freebsd-skq/sys/dev/hwpmc/hwpmc_tsc.c
fabient 5edfb77dd3 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

386 lines
8.8 KiB
C

/*-
* Copyright (c) 2008 Joseph Koshy
* 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 <machine/specialreg.h>
/*
* TSC support.
*/
#define TSC_CAPS PMC_CAP_READ
struct tsc_descr {
struct pmc_descr pm_descr; /* "base class" */
};
static struct tsc_descr tsc_pmcdesc[TSC_NPMCS] =
{
{
.pm_descr =
{
.pd_name = "TSC",
.pd_class = PMC_CLASS_TSC,
.pd_caps = TSC_CAPS,
.pd_width = 64
}
}
};
/*
* Per-CPU data structure for TSCs.
*/
struct tsc_cpu {
struct pmc_hw tc_hw;
};
static struct tsc_cpu **tsc_pcpu;
static int
tsc_allocate_pmc(int cpu, int ri, struct pmc *pm,
const struct pmc_op_pmcallocate *a)
{
(void) cpu;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri >= 0 && ri < TSC_NPMCS,
("[tsc,%d] illegal row index %d", __LINE__, ri));
if (a->pm_class != PMC_CLASS_TSC)
return (EINVAL);
if ((pm->pm_caps & TSC_CAPS) == 0)
return (EINVAL);
if ((pm->pm_caps & ~TSC_CAPS) != 0)
return (EPERM);
if (a->pm_ev != PMC_EV_TSC_TSC ||
a->pm_mode != PMC_MODE_SC)
return (EINVAL);
return (0);
}
static int
tsc_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(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
phw = &tsc_pcpu[cpu]->tc_hw;
KASSERT(pm == NULL || phw->phw_pmc == NULL,
("[tsc,%d] pm=%p phw->pm=%p hwpmc not unconfigured", __LINE__,
pm, phw->phw_pmc));
phw->phw_pmc = pm;
return (0);
}
static int
tsc_describe(int cpu, int ri, struct pmc_info *pi, struct pmc **ppmc)
{
int error;
size_t copied;
const struct tsc_descr *pd;
struct pmc_hw *phw;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
phw = &tsc_pcpu[cpu]->tc_hw;
pd = &tsc_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
tsc_get_config(int cpu, int ri, struct pmc **ppm)
{
(void) ri;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
*ppm = tsc_pcpu[cpu]->tc_hw.phw_pmc;
return (0);
}
static int
tsc_get_msr(int ri, uint32_t *msr)
{
(void) ri;
KASSERT(ri >= 0 && ri < TSC_NPMCS,
("[tsc,%d] ri %d out of range", __LINE__, ri));
*msr = MSR_TSC;
return (0);
}
static int
tsc_pcpu_fini(struct pmc_mdep *md, int cpu)
{
int ri;
struct pmc_cpu *pc;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal cpu %d", __LINE__, cpu));
KASSERT(tsc_pcpu[cpu] != NULL, ("[tsc,%d] null pcpu", __LINE__));
free(tsc_pcpu[cpu], M_PMC);
tsc_pcpu[cpu] = NULL;
ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
pc = pmc_pcpu[cpu];
pc->pc_hwpmcs[ri] = NULL;
return (0);
}
static int
tsc_pcpu_init(struct pmc_mdep *md, int cpu)
{
int ri;
struct pmc_cpu *pc;
struct tsc_cpu *tsc_pc;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal cpu %d", __LINE__, cpu));
KASSERT(tsc_pcpu, ("[tsc,%d] null pcpu", __LINE__));
KASSERT(tsc_pcpu[cpu] == NULL, ("[tsc,%d] non-null per-cpu",
__LINE__));
tsc_pc = malloc(sizeof(struct tsc_cpu), M_PMC, M_WAITOK|M_ZERO);
tsc_pc->tc_hw.phw_state = PMC_PHW_FLAG_IS_ENABLED |
PMC_PHW_CPU_TO_STATE(cpu) | PMC_PHW_INDEX_TO_STATE(0) |
PMC_PHW_FLAG_IS_SHAREABLE;
tsc_pcpu[cpu] = tsc_pc;
ri = md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_ri;
KASSERT(pmc_pcpu, ("[tsc,%d] null generic pcpu", __LINE__));
pc = pmc_pcpu[cpu];
KASSERT(pc, ("[tsc,%d] null generic per-cpu", __LINE__));
pc->pc_hwpmcs[ri] = &tsc_pc->tc_hw;
return (0);
}
static int
tsc_read_pmc(int cpu, int ri, pmc_value_t *v)
{
struct pmc *pm;
enum pmc_mode mode;
const struct pmc_hw *phw;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal ri %d", __LINE__, ri));
phw = &tsc_pcpu[cpu]->tc_hw;
pm = phw->phw_pmc;
KASSERT(pm != NULL,
("[tsc,%d] no owner for PHW [cpu%d,pmc%d]", __LINE__, cpu, ri));
mode = PMC_TO_MODE(pm);
KASSERT(mode == PMC_MODE_SC,
("[tsc,%d] illegal pmc mode %d", __LINE__, mode));
PMCDBG(MDP,REA,1,"tsc-read id=%d", ri);
*v = rdtsc();
return (0);
}
static int
tsc_release_pmc(int cpu, int ri, struct pmc *pmc)
{
struct pmc_hw *phw;
(void) pmc;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0,
("[tsc,%d] illegal row-index %d", __LINE__, ri));
phw = &tsc_pcpu[cpu]->tc_hw;
KASSERT(phw->phw_pmc == NULL,
("[tsc,%d] PHW pmc %p non-NULL", __LINE__, phw->phw_pmc));
/*
* Nothing to do.
*/
return (0);
}
static int
tsc_start_pmc(int cpu, int ri)
{
(void) cpu;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
return (0); /* TSCs are always running. */
}
static int
tsc_stop_pmc(int cpu, int ri)
{
(void) cpu; (void) ri;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
return (0); /* Cannot actually stop a TSC. */
}
static int
tsc_write_pmc(int cpu, int ri, pmc_value_t v)
{
(void) cpu; (void) ri; (void) v;
KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
("[tsc,%d] illegal CPU value %d", __LINE__, cpu));
KASSERT(ri == 0, ("[tsc,%d] illegal row-index %d", __LINE__, ri));
/*
* The TSCs are used as timecounters by the kernel, so even
* though some i386 CPUs support writeable TSCs, we don't
* support writing changing TSC values through the HWPMC API.
*/
return (0);
}
int
pmc_tsc_initialize(struct pmc_mdep *md, int maxcpu)
{
struct pmc_classdep *pcd;
KASSERT(md != NULL, ("[tsc,%d] md is NULL", __LINE__));
KASSERT(md->pmd_nclass >= 1, ("[tsc,%d] dubious md->nclass %d",
__LINE__, md->pmd_nclass));
tsc_pcpu = malloc(sizeof(struct tsc_cpu *) * maxcpu, M_PMC,
M_ZERO|M_WAITOK);
pcd = &md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC];
pcd->pcd_caps = PMC_CAP_READ;
pcd->pcd_class = PMC_CLASS_TSC;
pcd->pcd_num = TSC_NPMCS;
pcd->pcd_ri = md->pmd_npmc;
pcd->pcd_width = 64;
pcd->pcd_allocate_pmc = tsc_allocate_pmc;
pcd->pcd_config_pmc = tsc_config_pmc;
pcd->pcd_describe = tsc_describe;
pcd->pcd_get_config = tsc_get_config;
pcd->pcd_get_msr = tsc_get_msr;
pcd->pcd_pcpu_init = tsc_pcpu_init;
pcd->pcd_pcpu_fini = tsc_pcpu_fini;
pcd->pcd_read_pmc = tsc_read_pmc;
pcd->pcd_release_pmc = tsc_release_pmc;
pcd->pcd_start_pmc = tsc_start_pmc;
pcd->pcd_stop_pmc = tsc_stop_pmc;
pcd->pcd_write_pmc = tsc_write_pmc;
md->pmd_npmc += TSC_NPMCS;
return (0);
}
void
pmc_tsc_finalize(struct pmc_mdep *md)
{
#ifdef INVARIANTS
int i, ncpus;
ncpus = pmc_cpu_max();
for (i = 0; i < ncpus; i++)
KASSERT(tsc_pcpu[i] == NULL, ("[tsc,%d] non-null pcpu cpu %d",
__LINE__, i));
KASSERT(md->pmd_classdep[PMC_MDEP_CLASS_INDEX_TSC].pcd_class ==
PMC_CLASS_TSC, ("[tsc,%d] class mismatch", __LINE__));
#else
(void) md;
#endif
free(tsc_pcpu, M_PMC);
tsc_pcpu = NULL;
}