freebsd-skq/sys/dev/hwpmc/hwpmc_soft.c
Fabien Thomas f5f9340b98 Add software PMC support.
New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).

Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.

Sponsored by: NETASQ
MFC after:	1 month
2012-03-28 20:58:30 +00:00

486 lines
11 KiB
C

/*-
* Copyright (c) 2012 Fabien Thomas
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/pmc.h>
#include <sys/pmckern.h>
#include <sys/systm.h>
#include <sys/mutex.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include "hwpmc_soft.h"
/*
* Software PMC support.
*/
#define SOFT_CAPS (PMC_CAP_READ | PMC_CAP_WRITE | PMC_CAP_INTERRUPT | \
PMC_CAP_USER | PMC_CAP_SYSTEM)
struct soft_descr {
struct pmc_descr pm_descr; /* "base class" */
};
static struct soft_descr soft_pmcdesc[SOFT_NPMCS] =
{
#define SOFT_PMCDESCR(N) \
{ \
.pm_descr = \
{ \
.pd_name = #N, \
.pd_class = PMC_CLASS_SOFT, \
.pd_caps = SOFT_CAPS, \
.pd_width = 64 \
}, \
}
SOFT_PMCDESCR(SOFT0),
SOFT_PMCDESCR(SOFT1),
SOFT_PMCDESCR(SOFT2),
SOFT_PMCDESCR(SOFT3),
SOFT_PMCDESCR(SOFT4),
SOFT_PMCDESCR(SOFT5),
SOFT_PMCDESCR(SOFT6),
SOFT_PMCDESCR(SOFT7),
SOFT_PMCDESCR(SOFT8),
SOFT_PMCDESCR(SOFT9),
SOFT_PMCDESCR(SOFT10),
SOFT_PMCDESCR(SOFT11),
SOFT_PMCDESCR(SOFT12),
SOFT_PMCDESCR(SOFT13),
SOFT_PMCDESCR(SOFT14),
SOFT_PMCDESCR(SOFT15)
};
/*
* Per-CPU data structure.
*/
struct soft_cpu {
struct pmc_hw soft_hw[SOFT_NPMCS];
pmc_value_t soft_values[SOFT_NPMCS];
};
static struct soft_cpu **soft_pcpu;
static int
soft_allocate_pmc(int cpu, int ri, struct pmc *pm,
const struct pmc_op_pmcallocate *a)
{
enum pmc_event ev;
struct pmc_soft *ps;
(void) cpu;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
if (a->pm_class != PMC_CLASS_SOFT)
return (EINVAL);
if ((pm->pm_caps & SOFT_CAPS) == 0)
return (EINVAL);
if ((pm->pm_caps & ~SOFT_CAPS) != 0)
return (EPERM);
ev = pm->pm_event;
if (ev < PMC_EV_SOFT_FIRST || ev > PMC_EV_SOFT_LAST)
return (EINVAL);
/* Check if event is registered. */
ps = pmc_soft_ev_acquire(ev);
if (ps == NULL)
return (EINVAL);
pmc_soft_ev_release(ps);
return (0);
}
static int
soft_config_pmc(int cpu, int ri, struct pmc *pm)
{
struct pmc_hw *phw;
PMCDBG(MDP,CFG,1, "cpu=%d ri=%d pm=%p", cpu, ri, pm);
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
phw = &soft_pcpu[cpu]->soft_hw[ri];
KASSERT(pm == NULL || phw->phw_pmc == NULL,
("[soft,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
pm, phw->phw_pmc));
phw->phw_pmc = pm;
return (0);
}
static int
soft_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
{
int error;
size_t copied;
const struct soft_descr *pd;
struct pmc_hw *phw;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
phw = &soft_pcpu[cpu]->soft_hw[ri];
pd = &soft_pmcdesc[ri];
if ((error = copystr(pd->pm_descr.pd_name, pi->pm_name,
PMC_NAME_MAX, &copied)) != 0)
return (error);
pi->pm_class = pd->pm_descr.pd_class;
if (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) {
pi->pm_enabled = TRUE;
*ppmc = phw->phw_pmc;
} else {
pi->pm_enabled = FALSE;
*ppmc = NULL;
}
return (0);
}
static int
soft_get_config(int cpu, int ri, struct pmc **ppm)
{
(void) ri;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
*ppm = soft_pcpu[cpu]->soft_hw[ri].phw_pmc;
return (0);
}
static int
soft_pcpu_fini(struct pmc_mdep *md, int cpu)
{
int ri;
struct pmc_cpu *pc;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal cpu %d", __LINE__, cpu));
KASSERT(soft_pcpu[cpu] != NULL, ("[soft,%d] null pcpu", __LINE__));
free(soft_pcpu[cpu], M_PMC);
soft_pcpu[cpu] = NULL;
ri = md->pmd_classdep[PMC_CLASS_INDEX_SOFT].pcd_ri;
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] ri=%d", __LINE__, ri));
pc = pmc_pcpu[cpu];
pc->pc_hwpmcs[ri] = NULL;
return (0);
}
static int
soft_pcpu_init(struct pmc_mdep *md, int cpu)
{
int first_ri, n;
struct pmc_cpu *pc;
struct soft_cpu *soft_pc;
struct pmc_hw *phw;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal cpu %d", __LINE__, cpu));
KASSERT(soft_pcpu, ("[soft,%d] null pcpu", __LINE__));
KASSERT(soft_pcpu[cpu] == NULL, ("[soft,%d] non-null per-cpu",
__LINE__));
soft_pc = malloc(sizeof(struct soft_cpu), M_PMC, M_WAITOK|M_ZERO);
if (soft_pc == NULL)
return (ENOMEM);
pc = pmc_pcpu[cpu];
KASSERT(pc != NULL, ("[soft,%d] cpu %d null per-cpu", __LINE__, cpu));
soft_pcpu[cpu] = soft_pc;
phw = soft_pc->soft_hw;
first_ri = md->pmd_classdep[PMC_CLASS_INDEX_SOFT].pcd_ri;
for (n = 0; n < SOFT_NPMCS; n++, phw++) {
phw->phw_state = PMC_PHW_FLAG_IS_ENABLED |
PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(n);
phw->phw_pmc = NULL;
pc->pc_hwpmcs[n + first_ri] = phw;
}
return (0);
}
static int
soft_read_pmc(int cpu, int ri, pmc_value_t *v)
{
struct pmc *pm;
const struct pmc_hw *phw;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
phw = &soft_pcpu[cpu]->soft_hw[ri];
pm = phw->phw_pmc;
KASSERT(pm != NULL,
("[soft,%d] no owner for PHW [cpu%d,pmc%d]", __LINE__, cpu, ri));
PMCDBG(MDP,REA,1,"soft-read id=%d", ri);
*v = soft_pcpu[cpu]->soft_values[ri];
return (0);
}
static int
soft_write_pmc(int cpu, int ri, pmc_value_t v)
{
struct pmc *pm;
const struct soft_descr *pd;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal cpu value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
pm = soft_pcpu[cpu]->soft_hw[ri].phw_pmc;
pd = &soft_pmcdesc[ri];
KASSERT(pm,
("[soft,%d] cpu %d ri %d pmc not configured", __LINE__, cpu, ri));
PMCDBG(MDP,WRI,1, "soft-write cpu=%d ri=%d v=%jx", cpu, ri, v);
soft_pcpu[cpu]->soft_values[ri] = v;
return (0);
}
static int
soft_release_pmc(int cpu, int ri, struct pmc *pmc)
{
struct pmc_hw *phw;
(void) pmc;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
phw = &soft_pcpu[cpu]->soft_hw[ri];
KASSERT(phw->phw_pmc == NULL,
("[soft,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
/*
* Nothing to do.
*/
return (0);
}
static int
soft_start_pmc(int cpu, int ri)
{
struct pmc *pm;
struct soft_cpu *pc;
struct pmc_soft *ps;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
pc = soft_pcpu[cpu];
pm = pc->soft_hw[ri].phw_pmc;
KASSERT(pm,
("[soft,%d] cpu %d ri %d pmc not configured", __LINE__, cpu, ri));
ps = pmc_soft_ev_acquire(pm->pm_event);
if (ps == NULL)
return (EINVAL);
atomic_add_int(&ps->ps_running, 1);
pmc_soft_ev_release(ps);
return (0);
}
static int
soft_stop_pmc(int cpu, int ri)
{
struct pmc *pm;
struct soft_cpu *pc;
struct pmc_soft *ps;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[soft,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < SOFT_NPMCS,
("[soft,%d] illegal row-index %d", __LINE__, ri));
pc = soft_pcpu[cpu];
pm = pc->soft_hw[ri].phw_pmc;
KASSERT(pm,
("[soft,%d] cpu %d ri %d pmc not configured", __LINE__, cpu, ri));
ps = pmc_soft_ev_acquire(pm->pm_event);
/* event unregistered ? */
if (ps != NULL) {
atomic_subtract_int(&ps->ps_running, 1);
pmc_soft_ev_release(ps);
}
return (0);
}
int
pmc_soft_intr(struct pmckern_soft *ks)
{
struct pmc *pm;
struct soft_cpu *pc;
int ri, processed, error, user_mode;
KASSERT(ks->pm_cpu >= 0 && ks->pm_cpu < pmc_cpu_max(),
("[soft,%d] CPU %d out of range", __LINE__, ks->pm_cpu));
processed = 0;
pc = soft_pcpu[ks->pm_cpu];
for (ri = 0; ri < SOFT_NPMCS; ri++) {
pm = pc->soft_hw[ri].phw_pmc;
if (pm == NULL ||
pm->pm_state != PMC_STATE_RUNNING ||
pm->pm_event != ks->pm_ev) {
continue;
}
processed = 1;
pc->soft_values[ri]++;
if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
user_mode = TRAPF_USERMODE(ks->pm_tf);
error = pmc_process_interrupt(ks->pm_cpu, PMC_SR, pm,
ks->pm_tf, user_mode);
if (error) {
soft_stop_pmc(ks->pm_cpu, ri);
continue;
}
if (user_mode) {
/* If in user mode setup AST to process
* callchain out of interrupt context.
*/
curthread->td_flags |= TDF_ASTPENDING;
}
}
}
atomic_add_int(processed ? &pmc_stats.pm_intr_processed :
&pmc_stats.pm_intr_ignored, 1);
return (processed);
}
void
pmc_soft_initialize(struct pmc_mdep *md)
{
struct pmc_classdep *pcd;
/* Add SOFT PMCs. */
soft_pcpu = malloc(sizeof(struct soft_cpu *) * pmc_cpu_max(), M_PMC,
M_ZERO|M_WAITOK);
pcd = &md->pmd_classdep[PMC_CLASS_INDEX_SOFT];
pcd->pcd_caps = SOFT_CAPS;
pcd->pcd_class = PMC_CLASS_SOFT;
pcd->pcd_num = SOFT_NPMCS;
pcd->pcd_ri = md->pmd_npmc;
pcd->pcd_width = 64;
pcd->pcd_allocate_pmc = soft_allocate_pmc;
pcd->pcd_config_pmc = soft_config_pmc;
pcd->pcd_describe = soft_describe;
pcd->pcd_get_config = soft_get_config;
pcd->pcd_get_msr = NULL;
pcd->pcd_pcpu_init = soft_pcpu_init;
pcd->pcd_pcpu_fini = soft_pcpu_fini;
pcd->pcd_read_pmc = soft_read_pmc;
pcd->pcd_write_pmc = soft_write_pmc;
pcd->pcd_release_pmc = soft_release_pmc;
pcd->pcd_start_pmc = soft_start_pmc;
pcd->pcd_stop_pmc = soft_stop_pmc;
md->pmd_npmc += SOFT_NPMCS;
}
void
pmc_soft_finalize(struct pmc_mdep *md)
{
#ifdef INVARIANTS
int i, ncpus;
ncpus = pmc_cpu_max();
for (i = 0; i < ncpus; i++)
KASSERT(soft_pcpu[i] == NULL, ("[soft,%d] non-null pcpu cpu %d",
__LINE__, i));
KASSERT(md->pmd_classdep[PMC_CLASS_INDEX_SOFT].pcd_class ==
PMC_CLASS_SOFT, ("[soft,%d] class mismatch", __LINE__));
#endif
free(soft_pcpu, M_PMC);
soft_pcpu = NULL;
}