Speed up bit reversal by using hardware bit reversal
Add extra code to handle less than 4byte remnants, if any
Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx>
---
drivers/fpga/altera-ps-spi.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 0db8def668ed..14f14efdf0d5 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -149,12 +149,23 @@ static int altera_ps_write_init(struct fpga_manager *mgr,
static void rev_buf(char *buf, size_t len)
{
- const char *fw_end = (buf + len);
+ u32 *fw32 = (u32 *)buf;
+ size_t extra_bytes = (len & 0x03);
+ const u32 *fw_end = (u32 *)(buf + len - extra_bytes);
/* set buffer to lsb first */
- while (buf < fw_end) {
- *buf = bitrev8(*buf);
- buf++;
+ while (fw32 < fw_end) {
+ *fw32 = bitrev8x4(*fw32);
+ fw32++;
+ }
+
+ if (extra_bytes) {
+ buf = (char *)fw_end;
+ while (extra_bytes) {
+ *buf = bitrev8(*buf);
+ buf++;
+ extra_bytes--;
+ }
}
}
--
2.11.0
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