firewire: core: optimize Topology Map creation

The Topology Map of the local node was created in CPU byte order,
then a temporary big endian copy was created to compute the CRC,
and when a read request to the Topology Map arrived it had to be
converted to big endian byte order again.

We now generate it in big endian byte order in the first place.
This also rids us of 1000 bytes stack usage in tasklet context.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 2 insertions, 15 deletions

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index f58130789990..7083bcc1b9c7 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -38,7 +38,7 @@
 
 #include "core.h"
 
-static int __compute_block_crc(__be32 *block)
+int fw_compute_block_crc(__be32 *block)
 {
         int length;
         u16 crc;
@@ -50,19 +50,6 @@ static int __compute_block_crc(__be32 *block)
         return length;
 }
 
-int fw_compute_block_crc(u32 *block)
-{
-        __be32 be32_block[256];
-        int i, length;
-
-        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 DEFINE_MUTEX(card_mutex);
 static LIST_HEAD(card_list);
 
@@ -141,7 +128,7 @@ static size_t generate_config_rom(struct fw_card *card, __be32 *config_rom)
          * the bus info block, which is always the case for this
          * implementation. */
         for (i = 0; i < j; i += length + 1)
-                length = __compute_block_crc(config_rom + i);
+                length = fw_compute_block_crc(config_rom + i);
 
         return j;
 }