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 KMSG_COMPONENT "perf"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11 #include <linux/kernel.h>
12 #include <linux/perf_event.h>
13 #include <linux/kvm_host.h>
14 #include <linux/percpu.h>
15 #include <linux/export.h>
16 #include <linux/seq_file.h>
17 #include <linux/spinlock.h>
18 #include <linux/uaccess.h>
19 #include <linux/compat.h>
20 #include <linux/sysfs.h>
21 #include <asm/stacktrace.h>
22 #include <asm/irq.h>
23 #include <asm/cpu_mf.h>
24 #include <asm/lowcore.h>
25 #include <asm/processor.h>
26 #include <asm/sysinfo.h>
27 #include <asm/unwind.h>
28
29 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
30 {
31 struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
32
33 if (!stack)
34 return NULL;
35
36 return (struct kvm_s390_sie_block *)stack->sie_control_block;
37 }
38
39 static bool is_in_guest(struct pt_regs *regs)
40 {
41 if (user_mode(regs))
42 return false;
43 #if IS_ENABLED(CONFIG_KVM)
44 return instruction_pointer(regs) == (unsigned long) &sie_exit;
45 #else
46 return false;
47 #endif
48 }
49
50 static unsigned long guest_is_user_mode(struct pt_regs *regs)
51 {
52 return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
53 }
54
55 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
56 {
57 return sie_block(regs)->gpsw.addr;
58 }
59
60 unsigned long perf_instruction_pointer(struct pt_regs *regs)
61 {
62 return is_in_guest(regs) ? instruction_pointer_guest(regs)
63 : instruction_pointer(regs);
64 }
65
66 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
67 {
68 return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
69 : PERF_RECORD_MISC_GUEST_KERNEL;
70 }
71
72 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
73 {
74 struct perf_sf_sde_regs *sde_regs;
75 unsigned long flags;
76
77 sde_regs = (struct perf_sf_sde_regs *) ®s->int_parm_long;
78 if (sde_regs->in_guest)
79 flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
80 : PERF_RECORD_MISC_GUEST_KERNEL;
81 else
82 flags = user_mode(regs) ? PERF_RECORD_MISC_USER
83 : PERF_RECORD_MISC_KERNEL;
84 return flags;
85 }
86
87 unsigned long perf_misc_flags(struct pt_regs *regs)
88 {
89 /* Check if the cpum_sf PMU has created the pt_regs structure.
90 * In this case, perf misc flags can be easily extracted. Otherwise,
91 * do regular checks on the pt_regs content.
92 */
93 if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
94 if (!regs->gprs[15])
95 return perf_misc_flags_sf(regs);
96
97 if (is_in_guest(regs))
98 return perf_misc_guest_flags(regs);
99
100 return user_mode(regs) ? PERF_RECORD_MISC_USER
101 : PERF_RECORD_MISC_KERNEL;
102 }
103
104 static void print_debug_cf(void)
105 {
106 struct cpumf_ctr_info cf_info;
107 int cpu = smp_processor_id();
108
109 memset(&cf_info, 0, sizeof(cf_info));
110 if (!qctri(&cf_info))
111 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
112 cpu, cf_info.cfvn, cf_info.csvn,
113 cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
114 }
115
116 static void print_debug_sf(void)
117 {
118 struct hws_qsi_info_block si;
119 int cpu = smp_processor_id();
120
121 memset(&si, 0, sizeof(si));
122 if (qsi(&si))
123 return;
124
125 pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
126 cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
127 si.cpu_speed);
128
129 if (si.as)
130 pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
131 " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
132 si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
133 if (si.ad)
134 pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
135 " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
136 si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
137 }
138
139 void perf_event_print_debug(void)
140 {
141 unsigned long flags;
142
143 local_irq_save(flags);
144 if (cpum_cf_avail())
145 print_debug_cf();
146 if (cpum_sf_avail())
147 print_debug_sf();
148 local_irq_restore(flags);
149 }
150
151 /* Service level infrastructure */
152 static void sl_print_counter(struct seq_file *m)
153 {
154 struct cpumf_ctr_info ci;
155
156 memset(&ci, 0, sizeof(ci));
157 if (qctri(&ci))
158 return;
159
160 seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
161 "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
162 }
163
164 static void sl_print_sampling(struct seq_file *m)
165 {
166 struct hws_qsi_info_block si;
167
168 memset(&si, 0, sizeof(si));
169 if (qsi(&si))
170 return;
171
172 if (!si.as && !si.ad)
173 return;
174
175 seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
176 " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
177 si.cpu_speed);
178 if (si.as)
179 seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
180 " sample_size=%u\n", si.bsdes);
181 if (si.ad)
182 seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
183 " sample_size=%u\n", si.dsdes);
184 }
185
186 static void service_level_perf_print(struct seq_file *m,
187 struct service_level *sl)
188 {
189 if (cpum_cf_avail())
190 sl_print_counter(m);
191 if (cpum_sf_avail())
192 sl_print_sampling(m);
193 }
194
195 static struct service_level service_level_perf = {
196 .seq_print = service_level_perf_print,
197 };
198
199 static int __init service_level_perf_register(void)
200 {
201 return register_service_level(&service_level_perf);
202 }
203 arch_initcall(service_level_perf_register);
204
205 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
206 struct pt_regs *regs)
207 {
208 struct unwind_state state;
209 unsigned long addr;
210
211 unwind_for_each_frame(&state, current, regs, 0) {
212 addr = unwind_get_return_address(&state);
213 if (!addr || perf_callchain_store(entry, addr))
214 return;
215 }
216 }
217
218 void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
219 struct pt_regs *regs)
220 {
221 arch_stack_walk_user_common(NULL, NULL, entry, regs, true);
222 }
223
224 /* Perf definitions for PMU event attributes in sysfs */
225 ssize_t cpumf_events_sysfs_show(struct device *dev,
226 struct device_attribute *attr, char *page)
227 {
228 struct perf_pmu_events_attr *pmu_attr;
229
230 pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
231 return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
232 }
233
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.