FreeBSD/Linux Kernel Cross Reference
sys/sys/pmc.h

     /*-
      * Copyright (c) 2003-2008, Joseph Koshy
      * Copyright (c) 2007 The FreeBSD Foundation
      * All rights reserved.
      *
      * Portions of this software were developed by A. Joseph Koshy under
      * sponsorship from the FreeBSD Foundation and Google, Inc.
      *
      * 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.
     *
     * $FreeBSD: releng/10.2/sys/sys/pmc.h 283884 2015-06-01 17:57:05Z jhb $
     */
    
    #ifndef _SYS_PMC_H_
    #define _SYS_PMC_H_
    
    #include <dev/hwpmc/pmc_events.h>
    
    #include <machine/pmc_mdep.h>
    #include <machine/profile.h>
    
    #define PMC_MODULE_NAME         "hwpmc"
    #define PMC_NAME_MAX            64 /* HW counter name size */
    #define PMC_CLASS_MAX           8  /* max #classes of PMCs per-system */
    
    /*
     * Kernel<->userland API version number [MMmmpppp]
     *
     * Major numbers are to be incremented when an incompatible change to
     * the ABI occurs that older clients will not be able to handle.
     *
     * Minor numbers are incremented when a backwards compatible change
     * occurs that allows older correct programs to run unchanged.  For
     * example, when support for a new PMC type is added.
     *
     * The patch version is incremented for every bug fix.
     */
    #define PMC_VERSION_MAJOR       0x03
    #define PMC_VERSION_MINOR       0x01
    #define PMC_VERSION_PATCH       0x0000
    
    #define PMC_VERSION             (PMC_VERSION_MAJOR << 24 |              \
            PMC_VERSION_MINOR << 16 | PMC_VERSION_PATCH)
    
    /*
     * Kinds of CPUs known.
     *
     * We keep track of CPU variants that need to be distinguished in
     * some way for PMC operations.  CPU names are grouped by manufacturer
     * and numbered sparsely in order to minimize changes to the ABI involved
     * when new CPUs are added.
     */
    
    #define __PMC_CPUS()                                            \
            __PMC_CPU(AMD_K7,       0x00,   "AMD K7")               \
            __PMC_CPU(AMD_K8,       0x01,   "AMD K8")               \
            __PMC_CPU(INTEL_P5,     0x80,   "Intel Pentium")        \
            __PMC_CPU(INTEL_P6,     0x81,   "Intel Pentium Pro")    \
            __PMC_CPU(INTEL_CL,     0x82,   "Intel Celeron")        \
            __PMC_CPU(INTEL_PII,    0x83,   "Intel Pentium II")     \
            __PMC_CPU(INTEL_PIII,   0x84,   "Intel Pentium III")    \
            __PMC_CPU(INTEL_PM,     0x85,   "Intel Pentium M")      \
            __PMC_CPU(INTEL_PIV,    0x86,   "Intel Pentium IV")     \
            __PMC_CPU(INTEL_CORE,   0x87,   "Intel Core Solo/Duo")  \
            __PMC_CPU(INTEL_CORE2,  0x88,   "Intel Core2")          \
            __PMC_CPU(INTEL_CORE2EXTREME,   0x89,   "Intel Core2 Extreme")  \
            __PMC_CPU(INTEL_ATOM,   0x8A,   "Intel Atom")           \
            __PMC_CPU(INTEL_COREI7, 0x8B,   "Intel Core i7")        \
            __PMC_CPU(INTEL_WESTMERE, 0x8C,   "Intel Westmere")     \
            __PMC_CPU(INTEL_SANDYBRIDGE, 0x8D,   "Intel Sandy Bridge")      \
            __PMC_CPU(INTEL_IVYBRIDGE, 0x8E,   "Intel Ivy Bridge")  \
            __PMC_CPU(INTEL_SANDYBRIDGE_XEON, 0x8F,   "Intel Sandy Bridge Xeon")    \
            __PMC_CPU(INTEL_IVYBRIDGE_XEON, 0x90,   "Intel Ivy Bridge Xeon")        \
            __PMC_CPU(INTEL_HASWELL, 0x91,   "Intel Haswell")       \
            __PMC_CPU(INTEL_ATOM_SILVERMONT, 0x92,  "Intel Atom Silvermont")    \
            __PMC_CPU(INTEL_NEHALEM_EX, 0x93,   "Intel Nehalem Xeon 7500")  \
            __PMC_CPU(INTEL_WESTMERE_EX, 0x94,   "Intel Westmere Xeon E7")  \
            __PMC_CPU(INTEL_HASWELL_XEON, 0x95,   "Intel Haswell Xeon E5 v3") \
            __PMC_CPU(INTEL_XSCALE, 0x100,  "Intel XScale")         \
            __PMC_CPU(MIPS_24K,     0x200,  "MIPS 24K")             \
           __PMC_CPU(MIPS_OCTEON,  0x201,  "Cavium Octeon")        \
           __PMC_CPU(PPC_7450,     0x300,  "PowerPC MPC7450")      \
           __PMC_CPU(PPC_970,      0x380,  "IBM PowerPC 970")      \
           __PMC_CPU(GENERIC,      0x400,  "Generic")
   
   enum pmc_cputype {
   #undef  __PMC_CPU
   #define __PMC_CPU(S,V,D)        PMC_CPU_##S = V,
           __PMC_CPUS()
   };
   
   #define PMC_CPU_FIRST   PMC_CPU_AMD_K7
   #define PMC_CPU_LAST    PMC_CPU_GENERIC
   
   /*
    * Classes of PMCs
    */
   
   #define __PMC_CLASSES()                                                 \
           __PMC_CLASS(TSC)        /* CPU Timestamp counter */             \
           __PMC_CLASS(K7)         /* AMD K7 performance counters */       \
           __PMC_CLASS(K8)         /* AMD K8 performance counters */       \
           __PMC_CLASS(P5)         /* Intel Pentium counters */            \
           __PMC_CLASS(P6)         /* Intel Pentium Pro counters */        \
           __PMC_CLASS(P4)         /* Intel Pentium-IV counters */         \
           __PMC_CLASS(IAF)        /* Intel Core2/Atom, fixed function */  \
           __PMC_CLASS(IAP)        /* Intel Core...Atom, programmable */   \
           __PMC_CLASS(UCF)        /* Intel Uncore fixed function */       \
           __PMC_CLASS(UCP)        /* Intel Uncore programmable */         \
           __PMC_CLASS(XSCALE)     /* Intel XScale counters */             \
           __PMC_CLASS(MIPS24K)    /* MIPS 24K */                          \
           __PMC_CLASS(OCTEON)     /* Cavium Octeon */                     \
           __PMC_CLASS(PPC7450)    /* Motorola MPC7450 class */            \
           __PMC_CLASS(PPC970)     /* IBM PowerPC 970 class */             \
           __PMC_CLASS(SOFT)       /* Software events */
   
   enum pmc_class {
   #undef  __PMC_CLASS
   #define __PMC_CLASS(N)  PMC_CLASS_##N ,
           __PMC_CLASSES()
   };
   
   #define PMC_CLASS_FIRST PMC_CLASS_TSC
   #define PMC_CLASS_LAST  PMC_CLASS_SOFT
   
   /*
    * A PMC can be in the following states:
    *
    * Hardware states:
    *   DISABLED   -- administratively prohibited from being used.
    *   FREE       -- HW available for use
    * Software states:
    *   ALLOCATED  -- allocated
    *   STOPPED    -- allocated, but not counting events
    *   RUNNING    -- allocated, and in operation; 'pm_runcount'
    *                 holds the number of CPUs using this PMC at
    *                 a given instant
    *   DELETED    -- being destroyed
    */
   
   #define __PMC_HWSTATES()                        \
           __PMC_STATE(DISABLED)                   \
           __PMC_STATE(FREE)
   
   #define __PMC_SWSTATES()                        \
           __PMC_STATE(ALLOCATED)                  \
           __PMC_STATE(STOPPED)                    \
           __PMC_STATE(RUNNING)                    \
           __PMC_STATE(DELETED)
   
   #define __PMC_STATES()                          \
           __PMC_HWSTATES()                        \
           __PMC_SWSTATES()
   
   enum pmc_state {
   #undef  __PMC_STATE
   #define __PMC_STATE(S)  PMC_STATE_##S,
           __PMC_STATES()
           __PMC_STATE(MAX)
   };
   
   #define PMC_STATE_FIRST PMC_STATE_DISABLED
   #define PMC_STATE_LAST  PMC_STATE_DELETED
   
   /*
    * An allocated PMC may used as a 'global' counter or as a
    * 'thread-private' one.  Each such mode of use can be in either
    * statistical sampling mode or in counting mode.  Thus a PMC in use
    *
    * SS i.e., SYSTEM STATISTICAL  -- system-wide statistical profiling
    * SC i.e., SYSTEM COUNTER      -- system-wide counting mode
    * TS i.e., THREAD STATISTICAL  -- thread virtual, statistical profiling
    * TC i.e., THREAD COUNTER      -- thread virtual, counting mode
    *
    * Statistical profiling modes rely on the PMC periodically delivering
    * a interrupt to the CPU (when the configured number of events have
    * been measured), so the PMC must have the ability to generate
    * interrupts.
    *
    * In counting modes, the PMC counts its configured events, with the
    * value of the PMC being read whenever needed by its owner process.
    *
    * The thread specific modes "virtualize" the PMCs -- the PMCs appear
    * to be thread private and count events only when the profiled thread
    * actually executes on the CPU.
    *
    * The system-wide "global" modes keep the PMCs running all the time
    * and are used to measure the behaviour of the whole system.
    */
   
   #define __PMC_MODES()                           \
           __PMC_MODE(SS,  0)                      \
           __PMC_MODE(SC,  1)                      \
           __PMC_MODE(TS,  2)                      \
           __PMC_MODE(TC,  3)
   
   enum pmc_mode {
   #undef  __PMC_MODE
   #define __PMC_MODE(M,N) PMC_MODE_##M = N,
           __PMC_MODES()
   };
   
   #define PMC_MODE_FIRST  PMC_MODE_SS
   #define PMC_MODE_LAST   PMC_MODE_TC
   
   #define PMC_IS_COUNTING_MODE(mode)                              \
           ((mode) == PMC_MODE_SC || (mode) == PMC_MODE_TC)
   #define PMC_IS_SYSTEM_MODE(mode)                                \
           ((mode) == PMC_MODE_SS || (mode) == PMC_MODE_SC)
   #define PMC_IS_SAMPLING_MODE(mode)                              \
           ((mode) == PMC_MODE_SS || (mode) == PMC_MODE_TS)
   #define PMC_IS_VIRTUAL_MODE(mode)                               \
           ((mode) == PMC_MODE_TS || (mode) == PMC_MODE_TC)
   
   /*
    * PMC row disposition
    */
   
   #define __PMC_DISPOSITIONS(N)                                   \
           __PMC_DISP(STANDALONE)  /* global/disabled counters */  \
           __PMC_DISP(FREE)        /* free/available */            \
           __PMC_DISP(THREAD)      /* thread-virtual PMCs */       \
           __PMC_DISP(UNKNOWN)     /* sentinel */
   
   enum pmc_disp {
   #undef  __PMC_DISP
   #define __PMC_DISP(D)   PMC_DISP_##D ,
           __PMC_DISPOSITIONS()
   };
   
   #define PMC_DISP_FIRST  PMC_DISP_STANDALONE
   #define PMC_DISP_LAST   PMC_DISP_THREAD
   
   /*
    * Counter capabilities
    *
    * __PMC_CAPS(NAME, VALUE, DESCRIPTION)
    */
   
   #define __PMC_CAPS()                                                    \
           __PMC_CAP(INTERRUPT,    0, "generate interrupts")               \
           __PMC_CAP(USER,         1, "count user-mode events")            \
           __PMC_CAP(SYSTEM,       2, "count system-mode events")          \
           __PMC_CAP(EDGE,         3, "do edge detection of events")       \
           __PMC_CAP(THRESHOLD,    4, "ignore events below a threshold")   \
           __PMC_CAP(READ,         5, "read PMC counter")                  \
           __PMC_CAP(WRITE,        6, "reprogram PMC counter")             \
           __PMC_CAP(INVERT,       7, "invert comparision sense")          \
           __PMC_CAP(QUALIFIER,    8, "further qualify monitored events")  \
           __PMC_CAP(PRECISE,      9, "perform precise sampling")          \
           __PMC_CAP(TAGGING,      10, "tag upstream events")              \
           __PMC_CAP(CASCADE,      11, "cascade counters")
   
   enum pmc_caps
   {
   #undef  __PMC_CAP
   #define __PMC_CAP(NAME, VALUE, DESCR)   PMC_CAP_##NAME = (1 << VALUE) ,
           __PMC_CAPS()
   };
   
   #define PMC_CAP_FIRST           PMC_CAP_INTERRUPT
   #define PMC_CAP_LAST            PMC_CAP_CASCADE
   
   /*
    * PMC Event Numbers
    *
    * These are generated from the definitions in "dev/hwpmc/pmc_events.h".
    */
   
   enum pmc_event {
   #undef  __PMC_EV
   #undef  __PMC_EV_BLOCK
   #define __PMC_EV_BLOCK(C,V)     PMC_EV_ ## C ## __BLOCK_START = (V) - 1 ,
   #define __PMC_EV(C,N)           PMC_EV_ ## C ## _ ## N ,
           __PMC_EVENTS()
   };
   
   /*
    * PMC SYSCALL INTERFACE
    */
   
   /*
    * "PMC_OPS" -- these are the commands recognized by the kernel
    * module, and are used when performing a system call from userland.
    */
   #define __PMC_OPS()                                                     \
           __PMC_OP(CONFIGURELOG, "Set log file")                          \
           __PMC_OP(FLUSHLOG, "Flush log file")                            \
           __PMC_OP(GETCPUINFO, "Get system CPU information")              \
           __PMC_OP(GETDRIVERSTATS, "Get driver statistics")               \
           __PMC_OP(GETMODULEVERSION, "Get module version")                \
           __PMC_OP(GETPMCINFO, "Get per-cpu PMC information")             \
           __PMC_OP(PMCADMIN, "Set PMC state")                             \
           __PMC_OP(PMCALLOCATE, "Allocate and configure a PMC")           \
           __PMC_OP(PMCATTACH, "Attach a PMC to a process")                \
           __PMC_OP(PMCDETACH, "Detach a PMC from a process")              \
           __PMC_OP(PMCGETMSR, "Get a PMC's hardware address")             \
           __PMC_OP(PMCRELEASE, "Release a PMC")                           \
           __PMC_OP(PMCRW, "Read/Set a PMC")                               \
           __PMC_OP(PMCSETCOUNT, "Set initial count/sampling rate")        \
           __PMC_OP(PMCSTART, "Start a PMC")                               \
           __PMC_OP(PMCSTOP, "Stop a PMC")                                 \
           __PMC_OP(WRITELOG, "Write a cookie to the log file")            \
           __PMC_OP(CLOSELOG, "Close log file")                            \
           __PMC_OP(GETDYNEVENTINFO, "Get dynamic events list")
   
   
   enum pmc_ops {
   #undef  __PMC_OP
   #define __PMC_OP(N, D)  PMC_OP_##N,
           __PMC_OPS()
   };
   
   
   /*
    * Flags used in operations on PMCs.
    */
   
   #define PMC_F_FORCE             0x00000001 /*OP ADMIN force operation */
   #define PMC_F_DESCENDANTS       0x00000002 /*OP ALLOCATE track descendants */
   #define PMC_F_LOG_PROCCSW       0x00000004 /*OP ALLOCATE track ctx switches */
   #define PMC_F_LOG_PROCEXIT      0x00000008 /*OP ALLOCATE log proc exits */
   #define PMC_F_NEWVALUE          0x00000010 /*OP RW write new value */
   #define PMC_F_OLDVALUE          0x00000020 /*OP RW get old value */
   #define PMC_F_KGMON             0x00000040 /*OP ALLOCATE kgmon(8) profiling */
   /* V2 API */
   #define PMC_F_CALLCHAIN         0x00000080 /*OP ALLOCATE capture callchains */
   
   /* internal flags */
   #define PMC_F_ATTACHED_TO_OWNER 0x00010000 /*attached to owner*/
   #define PMC_F_NEEDS_LOGFILE     0x00020000 /*needs log file */
   #define PMC_F_ATTACH_DONE       0x00040000 /*attached at least once */
   
   #define PMC_CALLCHAIN_DEPTH_MAX 128
   
   #define PMC_CC_F_USERSPACE      0x01       /*userspace callchain*/
   
   /*
    * Cookies used to denote allocated PMCs, and the values of PMCs.
    */
   
   typedef uint32_t        pmc_id_t;
   typedef uint64_t        pmc_value_t;
   
   #define PMC_ID_INVALID          (~ (pmc_id_t) 0)
   
   /*
    * PMC IDs have the following format:
    *
    * +--------+----------+-----------+-----------+
    * |   CPU  | PMC MODE | PMC CLASS | ROW INDEX |
    * +--------+----------+-----------+-----------+
    *
    * where each field is 8 bits wide.  Field 'CPU' is set to the
    * requested CPU for system-wide PMCs or PMC_CPU_ANY for process-mode
    * PMCs.  Field 'PMC MODE' is the allocated PMC mode.  Field 'PMC
    * CLASS' is the class of the PMC.  Field 'ROW INDEX' is the row index
    * for the PMC.
    *
    * The 'ROW INDEX' ranges over 0..NWPMCS where NHWPMCS is the total
    * number of hardware PMCs on this cpu.
    */
   
   
   #define PMC_ID_TO_ROWINDEX(ID)  ((ID) & 0xFF)
   #define PMC_ID_TO_CLASS(ID)     (((ID) & 0xFF00) >> 8)
   #define PMC_ID_TO_MODE(ID)      (((ID) & 0xFF0000) >> 16)
   #define PMC_ID_TO_CPU(ID)       (((ID) & 0xFF000000) >> 24)
   #define PMC_ID_MAKE_ID(CPU,MODE,CLASS,ROWINDEX)                 \
           ((((CPU) & 0xFF) << 24) | (((MODE) & 0xFF) << 16) |     \
           (((CLASS) & 0xFF) << 8) | ((ROWINDEX) & 0xFF))
   
   /*
    * Data structures for system calls supported by the pmc driver.
    */
   
   /*
    * OP PMCALLOCATE
    *
    * Allocate a PMC on the named CPU.
    */
   
   #define PMC_CPU_ANY     ~0
   
   struct pmc_op_pmcallocate {
           uint32_t        pm_caps;        /* PMC_CAP_* */
           uint32_t        pm_cpu;         /* CPU number or PMC_CPU_ANY */
           enum pmc_class  pm_class;       /* class of PMC desired */
           enum pmc_event  pm_ev;          /* [enum pmc_event] desired */
           uint32_t        pm_flags;       /* additional modifiers PMC_F_* */
           enum pmc_mode   pm_mode;        /* desired mode */
           pmc_id_t        pm_pmcid;       /* [return] process pmc id */
   
           union pmc_md_op_pmcallocate pm_md; /* MD layer extensions */
   };
   
   /*
    * OP PMCADMIN
    *
    * Set the administrative state (i.e., whether enabled or disabled) of
    * a PMC 'pm_pmc' on CPU 'pm_cpu'.  Note that 'pm_pmc' specifies an
    * absolute PMC number and need not have been first allocated by the
    * calling process.
    */
   
   struct pmc_op_pmcadmin {
           int             pm_cpu;         /* CPU# */
           uint32_t        pm_flags;       /* flags */
           int             pm_pmc;         /* PMC# */
           enum pmc_state  pm_state;       /* desired state */
   };
   
   /*
    * OP PMCATTACH / OP PMCDETACH
    *
    * Attach/detach a PMC and a process.
    */
   
   struct pmc_op_pmcattach {
           pmc_id_t        pm_pmc;         /* PMC to attach to */
           pid_t           pm_pid;         /* target process */
   };
   
   /*
    * OP PMCSETCOUNT
    *
    * Set the sampling rate (i.e., the reload count) for statistical counters.
    * 'pm_pmcid' need to have been previously allocated using PMCALLOCATE.
    */
   
   struct pmc_op_pmcsetcount {
           pmc_value_t     pm_count;       /* initial/sample count */
           pmc_id_t        pm_pmcid;       /* PMC id to set */
   };
   
   
   /*
    * OP PMCRW
    *
    * Read the value of a PMC named by 'pm_pmcid'.  'pm_pmcid' needs
    * to have been previously allocated using PMCALLOCATE.
    */
   
   
   struct pmc_op_pmcrw {
           uint32_t        pm_flags;       /* PMC_F_{OLD,NEW}VALUE*/
           pmc_id_t        pm_pmcid;       /* pmc id */
           pmc_value_t     pm_value;       /* new&returned value */
   };
   
   
   /*
    * OP GETPMCINFO
    *
    * retrieve PMC state for a named CPU.  The caller is expected to
    * allocate 'npmc' * 'struct pmc_info' bytes of space for the return
    * values.
    */
   
   struct pmc_info {
           char            pm_name[PMC_NAME_MAX]; /* pmc name */
           enum pmc_class  pm_class;       /* enum pmc_class */
           int             pm_enabled;     /* whether enabled */
           enum pmc_disp   pm_rowdisp;     /* FREE, THREAD or STANDLONE */
           pid_t           pm_ownerpid;    /* owner, or -1 */
           enum pmc_mode   pm_mode;        /* current mode [enum pmc_mode] */
           enum pmc_event  pm_event;       /* current event */
           uint32_t        pm_flags;       /* current flags */
           pmc_value_t     pm_reloadcount; /* sampling counters only */
   };
   
   struct pmc_op_getpmcinfo {
           int32_t         pm_cpu;         /* 0 <= cpu < mp_maxid */
           struct pmc_info pm_pmcs[];      /* space for 'npmc' structures */
   };
   
   
   /*
    * OP GETCPUINFO
    *
    * Retrieve system CPU information.
    */
   
   
   struct pmc_classinfo {
           enum pmc_class  pm_class;       /* class id */
           uint32_t        pm_caps;        /* counter capabilities */
           uint32_t        pm_width;       /* width of the PMC */
           uint32_t        pm_num;         /* number of PMCs in class */
   };
   
   struct pmc_op_getcpuinfo {
           enum pmc_cputype pm_cputype; /* what kind of CPU */
           uint32_t        pm_ncpu;    /* max CPU number */
           uint32_t        pm_npmc;    /* #PMCs per CPU */
           uint32_t        pm_nclass;  /* #classes of PMCs */
           struct pmc_classinfo  pm_classes[PMC_CLASS_MAX];
   };
   
   /*
    * OP CONFIGURELOG
    *
    * Configure a log file for writing system-wide statistics to.
    */
   
   struct pmc_op_configurelog {
           int             pm_flags;
           int             pm_logfd;   /* logfile fd (or -1) */
   };
   
   /*
    * OP GETDRIVERSTATS
    *
    * Retrieve pmc(4) driver-wide statistics.
    */
   
   struct pmc_op_getdriverstats {
           int     pm_intr_ignored;        /* #interrupts ignored */
           int     pm_intr_processed;      /* #interrupts processed */
           int     pm_intr_bufferfull;     /* #interrupts with ENOSPC */
           int     pm_syscalls;            /* #syscalls */
           int     pm_syscall_errors;      /* #syscalls with errors */
           int     pm_buffer_requests;     /* #buffer requests */
           int     pm_buffer_requests_failed; /* #failed buffer requests */
           int     pm_log_sweeps;          /* #sample buffer processing passes */
   };
   
   /*
    * OP RELEASE / OP START / OP STOP
    *
    * Simple operations on a PMC id.
    */
   
   struct pmc_op_simple {
           pmc_id_t        pm_pmcid;
   };
   
   /*
    * OP WRITELOG
    *
    * Flush the current log buffer and write 4 bytes of user data to it.
    */
   
   struct pmc_op_writelog {
           uint32_t        pm_userdata;
   };
   
   /*
    * OP GETMSR
    *
    * Retrieve the machine specific address assoicated with the allocated
    * PMC.  This number can be used subsequently with a read-performance-counter
    * instruction.
    */
   
   struct pmc_op_getmsr {
           uint32_t        pm_msr;         /* machine specific address */
           pmc_id_t        pm_pmcid;       /* allocated pmc id */
   };
   
   /*
    * OP GETDYNEVENTINFO
    *
    * Retrieve a PMC dynamic class events list.
    */
   
   struct pmc_dyn_event_descr {
           char            pm_ev_name[PMC_NAME_MAX];
           enum pmc_event  pm_ev_code;
   };
   
   struct pmc_op_getdyneventinfo {
           enum pmc_class                  pm_class;
           unsigned int                    pm_nevent;
           struct pmc_dyn_event_descr      pm_events[PMC_EV_DYN_COUNT];
   };
   
   #ifdef _KERNEL
   
   #include <sys/malloc.h>
   #include <sys/sysctl.h>
   
   #include <machine/frame.h>
   
   #define PMC_HASH_SIZE                           1024
   #define PMC_MTXPOOL_SIZE                        2048
   #define PMC_LOG_BUFFER_SIZE                     4
   #define PMC_NLOGBUFFERS                         1024
   #define PMC_NSAMPLES                            1024
   #define PMC_CALLCHAIN_DEPTH                     32
   
   #define PMC_SYSCTL_NAME_PREFIX "kern." PMC_MODULE_NAME "."
   
   /*
    * Locking keys
    *
    * (b) - pmc_bufferlist_mtx (spin lock)
    * (k) - pmc_kthread_mtx (sleep lock)
    * (o) - po->po_mtx (spin lock)
    */
   
   /*
    * PMC commands
    */
   
   struct pmc_syscall_args {
           register_t      pmop_code;      /* one of PMC_OP_* */
           void            *pmop_data;     /* syscall parameter */
   };
   
   /*
    * Interface to processor specific s1tuff
    */
   
   /*
    * struct pmc_descr
    *
    * Machine independent (i.e., the common parts) of a human readable
    * PMC description.
    */
   
   struct pmc_descr {
           char            pd_name[PMC_NAME_MAX]; /* name */
           uint32_t        pd_caps;        /* capabilities */
           enum pmc_class  pd_class;       /* class of the PMC */
           uint32_t        pd_width;       /* width in bits */
   };
   
   /*
    * struct pmc_target
    *
    * This structure records all the target processes associated with a
    * PMC.
    */
   
   struct pmc_target {
           LIST_ENTRY(pmc_target)  pt_next;
           struct pmc_process      *pt_process; /* target descriptor */
   };
   
   /*
    * struct pmc
    *
    * Describes each allocated PMC.
    *
    * Each PMC has precisely one owner, namely the process that allocated
    * the PMC.
    *
    * A PMC may be attached to multiple target processes.  The
    * 'pm_targets' field links all the target processes being monitored
    * by this PMC.
    *
    * The 'pm_savedvalue' field is protected by a mutex.
    *
    * On a multi-cpu machine, multiple target threads associated with a
    * process-virtual PMC could be concurrently executing on different
    * CPUs.  The 'pm_runcount' field is atomically incremented every time
    * the PMC gets scheduled on a CPU and atomically decremented when it
    * get descheduled.  Deletion of a PMC is only permitted when this
    * field is ''.
    *
    */
   
   struct pmc {
           LIST_HEAD(,pmc_target)  pm_targets;     /* list of target processes */
           LIST_ENTRY(pmc)         pm_next;        /* owner's list */
   
           /*
            * System-wide PMCs are allocated on a CPU and are not moved
            * around.  For system-wide PMCs we record the CPU the PMC was
            * allocated on in the 'CPU' field of the pmc ID.
            *
            * Virtual PMCs run on whichever CPU is currently executing
            * their targets' threads.  For these PMCs we need to save
            * their current PMC counter values when they are taken off
            * CPU.
            */
   
           union {
                   pmc_value_t     pm_savedvalue;  /* Virtual PMCS */
           } pm_gv;
   
           /*
            * For sampling mode PMCs, we keep track of the PMC's "reload
            * count", which is the counter value to be loaded in when
            * arming the PMC for the next counting session.  For counting
            * modes on PMCs that are read-only (e.g., the x86 TSC), we
            * keep track of the initial value at the start of
            * counting-mode operation.
            */
   
           union {
                   pmc_value_t     pm_reloadcount; /* sampling PMC modes */
                   pmc_value_t     pm_initial;     /* counting PMC modes */
           } pm_sc;
   
           uint32_t        pm_stalled;     /* marks stalled sampling PMCs */
           uint32_t        pm_caps;        /* PMC capabilities */
           enum pmc_event  pm_event;       /* event being measured */
           uint32_t        pm_flags;       /* additional flags PMC_F_... */
           struct pmc_owner *pm_owner;     /* owner thread state */
           int             pm_runcount;    /* #cpus currently on */
           enum pmc_state  pm_state;       /* current PMC state */
   
           /*
            * The PMC ID field encodes the row-index for the PMC, its
            * mode, class and the CPU# associated with the PMC.
            */
   
           pmc_id_t        pm_id;          /* allocated PMC id */
   
           /* md extensions */
           union pmc_md_pmc        pm_md;
   };
   
   /*
    * Accessor macros for 'struct pmc'
    */
   
   #define PMC_TO_MODE(P)          PMC_ID_TO_MODE((P)->pm_id)
   #define PMC_TO_CLASS(P)         PMC_ID_TO_CLASS((P)->pm_id)
   #define PMC_TO_ROWINDEX(P)      PMC_ID_TO_ROWINDEX((P)->pm_id)
   #define PMC_TO_CPU(P)           PMC_ID_TO_CPU((P)->pm_id)
   
   
   /*
    * struct pmc_process
    *
    * Record a 'target' process being profiled.
    *
    * The target process being profiled could be different from the owner
    * process which allocated the PMCs.  Each target process descriptor
    * is associated with NHWPMC 'struct pmc *' pointers.  Each PMC at a
    * given hardware row-index 'n' will use slot 'n' of the 'pp_pmcs[]'
    * array.  The size of this structure is thus PMC architecture
    * dependent.
    *
    */
   
   struct pmc_targetstate {
           struct pmc      *pp_pmc;   /* target PMC */
           pmc_value_t     pp_pmcval; /* per-process value */
   };
   
   struct pmc_process {
           LIST_ENTRY(pmc_process) pp_next;        /* hash chain */
           int             pp_refcnt;              /* reference count */
           uint32_t        pp_flags;               /* flags PMC_PP_* */
           struct proc     *pp_proc;               /* target thread */
           struct pmc_targetstate pp_pmcs[];       /* NHWPMCs */
   };
   
   #define PMC_PP_ENABLE_MSR_ACCESS        0x00000001
   
   /*
    * struct pmc_owner
    *
    * We associate a PMC with an 'owner' process.
    *
    * A process can be associated with 0..NCPUS*NHWPMC PMCs during its
    * lifetime, where NCPUS is the numbers of CPUS in the system and
    * NHWPMC is the number of hardware PMCs per CPU.  These are
    * maintained in the list headed by the 'po_pmcs' to save on space.
    *
    */
   
   struct pmc_owner  {
           LIST_ENTRY(pmc_owner)   po_next;        /* hash chain */
           LIST_ENTRY(pmc_owner)   po_ssnext;      /* list of SS PMC owners */
           LIST_HEAD(, pmc)        po_pmcs;        /* owned PMC list */
           TAILQ_HEAD(, pmclog_buffer) po_logbuffers; /* (o) logbuffer list */
           struct mtx              po_mtx;         /* spin lock for (o) */
           struct proc             *po_owner;      /* owner proc */
           uint32_t                po_flags;       /* (k) flags PMC_PO_* */
           struct proc             *po_kthread;    /* (k) helper kthread */
           struct pmclog_buffer    *po_curbuf;     /* current log buffer */
           struct file             *po_file;       /* file reference */
           int                     po_error;       /* recorded error */
           short                   po_sscount;     /* # SS PMCs owned */
           short                   po_logprocmaps; /* global mappings done */
   };
   
   #define PMC_PO_OWNS_LOGFILE             0x00000001 /* has a log file */
   #define PMC_PO_SHUTDOWN                 0x00000010 /* in the process of shutdown */
   #define PMC_PO_INITIAL_MAPPINGS_DONE    0x00000020
   
   /*
    * struct pmc_hw -- describe the state of the PMC hardware
    *
    * When in use, a HW PMC is associated with one allocated 'struct pmc'
    * pointed to by field 'phw_pmc'.  When inactive, this field is NULL.
    *
    * On an SMP box, one or more HW PMC's in process virtual mode with
    * the same 'phw_pmc' could be executing on different CPUs.  In order
    * to handle this case correctly, we need to ensure that only
    * incremental counts get added to the saved value in the associated
    * 'struct pmc'.  The 'phw_save' field is used to keep the saved PMC
    * value at the time the hardware is started during this context
    * switch (i.e., the difference between the new (hardware) count and
    * the saved count is atomically added to the count field in 'struct
    * pmc' at context switch time).
    *
    */
   
   struct pmc_hw {
           uint32_t        phw_state;      /* see PHW_* macros below */
           struct pmc      *phw_pmc;       /* current thread PMC */
   };
   
   #define PMC_PHW_RI_MASK         0x000000FF
   #define PMC_PHW_CPU_SHIFT       8
   #define PMC_PHW_CPU_MASK        0x0000FF00
   #define PMC_PHW_FLAGS_SHIFT     16
   #define PMC_PHW_FLAGS_MASK      0xFFFF0000
   
   #define PMC_PHW_INDEX_TO_STATE(ri)      ((ri) & PMC_PHW_RI_MASK)
   #define PMC_PHW_STATE_TO_INDEX(state)   ((state) & PMC_PHW_RI_MASK)
   #define PMC_PHW_CPU_TO_STATE(cpu)       (((cpu) << PMC_PHW_CPU_SHIFT) & \
           PMC_PHW_CPU_MASK)
   #define PMC_PHW_STATE_TO_CPU(state)     (((state) & PMC_PHW_CPU_MASK) >> \
           PMC_PHW_CPU_SHIFT)
   #define PMC_PHW_FLAGS_TO_STATE(flags)   (((flags) << PMC_PHW_FLAGS_SHIFT) & \
           PMC_PHW_FLAGS_MASK)
   #define PMC_PHW_STATE_TO_FLAGS(state)   (((state) & PMC_PHW_FLAGS_MASK) >> \
           PMC_PHW_FLAGS_SHIFT)
   #define PMC_PHW_FLAG_IS_ENABLED         (PMC_PHW_FLAGS_TO_STATE(0x01))
   #define PMC_PHW_FLAG_IS_SHAREABLE       (PMC_PHW_FLAGS_TO_STATE(0x02))
   
   /*
    * struct pmc_sample
    *
    * Space for N (tunable) PC samples and associated control data.
    */
   
   struct pmc_sample {
           uint16_t                ps_nsamples;    /* callchain depth */
           uint8_t                 ps_cpu;         /* cpu number */
           uint8_t                 ps_flags;       /* other flags */
           pid_t                   ps_pid;         /* process PID or -1 */
           struct thread           *ps_td;         /* which thread */
           struct pmc              *ps_pmc;        /* interrupting PMC */
           uintptr_t               *ps_pc;         /* (const) callchain start */
   };
   
   #define         PMC_SAMPLE_FREE         ((uint16_t) 0)
   #define         PMC_SAMPLE_INUSE        ((uint16_t) 0xFFFF)
   
   struct pmc_samplebuffer {
           struct pmc_sample * volatile ps_read;   /* read pointer */
           struct pmc_sample * volatile ps_write;  /* write pointer */
           uintptr_t               *ps_callchains; /* all saved call chains */
           struct pmc_sample       *ps_fence;      /* one beyond ps_samples[] */
           struct pmc_sample       ps_samples[];   /* array of sample entries */
   };
   
   
   /*
    * struct pmc_cpustate
    *
    * A CPU is modelled as a collection of HW PMCs with space for additional
    * flags.
    */
   
   struct pmc_cpu {
           uint32_t        pc_state;       /* physical cpu number + flags */
           struct pmc_samplebuffer *pc_sb[2]; /* space for samples */
           struct pmc_hw   *pc_hwpmcs[];   /* 'npmc' pointers */
   };
   
   #define PMC_PCPU_CPU_MASK               0x000000FF
   #define PMC_PCPU_FLAGS_MASK             0xFFFFFF00
   #define PMC_PCPU_FLAGS_SHIFT            8
   #define PMC_PCPU_STATE_TO_CPU(S)        ((S) & PMC_PCPU_CPU_MASK)
   #define PMC_PCPU_STATE_TO_FLAGS(S)      (((S) & PMC_PCPU_FLAGS_MASK) >> PMC_PCPU_FLAGS_SHIFT)
   #define PMC_PCPU_FLAGS_TO_STATE(F)      (((F) << PMC_PCPU_FLAGS_SHIFT) & PMC_PCPU_FLAGS_MASK)
   #define PMC_PCPU_CPU_TO_STATE(C)        ((C) & PMC_PCPU_CPU_MASK)
   #define PMC_PCPU_FLAG_HTT               (PMC_PCPU_FLAGS_TO_STATE(0x1))
   
   /*
    * struct pmc_binding
    *
    * CPU binding information.
    */
   
   struct pmc_binding {
           int     pb_bound;       /* is bound? */
           int     pb_cpu;         /* if so, to which CPU */
   };
   
   
   struct pmc_mdep;
   
   /*
    * struct pmc_classdep
    *
    * PMC class-dependent operations.
    */
   struct pmc_classdep {
           uint32_t        pcd_caps;       /* class capabilities */
           enum pmc_class  pcd_class;      /* class id */
           int             pcd_num;        /* number of PMCs */
           int             pcd_ri;         /* row index of the first PMC in class */
           int             pcd_width;      /* width of the PMC */
   
           /* configuring/reading/writing the hardware PMCs */
           int (*pcd_config_pmc)(int _cpu, int _ri, struct pmc *_pm);
           int (*pcd_get_config)(int _cpu, int _ri, struct pmc **_ppm);
           int (*pcd_read_pmc)(int _cpu, int _ri, pmc_value_t *_value);
           int (*pcd_write_pmc)(int _cpu, int _ri, pmc_value_t _value);
   
           /* pmc allocation/release */
           int (*pcd_allocate_pmc)(int _cpu, int _ri, struct pmc *_t,
                   const struct pmc_op_pmcallocate *_a);
           int (*pcd_release_pmc)(int _cpu, int _ri, struct pmc *_pm);
   
           /* starting and stopping PMCs */
           int (*pcd_start_pmc)(int _cpu, int _ri);
           int (*pcd_stop_pmc)(int _cpu, int _ri);
   
           /* description */
           int (*pcd_describe)(int _cpu, int _ri, struct pmc_info *_pi,
                   struct pmc **_ppmc);
   
           /* class-dependent initialization & finalization */
           int (*pcd_pcpu_init)(struct pmc_mdep *_md, int _cpu);
           int (*pcd_pcpu_fini)(struct pmc_mdep *_md, int _cpu);
   
           /* machine-specific interface */
           int (*pcd_get_msr)(int _ri, uint32_t *_msr);
   };
   
   /*
    * struct pmc_mdep
    *
    * Machine dependent bits needed per CPU type.
    */
   
   struct pmc_mdep  {
           uint32_t        pmd_cputype;    /* from enum pmc_cputype */
           uint32_t        pmd_npmc;       /* number of PMCs per CPU */
           uint32_t        pmd_nclass;     /* number of PMC classes present */
   
           /*
            * Machine dependent methods.
            */
   
           /* per-cpu initialization and finalization */
           int (*pmd_pcpu_init)(struct pmc_mdep *_md, int _cpu);
           int (*pmd_pcpu_fini)(struct pmc_mdep *_md, int _cpu);
   
           /* thread context switch in/out */
           int (*pmd_switch_in)(struct pmc_cpu *_p, struct pmc_process *_pp);
           int (*pmd_switch_out)(struct pmc_cpu *_p, struct pmc_process *_pp);
   
           /* handle a PMC interrupt */
           int (*pmd_intr)(int _cpu, struct trapframe *_tf);
   
           /*
            * PMC class dependent information.
            */
           struct pmc_classdep pmd_classdep[];
   };
   
   /*
    * Per-CPU state.  This is an array of 'mp_ncpu' pointers
    * to struct pmc_cpu descriptors.
    */
   
   extern struct pmc_cpu **pmc_pcpu;
   
   /* driver statistics */
   extern struct pmc_op_getdriverstats pmc_stats;
   
   #if     defined(HWPMC_DEBUG)
   #include <sys/ktr.h>
   
   /* debug flags, major flag groups */
   struct pmc_debugflags {
           int     pdb_CPU;
           int     pdb_CSW;
          int     pdb_LOG;
          int     pdb_MDP;
          int     pdb_MOD;
          int     pdb_OWN;
          int     pdb_PMC;
          int     pdb_PRC;
          int     pdb_SAM;
  };
  
  extern struct pmc_debugflags pmc_debugflags;
  
  #define KTR_PMC                 KTR_SUBSYS
  
  #define PMC_DEBUG_STRSIZE               128
  #define PMC_DEBUG_DEFAULT_FLAGS         { 0, 0, 0, 0, 0, 0, 0, 0 }
  
  #define PMCDBG0(M, N, L, F) do {                                        \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR0(KTR_PMC, #M ":" #N ":" #L  ": " F);                \
  } while (0)
  #define PMCDBG1(M, N, L, F, p1) do {                                    \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR1(KTR_PMC, #M ":" #N ":" #L  ": " F, p1);            \
  } while (0)
  #define PMCDBG2(M, N, L, F, p1, p2) do {                                \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR2(KTR_PMC, #M ":" #N ":" #L  ": " F, p1, p2);        \
  } while (0)
  #define PMCDBG3(M, N, L, F, p1, p2, p3) do {                            \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR3(KTR_PMC, #M ":" #N ":" #L  ": " F, p1, p2, p3);    \
  } while (0)
  #define PMCDBG4(M, N, L, F, p1, p2, p3, p4) do {                        \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR4(KTR_PMC, #M ":" #N ":" #L  ": " F, p1, p2, p3, p4);\
  } while (0)
  #define PMCDBG5(M, N, L, F, p1, p2, p3, p4, p5) do {                    \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR5(KTR_PMC, #M ":" #N ":" #L  ": " F, p1, p2, p3, p4, \
                      p5);                                                \
  } while (0)
  #define PMCDBG6(M, N, L, F, p1, p2, p3, p4, p5, p6) do {                \
          if (pmc_debugflags.pdb_ ## M & (1 << PMC_DEBUG_MIN_ ## N))      \
                  CTR6(KTR_PMC, #M ":" #N ":" #L  ": " F, p1, p2, p3, p4, \
                      p5, p6);                                            \
  } while (0)
          
  /* Major numbers */
  #define PMC_DEBUG_MAJ_CPU               0 /* cpu switches */
  #define PMC_DEBUG_MAJ_CSW               1 /* context switches */
  #define PMC_DEBUG_MAJ_LOG               2 /* logging */
  #define PMC_DEBUG_MAJ_MDP               3 /* machine dependent */
  #define PMC_DEBUG_MAJ_MOD               4 /* misc module infrastructure */
  #define PMC_DEBUG_MAJ_OWN               5 /* owner */
  #define PMC_DEBUG_MAJ_PMC               6 /* pmc management */
  #define PMC_DEBUG_MAJ_PRC               7 /* processes */
  #define PMC_DEBUG_MAJ_SAM               8 /* sampling */
  
  /* Minor numbers */
  
  /* Common (8 bits) */
  #define PMC_DEBUG_MIN_ALL               0 /* allocation */
  #define PMC_DEBUG_MIN_REL               1 /* release */
  #define PMC_DEBUG_MIN_OPS               2 /* ops: start, stop, ... */
  #define PMC_DEBUG_MIN_INI               3 /* init */
  #define PMC_DEBUG_MIN_FND               4 /* find */
  
  /* MODULE */
  #define PMC_DEBUG_MIN_PMH              14 /* pmc_hook */
  #define PMC_DEBUG_MIN_PMS              15 /* pmc_syscall */
  
  /* OWN */
  #define PMC_DEBUG_MIN_ORM               8 /* owner remove */
  #define PMC_DEBUG_MIN_OMR               9 /* owner maybe remove */
  
  /* PROCESSES */
  #define PMC_DEBUG_MIN_TLK               8 /* link target */
  #define PMC_DEBUG_MIN_TUL               9 /* unlink target */
  #define PMC_DEBUG_MIN_EXT              10 /* process exit */
  #define PMC_DEBUG_MIN_EXC              11 /* process exec */
  #define PMC_DEBUG_MIN_FRK              12 /* process fork */
  #define PMC_DEBUG_MIN_ATT              13 /* attach/detach */
  #define PMC_DEBUG_MIN_SIG              14 /* signalling */
  
  /* CONTEXT SWITCHES */
  #define PMC_DEBUG_MIN_SWI               8 /* switch in */
  #define PMC_DEBUG_MIN_SWO               9 /* switch out */
  
  /* PMC */
  #define PMC_DEBUG_MIN_REG               8 /* pmc register */
  #define PMC_DEBUG_MIN_ALR               9 /* allocate row */
  
  /* MACHINE DEPENDENT LAYER */
  #define PMC_DEBUG_MIN_REA               8 /* read */
  #define PMC_DEBUG_MIN_WRI               9 /* write */
  #define PMC_DEBUG_MIN_CFG              10 /* config */
  #define PMC_DEBUG_MIN_STA              11 /* start */
  #define PMC_DEBUG_MIN_STO              12 /* stop */
  #define PMC_DEBUG_MIN_INT              13 /* interrupts */
  
  /* CPU */
  #define PMC_DEBUG_MIN_BND               8 /* bind */
  #define PMC_DEBUG_MIN_SEL               9 /* select */
  
  /* LOG */
  #define PMC_DEBUG_MIN_GTB               8 /* get buf */
  #define PMC_DEBUG_MIN_SIO               9 /* schedule i/o */
  #define PMC_DEBUG_MIN_FLS              10 /* flush */
  #define PMC_DEBUG_MIN_SAM              11 /* sample */
  #define PMC_DEBUG_MIN_CLO              12 /* close */
  
  #else
  #define PMCDBG0(M, N, L, F)             /* nothing */
  #define PMCDBG1(M, N, L, F, p1)
  #define PMCDBG2(M, N, L, F, p1, p2)
  #define PMCDBG3(M, N, L, F, p1, p2, p3)
  #define PMCDBG4(M, N, L, F, p1, p2, p3, p4)
  #define PMCDBG5(M, N, L, F, p1, p2, p3, p4, p5)
  #define PMCDBG6(M, N, L, F, p1, p2, p3, p4, p5, p6)
  #endif
  
  /* declare a dedicated memory pool */
  MALLOC_DECLARE(M_PMC);
  
  /*
   * Functions
   */
  
  struct pmc_mdep *pmc_md_initialize(void);       /* MD init function */
  void    pmc_md_finalize(struct pmc_mdep *_md);  /* MD fini function */
  int     pmc_getrowdisp(int _ri);
  int     pmc_process_interrupt(int _cpu, int _soft, struct pmc *_pm,
      struct trapframe *_tf, int _inuserspace);
  int     pmc_save_kernel_callchain(uintptr_t *_cc, int _maxsamples,
      struct trapframe *_tf);
  int     pmc_save_user_callchain(uintptr_t *_cc, int _maxsamples,
      struct trapframe *_tf);
  struct pmc_mdep *pmc_mdep_alloc(int nclasses);
  void pmc_mdep_free(struct pmc_mdep *md);
  #endif /* _KERNEL */
  #endif /* _SYS_PMC_H_ */

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