1 /* SPDX-License-Identifier: GPL-2.0 */ 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/linkage.h> 5 #include "sysdep.h" 6 7 .weak memset 8 ENTRY(__memset) 9 ENTRY(memset) 10 /* Test if len less than 4 bytes. */ 11 mov r12, r0 12 cmplti r2, 8 13 bt .L_set_by_byte 14 15 andi r13, r0, 3 16 movi r19, 4 17 /* Test if dest is not 4 bytes aligned. */ 18 bnez r13, .L_dest_not_aligned 19 /* Hardware can handle unaligned access directly. */ 20 .L_dest_aligned: 21 zextb r3, r1 22 lsli r1, 8 23 or r1, r3 24 lsli r3, r1, 16 25 or r3, r1 26 27 /* If dest is aligned, then copy. */ 28 zext r18, r2, 31, 4 29 /* Test if len less than 16 bytes. */ 30 bez r18, .L_len_less_16bytes 31 32 LABLE_ALIGN 33 .L_len_larger_16bytes: 34 stw r3, (r0, 0) 35 stw r3, (r0, 4) 36 stw r3, (r0, 8) 37 stw r3, (r0, 12) 38 PRE_BNEZAD (r18) 39 addi r0, 16 40 BNEZAD (r18, .L_len_larger_16bytes) 41 42 .L_len_less_16bytes: 43 zext r18, r2, 3, 2 44 andi r2, 3 45 bez r18, .L_set_by_byte 46 .L_len_less_16bytes_loop: 47 stw r3, (r0, 0) 48 PRE_BNEZAD (r18) 49 addi r0, 4 50 BNEZAD (r18, .L_len_less_16bytes_loop) 51 52 /* Test if len less than 4 bytes. */ 53 .L_set_by_byte: 54 zext r18, r2, 2, 0 55 bez r18, .L_return 56 .L_set_by_byte_loop: 57 stb r1, (r0, 0) 58 PRE_BNEZAD (r18) 59 addi r0, 1 60 BNEZAD (r18, .L_set_by_byte_loop) 61 62 .L_return: 63 mov r0, r12 64 rts 65 66 /* If dest is not aligned, just set some bytes makes the dest 67 align. */ 68 69 .L_dest_not_aligned: 70 sub r13, r19, r13 71 sub r2, r13 72 .L_dest_not_aligned_loop: 73 /* Makes the dest align. */ 74 stb r1, (r0, 0) 75 PRE_BNEZAD (r13) 76 addi r0, 1 77 BNEZAD (r13, .L_dest_not_aligned_loop) 78 cmplti r2, 8 79 bt .L_set_by_byte 80 /* Check whether the src is aligned. */ 81 jbr .L_dest_aligned 82 ENDPROC(memset) 83 ENDPROC(__memset) 84