1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Performance event support for s390x
4 *
5 * Copyright IBM Corp. 2012, 2013
6 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
7 */
8#define pr_fmt(fmt) "perf: " fmt
9
10#include <linux/kernel.h>
11#include <linux/perf_event.h>
12#include <linux/kvm_host.h>
13#include <linux/percpu.h>
14#include <linux/seq_file.h>
15#include <linux/spinlock.h>
16#include <linux/uaccess.h>
17#include <linux/sysfs.h>
18#include <asm/stacktrace.h>
19#include <asm/irq.h>
20#include <asm/cpu_mf.h>
21#include <asm/lowcore.h>
22#include <asm/processor.h>
23#include <asm/sysinfo.h>
24#include <asm/unwind.h>
25
26static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
27{
28 struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
29
30 if (!stack)
31 return NULL;
32
33 return (struct kvm_s390_sie_block *)stack->sie_control_block;
34}
35
36static bool is_in_guest(struct pt_regs *regs)
37{
38 if (user_mode(regs))
39 return false;
40#if IS_ENABLED(CONFIG_KVM)
41 return instruction_pointer(regs) == (unsigned long) &sie_exit;
42#else
43 return false;
44#endif
45}
46
47static unsigned long guest_is_user_mode(struct pt_regs *regs)
48{
49 return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
50}
51
52static unsigned long instruction_pointer_guest(struct pt_regs *regs)
53{
54 return sie_block(regs)->gpsw.addr;
55}
56
57unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
58{
59 return is_in_guest(regs) ? instruction_pointer_guest(regs)
60 : instruction_pointer(regs);
61}
62
63static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
64{
65 return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
66 : PERF_RECORD_MISC_GUEST_KERNEL;
67}
68
69static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
70{
71 struct perf_sf_sde_regs *sde_regs;
72 unsigned long flags;
73
74 sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
75 if (sde_regs->in_guest)
76 flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
77 : PERF_RECORD_MISC_GUEST_KERNEL;
78 else
79 flags = user_mode(regs) ? PERF_RECORD_MISC_USER
80 : PERF_RECORD_MISC_KERNEL;
81 return flags;
82}
83
84unsigned long perf_arch_misc_flags(struct pt_regs *regs)
85{
86 /* Check if the cpum_sf PMU has created the pt_regs structure.
87 * In this case, perf misc flags can be easily extracted. Otherwise,
88 * do regular checks on the pt_regs content.
89 */
90 if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
91 if (!regs->gprs[15])
92 return perf_misc_flags_sf(regs);
93
94 if (is_in_guest(regs))
95 return perf_misc_guest_flags(regs);
96
97 return user_mode(regs) ? PERF_RECORD_MISC_USER
98 : PERF_RECORD_MISC_KERNEL;
99}
100
101static void print_debug_cf(void)
102{
103 struct cpumf_ctr_info cf_info;
104 int cpu = smp_processor_id();
105
106 memset(&cf_info, 0, sizeof(cf_info));
107 if (!qctri(&cf_info))
108 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
109 cpu, cf_info.cfvn, cf_info.csvn,
110 cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
111}
112
113static void print_debug_sf(void)
114{
115 struct hws_qsi_info_block si;
116 int cpu = smp_processor_id();
117
118 memset(&si, 0, sizeof(si));
119 if (qsi(&si))
120 return;
121
122 pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
123 cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
124 si.cpu_speed);
125
126 if (si.as)
127 pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
128 " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
129 si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
130 if (si.ad)
131 pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
132 " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
133 si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
134}
135
136void perf_event_print_debug(void)
137{
138 unsigned long flags;
139
140 local_irq_save(flags);
141 if (cpum_cf_avail())
142 print_debug_cf();
143 if (cpum_sf_avail())
144 print_debug_sf();
145 local_irq_restore(flags);
146}
147
148/* Service level infrastructure */
149static void sl_print_counter(struct seq_file *m)
150{
151 struct cpumf_ctr_info ci;
152
153 memset(&ci, 0, sizeof(ci));
154 if (qctri(&ci))
155 return;
156
157 seq_printf(m, fmt: "CPU-MF: Counter facility: version=%u.%u "
158 "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
159}
160
161static void sl_print_sampling(struct seq_file *m)
162{
163 struct hws_qsi_info_block si;
164
165 memset(&si, 0, sizeof(si));
166 if (qsi(&si))
167 return;
168
169 if (!si.as && !si.ad)
170 return;
171
172 seq_printf(m, fmt: "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
173 " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
174 si.cpu_speed);
175 if (si.as)
176 seq_printf(m, fmt: "CPU-MF: Sampling facility: mode=basic"
177 " sample_size=%u\n", si.bsdes);
178 if (si.ad)
179 seq_printf(m, fmt: "CPU-MF: Sampling facility: mode=diagnostic"
180 " sample_size=%u\n", si.dsdes);
181}
182
183static void service_level_perf_print(struct seq_file *m,
184 struct service_level *sl)
185{
186 if (cpum_cf_avail())
187 sl_print_counter(m);
188 if (cpum_sf_avail())
189 sl_print_sampling(m);
190}
191
192static struct service_level service_level_perf = {
193 .seq_print = service_level_perf_print,
194};
195
196static int __init service_level_perf_register(void)
197{
198 return register_service_level(&service_level_perf);
199}
200arch_initcall(service_level_perf_register);
201
202void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
203 struct pt_regs *regs)
204{
205 struct unwind_state state;
206 unsigned long addr;
207
208 unwind_for_each_frame(&state, current, regs, 0) {
209 addr = unwind_get_return_address(state: &state);
210 if (!addr || perf_callchain_store(ctx: entry, ip: addr))
211 return;
212 }
213}
214
215void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
216 struct pt_regs *regs)
217{
218 arch_stack_walk_user_common(NULL, NULL, entry, regs, true);
219}
220
221/* Perf definitions for PMU event attributes in sysfs */
222ssize_t cpumf_events_sysfs_show(struct device *dev,
223 struct device_attribute *attr, char *page)
224{
225 struct perf_pmu_events_attr *pmu_attr;
226
227 pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
228 return sysfs_emit(buf: page, fmt: "event=0x%04llx\n", pmu_attr->id);
229}
230

source code of linux/arch/s390/kernel/perf_event.c