xref: /openbmc/linux/arch/s390/kernel/perf_event.c (revision e3b9f1e8)
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 
25 const char *perf_pmu_name(void)
26 {
27 	if (cpum_cf_avail() || cpum_sf_avail())
28 		return "CPU-Measurement Facilities (CPU-MF)";
29 	return "pmu";
30 }
31 EXPORT_SYMBOL(perf_pmu_name);
32 
33 int perf_num_counters(void)
34 {
35 	int num = 0;
36 
37 	if (cpum_cf_avail())
38 		num += PERF_CPUM_CF_MAX_CTR;
39 	if (cpum_sf_avail())
40 		num += PERF_CPUM_SF_MAX_CTR;
41 
42 	return num;
43 }
44 EXPORT_SYMBOL(perf_num_counters);
45 
46 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
47 {
48 	struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
49 
50 	if (!stack)
51 		return NULL;
52 
53 	return (struct kvm_s390_sie_block *) stack->empty1[0];
54 }
55 
56 static bool is_in_guest(struct pt_regs *regs)
57 {
58 	if (user_mode(regs))
59 		return false;
60 #if IS_ENABLED(CONFIG_KVM)
61 	return instruction_pointer(regs) == (unsigned long) &sie_exit;
62 #else
63 	return false;
64 #endif
65 }
66 
67 static unsigned long guest_is_user_mode(struct pt_regs *regs)
68 {
69 	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
70 }
71 
72 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
73 {
74 	return sie_block(regs)->gpsw.addr;
75 }
76 
77 unsigned long perf_instruction_pointer(struct pt_regs *regs)
78 {
79 	return is_in_guest(regs) ? instruction_pointer_guest(regs)
80 				 : instruction_pointer(regs);
81 }
82 
83 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
84 {
85 	return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
86 					: PERF_RECORD_MISC_GUEST_KERNEL;
87 }
88 
89 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
90 {
91 	struct perf_sf_sde_regs *sde_regs;
92 	unsigned long flags;
93 
94 	sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
95 	if (sde_regs->in_guest)
96 		flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
97 					: PERF_RECORD_MISC_GUEST_KERNEL;
98 	else
99 		flags = user_mode(regs) ? PERF_RECORD_MISC_USER
100 					: PERF_RECORD_MISC_KERNEL;
101 	return flags;
102 }
103 
104 unsigned long perf_misc_flags(struct pt_regs *regs)
105 {
106 	/* Check if the cpum_sf PMU has created the pt_regs structure.
107 	 * In this case, perf misc flags can be easily extracted.  Otherwise,
108 	 * do regular checks on the pt_regs content.
109 	 */
110 	if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
111 		if (!regs->gprs[15])
112 			return perf_misc_flags_sf(regs);
113 
114 	if (is_in_guest(regs))
115 		return perf_misc_guest_flags(regs);
116 
117 	return user_mode(regs) ? PERF_RECORD_MISC_USER
118 			       : PERF_RECORD_MISC_KERNEL;
119 }
120 
121 static void print_debug_cf(void)
122 {
123 	struct cpumf_ctr_info cf_info;
124 	int cpu = smp_processor_id();
125 
126 	memset(&cf_info, 0, sizeof(cf_info));
127 	if (!qctri(&cf_info))
128 		pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
129 			cpu, cf_info.cfvn, cf_info.csvn,
130 			cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
131 }
132 
133 static void print_debug_sf(void)
134 {
135 	struct hws_qsi_info_block si;
136 	int cpu = smp_processor_id();
137 
138 	memset(&si, 0, sizeof(si));
139 	if (qsi(&si))
140 		return;
141 
142 	pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
143 		cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
144 		si.cpu_speed);
145 
146 	if (si.as)
147 		pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
148 			" bsdes=%i tear=%016lx dear=%016lx\n", cpu,
149 			si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
150 	if (si.ad)
151 		pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
152 			" dsdes=%i tear=%016lx dear=%016lx\n", cpu,
153 			si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
154 }
155 
156 void perf_event_print_debug(void)
157 {
158 	unsigned long flags;
159 
160 	local_irq_save(flags);
161 	if (cpum_cf_avail())
162 		print_debug_cf();
163 	if (cpum_sf_avail())
164 		print_debug_sf();
165 	local_irq_restore(flags);
166 }
167 
168 /* Service level infrastructure */
169 static void sl_print_counter(struct seq_file *m)
170 {
171 	struct cpumf_ctr_info ci;
172 
173 	memset(&ci, 0, sizeof(ci));
174 	if (qctri(&ci))
175 		return;
176 
177 	seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
178 		   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
179 }
180 
181 static void sl_print_sampling(struct seq_file *m)
182 {
183 	struct hws_qsi_info_block si;
184 
185 	memset(&si, 0, sizeof(si));
186 	if (qsi(&si))
187 		return;
188 
189 	if (!si.as && !si.ad)
190 		return;
191 
192 	seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
193 		   " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
194 		   si.cpu_speed);
195 	if (si.as)
196 		seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
197 			   " sample_size=%u\n", si.bsdes);
198 	if (si.ad)
199 		seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
200 			   " sample_size=%u\n", si.dsdes);
201 }
202 
203 static void service_level_perf_print(struct seq_file *m,
204 				     struct service_level *sl)
205 {
206 	if (cpum_cf_avail())
207 		sl_print_counter(m);
208 	if (cpum_sf_avail())
209 		sl_print_sampling(m);
210 }
211 
212 static struct service_level service_level_perf = {
213 	.seq_print = service_level_perf_print,
214 };
215 
216 static int __init service_level_perf_register(void)
217 {
218 	return register_service_level(&service_level_perf);
219 }
220 arch_initcall(service_level_perf_register);
221 
222 static int __perf_callchain_kernel(void *data, unsigned long address, int reliable)
223 {
224 	struct perf_callchain_entry_ctx *entry = data;
225 
226 	perf_callchain_store(entry, address);
227 	return 0;
228 }
229 
230 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
231 			   struct pt_regs *regs)
232 {
233 	if (user_mode(regs))
234 		return;
235 	dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]);
236 }
237 
238 /* Perf definitions for PMU event attributes in sysfs */
239 ssize_t cpumf_events_sysfs_show(struct device *dev,
240 				struct device_attribute *attr, char *page)
241 {
242 	struct perf_pmu_events_attr *pmu_attr;
243 
244 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
245 	return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
246 }
247