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fpga-manager: altera-ps-spi: use bitrev8x4

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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@gmail.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Joshua Clayton 2017-06-14 10:36:32 -05:00 committed by Greg Kroah-Hartman
parent 3b88da4aba
commit fcfe18f885
1 changed files with 15 additions and 4 deletions
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19
drivers/fpga/altera-ps-spi.c
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@ -149,12 +149,23 @@ static int altera_ps_write_init(struct fpga_manager *mgr,
static void rev_buf(char *buf, size_t len) 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 */ /* set buffer to lsb first */
while (buf < fw_end) { while (fw32 < fw_end) {
*buf = bitrev8(*buf); *fw32 = bitrev8x4(*fw32);
buf++; fw32++;
}
if (extra_bytes) {
buf = (char *)fw_end;
while (extra_bytes) {
*buf = bitrev8(*buf);
buf++;
extra_bytes--;
}
} }
} }