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
 28const 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}
 34EXPORT_SYMBOL(perf_pmu_name);
 35
 36int 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}
 47EXPORT_SYMBOL(perf_num_counters);
 48
 49static 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
 59static 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
 70static unsigned long guest_is_user_mode(struct pt_regs *regs)
 71{
 72	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
 73}
 74
 75static unsigned long instruction_pointer_guest(struct pt_regs *regs)
 76{
 77	return sie_block(regs)->gpsw.addr;
 78}
 79
 80unsigned 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
 86static 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
 92static 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
107unsigned 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
124static 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
136static 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
159void 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 */
172static 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
184static 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
206static 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
215static struct service_level service_level_perf = {
216	.seq_print = service_level_perf_print,
217};
218
219static int __init service_level_perf_register(void)
220{
221	return register_service_level(&service_level_perf);
222}
223arch_initcall(service_level_perf_register);
224
225static int __perf_callchain_kernel(void *data, unsigned long address)
226{
227	struct perf_callchain_entry *entry = data;
228
229	perf_callchain_store(entry, address);
230	return 0;
231}
232
233void perf_callchain_kernel(struct perf_callchain_entry *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 */
242ssize_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
252/* Reserve/release functions for sharing perf hardware */
253static DEFINE_SPINLOCK(perf_hw_owner_lock);
254static void *perf_sampling_owner;
255
256int perf_reserve_sampling(void)
257{
258	int err;
259
260	err = 0;
261	spin_lock(&perf_hw_owner_lock);
262	if (perf_sampling_owner) {
263		pr_warn("The sampling facility is already reserved by %p\n",
264			perf_sampling_owner);
265		err = -EBUSY;
266	} else
267		perf_sampling_owner = __builtin_return_address(0);
268	spin_unlock(&perf_hw_owner_lock);
269	return err;
270}
271EXPORT_SYMBOL(perf_reserve_sampling);
272
273void perf_release_sampling(void)
274{
275	spin_lock(&perf_hw_owner_lock);
276	WARN_ON(!perf_sampling_owner);
277	perf_sampling_owner = NULL;
278	spin_unlock(&perf_hw_owner_lock);
279}
280EXPORT_SYMBOL(perf_release_sampling);