| 1 | /* |
|---|
| 2 | * arch/xtensa/kernel/mcount.S |
|---|
| 3 | * |
|---|
| 4 | * Xtensa specific mcount support |
|---|
| 5 | * |
|---|
| 6 | * This file is subject to the terms and conditions of the GNU General Public |
|---|
| 7 | * License. See the file "COPYING" in the main directory of this archive |
|---|
| 8 | * for more details. |
|---|
| 9 | * |
|---|
| 10 | * Copyright (C) 2013 Tensilica Inc. |
|---|
| 11 | */ |
|---|
| 12 | |
|---|
| 13 | #include <linux/linkage.h> |
|---|
| 14 | #include <asm/asmmacro.h> |
|---|
| 15 | #include <asm/ftrace.h> |
|---|
| 16 | |
|---|
| 17 | /* |
|---|
| 18 | * Entry condition: |
|---|
| 19 | * |
|---|
| 20 | * a2: a0 of the caller in windowed ABI |
|---|
| 21 | * a10: a0 of the caller in call0 ABI |
|---|
| 22 | * |
|---|
| 23 | * In call0 ABI the function _mcount is called with the special ABI: |
|---|
| 24 | * its argument is in a10 and all the usual argument registers (a2 - a7) |
|---|
| 25 | * must be preserved in addition to callee-saved a12 - a15. |
|---|
| 26 | */ |
|---|
| 27 | |
|---|
| 28 | ENTRY(_mcount) |
|---|
| 29 | #if defined(__XTENSA_WINDOWED_ABI__) |
|---|
| 30 | abi_entry_default |
|---|
| 31 | |
|---|
| 32 | movi a4, ftrace_trace_function |
|---|
| 33 | l32i a4, a4, 0 |
|---|
| 34 | movi a3, ftrace_stub |
|---|
| 35 | bne a3, a4, 1f |
|---|
| 36 | abi_ret_default |
|---|
| 37 | |
|---|
| 38 | 1: xor a7, a2, a1 |
|---|
| 39 | movi a3, 0x3fffffff |
|---|
| 40 | and a7, a7, a3 |
|---|
| 41 | xor a7, a7, a1 |
|---|
| 42 | |
|---|
| 43 | xor a6, a0, a1 |
|---|
| 44 | and a6, a6, a3 |
|---|
| 45 | xor a6, a6, a1 |
|---|
| 46 | addi a6, a6, -MCOUNT_INSN_SIZE |
|---|
| 47 | callx4 a4 |
|---|
| 48 | |
|---|
| 49 | abi_ret_default |
|---|
| 50 | #elif defined(__XTENSA_CALL0_ABI__) |
|---|
| 51 | abi_entry_default |
|---|
| 52 | |
|---|
| 53 | movi a9, ftrace_trace_function |
|---|
| 54 | l32i a9, a9, 0 |
|---|
| 55 | movi a11, ftrace_stub |
|---|
| 56 | bne a9, a11, 1f |
|---|
| 57 | abi_ret_default |
|---|
| 58 | |
|---|
| 59 | 1: abi_entry(28) |
|---|
| 60 | s32i a0, sp, 0 |
|---|
| 61 | s32i a2, sp, 4 |
|---|
| 62 | s32i a3, sp, 8 |
|---|
| 63 | s32i a4, sp, 12 |
|---|
| 64 | s32i a5, sp, 16 |
|---|
| 65 | s32i a6, sp, 20 |
|---|
| 66 | s32i a7, sp, 24 |
|---|
| 67 | addi a2, a10, -MCOUNT_INSN_SIZE |
|---|
| 68 | callx0 a9 |
|---|
| 69 | l32i a0, sp, 0 |
|---|
| 70 | l32i a2, sp, 4 |
|---|
| 71 | l32i a3, sp, 8 |
|---|
| 72 | l32i a4, sp, 12 |
|---|
| 73 | l32i a5, sp, 16 |
|---|
| 74 | l32i a6, sp, 20 |
|---|
| 75 | l32i a7, sp, 24 |
|---|
| 76 | abi_ret(28) |
|---|
| 77 | #else |
|---|
| 78 | #error Unsupported Xtensa ABI |
|---|
| 79 | #endif |
|---|
| 80 | ENDPROC(_mcount) |
|---|
| 81 | EXPORT_SYMBOL(_mcount) |
|---|
| 82 | |
|---|
| 83 | ENTRY(ftrace_stub) |
|---|
| 84 | abi_entry_default |
|---|
| 85 | abi_ret_default |
|---|
| 86 | ENDPROC(ftrace_stub) |
|---|
| 87 | |
|---|
