The MAPv4 packet format adds support for RX / TX checksum offload.
For a bi-directional UDP stream at a rate of 570 / 146 Mbps, roughly
10% CPU cycles are saved.
For receive path, there is a checksum trailer appended to the end of
the MAP packet. The valid field indicates if hardware has computed
the checksum. csum_start_offset indicates the offset from the start
of the IP header from which hardware has computed checksum.
csum_length is the number of bytes over which the checksum was
computed and the resulting value is csum_value.
In the transmit path, a header is appended between the end of the MAP
header and the start of the IP packet. csum_start_offset is the offset
in bytes from which hardware will compute the checksum if the
csum_enabled bit is set. udp_ip4_ind indicates if the checksum
value of 0 is valid or not. csum_insert_offset is the offset from the
csum_start_offset where hardware will insert the computed checksum.
The use of this additional packet format for checksum offload is
explained in subsequent patches.
Signed-off-by: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
---
drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h | 16 ++++++++++++++++
drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h | 2 ++
2 files changed, 18 insertions(+)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
index ef0eff2..50c50cd 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h
@@ -47,6 +47,22 @@ struct rmnet_map_header {
u16 pkt_len;
} __aligned(1);
+struct rmnet_map_dl_csum_trailer {
+ u8 reserved1;
+ u8 valid:1;
+ u8 reserved2:7;
+ u16 csum_start_offset;
+ u16 csum_length;
+ __be16 csum_value;
+} __aligned(1);
+
+struct rmnet_map_ul_csum_header {
+ __be16 csum_start_offset;
+ u16 csum_insert_offset:14;
+ u16 udp_ip4_ind:1;
+ u16 csum_enabled:1;
+} __aligned(1);
+
#define RMNET_MAP_GET_MUX_ID(Y) (((struct rmnet_map_header *) \
(Y)->data)->mux_id)
#define RMNET_MAP_GET_CD_BIT(Y) (((struct rmnet_map_header *) \
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h
b/drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h
index d214280..de0143e 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h
@@ -21,6 +21,8 @@
/* Constants */
#define RMNET_INGRESS_FORMAT_DEAGGREGATION BIT(0)
#define RMNET_INGRESS_FORMAT_MAP_COMMANDS BIT(1)
+#define RMNET_INGRESS_FORMAT_MAP_CKSUMV4 BIT(2)
+#define RMNET_EGRESS_FORMAT_MAP_CKSUMV4 BIT(3)
/* Replace skb->dev to a virtual rmnet device and pass up the stack */
#define RMNET_EPMODE_VND (1)
--
1.9.1
