FreeBSD/Linux Kernel Cross Reference
sys/dev/hwpmc/hwpmc_tsc.c

     /*-
      * 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,
        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)
   {
           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 __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)
   {
           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)
   {
           (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;
   }

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