/*
* Performance event support for s390x
*
* Copyright IBM Corp. 2012
* 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 <asm/irq.h>
#include <asm/cpu_mf.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
const char *perf_pmu_name(void)
{
if (cpum_cf_avail() || cpum_sf_avail())
return "CPU-measurement facilities (CPUMF)";
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;
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 defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
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;
}
unsigned long perf_misc_flags(struct pt_regs *regs)
{
if (is_in_guest(regs))
return perf_misc_guest_flags(regs);
return user_mode(regs) ? PERF_RECORD_MISC_USER
: PERF_RECORD_MISC_KERNEL;
}
void perf_event_print_debug(void)
{
struct cpumf_ctr_info cf_info;
unsigned long flags;
int cpu;
if (!cpum_cf_avail())
return;
local_irq_save(flags);
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);
local_irq_restore(flags);
}
/* 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);
}
