| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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) |