You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
88 lines
1.9 KiB
88 lines
1.9 KiB
/*
|
|
* linux/arch/ppc64/kernel/pmc.c
|
|
*
|
|
* Copyright (C) 2004 David Gibson, IBM Corporation.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/pmc.h>
|
|
|
|
/* Ensure exceptions are disabled */
|
|
static void dummy_perf(struct pt_regs *regs)
|
|
{
|
|
unsigned int mmcr0 = mfspr(SPRN_MMCR0);
|
|
|
|
mmcr0 &= ~(MMCR0_PMXE|MMCR0_PMAO);
|
|
mtspr(SPRN_MMCR0, mmcr0);
|
|
}
|
|
|
|
static spinlock_t pmc_owner_lock = SPIN_LOCK_UNLOCKED;
|
|
static void *pmc_owner_caller; /* mostly for debugging */
|
|
perf_irq_t perf_irq = dummy_perf;
|
|
|
|
int reserve_pmc_hardware(perf_irq_t new_perf_irq)
|
|
{
|
|
int err = 0;
|
|
|
|
spin_lock(&pmc_owner_lock);
|
|
|
|
if (pmc_owner_caller) {
|
|
printk(KERN_WARNING "reserve_pmc_hardware: "
|
|
"PMC hardware busy (reserved by caller %p)\n",
|
|
pmc_owner_caller);
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
pmc_owner_caller = __builtin_return_address(0);
|
|
perf_irq = new_perf_irq ? : dummy_perf;
|
|
|
|
out:
|
|
spin_unlock(&pmc_owner_lock);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
|
|
|
|
void release_pmc_hardware(void)
|
|
{
|
|
spin_lock(&pmc_owner_lock);
|
|
|
|
WARN_ON(! pmc_owner_caller);
|
|
|
|
pmc_owner_caller = NULL;
|
|
perf_irq = dummy_perf;
|
|
|
|
spin_unlock(&pmc_owner_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(release_pmc_hardware);
|
|
|
|
void power4_enable_pmcs(void)
|
|
{
|
|
unsigned long hid0;
|
|
|
|
hid0 = mfspr(HID0);
|
|
hid0 |= 1UL << (63 - 20);
|
|
|
|
/* POWER4 requires the following sequence */
|
|
asm volatile(
|
|
"sync\n"
|
|
"mtspr %1, %0\n"
|
|
"mfspr %0, %1\n"
|
|
"mfspr %0, %1\n"
|
|
"mfspr %0, %1\n"
|
|
"mfspr %0, %1\n"
|
|
"mfspr %0, %1\n"
|
|
"mfspr %0, %1\n"
|
|
"isync" : "=&r" (hid0) : "i" (HID0), "0" (hid0):
|
|
"memory");
|
|
}
|
|
|