linux/arch/sparc/kernel/pcr.c
David S. Miller c6fee0810d sparc64: Fix build errors with gcc-4.6.0
Most of the warnings emitted (we fail arch/sparc file
builds with -Werror) were legitimate but harmless, however
one case (n2_pcr_write) was a genuine bug.

Based almost entirely upon a patch by Sam Ravnborg.

Reported-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-16 18:19:15 -07:00

170 lines
3.3 KiB
C

/* 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 <linux/irq_work.h>
#include <linux/ftrace.h>
#include <asm/pil.h>
#include <asm/pcr.h>
#include <asm/nmi.h>
/* This code is shared between various users of the performance
* counters. Users will be oprofile, pseudo-NMI watchdog, and the
* perf_event support layer.
*/
#define PCR_SUN4U_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE)
#define PCR_N2_ENABLE (PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE | \
PCR_N2_TOE_OV1 | \
(2 << PCR_N2_SL1_SHIFT) | \
(0xff << PCR_N2_MASK1_SHIFT))
u64 pcr_enable;
unsigned int picl_shift;
/* 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 __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs;
clear_softint(1 << PIL_DEFERRED_PCR_WORK);
old_regs = set_irq_regs(regs);
irq_enter();
#ifdef CONFIG_IRQ_WORK
irq_work_run();
#endif
irq_exit();
set_irq_regs(old_regs);
}
void arch_irq_work_raise(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 (ret != 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;
pcr_enable = PCR_N2_ENABLE;
picl_shift = 2;
break;
case cheetah:
case cheetah_plus:
pcr_ops = &direct_pcr_ops;
pcr_enable = PCR_SUN4U_ENABLE;
break;
case spitfire:
/* UltraSPARC-I/II and derivatives lack a profile
* counter overflow interrupt so we can't make use of
* their hardware currently.
*/
/* fallthrough */
default:
err = -ENODEV;
goto out_unregister;
}
return nmi_init();
out_unregister:
unregister_perf_hsvc();
return err;
}