| 1 | /*
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| 2 | * arch/xtensa/kernel/mcount.S
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| 3 | *
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| 4 | * Xtensa specific mcount support
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| 5 | *
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| 6 | * This file is subject to the terms and conditions of the GNU General Public
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| 7 | * License. See the file "COPYING" in the main directory of this archive
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| 8 | * for more details.
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| 9 | *
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| 10 | * Copyright (C) 2013 Tensilica Inc.
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| 11 | */
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| 12 |
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| 13 | |
| 14 | |
| 15 | |
| 16 |
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| 17 | /*
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| 18 | * Entry condition:
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| 19 | *
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| 20 | * a2: a0 of the caller in windowed ABI
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| 21 | * a10: a0 of the caller in call0 ABI
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| 22 | *
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| 23 | * In call0 ABI the function _mcount is called with the special ABI:
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| 24 | * its argument is in a10 and all the usual argument registers (a2 - a7)
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| 25 | * must be preserved in addition to callee-saved a12 - a15.
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| 26 | */
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| 27 |
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| 28 | ENTRY(_mcount)
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| 29 | |
| 30 | abi_entry_default
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| 31 |
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| 32 | movi a4, ftrace_trace_function
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| 33 | l32i a4, a4, 0
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| 34 | movi a3, ftrace_stub
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| 35 | bne a3, a4, 1f
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| 36 | abi_ret_default
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| 37 |
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| 38 | 1: xor a7, a2, a1
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| 39 | movi a3, 0x3fffffff
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| 40 | and a7, a7, a3
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| 41 | xor a7, a7, a1
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| 42 |
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| 43 | xor a6, a0, a1
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| 44 | and a6, a6, a3
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| 45 | xor a6, a6, a1
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| 46 | addi a6, a6, -MCOUNT_INSN_SIZE
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| 47 | callx4 a4
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| 48 |
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| 49 | abi_ret_default
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| 50 | |
| 51 | abi_entry_default
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| 52 |
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| 53 | movi a9, ftrace_trace_function
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| 54 | l32i a9, a9, 0
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| 55 | movi a11, ftrace_stub
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| 56 | bne a9, a11, 1f
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| 57 | abi_ret_default
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| 58 |
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| 59 | 1: abi_entry(28)
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| 60 | s32i a0, sp, 0
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| 61 | s32i a2, sp, 4
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| 62 | s32i a3, sp, 8
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| 63 | s32i a4, sp, 12
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| 64 | s32i a5, sp, 16
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| 65 | s32i a6, sp, 20
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| 66 | s32i a7, sp, 24
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| 67 | addi a2, a10, -MCOUNT_INSN_SIZE
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| 68 | callx0 a9
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| 69 | l32i a0, sp, 0
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| 70 | l32i a2, sp, 4
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| 71 | l32i a3, sp, 8
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| 72 | l32i a4, sp, 12
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| 73 | l32i a5, sp, 16
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| 74 | l32i a6, sp, 20
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| 75 | l32i a7, sp, 24
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| 76 | abi_ret(28)
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| 77 | |
| 78 | |
| 79 | |
| 80 | ENDPROC(_mcount)
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| 81 | EXPORT_SYMBOL(_mcount)
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| 82 |
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| 83 | ENTRY(ftrace_stub)
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| 84 | abi_entry_default
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| 85 | abi_ret_default
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| 86 | ENDPROC(ftrace_stub)
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