diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2026-03-17 01:14:53 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-19 05:07:37 +0300 |
| commit | d5516452a362aab2c136ab815967c4417c92d228 (patch) | |
| tree | 38d427245948d60fb748367dc8179e471ebfc2f3 /drivers | |
| parent | 4455a30b043ac2e20369b400a2132aaf127735e3 (diff) | |
| download | linux-d5516452a362aab2c136ab815967c4417c92d228.tar.xz | |
qed: Reimplement qed_mcast_bin_from_mac() using library functions
The calculation done by qed_calc_crc32c() is the standard
least-significant-bit-first CRC-32C except it uses
most-significant-bit-first order for the actual CRC variable. That is
equivalent to bit-reflecting the input and output CRC. Replace it with
equivalent calls to the corresponding library functions.
Tested with a simple userspace program which tested that the old and new
implementations of qed_mcast_bin_from_mac() produce the same outputs.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20260316221453.66078-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/qlogic/qed/qed_l2.c | 53 |
1 files changed, 11 insertions, 42 deletions
diff --git a/drivers/net/ethernet/qlogic/qed/qed_l2.c b/drivers/net/ethernet/qlogic/qed/qed_l2.c index 0f6905e33df6..2d873a596261 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_l2.c +++ b/drivers/net/ethernet/qlogic/qed/qed_l2.c @@ -7,6 +7,7 @@ #include <linux/types.h> #include <asm/byteorder.h> #include <asm/param.h> +#include <linux/crc32.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/etherdevice.h> @@ -39,7 +40,6 @@ #include "qed_sriov.h" #define QED_MAX_SGES_NUM 16 -#define CRC32_POLY 0x1edc6f41 struct qed_l2_info { u32 queues; @@ -1412,50 +1412,19 @@ int qed_sp_eth_filter_ucast(struct qed_hwfn *p_hwfn, return 0; } -/******************************************************************************* - * Description: - * Calculates crc 32 on a buffer - * Note: crc32_length MUST be aligned to 8 - * Return: - ******************************************************************************/ -static u32 qed_calc_crc32c(u8 *crc32_packet, - u32 crc32_length, u32 crc32_seed, u8 complement) -{ - u32 byte = 0, bit = 0, crc32_result = crc32_seed; - u8 msb = 0, current_byte = 0; - - if ((!crc32_packet) || - (crc32_length == 0) || - ((crc32_length % 8) != 0)) - return crc32_result; - for (byte = 0; byte < crc32_length; byte++) { - current_byte = crc32_packet[byte]; - for (bit = 0; bit < 8; bit++) { - msb = (u8)(crc32_result >> 31); - crc32_result = crc32_result << 1; - if (msb != (0x1 & (current_byte >> bit))) { - crc32_result = crc32_result ^ CRC32_POLY; - crc32_result |= 1; /*crc32_result[0] = 1;*/ - } - } - } - return crc32_result; -} - -static u32 qed_crc32c_le(u32 seed, u8 *mac, u32 len) -{ - u32 packet_buf[2] = { 0 }; - - memcpy((u8 *)(&packet_buf[0]), &mac[0], 6); - return qed_calc_crc32c((u8 *)packet_buf, 8, seed, 0); -} - u8 qed_mcast_bin_from_mac(u8 *mac) { - u32 crc = qed_crc32c_le(ETH_MULTICAST_BIN_FROM_MAC_SEED, - mac, ETH_ALEN); + u8 padded_mac[8] = {}; + u32 crc; - return crc & 0xff; + memcpy(padded_mac, mac, ETH_ALEN); + /* + * This uses the standard CRC-32C, but with the input and output CRCs + * bit-reflected and the bit-reflected output CRC truncated to 8 bits. + */ + crc = crc32c(bitrev32(ETH_MULTICAST_BIN_FROM_MAC_SEED), padded_mac, + sizeof(padded_mac)); + return bitrev8(crc >> 24); } static int |