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