net: ipa: IPA status preparatory cleanups

The next patch reworks how the IPA packet status structure is
interpreted.  This patch does some preparatory work, to make it
easier to see the effect of that change:
  - Change a few functions that access fields in a IPA packet status
    structure to store field values in local variables with names
    related to the field.
  - Pass a void pointer rather than an (equivalent) status pointer
    to two functions called by ipa_endpoint_status_parse().
  - Use "rule" rather than "val" as the name of a variable that
    holds a routing rule ID.
  - Consistently use "IPA packet status" rather than "status
    element" when referring to this data structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_endpoint.c

@@ -1182,8 +1182,8 @@ static void ipa_endpoint_status(struct ipa_endpoint *endpoint)
 			val |= ipa_reg_encode(reg, STATUS_ENDP,
 					      status_endpoint_id);
 		}
-		/* STATUS_LOCATION is 0, meaning status element precedes
-		 * packet (not present for IPA v4.5+)
+		/* STATUS_LOCATION is 0, meaning IPA packet status
+		 * precedes the packet (not present for IPA v4.5+)
 		 */
 		/* STATUS_PKT_SUPPRESS_FMASK is 0 (not present for v4.0+) */
 	}
@@ -1339,8 +1339,8 @@ static bool ipa_endpoint_skb_build(struct ipa_endpoint *endpoint,
 	return skb != NULL;
 }
 
-/* The format of a packet status element is the same for several status
- * types (opcodes).  Other types aren't currently supported.
+ /* The format of an IPA packet status structure is the same for several
+  * status types (opcodes).  Other types aren't currently supported.
  */
 static bool ipa_status_format_packet(enum ipa_status_opcode opcode)
 {
@@ -1358,9 +1358,11 @@ static bool ipa_status_format_packet(enum ipa_status_opcode opcode)
 static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
 				     const struct ipa_status *status)
 {
+	enum ipa_status_opcode opcode;
 	u32 endpoint_id;
 
-	if (!ipa_status_format_packet(status->opcode))
+	opcode = status->opcode;
+	if (!ipa_status_format_packet(opcode))
 		return true;
 
 	endpoint_id = u8_get_bits(status->endp_dst_idx,
@@ -1371,14 +1373,16 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
 	return false;	/* Don't skip this packet, process it */
 }
 
-static bool ipa_endpoint_status_tag(struct ipa_endpoint *endpoint,
-				    const struct ipa_status *status)
+static bool ipa_endpoint_status_tag_valid(struct ipa_endpoint *endpoint,
+					  const struct ipa_status *status)
 {
 	struct ipa_endpoint *command_endpoint;
+	enum ipa_status_mask status_mask;
 	struct ipa *ipa = endpoint->ipa;
 	u32 endpoint_id;
 
-	if (!le16_get_bits(status->mask, IPA_STATUS_MASK_TAG_VALID))
+	status_mask = le16_get_bits(status->mask, IPA_STATUS_MASK_TAG_VALID);
+	if (!status_mask)
 		return false;	/* No valid tag */
 
 	/* The status contains a valid tag.  We know the packet was sent to
@@ -1404,20 +1408,23 @@ static bool ipa_endpoint_status_tag(struct ipa_endpoint *endpoint,
 static bool ipa_endpoint_status_drop(struct ipa_endpoint *endpoint,
 				     const struct ipa_status *status)
 {
-	u32 val;
+	enum ipa_status_exception exception;
+	u32 rule;
 
 	/* If the status indicates a tagged transfer, we'll drop the packet */
-	if (ipa_endpoint_status_tag(endpoint, status))
+	if (ipa_endpoint_status_tag_valid(endpoint, status))
 		return true;
 
 	/* Deaggregation exceptions we drop; all other types we consume */
-	if (status->exception)
-		return status->exception == IPA_STATUS_EXCEPTION_DEAGGR;
+	exception = status->exception;
+	if (exception)
+		return exception == IPA_STATUS_EXCEPTION_DEAGGR;
 
 	/* Drop the packet if it fails to match a routing rule; otherwise no */
-	val = le32_get_bits(status->flags1, IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+	rule = le32_get_bits(status->flags1,
+			     IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
 
-	return val == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+	return rule == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
 }
 
 static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
@@ -1443,15 +1450,15 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
 
 		/* Skip over status packets that lack packet data */
 		length = le16_to_cpu(status->pkt_len);
-		if (!length || ipa_endpoint_status_skip(endpoint, status)) {
+		if (!length || ipa_endpoint_status_skip(endpoint, data)) {
 			data += IPA_STATUS_SIZE;
 			resid -= IPA_STATUS_SIZE;
 			continue;
 		}
 
 		/* Compute the amount of buffer space consumed by the packet,
-		 * including the status element.  If the hardware is configured
-		 * to pad packet data to an aligned boundary, account for that.
+		 * including the status.  If the hardware is configured to
+		 * pad packet data to an aligned boundary, account for that.
 		 * And if checksum offload is enabled a trailer containing
 		 * computed checksum information will be appended.
 		 */
@@ -1460,7 +1467,7 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
 		if (endpoint->config.checksum)
 			len += sizeof(struct rmnet_map_dl_csum_trailer);
 
-		if (!ipa_endpoint_status_drop(endpoint, status)) {
+		if (!ipa_endpoint_status_drop(endpoint, data)) {
 			void *data2;
 			u32 extra;