Initial import

1 files changed, 324 insertions, 0 deletions

diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
new file mode 100644
index 000000000..61595c1f0
--- /dev/null
+++ b/arch/s390/kernel/perf_event.c
@@ -0,0 +1,324 @@
+/*
+ * Performance event support for s390x
+ *
+ *  Copyright IBM Corp. 2012, 2013
+ *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#define KMSG_COMPONENT	"perf"
+#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/kvm_host.h>
+#include <linux/percpu.h>
+#include <linux/export.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+#include <asm/irq.h>
+#include <asm/cpu_mf.h>
+#include <asm/lowcore.h>
+#include <asm/processor.h>
+#include <asm/sysinfo.h>
+
+const char *perf_pmu_name(void)
+{
+	if (cpum_cf_avail() || cpum_sf_avail())
+		return "CPU-Measurement Facilities (CPU-MF)";
+	return "pmu";
+}
+EXPORT_SYMBOL(perf_pmu_name);
+
+int perf_num_counters(void)
+{
+	int num = 0;
+
+	if (cpum_cf_avail())
+		num += PERF_CPUM_CF_MAX_CTR;
+	if (cpum_sf_avail())
+		num += PERF_CPUM_SF_MAX_CTR;
+
+	return num;
+}
+EXPORT_SYMBOL(perf_num_counters);
+
+static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
+{
+	struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
+
+	if (!stack)
+		return NULL;
+
+	return (struct kvm_s390_sie_block *) stack->empty1[0];
+}
+
+static bool is_in_guest(struct pt_regs *regs)
+{
+	if (user_mode(regs))
+		return false;
+#if IS_ENABLED(CONFIG_KVM)
+	return instruction_pointer(regs) == (unsigned long) &sie_exit;
+#else
+	return false;
+#endif
+}
+
+static unsigned long guest_is_user_mode(struct pt_regs *regs)
+{
+	return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
+}
+
+static unsigned long instruction_pointer_guest(struct pt_regs *regs)
+{
+	return sie_block(regs)->gpsw.addr & PSW_ADDR_INSN;
+}
+
+unsigned long perf_instruction_pointer(struct pt_regs *regs)
+{
+	return is_in_guest(regs) ? instruction_pointer_guest(regs)
+				 : instruction_pointer(regs);
+}
+
+static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
+{
+	return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
+					: PERF_RECORD_MISC_GUEST_KERNEL;
+}
+
+static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
+{
+	struct perf_sf_sde_regs *sde_regs;
+	unsigned long flags;
+
+	sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
+	if (sde_regs->in_guest)
+		flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
+					: PERF_RECORD_MISC_GUEST_KERNEL;
+	else
+		flags = user_mode(regs) ? PERF_RECORD_MISC_USER
+					: PERF_RECORD_MISC_KERNEL;
+	return flags;
+}
+
+unsigned long perf_misc_flags(struct pt_regs *regs)
+{
+	/* Check if the cpum_sf PMU has created the pt_regs structure.
+	 * In this case, perf misc flags can be easily extracted.  Otherwise,
+	 * do regular checks on the pt_regs content.
+	 */
+	if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
+		if (!regs->gprs[15])
+			return perf_misc_flags_sf(regs);
+
+	if (is_in_guest(regs))
+		return perf_misc_guest_flags(regs);
+
+	return user_mode(regs) ? PERF_RECORD_MISC_USER
+			       : PERF_RECORD_MISC_KERNEL;
+}
+
+static void print_debug_cf(void)
+{
+	struct cpumf_ctr_info cf_info;
+	int cpu = smp_processor_id();
+
+	memset(&cf_info, 0, sizeof(cf_info));
+	if (!qctri(&cf_info))
+		pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
+			cpu, cf_info.cfvn, cf_info.csvn,
+			cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
+}
+
+static void print_debug_sf(void)
+{
+	struct hws_qsi_info_block si;
+	int cpu = smp_processor_id();
+
+	memset(&si, 0, sizeof(si));
+	if (qsi(&si))
+		return;
+
+	pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
+		cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
+		si.cpu_speed);
+
+	if (si.as)
+		pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
+			" bsdes=%i tear=%016lx dear=%016lx\n", cpu,
+			si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
+	if (si.ad)
+		pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
+			" dsdes=%i tear=%016lx dear=%016lx\n", cpu,
+			si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
+}
+
+void perf_event_print_debug(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (cpum_cf_avail())
+		print_debug_cf();
+	if (cpum_sf_avail())
+		print_debug_sf();
+	local_irq_restore(flags);
+}
+
+/* Service level infrastructure */
+static void sl_print_counter(struct seq_file *m)
+{
+	struct cpumf_ctr_info ci;
+
+	memset(&ci, 0, sizeof(ci));
+	if (qctri(&ci))
+		return;
+
+	seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
+		   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
+}
+
+static void sl_print_sampling(struct seq_file *m)
+{
+	struct hws_qsi_info_block si;
+
+	memset(&si, 0, sizeof(si));
+	if (qsi(&si))
+		return;
+
+	if (!si.as && !si.ad)
+		return;
+
+	seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
+		   " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
+		   si.cpu_speed);
+	if (si.as)
+		seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
+			   " sample_size=%u\n", si.bsdes);
+	if (si.ad)
+		seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
+			   " sample_size=%u\n", si.dsdes);
+}
+
+static void service_level_perf_print(struct seq_file *m,
+				     struct service_level *sl)
+{
+	if (cpum_cf_avail())
+		sl_print_counter(m);
+	if (cpum_sf_avail())
+		sl_print_sampling(m);
+}
+
+static struct service_level service_level_perf = {
+	.seq_print = service_level_perf_print,
+};
+
+static int __init service_level_perf_register(void)
+{
+	return register_service_level(&service_level_perf);
+}
+arch_initcall(service_level_perf_register);
+
+/* See also arch/s390/kernel/traps.c */
+static unsigned long __store_trace(struct perf_callchain_entry *entry,
+				   unsigned long sp,
+				   unsigned long low, unsigned long high)
+{
+	struct stack_frame *sf;
+	struct pt_regs *regs;
+
+	while (1) {
+		sp = sp & PSW_ADDR_INSN;
+		if (sp < low || sp > high - sizeof(*sf))
+			return sp;
+		sf = (struct stack_frame *) sp;
+		perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
+		/* Follow the backchain. */
+		while (1) {
+			low = sp;
+			sp = sf->back_chain & PSW_ADDR_INSN;
+			if (!sp)
+				break;
+			if (sp <= low || sp > high - sizeof(*sf))
+				return sp;
+			sf = (struct stack_frame *) sp;
+			perf_callchain_store(entry,
+					     sf->gprs[8] & PSW_ADDR_INSN);
+		}
+		/* Zero backchain detected, check for interrupt frame. */
+		sp = (unsigned long) (sf + 1);
+		if (sp <= low || sp > high - sizeof(*regs))
+			return sp;
+		regs = (struct pt_regs *) sp;
+		perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN);
+		low = sp;
+		sp = regs->gprs[15];
+	}
+}
+
+void perf_callchain_kernel(struct perf_callchain_entry *entry,
+			   struct pt_regs *regs)
+{
+	unsigned long head;
+	struct stack_frame *head_sf;
+
+	if (user_mode(regs))
+		return;
+
+	head = regs->gprs[15];
+	head_sf = (struct stack_frame *) head;
+
+	if (!head_sf || !head_sf->back_chain)
+		return;
+
+	head = head_sf->back_chain;
+	head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE,
+			     S390_lowcore.async_stack);
+
+	__store_trace(entry, head, S390_lowcore.thread_info,
+		      S390_lowcore.thread_info + THREAD_SIZE);
+}
+
+/* Perf defintions for PMU event attributes in sysfs */
+ssize_t cpumf_events_sysfs_show(struct device *dev,
+				struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+	return sprintf(page, "event=0x%04llx,name=%s\n",
+		       pmu_attr->id, attr->attr.name);
+}
+
+/* Reserve/release functions for sharing perf hardware */
+static DEFINE_SPINLOCK(perf_hw_owner_lock);
+static void *perf_sampling_owner;
+
+int perf_reserve_sampling(void)
+{
+	int err;
+
+	err = 0;
+	spin_lock(&perf_hw_owner_lock);
+	if (perf_sampling_owner) {
+		pr_warn("The sampling facility is already reserved by %p\n",
+			perf_sampling_owner);
+		err = -EBUSY;
+	} else
+		perf_sampling_owner = __builtin_return_address(0);
+	spin_unlock(&perf_hw_owner_lock);
+	return err;
+}
+EXPORT_SYMBOL(perf_reserve_sampling);
+
+void perf_release_sampling(void)
+{
+	spin_lock(&perf_hw_owner_lock);
+	WARN_ON(!perf_sampling_owner);
+	perf_sampling_owner = NULL;
+	spin_unlock(&perf_hw_owner_lock);
+}
+EXPORT_SYMBOL(perf_release_sampling);