diff options
Diffstat (limited to 'drivers/firewire/fw-card.c')
| -rw-r--r-- | drivers/firewire/fw-card.c | 35 |
1 files changed, 12 insertions, 23 deletions
diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c index a2de680d9d52..216965615ee8 100644 --- a/drivers/firewire/fw-card.c +++ b/drivers/firewire/fw-card.c @@ -23,31 +23,22 @@ #include <linux/errno.h> #include <linux/device.h> #include <linux/rwsem.h> +#include <linux/crc-itu-t.h> #include "fw-transaction.h" #include "fw-topology.h" #include "fw-device.h" -/* The lib/crc16.c implementation uses the standard (0x8005) - * polynomial, but we need the ITU-T (or CCITT) polynomial (0x1021). - * The implementation below works on an array of host-endian u32 - * words, assuming they'll be transmited msb first. */ -u16 -crc16_itu_t(const u32 *buffer, size_t length) +int fw_compute_block_crc(u32 *block) { - int shift, i; - u32 data; - u16 sum, crc = 0; - - for (i = 0; i < length; i++) { - data = *buffer++; - for (shift = 28; shift >= 0; shift -= 4 ) { - sum = ((crc >> 12) ^ (data >> shift)) & 0xf; - crc = (crc << 4) ^ (sum << 12) ^ (sum << 5) ^ (sum); - } - crc &= 0xffff; - } + __be32 be32_block[256]; + int i, length; - return crc; + length = (*block >> 16) & 0xff; + for (i = 0; i < length; i++) + be32_block[i] = cpu_to_be32(block[i + 1]); + *block |= crc_itu_t(0, (u8 *) be32_block, length * 4); + + return length; } static DECLARE_RWSEM(card_rwsem); @@ -126,10 +117,8 @@ generate_config_rom (struct fw_card *card, size_t *config_rom_length) * assumes that CRC length and info length are identical for * the bus info block, which is always the case for this * implementation. */ - for (i = 0; i < j; i += length + 1) { - length = (config_rom[i] >> 16) & 0xff; - config_rom[i] |= crc16_itu_t(&config_rom[i + 1], length); - } + for (i = 0; i < j; i += length + 1) + length = fw_compute_block_crc(config_rom + i); *config_rom_length = j; |