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1/**
2 * @file common.c
3 *
4 * @remark Copyright 2004 Oprofile Authors
5 * @remark Copyright 2010 ARM Ltd.
6 * @remark Read the file COPYING
7 *
8 * @author Zwane Mwaikambo
9 * @author Will Deacon [move to perf]
10 */
11
12#include <linux/cpumask.h>
13#include <linux/init.h>
14#include <linux/mutex.h>
15#include <linux/oprofile.h>
16#include <linux/perf_event.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19#include <asm/stacktrace.h>
20#include <linux/uaccess.h>
21
22#include <asm/perf_event.h>
23#include <asm/ptrace.h>
24
25#ifdef CONFIG_HW_PERF_EVENTS
26
27/*
28 * OProfile has a curious naming scheme for the ARM PMUs, but they are
29 * part of the user ABI so we need to map from the perf PMU name for
30 * supported PMUs.
31 */
32static struct op_perf_name {
33 char *perf_name;
34 char *op_name;
35} op_perf_name_map[] = {
36 { "xscale1", "arm/xscale1" },
37 { "xscale1", "arm/xscale2" },
38 { "v6", "arm/armv6" },
39 { "v6mpcore", "arm/mpcore" },
40 { "ARMv7 Cortex-A8", "arm/armv7" },
41 { "ARMv7 Cortex-A9", "arm/armv7-ca9" },
42};
43
44char *op_name_from_perf_id(void)
45{
46 int i;
47 struct op_perf_name names;
48 const char *perf_name = perf_pmu_name();
49
50 for (i = 0; i < ARRAY_SIZE(op_perf_name_map); ++i) {
51 names = op_perf_name_map[i];
52 if (!strcmp(names.perf_name, perf_name))
53 return names.op_name;
54 }
55
56 return NULL;
57}
58#endif
59
60static int report_trace(struct stackframe *frame, void *d)
61{
62 unsigned int *depth = d;
63
64 if (*depth) {
65 oprofile_add_trace(frame->pc);
66 (*depth)--;
67 }
68
69 return *depth == 0;
70}
71
72/*
73 * The registers we're interested in are at the end of the variable
74 * length saved register structure. The fp points at the end of this
75 * structure so the address of this struct is:
76 * (struct frame_tail *)(xxx->fp)-1
77 */
78struct frame_tail {
79 struct frame_tail *fp;
80 unsigned long sp;
81 unsigned long lr;
82} __attribute__((packed));
83
84static struct frame_tail* user_backtrace(struct frame_tail *tail)
85{
86 struct frame_tail buftail[2];
87
88 /* Also check accessibility of one struct frame_tail beyond */
89 if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
90 return NULL;
91 if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
92 return NULL;
93
94 oprofile_add_trace(buftail[0].lr);
95
96 /* frame pointers should strictly progress back up the stack
97 * (towards higher addresses) */
98 if (tail + 1 >= buftail[0].fp)
99 return NULL;
100
101 return buftail[0].fp-1;
102}
103
104static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
105{
106 struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
107
108 if (!user_mode(regs)) {
109 struct stackframe frame;
110 frame.fp = regs->ARM_fp;
111 frame.sp = regs->ARM_sp;
112 frame.lr = regs->ARM_lr;
113 frame.pc = regs->ARM_pc;
114 walk_stackframe(&frame, report_trace, &depth);
115 return;
116 }
117
118 while (depth-- && tail && !((unsigned long) tail & 3))
119 tail = user_backtrace(tail);
120}
121
122int __init oprofile_arch_init(struct oprofile_operations *ops)
123{
124 /* provide backtrace support also in timer mode: */
125 ops->backtrace = arm_backtrace;
126
127 return oprofile_perf_init(ops);
128}
129
130void oprofile_arch_exit(void)
131{
132 oprofile_perf_exit();
133}
1/**
2 * @file common.c
3 *
4 * @remark Copyright 2004 Oprofile Authors
5 * @remark Copyright 2010 ARM Ltd.
6 * @remark Read the file COPYING
7 *
8 * @author Zwane Mwaikambo
9 * @author Will Deacon [move to perf]
10 */
11
12#include <linux/cpumask.h>
13#include <linux/init.h>
14#include <linux/mutex.h>
15#include <linux/oprofile.h>
16#include <linux/perf_event.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19#include <asm/stacktrace.h>
20#include <linux/uaccess.h>
21
22#include <asm/perf_event.h>
23#include <asm/ptrace.h>
24
25#ifdef CONFIG_HW_PERF_EVENTS
26char *op_name_from_perf_id(void)
27{
28 enum arm_perf_pmu_ids id = armpmu_get_pmu_id();
29
30 switch (id) {
31 case ARM_PERF_PMU_ID_XSCALE1:
32 return "arm/xscale1";
33 case ARM_PERF_PMU_ID_XSCALE2:
34 return "arm/xscale2";
35 case ARM_PERF_PMU_ID_V6:
36 return "arm/armv6";
37 case ARM_PERF_PMU_ID_V6MP:
38 return "arm/mpcore";
39 case ARM_PERF_PMU_ID_CA8:
40 return "arm/armv7";
41 case ARM_PERF_PMU_ID_CA9:
42 return "arm/armv7-ca9";
43 default:
44 return NULL;
45 }
46}
47#endif
48
49static int report_trace(struct stackframe *frame, void *d)
50{
51 unsigned int *depth = d;
52
53 if (*depth) {
54 oprofile_add_trace(frame->pc);
55 (*depth)--;
56 }
57
58 return *depth == 0;
59}
60
61/*
62 * The registers we're interested in are at the end of the variable
63 * length saved register structure. The fp points at the end of this
64 * structure so the address of this struct is:
65 * (struct frame_tail *)(xxx->fp)-1
66 */
67struct frame_tail {
68 struct frame_tail *fp;
69 unsigned long sp;
70 unsigned long lr;
71} __attribute__((packed));
72
73static struct frame_tail* user_backtrace(struct frame_tail *tail)
74{
75 struct frame_tail buftail[2];
76
77 /* Also check accessibility of one struct frame_tail beyond */
78 if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
79 return NULL;
80 if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
81 return NULL;
82
83 oprofile_add_trace(buftail[0].lr);
84
85 /* frame pointers should strictly progress back up the stack
86 * (towards higher addresses) */
87 if (tail + 1 >= buftail[0].fp)
88 return NULL;
89
90 return buftail[0].fp-1;
91}
92
93static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
94{
95 struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
96
97 if (!user_mode(regs)) {
98 struct stackframe frame;
99 frame.fp = regs->ARM_fp;
100 frame.sp = regs->ARM_sp;
101 frame.lr = regs->ARM_lr;
102 frame.pc = regs->ARM_pc;
103 walk_stackframe(&frame, report_trace, &depth);
104 return;
105 }
106
107 while (depth-- && tail && !((unsigned long) tail & 3))
108 tail = user_backtrace(tail);
109}
110
111int __init oprofile_arch_init(struct oprofile_operations *ops)
112{
113 /* provide backtrace support also in timer mode: */
114 ops->backtrace = arm_backtrace;
115
116 return oprofile_perf_init(ops);
117}
118
119void oprofile_arch_exit(void)
120{
121 oprofile_perf_exit();
122}