From: Ahmad Fatoum Date: Thu, 3 Mar 2022 08:27:55 +0100 Subject: [PATCH] net: add ethaddr sequence handling Instead of storing every MAC address in full, boards may elect to store a base address and increment it N times. Add a helper to iterate over such an Ethernet address sequence. Example usage: const u8 *eth_addr; u8 eth_base[ETH_ALEN] = "\x00\x01\x02\x03\x04\x05"; int i = 0, eth_count = 4; for_each_seq_ethaddr(eth_addr, eth_base, ð_count) eth_register_ethaddr(i++, eth_addr); Signed-off-by: Ahmad Fatoum Upstream-Status: Submitted [https://lore.kernel.org/all/20250411074045.2019372-1-a.fatoum@pengutronix.de/] --- include/net.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/net.h b/include/net.h index a04ed5b0ab92..8a943e1bb1b2 100644 --- a/include/net.h +++ b/include/net.h @@ -516,6 +516,26 @@ static inline void eth_addr_add(u8 *addr, long offset) u64_to_ether_addr(u, addr); } +#define for_each_seq_ethaddr(eth_addr, eth_base, eth_count) \ + for (eth_addr = *eth_count ? eth_base : NULL; eth_addr; eth_addr = eth_addr_seq_next(eth_base, eth_count)) + +static inline const u8 *eth_addr_seq_next(u8 eth_base[6], unsigned *eth_count) +{ + __be64 eth_addr64 = 0; + void *eth_addr = (u8 *)ð_addr64 + 2; + + if (--(*eth_count) <= 0) + return NULL; + + memcpy(eth_addr, eth_base, ETH_ALEN); + + eth_addr64 = cpu_to_be64(be64_to_cpu(eth_addr64) + 1); + + memcpy(eth_base, eth_addr, ETH_ALEN); + + return eth_base; +} + typedef void rx_handler_f(void *ctx, char *packet, unsigned int len); struct eth_device *eth_get_byname(const char *name);