[PATCH net-next v2 6/6] net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum header
From: Alex Elder <hidden>
Date: 2021-03-06 03:17:19
Also in:
lkml
Subsystem:
networking drivers, qualcomm rmnet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Subash Abhinov Kasiviswanathan, Sean Tranchetti, Linus Torvalds
Replace the use of C bit-fields in the rmnet_map_ul_csum_header structure with a single two-byte (big endian) structure member, and use field masks to encode or get values within it. Previously rmnet_map_ipv4_ul_csum_header() would update values in the host byte-order fields, and then forcibly fix their byte order using a combination of byte order operations and types. Instead, just compute the value that needs to go into the new structure member and save it with a simple byte-order conversion. Make similar simplifications in rmnet_map_ipv6_ul_csum_header(). Finally, in rmnet_map_checksum_uplink_packet() a set of assignments zeroes every field in the upload checksum header. Replace that with a single memset() operation. Signed-off-by: Alex Elder <redacted> Reported-by: kernel test robot <redacted> --- v2: Fixed to use u16_encode_bits() instead of be16_encode_bits(). .../ethernet/qualcomm/rmnet/rmnet_map_data.c | 34 ++++++------------- include/linux/if_rmnet.h | 21 ++++++------ 2 files changed, 21 insertions(+), 34 deletions(-)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index 29d485b868a65..b76ad48da7325 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c@@ -198,23 +198,19 @@ rmnet_map_ipv4_ul_csum_header(void *iphdr, struct rmnet_map_ul_csum_header *ul_header, struct sk_buff *skb) { - __be16 *hdr = (__be16 *)ul_header; struct iphdr *ip4h = iphdr; u16 offset; + u16 val; offset = skb_transport_header(skb) - (unsigned char *)iphdr; ul_header->csum_start_offset = htons(offset); - ul_header->csum_insert_offset = skb->csum_offset; - ul_header->csum_enabled = 1; + val = u16_encode_bits(1, MAP_CSUM_UL_ENABLED_FMASK); if (ip4h->protocol == IPPROTO_UDP) - ul_header->udp_ind = 1; - else - ul_header->udp_ind = 0; + val |= u16_encode_bits(1, MAP_CSUM_UL_UDP_FMASK); + val |= u16_encode_bits(skb->csum_offset, MAP_CSUM_UL_OFFSET_FMASK); - /* Changing remaining fields to network order */ - hdr++; - *hdr = htons((__force u16)*hdr); + ul_header->csum_info = htons(val); skb->ip_summed = CHECKSUM_NONE;
@@ -241,24 +237,19 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr, struct rmnet_map_ul_csum_header *ul_header, struct sk_buff *skb) { - __be16 *hdr = (__be16 *)ul_header; struct ipv6hdr *ip6h = ip6hdr; u16 offset; + u16 val; offset = skb_transport_header(skb) - (unsigned char *)ip6hdr; ul_header->csum_start_offset = htons(offset); - ul_header->csum_insert_offset = skb->csum_offset; - ul_header->csum_enabled = 1; - + val = u16_encode_bits(1, MAP_CSUM_UL_ENABLED_FMASK); if (ip6h->nexthdr == IPPROTO_UDP) - ul_header->udp_ind = 1; - else - ul_header->udp_ind = 0; + val |= u16_encode_bits(1, MAP_CSUM_UL_UDP_FMASK); + val |= u16_encode_bits(skb->csum_offset, MAP_CSUM_UL_OFFSET_FMASK); - /* Changing remaining fields to network order */ - hdr++; - *hdr = htons((__force u16)*hdr); + ul_header->csum_info = htons(val); skb->ip_summed = CHECKSUM_NONE;
@@ -425,10 +416,7 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb, } sw_csum: - ul_header->csum_start_offset = 0; - ul_header->csum_insert_offset = 0; - ul_header->csum_enabled = 0; - ul_header->udp_ind = 0; + memset(ul_header, 0, sizeof(*ul_header)); priv->stats.csum_sw++; }
diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h
index 1fbb7531238b6..9ff09a2bcf9e1 100644
--- a/include/linux/if_rmnet.h
+++ b/include/linux/if_rmnet.h@@ -33,17 +33,16 @@ struct rmnet_map_dl_csum_trailer { struct rmnet_map_ul_csum_header { __be16 csum_start_offset; -#if defined(__LITTLE_ENDIAN_BITFIELD) - u16 csum_insert_offset:14; - u16 udp_ind:1; - u16 csum_enabled:1; -#elif defined (__BIG_ENDIAN_BITFIELD) - u16 csum_enabled:1; - u16 udp_ind:1; - u16 csum_insert_offset:14; -#else -#error "Please fix <asm/byteorder.h>" -#endif + __be16 csum_info; /* MAP_CSUM_UL_*_FMASK */ } __aligned(1); +/* csum_info field: + * OFFSET: where (offset in bytes) to insert computed checksum + * UDP: 1 = UDP checksum (zero checkum means no checksum) + * ENABLED: 1 = checksum computation requested + */ +#define MAP_CSUM_UL_OFFSET_FMASK GENMASK(13, 0) +#define MAP_CSUM_UL_UDP_FMASK GENMASK(14, 14) +#define MAP_CSUM_UL_ENABLED_FMASK GENMASK(15, 15) + #endif /* !(_LINUX_IF_RMNET_H_) */
--
2.27.0