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Commit 47a486cc authored by Cyrill Gorcunov's avatar Cyrill Gorcunov Committed by Ingo Molnar
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x86: perfctr-watchdog.c - coding style cleanup 

Just some code beautification. Nothing else.
Signed-off-by: default avatarCyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2bc0d261
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Showing with 112 additions and 90 deletions
arch/x86/kernel/cpu/perfctr-watchdog.c
View file @ 47a486cc
/* local apic based NMI watchdog for various CPUs.
This file also handles reservation of performance counters for coordination
with other users (like oprofile).
Note that these events normally don't tick when the CPU idles. This means
the frequency varies with CPU load.
Original code for K7/P6 written by Keith Owens */
/*
* local apic based NMI watchdog for various CPUs.
*
* This file also handles reservation of performance counters for coordination
* with other users (like oprofile).
*
* Note that these events normally don't tick when the CPU idles. This means
* the frequency varies with CPU load.
*
* Original code for K7/P6 written by Keith Owens
*
*/
#include <linux/percpu.h>
#include <linux/module.h>
......@@ -36,12 +40,16 @@ struct wd_ops {
static const struct wd_ops *wd_ops;
/* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's
* offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now)
/*
* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's
* offset from MSR_P4_BSU_ESCR0.
*
* It will be the max for all platforms (for now)
*/
#define NMI_MAX_COUNTER_BITS 66
/* perfctr_nmi_owner tracks the ownership of the perfctr registers:
/*
* perfctr_nmi_owner tracks the ownership of the perfctr registers:
* evtsel_nmi_owner tracks the ownership of the event selection
* - different performance counters/ event selection may be reserved for
* different subsystems this reservation system just tries to coordinate
......@@ -73,8 +81,10 @@ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
return 0;
}
/* converts an msr to an appropriate reservation bit */
/* returns the bit offset of the event selection register */
/*
* converts an msr to an appropriate reservation bit
* returns the bit offset of the event selection register
*/
static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
{
/* returns the bit offset of the event selection register */
......@@ -114,6 +124,7 @@ int avail_to_resrv_perfctr_nmi(unsigned int msr)
return (!test_bit(counter, perfctr_nmi_owner));
}
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit);
int reserve_perfctr_nmi(unsigned int msr)
{
......@@ -128,6 +139,7 @@ int reserve_perfctr_nmi(unsigned int msr)
return 1;
return 0;
}
EXPORT_SYMBOL(reserve_perfctr_nmi);
void release_perfctr_nmi(unsigned int msr)
{
......@@ -140,6 +152,7 @@ void release_perfctr_nmi(unsigned int msr)
clear_bit(counter, perfctr_nmi_owner);
}
EXPORT_SYMBOL(release_perfctr_nmi);
int reserve_evntsel_nmi(unsigned int msr)
{
......@@ -154,6 +167,7 @@ int reserve_evntsel_nmi(unsigned int msr)
return 1;
return 0;
}
EXPORT_SYMBOL(reserve_evntsel_nmi);
void release_evntsel_nmi(unsigned int msr)
{
......@@ -166,11 +180,6 @@ void release_evntsel_nmi(unsigned int msr)
clear_bit(counter, evntsel_nmi_owner);
}
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit);
EXPORT_SYMBOL(reserve_perfctr_nmi);
EXPORT_SYMBOL(release_perfctr_nmi);
EXPORT_SYMBOL(reserve_evntsel_nmi);
EXPORT_SYMBOL(release_evntsel_nmi);
void disable_lapic_nmi_watchdog(void)
......@@ -234,8 +243,8 @@ static unsigned int adjust_for_32bit_ctr(unsigned int hz)
return retval;
}
static void
write_watchdog_counter(unsigned int perfctr_msr, const char *descr, unsigned nmi_hz)
static void write_watchdog_counter(unsigned int perfctr_msr,
const char *descr, unsigned nmi_hz)
{
u64 count = (u64)cpu_khz * 1000;
......@@ -256,9 +265,10 @@ static void write_watchdog_counter32(unsigned int perfctr_msr,
wrmsr(perfctr_msr, (u32)(-count), 0);
}
/* AMD K7/K8/Family10h/Family11h support. AMD keeps this interface
nicely stable so there is not much variety */
/*
* AMD K7/K8/Family10h/Family11h support.
* AMD keeps this interface nicely stable so there is not much variety
*/
#define K7_EVNTSEL_ENABLE (1 << 22)
#define K7_EVNTSEL_INT (1 << 20)
#define K7_EVNTSEL_OS (1 << 17)
......@@ -291,7 +301,7 @@ static int setup_k7_watchdog(unsigned nmi_hz)
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->cccr_msr = 0; /* unused */
return 1;
}
......@@ -334,11 +344,12 @@ static const struct wd_ops k7_wd_ops = {
.stop = single_msr_stop_watchdog,
.perfctr = MSR_K7_PERFCTR0,
.evntsel = MSR_K7_EVNTSEL0,
.checkbit = 1ULL<<47,
.checkbit = 1ULL << 47,
};
/* Intel Model 6 (PPro+,P2,P3,P-M,Core1) */
/*
* Intel Model 6 (PPro+,P2,P3,P-M,Core1)
*/
#define P6_EVNTSEL0_ENABLE (1 << 22)
#define P6_EVNTSEL_INT (1 << 20)
#define P6_EVNTSEL_OS (1 << 17)
......@@ -374,17 +385,20 @@ static int setup_p6_watchdog(unsigned nmi_hz)
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->cccr_msr = 0; /* unused */
return 1;
}
static void p6_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
{
/* P6 based Pentium M need to re-unmask
/*
* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
* other P6 variant.
* ArchPerfom/Core Duo also needs this */
* ArchPerfom/Core Duo also needs this
*/
apic_write(APIC_LVTPC, APIC_DM_NMI);
/* P6/ARCH_PERFMON has 32 bit counter write */
write_watchdog_counter32(wd->perfctr_msr, NULL,nmi_hz);
}
......@@ -397,29 +411,32 @@ static const struct wd_ops p6_wd_ops = {
.stop = single_msr_stop_watchdog,
.perfctr = MSR_P6_PERFCTR0,
.evntsel = MSR_P6_EVNTSEL0,
.checkbit = 1ULL<<39,
.checkbit = 1ULL << 39,
};
/* Intel P4 performance counters. By far the most complicated of all. */
#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7)
#define P4_ESCR_EVENT_SELECT(N) ((N)<<25)
#define P4_ESCR_OS (1<<3)
#define P4_ESCR_USR (1<<2)
#define P4_CCCR_OVF_PMI0 (1<<26)
#define P4_CCCR_OVF_PMI1 (1<<27)
#define P4_CCCR_THRESHOLD(N) ((N)<<20)
#define P4_CCCR_COMPLEMENT (1<<19)
#define P4_CCCR_COMPARE (1<<18)
#define P4_CCCR_REQUIRED (3<<16)
#define P4_CCCR_ESCR_SELECT(N) ((N)<<13)
#define P4_CCCR_ENABLE (1<<12)
#define P4_CCCR_OVF (1<<31)
/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
CRU_ESCR0 (with any non-null event selector) through a complemented
max threshold. [IA32-Vol3, Section 14.9.9] */
/*
* Intel P4 performance counters.
* By far the most complicated of all.
*/
#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1 << 7)
#define P4_ESCR_EVENT_SELECT(N) ((N) << 25)
#define P4_ESCR_OS (1 << 3)
#define P4_ESCR_USR (1 << 2)
#define P4_CCCR_OVF_PMI0 (1 << 26)
#define P4_CCCR_OVF_PMI1 (1 << 27)
#define P4_CCCR_THRESHOLD(N) ((N) << 20)
#define P4_CCCR_COMPLEMENT (1 << 19)
#define P4_CCCR_COMPARE (1 << 18)
#define P4_CCCR_REQUIRED (3 << 16)
#define P4_CCCR_ESCR_SELECT(N) ((N) << 13)
#define P4_CCCR_ENABLE (1 << 12)
#define P4_CCCR_OVF (1 << 31)
/*
* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
* CRU_ESCR0 (with any non-null event selector) through a complemented
* max threshold. [IA32-Vol3, Section 14.9.9]
*/
static int setup_p4_watchdog(unsigned nmi_hz)
{
unsigned int perfctr_msr, evntsel_msr, cccr_msr;
......@@ -444,7 +461,8 @@ static int setup_p4_watchdog(unsigned nmi_hz)
#endif
ht_num = 0;
/* performance counters are shared resources
/*
* performance counters are shared resources
* assign each hyperthread its own set
* (re-use the ESCR0 register, seems safe
* and keeps the cccr_val the same)
......@@ -550,12 +568,13 @@ static const struct wd_ops p4_wd_ops = {
/* RED-PEN this is wrong for the other sibling */
.perfctr = MSR_P4_BPU_PERFCTR0,
.evntsel = MSR_P4_BSU_ESCR0,
.checkbit = 1ULL<<39,
.checkbit = 1ULL << 39,
};
/* Watchdog using the Intel architected PerfMon. Used for Core2 and hopefully
all future Intel CPUs. */
/*
* Watchdog using the Intel architected PerfMon.
* Used for Core2 and hopefully all future Intel CPUs.
*/
#define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL
#define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK
......@@ -601,7 +620,7 @@ static int setup_intel_arch_watchdog(unsigned nmi_hz)
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->cccr_msr = 0; /* unused */
intel_arch_wd_ops.checkbit = 1ULL << (eax.split.bit_width - 1);
return 1;
}
......@@ -626,8 +645,10 @@ static void probe_nmi_watchdog(void)
wd_ops = &k7_wd_ops;
break;
case X86_VENDOR_INTEL:
/* Work around Core Duo (Yonah) errata AE49 where perfctr1
doesn't have a working enable bit. */
/*
* Work around Core Duo (Yonah) errata AE49 where perfctr1
* doesn't have a working enable bit.
*/
if (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 14) {
intel_arch_wd_ops.perfctr = MSR_ARCH_PERFMON_PERFCTR0;
intel_arch_wd_ops.evntsel = MSR_ARCH_PERFMON_EVENTSEL0;
......@@ -638,7 +659,7 @@ static void probe_nmi_watchdog(void)
}
switch (boot_cpu_data.x86) {
case 6:
if (boot_cpu_data.x86_model > 0xd)
if (boot_cpu_data.x86_model > 13)
return;
wd_ops = &p6_wd_ops;
......@@ -699,10 +720,11 @@ int lapic_wd_event(unsigned nmi_hz)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
u64 ctr;
rdmsrl(wd->perfctr_msr, ctr);
if (ctr & wd_ops->checkbit) { /* perfctr still running? */
if (ctr & wd_ops->checkbit) /* perfctr still running? */
return 0;
}
wd_ops->rearm(wd, nmi_hz);
return 1;
}
......
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