ieee1394: ohci1394: more obvious endianess handling

Rename ohci1394's packet_swab to header_le32_to_cpu to better reflect
what it actually does.  Also, define a constant array as 'const' and
check the array index properly.

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

1 files changed, 13 insertions, 14 deletions

diff --git a/drivers/ieee1394/ohci1394.c b/drivers/ieee1394/ohci1394.c
index 4622c99c12f2..8d92246bdc3b 100644
--- a/drivers/ieee1394/ohci1394.c
+++ b/drivers/ieee1394/ohci1394.c
@@ -181,36 +181,35 @@ static int alloc_dma_trm_ctx(struct ti_ohci *ohci, struct dma_trm_ctx *d,
 static void ohci1394_pci_remove(struct pci_dev *pdev);
 
 #ifndef __LITTLE_ENDIAN
-static unsigned hdr_sizes[] =
-{
+const static size_t hdr_sizes[] = {
         3,      /* TCODE_WRITEQ */
         4,      /* TCODE_WRITEB */
         3,      /* TCODE_WRITE_RESPONSE */
-        0,      /* ??? */
+        0,      /* reserved */
         3,      /* TCODE_READQ */
         4,      /* TCODE_READB */
         3,      /* TCODE_READQ_RESPONSE */
         4,      /* TCODE_READB_RESPONSE */
-        1,      /* TCODE_CYCLE_START (???) */
+        1,      /* TCODE_CYCLE_START */
         4,      /* TCODE_LOCK_REQUEST */
         2,      /* TCODE_ISO_DATA */
         4,      /* TCODE_LOCK_RESPONSE */
+                /* rest is reserved or link-internal */
 };
 
-/* Swap headers */
-static inline void packet_swab(quadlet_t *data, int tcode)
+static inline void header_le32_to_cpu(quadlet_t *data, unsigned char tcode)
 {
-        size_t size = hdr_sizes[tcode];
+        size_t size;
 
-        if (tcode > TCODE_LOCK_RESPONSE || hdr_sizes[tcode] == 0)
+        if (unlikely(tcode >= ARRAY_SIZE(hdr_sizes)))
                 return;
 
+        size = hdr_sizes[tcode];
         while (size--)
-                data[size] = swab32(data[size]);
+                data[size] = le32_to_cpu(data[size]);
 }
 #else
-/* Don't waste cycles on same sex byte swaps */
-#define packet_swab(w,x) do {} while (0)
+#define header_le32_to_cpu(w,x) do {} while (0)
 #endif /* !LITTLE_ENDIAN */
 
 /***********************************
@@ -701,7 +700,7 @@ static void insert_packet(struct ti_ohci *ohci,
                                 d->prg_cpu[idx]->data[2] = packet->header[2];
                                 d->prg_cpu[idx]->data[3] = packet->header[3];
                         }
-                        packet_swab(d->prg_cpu[idx]->data, packet->tcode);
+                        header_le32_to_cpu(d->prg_cpu[idx]->data, packet->tcode);
                 }
 
                 if (packet->data_size) { /* block transmit */
@@ -777,7 +776,7 @@ static void insert_packet(struct ti_ohci *ohci,
                 d->prg_cpu[idx]->data[0] = packet->speed_code<<16 |
                         (packet->header[0] & 0xFFFF);
                 d->prg_cpu[idx]->data[1] = packet->header[0] & 0xFFFF0000;
-                packet_swab(d->prg_cpu[idx]->data, packet->tcode);
+                header_le32_to_cpu(d->prg_cpu[idx]->data, packet->tcode);
 
                 d->prg_cpu[idx]->begin.control =
                         cpu_to_le32(DMA_CTL_OUTPUT_MORE |
@@ -2731,7 +2730,7 @@ static void dma_rcv_tasklet (unsigned long data)
                  * bus reset. We always ignore it.  */
                 if (tcode != OHCI1394_TCODE_PHY) {
                         if (!ohci->no_swap_incoming)
-                                packet_swab(d->spb, tcode);
+                                header_le32_to_cpu(d->spb, tcode);
                         DBGMSG("Packet received from node"
                                 " %d ack=0x%02X spd=%d tcode=0x%X"
                                 " length=%d ctx=%d tlabel=%d",