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From: Alan Tull <atull@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org,
	Moritz Fischer <moritz.fischer@ettus.com>,
	delicious.quinoa@gmail.com,
	Joshua Clayton <stillcompiling@gmail.com>,
	Alan Tull <atull@kernel.org>
Subject: [PATCH 09/10] fpga-manager: altera-ps-spi: use bitrev8x4
Date: Mon,  5 Jun 2017 14:07:40 -0500	[thread overview]
Message-ID: <20170605190741.10508-10-atull@kernel.org> (raw)
In-Reply-To: <20170605190741.10508-1-atull@kernel.org>

From: Joshua Clayton <stillcompiling@gmail.com>

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>
---
 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

  parent reply	other threads:[~2017-06-05 19:07 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-05 19:07 [PATCH 00/10] patches for fpga Alan Tull
2017-06-05 19:07 ` [PATCH 01/10] dt-bindings: fpga: Add bindings document for Xilinx LogiCore PR Decoupler Alan Tull
2017-06-05 19:07 ` [PATCH 02/10] Make FPGA a menuconfig to ease disabling it all Alan Tull
2017-06-05 19:07 ` [PATCH 03/10] fpga: allow to compile-test Altera FPGA bridge drivers Alan Tull
2017-06-06 13:45   ` kbuild test robot
2017-06-09  9:49   ` Greg Kroah-Hartman
2017-06-09 13:44     ` Tobias Klauser
2017-06-10  3:55       ` Alan Tull
2017-06-05 19:07 ` [PATCH 04/10] fpga: Add flag to indicate SPI bitstream is bit-reversed Alan Tull
2017-06-05 19:07 ` [PATCH 05/10] doc: dt: document altera-passive-serial binding Alan Tull
2017-06-05 19:07 ` [PATCH 06/10] fpga manager: Add altera-ps-spi driver for Altera FPGAs Alan Tull
2017-06-09  9:51   ` Greg Kroah-Hartman
2017-06-09 13:18     ` Anatolij Gustschin
2017-06-09 22:07       ` stillcompiling
2017-06-10 14:43     ` Alan Tull
2017-06-05 19:07 ` [PATCH 07/10] ARM: dts: imx6q-evi: support altera-ps-spi Alan Tull
2017-06-05 19:07 ` [PATCH 08/10] lib: add bitrev8x4() Alan Tull
2017-06-05 19:07 ` Alan Tull [this message]
2017-06-05 19:07 ` [PATCH 10/10] of: Add vendor prefix for Lattice Semiconductor Alan Tull

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