diff options
Diffstat (limited to 'arch/powerpc/lib/string.S')
| -rw-r--r-- | arch/powerpc/lib/string.S | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S new file mode 100644 index 000000000000..b9ca84ed8927 --- /dev/null +++ b/arch/powerpc/lib/string.S @@ -0,0 +1,198 @@ +/* + * String handling functions for PowerPC. + * + * Copyright (C) 1996 Paul Mackerras. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/config.h> +#include <asm/processor.h> +#include <asm/errno.h> +#include <asm/ppc_asm.h> + + .section __ex_table,"a" +#ifdef CONFIG_PPC64 + .align 3 +#define EXTBL .llong +#else + .align 2 +#define EXTBL .long +#endif + .text + +_GLOBAL(strcpy) + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r5) + bne 1b + blr + +/* This clears out any unused part of the destination buffer, + just as the libc version does. -- paulus */ +_GLOBAL(strncpy) + cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r6,r3,-1 + addi r4,r4,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r6) + bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ + bnelr /* if we didn't hit a null char, we're done */ + mfctr r5 + cmpwi 0,r5,0 /* any space left in destination buffer? */ + beqlr /* we know r0 == 0 here */ +2: stbu r0,1(r6) /* clear it out if so */ + bdnz 2b + blr + +_GLOBAL(strcat) + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r0,1(r5) + cmpwi 0,r0,0 + bne 1b + addi r5,r5,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r5) + bne 1b + blr + +_GLOBAL(strcmp) + addi r5,r3,-1 + addi r4,r4,-1 +1: lbzu r3,1(r5) + cmpwi 1,r3,0 + lbzu r0,1(r4) + subf. r3,r0,r3 + beqlr 1 + beq 1b + blr + +_GLOBAL(strlen) + addi r4,r3,-1 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + bne 1b + subf r3,r3,r4 + blr + +_GLOBAL(memcmp) + cmpwi 0,r5,0 + ble- 2f + mtctr r5 + addi r6,r3,-1 + addi r4,r4,-1 +1: lbzu r3,1(r6) + lbzu r0,1(r4) + subf. r3,r0,r3 + bdnzt 2,1b + blr +2: li r3,0 + blr + +_GLOBAL(memchr) + cmpwi 0,r5,0 + ble- 2f + mtctr r5 + addi r3,r3,-1 +1: lbzu r0,1(r3) + cmpw 0,r0,r4 + bdnzf 2,1b + beqlr +2: li r3,0 + blr + +_GLOBAL(__clear_user) + addi r6,r3,-4 + li r3,0 + li r5,0 + cmplwi 0,r4,4 + blt 7f + /* clear a single word */ +11: stwu r5,4(r6) + beqlr + /* clear word sized chunks */ + andi. r0,r6,3 + add r4,r0,r4 + subf r6,r0,r6 + srwi r0,r4,2 + andi. r4,r4,3 + mtctr r0 + bdz 7f +1: stwu r5,4(r6) + bdnz 1b + /* clear byte sized chunks */ +7: cmpwi 0,r4,0 + beqlr + mtctr r4 + addi r6,r6,3 +8: stbu r5,1(r6) + bdnz 8b + blr +90: mr r3,r4 + blr +91: mfctr r3 + slwi r3,r3,2 + add r3,r3,r4 + blr +92: mfctr r3 + blr + + .section __ex_table,"a" + EXTBL 11b,90b + EXTBL 1b,91b + EXTBL 8b,92b + .text + +_GLOBAL(__strncpy_from_user) + addi r6,r3,-1 + addi r4,r4,-1 + cmpwi 0,r5,0 + beq 2f + mtctr r5 +1: lbzu r0,1(r4) + cmpwi 0,r0,0 + stbu r0,1(r6) + bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ + beq 3f +2: addi r6,r6,1 +3: subf r3,r3,r6 + blr +99: li r3,-EFAULT + blr + + .section __ex_table,"a" + EXTBL 1b,99b + .text + +/* r3 = str, r4 = len (> 0), r5 = top (highest addr) */ +_GLOBAL(__strnlen_user) + addi r7,r3,-1 + subf r6,r7,r5 /* top+1 - str */ + cmplw 0,r4,r6 + bge 0f + mr r6,r4 +0: mtctr r6 /* ctr = min(len, top - str) */ +1: lbzu r0,1(r7) /* get next byte */ + cmpwi 0,r0,0 + bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */ + addi r7,r7,1 + subf r3,r3,r7 /* number of bytes we have looked at */ + beqlr /* return if we found a 0 byte */ + cmpw 0,r3,r4 /* did we look at all len bytes? */ + blt 99f /* if not, must have hit top */ + addi r3,r4,1 /* return len + 1 to indicate no null found */ + blr +99: li r3,0 /* bad address, return 0 */ + blr + + .section __ex_table,"a" + EXTBL 1b,99b |