diff options
Diffstat (limited to 'arch/sparc64/kernel/ftrace.c')
-rw-r--r-- | arch/sparc64/kernel/ftrace.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c new file mode 100644 index 000000000000..f449e6df6c4a --- /dev/null +++ b/arch/sparc64/kernel/ftrace.c | |||
@@ -0,0 +1,99 @@ | |||
1 | #include <linux/spinlock.h> | ||
2 | #include <linux/hardirq.h> | ||
3 | #include <linux/ftrace.h> | ||
4 | #include <linux/percpu.h> | ||
5 | #include <linux/init.h> | ||
6 | #include <linux/list.h> | ||
7 | |||
8 | static const u32 ftrace_nop = 0x01000000; | ||
9 | |||
10 | notrace int ftrace_ip_converted(unsigned long ip) | ||
11 | { | ||
12 | u32 insn = *(u32 *) ip; | ||
13 | |||
14 | return (insn == ftrace_nop); | ||
15 | } | ||
16 | |||
17 | notrace unsigned char *ftrace_nop_replace(void) | ||
18 | { | ||
19 | return (char *)&ftrace_nop; | ||
20 | } | ||
21 | |||
22 | notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) | ||
23 | { | ||
24 | static u32 call; | ||
25 | s32 off; | ||
26 | |||
27 | off = ((s32)addr - (s32)ip); | ||
28 | call = 0x40000000 | ((u32)off >> 2); | ||
29 | |||
30 | return (unsigned char *) &call; | ||
31 | } | ||
32 | |||
33 | notrace int | ||
34 | ftrace_modify_code(unsigned long ip, unsigned char *old_code, | ||
35 | unsigned char *new_code) | ||
36 | { | ||
37 | u32 old = *(u32 *)old_code; | ||
38 | u32 new = *(u32 *)new_code; | ||
39 | u32 replaced; | ||
40 | int faulted; | ||
41 | |||
42 | __asm__ __volatile__( | ||
43 | "1: cas [%[ip]], %[old], %[new]\n" | ||
44 | " flush %[ip]\n" | ||
45 | " mov 0, %[faulted]\n" | ||
46 | "2:\n" | ||
47 | " .section .fixup,#alloc,#execinstr\n" | ||
48 | " .align 4\n" | ||
49 | "3: sethi %%hi(2b), %[faulted]\n" | ||
50 | " jmpl %[faulted] + %%lo(2b), %%g0\n" | ||
51 | " mov 1, %[faulted]\n" | ||
52 | " .previous\n" | ||
53 | " .section __ex_table,\"a\"\n" | ||
54 | " .align 4\n" | ||
55 | " .word 1b, 3b\n" | ||
56 | " .previous\n" | ||
57 | : "=r" (replaced), [faulted] "=r" (faulted) | ||
58 | : [new] "0" (new), [old] "r" (old), [ip] "r" (ip) | ||
59 | : "memory"); | ||
60 | |||
61 | if (replaced != old && replaced != new) | ||
62 | faulted = 2; | ||
63 | |||
64 | return faulted; | ||
65 | } | ||
66 | |||
67 | notrace int ftrace_update_ftrace_func(ftrace_func_t func) | ||
68 | { | ||
69 | unsigned long ip = (unsigned long)(&ftrace_call); | ||
70 | unsigned char old[4], *new; | ||
71 | |||
72 | memcpy(old, &ftrace_call, 4); | ||
73 | new = ftrace_call_replace(ip, (unsigned long)func); | ||
74 | return ftrace_modify_code(ip, old, new); | ||
75 | } | ||
76 | |||
77 | notrace int ftrace_mcount_set(unsigned long *data) | ||
78 | { | ||
79 | unsigned long ip = (long)(&mcount_call); | ||
80 | unsigned long *addr = data; | ||
81 | unsigned char old[4], *new; | ||
82 | |||
83 | /* | ||
84 | * Replace the mcount stub with a pointer to the | ||
85 | * ip recorder function. | ||
86 | */ | ||
87 | memcpy(old, &mcount_call, 4); | ||
88 | new = ftrace_call_replace(ip, *addr); | ||
89 | *addr = ftrace_modify_code(ip, old, new); | ||
90 | |||
91 | return 0; | ||
92 | } | ||
93 | |||
94 | |||
95 | int __init ftrace_dyn_arch_init(void *data) | ||
96 | { | ||
97 | ftrace_mcount_set(data); | ||
98 | return 0; | ||
99 | } | ||