1 /*
2 * arch/xtensa/kernel/mcount.S
3 *
4 * Xtensa specific mcount support
5 *
6 * This file is subject to the terms and condi
7 * License. See the file "COPYING" in the mai
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 A
21 * a10: a0 of the caller in call0 ABI
22 *
23 * In call0 ABI the function _mcount is called
24 * its argument is in a10 and all the usual ar
25 * must be preserved in addition to callee-sav
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)
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