1*4882a593Smuzhiyun /**
2*4882a593Smuzhiyun * @file common.c
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * @remark Copyright 2004 Oprofile Authors
5*4882a593Smuzhiyun * @remark Copyright 2010 ARM Ltd.
6*4882a593Smuzhiyun * @remark Read the file COPYING
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * @author Zwane Mwaikambo
9*4882a593Smuzhiyun * @author Will Deacon [move to perf]
10*4882a593Smuzhiyun */
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/cpumask.h>
13*4882a593Smuzhiyun #include <linux/init.h>
14*4882a593Smuzhiyun #include <linux/mutex.h>
15*4882a593Smuzhiyun #include <linux/oprofile.h>
16*4882a593Smuzhiyun #include <linux/perf_event.h>
17*4882a593Smuzhiyun #include <linux/platform_device.h>
18*4882a593Smuzhiyun #include <linux/slab.h>
19*4882a593Smuzhiyun #include <asm/stacktrace.h>
20*4882a593Smuzhiyun #include <linux/uaccess.h>
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun #include <asm/perf_event.h>
23*4882a593Smuzhiyun #include <asm/ptrace.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #ifdef CONFIG_HW_PERF_EVENTS
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /*
28*4882a593Smuzhiyun * OProfile has a curious naming scheme for the ARM PMUs, but they are
29*4882a593Smuzhiyun * part of the user ABI so we need to map from the perf PMU name for
30*4882a593Smuzhiyun * supported PMUs.
31*4882a593Smuzhiyun */
32*4882a593Smuzhiyun static struct op_perf_name {
33*4882a593Smuzhiyun char *perf_name;
34*4882a593Smuzhiyun char *op_name;
35*4882a593Smuzhiyun } op_perf_name_map[] = {
36*4882a593Smuzhiyun { "armv5_xscale1", "arm/xscale1" },
37*4882a593Smuzhiyun { "armv5_xscale2", "arm/xscale2" },
38*4882a593Smuzhiyun { "armv6_1136", "arm/armv6" },
39*4882a593Smuzhiyun { "armv6_1156", "arm/armv6" },
40*4882a593Smuzhiyun { "armv6_1176", "arm/armv6" },
41*4882a593Smuzhiyun { "armv6_11mpcore", "arm/mpcore" },
42*4882a593Smuzhiyun { "armv7_cortex_a8", "arm/armv7" },
43*4882a593Smuzhiyun { "armv7_cortex_a9", "arm/armv7-ca9" },
44*4882a593Smuzhiyun };
45*4882a593Smuzhiyun
op_name_from_perf_id(void)46*4882a593Smuzhiyun char *op_name_from_perf_id(void)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun int i;
49*4882a593Smuzhiyun struct op_perf_name names;
50*4882a593Smuzhiyun const char *perf_name = perf_pmu_name();
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(op_perf_name_map); ++i) {
53*4882a593Smuzhiyun names = op_perf_name_map[i];
54*4882a593Smuzhiyun if (!strcmp(names.perf_name, perf_name))
55*4882a593Smuzhiyun return names.op_name;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return NULL;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun #endif
61*4882a593Smuzhiyun
report_trace(struct stackframe * frame,void * d)62*4882a593Smuzhiyun static int report_trace(struct stackframe *frame, void *d)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun unsigned int *depth = d;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun if (*depth) {
67*4882a593Smuzhiyun oprofile_add_trace(frame->pc);
68*4882a593Smuzhiyun (*depth)--;
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun return *depth == 0;
72*4882a593Smuzhiyun }
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun /*
75*4882a593Smuzhiyun * The registers we're interested in are at the end of the variable
76*4882a593Smuzhiyun * length saved register structure. The fp points at the end of this
77*4882a593Smuzhiyun * structure so the address of this struct is:
78*4882a593Smuzhiyun * (struct frame_tail *)(xxx->fp)-1
79*4882a593Smuzhiyun */
80*4882a593Smuzhiyun struct frame_tail {
81*4882a593Smuzhiyun struct frame_tail *fp;
82*4882a593Smuzhiyun unsigned long sp;
83*4882a593Smuzhiyun unsigned long lr;
84*4882a593Smuzhiyun } __attribute__((packed));
85*4882a593Smuzhiyun
user_backtrace(struct frame_tail * tail)86*4882a593Smuzhiyun static struct frame_tail* user_backtrace(struct frame_tail *tail)
87*4882a593Smuzhiyun {
88*4882a593Smuzhiyun struct frame_tail buftail[2];
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun /* Also check accessibility of one struct frame_tail beyond */
91*4882a593Smuzhiyun if (!access_ok(tail, sizeof(buftail)))
92*4882a593Smuzhiyun return NULL;
93*4882a593Smuzhiyun if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
94*4882a593Smuzhiyun return NULL;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun oprofile_add_trace(buftail[0].lr);
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun /* frame pointers should strictly progress back up the stack
99*4882a593Smuzhiyun * (towards higher addresses) */
100*4882a593Smuzhiyun if (tail + 1 >= buftail[0].fp)
101*4882a593Smuzhiyun return NULL;
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun return buftail[0].fp-1;
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
arm_backtrace(struct pt_regs * const regs,unsigned int depth)106*4882a593Smuzhiyun static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
107*4882a593Smuzhiyun {
108*4882a593Smuzhiyun struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun if (!user_mode(regs)) {
111*4882a593Smuzhiyun struct stackframe frame;
112*4882a593Smuzhiyun arm_get_current_stackframe(regs, &frame);
113*4882a593Smuzhiyun walk_stackframe(&frame, report_trace, &depth);
114*4882a593Smuzhiyun return;
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun while (depth-- && tail && !((unsigned long) tail & 3))
118*4882a593Smuzhiyun tail = user_backtrace(tail);
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun
oprofile_arch_init(struct oprofile_operations * ops)121*4882a593Smuzhiyun int __init oprofile_arch_init(struct oprofile_operations *ops)
122*4882a593Smuzhiyun {
123*4882a593Smuzhiyun /* provide backtrace support also in timer mode: */
124*4882a593Smuzhiyun ops->backtrace = arm_backtrace;
125*4882a593Smuzhiyun
126*4882a593Smuzhiyun return oprofile_perf_init(ops);
127*4882a593Smuzhiyun }
128*4882a593Smuzhiyun
oprofile_arch_exit(void)129*4882a593Smuzhiyun void oprofile_arch_exit(void)
130*4882a593Smuzhiyun {
131*4882a593Smuzhiyun oprofile_perf_exit();
132*4882a593Smuzhiyun }
133