mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
16653c16d2
The actual layout of bits defined in C bit-fields (e.g. int foo : 3) is implementation-defined. Structures defined in <linux/if_rmnet.h> address this by specifying all bit-fields twice, to cover two possible layouts. I think this pattern is repetitive and noisy, and I find the whole notion of compiler "bitfield endianness" to be non-intuitive. Stop using C bit-fields for the command/data flag and the pad length fields in the rmnet_map structure, and define a single-byte flags field instead. Define a mask for the single-bit "command" flag, and another mask for the encoded pad length. The content of both fields can be accessed using a simple bitwise AND operation. Signed-off-by: Alex Elder <elder@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
52 lines
1.2 KiB
C
52 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only
|
|
* Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
|
|
*/
|
|
|
|
#ifndef _LINUX_IF_RMNET_H_
|
|
#define _LINUX_IF_RMNET_H_
|
|
|
|
struct rmnet_map_header {
|
|
u8 flags; /* MAP_CMD_FLAG, MAP_PAD_LEN_MASK */
|
|
u8 mux_id;
|
|
__be16 pkt_len; /* Length of packet, including pad */
|
|
} __aligned(1);
|
|
|
|
/* rmnet_map_header flags field:
|
|
* PAD_LEN: number of pad bytes following packet data
|
|
* CMD: 1 = packet contains a MAP command; 0 = packet contains data
|
|
*/
|
|
#define MAP_PAD_LEN_MASK GENMASK(5, 0)
|
|
#define MAP_CMD_FLAG BIT(7)
|
|
|
|
struct rmnet_map_dl_csum_trailer {
|
|
u8 reserved1;
|
|
#if defined(__LITTLE_ENDIAN_BITFIELD)
|
|
u8 valid:1;
|
|
u8 reserved2:7;
|
|
#elif defined (__BIG_ENDIAN_BITFIELD)
|
|
u8 reserved2:7;
|
|
u8 valid:1;
|
|
#else
|
|
#error "Please fix <asm/byteorder.h>"
|
|
#endif
|
|
__be16 csum_start_offset;
|
|
__be16 csum_length;
|
|
__be16 csum_value;
|
|
} __aligned(1);
|
|
|
|
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
|
|
} __aligned(1);
|
|
|
|
#endif /* !(_LINUX_IF_RMNET_H_) */
|