| 1 | |
| 2 | * Copyright (C) 2011 Tobias Klauser <[email protected]>
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| 3 | * Copyright (C) 2004 Microtronix Datacom Ltd
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| 4 | *
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| 5 | * This file is subject to the terms and conditions of the GNU General Public
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| 6 | * License. See the file "COPYING" in the main directory of this archive
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| 7 | * for more details.
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| 8 |
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| 9 |
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| 10 | #include <linux/types.h>
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| 11 | #include <linux/string.h>
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| 12 |
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| 13 | void *memset(void *s, int c, size_t count)
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| 14 | {
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| 15 | int destptr, charcnt, dwordcnt, fill8reg, wrkrega;
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| 16 |
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| 17 | if (!count)
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| 18 | return s;
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| 19 |
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| 20 | c &= 0xFF;
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| 21 |
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| 22 | if (count <= 8) {
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| 23 | char *xs = (char *) s;
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| 24 |
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| 25 | while (count--)
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| 26 | *xs++ = c;
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| 27 | return s;
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| 28 | }
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| 29 |
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| 30 | __asm__ __volatile__ (
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| 31 |
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| 32 | " slli %4, %5, 8\n"
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| 33 | " or %4, %4, %5\n"
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| 34 | " slli %3, %4, 16\n"
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| 35 | " or %3, %3, %4\n"
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| 36 |
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| 37 | " andi %4, %0, 0x01\n"
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| 38 | " beq %4, zero, 1f\n"
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| 39 | " addi %1, %1, -1\n"
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| 40 | " stb %3, 0(%0)\n"
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| 41 | " addi %0, %0, 1\n"
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| 42 | "1: mov %2, %1\n"
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| 43 |
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| 44 | " andi %4, %0, 0x02\n"
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| 45 | " beq %4, zero, 2f\n"
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| 46 | " addi %1, %1, -2\n"
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| 47 | " sth %3, 0(%0)\n"
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| 48 | " addi %0, %0, 2\n"
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| 49 | " mov %2, %1\n"
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| 50 |
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| 51 | "2: srli %2, %2, 2\n"
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| 52 |
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| 53 | "3: stw %3, 0(%0)\n"
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| 54 | " addi %0, %0, 4\n"
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| 55 | " addi %2, %2, -1\n"
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| 56 | " bne %2, zero, 3b\n"
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| 57 |
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| 58 | " andi %4, %1, 0x02\n"
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| 59 | " beq %4, zero, 4f\n"
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| 60 | " sth %3, 0(%0)\n"
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| 61 | " addi %0, %0, 2\n"
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| 62 |
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| 63 | "4: andi %4, %1, 0x01\n"
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| 64 | " beq %4, zero, 5f\n"
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| 65 | " stb %3, 0(%0)\n"
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| 66 | "5:\n"
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| 67 | : "=r" (destptr),
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| 68 | "=r" (charcnt),
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| 69 | "=r" (dwordcnt),
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| 70 | "=r" (fill8reg),
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| 71 | "=&r" (wrkrega)
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| 72 | : "r" (c),
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| 73 | "0" (s),
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| 74 | "1" (count)
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| 75 | : "memory"
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| 76 | );
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| 77 |
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| 78 | return s;
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| 79 | }
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