path: root/arch/s390/oprofile/hwsampler.c

/*
 * Copyright IBM Corp. 2010
 * Author: Heinz Graalfs <graalfs@de.ibm.com>
 */

#include <linux/kernel_stat.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/semaphore.h>
#include <linux/oom.h>
#include <linux/oprofile.h>

#include <asm/facility.h>
#include <asm/cpu_mf.h>
#include <asm/irq.h>

#include "hwsampler.h"
#include "op_counter.h"

#define MAX_NUM_SDB 511
#define MIN_NUM_SDB 1

DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);

struct hws_execute_parms {
	void *buffer;
	signed int rc;
};

DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);

static DEFINE_MUTEX(hws_sem);
static DEFINE_MUTEX(hws_sem_oom);

static unsigned char hws_flush_all;
static unsigned int hws_oom;
static unsigned int hws_alert;
static struct workqueue_struct *hws_wq;

static unsigned int hws_state;
enum {
	HWS_INIT = 1,
	HWS_DEALLOCATED,
	HWS_STOPPED,
	HWS_STARTED,
	HWS_STOPPING };

/* set to 1 if called by kernel during memory allocation */
static unsigned char oom_killer_was_active;
/* size of SDBT and SDB as of allocate API */
static unsigned long num_sdbt = 100;
static unsigned long num_sdb = 511;
/* sampling interval (machine cycles) */
static unsigned long interval;

static unsigned long min_sampler_rate;
static unsigned long max_sampler_rate;

static void execute_qsi(void *parms)
{
	struct hws_execute_parms *ep = parms;

	ep->rc = qsi(ep->buffer);
}

static void execute_ssctl(void *parms)
{
	struct hws_execute_parms *ep = parms;

	ep->rc = lsctl(ep->buffer);
}

static int smp_ctl_ssctl_stop(int cpu)
{
	int rc;
	struct hws_execute_parms ep;
	struct hws_cpu_buffer *cb;

	cb = &per_cpu(sampler_cpu_buffer, cpu);

	cb->ssctl.es = 0;
	cb->ssctl.cs = 0;

	ep.buffer = &cb->ssctl;
	smp_call_function_single(cpu, execute_ssctl, &ep, 1);
	rc = ep.rc;
	if (rc) {
		printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
		dump_stack();
	}

	ep.buffer = &cb->qsi;
	smp_call_function_single(cpu, execute_qsi, &ep, 1);

	if (cb->qsi.es || cb->qsi.cs) {
		printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
		dump_stack();
	}

	return rc;
}

static int smp_ctl_ssctl_deactivate(int cpu)
{
	int rc;
	struct hws_execute_parms ep;
	struct hws_cpu_buffer *cb;

	cb = &per_cpu(sampler_cpu_buffer, cpu);

	cb->ssctl.es = 1;
	cb->ssctl.cs = 0;

	ep.buffer = &cb->ssctl;
	smp_call_function_single(cpu, execute_ssctl, &ep, 1);
	rc = ep.rc;
	if (rc)
		printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu