Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751382AbdFBUb2 (ORCPT ); Fri, 2 Jun 2017 16:31:28 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:36160 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751326AbdFBUbY (ORCPT ); Fri, 2 Jun 2017 16:31:24 -0400 From: Joshua Clayton To: Alan Tull , Moritz Fischer , Anatolij Gustschin , Bastian Stender , Shawn Guo , Joshua Clayton Cc: Rob Herring , Mark Rutland , Sascha Hauer , Fabio Estevam , Russell King , linux-fpga@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v12 5/6] lib: add bitrev8x4() Date: Fri, 2 Jun 2017 13:30:51 -0700 Message-Id: <7108de698ffdeaa3c61a23997bc0877120bf114e.1496434383.git.stillcompiling@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <684ea151ba9aa2c6555a299daf56552ddc11f596.1496434383.git.stillcompiling@gmail.com> References: <684ea151ba9aa2c6555a299daf56552ddc11f596.1496434383.git.stillcompiling@gmail.com> In-Reply-To: <20170525172911.11467-1-stillcompiling@gmail.com> References: <20170525172911.11467-1-stillcompiling@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1366 Lines: 54 Add a function to reverse bytes within a 32 bit word. Operate on a u32 rather than individual bytes. Signed-off-by: Joshua Clayton --- include/linux/bitrev.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h index fb790b8449c1..b97be27e5a85 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; \ -- 2.11.0