xref: /openbmc/linux/arch/s390/kernel/perf_event.c (revision 7bcae826)
1 /*
2  * Performance event support for s390x
3  *
4  *  Copyright IBM Corp. 2012, 2013
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/kvm_host.h>
17 #include <linux/percpu.h>
18 #include <linux/export.h>
19 #include <linux/seq_file.h>
20 #include <linux/spinlock.h>
21 #include <linux/sysfs.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 
28 const char *perf_pmu_name(void)
29 {
30 	if (cpum_cf_avail() || cpum_sf_avail())
31 		return "CPU-Measurement Facilities (CPU-MF)";
32 	return "pmu";
33 }
34 EXPORT_SYMBOL(perf_pmu_name);
35 
36 int perf_num_counters(void)
37 {
38 	int num = 0;
39 
40 	if (cpum_cf_avail())
41 		num += PERF_CPUM_CF_MAX_CTR;
42 	if (cpum_sf_avail())
43 		num += PERF_CPUM_SF_MAX_CTR;
44 
45 	return num;
46 }
47 EXPORT_SYMBOL(perf_num_counters);
48 
49 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
50 {
51 	struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
52 
53 	if (!stack)
54 		return NULL;
55 
56 	return (struct kvm_s390_sie_block *) stack->empty1[0];
57 }
58 
59 static bool is_in_guest(struct pt_regs *regs)
60 {
61 	if (user_mode(regs))
62 		return false;
63 #if IS_ENABLED(CONFIG_KVM)
64 	return instruction_pointer(regs) == (unsigned long) &sie_exit;
65 #else
66 	return false;
67 #endif
68 }
69 
70 static unsigned long guest_is_user_mode(struct pt_regs *regs)
71 {
72 	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
73 }
74 
75 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
76 {
77 	return sie_block(regs)->gpsw.addr;
78 }
79 
80 unsigned long perf_instruction_pointer(struct pt_regs *regs)
81 {
82 	return is_in_guest(regs) ? instruction_pointer_guest(regs)
83 				 : instruction_pointer(regs);
84 }
85 
86 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
87 {
88 	return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
89 					: PERF_RECORD_MISC_GUEST_KERNEL;
90 }
91 
92 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
93 {
94 	struct perf_sf_sde_regs *sde_regs;
95 	unsigned long flags;
96 
97 	sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
98 	if (sde_regs->in_guest)
99 		flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
100 					: PERF_RECORD_MISC_GUEST_KERNEL;
101 	else
102 		flags = user_mode(regs) ? PERF_RECORD_MISC_USER
103 					: PERF_RECORD_MISC_KERNEL;
104 	return flags;
105 }
106 
107 unsigned long perf_misc_flags(struct pt_regs *regs)
108 {
109 	/* Check if the cpum_sf PMU has created the pt_regs structure.
110 	 * In this case, perf misc flags can be easily extracted.  Otherwise,
111 	 * do regular checks on the pt_regs content.
112 	 */
113 	if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
114 		if (!regs->gprs[15])
115 			return perf_misc_flags_sf(regs);
116 
117 	if (is_in_guest(regs))
118 		return perf_misc_guest_flags(regs);
119 
120 	return user_mode(regs) ? PERF_RECORD_MISC_USER
121 			       : PERF_RECORD_MISC_KERNEL;
122 }
123 
124 static void print_debug_cf(void)
125 {
126 	struct cpumf_ctr_info cf_info;
127 	int cpu = smp_processor_id();
128 
129 	memset(&cf_info, 0, sizeof(cf_info));
130 	if (!qctri(&cf_info))
131 		pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
132 			cpu, cf_info.cfvn, cf_info.csvn,
133 			cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
134 }
135 
136 static void print_debug_sf(void)
137 {
138 	struct hws_qsi_info_block si;
139 	int cpu = smp_processor_id();
140 
141 	memset(&si, 0, sizeof(si));
142 	if (qsi(&si))
143 		return;
144 
145 	pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
146 		cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
147 		si.cpu_speed);
148 
149 	if (si.as)
150 		pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
151 			" bsdes=%i tear=%016lx dear=%016lx\n", cpu,
152 			si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
153 	if (si.ad)
154 		pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
155 			" dsdes=%i tear=%016lx dear=%016lx\n", cpu,
156 			si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
157 }
158 
159 void perf_event_print_debug(void)
160 {
161 	unsigned long flags;
162 
163 	local_irq_save(flags);
164 	if (cpum_cf_avail())
165 		print_debug_cf();
166 	if (cpum_sf_avail())
167 		print_debug_sf();
168 	local_irq_restore(flags);
169 }
170 
171 /* Service level infrastructure */
172 static void sl_print_counter(struct seq_file *m)
173 {
174 	struct cpumf_ctr_info ci;
175 
176 	memset(&ci, 0, sizeof(ci));
177 	if (qctri(&ci))
178 		return;
179 
180 	seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
181 		   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
182 }
183 
184 static void sl_print_sampling(struct seq_file *m)
185 {
186 	struct hws_qsi_info_block si;
187 
188 	memset(&si, 0, sizeof(si));
189 	if (qsi(&si))
190 		return;
191 
192 	if (!si.as && !si.ad)
193 		return;
194 
195 	seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
196 		   " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
197 		   si.cpu_speed);
198 	if (si.as)
199 		seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
200 			   " sample_size=%u\n", si.bsdes);
201 	if (si.ad)
202 		seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
203 			   " sample_size=%u\n", si.dsdes);
204 }
205 
206 static void service_level_perf_print(struct seq_file *m,
207 				     struct service_level *sl)
208 {
209 	if (cpum_cf_avail())
210 		sl_print_counter(m);
211 	if (cpum_sf_avail())
212 		sl_print_sampling(m);
213 }
214 
215 static struct service_level service_level_perf = {
216 	.seq_print = service_level_perf_print,
217 };
218 
219 static int __init service_level_perf_register(void)
220 {
221 	return register_service_level(&service_level_perf);
222 }
223 arch_initcall(service_level_perf_register);
224 
225 static int __perf_callchain_kernel(void *data, unsigned long address, int reliable)
226 {
227 	struct perf_callchain_entry_ctx *entry = data;
228 
229 	perf_callchain_store(entry, address);
230 	return 0;
231 }
232 
233 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
234 			   struct pt_regs *regs)
235 {
236 	if (user_mode(regs))
237 		return;
238 	dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]);
239 }
240 
241 /* Perf definitions for PMU event attributes in sysfs */
242 ssize_t cpumf_events_sysfs_show(struct device *dev,
243 				struct device_attribute *attr, char *page)
244 {
245 	struct perf_pmu_events_attr *pmu_attr;
246 
247 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
248 	return sprintf(page, "event=0x%04llx,name=%s\n",
249 		       pmu_attr->id, attr->attr.name);
250 }
251