1/* 2 * Copyright (C) 2013 Regents of the University of California 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14#include <linux/linkage.h> 15#include <asm/asm.h> 16 17/* void *memcpy(void *, const void *, size_t) */ 18ENTRY(memcpy) 19 move t6, a0 /* Preserve return value */ 20 21 /* Defer to byte-oriented copy for small sizes */ 22 sltiu a3, a2, 128 23 bnez a3, 4f 24 /* Use word-oriented copy only if low-order bits match */ 25 andi a3, t6, SZREG-1 26 andi a4, a1, SZREG-1 27 bne a3, a4, 4f 28 29 beqz a3, 2f /* Skip if already aligned */ 30 /* 31 * Round to nearest double word-aligned address 32 * greater than or equal to start address 33 */ 34 andi a3, a1, ~(SZREG-1) 35 addi a3, a3, SZREG 36 /* Handle initial misalignment */ 37 sub a4, a3, a1 381: 39 lb a5, 0(a1) 40 addi a1, a1, 1 41 sb a5, 0(t6) 42 addi t6, t6, 1 43 bltu a1, a3, 1b 44 sub a2, a2, a4 /* Update count */ 45 462: 47 andi a4, a2, ~((16*SZREG)-1) 48 beqz a4, 4f 49 add a3, a1, a4 503: 51 REG_L a4, 0(a1) 52 REG_L a5, SZREG(a1) 53 REG_L a6, 2*SZREG(a1) 54 REG_L a7, 3*SZREG(a1) 55 REG_L t0, 4*SZREG(a1) 56 REG_L t1, 5*SZREG(a1) 57 REG_L t2, 6*SZREG(a1) 58 REG_L t3, 7*SZREG(a1) 59 REG_L t4, 8*SZREG(a1) 60 REG_L t5, 9*SZREG(a1) 61 REG_S a4, 0(t6) 62 REG_S a5, SZREG(t6) 63 REG_S a6, 2*SZREG(t6) 64 REG_S a7, 3*SZREG(t6) 65 REG_S t0, 4*SZREG(t6) 66 REG_S t1, 5*SZREG(t6) 67 REG_S t2, 6*SZREG(t6) 68 REG_S t3, 7*SZREG(t6) 69 REG_S t4, 8*SZREG(t6) 70 REG_S t5, 9*SZREG(t6) 71 REG_L a4, 10*SZREG(a1) 72 REG_L a5, 11*SZREG(a1) 73 REG_L a6, 12*SZREG(a1) 74 REG_L a7, 13*SZREG(a1) 75 REG_L t0, 14*SZREG(a1) 76 REG_L t1, 15*SZREG(a1) 77 addi a1, a1, 16*SZREG 78 REG_S a4, 10*SZREG(t6) 79 REG_S a5, 11*SZREG(t6) 80 REG_S a6, 12*SZREG(t6) 81 REG_S a7, 13*SZREG(t6) 82 REG_S t0, 14*SZREG(t6) 83 REG_S t1, 15*SZREG(t6) 84 addi t6, t6, 16*SZREG 85 bltu a1, a3, 3b 86 andi a2, a2, (16*SZREG)-1 /* Update count */ 87 884: 89 /* Handle trailing misalignment */ 90 beqz a2, 6f 91 add a3, a1, a2 92 93 /* Use word-oriented copy if co-aligned to word boundary */ 94 or a5, a1, t6 95 or a5, a5, a3 96 andi a5, a5, 3 97 bnez a5, 5f 987: 99 lw a4, 0(a1) 100 addi a1, a1, 4 101 sw a4, 0(t6) 102 addi t6, t6, 4 103 bltu a1, a3, 7b 104 105 ret 106 1075: 108 lb a4, 0(a1) 109 addi a1, a1, 1 110 sb a4, 0(t6) 111 addi t6, t6, 1 112 bltu a1, a3, 5b 1136: 114 ret 115END(memcpy) 116