From mboxrd@z Thu Jan 1 00:00:00 1970 From: Akinobu Mita Subject: [PATCH 1/2] bitops: use find_first_zero_bit() instead of find_next_zero_bit(addr, size, 0) Date: Sat, 27 Nov 2010 01:28:38 +0900 Message-ID: <1290788919-5057-2-git-send-email-akinobu.mita@gmail.com> References: <1290788919-5057-1-git-send-email-akinobu.mita@gmail.com> Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:44932 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755238Ab0KZQ2d (ORCPT ); Fri, 26 Nov 2010 11:28:33 -0500 In-Reply-To: <1290788919-5057-1-git-send-email-akinobu.mita@gmail.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Andrew Morton Cc: Akinobu Mita , Arnd Bergmann The little-endian bitops patch series introduced inefficiency to some little-endian architectures. include/asm-generic/bitops/le.h defines find_first_zero_le_bit() like this: #define find_first_zero_le_bit(addr, size) \ find_next_zero_le_bit((addr), (size), 0) All little-endian architectures include le.h and little-endian bitops are just aliases for their native endian bitops. So above macro definision is converted to: #define find_first_zero_le_bit(addr, size) \ find_next_zero_bit(addr, size, 0) This is inefficient for some architectures which have faster find_first_zero_bit() than find_next_zero_bit(addr, size, 0). Fix it by aliasing find_first_zero_bit() to find_first_zero_le_bit() on little-endian architectures. Signed-off-by: Akinobu Mita Cc: Arnd Bergmann --- include/asm-generic/bitops/le.h | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h index 6ad46ce..17a7119 100644 --- a/include/asm-generic/bitops/le.h +++ b/include/asm-generic/bitops/le.h @@ -12,6 +12,8 @@ find_next_zero_bit(addr, size, offset) #define find_next_le_bit(addr, size, offset) \ find_next_bit(addr, size, offset) +#define find_first_zero_le_bit(addr, size) \ + find_first_zero_bit(addr, size) #elif defined(__BIG_ENDIAN) @@ -22,6 +24,9 @@ extern unsigned long find_next_zero_le_bit(const unsigned long *addr, extern unsigned long find_next_le_bit(const unsigned long *addr, unsigned long size, unsigned long offset); +#define find_first_zero_le_bit(addr, size) \ + find_next_zero_le_bit((addr), (size), 0) + #else #error "Please fix " #endif @@ -43,7 +48,4 @@ extern unsigned long find_next_le_bit(const unsigned long *addr, #define __test_and_clear_le_bit(nr, addr) \ __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) -#define find_first_zero_le_bit(addr, size) \ - find_next_zero_le_bit((addr), (size), 0) - #endif /* _ASM_GENERIC_BITOPS_LE_H_ */ -- 1.7.3.2