From fcfe18f885f6a2a7e906546fe709fccfda73a4b1 Mon Sep 17 00:00:00 2001 From: Joshua Clayton Date: Wed, 14 Jun 2017 10:36:32 -0500 Subject: fpga-manager: altera-ps-spi: use bitrev8x4 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 Signed-off-by: Alan Tull Signed-off-by: Greg Kroah-Hartman --- drivers/fpga/altera-ps-spi.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/fpga') 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--; + } } } -- cgit v1.2.3