diff --git a/sys/dev/hwpmc/hwpmc_tsc.c b/sys/dev/hwpmc/hwpmc_tsc.c
index 25b2e9f8fd57..3c95ceb080a5 100644
--- a/sys/dev/hwpmc/hwpmc_tsc.c
+++ b/sys/dev/hwpmc/hwpmc_tsc.c
@@ -1,376 +1,365 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * 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,
+tsc_allocate_pmc(int cpu __diagused, int ri __diagused, struct pmc *pm __unused,
     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 (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;
 
 	PMCDBG3(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)
 {
 	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];
 
 	strlcpy(pi->pm_name, pd->pm_descr.pd_name, sizeof(pi->pm_name));
 	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)
+tsc_get_config(int cpu, int ri __diagused, 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)
+tsc_get_msr(int ri __diagused, 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 __diagused;
 	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));
 
 	PMCDBG1(MDP,REA,1,"tsc-read id=%d", ri);
 
 	*v = rdtsc();
 
 	return (0);
 }
 
 static int
-tsc_release_pmc(int cpu, int ri, struct pmc *pmc)
+tsc_release_pmc(int cpu, int ri __diagused, struct pmc *pmc __unused)
 {
 	struct pmc_hw *phw __diagused;
 
-	(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)
+tsc_start_pmc(int cpu __diagused, int ri __diagused)
 {
-	(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)
+tsc_stop_pmc(int cpu __diagused, int ri __diagused)
 {
-	(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)
+tsc_write_pmc(int cpu __diagused, int ri __diagused, pmc_value_t v __unused)
 {
-	(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)
+pmc_tsc_finalize(struct pmc_mdep *md __diagused)
 {
 #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;
 }