diff options
Diffstat (limited to 'arch/ppc/lib/string.S')
| -rw-r--r-- | arch/ppc/lib/string.S | 716 |
1 files changed, 716 insertions, 0 deletions
diff --git a/arch/ppc/lib/string.S b/arch/ppc/lib/string.S new file mode 100644 index 000000000000..8d08a2eb225e --- /dev/null +++ b/arch/ppc/lib/string.S @@ -0,0 +1,716 @@ +/* + * 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/cache.h> +#include <asm/errno.h> +#include <asm/ppc_asm.h> + +#define COPY_16_BYTES \ + lwz r7,4(r4); \ + lwz r8,8(r4); \ + lwz r9,12(r4); \ + lwzu r10,16(r4); \ + stw r7,4(r6); \ + stw r8,8(r6); \ + stw r9,12(r6); \ + stwu r10,16(r6) + +#define COPY_16_BYTES_WITHEX(n) \ +8 ## n ## 0: \ + lwz r7,4(r4); \ +8 ## n ## 1: \ + lwz r8,8(r4); \ +8 ## n ## 2: \ + lwz r9,12(r4); \ +8 ## n ## 3: \ + lwzu r10,16(r4); \ +8 ## n ## 4: \ + stw r7,4(r6); \ +8 ## n ## 5: \ + stw r8,8(r6); \ +8 ## n ## 6: \ + stw r9,12(r6); \ +8 ## n ## 7: \ + stwu r10,16(r6) + +#define COPY_16_BYTES_EXCODE(n) \ +9 ## n ## 0: \ + addi r5,r5,-(16 * n); \ + b 104f; \ +9 ## n ## 1: \ + addi r5,r5,-(16 * n); \ + b 105f; \ +.section __ex_table,"a"; \ + .align 2; \ + .long 8 ## n ## 0b,9 ## n ## 0b; \ + .long 8 ## n ## 1b,9 ## n ## 0b; \ + .long 8 ## n ## 2b,9 ## n ## 0b; \ + .long 8 ## n ## 3b,9 ## n ## 0b; \ + .long 8 ## n ## 4b,9 ## n ## 1b; \ + .long 8 ## n ## 5b,9 ## n ## 1b; \ + .long 8 ## n ## 6b,9 ## n ## 1b; \ + .long 8 ## n ## 7b,9 ## n ## 1b; \ + .text + + .text + .stabs "arch/ppc/lib/",N_SO,0,0,0f + .stabs "string.S",N_SO,0,0,0f + +CACHELINE_BYTES = L1_CACHE_LINE_SIZE +LG_CACHELINE_BYTES = LG_L1_CACHE_LINE_SIZE +CACHELINE_MASK = (L1_CACHE_LINE_SIZE-1) + +_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 + +/* + * Use dcbz on the complete cache lines in the destination + * to set them to zero. This requires that the destination + * area is cacheable. -- paulus + */ +_GLOBAL(cacheable_memzero) + mr r5,r4 + li r4,0 + addi r6,r3,-4 + cmplwi 0,r5,4 + blt 7f + stwu r4,4(r6) + beqlr + andi. r0,r6,3 + add r5,r0,r5 + subf r6,r0,r6 + clrlwi r7,r6,32-LG_CACHELINE_BYTES + add r8,r7,r5 + srwi r9,r8,LG_CACHELINE_BYTES + addic. r9,r9,-1 /* total number of complete cachelines */ + ble 2f + xori r0,r7,CACHELINE_MASK & ~3 + srwi. r0,r0,2 + beq 3f + mtctr r0 +4: stwu r4,4(r6) + bdnz 4b +3: mtctr r9 + li r7,4 +#if !defined(CONFIG_8xx) +10: dcbz r7,r6 +#else +10: stw r4, 4(r6) + stw r4, 8(r6) + stw r4, 12(r6) + stw r4, 16(r6) +#if CACHE_LINE_SIZE >= 32 + stw r4, 20(r6) + stw r4, 24(r6) + stw r4, 28(r6) + stw r4, 32(r6) +#endif /* CACHE_LINE_SIZE */ +#endif + addi r6,r6,CACHELINE_BYTES + bdnz 10b + clrlwi r5,r8,32-LG_CACHELINE_BYTES + addi r5,r5,4 +2: srwi r0,r5,2 + mtctr r0 + bdz 6f +1: stwu r4,4(r6) + bdnz 1b +6: andi. r5,r5,3 +7: cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r6,r6,3 +8: stbu r4,1(r6) + bdnz 8b + blr + +_GLOBAL(memset) + rlwimi r4,r4,8,16,23 + rlwimi r4,r4,16,0,15 + addi r6,r3,-4 + cmplwi 0,r5,4 + blt 7f + stwu r4,4(r6) + beqlr + andi. r0,r6,3 + add r5,r0,r5 + subf r6,r0,r6 + srwi r0,r5,2 + mtctr r0 + bdz 6f +1: stwu r4,4(r6) + bdnz 1b +6: andi. r5,r5,3 +7: cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r6,r6,3 +8: stbu r4,1(r6) + bdnz 8b + blr + +/* + * This version uses dcbz on the complete cache lines in the + * destination area to reduce memory traffic. This requires that + * the destination area is cacheable. + * We only use this version if the source and dest don't overlap. + * -- paulus. + */ +_GLOBAL(cacheable_memcpy) + add r7,r3,r5 /* test if the src & dst overlap */ + add r8,r4,r5 + cmplw 0,r4,r7 + cmplw 1,r3,r8 + crand 0,0,4 /* cr0.lt &= cr1.lt */ + blt memcpy /* if regions overlap */ + + addi r4,r4,-4 + addi r6,r3,-4 + neg r0,r3 + andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */ + beq 58f + + cmplw 0,r5,r0 /* is this more than total to do? */ + blt 63f /* if not much to do */ + andi. r8,r0,3 /* get it word-aligned first */ + subf r5,r0,r5 + mtctr r8 + beq+ 61f +70: lbz r9,4(r4) /* do some bytes */ + stb r9,4(r6) + addi r4,r4,1 + addi r6,r6,1 + bdnz 70b +61: srwi. r0,r0,2 + mtctr r0 + beq 58f +72: lwzu r9,4(r4) /* do some words */ + stwu r9,4(r6) + bdnz 72b + +58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */ + clrlwi r5,r5,32-LG_CACHELINE_BYTES + li r11,4 + mtctr r0 + beq 63f +53: +#if !defined(CONFIG_8xx) + dcbz r11,r6 +#endif + COPY_16_BYTES +#if L1_CACHE_LINE_SIZE >= 32 + COPY_16_BYTES +#if L1_CACHE_LINE_SIZE >= 64 + COPY_16_BYTES + COPY_16_BYTES +#if L1_CACHE_LINE_SIZE >= 128 + COPY_16_BYTES + COPY_16_BYTES + COPY_16_BYTES + COPY_16_BYTES +#endif +#endif +#endif + bdnz 53b + +63: srwi. r0,r5,2 + mtctr r0 + beq 64f +30: lwzu r0,4(r4) + stwu r0,4(r6) + bdnz 30b + +64: andi. r0,r5,3 + mtctr r0 + beq+ 65f +40: lbz r0,4(r4) + stb r0,4(r6) + addi r4,r4,1 + addi r6,r6,1 + bdnz 40b +65: blr + +_GLOBAL(memmove) + cmplw 0,r3,r4 + bgt backwards_memcpy + /* fall through */ + +_GLOBAL(memcpy) + srwi. r7,r5,3 + addi r6,r3,-4 + addi r4,r4,-4 + beq 2f /* if less than 8 bytes to do */ + andi. r0,r6,3 /* get dest word aligned */ + mtctr r7 + bne 5f +1: lwz r7,4(r4) + lwzu r8,8(r4) + stw r7,4(r6) + stwu r8,8(r6) + bdnz 1b + andi. r5,r5,7 +2: cmplwi 0,r5,4 + blt 3f + lwzu r0,4(r4) + addi r5,r5,-4 + stwu r0,4(r6) +3: cmpwi 0,r5,0 + beqlr + mtctr r5 + addi r4,r4,3 + addi r6,r6,3 +4: lbzu r0,1(r4) + stbu r0,1(r6) + bdnz 4b + blr +5: subfic r0,r0,4 + mtctr r0 +6: lbz r7,4(r4) + addi r4,r4,1 + stb r7,4(r6) + addi r6,r6,1 + bdnz 6b + subf r5,r0,r5 + rlwinm. r7,r5,32-3,3,31 + beq 2b + mtctr r7 + b 1b + +_GLOBAL(backwards_memcpy) + rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */ + add r6,r3,r5 + add r4,r4,r5 + beq 2f + andi. r0,r6,3 + mtctr r7 + bne 5f +1: lwz r7,-4(r4) + lwzu r8,-8(r4) + stw r7,-4(r6) + stwu r8,-8(r6) + bdnz 1b + andi. r5,r5,7 +2: cmplwi 0,r5,4 + blt 3f + lwzu r0,-4(r4) + subi r5,r5,4 + stwu r0,-4(r6) +3: cmpwi 0,r5,0 + beqlr + mtctr r5 +4: lbzu r0,-1(r4) + stbu r0,-1(r6) + bdnz 4b + blr +5: mtctr r0 +6: lbzu r7,-1(r4) + stbu r7,-1(r6) + bdnz 6b + subf r5,r0,r5 + rlwinm. r7,r5,32-3,3,31 + beq 2b + mtctr r7 + b 1b + +_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(__copy_tofrom_user) + addi r4,r4,-4 + addi r6,r3,-4 + neg r0,r3 + andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */ + beq 58f + + cmplw 0,r5,r0 /* is this more than total to do? */ + blt 63f /* if not much to do */ + andi. r8,r0,3 /* get it word-aligned first */ + mtctr r8 + beq+ 61f +70: lbz r9,4(r4) /* do some bytes */ +71: stb r9,4(r6) + addi r4,r4,1 + addi r6,r6,1 + bdnz 70b +61: subf r5,r0,r5 + srwi. r0,r0,2 + mtctr r0 + beq 58f +72: lwzu r9,4(r4) /* do some words */ +73: stwu r9,4(r6) + bdnz 72b + + .section __ex_table,"a" + .align 2 + .long 70b,100f + .long 71b,101f + .long 72b,102f + .long 73b,103f + .text + +58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */ + clrlwi r5,r5,32-LG_CACHELINE_BYTES + li r11,4 + beq 63f + +#ifdef CONFIG_8xx + /* Don't use prefetch on 8xx */ + mtctr r0 +53: COPY_16_BYTES_WITHEX(0) + bdnz 53b + +#else /* not CONFIG_8xx */ + /* Here we decide how far ahead to prefetch the source */ + li r3,4 + cmpwi r0,1 + li r7,0 + ble 114f + li r7,1 +#if MAX_COPY_PREFETCH > 1 + /* Heuristically, for large transfers we prefetch + MAX_COPY_PREFETCH cachelines ahead. For small transfers + we prefetch 1 cacheline ahead. */ + cmpwi r0,MAX_COPY_PREFETCH + ble 112f + li r7,MAX_COPY_PREFETCH +112: mtctr r7 +111: dcbt r3,r4 + addi r3,r3,CACHELINE_BYTES + bdnz 111b +#else + dcbt r3,r4 + addi r3,r3,CACHELINE_BYTES +#endif /* MAX_COPY_PREFETCH > 1 */ + +114: subf r8,r7,r0 + mr r0,r7 + mtctr r8 + +53: dcbt r3,r4 +54: dcbz r11,r6 + .section __ex_table,"a" + .align 2 + .long 54b,105f + .text +/* the main body of the cacheline loop */ + COPY_16_BYTES_WITHEX(0) +#if L1_CACHE_LINE_SIZE >= 32 + COPY_16_BYTES_WITHEX(1) +#if L1_CACHE_LINE_SIZE >= 64 + COPY_16_BYTES_WITHEX(2) + COPY_16_BYTES_WITHEX(3) +#if L1_CACHE_LINE_SIZE >= 128 + COPY_16_BYTES_WITHEX(4) + COPY_16_BYTES_WITHEX(5) + COPY_16_BYTES_WITHEX(6) + COPY_16_BYTES_WITHEX(7) +#endif +#endif +#endif + bdnz 53b + cmpwi r0,0 + li r3,4 + li r7,0 + bne 114b +#endif /* CONFIG_8xx */ + +63: srwi. r0,r5,2 + mtctr r0 + beq 64f +30: lwzu r0,4(r4) +31: stwu r0,4(r6) + bdnz 30b + +64: andi. r0,r5,3 + mtctr r0 + beq+ 65f +40: lbz r0,4(r4) +41: stb r0,4(r6) + addi r4,r4,1 + addi r6,r6,1 + bdnz 40b +65: li r3,0 + blr + +/* read fault, initial single-byte copy */ +100: li r9,0 + b 90f +/* write fault, initial single-byte copy */ +101: li r9,1 +90: subf r5,r8,r5 + li r3,0 + b 99f +/* read fault, initial word copy */ +102: li r9,0 + b 91f +/* write fault, initial word copy */ +103: li r9,1 +91: li r3,2 + b 99f + +/* + * this stuff handles faults in the cacheline loop and branches to either + * 104f (if in read part) or 105f (if in write part), after updating r5 + */ + COPY_16_BYTES_EXCODE(0) +#if L1_CACHE_LINE_SIZE >= 32 + COPY_16_BYTES_EXCODE(1) +#if L1_CACHE_LINE_SIZE >= 64 + COPY_16_BYTES_EXCODE(2) + COPY_16_BYTES_EXCODE(3) +#if L1_CACHE_LINE_SIZE >= 128 + COPY_16_BYTES_EXCODE(4) + COPY_16_BYTES_EXCODE(5) + COPY_16_BYTES_EXCODE(6) + COPY_16_BYTES_EXCODE(7) +#endif +#endif +#endif + +/* read fault in cacheline loop */ +104: li r9,0 + b 92f +/* fault on dcbz (effectively a write fault) */ +/* or write fault in cacheline loop */ +105: li r9,1 +92: li r3,LG_CACHELINE_BYTES + b 99f +/* read fault in final word loop */ +108: li r9,0 + b 93f +/* write fault in final word loop */ +109: li r9,1 +93: andi. r5,r5,3 + li r3,2 + b 99f +/* read fault in final byte loop */ +110: li r9,0 + b 94f +/* write fault in final byte loop */ +111: li r9,1 +94: li r5,0 + li r3,0 +/* + * At this stage the number of bytes not copied is + * r5 + (ctr << r3), and r9 is 0 for read or 1 for write. + */ +99: mfctr r0 + slw r3,r0,r3 + add. r3,r3,r5 + beq 120f /* shouldn't happen */ + cmpwi 0,r9,0 + bne 120f +/* for a read fault, first try to continue the copy one byte at a time */ + mtctr r3 +130: lbz r0,4(r4) +131: stb r0,4(r6) + addi r4,r4,1 + addi r6,r6,1 + bdnz 130b +/* then clear out the destination: r3 bytes starting at 4(r6) */ +132: mfctr r3 + srwi. r0,r3,2 + li r9,0 + mtctr r0 + beq 113f +112: stwu r9,4(r6) + bdnz 112b +113: andi. r0,r3,3 + mtctr r0 + beq 120f +114: stb r9,4(r6) + addi r6,r6,1 + bdnz 114b +120: blr + + .section __ex_table,"a" + .align 2 + .long 30b,108b + .long 31b,109b + .long 40b,110b + .long 41b,111b + .long 130b,132b + .long 131b,120b + .long 112b,120b + .long 114b,120b + .text + +_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" + .align 2 + .long 11b,90b + .long 1b,91b + .long 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" + .align 2 + .long 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" + .align 2 + .long 1b,99b |