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linux/arch/x86/oprofile/op_model_ppro.c
Andi Kleen b991702884 oprofile: Implement Intel architectural perfmon support
Newer Intel CPUs (Core1+) have support for architectural
events described in CPUID 0xA. See the IA32 SDM Vol3b.18 for details.

The advantage of this is that it can be done without knowing about
the specific CPU, because the CPU describes by itself what
performance events are supported. This is only a fallback
because only a limited set of 6 events are supported.
This allows to do profiling on Nehalem and on Atom systems
(later not tested)

This patch implements support for that in oprofile's Intel
Family 6 profiling module. It also has the advantage of supporting
an arbitary number of events now as reported by the CPU.
Also allow arbitary counter widths >32bit while we're at it.

Requires a patched oprofile userland to support the new
architecture.

v2: update for latest oprofile tree
    remove force_arch_perfmon

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-13 19:25:09 +02:00

253 lines
6.4 KiB
C

/*
* @file op_model_ppro.h
* Family 6 perfmon and architectural perfmon MSR operations
*
* @remark Copyright 2002 OProfile authors
* @remark Copyright 2008 Intel Corporation
* @remark Read the file COPYING
*
* @author John Levon
* @author Philippe Elie
* @author Graydon Hoare
* @author Andi Kleen
*/
#include <linux/oprofile.h>
#include <linux/slab.h>
#include <asm/ptrace.h>
#include <asm/msr.h>
#include <asm/apic.h>
#include <asm/nmi.h>
#include <asm/intel_arch_perfmon.h>
#include "op_x86_model.h"
#include "op_counter.h"
static int num_counters = 2;
static int counter_width = 32;
#define CTR_IS_RESERVED(msrs, c) (msrs->counters[(c)].addr ? 1 : 0)
#define CTR_READ(l, h, msrs, c) do {rdmsr(msrs->counters[(c)].addr, (l), (h)); } while (0)
#define CTR_OVERFLOWED(n) (!((n) & (1U<<(counter_width-1))))
#define CTRL_IS_RESERVED(msrs, c) (msrs->controls[(c)].addr ? 1 : 0)
#define CTRL_READ(l, h, msrs, c) do {rdmsr((msrs->controls[(c)].addr), (l), (h)); } while (0)
#define CTRL_WRITE(l, h, msrs, c) do {wrmsr((msrs->controls[(c)].addr), (l), (h)); } while (0)
#define CTRL_SET_ACTIVE(n) (n |= (1<<22))
#define CTRL_SET_INACTIVE(n) (n &= ~(1<<22))
#define CTRL_CLEAR(x) (x &= (1<<21))
#define CTRL_SET_ENABLE(val) (val |= 1<<20)
#define CTRL_SET_USR(val, u) (val |= ((u & 1) << 16))
#define CTRL_SET_KERN(val, k) (val |= ((k & 1) << 17))
#define CTRL_SET_UM(val, m) (val |= (m << 8))
#define CTRL_SET_EVENT(val, e) (val |= e)
static u64 *reset_value;
static void ppro_fill_in_addresses(struct op_msrs * const msrs)
{
int i;
for (i = 0; i < num_counters; i++) {
if (reserve_perfctr_nmi(MSR_P6_PERFCTR0 + i))
msrs->counters[i].addr = MSR_P6_PERFCTR0 + i;
else
msrs->counters[i].addr = 0;
}
for (i = 0; i < num_counters; i++) {
if (reserve_evntsel_nmi(MSR_P6_EVNTSEL0 + i))
msrs->controls[i].addr = MSR_P6_EVNTSEL0 + i;
else
msrs->controls[i].addr = 0;
}
}
static void ppro_setup_ctrs(struct op_msrs const * const msrs)
{
unsigned int low, high;
int i;
if (!reset_value) {
reset_value = kmalloc(sizeof(unsigned) * num_counters,
GFP_ATOMIC);
if (!reset_value)
return;
}
if (cpu_has_arch_perfmon) {
union cpuid10_eax eax;
eax.full = cpuid_eax(0xa);
if (counter_width < eax.split.bit_width)
counter_width = eax.split.bit_width;
}
/* clear all counters */
for (i = 0 ; i < num_counters; ++i) {
if (unlikely(!CTRL_IS_RESERVED(msrs, i)))
continue;
CTRL_READ(low, high, msrs, i);
CTRL_CLEAR(low);
CTRL_WRITE(low, high, msrs, i);
}
/* avoid a false detection of ctr overflows in NMI handler */
for (i = 0; i < num_counters; ++i) {
if (unlikely(!CTR_IS_RESERVED(msrs, i)))
continue;
wrmsrl(msrs->counters[i].addr, -1LL);
}
/* enable active counters */
for (i = 0; i < num_counters; ++i) {
if ((counter_config[i].enabled) && (CTR_IS_RESERVED(msrs, i))) {
reset_value[i] = counter_config[i].count;
wrmsrl(msrs->counters[i].addr, -reset_value[i]);
CTRL_READ(low, high, msrs, i);
CTRL_CLEAR(low);
CTRL_SET_ENABLE(low);
CTRL_SET_USR(low, counter_config[i].user);
CTRL_SET_KERN(low, counter_config[i].kernel);
CTRL_SET_UM(low, counter_config[i].unit_mask);
CTRL_SET_EVENT(low, counter_config[i].event);
CTRL_WRITE(low, high, msrs, i);
} else {
reset_value[i] = 0;
}
}
}
static int ppro_check_ctrs(struct pt_regs * const regs,
struct op_msrs const * const msrs)
{
unsigned int low, high;
int i;
for (i = 0 ; i < num_counters; ++i) {
if (!reset_value[i])
continue;
CTR_READ(low, high, msrs, i);
if (CTR_OVERFLOWED(low)) {
oprofile_add_sample(regs, i);
wrmsrl(msrs->counters[i].addr, -reset_value[i]);
}
}
/* Only P6 based Pentium M need to re-unmask the apic vector but it
* doesn't hurt other P6 variant */
apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
/* We can't work out if we really handled an interrupt. We
* might have caught a *second* counter just after overflowing
* the interrupt for this counter then arrives
* and we don't find a counter that's overflowed, so we
* would return 0 and get dazed + confused. Instead we always
* assume we found an overflow. This sucks.
*/
return 1;
}
static void ppro_start(struct op_msrs const * const msrs)
{
unsigned int low, high;
int i;
for (i = 0; i < num_counters; ++i) {
if (reset_value[i]) {
CTRL_READ(low, high, msrs, i);
CTRL_SET_ACTIVE(low);
CTRL_WRITE(low, high, msrs, i);
}
}
}
static void ppro_stop(struct op_msrs const * const msrs)
{
unsigned int low, high;
int i;
for (i = 0; i < num_counters; ++i) {
if (!reset_value[i])
continue;
CTRL_READ(low, high, msrs, i);
CTRL_SET_INACTIVE(low);
CTRL_WRITE(low, high, msrs, i);
}
}
static void ppro_shutdown(struct op_msrs const * const msrs)
{
int i;
for (i = 0 ; i < num_counters ; ++i) {
if (CTR_IS_RESERVED(msrs, i))
release_perfctr_nmi(MSR_P6_PERFCTR0 + i);
}
for (i = 0 ; i < num_counters ; ++i) {
if (CTRL_IS_RESERVED(msrs, i))
release_evntsel_nmi(MSR_P6_EVNTSEL0 + i);
}
if (reset_value) {
kfree(reset_value);
reset_value = NULL;
}
}
struct op_x86_model_spec const op_ppro_spec = {
.num_counters = 2,
.num_controls = 2,
.fill_in_addresses = &ppro_fill_in_addresses,
.setup_ctrs = &ppro_setup_ctrs,
.check_ctrs = &ppro_check_ctrs,
.start = &ppro_start,
.stop = &ppro_stop,
.shutdown = &ppro_shutdown
};
/*
* Architectural performance monitoring.
*
* Newer Intel CPUs (Core1+) have support for architectural
* events described in CPUID 0xA. See the IA32 SDM Vol3b.18 for details.
* The advantage of this is that it can be done without knowing about
* the specific CPU.
*/
void arch_perfmon_setup_counters(void)
{
union cpuid10_eax eax;
eax.full = cpuid_eax(0xa);
/* Workaround for BIOS bugs in 6/15. Taken from perfmon2 */
if (eax.split.version_id == 0 && current_cpu_data.x86 == 6 &&
current_cpu_data.x86_model == 15) {
eax.split.version_id = 2;
eax.split.num_counters = 2;
eax.split.bit_width = 40;
}
num_counters = eax.split.num_counters;
op_arch_perfmon_spec.num_counters = num_counters;
op_arch_perfmon_spec.num_controls = num_counters;
}
struct op_x86_model_spec op_arch_perfmon_spec = {
/* num_counters/num_controls filled in at runtime */
.fill_in_addresses = &ppro_fill_in_addresses,
/* user space does the cpuid check for available events */
.setup_ctrs = &ppro_setup_ctrs,
.check_ctrs = &ppro_check_ctrs,
.start = &ppro_start,
.stop = &ppro_stop,
.shutdown = &ppro_shutdown
};