1 /*
2 * Performance event support for s390x
3 *
4 * Copyright IBM Corp. 2012
5 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License (version 2 only)
9 * as published by the Free Software Foundation.
10 */
11 #define KMSG_COMPONENT "perf"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13
14 #include <linux/kernel.h>
15 #include <linux/perf_event.h>
16 #include <linux/percpu.h>
17 #include <linux/export.h>
18 #include <asm/irq.h>
19 #include <asm/cpu_mf.h>
20 #include <asm/lowcore.h>
21 #include <asm/processor.h>
22
perf_pmu_name(void)23 const char *perf_pmu_name(void)
24 {
25 if (cpum_cf_avail() || cpum_sf_avail())
26 return "CPU-measurement facilities (CPUMF)";
27 return "pmu";
28 }
29 EXPORT_SYMBOL(perf_pmu_name);
30
perf_num_counters(void)31 int perf_num_counters(void)
32 {
33 int num = 0;
34
35 if (cpum_cf_avail())
36 num += PERF_CPUM_CF_MAX_CTR;
37
38 return num;
39 }
40 EXPORT_SYMBOL(perf_num_counters);
41
perf_event_print_debug(void)42 void perf_event_print_debug(void)
43 {
44 struct cpumf_ctr_info cf_info;
45 unsigned long flags;
46 int cpu;
47
48 if (!cpum_cf_avail())
49 return;
50
51 local_irq_save(flags);
52
53 cpu = smp_processor_id();
54 memset(&cf_info, 0, sizeof(cf_info));
55 if (!qctri(&cf_info)) {
56 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
57 cpu, cf_info.cfvn, cf_info.csvn,
58 cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
59 print_hex_dump_bytes("CPUMF Query: ", DUMP_PREFIX_OFFSET,
60 &cf_info, sizeof(cf_info));
61 }
62
63 local_irq_restore(flags);
64 }
65
66 /* See also arch/s390/kernel/traps.c */
__store_trace(struct perf_callchain_entry * entry,unsigned long sp,unsigned long low,unsigned long high)67 static unsigned long __store_trace(struct perf_callchain_entry *entry,
68 unsigned long sp,
69 unsigned long low, unsigned long high)
70 {
71 struct stack_frame *sf;
72 struct pt_regs *regs;
73
74 while (1) {
75 sp = sp & PSW_ADDR_INSN;
76 if (sp < low || sp > high - sizeof(*sf))
77 return sp;
78 sf = (struct stack_frame *) sp;
79 perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
80 /* Follow the backchain. */
81 while (1) {
82 low = sp;
83 sp = sf->back_chain & PSW_ADDR_INSN;
84 if (!sp)
85 break;
86 if (sp <= low || sp > high - sizeof(*sf))
87 return sp;
88 sf = (struct stack_frame *) sp;
89 perf_callchain_store(entry,
90 sf->gprs[8] & PSW_ADDR_INSN);
91 }
92 /* Zero backchain detected, check for interrupt frame. */
93 sp = (unsigned long) (sf + 1);
94 if (sp <= low || sp > high - sizeof(*regs))
95 return sp;
96 regs = (struct pt_regs *) sp;
97 perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
98 low = sp;
99 sp = regs->gprs[15];
100 }
101 }
102
perf_callchain_kernel(struct perf_callchain_entry * entry,struct pt_regs * regs)103 void perf_callchain_kernel(struct perf_callchain_entry *entry,
104 struct pt_regs *regs)
105 {
106 unsigned long head;
107 struct stack_frame *head_sf;
108
109 if (user_mode(regs))
110 return;
111
112 head = regs->gprs[15];
113 head_sf = (struct stack_frame *) head;
114
115 if (!head_sf || !head_sf->back_chain)
116 return;
117
118 head = head_sf->back_chain;
119 head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE,
120 S390_lowcore.async_stack);
121
122 __store_trace(entry, head, S390_lowcore.thread_info,
123 S390_lowcore.thread_info + THREAD_SIZE);
124 }
125