| From 3c0be5849259b729580c23549330973a2dd513a2 Mon Sep 17 00:00:00 2001 |
| From: Paul Burton <paul.burton@mips.com> |
| Date: Tue, 8 Oct 2019 19:46:01 +0000 |
| Subject: MIPS: Drop 32-bit asm string functions |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Paul Burton <paul.burton@mips.com> |
| |
| commit 3c0be5849259b729580c23549330973a2dd513a2 upstream. |
| |
| We have assembly implementations of strcpy(), strncpy(), strcmp() & |
| strncmp() which: |
| |
| - Are simple byte-at-a-time loops with no particular optimizations. As |
| a comment in the code describes, they're "rather naive". |
| |
| - Offer no clear performance advantage over the generic C |
| implementations - in microbenchmarks performed by Alexander Lobakin |
| the asm functions sometimes win & sometimes lose, but generally not |
| by large margins in either direction. |
| |
| - Don't support 64-bit kernels, where we already make use of the |
| generic C implementations. |
| |
| - Tend to bloat kernel code size due to inlining. |
| |
| - Don't support CONFIG_FORTIFY_SOURCE. |
| |
| - Won't support nanoMIPS without rework. |
| |
| For all of these reasons, delete the asm implementations & make use of |
| the generic C implementations for 32-bit kernels just like we already do |
| for 64-bit kernels. |
| |
| Signed-off-by: Paul Burton <paul.burton@mips.com> |
| URL: https://lore.kernel.org/linux-mips/a2a35f1cf58d6db19eb4af9b4ae21e35@dlink.ru/ |
| Cc: Alexander Lobakin <alobakin@dlink.ru> |
| Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> |
| Cc: linux-mips@vger.kernel.org |
| Signed-off-by: Florian Westphal <fw@strlen.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/mips/include/asm/string.h | 121 ----------------------------------------- |
| 1 file changed, 121 deletions(-) |
| |
| --- a/arch/mips/include/asm/string.h |
| +++ b/arch/mips/include/asm/string.h |
| @@ -10,127 +10,6 @@ |
| #ifndef _ASM_STRING_H |
| #define _ASM_STRING_H |
| |
| - |
| -/* |
| - * Most of the inline functions are rather naive implementations so I just |
| - * didn't bother updating them for 64-bit ... |
| - */ |
| -#ifdef CONFIG_32BIT |
| - |
| -#ifndef IN_STRING_C |
| - |
| -#define __HAVE_ARCH_STRCPY |
| -static __inline__ char *strcpy(char *__dest, __const__ char *__src) |
| -{ |
| - char *__xdest = __dest; |
| - |
| - __asm__ __volatile__( |
| - ".set\tnoreorder\n\t" |
| - ".set\tnoat\n" |
| - "1:\tlbu\t$1,(%1)\n\t" |
| - "addiu\t%1,1\n\t" |
| - "sb\t$1,(%0)\n\t" |
| - "bnez\t$1,1b\n\t" |
| - "addiu\t%0,1\n\t" |
| - ".set\tat\n\t" |
| - ".set\treorder" |
| - : "=r" (__dest), "=r" (__src) |
| - : "0" (__dest), "1" (__src) |
| - : "memory"); |
| - |
| - return __xdest; |
| -} |
| - |
| -#define __HAVE_ARCH_STRNCPY |
| -static __inline__ char *strncpy(char *__dest, __const__ char *__src, size_t __n) |
| -{ |
| - char *__xdest = __dest; |
| - |
| - if (__n == 0) |
| - return __xdest; |
| - |
| - __asm__ __volatile__( |
| - ".set\tnoreorder\n\t" |
| - ".set\tnoat\n" |
| - "1:\tlbu\t$1,(%1)\n\t" |
| - "subu\t%2,1\n\t" |
| - "sb\t$1,(%0)\n\t" |
| - "beqz\t$1,2f\n\t" |
| - "addiu\t%0,1\n\t" |
| - "bnez\t%2,1b\n\t" |
| - "addiu\t%1,1\n" |
| - "2:\n\t" |
| - ".set\tat\n\t" |
| - ".set\treorder" |
| - : "=r" (__dest), "=r" (__src), "=r" (__n) |
| - : "0" (__dest), "1" (__src), "2" (__n) |
| - : "memory"); |
| - |
| - return __xdest; |
| -} |
| - |
| -#define __HAVE_ARCH_STRCMP |
| -static __inline__ int strcmp(__const__ char *__cs, __const__ char *__ct) |
| -{ |
| - int __res; |
| - |
| - __asm__ __volatile__( |
| - ".set\tnoreorder\n\t" |
| - ".set\tnoat\n\t" |
| - "lbu\t%2,(%0)\n" |
| - "1:\tlbu\t$1,(%1)\n\t" |
| - "addiu\t%0,1\n\t" |
| - "bne\t$1,%2,2f\n\t" |
| - "addiu\t%1,1\n\t" |
| - "bnez\t%2,1b\n\t" |
| - "lbu\t%2,(%0)\n\t" |
| -#if defined(CONFIG_CPU_R3000) |
| - "nop\n\t" |
| -#endif |
| - "move\t%2,$1\n" |
| - "2:\tsubu\t%2,$1\n" |
| - "3:\t.set\tat\n\t" |
| - ".set\treorder" |
| - : "=r" (__cs), "=r" (__ct), "=r" (__res) |
| - : "0" (__cs), "1" (__ct)); |
| - |
| - return __res; |
| -} |
| - |
| -#endif /* !defined(IN_STRING_C) */ |
| - |
| -#define __HAVE_ARCH_STRNCMP |
| -static __inline__ int |
| -strncmp(__const__ char *__cs, __const__ char *__ct, size_t __count) |
| -{ |
| - int __res; |
| - |
| - __asm__ __volatile__( |
| - ".set\tnoreorder\n\t" |
| - ".set\tnoat\n" |
| - "1:\tlbu\t%3,(%0)\n\t" |
| - "beqz\t%2,2f\n\t" |
| - "lbu\t$1,(%1)\n\t" |
| - "subu\t%2,1\n\t" |
| - "bne\t$1,%3,3f\n\t" |
| - "addiu\t%0,1\n\t" |
| - "bnez\t%3,1b\n\t" |
| - "addiu\t%1,1\n" |
| - "2:\n\t" |
| -#if defined(CONFIG_CPU_R3000) |
| - "nop\n\t" |
| -#endif |
| - "move\t%3,$1\n" |
| - "3:\tsubu\t%3,$1\n\t" |
| - ".set\tat\n\t" |
| - ".set\treorder" |
| - : "=r" (__cs), "=r" (__ct), "=r" (__count), "=r" (__res) |
| - : "0" (__cs), "1" (__ct), "2" (__count)); |
| - |
| - return __res; |
| -} |
| -#endif /* CONFIG_32BIT */ |
| - |
| #define __HAVE_ARCH_MEMSET |
| extern void *memset(void *__s, int __c, size_t __count); |
| |
