| 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
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| 2 | /* |
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| 3 | * Copyright (C) 2012 ARM Ltd. |
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| 4 | */ |
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| 5 | |
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| 6 | #include <linux/linkage.h> |
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| 7 | |
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| 8 | #include <asm/asm-uaccess.h> |
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| 9 | #include <asm/assembler.h> |
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| 10 | #include <asm/cache.h> |
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| 11 | |
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| 12 | /* |
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| 13 | * Copy from user space to a kernel buffer (alignment handled by the hardware) |
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| 14 | * |
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| 15 | * Parameters: |
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| 16 | * x0 - to |
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| 17 | * x1 - from |
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| 18 | * x2 - n |
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| 19 | * Returns: |
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| 20 | * x0 - bytes not copied |
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| 21 | */ |
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| 22 | |
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| 23 | .macro ldrb1 reg, ptr, val |
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| 24 | user_ldst 9998f, ldtrb, \reg, \ptr, \val |
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| 25 | .endm |
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| 26 | |
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| 27 | .macro strb1 reg, ptr, val |
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| 28 | strb \reg, [\ptr], \val |
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| 29 | .endm |
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| 30 | |
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| 31 | .macro ldrh1 reg, ptr, val |
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| 32 | user_ldst 9997f, ldtrh, \reg, \ptr, \val |
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| 33 | .endm |
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| 34 | |
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| 35 | .macro strh1 reg, ptr, val |
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| 36 | strh \reg, [\ptr], \val |
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| 37 | .endm |
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| 38 | |
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| 39 | .macro ldr1 reg, ptr, val |
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| 40 | user_ldst 9997f, ldtr, \reg, \ptr, \val |
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| 41 | .endm |
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| 42 | |
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| 43 | .macro str1 reg, ptr, val |
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| 44 | str \reg, [\ptr], \val |
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| 45 | .endm |
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| 46 | |
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| 47 | .macro ldp1 reg1, reg2, ptr, val |
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| 48 | user_ldp 9997f, \reg1, \reg2, \ptr, \val |
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| 49 | .endm |
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| 50 | |
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| 51 | .macro stp1 reg1, reg2, ptr, val |
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| 52 | stp \reg1, \reg2, [\ptr], \val |
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| 53 | .endm |
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| 54 | |
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| 55 | end .req x5 |
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| 56 | srcin .req x15 |
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| 57 | SYM_FUNC_START(__arch_copy_from_user) |
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| 58 | add end, x0, x2 |
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| 59 | mov srcin, x1 |
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| 60 | #include "copy_template.S" |
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| 61 | mov x0, #0 // Nothing to copy |
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| 62 | ret |
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| 63 | |
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| 64 | // Exception fixups |
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| 65 | 9997: cmp dst, dstin |
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| 66 | b.ne 9998f |
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| 67 | // Before being absolutely sure we couldn't copy anything, try harder |
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| 68 | USER(9998f, ldtrb tmp1w, [srcin]) |
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| 69 | strb tmp1w, [dst], #1 |
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| 70 | 9998: sub x0, end, dst // bytes not copied |
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| 71 | ret |
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| 72 | SYM_FUNC_END(__arch_copy_from_user) |
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| 73 | EXPORT_SYMBOL(__arch_copy_from_user) |
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| 74 | |
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