From: Alan Tull <atull@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Moritz Fischer <moritz.fischer@ettus.com>,
Alan Tull <atull@kernel.org>,
linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org,
Joshua Clayton <stillcompiling@gmail.com>
Subject: [PATCH v2 07/11] lib: add bitrev8x4()
Date: Wed, 14 Jun 2017 10:36:31 -0500 [thread overview]
Message-ID: <20170614153635.2763-8-atull@kernel.org> (raw)
In-Reply-To: <20170614153635.2763-1-atull@kernel.org>
From: Joshua Clayton <stillcompiling@gmail.com>
Add a function to reverse bytes within a 32 bit word.
Operate on a u32 rather than individual bytes.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Alan Tull <atull@kernel.org>
---
include/linux/bitrev.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h
index fb790b8..b97be27 100644
--- a/include/linux/bitrev.h
+++ b/include/linux/bitrev.h
@@ -29,6 +29,8 @@ static inline u32 __bitrev32(u32 x)
#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
+#define __bitrev8x4(x) (__bitrev32(swab32(x)))
+
#define __constant_bitrev32(x) \
({ \
u32 __x = x; \
@@ -50,6 +52,15 @@ static inline u32 __bitrev32(u32 x)
__x; \
})
+#define __constant_bitrev8x4(x) \
+({ \
+ u32 __x = x; \
+ __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \
+ __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \
+ __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \
+ __x; \
+})
+
#define __constant_bitrev8(x) \
({ \
u8 __x = x; \
@@ -75,6 +86,14 @@ static inline u32 __bitrev32(u32 x)
__bitrev16(__x); \
})
+#define bitrev8x4(x) \
+({ \
+ u32 __x = x; \
+ __builtin_constant_p(__x) ? \
+ __constant_bitrev8x4(__x) : \
+ __bitrev8x4(__x); \
+ })
+
#define bitrev8(x) \
({ \
u8 __x = x; \
--
2.7.4
next prev parent reply other threads:[~2017-06-14 15:36 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-14 15:36 [PATCH v2 00/11] patches for fpga Alan Tull
2017-06-14 15:36 ` [PATCH v2 01/11] dt-bindings: fpga: Add bindings document for Xilinx LogiCore PR Decoupler Alan Tull
2017-06-14 15:36 ` [PATCH v2 02/11] Make FPGA a menuconfig to ease disabling it all Alan Tull
2017-06-14 15:36 ` [PATCH v2 03/11] fpga: Add flag to indicate SPI bitstream is bit-reversed Alan Tull
2017-06-14 15:36 ` [PATCH v2 04/11] doc: dt: document altera-passive-serial binding Alan Tull
2017-06-14 15:36 ` [PATCH v2 05/11] fpga manager: Add altera-ps-spi driver for Altera FPGAs Alan Tull
2017-06-14 15:36 ` [PATCH v2 06/11] ARM: dts: imx6q-evi: support altera-ps-spi Alan Tull
2017-06-14 15:36 ` Alan Tull [this message]
2017-06-14 15:36 ` [PATCH v2 08/11] fpga-manager: altera-ps-spi: use bitrev8x4 Alan Tull
2017-06-14 15:36 ` [PATCH v2 09/11] of: Add vendor prefix for Lattice Semiconductor Alan Tull
2017-06-14 15:36 ` [PATCH v2 10/11] fpga: Add flag to indicate bitstream needs decompression Alan Tull
2017-06-14 15:36 ` [PATCH v2 11/11] fpga manager: Add Altera CvP driver Alan Tull
2017-07-04 9:03 ` [PATCH v2 00/11] patches for fpga Anatolij Gustschin
2017-07-04 9:12 ` Greg Kroah-Hartman
2017-07-04 9:30 ` Anatolij Gustschin
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