firewire: Use lib/ implementation of CRC ITU-T.

With the CRC ITU-T implementation available in lib/ we can use that instead.

This also fixes a bug in the topology map crc computation.

Signed-off-by: Kristian Hoegsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (fixed Kconfig)

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;