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c49f6353 AB |
1 | #include <linux/percpu.h> |
2 | #include <linux/jump_label.h> | |
3 | #include <asm/trace.h> | |
4 | ||
d4fe0965 | 5 | #ifdef HAVE_JUMP_LABEL |
c49f6353 AB |
6 | struct static_key opal_tracepoint_key = STATIC_KEY_INIT; |
7 | ||
8 | void opal_tracepoint_regfunc(void) | |
9 | { | |
10 | static_key_slow_inc(&opal_tracepoint_key); | |
11 | } | |
12 | ||
13 | void opal_tracepoint_unregfunc(void) | |
14 | { | |
15 | static_key_slow_dec(&opal_tracepoint_key); | |
16 | } | |
17 | #else | |
18 | /* | |
19 | * We optimise OPAL calls by placing opal_tracepoint_refcount | |
20 | * directly in the TOC so we can check if the opal tracepoints are | |
21 | * enabled via a single load. | |
22 | */ | |
23 | ||
24 | /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ | |
25 | extern long opal_tracepoint_refcount; | |
26 | ||
27 | void opal_tracepoint_regfunc(void) | |
28 | { | |
29 | opal_tracepoint_refcount++; | |
30 | } | |
31 | ||
32 | void opal_tracepoint_unregfunc(void) | |
33 | { | |
34 | opal_tracepoint_refcount--; | |
35 | } | |
36 | #endif | |
37 | ||
38 | /* | |
39 | * Since the tracing code might execute OPAL calls we need to guard against | |
40 | * recursion. | |
41 | */ | |
42 | static DEFINE_PER_CPU(unsigned int, opal_trace_depth); | |
43 | ||
44 | void __trace_opal_entry(unsigned long opcode, unsigned long *args) | |
45 | { | |
46 | unsigned long flags; | |
47 | unsigned int *depth; | |
48 | ||
49 | local_irq_save(flags); | |
50 | ||
51 | depth = &__get_cpu_var(opal_trace_depth); | |
52 | ||
53 | if (*depth) | |
54 | goto out; | |
55 | ||
56 | (*depth)++; | |
57 | preempt_disable(); | |
58 | trace_opal_entry(opcode, args); | |
59 | (*depth)--; | |
60 | ||
61 | out: | |
62 | local_irq_restore(flags); | |
63 | } | |
64 | ||
65 | void __trace_opal_exit(long opcode, unsigned long retval) | |
66 | { | |
67 | unsigned long flags; | |
68 | unsigned int *depth; | |
69 | ||
70 | local_irq_save(flags); | |
71 | ||
72 | depth = &__get_cpu_var(opal_trace_depth); | |
73 | ||
74 | if (*depth) | |
75 | goto out; | |
76 | ||
77 | (*depth)++; | |
78 | trace_opal_exit(opcode, retval); | |
79 | preempt_enable(); | |
80 | (*depth)--; | |
81 | ||
82 | out: | |
83 | local_irq_restore(flags); | |
84 | } |