linux/arch/sparc/kernel/pcr.c

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/* pcr.c: Generic sparc64 performance counter infrastructure.
*
* Copyright (C) 2009 David S. Miller (davem@davemloft.net)
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/pil.h>
#include <asm/pcr.h>
/* This code is shared between various users of the performance
* counters. Users will be oprofile, pseudo-NMI watchdog, and the
* perf_counter support layer.
*/
/* Performance counter interrupts run unmasked at PIL level 15.
* Therefore we can't do things like wakeups and other work
* that expects IRQ disabling to be adhered to in locking etc.
*
* Therefore in such situations we defer the work by signalling
* a lower level cpu IRQ.
*/
void deferred_pcr_work_irq(int irq, struct pt_regs *regs)
{
clear_softint(1 << PIL_DEFERRED_PCR_WORK);
}
void schedule_deferred_pcr_work(void)
{
set_softint(1 << PIL_DEFERRED_PCR_WORK);
}
const struct pcr_ops *pcr_ops;
EXPORT_SYMBOL_GPL(pcr_ops);
static u64 direct_pcr_read(void)
{
u64 val;
read_pcr(val);
return val;
}
static void direct_pcr_write(u64 val)
{
write_pcr(val);
}
static const struct pcr_ops direct_pcr_ops = {
.read = direct_pcr_read,
.write = direct_pcr_write,
};
static void n2_pcr_write(u64 val)
{
unsigned long ret;
ret = sun4v_niagara2_setperf(HV_N2_PERF_SPARC_CTL, val);
if (val != HV_EOK)
write_pcr(val);
}
static const struct pcr_ops n2_pcr_ops = {
.read = direct_pcr_read,
.write = n2_pcr_write,
};
static unsigned long perf_hsvc_group;
static unsigned long perf_hsvc_major;
static unsigned long perf_hsvc_minor;
static int __init register_perf_hsvc(void)
{
if (tlb_type == hypervisor) {
switch (sun4v_chip_type) {
case SUN4V_CHIP_NIAGARA1:
perf_hsvc_group = HV_GRP_NIAG_PERF;
break;
case SUN4V_CHIP_NIAGARA2:
perf_hsvc_group = HV_GRP_N2_CPU;
break;
default:
return -ENODEV;
}
perf_hsvc_major = 1;
perf_hsvc_minor = 0;
if (sun4v_hvapi_register(perf_hsvc_group,
perf_hsvc_major,
&perf_hsvc_minor)) {
printk("perfmon: Could not register hvapi.\n");
return -ENODEV;
}
}
return 0;
}
static void __init unregister_perf_hsvc(void)
{
if (tlb_type != hypervisor)
return;
sun4v_hvapi_unregister(perf_hsvc_group);
}
int __init pcr_arch_init(void)
{
int err = register_perf_hsvc();
if (err)
return err;
switch (tlb_type) {
case hypervisor:
pcr_ops = &n2_pcr_ops;
break;
case spitfire:
case cheetah:
case cheetah_plus:
pcr_ops = &direct_pcr_ops;
break;
default:
err = -ENODEV;
goto out_unregister;
}
return 0;
out_unregister:
unregister_perf_hsvc();
return err;
}
arch_initcall(pcr_arch_init);