From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com (mail-ig0-f169.google.com [209.85.213.169]) by kanga.kvack.org (Postfix) with ESMTP id EE8FC6B006C for ; Mon, 27 Oct 2014 02:46:14 -0400 (EDT) Received: by mail-ig0-f169.google.com with SMTP id uq10so5347922igb.0 for ; Sun, 26 Oct 2014 23:46:14 -0700 (PDT) Received: from smtprelay.hostedemail.com (smtprelay0021.hostedemail.com. [216.40.44.21]) by mx.google.com with ESMTP id zc3si15571006icb.50.2014.10.26.23.46.14 for ; Sun, 26 Oct 2014 23:46:14 -0700 (PDT) Message-ID: <1414392371.8884.2.camel@perches.com> Subject: Re: [RFC V2] arm/arm64:add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction From: Joe Perches Date: Sun, 26 Oct 2014 23:46:11 -0700 In-Reply-To: <35FD53F367049845BC99AC72306C23D103E010D18257@CNBJMBX05.corpusers.net> References: <35FD53F367049845BC99AC72306C23D103E010D18254@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18257@CNBJMBX05.corpusers.net> Content-Type: text/plain; charset="ISO-8859-1" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Wang, Yalin" Cc: 'Russell King - ARM Linux' , "'linux-mm@kvack.org'" , 'Will Deacon' , "'linux-kernel@vger.kernel.org'" , "'linux-arm-kernel@lists.infradead.org'" , "'akinobu.mita@gmail.com'" On Mon, 2014-10-27 at 14:37 +0800, Wang, Yalin wrote: > this change add CONFIG_HAVE_ARCH_BITREVERSE config option, > so that we can use arm/arm64 rbit instruction to do bitrev operation > by hardware. > > Signed-off-by: Yalin Wang > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/bitrev.h | 21 +++++++++++++++++++++ > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/bitrev.h | 21 +++++++++++++++++++++ > include/linux/bitrev.h | 9 +++++++++ > lib/Kconfig | 9 +++++++++ > lib/bitrev.c | 2 ++ > 7 files changed, 64 insertions(+) > create mode 100644 arch/arm/include/asm/bitrev.h > create mode 100644 arch/arm64/include/asm/bitrev.h > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 89c4b5c..426cbcc 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -16,6 +16,7 @@ config ARM > select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS > select GENERIC_ALLOCATOR > select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) > + select HAVE_ARCH_BITREVERSE if (CPU_V7M || CPU_V7) > select GENERIC_CLOCKEVENTS_BROADCAST if SMP > select GENERIC_IDLE_POLL_SETUP > select GENERIC_IRQ_PROBE > diff --git a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h > new file mode 100644 > index 0000000..0df5866 > --- /dev/null > +++ b/arch/arm/include/asm/bitrev.h > @@ -0,0 +1,21 @@ > +#ifndef __ASM_ARM_BITREV_H > +#define __ASM_ARM_BITREV_H > + > +static inline __attribute_const__ u32 __arch_bitrev32(u32 x) > +{ > + __asm__ ("rbit %0, %1" : "=r" (x) : "r" (x)); > + return x; > +} > + > +static inline __attribute_const__ u16 __arch_bitrev16(u16 x) > +{ > + return __arch_bitrev32((u32)x) >> 16; > +} > + > +static inline __attribute_const__ u8 __arch_bitrev8(u8 x) > +{ > + return __arch_bitrev32((u32)x) >> 24; > +} > + > +#endif > + > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 9532f8d..263c28c 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -36,6 +36,7 @@ config ARM64 > select HARDIRQS_SW_RESEND > select HAVE_ARCH_AUDITSYSCALL > select HAVE_ARCH_JUMP_LABEL > + select HAVE_ARCH_BITREVERSE > select HAVE_ARCH_KGDB > select HAVE_ARCH_TRACEHOOK > select HAVE_BPF_JIT > diff --git a/arch/arm64/include/asm/bitrev.h b/arch/arm64/include/asm/bitrev.h > new file mode 100644 > index 0000000..5d24c11 > --- /dev/null > +++ b/arch/arm64/include/asm/bitrev.h > @@ -0,0 +1,21 @@ > +#ifndef __ASM_ARM_BITREV_H > +#define __ASM_ARM_BITREV_H > + > +static inline __attribute_const__ u32 __arch_bitrev32(u32 x) > +{ > + __asm__ ("rbit %w0, %w1" : "=r" (x) : "r" (x)); > + return x; > +} > + > +static inline __attribute_const__ u16 __arch_bitrev16(u16 x) > +{ > + return __arch_bitrev32((u32)x) >> 16; > +} > + > +static inline __attribute_const__ u8 __arch_bitrev8(u8 x) > +{ > + return __arch_bitrev32((u32)x) >> 24; > +} > + > +#endif > + > diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h > index 7ffe03f..ef5b2bb 100644 > --- a/include/linux/bitrev.h > +++ b/include/linux/bitrev.h > @@ -3,6 +3,14 @@ > > #include > > +#ifdef CONFIG_HAVE_ARCH_BITREVERSE > +#include > + > +#define bitrev32 __arch_bitrev32 > +#define bitrev16 __arch_bitrev16 > +#define bitrev8 __arch_bitrev8 > + > +#else > extern u8 const byte_rev_table[256]; If this is done, the direct uses of byte_rev_table in drivers/net/wireless/ath/carl9170/phy.c and sound/usb/6fire/firmware.c should be converted too? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org