xref: /linux/arch/s390/kernel/perf_event.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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/sysfs.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 
26 const char *perf_pmu_name(void)
27 {
28 	if (cpum_cf_avail() || cpum_sf_avail())
29 		return "CPU-Measurement Facilities (CPU-MF)";
30 	return "pmu";
31 }
32 EXPORT_SYMBOL(perf_pmu_name);
33 
34 int perf_num_counters(void)
35 {
36 	int num = 0;
37 
38 	if (cpum_cf_avail())
39 		num += PERF_CPUM_CF_MAX_CTR;
40 	if (cpum_sf_avail())
41 		num += PERF_CPUM_SF_MAX_CTR;
42 
43 	return num;
44 }
45 EXPORT_SYMBOL(perf_num_counters);
46 
47 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
48 {
49 	struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
50 
51 	if (!stack)
52 		return NULL;
53 
54 	return (struct kvm_s390_sie_block *) stack->empty1[0];
55 }
56 
57 static bool is_in_guest(struct pt_regs *regs)
58 {
59 	if (user_mode(regs))
60 		return false;
61 #if IS_ENABLED(CONFIG_KVM)
62 	return instruction_pointer(regs) == (unsigned long) &sie_exit;
63 #else
64 	return false;
65 #endif
66 }
67 
68 static unsigned long guest_is_user_mode(struct pt_regs *regs)
69 {
70 	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
71 }
72 
73 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
74 {
75 	return sie_block(regs)->gpsw.addr;
76 }
77 
78 unsigned long perf_instruction_pointer(struct pt_regs *regs)
79 {
80 	return is_in_guest(regs) ? instruction_pointer_guest(regs)
81 				 : instruction_pointer(regs);
82 }
83 
84 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
85 {
86 	return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
87 					: PERF_RECORD_MISC_GUEST_KERNEL;
88 }
89 
90 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
91 {
92 	struct perf_sf_sde_regs *sde_regs;
93 	unsigned long flags;
94 
95 	sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
96 	if (sde_regs->in_guest)
97 		flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
98 					: PERF_RECORD_MISC_GUEST_KERNEL;
99 	else
100 		flags = user_mode(regs) ? PERF_RECORD_MISC_USER
101 					: PERF_RECORD_MISC_KERNEL;
102 	return flags;
103 }
104 
105 unsigned long perf_misc_flags(struct pt_regs *regs)
106 {
107 	/* Check if the cpum_sf PMU has created the pt_regs structure.
108 	 * In this case, perf misc flags can be easily extracted.  Otherwise,
109 	 * do regular checks on the pt_regs content.
110 	 */
111 	if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
112 		if (!regs->gprs[15])
113 			return perf_misc_flags_sf(regs);
114 
115 	if (is_in_guest(regs))
116 		return perf_misc_guest_flags(regs);
117 
118 	return user_mode(regs) ? PERF_RECORD_MISC_USER
119 			       : PERF_RECORD_MISC_KERNEL;
120 }
121 
122 static void print_debug_cf(void)
123 {
124 	struct cpumf_ctr_info cf_info;
125 	int cpu = smp_processor_id();
126 
127 	memset(&cf_info, 0, sizeof(cf_info));
128 	if (!qctri(&cf_info))
129 		pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
130 			cpu, cf_info.cfvn, cf_info.csvn,
131 			cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
132 }
133 
134 static void print_debug_sf(void)
135 {
136 	struct hws_qsi_info_block si;
137 	int cpu = smp_processor_id();
138 
139 	memset(&si, 0, sizeof(si));
140 	if (qsi(&si))
141 		return;
142 
143 	pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
144 		cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
145 		si.cpu_speed);
146 
147 	if (si.as)
148 		pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
149 			" bsdes=%i tear=%016lx dear=%016lx\n", cpu,
150 			si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
151 	if (si.ad)
152 		pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
153 			" dsdes=%i tear=%016lx dear=%016lx\n", cpu,
154 			si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
155 }
156 
157 void perf_event_print_debug(void)
158 {
159 	unsigned long flags;
160 
161 	local_irq_save(flags);
162 	if (cpum_cf_avail())
163 		print_debug_cf();
164 	if (cpum_sf_avail())
165 		print_debug_sf();
166 	local_irq_restore(flags);
167 }
168 
169 /* Service level infrastructure */
170 static void sl_print_counter(struct seq_file *m)
171 {
172 	struct cpumf_ctr_info ci;
173 
174 	memset(&ci, 0, sizeof(ci));
175 	if (qctri(&ci))
176 		return;
177 
178 	seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
179 		   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
180 }
181 
182 static void sl_print_sampling(struct seq_file *m)
183 {
184 	struct hws_qsi_info_block si;
185 
186 	memset(&si, 0, sizeof(si));
187 	if (qsi(&si))
188 		return;
189 
190 	if (!si.as && !si.ad)
191 		return;
192 
193 	seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
194 		   " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
195 		   si.cpu_speed);
196 	if (si.as)
197 		seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
198 			   " sample_size=%u\n", si.bsdes);
199 	if (si.ad)
200 		seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
201 			   " sample_size=%u\n", si.dsdes);
202 }
203 
204 static void service_level_perf_print(struct seq_file *m,
205 				     struct service_level *sl)
206 {
207 	if (cpum_cf_avail())
208 		sl_print_counter(m);
209 	if (cpum_sf_avail())
210 		sl_print_sampling(m);
211 }
212 
213 static struct service_level service_level_perf = {
214 	.seq_print = service_level_perf_print,
215 };
216 
217 static int __init service_level_perf_register(void)
218 {
219 	return register_service_level(&service_level_perf);
220 }
221 arch_initcall(service_level_perf_register);
222 
223 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
224 			   struct pt_regs *regs)
225 {
226 	struct unwind_state state;
227 
228 	unwind_for_each_frame(&state, current, regs, 0)
229 		perf_callchain_store(entry, state.ip);
230 }
231 
232 /* Perf definitions for PMU event attributes in sysfs */
233 ssize_t cpumf_events_sysfs_show(struct device *dev,
234 				struct device_attribute *attr, char *page)
235 {
236 	struct perf_pmu_events_attr *pmu_attr;
237 
238 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
239 	return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
240 }
241