[PATCH 5.9 29/49] ch_ktls: fix build warning for ipv4-only config

[Greg Kroah-Hartman]

From: Arnd Bergmann <a...@arndb.de>

[ Upstream commit a54ba3465d86fa5dd7d41bb88c0b5e71fb3b627e ]

When CONFIG_IPV6 is disabled, clang complains that a variable
is uninitialized for non-IPv4 data:

drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c:1046:6: error: 
variable 'cntrl1' is used uninitialized whenever 'if' condition is false 
[-Werror,-Wsometimes-uninitialized]
        if (tx_info->ip_family == AF_INET) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c:1059:2: note: 
uninitialized use occurs here
        cntrl1 |= T6_TXPKT_ETHHDR_LEN_V(maclen - ETH_HLEN) |
        ^~~~~~

Replace the preprocessor conditional with the corresponding C version,
and make the ipv4 case unconditional in this configuration to improve
readability and avoid the warning.

Fixes: 86716b51d14f ("ch_ktls: Update cheksum information")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
Link: https://lore.kernel.org/r/20201203222641.964234-1-a...@kernel.org
Signed-off-by: Jakub Kicinski <k...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/crypto/chelsio/chcr_ktls.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/drivers/crypto/chelsio/chcr_ktls.c
+++ b/drivers/crypto/chelsio/chcr_ktls.c
@@ -921,9 +921,7 @@ chcr_ktls_write_tcp_options(struct chcr_
        struct fw_eth_tx_pkt_wr *wr;
        struct cpl_tx_pkt_core *cpl;
        u32 ctrl, iplen, maclen;
-#if IS_ENABLED(CONFIG_IPV6)
        struct ipv6hdr *ip6;
-#endif
        unsigned int ndesc;
        struct tcphdr *tcp;
        int len16, pktlen;
@@ -971,17 +969,15 @@ chcr_ktls_write_tcp_options(struct chcr_
        cpl->len = htons(pktlen);
 
        memcpy(buf, skb->data, pktlen);
-       if (tx_info->ip_family == AF_INET) {
+       if (!IS_ENABLED(CONFIG_IPV6) || tx_info->ip_family == AF_INET) {
                /* we need to correct ip header len */
                ip = (struct iphdr *)(buf + maclen);
                ip->tot_len = htons(pktlen - maclen);
                cntrl1 = TXPKT_CSUM_TYPE_V(TX_CSUM_TCPIP);
-#if IS_ENABLED(CONFIG_IPV6)
        } else {
                ip6 = (struct ipv6hdr *)(buf + maclen);
                ip6->payload_len = htons(pktlen - maclen - iplen);
                cntrl1 = TXPKT_CSUM_TYPE_V(TX_CSUM_TCPIP6);
-#endif
        }
 
        cntrl1 |= T6_TXPKT_ETHHDR_LEN_V(maclen - ETH_HLEN) |