cxgb4/chcr: avoid -Wreturn-local-addr warning

gcc-10 warns about functions that return a pointer to a stack
variable. In chcr_write_cpl_set_tcb_ulp(), this does not actually
happen, but it's too hard to see for the compiler:

drivers/crypto/chelsio/chcr_ktls.c: In function 'chcr_write_cpl_set_tcb_ulp.constprop':
drivers/crypto/chelsio/chcr_ktls.c:760:9: error: function may return address of local variable [-Werror=return-local-addr]
  760 |  return pos;
      |         ^~~
drivers/crypto/chelsio/chcr_ktls.c:712:5: note: declared here
  712 |  u8 buf[48] = {0};
      |     ^~~

Split the middle part of the function out into a helper to make
it easier to understand by both humans and compilers, which avoids
the warning.

Fixes: 5a4b9fe7fece ("cxgb4/chcr: complete record tx handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/crypto/chelsio/chcr_ktls.c b/drivers/crypto/chelsio/chcr_ktls.c
index e92b352..43d9e24 100644 (file)
--- a/drivers/crypto/chelsio/chcr_ktls.c
+++ b/drivers/crypto/chelsio/chcr_ktls.c
@@ -673,41 +673,14 @@ int chcr_ktls_cpl_set_tcb_rpl(struct adapter *adap, unsigned char *input)
        return 0;
 }
 
-/*
- * chcr_write_cpl_set_tcb_ulp: update tcb values.
- * TCB is responsible to create tcp headers, so all the related values
- * should be correctly updated.
- * @tx_info - driver specific tls info.
- * @q - tx queue on which packet is going out.
- * @tid - TCB identifier.
- * @pos - current index where should we start writing.
- * @word - TCB word.
- * @mask - TCB word related mask.
- * @val - TCB word related value.
- * @reply - set 1 if looking for TP response.
- * return - next position to write.
- */
-static void *chcr_write_cpl_set_tcb_ulp(struct chcr_ktls_info *tx_info,
-                                       struct sge_eth_txq *q, u32 tid,
-                                       void *pos, u16 word, u64 mask,
+static void *__chcr_write_cpl_set_tcb_ulp(struct chcr_ktls_info *tx_info,
+                                       u32 tid, void *pos, u16 word, u64 mask,
                                        u64 val, u32 reply)
 {
        struct cpl_set_tcb_field_core *cpl;
        struct ulptx_idata *idata;
        struct ulp_txpkt *txpkt;
-       void *save_pos = NULL;
-       u8 buf[48] = {0};
-       int left;
 
-       left = (void *)q->q.stat - pos;
-       if (unlikely(left < CHCR_SET_TCB_FIELD_LEN)) {
-               if (!left) {
-                       pos = q->q.desc;
-               } else {
-                       save_pos = pos;
-                       pos = buf;
-               }
-       }
        /* ULP_TXPKT */
        txpkt = pos;
        txpkt->cmd_dest = htonl(ULPTX_CMD_V(ULP_TX_PKT) | ULP_TXPKT_DEST_V(0));
@@ -732,18 +705,54 @@ static void *chcr_write_cpl_set_tcb_ulp(struct chcr_ktls_info *tx_info,
        idata = (struct ulptx_idata *)(cpl + 1);
        idata->cmd_more = htonl(ULPTX_CMD_V(ULP_TX_SC_NOOP));
        idata->len = htonl(0);
+       pos = idata + 1;
 
-       if (save_pos) {
-               pos = chcr_copy_to_txd(buf, &q->q, save_pos,
-                                      CHCR_SET_TCB_FIELD_LEN);
-       } else {
-               /* check again if we are at the end of the queue */
-               if (left == CHCR_SET_TCB_FIELD_LEN)
+       return pos;
+}
+
+
+/*
+ * chcr_write_cpl_set_tcb_ulp: update tcb values.
+ * TCB is responsible to create tcp headers, so all the related values
+ * should be correctly updated.
+ * @tx_info - driver specific tls info.
+ * @q - tx queue on which packet is going out.
+ * @tid - TCB identifier.
+ * @pos - current index where should we start writing.
+ * @word - TCB word.
+ * @mask - TCB word related mask.
+ * @val - TCB word related value.
+ * @reply - set 1 if looking for TP response.
+ * return - next position to write.
+ */
+static void *chcr_write_cpl_set_tcb_ulp(struct chcr_ktls_info *tx_info,
+                                       struct sge_eth_txq *q, u32 tid,
+                                       void *pos, u16 word, u64 mask,
+                                       u64 val, u32 reply)
+{
+       int left = (void *)q->q.stat - pos;
+
+       if (unlikely(left < CHCR_SET_TCB_FIELD_LEN)) {
+               if (!left) {
                        pos = q->q.desc;
-               else
-                       pos = idata + 1;
+               } else {
+                       u8 buf[48] = {0};
+
+                       __chcr_write_cpl_set_tcb_ulp(tx_info, tid, buf, word,
+                                                    mask, val, reply);
+
+                       return chcr_copy_to_txd(buf, &q->q, pos,
+                                               CHCR_SET_TCB_FIELD_LEN);
+               }
        }
 
+       pos = __chcr_write_cpl_set_tcb_ulp(tx_info, tid, pos, word,
+                                          mask, val, reply);
+
+       /* check again if we are at the end of the queue */
+       if (left == CHCR_SET_TCB_FIELD_LEN)
+               pos = q->q.desc;
+
        return pos;
 }