/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Memory copy functions for 32-bit PowerPC. * * Copyright (C) 1996-2005 Paul Mackerras. */ #include <linux/export.h> #include <asm/processor.h> #include <asm/cache.h> #include <asm/errno.h> #include <asm/ppc_asm.h> #include <asm/code-patching-asm.h> #include <asm/kasan.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; \ EX_TABLE(8 ## n ## 0b,9 ## n ## 0b); \ EX_TABLE(8 ## n ## 1b,9 ## n ## 0b); \ EX_TABLE(8 ## n ## 2b,9 ## n ## 0b); \ EX_TABLE(8 ## n ## 3b,9 ## n ## 0b); \ EX_TABLE(8 ## n ## 4b,9 ## n ## 1b); \ EX_TABLE(8 ## n ## 5b,9 ## n ## 1b); \ EX_TABLE(8 ## n ## 6b,9 ## n ## 1b); \ EX_TABLE(8 ## n ## 7b,9 ## n ## 1b) .text CACHELINE_BYTES = L1_CACHE_BYTES LG_CACHELINE_BYTES = L1_CACHE_SHIFT CACHELINE_MASK = (L1_CACHE_BYTES-1) #ifndef CONFIG_KASAN _GLOBAL(memset16) rlwinm. r0 ,r5, 31, 1, 31 addi r6, r3, -4 beq- 2f rlwimi r4 ,r4 ,16 ,0 ,15 mtctr r0 1: stwu r4, 4(r6) bdnz 1b 2: andi. r0, r5, 1 beqlr sth r4, 4(r6) blr EXPORT_SYMBOL(memset16) #endif /* * Use dcbz on the complete cache lines in the destination * to set them to zero. This requires that the destination * area is cacheable. -- paulus * * During early init, cache might not be active yet, so dcbz cannot be used. * We therefore skip the optimised bloc that uses dcbz. This jump is * replaced by a nop once cache is active. This is done in machine_init() */ _GLOBAL_KASAN(memset) cmplwi 0,r5,4 blt 7f rlwimi r4,r4,8,16,23 rlwimi r4,r4,16,0,15 stw r4,0(r3) beqlr andi. r0,r3,3 add r5,r0,r5 subf r6,r0,r3 cmplwi 0,r4,0 /* * Skip optimised bloc until cache is enabled. Will be replaced * by 'bne' during boot to use normal procedure if r4 is not zero */ 5: b 2f patch_site 5b, patch__memset_nocache 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 10: dcbz r7,r6 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 beqlr mtctr r5 addi r6,r6,3 8: stbu r4,1(r6) bdnz 8b blr 7: cmpwi 0,r5,0 beqlr mtctr r5 addi r6,r3,-1 9: stbu r4,1(r6) bdnz 9b blr EXPORT_SYMBOL(memset) EXPORT_SYMBOL_KASAN(memset) /* * 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. * * During early init, cache might not be active yet, so dcbz cannot be used. * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is * replaced by a nop once cache is active. This is done in machine_init() */ _GLOBAL_KASAN(memmove) cmplw 0,r3,r4 bgt backwards_memcpy /* fall through */ _GLOBAL_KASAN(memcpy) 1: b generic_memcpy patch_site 1b, patch__memcpy_nocache 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 generic_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 */ addi r4,r4,1 addi r6,r6,1 stb r9,3(r6) 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: dcbz r11,r6 COPY_16_BYTES #if L1_CACHE_BYTES >= 32 COPY_16_BYTES #if L1_CACHE_BYTES >= 64 COPY_16_BYTES COPY_16_BYTES #if L1_CACHE_BYTES >= 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 addi r4,r4,3 addi r6,r6,3 40: lbzu r0,1(r4) stbu r0,1(r6) bdnz 40b 65: blr EXPORT_SYMBOL(memcpy) EXPORT_SYMBOL(memmove) EXPORT_SYMBOL_KASAN(memcpy) EXPORT_SYMBOL_KASAN(memmove) generic_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(__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 EX_TABLE(70b,100f) EX_TABLE(71b,101f) EX_TABLE(72b,102f) EX_TABLE(73b,103f) 58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */ clrlwi r5,r5,32-LG_CACHELINE_BYTES li r11,4 beq 63f /* 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 EX_TABLE(54b,105f) /* the main body of the cacheline loop */ COPY_16_BYTES_WITHEX(0) #if L1_CACHE_BYTES >= 32 COPY_16_BYTES_WITHEX(1) #if L1_CACHE_BYTES >= 64 COPY_16_BYTES_WITHEX(2) COPY_16_BYTES_WITHEX(3) #if L1_CACHE_BYTES >= 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 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_BYTES >= 32 COPY_16_BYTES_EXCODE(1) #if L1_CACHE_BYTES >= 64 COPY_16_BYTES_EXCODE(2) COPY_16_BYTES_EXCODE(3) #if L1_CACHE_BYTES >= 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 mfctr r8 add r0,r0,r8 b 106f /* 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 106: 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 120: blr EX_TABLE(30b,108b) EX_TABLE(31b,109b) EX_TABLE(40b,110b) EX_TABLE(41b,111b) EX_TABLE(130b,132b) EX_TABLE(131b,120b) EXPORT_SYMBOL(__copy_tofrom_user)