From: Alex Elder <elder@linaro.org>
To: subashab@codeaurora.org, stranche@codeaurora.org,
davem@davemloft.net, kuba@kernel.org
Cc: bjorn.andersson@linaro.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH net-next 7/8] net: qualcomm: rmnet: drop some unary NOTs
Date: Sat, 12 Jun 2021 09:37:35 -0500 [thread overview]
Message-ID: <20210612143736.3498712-8-elder@linaro.org> (raw)
In-Reply-To: <20210612143736.3498712-1-elder@linaro.org>
We compare a payload checksum with a pseudo checksum value for
equality in rmnet_map_ipv4_dl_csum_trailer(). Both of those values
are computed with a unary NOT (~) operation. The result of the
comparison is the same if we omit that NOT for both values.
Remove these operations in rmnet_map_ipv6_dl_csum_trailer() also.
Signed-off-by: Alex Elder <elder@linaro.org>
---
.../net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index 610c8b5a8f46a..ed4737d0043d6 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -87,11 +87,11 @@ rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb,
* header checksum value; it is already accounted for in the
* checksum value found in the trailer.
*/
- ip_payload_csum = ~csum_trailer->csum_value;
+ ip_payload_csum = csum_trailer->csum_value;
- pseudo_csum = ~csum_tcpudp_magic(ip4h->saddr, ip4h->daddr,
- ntohs(ip4h->tot_len) - ip4h->ihl * 4,
- ip4h->protocol, 0);
+ pseudo_csum = csum_tcpudp_magic(ip4h->saddr, ip4h->daddr,
+ ntohs(ip4h->tot_len) - ip4h->ihl * 4,
+ ip4h->protocol, 0);
/* The cast is required to ensure only the low 16 bits are examined */
if (ip_payload_csum != (__sum16)~pseudo_csum) {
@@ -132,13 +132,13 @@ rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb,
* checksum computed over the pseudo header.
*/
ip_header_csum = (__force __be16)ip_fast_csum(ip6h, sizeof(*ip6h) / 4);
- ip6_payload_csum = ~csum16_sub(csum_trailer->csum_value, ip_header_csum);
+ ip6_payload_csum = csum16_sub(csum_trailer->csum_value, ip_header_csum);
length = (ip6h->nexthdr == IPPROTO_UDP) ?
ntohs(((struct udphdr *)txporthdr)->len) :
ntohs(ip6h->payload_len);
- pseudo_csum = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
- length, ip6h->nexthdr, 0);
+ pseudo_csum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ length, ip6h->nexthdr, 0);
/* It's sufficient to compare the IP payload checksum with the
* negated pseudo checksum to determine whether the packet
--
2.27.0
next prev parent reply other threads:[~2021-06-12 14:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-12 14:37 [PATCH net-next 0/8] net: qualcomm: rmnet: MAPv4 download checksum cleanup, part 2 Alex Elder
2021-06-12 14:37 ` [PATCH net-next 1/8] net: qualcomm: rmnet: remove some local variables Alex Elder
2021-06-12 14:37 ` [PATCH net-next 2/8] net: qualcomm: rmnet: rearrange some NOTs Alex Elder
2021-06-12 14:37 ` [PATCH net-next 3/8] net: qualcomm: rmnet: show that an intermediate sum is zero Alex Elder
2021-06-12 14:37 ` [PATCH net-next 4/8] net: qualcomm: rmnet: return earlier for bad checksum Alex Elder
2021-06-12 14:37 ` [PATCH net-next 5/8] net: qualcomm: rmnet: remove unneeded code Alex Elder
2021-06-12 14:37 ` [PATCH net-next 6/8] net: qualcomm: rmnet: trailer value is a checksum Alex Elder
2021-06-12 14:37 ` Alex Elder [this message]
2021-06-12 14:37 ` [PATCH net-next 8/8] net: qualcomm: rmnet: IPv6 payload length is simple Alex Elder
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