From: Paul Burton <paul.burton@xxxxxxxx> 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. [ stable note: mips32 strncpy does not pad remaining dest buf which causes nftables iifname compare failures ]. Signed-off-by: Paul Burton <paul.burton@xxxxxxxx> URL: https://lore.kernel.org/linux-mips/a2a35f1cf58d6db19eb4af9b4ae21e35@xxxxxxxx/ Cc: Alexander Lobakin <alobakin@xxxxxxxx> Reviewed-by: Philippe Mathieu-Daudé <f4bug@xxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxxx Signed-off-by: Florian Westphal <fw@xxxxxxxxx> --- arch/mips/include/asm/string.h | 121 --------------------------------- 1 file changed, 121 deletions(-) diff --git a/arch/mips/include/asm/string.h b/arch/mips/include/asm/string.h index 29030cb398ee..1de3bbce8e88 100644 --- 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); -- 2.26.2
