix swapped arguments in nfp_encode_basic_qdr() calls

[Alexey Kodanev <aleksei.kodanev@bell-sw.com>]

There is a mismatch between the passed arguments and the actual
nfp_encode_basic_qdr() function parameter names:

  static int nfp_encode_basic_qdr(u64 addr, int dest_island, int cpp_tgt,
                                  int mode, bool addr40, int isld1,
                                  int isld0)
  {
      ...

But "dest_island" and "cpp_tgt" are swapped at every call-site.
For example:

  return nfp_encode_basic_qdr(*addr, cpp_tgt, dest_island,
                              mode, addr40, isld1, isld0);

As a result, nfp_encode_basic_qdr() receives "dest_island" as CPP target
type, which is always NFP_CPP_TARGET_QDR(2) for these calls, and "cpp_tgt"
as the destination island ID, which can accidentally match or be outside
the valid NFP_CPP_TARGET_* types (e.g. '-1' for any destination).

Since code already worked for years, also add extra pr_warn() to error
paths in nfp_encode_basic_qdr() to help identify any potential address
verification failures.

Detected using the static analysis tool - Svace.

Fixes: 4cb584e0ee7d ("nfp: add CPP access core")
Signed-off-by: Alexey Kodanev <aleksei.kodanev@bell-sw.com>
---

v2: tag patch for "net"
    add extra warnings to nfp_encode_basic_qdr() error paths

 .../ethernet/netronome/nfp/nfpcore/nfp_target.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_target.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_target.c
index 79470f198a62..9cf19446657c 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_target.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_target.c
@@ -435,12 +435,17 @@ static int nfp_encode_basic_qdr(u64 addr, int dest_island, int cpp_tgt,
 
 	/* Full Island ID and channel bits overlap? */
 	ret = nfp_decode_basic(addr, &v, cpp_tgt, mode, addr40, isld1, isld0);
-	if (ret)
+	if (ret) {
+		pr_warn("%s: decode dest_island failed: %d\n", __func__, ret);
 		return ret;
+	}
 
 	/* The current address won't go where expected? */
-	if (dest_island != -1 && dest_island != v)
+	if (dest_island != -1 && dest_island != v) {
+		pr_warn("%s: dest_island mismatch: current (%d) != decoded (%d)\n",
+			__func__, dest_island, v);
 		return -EINVAL;
+	}
 
 	/* If dest_island was -1, we don't care where it goes. */
 	return 0;
@@ -493,7 +498,7 @@ static int nfp_encode_basic(u64 *addr, int dest_island, int cpp_tgt,
 			 * the address but we can verify if the existing
 			 * contents will point to a valid island.
 			 */
-			return nfp_encode_basic_qdr(*addr, cpp_tgt, dest_island,
+			return nfp_encode_basic_qdr(*addr, dest_island, cpp_tgt,
 						    mode, addr40, isld1, isld0);
 
 		iid_lsb = addr40 ? 34 : 26;
@@ -504,7 +509,7 @@ static int nfp_encode_basic(u64 *addr, int dest_island, int cpp_tgt,
 		return 0;
 	case 1:
 		if (cpp_tgt == NFP_CPP_TARGET_QDR && !addr40)
-			return nfp_encode_basic_qdr(*addr, cpp_tgt, dest_island,
+			return nfp_encode_basic_qdr(*addr, dest_island, cpp_tgt,
 						    mode, addr40, isld1, isld0);
 
 		idx_lsb = addr40 ? 39 : 31;
@@ -530,7 +535,7 @@ static int nfp_encode_basic(u64 *addr, int dest_island, int cpp_tgt,
 			 * be set before hand and with them select an island.
 			 * So we need to confirm that it's at least plausible.
 			 */
-			return nfp_encode_basic_qdr(*addr, cpp_tgt, dest_island,
+			return nfp_encode_basic_qdr(*addr, dest_island, cpp_tgt,
 						    mode, addr40, isld1, isld0);
 
 		/* Make sure we compare against isldN values
@@ -551,7 +556,7 @@ static int nfp_encode_basic(u64 *addr, int dest_island, int cpp_tgt,
 			 * iid<1> = addr<30> = channel<0>
 			 * channel<1> = addr<31> = Index
 			 */
-			return nfp_encode_basic_qdr(*addr, cpp_tgt, dest_island,
+			return nfp_encode_basic_qdr(*addr, dest_island, cpp_tgt,
 						    mode, addr40, isld1, isld0);
 
 		isld[0] &= ~3;
-- 
2.25.1