xref: /openbmc/linux/arch/s390/kernel/perf_event.c (revision c4f7ac64)
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 static 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->empty1[0];
34 }
35 
36 static 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 
47 static unsigned long guest_is_user_mode(struct pt_regs *regs)
48 {
49 	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
50 }
51 
52 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
53 {
54 	return sie_block(regs)->gpsw.addr;
55 }
56 
57 unsigned long perf_instruction_pointer(struct pt_regs *regs)
58 {
59 	return is_in_guest(regs) ? instruction_pointer_guest(regs)
60 				 : instruction_pointer(regs);
61 }
62 
63 static 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 
69 static 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 
84 unsigned long perf_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 
101 static 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 
113 static 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 
136 void 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 */
149 static 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, "CPU-MF: Counter facility: version=%u.%u "
158 		   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
159 }
160 
161 static 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, "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, "CPU-MF: Sampling facility: mode=basic"
177 			   " sample_size=%u\n", si.bsdes);
178 	if (si.ad)
179 		seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
180 			   " sample_size=%u\n", si.dsdes);
181 }
182 
183 static 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 
192 static struct service_level service_level_perf = {
193 	.seq_print = service_level_perf_print,
194 };
195 
196 static int __init service_level_perf_register(void)
197 {
198 	return register_service_level(&service_level_perf);
199 }
200 arch_initcall(service_level_perf_register);
201 
202 void 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);
210 		if (!addr || perf_callchain_store(entry, addr))
211 			return;
212 	}
213 }
214 
215 /* Perf definitions for PMU event attributes in sysfs */
216 ssize_t cpumf_events_sysfs_show(struct device *dev,
217 				struct device_attribute *attr, char *page)
218 {
219 	struct perf_pmu_events_attr *pmu_attr;
220 
221 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
222 	return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
223 }
224