1/* 2 * String handling functions. 3 * 4 * Copyright IBM Corp. 2012 5 */ 6 7#include <linux/linkage.h> 8#include <asm/export.h> 9 10/* 11 * void *memmove(void *dest, const void *src, size_t n) 12 */ 13ENTRY(memmove) 14 ltgr %r4,%r4 15 lgr %r1,%r2 16 bzr %r14 17 clgr %r2,%r3 18 jnh .Lmemmove_forward 19 la %r5,0(%r4,%r3) 20 clgr %r2,%r5 21 jl .Lmemmove_reverse 22.Lmemmove_forward: 23 aghi %r4,-1 24 srlg %r0,%r4,8 25 ltgr %r0,%r0 26 jz .Lmemmove_rest 27.Lmemmove_loop: 28 mvc 0(256,%r1),0(%r3) 29 la %r1,256(%r1) 30 la %r3,256(%r3) 31 brctg %r0,.Lmemmove_loop 32.Lmemmove_rest: 33 larl %r5,.Lmemmove_mvc 34 ex %r4,0(%r5) 35 br %r14 36.Lmemmove_reverse: 37 aghi %r4,-1 38.Lmemmove_reverse_loop: 39 ic %r0,0(%r4,%r3) 40 stc %r0,0(%r4,%r1) 41 brctg %r4,.Lmemmove_reverse_loop 42 ic %r0,0(%r4,%r3) 43 stc %r0,0(%r4,%r1) 44 br %r14 45.Lmemmove_mvc: 46 mvc 0(1,%r1),0(%r3) 47EXPORT_SYMBOL(memmove) 48 49/* 50 * memset implementation 51 * 52 * This code corresponds to the C construct below. We do distinguish 53 * between clearing (c == 0) and setting a memory array (c != 0) simply 54 * because nearly all memset invocations in the kernel clear memory and 55 * the xc instruction is preferred in such cases. 56 * 57 * void *memset(void *s, int c, size_t n) 58 * { 59 * if (likely(c == 0)) 60 * return __builtin_memset(s, 0, n); 61 * return __builtin_memset(s, c, n); 62 * } 63 */ 64ENTRY(memset) 65 ltgr %r4,%r4 66 bzr %r14 67 ltgr %r3,%r3 68 jnz .Lmemset_fill 69 aghi %r4,-1 70 srlg %r3,%r4,8 71 ltgr %r3,%r3 72 lgr %r1,%r2 73 jz .Lmemset_clear_rest 74.Lmemset_clear_loop: 75 xc 0(256,%r1),0(%r1) 76 la %r1,256(%r1) 77 brctg %r3,.Lmemset_clear_loop 78.Lmemset_clear_rest: 79 larl %r3,.Lmemset_xc 80 ex %r4,0(%r3) 81 br %r14 82.Lmemset_fill: 83 stc %r3,0(%r2) 84 cghi %r4,1 85 lgr %r1,%r2 86 ber %r14 87 aghi %r4,-2 88 srlg %r3,%r4,8 89 ltgr %r3,%r3 90 jz .Lmemset_fill_rest 91.Lmemset_fill_loop: 92 mvc 1(256,%r1),0(%r1) 93 la %r1,256(%r1) 94 brctg %r3,.Lmemset_fill_loop 95.Lmemset_fill_rest: 96 larl %r3,.Lmemset_mvc 97 ex %r4,0(%r3) 98 br %r14 99.Lmemset_xc: 100 xc 0(1,%r1),0(%r1) 101.Lmemset_mvc: 102 mvc 1(1,%r1),0(%r1) 103EXPORT_SYMBOL(memset) 104 105/* 106 * memcpy implementation 107 * 108 * void *memcpy(void *dest, const void *src, size_t n) 109 */ 110ENTRY(memcpy) 111 ltgr %r4,%r4 112 bzr %r14 113 aghi %r4,-1 114 srlg %r5,%r4,8 115 ltgr %r5,%r5 116 lgr %r1,%r2 117 jnz .Lmemcpy_loop 118.Lmemcpy_rest: 119 larl %r5,.Lmemcpy_mvc 120 ex %r4,0(%r5) 121 br %r14 122.Lmemcpy_loop: 123 mvc 0(256,%r1),0(%r3) 124 la %r1,256(%r1) 125 la %r3,256(%r3) 126 brctg %r5,.Lmemcpy_loop 127 j .Lmemcpy_rest 128.Lmemcpy_mvc: 129 mvc 0(1,%r1),0(%r3) 130EXPORT_SYMBOL(memcpy) 131