diff options
Diffstat (limited to 'sys/dev/hwpmc/hwpmc_mod.c')
| -rw-r--r-- | sys/dev/hwpmc/hwpmc_mod.c | 3671 |
1 files changed, 3671 insertions, 0 deletions
diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c new file mode 100644 index 0000000..89b2954 --- /dev/null +++ b/sys/dev/hwpmc/hwpmc_mod.c @@ -0,0 +1,3671 @@ +/*- + * Copyright (c) 2003-2005 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/eventhandler.h> +#include <sys/jail.h> +#include <sys/kernel.h> +#include <sys/limits.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/module.h> +#include <sys/mutex.h> +#include <sys/pmc.h> +#include <sys/pmckern.h> +#include <sys/proc.h> +#include <sys/queue.h> +#include <sys/sched.h> +#include <sys/signalvar.h> +#include <sys/smp.h> +#include <sys/sx.h> +#include <sys/sysctl.h> +#include <sys/sysent.h> +#include <sys/systm.h> + +#include <machine/md_var.h> +#include <machine/pmc_mdep.h> +#include <machine/specialreg.h> + +/* + * Types + */ + +enum pmc_flags { + PMC_FLAG_NONE = 0x00, /* do nothing */ + PMC_FLAG_REMOVE = 0x01, /* atomically remove entry from hash */ + PMC_FLAG_ALLOCATE = 0x02, /* add entry to hash if not found */ +}; + +/* + * The offset in sysent where the syscall is allocated. + */ + +static int pmc_syscall_num = NO_SYSCALL; +struct pmc_cpu **pmc_pcpu; /* per-cpu state */ +pmc_value_t *pmc_pcpu_saved; /* saved PMC values: CSW handling */ + +#define PMC_PCPU_SAVED(C,R) pmc_pcpu_saved[(R) + md->pmd_npmc*(C)] + +struct mtx_pool *pmc_mtxpool; +static int *pmc_pmcdisp; /* PMC row dispositions */ + +#define PMC_ROW_DISP_IS_FREE(R) (pmc_pmcdisp[(R)] == 0) +#define PMC_ROW_DISP_IS_THREAD(R) (pmc_pmcdisp[(R)] > 0) +#define PMC_ROW_DISP_IS_STANDALONE(R) (pmc_pmcdisp[(R)] < 0) + +#define PMC_MARK_ROW_FREE(R) do { \ + pmc_pmcdisp[(R)] = 0; \ +} while (0) + +#define PMC_MARK_ROW_STANDALONE(R) do { \ + KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ + __LINE__)); \ + atomic_add_int(&pmc_pmcdisp[(R)], -1); \ + KASSERT(pmc_pmcdisp[(R)] >= (-mp_ncpus), ("[pmc,%d] row " \ + "disposition error", __LINE__)); \ +} while (0) + +#define PMC_UNMARK_ROW_STANDALONE(R) do { \ + atomic_add_int(&pmc_pmcdisp[(R)], 1); \ + KASSERT(pmc_pmcdisp[(R)] <= 0, ("[pmc,%d] row disposition error", \ + __LINE__)); \ +} while (0) + +#define PMC_MARK_ROW_THREAD(R) do { \ + KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ + __LINE__)); \ + atomic_add_int(&pmc_pmcdisp[(R)], 1); \ +} while (0) + +#define PMC_UNMARK_ROW_THREAD(R) do { \ + atomic_add_int(&pmc_pmcdisp[(R)], -1); \ + KASSERT(pmc_pmcdisp[(R)] >= 0, ("[pmc,%d] row disposition error", \ + __LINE__)); \ +} while (0) + + +/* various event handlers */ +static eventhandler_tag pmc_exit_tag, pmc_fork_tag; + +/* Module statistics */ +struct pmc_op_getdriverstats pmc_stats; + +/* Machine/processor dependent operations */ +struct pmc_mdep *md; + +/* + * Hash tables mapping owner processes and target threads to PMCs. + */ + +struct mtx pmc_processhash_mtx; /* spin mutex */ +static u_long pmc_processhashmask; +static LIST_HEAD(pmc_processhash, pmc_process) *pmc_processhash; + +/* + * Hash table of PMC owner descriptors. This table is protected by + * the shared PMC "sx" lock. + */ + +static u_long pmc_ownerhashmask; +static LIST_HEAD(pmc_ownerhash, pmc_owner) *pmc_ownerhash; + +/* + * Prototypes + */ + +#if DEBUG +static int pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS); +static int pmc_debugflags_parse(char *newstr, char *fence); +#endif + +static int load(struct module *module, int cmd, void *arg); +static int pmc_syscall_handler(struct thread *td, void *syscall_args); +static int pmc_configure_log(struct pmc_owner *po, int logfd); +static void pmc_log_process_exit(struct pmc *pm, struct pmc_process *pp); +static struct pmc *pmc_allocate_pmc_descriptor(void); +static struct pmc *pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, + pmc_id_t pmc); +static void pmc_release_pmc_descriptor(struct pmc *pmc); +static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri); +static struct pmc_process *pmc_find_process_descriptor(struct proc *p, + uint32_t mode); +static void pmc_remove_process_descriptor(struct pmc_process *pp); +static struct pmc_owner *pmc_find_owner_descriptor(struct proc *p); +static int pmc_find_pmc(pmc_id_t pmcid, struct pmc **pm); +static void pmc_remove_owner(struct pmc_owner *po); +static void pmc_maybe_remove_owner(struct pmc_owner *po); +static void pmc_unlink_target_process(struct pmc *pmc, + struct pmc_process *pp); +static void pmc_link_target_process(struct pmc *pm, + struct pmc_process *pp); +static void pmc_unlink_owner(struct pmc *pmc); +static void pmc_cleanup(void); +static void pmc_save_cpu_binding(struct pmc_binding *pb); +static void pmc_restore_cpu_binding(struct pmc_binding *pb); +static void pmc_select_cpu(int cpu); +static void pmc_process_exit(void *arg, struct proc *p); +static void pmc_process_fork(void *arg, struct proc *p1, + struct proc *p2, int n); +static int pmc_attach_one_process(struct proc *p, struct pmc *pm); +static int pmc_attach_process(struct proc *p, struct pmc *pm); +static int pmc_detach_one_process(struct proc *p, struct pmc *pm, + int flags); +static int pmc_detach_process(struct proc *p, struct pmc *pm); +static int pmc_start(struct pmc *pm); +static int pmc_stop(struct pmc *pm); +static int pmc_can_attach(struct pmc *pm, struct proc *p); + +/* + * Kernel tunables and sysctl(8) interface. + */ + +#define PMC_SYSCTL_NAME_PREFIX "kern." PMC_MODULE_NAME "." + +SYSCTL_NODE(_kern, OID_AUTO, hwpmc, CTLFLAG_RW, 0, "HWPMC parameters"); + +#if DEBUG +unsigned int pmc_debugflags = PMC_DEBUG_DEFAULT_FLAGS; +char pmc_debugstr[PMC_DEBUG_STRSIZE]; +TUNABLE_STR(PMC_SYSCTL_NAME_PREFIX "debugflags", pmc_debugstr, + sizeof(pmc_debugstr)); +SYSCTL_PROC(_kern_hwpmc, OID_AUTO, debugflags, + CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_TUN, + 0, 0, pmc_debugflags_sysctl_handler, "A", "debug flags"); +#endif + +/* + * kern.pmc.hashrows -- determines the number of rows in the + * of the hash table used to look up threads + */ + +static int pmc_hashsize = PMC_HASH_SIZE; +TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "hashsize", &pmc_hashsize); +SYSCTL_INT(_kern_hwpmc, OID_AUTO, hashsize, CTLFLAG_TUN|CTLFLAG_RD, + &pmc_hashsize, 0, "rows in hash tables"); + +/* + * kern.pmc.pcpusize -- the size of each per-cpu + * area for collection PC samples. + */ + +static int pmc_pcpu_buffer_size = PMC_PCPU_BUFFER_SIZE; +TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "pcpubuffersize", &pmc_pcpu_buffer_size); +SYSCTL_INT(_kern_hwpmc, OID_AUTO, pcpubuffersize, CTLFLAG_TUN|CTLFLAG_RD, + &pmc_pcpu_buffer_size, 0, "size of per-cpu buffer in 4K pages"); + +/* + * kern.pmc.mtxpoolsize -- number of mutexes in the mutex pool. + */ + +static int pmc_mtxpool_size = PMC_MTXPOOL_SIZE; +TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "mtxpoolsize", &pmc_mtxpool_size); +SYSCTL_INT(_kern_hwpmc, OID_AUTO, mtxpoolsize, CTLFLAG_TUN|CTLFLAG_RD, + &pmc_mtxpool_size, 0, "size of spin mutex pool"); + + + +/* + * security.bsd.unprivileged_syspmcs -- allow non-root processes to + * allocate system-wide PMCs. + * + * Allowing unprivileged processes to allocate system PMCs is convenient + * if system-wide measurements need to be taken concurrently with other + * per-process measurements. This feature is turned off by default. + */ + +SYSCTL_DECL(_security_bsd); + +static int pmc_unprivileged_syspmcs = 0; +TUNABLE_INT("security.bsd.unprivileged_syspmcs", &pmc_unprivileged_syspmcs); +SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_syspmcs, CTLFLAG_RW, + &pmc_unprivileged_syspmcs, 0, + "allow unprivileged process to allocate system PMCs"); + +#if PMC_HASH_USE_CRC32 + +#define PMC_HASH_PTR(P,M) (crc32(&(P), sizeof((P))) & (M)) + +#else /* integer multiplication */ + +#if LONG_BIT == 64 +#define _PMC_HM 11400714819323198486u +#elif LONG_BIT == 32 +#define _PMC_HM 2654435769u +#else +#error Must know the size of 'long' to compile +#endif + +/* + * Hash function. Discard the lower 2 bits of the pointer since + * these are always zero for our uses. The hash multiplier is + * round((2^LONG_BIT) * ((sqrt(5)-1)/2)). + */ + +#define PMC_HASH_PTR(P,M) ((((unsigned long) (P) >> 2) * _PMC_HM) & (M)) + +#endif + +/* + * Syscall structures + */ + +/* The `sysent' for the new syscall */ +static struct sysent pmc_sysent = { + 2, /* sy_narg */ + pmc_syscall_handler /* sy_call */ +}; + +static struct syscall_module_data pmc_syscall_mod = { + load, + NULL, + &pmc_syscall_num, + &pmc_sysent, + { 0, NULL } +}; + +static moduledata_t pmc_mod = { + PMC_MODULE_NAME, + syscall_module_handler, + &pmc_syscall_mod +}; + +DECLARE_MODULE(pmc, pmc_mod, SI_SUB_SMP, SI_ORDER_ANY); +MODULE_VERSION(pmc, PMC_VERSION); + +#if DEBUG +static int +pmc_debugflags_parse(char *newstr, char *fence) +{ + char c, *e, *p, *q; + unsigned int tmpflags; + int level; + char tmpbuf[4]; /* 3 character keyword + '\0' */ + + tmpflags = 0; + level = 0xF; /* max verbosity */ + + p = newstr; + + for (; p < fence && (c = *p);) { + + /* skip separators */ + if (c == ' ' || c == '\t' || c == ',') { + p++; continue; + } + + (void) strlcpy(tmpbuf, p, sizeof(tmpbuf)); + +#define CMP_SET_FLAG_MAJ(S,F) \ + else if (strncmp(tmpbuf, S, 3) == 0) \ + tmpflags |= __PMCDFMAJ(F) + +#define CMP_SET_FLAG_MIN(S,F) \ + else if (strncmp(tmpbuf, S, 3) == 0) \ + tmpflags |= __PMCDFMIN(F) + + if (e - p > 6 && strncmp(p, "level=", 6) == 0) { + p += 6; /* skip over keyword */ + level = strtoul(p, &q, 16); + } + CMP_SET_FLAG_MAJ("mod", MOD); + CMP_SET_FLAG_MAJ("pmc", PMC); + CMP_SET_FLAG_MAJ("ctx", CTX); + CMP_SET_FLAG_MAJ("own", OWN); + CMP_SET_FLAG_MAJ("prc", PRC); + CMP_SET_FLAG_MAJ("mdp", MDP); + CMP_SET_FLAG_MAJ("cpu", CPU); + + CMP_SET_FLAG_MIN("all", ALL); + CMP_SET_FLAG_MIN("rel", REL); + CMP_SET_FLAG_MIN("ops", OPS); + CMP_SET_FLAG_MIN("ini", INI); + CMP_SET_FLAG_MIN("fnd", FND); + CMP_SET_FLAG_MIN("pmh", PMH); + CMP_SET_FLAG_MIN("pms", PMS); + CMP_SET_FLAG_MIN("orm", ORM); + CMP_SET_FLAG_MIN("omr", OMR); + CMP_SET_FLAG_MIN("tlk", TLK); + CMP_SET_FLAG_MIN("tul", TUL); + CMP_SET_FLAG_MIN("ext", EXT); + CMP_SET_FLAG_MIN("exc", EXC); + CMP_SET_FLAG_MIN("frk", FRK); + CMP_SET_FLAG_MIN("att", ATT); + CMP_SET_FLAG_MIN("swi", SWI); + CMP_SET_FLAG_MIN("swo", SWO); + CMP_SET_FLAG_MIN("reg", REG); + CMP_SET_FLAG_MIN("alr", ALR); + CMP_SET_FLAG_MIN("rea", REA); + CMP_SET_FLAG_MIN("wri", WRI); + CMP_SET_FLAG_MIN("cfg", CFG); + CMP_SET_FLAG_MIN("sta", STA); + CMP_SET_FLAG_MIN("sto", STO); + CMP_SET_FLAG_MIN("bnd", BND); + CMP_SET_FLAG_MIN("sel", SEL); + else /* unrecognized keyword */ + return EINVAL; + + p += 4; /* skip keyword and separator */ + } + + pmc_debugflags = (tmpflags|level); + + return 0; +} + +static int +pmc_debugflags_sysctl_handler(SYSCTL_HANDLER_ARGS) +{ + char *fence, *newstr; + int error; + unsigned int n; + + (void) arg1; (void) arg2; /* unused parameters */ + + n = sizeof(pmc_debugstr); + MALLOC(newstr, char *, n, M_PMC, M_ZERO|M_WAITOK); + (void) strlcpy(newstr, pmc_debugstr, sizeof(pmc_debugstr)); + + error = sysctl_handle_string(oidp, newstr, n, req); + + /* if there is a new string, parse and copy it */ + if (error == 0 && req->newptr != NULL) { + fence = newstr + (n < req->newlen ? n : req->newlen); + if ((error = pmc_debugflags_parse(newstr, fence)) == 0) + (void) strlcpy(pmc_debugstr, newstr, + sizeof(pmc_debugstr)); + } + + FREE(newstr, M_PMC); + + return error; +} +#endif + +/* + * Concurrency Control + * + * The driver manages the following data structures: + * + * - target process descriptors, one per target process + * - owner process descriptors (and attached lists), one per owner process + * - lookup hash tables for owner and target processes + * - PMC descriptors (and attached lists) + * - per-cpu hardware state + * - the 'hook' variable through which the kernel calls into + * this module + * - the machine hardware state (managed by the MD layer) + * + * These data structures are accessed from: + * + * - thread context-switch code + * - interrupt handlers (possibly on multiple cpus) + * - kernel threads on multiple cpus running on behalf of user + * processes doing system calls + * - this driver's private kernel threads + * + * = Locks and Locking strategy = + * + * The driver uses four locking strategies for its operation: + * + * - There is a 'global' SX lock "pmc_sx" that is used to protect + * the its 'meta-data'. + * + * Calls into the module (via syscall() or by the kernel) start with + * this lock being held in exclusive mode. Depending on the requested + * operation, the lock may be downgraded to 'shared' mode to allow + * more concurrent readers into the module. + * + * This SX lock is held in exclusive mode for any operations that + * modify the linkages between the driver's internal data structures. + * + * The 'pmc_hook' function pointer is also protected by this lock. + * It is only examined with the sx lock held in exclusive mode. The + * kernel module is allowed to be unloaded only with the sx lock + * held in exclusive mode. In normal syscall handling, after + * acquiring the pmc_sx lock we first check that 'pmc_hook' is + * non-null before proceeding. This prevents races between the + * thread unloading the module and other threads seeking to use the + * module. + * + * - Lookups of target process structures and owner process structures + * cannot use the global "pmc_sx" SX lock because these lookups need + * to happen during context switches and in other critical sections + * where sleeping is not allowed. We protect these lookup tables + * with their own private spin-mutexes, "pmc_processhash_mtx" and + * "pmc_ownerhash_mtx". These are 'leaf' mutexes, in that no other + * lock is acquired with these locks held. + * + * - Interrupt handlers work in a lock free manner. At interrupt + * time, handlers look at the PMC pointer (phw->phw_pmc) configured + * when the PMC was started. If this pointer is NULL, the interrupt + * is ignored after updating driver statistics. We ensure that this + * pointer is set (using an atomic operation if necessary) before the + * PMC hardware is started. Conversely, this pointer is unset atomically + * only after the PMC hardware is stopped. + * + * We ensure that everything needed for the operation of an + * interrupt handler is available without it needing to acquire any + * locks. We also ensure that a PMC's software state is destroyed only + * after the PMC is taken off hardware (on all CPUs). + * + * - Context-switch handling with process-private PMCs needs more + * care. + * + * A given process may be the target of multiple PMCs. For example, + * PMCATTACH and PMCDETACH may be requested by a process on one CPU + * while the target process is running on another. A PMC could also + * be getting released because its owner is exiting. We tackle + * these situations in the following manner: + * + * - each target process structure 'pmc_process' has an array + * of 'struct pmc *' pointers, one for each hardware PMC. + * + * - At context switch IN time, each "target" PMC in RUNNING state + * gets started on hardware and a pointer to each PMC is copied into + * the per-cpu phw array. The 'runcount' for the PMC is + * incremented. + * + * - At context switch OUT time, all process-virtual PMCs are stopped + * on hardware. The saved value is added to the PMCs value field + * only if the PMC is in a non-deleted state (the PMCs state could + * have changed during the current time slice). + * + * Note that since in-between a switch IN on a processor and a switch + * OUT, the PMC could have been released on another CPU. Therefore + * context switch OUT always looks at the hardware state to turn + * OFF PMCs and will update a PMC's saved value only if reachable + * from the target process record. + * + * - OP PMCRELEASE could be called on a PMC at any time (the PMC could + * be attached to many processes at the time of the call and could + * be active on multiple CPUs). + * + * We prevent further scheduling of the PMC by marking it as in + * state 'DELETED'. If the runcount of the PMC is non-zero then + * this PMC is currently running on a CPU somewhere. The thread + * doing the PMCRELEASE operation waits by repeatedly doing an + * tsleep() till the runcount comes to zero. + * + */ + +/* + * save the cpu binding of the current kthread + */ + +static void +pmc_save_cpu_binding(struct pmc_binding *pb) +{ + PMCDBG(CPU,BND,2, "%s", "save-cpu"); + mtx_lock_spin(&sched_lock); + pb->pb_bound = sched_is_bound(curthread); + pb->pb_cpu = curthread->td_oncpu; + mtx_unlock_spin(&sched_lock); + PMCDBG(CPU,BND,2, "save-cpu cpu=%d", pb->pb_cpu); +} + +/* + * restore the cpu binding of the current thread + */ + +static void +pmc_restore_cpu_binding(struct pmc_binding *pb) +{ + PMCDBG(CPU,BND,2, "restore-cpu curcpu=%d restore=%d", + curthread->td_oncpu, pb->pb_cpu); + mtx_lock_spin(&sched_lock); + if (pb->pb_bound) + sched_bind(curthread, pb->pb_cpu); + else + sched_unbind(curthread); + mtx_unlock_spin(&sched_lock); + PMCDBG(CPU,BND,2, "%s", "restore-cpu done"); +} + +/* + * move execution over the specified cpu and bind it there. + */ + +static void +pmc_select_cpu(int cpu) +{ + KASSERT(cpu >= 0 && cpu < mp_ncpus, + ("[pmc,%d] bad cpu number %d", __LINE__, cpu)); + + /* never move to a disabled CPU */ + KASSERT(pmc_cpu_is_disabled(cpu) == 0, ("[pmc,%d] selecting " + "disabled CPU %d", __LINE__, cpu)); + + PMCDBG(CPU,SEL,2, "select-cpu cpu=%d", cpu); + mtx_lock_spin(&sched_lock); + sched_bind(curthread, cpu); + mtx_unlock_spin(&sched_lock); + + KASSERT(curthread->td_oncpu == cpu, + ("[pmc,%d] CPU not bound [cpu=%d, curr=%d]", __LINE__, + cpu, curthread->td_oncpu)); + + PMCDBG(CPU,SEL,2, "select-cpu cpu=%d ok", cpu); +} + +/* + * Update the per-pmc histogram + */ + +void +pmc_update_histogram(struct pmc_hw *phw, uintptr_t pc) +{ + (void) phw; + (void) pc; +} + +/* + * Send a signal to a process. This is meant to be invoked from an + * interrupt handler. + */ + +void +pmc_send_signal(struct pmc *pmc) +{ + (void) pmc; /* shutup gcc */ + +#if 0 + struct proc *proc; + struct thread *td; + + KASSERT(pmc->pm_owner != NULL, + ("[pmc,%d] No owner for PMC", __LINE__)); + + KASSERT((pmc->pm_owner->po_flags & PMC_FLAG_IS_OWNER) && + (pmc->pm_owner->po_flags & PMC_FLAG_HAS_TS_PMC), + ("[pmc,%d] interrupting PMC owner has wrong flags 0x%x", + __LINE__, pmc->pm_owner->po_flags)); + + proc = pmc->pm_owner->po_owner; + + KASSERT(curthread->td_proc == proc, + ("[pmc,%d] interruping the wrong thread (owner %p, " + "cur %p)", __LINE__, (void *) proc, curthread->td_proc)); + + mtx_lock_spin(&sched_lock); + td = TAILQ_FIRST(&proc->p_threads); + mtx_unlock_spin(&sched_lock); + /* XXX RACE HERE: can 'td' disappear now? */ + trapsignal(td, SIGPROF, 0); + /* XXX rework this to use the regular 'psignal' interface from a + helper thread */ +#endif + +} + +/* + * remove an process owning PMCs + */ + +void +pmc_remove_owner(struct pmc_owner *po) +{ + struct pmc_list *pl, *tmp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + PMCDBG(OWN,ORM,1, "remove-owner po=%p", po); + + /* Remove descriptor from the owner hash table */ + LIST_REMOVE(po, po_next); + + /* pass 1: release all owned PMC descriptors */ + LIST_FOREACH_SAFE(pl, &po->po_pmcs, pl_next, tmp) { + + PMCDBG(OWN,ORM,2, "pl=%p pmc=%p", pl, pl->pl_pmc); + + /* remove the associated PMC descriptor, if present */ + if (pl->pl_pmc) + pmc_release_pmc_descriptor(pl->pl_pmc); + + /* remove the linked list entry */ + LIST_REMOVE(pl, pl_next); + FREE(pl, M_PMC); + } + + /* pass 2: delete the pmc_list chain */ + LIST_FOREACH_SAFE(pl, &po->po_pmcs, pl_next, tmp) { + KASSERT(pl->pl_pmc == NULL, + ("[pmc,%d] non-null pmc pointer", __LINE__)); + LIST_REMOVE(pl, pl_next); + FREE(pl, M_PMC); + } + + KASSERT(LIST_EMPTY(&po->po_pmcs), + ("[pmc,%d] PMC list not empty", __LINE__)); + + + /* + * If this process owns a log file used for system wide logging, + * remove the log file. + * + * XXX rework needed. + */ + + if (po->po_flags & PMC_FLAG_OWNS_LOGFILE) + pmc_configure_log(po, -1); + +} + +/* + * remove an owner process record if all conditions are met. + */ + +static void +pmc_maybe_remove_owner(struct pmc_owner *po) +{ + + PMCDBG(OWN,OMR,1, "maybe-remove-owner po=%p", po); + + /* + * Remove owner record if + * - this process does not own any PMCs + * - this process has not allocated a system-wide sampling buffer + */ + + if (LIST_EMPTY(&po->po_pmcs) && + ((po->po_flags & PMC_FLAG_OWNS_LOGFILE) == 0)) { + pmc_remove_owner(po); + FREE(po, M_PMC); + } +} + +/* + * Add an association between a target process and a PMC. + */ + +static void +pmc_link_target_process(struct pmc *pm, struct pmc_process *pp) +{ + int ri; + struct pmc_target *pt; + + sx_assert(&pmc_sx, SX_XLOCKED); + + KASSERT(pm != NULL && pp != NULL, + ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); + + KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < ((int) md->pmd_npmc - 1), + ("[pmc,%d] Illegal reference count %d for process record %p", + __LINE__, pp->pp_refcnt, (void *) pp)); + + ri = pm->pm_rowindex; + + PMCDBG(PRC,TLK,1, "link-target pmc=%p ri=%d pmc-process=%p", + pm, ri, pp); + +#if DEBUG + LIST_FOREACH(pt, &pm->pm_targets, pt_next) + if (pt->pt_process == pp) + KASSERT(0, ("[pmc,%d] pp %p already in pmc %p targets", + __LINE__, pp, pm)); +#endif + + MALLOC(pt, struct pmc_target *, sizeof(struct pmc_target), + M_PMC, M_ZERO|M_WAITOK); + + pt->pt_process = pp; + + LIST_INSERT_HEAD(&pm->pm_targets, pt, pt_next); + + atomic_store_rel_ptr(&pp->pp_pmcs[ri].pp_pmc, pm); + + pp->pp_refcnt++; + +} + +/* + * Removes the association between a target process and a PMC. + */ + +static void +pmc_unlink_target_process(struct pmc *pm, struct pmc_process *pp) +{ + int ri; + struct pmc_target *ptgt; + + sx_assert(&pmc_sx, SX_XLOCKED); + + KASSERT(pm != NULL && pp != NULL, + ("[pmc,%d] Null pm %p or pp %p", __LINE__, pm, pp)); + + KASSERT(pp->pp_refcnt >= 1 && pp->pp_refcnt < (int) md->pmd_npmc, + ("[pmc,%d] Illegal ref count %d on process record %p", + __LINE__, pp->pp_refcnt, (void *) pp)); + + ri = pm->pm_rowindex; + + PMCDBG(PRC,TUL,1, "unlink-target pmc=%p ri=%d pmc-process=%p", + pm, ri, pp); + + KASSERT(pp->pp_pmcs[ri].pp_pmc == pm, + ("[pmc,%d] PMC ri %d mismatch pmc %p pp->[ri] %p", __LINE__, + ri, pm, pp->pp_pmcs[ri].pp_pmc)); + + pp->pp_pmcs[ri].pp_pmc = NULL; + pp->pp_pmcs[ri].pp_pmcval = (pmc_value_t) 0; + + pp->pp_refcnt--; + + /* Remove the target process from the PMC structure */ + LIST_FOREACH(ptgt, &pm->pm_targets, pt_next) + if (ptgt->pt_process == pp) + break; + + KASSERT(ptgt != NULL, ("[pmc,%d] process %p (pp: %p) not found " + "in pmc %p", __LINE__, pp->pp_proc, pp, pm)); + + PMCDBG(PRC,TUL,4, "unlink ptgt=%p", ptgt); + + LIST_REMOVE(ptgt, pt_next); + FREE(ptgt, M_PMC); +} + +/* + * Remove PMC descriptor 'pmc' from the owner descriptor. + */ + +void +pmc_unlink_owner(struct pmc *pm) +{ + struct pmc_list *pl, *tmp; + struct pmc_owner *po; + +#if DEBUG + KASSERT(LIST_EMPTY(&pm->pm_targets), + ("[pmc,%d] unlinking PMC with targets", __LINE__)); +#endif + + po = pm->pm_owner; + + KASSERT(po != NULL, ("[pmc,%d] No owner for PMC", __LINE__)); + + LIST_FOREACH_SAFE(pl, &po->po_pmcs, pl_next, tmp) { + if (pl->pl_pmc == pm) { + pl->pl_pmc = NULL; + pm->pm_owner = NULL; + return; + } + } + + KASSERT(0, ("[pmc,%d] couldn't find pmc in owner list", __LINE__)); +} + +/* + * Check if PMC 'pm' may be attached to target process 't'. + */ + +static int +pmc_can_attach(struct pmc *pm, struct proc *t) +{ + struct proc *o; /* pmc owner */ + struct ucred *oc, *tc; /* owner, target credentials */ + int decline_attach, i; + + /* + * A PMC's owner can always attach that PMC to itself. + */ + + if ((o = pm->pm_owner->po_owner) == t) + return 0; + + PROC_LOCK(o); + oc = o->p_ucred; + crhold(oc); + PROC_UNLOCK(o); + + PROC_LOCK(t); + tc = t->p_ucred; + crhold(tc); + PROC_UNLOCK(t); + + /* + * The effective uid of the PMC owner should match at least one + * of the {effective,real,saved} uids of the target process. + */ + + decline_attach = oc->cr_uid != tc->cr_uid && + oc->cr_uid != tc->cr_svuid && + oc->cr_uid != tc->cr_ruid; + + /* + * Every one of the target's group ids, must be in the owner's + * group list. + */ + for (i = 0; !decline_attach && i < tc->cr_ngroups; i++) + decline_attach = !groupmember(tc->cr_groups[i], oc); + + /* check the read and saved gids too */ + if (decline_attach == 0) + decline_attach = !groupmember(tc->cr_rgid, oc) || + !groupmember(tc->cr_svgid, oc); + + crfree(tc); + crfree(oc); + + return !decline_attach; +} + +/* + * Attach a process to a PMC. + */ + +static int +pmc_attach_one_process(struct proc *p, struct pmc *pm) +{ + int ri; + struct pmc_process *pp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + PMCDBG(PRC,ATT,2, "attach-one pm=%p ri=%d proc=%p (%d, %s)", pm, + pm->pm_rowindex, p, p->p_pid, p->p_comm); + + /* + * Locate the process descriptor corresponding to process 'p', + * allocating space as needed. + * + * Verify that rowindex 'pm_rowindex' is free in the process + * descriptor. + * + * If not, allocate space for a descriptor and link the + * process descriptor and PMC. + */ + + ri = pm->pm_rowindex; + + if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_ALLOCATE)) == NULL) + return ENOMEM; + + if (pp->pp_pmcs[ri].pp_pmc == pm) /* already present at slot [ri] */ + return EEXIST; + + if (pp->pp_pmcs[ri].pp_pmc != NULL) + return EBUSY; + + pmc_link_target_process(pm, pp); + + /* mark process as using HWPMCs */ + PROC_LOCK(p); + p->p_flag |= P_HWPMC; + PROC_UNLOCK(p); + + return 0; +} + +/* + * Attach a process and optionally its children + */ + +static int +pmc_attach_process(struct proc *p, struct pmc *pm) +{ + int error; + struct proc *top; + + sx_assert(&pmc_sx, SX_XLOCKED); + + PMCDBG(PRC,ATT,1, "attach pm=%p ri=%d proc=%p (%d, %s)", pm, + pm->pm_rowindex, p, p->p_pid, p->p_comm); + + if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) + return pmc_attach_one_process(p, pm); + + /* + * Traverse all child processes, attaching them to + * this PMC. + */ + + sx_slock(&proctree_lock); + + top = p; + + for (;;) { + if ((error = pmc_attach_one_process(p, pm)) != 0) + break; + if (!LIST_EMPTY(&p->p_children)) + p = LIST_FIRST(&p->p_children); + else for (;;) { + if (p == top) + goto done; + if (LIST_NEXT(p, p_sibling)) { + p = LIST_NEXT(p, p_sibling); + break; + } + p = p->p_pptr; + } + } + + if (error) + (void) pmc_detach_process(top, pm); + + done: + sx_sunlock(&proctree_lock); + return error; +} + +/* + * Detach a process from a PMC. If there are no other PMCs tracking + * this process, remove the process structure from its hash table. If + * 'flags' contains PMC_FLAG_REMOVE, then free the process structure. + */ + +static int +pmc_detach_one_process(struct proc *p, struct pmc *pm, int flags) +{ + int ri; + struct pmc_process *pp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + KASSERT(pm != NULL, + ("[pmc,%d] null pm pointer", __LINE__)); + + PMCDBG(PRC,ATT,2, "detach-one pm=%p ri=%d proc=%p (%d, %s) flags=0x%x", + pm, pm->pm_rowindex, p, p->p_pid, p->p_comm, flags); + + ri = pm->pm_rowindex; + + if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) + return ESRCH; + + if (pp->pp_pmcs[ri].pp_pmc != pm) + return EINVAL; + + pmc_unlink_target_process(pm, pp); + + /* + * If there are no PMCs targetting this process, we remove its + * descriptor from the target hash table and unset the P_HWPMC + * flag in the struct proc. + */ + + KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, + ("[pmc,%d] Illegal refcnt %d for process struct %p", + __LINE__, pp->pp_refcnt, pp)); + + if (pp->pp_refcnt != 0) /* still a target of some PMC */ + return 0; + + pmc_remove_process_descriptor(pp); + + if (flags & PMC_FLAG_REMOVE) + FREE(pp, M_PMC); + + PROC_LOCK(p); + p->p_flag &= ~P_HWPMC; + PROC_UNLOCK(p); + + return 0; +} + +/* + * Detach a process and optionally its descendants from a PMC. + */ + +static int +pmc_detach_process(struct proc *p, struct pmc *pm) +{ + struct proc *top; + + sx_assert(&pmc_sx, SX_XLOCKED); + + PMCDBG(PRC,ATT,1, "detach pm=%p ri=%d proc=%p (%d, %s)", pm, + pm->pm_rowindex, p, p->p_pid, p->p_comm); + + if ((pm->pm_flags & PMC_F_DESCENDANTS) == 0) + return pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); + + /* + * Traverse all children, detaching them from this PMC. We + * ignore errors since we could be detaching a PMC from a + * partially attached proc tree. + */ + + sx_slock(&proctree_lock); + + top = p; + + for (;;) { + (void) pmc_detach_one_process(p, pm, PMC_FLAG_REMOVE); + + if (!LIST_EMPTY(&p->p_children)) + p = LIST_FIRST(&p->p_children); + else for (;;) { + if (p == top) + goto done; + if (LIST_NEXT(p, p_sibling)) { + p = LIST_NEXT(p, p_sibling); + break; + } + p = p->p_pptr; + } + } + + done: + sx_sunlock(&proctree_lock); + return 0; +} + +/* + * The 'hook' invoked from the kernel proper + */ + + +#if DEBUG +const char *pmc_hooknames[] = { + "", + "EXIT", + "EXEC", + "FORK", + "CSW-IN", + "CSW-OUT" +}; +#endif + +static int +pmc_hook_handler(struct thread *td, int function, void *arg) +{ + + KASSERT(td->td_proc->p_flag & P_HWPMC, + ("[pmc,%d] unregistered thread called pmc_hook()", __LINE__)); + + PMCDBG(MOD,PMH,1, "hook td=%p func=%d \"%s\" arg=%p", td, function, + pmc_hooknames[function], arg); + + switch (function) + { + + /* + * Process exit. + * + * Remove this process from all hash tables. If this process + * owned any PMCs, turn off those PMCs and deallocate them, + * removing any associations with target processes. + * + * This function will be called by the last 'thread' of a + * process. + * + */ + + case PMC_FN_PROCESS_EXIT: /* release PMCs */ + { + int cpu; + unsigned int ri; + struct pmc *pm; + struct pmc_hw *phw; + struct pmc_process *pp; + struct pmc_owner *po; + struct proc *p; + pmc_value_t newvalue, tmp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + p = (struct proc *) arg; + + /* + * Since this code is invoked by the last thread in an + * exiting process, we would have context switched IN + * at some prior point. Kernel mode context switches + * may happen any time, so we want to disable a context + * switch OUT till we get any PMCs targetting this + * process off the hardware. + * + * We also need to atomically remove this process' + * entry from our target process hash table, using + * PMC_FLAG_REMOVE. + */ + + PMCDBG(PRC,EXT,1, "process-exit proc=%p (%d, %s)", p, p->p_pid, + p->p_comm); + + critical_enter(); /* no preemption */ + + cpu = curthread->td_oncpu; + + if ((pp = pmc_find_process_descriptor(p, + PMC_FLAG_REMOVE)) != NULL) { + + PMCDBG(PRC,EXT,2, + "process-exit proc=%p pmc-process=%p", p, pp); + + /* + * This process could the target of some PMCs. + * Such PMCs will thus be running on currently + * executing CPU at this point in the code + * since we've disallowed context switches. + * We need to turn these PMCs off like we + * would do at context switch OUT time. + */ + + for (ri = 0; ri < md->pmd_npmc; ri++) { + + /* + * Pick up the pmc pointer from hardware + * state similar to the CSW_OUT code. + */ + + phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; + pm = phw->phw_pmc; + + PMCDBG(PRC,EXT,2, "ri=%d pm=%p", ri, pm); + + if (pm == NULL || + !PMC_IS_VIRTUAL_MODE(pm->pm_mode)) + continue; + + PMCDBG(PRC,EXT,2, "ppmcs[%d]=%p pm=%p " + "state=%d", ri, pp->pp_pmcs[ri].pp_pmc, + pm, pm->pm_state); + + KASSERT(pm->pm_rowindex == ri, + ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", + __LINE__, pm->pm_rowindex, ri)); + + KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, + ("[pmc,%d] pm %p != pp_pmcs[%d] %p", + __LINE__, pm, ri, + pp->pp_pmcs[ri].pp_pmc)); + + (void) md->pmd_stop_pmc(cpu, ri); + + KASSERT(pm->pm_runcount > 0, + ("[pmc,%d] bad runcount ri %d rc %d", + __LINE__, ri, pm->pm_runcount)); + + if (pm->pm_state == PMC_STATE_RUNNING) { + md->pmd_read_pmc(cpu, ri, &newvalue); + tmp = newvalue - + PMC_PCPU_SAVED(cpu,ri); + + mtx_pool_lock_spin(pmc_mtxpool, pm); + pm->pm_gv.pm_savedvalue += tmp; + pp->pp_pmcs[ri].pp_pmcval += tmp; + mtx_pool_unlock_spin(pmc_mtxpool, pm); + } + + KASSERT((int) pm->pm_runcount >= 0, + ("[pmc,%d] runcount is %d", __LINE__, ri)); + + atomic_subtract_rel_32(&pm->pm_runcount,1); + (void) md->pmd_config_pmc(cpu, ri, NULL); + } + critical_exit(); /* ok to be pre-empted now */ + + /* + * Unlink this process from the PMCs that are + * targetting it. Log value at exit() time if + * requested. + */ + + for (ri = 0; ri < md->pmd_npmc; ri++) + if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) { + if (pm->pm_flags & + PMC_F_LOG_TC_PROCEXIT) + pmc_log_process_exit(pm, pp); + pmc_unlink_target_process(pm, pp); + } + + FREE(pp, M_PMC); + + } else + critical_exit(); /* pp == NULL */ + + /* + * If the process owned PMCs, free them up and free up + * memory. + */ + + if ((po = pmc_find_owner_descriptor(p)) != NULL) { + pmc_remove_owner(po); + FREE(po, M_PMC); + } + + } + break; + + /* + * Process exec() + */ + + case PMC_FN_PROCESS_EXEC: + { + int *credentials_changed; + unsigned int ri; + struct pmc *pm; + struct proc *p; + struct pmc_owner *po; + struct pmc_process *pp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + /* + * PMCs are not inherited across an exec(): remove any + * PMCs that this process is the owner of. + */ + + p = td->td_proc; + + if ((po = pmc_find_owner_descriptor(p)) != NULL) { + pmc_remove_owner(po); + FREE(po, M_PMC); + } + + /* + * If this process is the target of a PMC, check if the new + * credentials are compatible with the owner's permissions. + */ + + if ((pp = pmc_find_process_descriptor(p, 0)) == NULL) + break; + + credentials_changed = arg; + + PMCDBG(PRC,EXC,1, "exec proc=%p (%d, %s) cred-changed=%d", + p, p->p_pid, p->p_comm, *credentials_changed); + + if (*credentials_changed == 0) /* credentials didn't change */ + break; + + /* + * If the newly exec()'ed process has a different credential + * than before, allow it to be the target of a PMC only if + * the PMC's owner has sufficient priviledge. + */ + + for (ri = 0; ri < md->pmd_npmc; ri++) + if ((pm = pp->pp_pmcs[ri].pp_pmc) != NULL) + if (pmc_can_attach(pm, td->td_proc) != 0) + pmc_detach_one_process(td->td_proc, + pm, PMC_FLAG_NONE); + + KASSERT(pp->pp_refcnt >= 0 && pp->pp_refcnt < (int) md->pmd_npmc, + ("[pmc,%d] Illegal ref count %d on pp %p", __LINE__, + pp->pp_refcnt, pp)); + + /* + * If this process is no longer the target of any + * PMCs, we can remove the process entry and free + * up space. + */ + + if (pp->pp_refcnt == 0) { + pmc_remove_process_descriptor(pp); + FREE(pp, M_PMC); + } + } + break; + + /* + * Process fork() + */ + + case PMC_FN_PROCESS_FORK: + { + unsigned int ri; + uint32_t do_descendants; + struct pmc *pm; + struct pmc_process *ppnew, *ppold; + struct proc *newproc; + + sx_assert(&pmc_sx, SX_XLOCKED); + + newproc = (struct proc *) arg; + + PMCDBG(PMC,FRK,2, "process-fork p1=%p p2=%p", + curthread->td_proc, newproc); + /* + * If the parent process (curthread->td_proc) is a + * target of any PMCs, look for PMCs that are to be + * inherited, and link these into the new process + * descriptor. + */ + + if ((ppold = pmc_find_process_descriptor( + curthread->td_proc, PMC_FLAG_NONE)) == NULL) + break; + + do_descendants = 0; + for (ri = 0; ri < md->pmd_npmc; ri++) + if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL) + do_descendants |= + pm->pm_flags & PMC_F_DESCENDANTS; + if (do_descendants == 0) /* nothing to do */ + break; + + if ((ppnew = pmc_find_process_descriptor(newproc, + PMC_FLAG_ALLOCATE)) == NULL) + return ENOMEM; + + /* + * Run through all PMCs targeting the old process and + * attach them to the new process. + */ + + for (ri = 0; ri < md->pmd_npmc; ri++) + if ((pm = ppold->pp_pmcs[ri].pp_pmc) != NULL && + pm->pm_flags & PMC_F_DESCENDANTS) + pmc_link_target_process(pm, ppnew); + + /* + * Now mark the new process as being tracked by this + * driver. + */ + + PROC_LOCK(newproc); + newproc->p_flag |= P_HWPMC; + PROC_UNLOCK(newproc); + + } + break; + + /* + * Thread context switch IN + */ + + case PMC_FN_CSW_IN: + { + int cpu; + unsigned int ri; + struct pmc *pm; + struct proc *p; + struct pmc_cpu *pc; + struct pmc_hw *phw; + struct pmc_process *pp; + pmc_value_t newvalue; + + p = td->td_proc; + + if ((pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE)) == NULL) + break; + + KASSERT(pp->pp_proc == td->td_proc, + ("[pmc,%d] not my thread state", __LINE__)); + + critical_enter(); /* no preemption on this CPU */ + + cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ + + PMCDBG(CTX,SWI,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, + p->p_pid, p->p_comm, pp); + + KASSERT(cpu >= 0 && cpu < mp_ncpus, + ("[pmc,%d] wierd CPU id %d", __LINE__, cpu)); + + pc = pmc_pcpu[cpu]; + + for (ri = 0; ri < md->pmd_npmc; ri++) { + + if ((pm = pp->pp_pmcs[ri].pp_pmc) == NULL) + continue; + + KASSERT(PMC_IS_VIRTUAL_MODE(pm->pm_mode), + ("[pmc,%d] Target PMC in non-virtual mode (%d)", + __LINE__, pm->pm_mode)); + + KASSERT(pm->pm_rowindex == ri, + ("[pmc,%d] Row index mismatch pmc %d != ri %d", + __LINE__, pm->pm_rowindex, ri)); + + /* + * Only PMCs that are marked as 'RUNNING' need + * be placed on hardware. + */ + + if (pm->pm_state != PMC_STATE_RUNNING) + continue; + + /* increment PMC runcount */ + atomic_add_rel_32(&pm->pm_runcount, 1); + + /* configure the HWPMC we are going to use. */ + md->pmd_config_pmc(cpu, ri, pm); + + phw = pc->pc_hwpmcs[ri]; + + KASSERT(phw != NULL, + ("[pmc,%d] null hw pointer", __LINE__)); + + KASSERT(phw->phw_pmc == pm, + ("[pmc,%d] hw->pmc %p != pmc %p", __LINE__, + phw->phw_pmc, pm)); + + /* write out saved value and start the PMC */ + mtx_pool_lock_spin(pmc_mtxpool, pm); + newvalue = PMC_PCPU_SAVED(cpu, ri) = + pm->pm_gv.pm_savedvalue; + mtx_pool_unlock_spin(pmc_mtxpool, pm); + + md->pmd_write_pmc(cpu, ri, newvalue); + md->pmd_start_pmc(cpu, ri); + + } + + /* + * perform any other architecture/cpu dependent thread + * switch-in actions. + */ + + (void) (*md->pmd_switch_in)(pc); + + critical_exit(); + + } + break; + + /* + * Thread context switch OUT. + */ + + case PMC_FN_CSW_OUT: + { + int cpu; + unsigned int ri; + struct pmc *pm; + struct proc *p; + struct pmc_cpu *pc; + struct pmc_hw *phw; + struct pmc_process *pp; + pmc_value_t newvalue, tmp; + + /* + * Locate our process descriptor; this may be NULL if + * this process is exiting and we have already removed + * the process from the target process table. + * + * Note that due to kernel preemption, multiple + * context switches may happen while the process is + * exiting. + * + * Note also that if the target process cannot be + * found we still need to deconfigure any PMCs that + * are currently running on hardware. + */ + + p = td->td_proc; + pp = pmc_find_process_descriptor(p, PMC_FLAG_NONE); + + /* + * save PMCs + */ + + critical_enter(); + + cpu = PCPU_GET(cpuid); /* td->td_oncpu is invalid */ + + PMCDBG(CTX,SWO,1, "cpu=%d proc=%p (%d, %s) pp=%p", cpu, p, + p->p_pid, p->p_comm, pp); + + KASSERT(cpu >= 0 && cpu < mp_ncpus, + ("[pmc,%d wierd CPU id %d", __LINE__, cpu)); + + pc = pmc_pcpu[cpu]; + + /* + * When a PMC gets unlinked from a target PMC, it will + * be removed from the target's pp_pmc[] array. + * + * However, on a MP system, the target could have been + * executing on another CPU at the time of the unlink. + * So, at context switch OUT time, we need to look at + * the hardware to determine if a PMC is scheduled on + * it. + */ + + for (ri = 0; ri < md->pmd_npmc; ri++) { + + phw = pc->pc_hwpmcs[ri]; + pm = phw->phw_pmc; + + if (pm == NULL) /* nothing at this row index */ + continue; + + if (!PMC_IS_VIRTUAL_MODE(pm->pm_mode)) + continue; /* not a process virtual PMC */ + + KASSERT(pm->pm_rowindex == ri, + ("[pmc,%d] ri mismatch pmc(%d) ri(%d)", + __LINE__, pm->pm_rowindex, ri)); + + /* Stop hardware */ + md->pmd_stop_pmc(cpu, ri); + + /* reduce this PMC's runcount */ + atomic_subtract_rel_32(&pm->pm_runcount, 1); + + /* + * If this PMC is associated with this process, + * save the reading. + */ + + if (pp != NULL && pp->pp_pmcs[ri].pp_pmc != NULL) { + + KASSERT(pm == pp->pp_pmcs[ri].pp_pmc, + ("[pmc,%d] pm %p != pp_pmcs[%d] %p", + __LINE__, pm, ri, + pp->pp_pmcs[ri].pp_pmc)); + + KASSERT(pp->pp_refcnt > 0, + ("[pmc,%d] pp refcnt = %d", __LINE__, + pp->pp_refcnt)); + + md->pmd_read_pmc(cpu, ri, &newvalue); + + tmp = newvalue - PMC_PCPU_SAVED(cpu,ri); + + KASSERT((int64_t) tmp >= 0, + ("[pmc,%d] negative increment cpu=%d " + "ri=%d newvalue=%jx saved=%jx " + "incr=%jx", __LINE__, cpu, ri, + newvalue, PMC_PCPU_SAVED(cpu,ri), + tmp)); + + /* + * Increment the PMC's count and this + * target process's count by the difference + * between the current reading and the + * saved value at context switch in time. + */ + + mtx_pool_lock_spin(pmc_mtxpool, pm); + + pm->pm_gv.pm_savedvalue += tmp; + pp->pp_pmcs[ri].pp_pmcval += tmp; + + mtx_pool_unlock_spin(pmc_mtxpool, pm); + + } + + /* mark hardware as free */ + md->pmd_config_pmc(cpu, ri, NULL); + } + + /* + * perform any other architecture/cpu dependent thread + * switch out functions. + */ + + (void) (*md->pmd_switch_out)(pc); + + critical_exit(); + + } + break; + + default: +#if DEBUG + KASSERT(0, ("[pmc,%d] unknown hook %d\n", __LINE__, function)); +#endif + break; + + } + + return 0; +} + +/* + * allocate a 'struct pmc_owner' descriptor in the owner hash table. + */ + +static struct pmc_owner * +pmc_allocate_owner_descriptor(struct proc *p) +{ + uint32_t hindex; + struct pmc_owner *po; + struct pmc_ownerhash *poh; + + hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); + poh = &pmc_ownerhash[hindex]; + + /* allocate space for N pointers and one descriptor struct */ + MALLOC(po, struct pmc_owner *, sizeof(struct pmc_owner), + M_PMC, M_WAITOK); + + po->po_flags = 0; + po->po_owner = p; + LIST_INIT(&po->po_pmcs); + LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */ + + PMCDBG(OWN,ALL,1, "allocate-owner proc=%p (%d, %s) pmc-owner=%p", + p, p->p_pid, p->p_comm, po); + + return po; +} + +/* + * find the descriptor corresponding to process 'p', adding or removing it + * as specified by 'mode'. + */ + +static struct pmc_process * +pmc_find_process_descriptor(struct proc *p, uint32_t mode) +{ + uint32_t hindex; + struct pmc_process *pp, *ppnew; + struct pmc_processhash *pph; + + hindex = PMC_HASH_PTR(p, pmc_processhashmask); + pph = &pmc_processhash[hindex]; + + ppnew = NULL; + + /* + * Pre-allocate memory in the FIND_ALLOCATE case since we + * cannot call malloc(9) once we hold a spin lock. + */ + + if (mode & PMC_FLAG_ALLOCATE) { + /* allocate additional space for 'n' pmc pointers */ + MALLOC(ppnew, struct pmc_process *, + sizeof(struct pmc_process) + md->pmd_npmc * + sizeof(struct pmc_targetstate), M_PMC, M_ZERO|M_WAITOK); + } + + mtx_lock_spin(&pmc_processhash_mtx); + LIST_FOREACH(pp, pph, pp_next) + if (pp->pp_proc == p) + break; + + if ((mode & PMC_FLAG_REMOVE) && pp != NULL) + LIST_REMOVE(pp, pp_next); + + if ((mode & PMC_FLAG_ALLOCATE) && pp == NULL && + ppnew != NULL) { + ppnew->pp_proc = p; + LIST_INSERT_HEAD(pph, ppnew, pp_next); + pp = ppnew; + ppnew = NULL; + } + mtx_unlock_spin(&pmc_processhash_mtx); + + if (pp != NULL && ppnew != NULL) + FREE(ppnew, M_PMC); + + return pp; +} + +/* + * remove a process descriptor from the process hash table. + */ + +static void +pmc_remove_process_descriptor(struct pmc_process *pp) +{ + KASSERT(pp->pp_refcnt == 0, + ("[pmc,%d] Removing process descriptor %p with count %d", + __LINE__, pp, pp->pp_refcnt)); + + mtx_lock_spin(&pmc_processhash_mtx); + LIST_REMOVE(pp, pp_next); + mtx_unlock_spin(&pmc_processhash_mtx); +} + + +/* + * find an owner descriptor corresponding to proc 'p' + */ + +static struct pmc_owner * +pmc_find_owner_descriptor(struct proc *p) +{ + uint32_t hindex; + struct pmc_owner *po; + struct pmc_ownerhash *poh; + + hindex = PMC_HASH_PTR(p, pmc_ownerhashmask); + poh = &pmc_ownerhash[hindex]; + + po = NULL; + LIST_FOREACH(po, poh, po_next) + if (po->po_owner == p) + break; + + PMCDBG(OWN,FND,1, "find-owner proc=%p (%d, %s) hindex=0x%x -> " + "pmc-owner=%p", p, p->p_pid, p->p_comm, hindex, po); + + return po; +} + +/* + * pmc_allocate_pmc_descriptor + * + * Allocate a pmc descriptor and initialize its + * fields. + */ + +static struct pmc * +pmc_allocate_pmc_descriptor(void) +{ + struct pmc *pmc; + + MALLOC(pmc, struct pmc *, sizeof(struct pmc), M_PMC, M_ZERO|M_WAITOK); + + if (pmc != NULL) { + pmc->pm_owner = NULL; + LIST_INIT(&pmc->pm_targets); + } + + PMCDBG(PMC,ALL,1, "allocate-pmc -> pmc=%p", pmc); + + return pmc; +} + +/* + * Destroy a pmc descriptor. + */ + +static void +pmc_destroy_pmc_descriptor(struct pmc *pm) +{ + (void) pm; + +#if DEBUG + KASSERT(pm->pm_state == PMC_STATE_DELETED || + pm->pm_state == PMC_STATE_FREE, + ("[pmc,%d] destroying non-deleted PMC", __LINE__)); + KASSERT(LIST_EMPTY(&pm->pm_targets), + ("[pmc,%d] destroying pmc with targets", __LINE__)); + KASSERT(pm->pm_owner == NULL, + ("[pmc,%d] destroying pmc attached to an owner", __LINE__)); + KASSERT(pm->pm_runcount == 0, + ("[pmc,%d] pmc has non-zero run count %d", __LINE__, + pm->pm_runcount)); +#endif +} + +/* + * This function does the following things: + * + * - detaches the PMC from hardware + * - unlinks all target threads that were attached to it + * - removes the PMC from its owner's list + * - destroy's the PMC private mutex + * + * Once this function completes, the given pmc pointer can be safely + * FREE'd by the caller. + */ + +static void +pmc_release_pmc_descriptor(struct pmc *pm) +{ +#if DEBUG + volatile int maxloop; +#endif + u_int ri, cpu; + u_char curpri; + struct pmc_hw *phw; + struct pmc_process *pp; + struct pmc_target *ptgt, *tmp; + struct pmc_binding pb; + + sx_assert(&pmc_sx, SX_XLOCKED); + + KASSERT(pm, ("[pmc,%d] null pmc", __LINE__)); + + ri = pm->pm_rowindex; + + PMCDBG(PMC,REL,1, "release-pmc pmc=%p ri=%d mode=%d", pm, ri, + pm->pm_mode); + + /* + * First, we take the PMC off hardware. + */ + + if (PMC_IS_SYSTEM_MODE(pm->pm_mode)) { + + /* + * A system mode PMC runs on a specific CPU. Switch + * to this CPU and turn hardware off. + */ + + pmc_save_cpu_binding(&pb); + + cpu = pm->pm_gv.pm_cpu; + + if (pm->pm_state == PMC_STATE_RUNNING) { + + pmc_select_cpu(cpu); + + phw = pmc_pcpu[cpu]->pc_hwpmcs[ri]; + + KASSERT(phw->phw_pmc == pm, + ("[pmc, %d] pmc ptr ri(%d) hw(%p) pm(%p)", + __LINE__, ri, phw->phw_pmc, pm)); + + PMCDBG(PMC,REL,2, "stopping cpu=%d ri=%d", cpu, ri); + + critical_enter(); + md->pmd_stop_pmc(cpu, ri); + critical_exit(); + } + + PMCDBG(PMC,REL,2, "decfg cpu=%d ri=%d", cpu, ri); + + critical_enter(); + md->pmd_config_pmc(cpu, ri, NULL); + critical_exit(); + + pm->pm_state = PMC_STATE_DELETED; + + pmc_restore_cpu_binding(&pb); + + } else if (PMC_IS_VIRTUAL_MODE(pm->pm_mode)) { + + /* + * A virtual PMC could be running on multiple CPUs at + * a given instant. + * + * By marking its state as DELETED, we ensure that + * this PMC is never further scheduled on hardware. + * + * Then we wait till all CPUs are done with this PMC. + */ + + pm->pm_state = PMC_STATE_DELETED; + + + /* + * Wait for the PMCs runcount to come to zero. + */ + +#if DEBUG + maxloop = 100 * mp_ncpus; +#endif + + while (atomic_load_acq_32(&pm->pm_runcount) > 0) { + +#if DEBUG + maxloop--; + KASSERT(maxloop > 0, + ("[pmc,%d] (ri%d, rc%d) waiting too long for " + "pmc to be free", __LINE__, pm->pm_rowindex, + pm->pm_runcount)); +#endif + + mtx_lock_spin(&sched_lock); + curpri = curthread->td_priority; + mtx_unlock_spin(&sched_lock); + + (void) tsleep((void *) pmc_release_pmc_descriptor, + curpri, "pmcrel", 1); + + } + + /* + * At this point the PMC is off all CPUs and cannot be + * freshly scheduled onto a CPU. It is now safe to + * unlink all targets from this PMC. If a + * process-record's refcount falls to zero, we remove + * it from the hash table. The module-wide SX lock + * protects us from races. + */ + + LIST_FOREACH_SAFE(ptgt, &pm->pm_targets, pt_next, tmp) { + pp = ptgt->pt_process; + pmc_unlink_target_process(pm, pp); /* frees 'ptgt' */ + + PMCDBG(PMC,REL,3, "pp->refcnt=%d", pp->pp_refcnt); + + /* + * If the target process record shows that no + * PMCs are attached to it, reclaim its space. + */ + + if (pp->pp_refcnt == 0) { + pmc_remove_process_descriptor(pp); + FREE(pp, M_PMC); + } + } + + cpu = curthread->td_oncpu; /* setup cpu for pmd_release() */ + + } + + /* + * Release any MD resources + */ + + (void) md->pmd_release_pmc(cpu, ri, pm); + + /* + * Update row disposition + */ + + if (PMC_IS_SYSTEM_MODE(pm->pm_mode)) + PMC_UNMARK_ROW_STANDALONE(ri); + else + PMC_UNMARK_ROW_THREAD(ri); + + /* unlink from the owner's list */ + if (pm->pm_owner) + pmc_unlink_owner(pm); + + pmc_destroy_pmc_descriptor(pm); +} + +/* + * Register an owner and a pmc. + */ + +static int +pmc_register_owner(struct proc *p, struct pmc *pmc) +{ + struct pmc_list *pl; + struct pmc_owner *po; + + sx_assert(&pmc_sx, SX_XLOCKED); + + MALLOC(pl, struct pmc_list *, sizeof(struct pmc_list), M_PMC, + M_WAITOK); + + if (pl == NULL) + return ENOMEM; + + if ((po = pmc_find_owner_descriptor(p)) == NULL) { + if ((po = pmc_allocate_owner_descriptor(p)) == NULL) { + FREE(pl, M_PMC); + return ENOMEM; + } + po->po_flags |= PMC_FLAG_IS_OWNER; /* real owner */ + } + + if (pmc->pm_mode == PMC_MODE_TS) { + /* can have only one TS mode PMC per process */ + if (po->po_flags & PMC_FLAG_HAS_TS_PMC) { + FREE(pl, M_PMC); + return EINVAL; + } + po->po_flags |= PMC_FLAG_HAS_TS_PMC; + } + + KASSERT(pmc->pm_owner == NULL, + ("[pmc,%d] attempting to own an initialized PMC", __LINE__)); + pmc->pm_owner = po; + + pl->pl_pmc = pmc; + + LIST_INSERT_HEAD(&po->po_pmcs, pl, pl_next); + + PROC_LOCK(p); + p->p_flag |= P_HWPMC; + PROC_UNLOCK(p); + + PMCDBG(PMC,REG,1, "register-owner pmc-owner=%p pl=%p pmc=%p", + po, pl, pmc); + + return 0; +} + +/* + * Return the current row disposition: + * == 0 => FREE + * > 0 => PROCESS MODE + * < 0 => SYSTEM MODE + */ + +int +pmc_getrowdisp(int ri) +{ + return pmc_pmcdisp[ri]; +} + +/* + * Check if a PMC at row index 'ri' can be allocated to the current + * process. + * + * Allocation can fail if: + * - the current process is already being profiled by a PMC at index 'ri', + * attached to it via OP_PMCATTACH. + * - the current process has already allocated a PMC at index 'ri' + * via OP_ALLOCATE. + */ + +static int +pmc_can_allocate_rowindex(struct proc *p, unsigned int ri) +{ + struct pmc_list *pl; + struct pmc_owner *po; + struct pmc_process *pp; + + PMCDBG(PMC,ALR,1, "can-allocate-rowindex proc=%p (%d, %s) ri=%d", + p, p->p_pid, p->p_comm, ri); + + /* we shouldn't have allocated a PMC at row index 'ri' */ + if ((po = pmc_find_owner_descriptor(p)) != NULL) + LIST_FOREACH(pl, &po->po_pmcs, pl_next) + if (pl->pl_pmc->pm_rowindex == ri) + return EEXIST; + + /* we shouldn't be the target of any PMC ourselves at this index */ + if ((pp = pmc_find_process_descriptor(p, 0)) != NULL) + if (pp->pp_pmcs[ri].pp_pmc) + return EEXIST; + + PMCDBG(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok", + p, p->p_pid, p->p_comm, ri); + + return 0; +} + +/* + * Check if a given PMC at row index 'ri' can be currently used in + * mode 'mode'. + */ + +static int +pmc_can_allocate_row(int ri, enum pmc_mode mode) +{ + enum pmc_disp disp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + PMCDBG(PMC,ALR,1, "can-allocate-row ri=%d mode=%d", ri, mode); + + if (PMC_IS_SYSTEM_MODE(mode)) + disp = PMC_DISP_STANDALONE; + else + disp = PMC_DISP_THREAD; + + /* + * check disposition for PMC row 'ri': + * + * Expected disposition Row-disposition Result + * + * STANDALONE STANDALONE or FREE proceed + * STANDALONE THREAD fail + * THREAD THREAD or FREE proceed + * THREAD STANDALONE fail + */ + + if (!PMC_ROW_DISP_IS_FREE(ri) && + !(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) && + !(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri))) + return EBUSY; + + /* + * All OK + */ + + PMCDBG(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode); + + return 0; + +} + +/* + * Find a PMC descriptor with user handle 'pmc' for thread 'td'. + */ + +static struct pmc * +pmc_find_pmc_descriptor_in_process(struct pmc_owner *po, pmc_id_t pmcid) +{ + struct pmc_list *pl; + + KASSERT(pmcid < md->pmd_npmc, + ("[pmc,%d] Illegal pmc index %d (max %d)", __LINE__, pmcid, + md->pmd_npmc)); + + LIST_FOREACH(pl, &po->po_pmcs, pl_next) + if (pl->pl_pmc->pm_rowindex == pmcid) + return pl->pl_pmc; + + return NULL; +} + +static int +pmc_find_pmc(pmc_id_t pmcid, struct pmc **pmc) +{ + + struct pmc *pm; + struct pmc_owner *po; + + PMCDBG(PMC,FND,1, "find-pmc id=%d", pmcid); + + if ((po = pmc_find_owner_descriptor(curthread->td_proc)) == NULL) + return ESRCH; + + if ((pm = pmc_find_pmc_descriptor_in_process(po, pmcid)) == NULL) + return EINVAL; + + PMCDBG(PMC,FND,2, "find-pmc id=%d -> pmc=%p", pmcid, pm); + + *pmc = pm; + return 0; +} + +/* + * Start a PMC. + */ + +static int +pmc_start(struct pmc *pm) +{ + int error, cpu, ri; + struct pmc_binding pb; + + KASSERT(pm != NULL, + ("[pmc,%d] null pm", __LINE__)); + + PMCDBG(PMC,OPS,1, "start pmc=%p mode=%d ri=%d", pm, pm->pm_mode, + pm->pm_rowindex); + + pm->pm_state = PMC_STATE_RUNNING; + + if (PMC_IS_VIRTUAL_MODE(pm->pm_mode)) { + + /* + * If a PMCATTACH hadn't been done on this + * PMC, attach this PMC to its owner process. + */ + + if (LIST_EMPTY(&pm->pm_targets)) + return pmc_attach_process(pm->pm_owner->po_owner, pm); + + + /* + * Nothing further to be done; thread context switch code + * will start/stop the PMC as appropriate. + */ + + return 0; + + } + + /* + * A system-mode PMC. Move to the CPU associated with this + * PMC, and start the hardware. + */ + + pmc_save_cpu_binding(&pb); + + cpu = pm->pm_gv.pm_cpu; + + if (pmc_cpu_is_disabled(cpu)) + return ENXIO; + + ri = pm->pm_rowindex; + + pmc_select_cpu(cpu); + + /* + * global PMCs are configured at allocation time + * so write out the initial value and start the PMC. + */ + + if ((error = md->pmd_write_pmc(cpu, ri, + PMC_IS_SAMPLING_MODE(pm->pm_mode) ? + pm->pm_sc.pm_reloadcount : + pm->pm_sc.pm_initial)) == 0) + error = md->pmd_start_pmc(cpu, ri); + + pmc_restore_cpu_binding(&pb); + + return error; +} + +/* + * Stop a PMC. + */ + +static int +pmc_stop(struct pmc *pm) +{ + int error, cpu; + struct pmc_binding pb; + + KASSERT(pm != NULL, ("[pmc,%d] null pmc", __LINE__)); + + PMCDBG(PMC,OPS,1, "stop pmc=%p mode=%d ri=%d", pm, pm->pm_mode, + pm->pm_rowindex); + + pm->pm_state = PMC_STATE_STOPPED; + + /* + * If the PMC is a virtual mode one, changing the state to + * non-RUNNING is enough to ensure that the PMC never gets + * scheduled. + * + * If this PMC is current running on a CPU, then it will + * handled correctly at the time its target process is context + * switched out. + */ + + if (PMC_IS_VIRTUAL_MODE(pm->pm_mode)) + return 0; + + /* + * A system-mode PMC. Move to the CPU associated with + * this PMC, and stop the hardware. We update the + * 'initial count' so that a subsequent PMCSTART will + * resume counting from the current hardware count. + */ + + pmc_save_cpu_binding(&pb); + + cpu = pm->pm_gv.pm_cpu; + + if (pmc_cpu_is_disabled(cpu)) + return ENXIO; + + pmc_select_cpu(cpu); + + if ((error = md->pmd_stop_pmc(cpu, pm->pm_rowindex)) == 0) + error = md->pmd_read_pmc(cpu, pm->pm_rowindex, + &pm->pm_sc.pm_initial); + + pmc_restore_cpu_binding(&pb); + + return error; +} + + +#if DEBUG +static const char *pmc_op_to_name[] = { +#undef __PMC_OP +#define __PMC_OP(N, D) #N , + __PMC_OPS() + NULL +}; +#endif + +/* + * The syscall interface + */ + +#define PMC_GET_SX_XLOCK(...) do { \ + sx_xlock(&pmc_sx); \ + if (pmc_hook == NULL) { \ + sx_xunlock(&pmc_sx); \ + return __VA_ARGS__; \ + } \ +} while (0) + +#define PMC_DOWNGRADE_SX() do { \ + sx_downgrade(&pmc_sx); \ + is_sx_downgraded = 1; \ +} while (0) + +static int +pmc_syscall_handler(struct thread *td, void *syscall_args) +{ + int error, is_sx_downgraded, op; + struct pmc_syscall_args *c; + void *arg; + + PMC_GET_SX_XLOCK(ENOSYS); + + is_sx_downgraded = 0; + + c = (struct pmc_syscall_args *) syscall_args; + + op = c->pmop_code; + arg = c->pmop_data; + + PMCDBG(MOD,PMS,1, "syscall op=%d \"%s\" arg=%p", op, + pmc_op_to_name[op], arg); + + error = 0; + atomic_add_int(&pmc_stats.pm_syscalls, 1); + + switch(op) + { + + + /* + * Configure a log file. + * + * XXX This OP will be reworked. + */ + + case PMC_OP_CONFIGURELOG: + { + struct pmc_owner *po; + struct pmc_op_configurelog cl; + struct proc *p; + + sx_assert(&pmc_sx, SX_XLOCKED); + + if ((error = copyin(arg, &cl, sizeof(cl))) != 0) + break; + + /* mark this process as owning a log file */ + p = td->td_proc; + if ((po = pmc_find_owner_descriptor(p)) == NULL) + if ((po = pmc_allocate_owner_descriptor(p)) == NULL) + return ENOMEM; + + if ((error = pmc_configure_log(po, cl.pm_logfd)) != 0) + break; + + } + break; + + + /* + * Retrieve hardware configuration. + */ + + case PMC_OP_GETCPUINFO: /* CPU information */ + { + struct pmc_op_getcpuinfo gci; + + gci.pm_cputype = md->pmd_cputype; + gci.pm_npmc = md->pmd_npmc; + gci.pm_nclass = md->pmd_nclass; + bcopy(md->pmd_classes, &gci.pm_classes, + sizeof(gci.pm_classes)); + gci.pm_ncpu = mp_ncpus; + error = copyout(&gci, arg, sizeof(gci)); + } + break; + + + /* + * Get module statistics + */ + + case PMC_OP_GETDRIVERSTATS: + { + struct pmc_op_getdriverstats gms; + + bcopy(&pmc_stats, &gms, sizeof(gms)); + error = copyout(&gms, arg, sizeof(gms)); + } + break; + + + /* + * Retrieve module version number + */ + + case PMC_OP_GETMODULEVERSION: + { + error = copyout(&_pmc_version.mv_version, arg, sizeof(int)); + } + break; + + + /* + * Retrieve the state of all the PMCs on a given + * CPU. + */ + + case PMC_OP_GETPMCINFO: + { + uint32_t cpu, n, npmc; + size_t pmcinfo_size; + struct pmc *pm; + struct pmc_info *p, *pmcinfo; + struct pmc_op_getpmcinfo *gpi; + struct pmc_owner *po; + struct pmc_binding pb; + + PMC_DOWNGRADE_SX(); + + gpi = (struct pmc_op_getpmcinfo *) arg; + + if ((error = copyin(&gpi->pm_cpu, &cpu, sizeof(cpu))) != 0) + break; + + if (cpu >= (unsigned int) mp_ncpus) { + error = EINVAL; + break; + } + + if (pmc_cpu_is_disabled(cpu)) { + error = ENXIO; + break; + } + + /* switch to CPU 'cpu' */ + pmc_save_cpu_binding(&pb); + pmc_select_cpu(cpu); + + npmc = md->pmd_npmc; + + pmcinfo_size = npmc * sizeof(struct pmc_info); + MALLOC(pmcinfo, struct pmc_info *, pmcinfo_size, M_PMC, + M_WAITOK); + + p = pmcinfo; + + for (n = 0; n < md->pmd_npmc; n++, p++) { + + if ((error = md->pmd_describe(cpu, n, p, &pm)) != 0) + break; + + if (PMC_ROW_DISP_IS_STANDALONE(n)) + p->pm_rowdisp = PMC_DISP_STANDALONE; + else if (PMC_ROW_DISP_IS_THREAD(n)) + p->pm_rowdisp = PMC_DISP_THREAD; + else + p->pm_rowdisp = PMC_DISP_FREE; + + p->pm_ownerpid = -1; + + if (pm == NULL) /* no PMC associated */ + continue; + + po = pm->pm_owner; + + KASSERT(po->po_owner != NULL, + ("[pmc,%d] pmc_owner had a null proc pointer", + __LINE__)); + + p->pm_ownerpid = po->po_owner->p_pid; + p->pm_mode = pm->pm_mode; + p->pm_event = pm->pm_event; + p->pm_flags = pm->pm_flags; + + if (PMC_IS_SAMPLING_MODE(pm->pm_mode)) + p->pm_reloadcount = + pm->pm_sc.pm_reloadcount; + } + + pmc_restore_cpu_binding(&pb); + + /* now copy out the PMC info collected */ + if (error == 0) + error = copyout(pmcinfo, &gpi->pm_pmcs, pmcinfo_size); + + FREE(pmcinfo, M_PMC); + } + break; + + + /* + * Set the administrative state of a PMC. I.e. whether + * the PMC is to be used or not. + */ + + case PMC_OP_PMCADMIN: + { + int cpu, ri; + enum pmc_state request; + struct pmc_cpu *pc; + struct pmc_hw *phw; + struct pmc_op_pmcadmin pma; + struct pmc_binding pb; + + sx_assert(&pmc_sx, SX_XLOCKED); + + KASSERT(td == curthread, + ("[pmc,%d] td != curthread", __LINE__)); + + if (suser(td) || jailed(td->td_ucred)) { + error = EPERM; + break; + } + + if ((error = copyin(arg, &pma, sizeof(pma))) != 0) + break; + + cpu = pma.pm_cpu; + + if (cpu < 0 || cpu >= mp_ncpus) { + error = EINVAL; + break; + } + + if (pmc_cpu_is_disabled(cpu)) { + error = ENXIO; + break; + } + + request = pma.pm_state; + + if (request != PMC_STATE_DISABLED && + request != PMC_STATE_FREE) { + error = EINVAL; + break; + } + + ri = pma.pm_pmc; /* pmc id == row index */ + if (ri < 0 || ri >= (int) md->pmd_npmc) { + error = EINVAL; + break; + } + + /* + * We can't disable a PMC with a row-index allocated + * for process virtual PMCs. + */ + + if (PMC_ROW_DISP_IS_THREAD(ri) && + request == PMC_STATE_DISABLED) { + error = EBUSY; + break; + } + + /* + * otherwise, this PMC on this CPU is either free or + * in system-wide mode. + */ + + pmc_save_cpu_binding(&pb); + pmc_select_cpu(cpu); + + pc = pmc_pcpu[cpu]; + phw = pc->pc_hwpmcs[ri]; + + /* + * XXX do we need some kind of 'forced' disable? + */ + + if (phw->phw_pmc == NULL) { + if (request == PMC_STATE_DISABLED && + (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED)) { + phw->phw_state &= ~PMC_PHW_FLAG_IS_ENABLED; + PMC_MARK_ROW_STANDALONE(ri); + } else if (request == PMC_STATE_FREE && + (phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0) { + phw->phw_state |= PMC_PHW_FLAG_IS_ENABLED; + PMC_UNMARK_ROW_STANDALONE(ri); + } + /* other cases are a no-op */ + } else + error = EBUSY; + + pmc_restore_cpu_binding(&pb); + } + break; + + + /* + * Allocate a PMC. + */ + + case PMC_OP_PMCALLOCATE: + { + uint32_t caps; + u_int cpu; + int n; + enum pmc_mode mode; + struct pmc *pmc; + struct pmc_op_pmcallocate pa; + struct pmc_binding pb; + + if ((error = copyin(arg, &pa, sizeof(pa))) != 0) + break; + + caps = pa.pm_caps; + mode = pa.pm_mode; + cpu = pa.pm_cpu; + + if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC && + mode != PMC_MODE_TS && mode != PMC_MODE_TC) || + (cpu != (u_int) PMC_CPU_ANY && cpu >= (u_int) mp_ncpus)) { + error = EINVAL; + break; + } + + /* + * Virtual PMCs should only ask for a default CPU. + * System mode PMCs need to specify a non-default CPU. + */ + + if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) || + (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) { + error = EINVAL; + break; + } + + /* + * Check that a disabled CPU is not being asked for. + */ + + if (PMC_IS_SYSTEM_MODE(mode) && pmc_cpu_is_disabled(cpu)) { + error = ENXIO; + break; + } + + /* + * Refuse an allocation for a system-wide PMC if this + * process has been jailed, or if this process lacks + * super-user credentials and the sysctl tunable + * 'security.bsd.unprivileged_syspmcs' is zero. + */ + + if (PMC_IS_SYSTEM_MODE(mode)) { + if (jailed(curthread->td_ucred)) + error = EPERM; + else if (suser(curthread) && + (pmc_unprivileged_syspmcs == 0)) + error = EPERM; + } + + if (error) + break; + + /* + * Look for valid values for 'pm_flags' + */ + + if ((pa.pm_flags & ~(PMC_F_DESCENDANTS|PMC_F_LOG_TC_CSW)) + != 0) { + error = EINVAL; + break; + } + + /* + * All sampling mode PMCs need to be able to interrupt the + * CPU. + */ + + if (PMC_IS_SAMPLING_MODE(mode)) { + caps |= PMC_CAP_INTERRUPT; + error = ENOSYS; /* for snapshot 6 */ + break; + } + + PMCDBG(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", + pa.pm_ev, caps, mode, cpu); + + pmc = pmc_allocate_pmc_descriptor(); + pmc->pm_event = pa.pm_ev; + pmc->pm_class = pa.pm_class; + pmc->pm_state = PMC_STATE_FREE; + pmc->pm_mode = mode; + pmc->pm_caps = caps; + pmc->pm_flags = pa.pm_flags; + + /* switch thread to CPU 'cpu' */ + pmc_save_cpu_binding(&pb); + +#define PMC_IS_SHAREABLE_PMC(cpu, n) \ + (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \ + PMC_PHW_FLAG_IS_SHAREABLE) +#define PMC_IS_UNALLOCATED(cpu, n) \ + (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL) + + if (PMC_IS_SYSTEM_MODE(mode)) { + pmc_select_cpu(cpu); + for (n = 0; n < (int) md->pmd_npmc; n++) + if (pmc_can_allocate_row(n, mode) == 0 && + pmc_can_allocate_rowindex( + curthread->td_proc, n) == 0 && + (PMC_IS_UNALLOCATED(cpu, n) || + PMC_IS_SHAREABLE_PMC(cpu, n)) && + md->pmd_allocate_pmc(cpu, n, pmc, + &pa) == 0) + break; + } else { + /* Process virtual mode */ + for (n = 0; n < (int) md->pmd_npmc; n++) { + if (pmc_can_allocate_row(n, mode) == 0 && + pmc_can_allocate_rowindex( + curthread->td_proc, n) == 0 && + md->pmd_allocate_pmc(curthread->td_oncpu, + n, pmc, &pa) == 0) + break; + } + } + +#undef PMC_IS_UNALLOCATED +#undef PMC_IS_SHAREABLE_PMC + + pmc_restore_cpu_binding(&pb); + + if (n == (int) md->pmd_npmc) { + pmc_destroy_pmc_descriptor(pmc); + FREE(pmc, M_PMC); + pmc = NULL; + error = EINVAL; + break; + } + + PMCDBG(PMC,ALL,2, "ev=%d class=%d mode=%d -> n=%d", + pmc->pm_event, pmc->pm_class, pmc->pm_mode, n); + + /* + * Configure global pmc's immediately + */ + + if (PMC_IS_SYSTEM_MODE(pmc->pm_mode)) + if ((error = md->pmd_config_pmc(cpu, n, pmc)) != 0) { + (void) md->pmd_release_pmc(cpu, n, pmc); + pmc_destroy_pmc_descriptor(pmc); + FREE(pmc, M_PMC); + pmc = NULL; + break; + } + + /* + * Mark the row index allocated. + */ + + pmc->pm_rowindex = n; + pmc->pm_state = PMC_STATE_ALLOCATED; + + /* + * mark row disposition + */ + + if (PMC_IS_SYSTEM_MODE(mode)) + PMC_MARK_ROW_STANDALONE(n); + else + PMC_MARK_ROW_THREAD(n); + + /* + * If this is a system-wide CPU, mark the CPU it + * was allocated on. + */ + + if (PMC_IS_SYSTEM_MODE(mode)) + pmc->pm_gv.pm_cpu = cpu; + + /* + * Register this PMC with the current thread as its owner. + */ + + if ((error = + pmc_register_owner(curthread->td_proc, pmc)) != 0) { + pmc_release_pmc_descriptor(pmc); + FREE(pmc, M_PMC); + pmc = NULL; + break; + } + + /* + * Return the allocated index. + */ + + pa.pm_pmcid = n; + + error = copyout(&pa, arg, sizeof(pa)); + } + break; + + + /* + * Attach a PMC to a process. + */ + + case PMC_OP_PMCATTACH: + { + struct pmc *pm; + struct proc *p; + struct pmc_op_pmcattach a; + + sx_assert(&pmc_sx, SX_XLOCKED); + + if ((error = copyin(arg, &a, sizeof(a))) != 0) + break; + + if (a.pm_pid < 0) { + error = EINVAL; + break; + } else if (a.pm_pid == 0) + a.pm_pid = td->td_proc->p_pid; + + if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) + break; + + if (PMC_IS_SYSTEM_MODE(pm->pm_mode)) { + error = EINVAL; + break; + } + + /* PMCs may be (re)attached only when allocated or stopped */ + if (pm->pm_state == PMC_STATE_RUNNING) { + error = EBUSY; + break; + } else if (pm->pm_state != PMC_STATE_ALLOCATED && + pm->pm_state != PMC_STATE_STOPPED) { + error = EINVAL; + break; + } + + /* lookup pid */ + if ((p = pfind(a.pm_pid)) == NULL) { + error = ESRCH; + break; + } + + /* + * Ignore processes that are working on exiting. + */ + if (p->p_flag & P_WEXIT) { + error = ESRCH; + PROC_UNLOCK(p); /* pfind() returns a locked process */ + break; + } + + /* + * we are allowed to attach a PMC to a process if + * we can debug it. + */ + error = p_candebug(curthread, p); + + PROC_UNLOCK(p); + + if (error == 0) + error = pmc_attach_process(p, pm); + } + break; + + + /* + * Detach an attached PMC from a process. + */ + + case PMC_OP_PMCDETACH: + { + struct pmc *pm; + struct proc *p; + struct pmc_op_pmcattach a; + + if ((error = copyin(arg, &a, sizeof(a))) != 0) + break; + + if (a.pm_pid < 0) { + error = EINVAL; + break; + } else if (a.pm_pid == 0) + a.pm_pid = td->td_proc->p_pid; + + if ((error = pmc_find_pmc(a.pm_pmc, &pm)) != 0) + break; + + if ((p = pfind(a.pm_pid)) == NULL) { + error = ESRCH; + break; + } + + /* + * Treat processes that are in the process of exiting + * as if they were not present. + */ + + if (p->p_flag & P_WEXIT) + error = ESRCH; + + PROC_UNLOCK(p); /* pfind() returns a locked process */ + + if (error == 0) + error = pmc_detach_process(p, pm); + } + break; + + + /* + * Release an allocated PMC + */ + + case PMC_OP_PMCRELEASE: + { + pmc_id_t pmcid; + struct pmc *pm; + struct pmc_owner *po; + struct pmc_op_simple sp; + + /* + * Find PMC pointer for the named PMC. + * + * Use pmc_release_pmc_descriptor() to switch off the + * PMC, remove all its target threads, and remove the + * PMC from its owner's list. + * + * Remove the owner record if this is the last PMC + * owned. + * + * Free up space. + */ + + if ((error = copyin(arg, &sp, sizeof(sp))) != 0) + break; + + pmcid = sp.pm_pmcid; + + if ((error = pmc_find_pmc(pmcid, &pm)) != 0) + break; + + po = pm->pm_owner; + pmc_release_pmc_descriptor(pm); + pmc_maybe_remove_owner(po); + + FREE(pm, M_PMC); + } + break; + + + /* + * Read and/or write a PMC. + */ + + case PMC_OP_PMCRW: + { + uint32_t cpu, ri; + struct pmc *pm; + struct pmc_op_pmcrw *pprw; + struct pmc_op_pmcrw prw; + struct pmc_binding pb; + pmc_value_t oldvalue; + + PMC_DOWNGRADE_SX(); + + if ((error = copyin(arg, &prw, sizeof(prw))) != 0) + break; + + PMCDBG(PMC,OPS,1, "rw id=%d flags=0x%x", prw.pm_pmcid, + prw.pm_flags); + + /* must have at least one flag set */ + if ((prw.pm_flags & (PMC_F_OLDVALUE|PMC_F_NEWVALUE)) == 0) { + error = EINVAL; + break; + } + + /* locate pmc descriptor */ + if ((error = pmc_find_pmc(prw.pm_pmcid, &pm)) != 0) + break; + + /* Can't read a PMC that hasn't been started. */ + if (pm->pm_state != PMC_STATE_ALLOCATED && + pm->pm_state != PMC_STATE_STOPPED && + pm->pm_state != PMC_STATE_RUNNING) { + error = EINVAL; + break; + } + + /* writing a new value is allowed only for 'STOPPED' pmcs */ + if (pm->pm_state == PMC_STATE_RUNNING && + (prw.pm_flags & PMC_F_NEWVALUE)) { + error = EBUSY; + break; + } + + if (PMC_IS_VIRTUAL_MODE(pm->pm_mode)) { + + /* read/write the saved value in the PMC record */ + mtx_pool_lock_spin(pmc_mtxpool, pm); + if (prw.pm_flags & PMC_F_OLDVALUE) + oldvalue = pm->pm_gv.pm_savedvalue; + if (prw.pm_flags & PMC_F_NEWVALUE) + pm->pm_gv.pm_savedvalue = prw.pm_value; + mtx_pool_unlock_spin(pmc_mtxpool, pm); + + } else { /* System mode PMCs */ + cpu = pm->pm_gv.pm_cpu; + ri = pm->pm_rowindex; + + if (pmc_cpu_is_disabled(cpu)) { + error = ENXIO; + break; + } + + /* move this thread to CPU 'cpu' */ + pmc_save_cpu_binding(&pb); + pmc_select_cpu(cpu); + + /* save old value */ + if (prw.pm_flags & PMC_F_OLDVALUE) + if ((error = (*md->pmd_read_pmc)(cpu, ri, + &oldvalue))) + goto error; + /* write out new value */ + if (prw.pm_flags & PMC_F_NEWVALUE) + error = (*md->pmd_write_pmc)(cpu, ri, + prw.pm_value); + error: + pmc_restore_cpu_binding(&pb); + if (error) + break; + } + + pprw = (struct pmc_op_pmcrw *) arg; + +#if DEBUG + if (prw.pm_flags & PMC_F_NEWVALUE) + PMCDBG(PMC,OPS,2, "rw id=%d new %jx -> old %jx", + ri, prw.pm_value, oldvalue); + else + PMCDBG(PMC,OPS,2, "rw id=%d -> old %jx", ri, oldvalue); +#endif + + /* return old value if requested */ + if (prw.pm_flags & PMC_F_OLDVALUE) + if ((error = copyout(&oldvalue, &pprw->pm_value, + sizeof(prw.pm_value)))) + break; + + /* + * send a signal (SIGIO) to the owner if it is trying to read + * a PMC with no target processes attached. + */ + + if (LIST_EMPTY(&pm->pm_targets) && + (prw.pm_flags & PMC_F_OLDVALUE)) { + PROC_LOCK(curthread->td_proc); + psignal(curthread->td_proc, SIGIO); + PROC_UNLOCK(curthread->td_proc); + } + } + break; + + + /* + * Set the sampling rate for a sampling mode PMC and the + * initial count for a counting mode PMC. + */ + + case PMC_OP_PMCSETCOUNT: + { + struct pmc *pm; + struct pmc_op_pmcsetcount sc; + + PMC_DOWNGRADE_SX(); + + if ((error = copyin(arg, &sc, sizeof(sc))) != 0) + break; + + if ((error = pmc_find_pmc(sc.pm_pmcid, &pm)) != 0) + break; + + if (pm->pm_state == PMC_STATE_RUNNING) { + error = EBUSY; + break; + } + + if (PMC_IS_SAMPLING_MODE(pm->pm_mode)) + pm->pm_sc.pm_reloadcount = sc.pm_count; + else + pm->pm_sc.pm_initial = sc.pm_count; + } + break; + + + /* + * Start a PMC. + */ + + case PMC_OP_PMCSTART: + { + pmc_id_t pmcid; + struct pmc *pm; + struct pmc_op_simple sp; + + sx_assert(&pmc_sx, SX_XLOCKED); + + if ((error = copyin(arg, &sp, sizeof(sp))) != 0) + break; + + pmcid = sp.pm_pmcid; + + if ((error = pmc_find_pmc(pmcid, &pm)) != 0) + break; + + KASSERT(pmcid == pm->pm_rowindex, + ("[pmc,%d] row index %d != id %d", __LINE__, + pm->pm_rowindex, pmcid)); + + if (pm->pm_state == PMC_STATE_RUNNING) /* already running */ + break; + else if (pm->pm_state != PMC_STATE_STOPPED && + pm->pm_state != PMC_STATE_ALLOCATED) { + error = EINVAL; + break; + } + + error = pmc_start(pm); + } + break; + + + /* + * Stop a PMC. + */ + + case PMC_OP_PMCSTOP: + { + pmc_id_t pmcid; + struct pmc *pm; + struct pmc_op_simple sp; + + PMC_DOWNGRADE_SX(); + + if ((error = copyin(arg, &sp, sizeof(sp))) != 0) + break; + + pmcid = sp.pm_pmcid; + + /* + * Mark the PMC as inactive and invoke the MD stop + * routines if needed. + */ + + if ((error = pmc_find_pmc(pmcid, &pm)) != 0) + break; + + KASSERT(pmcid == pm->pm_rowindex, + ("[pmc,%d] row index %d != pmcid %d", __LINE__, + pm->pm_rowindex, pmcid)); + + if (pm->pm_state == PMC_STATE_STOPPED) /* already stopped */ + break; + else if (pm->pm_state != PMC_STATE_RUNNING) { + error = EINVAL; + break; + } + + error = pmc_stop(pm); + } + break; + + + /* + * Write a user-entry to the log file. + */ + + case PMC_OP_WRITELOG: + { + + PMC_DOWNGRADE_SX(); + + /* + * flush all per-cpu hash tables + * append user-log entry + */ + + error = ENOSYS; + } + break; + + +#if __i386__ || __amd64__ + + /* + * Machine dependent operation for i386-class processors. + * + * Retrieve the MSR number associated with the counter + * 'pmc_id'. This allows processes to directly use RDPMC + * instructions to read their PMCs, without the overhead of a + * system call. + */ + + case PMC_OP_PMCX86GETMSR: + { + int ri; + struct pmc *pm; + struct pmc_op_x86_getmsr gm; + + PMC_DOWNGRADE_SX(); + + /* CPU has no 'GETMSR' support */ + if (md->pmd_get_msr == NULL) { + error = ENOSYS; + break; + } + + if ((error = copyin(arg, &gm, sizeof(gm))) != 0) + break; + + if ((error = pmc_find_pmc(gm.pm_pmcid, &pm)) != 0) + break; + + /* + * The allocated PMC needs to be a process virtual PMC, + * i.e., of type T[CS]. + * + * Global PMCs can only be read using the PMCREAD + * operation since they may be allocated on a + * different CPU than the one we could be running on + * at the time of the read. + */ + + if (!PMC_IS_VIRTUAL_MODE(pm->pm_mode)) { + error = EINVAL; + break; + } + + ri = pm->pm_rowindex; + + if ((error = (*md->pmd_get_msr)(ri, &gm.pm_msr)) < 0) + break; + if ((error = copyout(&gm, arg, sizeof(gm))) < 0) + break; + } + break; +#endif + + default: + error = EINVAL; + break; + } + + if (is_sx_downgraded) + sx_sunlock(&pmc_sx); + else + sx_xunlock(&pmc_sx); + + if (error) + atomic_add_int(&pmc_stats.pm_syscall_errors, 1); + + return error; +} + +/* + * Helper functions + */ + +/* + * Configure a log file. + */ + +static int +pmc_configure_log(struct pmc_owner *po, int logfd) +{ + struct proc *p; + + return ENOSYS; /* for now */ + + p = po->po_owner; + + if (po->po_logfd < 0 && logfd < 0) /* nothing to do */ + return 0; + + if (po->po_logfd >= 0 && logfd < 0) { + /* deconfigure log */ + /* XXX */ + po->po_flags &= ~PMC_FLAG_OWNS_LOGFILE; + pmc_maybe_remove_owner(po); + + } else if (po->po_logfd < 0 && logfd >= 0) { + /* configure log file */ + /* XXX */ + po->po_flags |= PMC_FLAG_OWNS_LOGFILE; + + /* mark process as using HWPMCs */ + PROC_LOCK(p); + p->p_flag |= P_HWPMC; + PROC_UNLOCK(p); + } else + return EBUSY; + + return 0; +} + +/* + * Log an exit event to the PMC owner's log file. + */ + +static void +pmc_log_process_exit(struct pmc *pm, struct pmc_process *pp) +{ + KASSERT(pm->pm_flags & PMC_F_LOG_TC_PROCEXIT, + ("[pmc,%d] log-process-exit called gratuitously", __LINE__)); + + (void) pm; + (void) pp; + + return; +} + +/* + * Event handlers. + */ + +/* + * Handle a process exit. + * + * XXX This eventhandler gets called early in the exit process. + * Consider using a 'hook' invocation from thread_exit() or equivalent + * spot. Another negative is that kse_exit doesn't seem to call + * exit1() [??]. + */ + +static void +pmc_process_exit(void *arg __unused, struct proc *p) +{ + int is_using_hwpmcs; + + PROC_LOCK(p); + is_using_hwpmcs = p->p_flag & P_HWPMC; + PROC_UNLOCK(p); + + if (is_using_hwpmcs) { + PMCDBG(PRC,EXT,1,"process-exit proc=%p (%d, %s)", p, p->p_pid, + p->p_comm); + + PMC_GET_SX_XLOCK(); + (void) pmc_hook_handler(curthread, PMC_FN_PROCESS_EXIT, + (void *) p); + sx_xunlock(&pmc_sx); + } +} + +/* + * Handle a process fork. + * + * If the parent process 'p1' is under HWPMC monitoring, then copy + * over any attached PMCs that have 'do_descendants' semantics. + */ + +static void +pmc_process_fork(void *arg __unused, struct proc *p1, struct proc *p2, + int flags) +{ + int is_using_hwpmcs; + + (void) flags; /* unused parameter */ + + PROC_LOCK(p1); + is_using_hwpmcs = p1->p_flag & P_HWPMC; + PROC_UNLOCK(p1); + + if (is_using_hwpmcs) { + PMCDBG(PMC,FRK,1, "process-fork proc=%p (%d, %s)", p1, + p1->p_pid, p1->p_comm); + PMC_GET_SX_XLOCK(); + (void) pmc_hook_handler(curthread, PMC_FN_PROCESS_FORK, + (void *) p2); + sx_xunlock(&pmc_sx); + } +} + + +/* + * initialization + */ + +static const char *pmc_name_of_pmcclass[] = { +#undef __PMC_CLASS +#define __PMC_CLASS(N) #N , + __PMC_CLASSES() +}; + +static int +pmc_initialize(void) +{ + int error, cpu, n; + struct pmc_binding pb; + + md = NULL; + error = 0; + +#if DEBUG + /* parse debug flags first */ + if (TUNABLE_STR_FETCH(PMC_SYSCTL_NAME_PREFIX "debugflags", + pmc_debugstr, sizeof(pmc_debugstr))) + pmc_debugflags_parse(pmc_debugstr, + pmc_debugstr+strlen(pmc_debugstr)); +#endif + + PMCDBG(MOD,INI,0, "PMC Initialize (version %x)", PMC_VERSION); + + /* + * check sysctl parameters + */ + + if (pmc_hashsize <= 0) { + (void) printf("pmc: sysctl variable \"" + PMC_SYSCTL_NAME_PREFIX "hashsize\" must be greater than " + "zero\n"); + pmc_hashsize = PMC_HASH_SIZE; + } + +#if defined(__i386__) + /* determine the CPU kind. This is i386 specific */ + if (strcmp(cpu_vendor, "AuthenticAMD") == 0) + md = pmc_amd_initialize(); + else if (strcmp(cpu_vendor, "GenuineIntel") == 0) + md = pmc_intel_initialize(); + /* XXX: what about the other i386 CPU manufacturers? */ +#elif defined(__amd64__) + if (strcmp(cpu_vendor, "AuthenticAMD") == 0) + md = pmc_amd_initialize(); +#else /* other architectures */ + md = NULL; +#endif + + if (md == NULL || md->pmd_init == NULL) + return ENOSYS; + + /* allocate space for the per-cpu array */ + MALLOC(pmc_pcpu, struct pmc_cpu **, mp_ncpus * sizeof(struct pmc_cpu *), + M_PMC, M_WAITOK|M_ZERO); + + /* per-cpu 'saved values' for managing process-mode PMCs */ + MALLOC(pmc_pcpu_saved, pmc_value_t *, + sizeof(pmc_value_t) * mp_ncpus * md->pmd_npmc, M_PMC, M_WAITOK); + + /* perform cpu dependent initialization */ + pmc_save_cpu_binding(&pb); + for (cpu = 0; cpu < mp_ncpus; cpu++) { + if (pmc_cpu_is_disabled(cpu)) + continue; + pmc_select_cpu(cpu); + if ((error = md->pmd_init(cpu)) != 0) + break; + } + pmc_restore_cpu_binding(&pb); + + if (error != 0) + return error; + + /* allocate space for the row disposition array */ + pmc_pmcdisp = malloc(sizeof(enum pmc_mode) * md->pmd_npmc, + M_PMC, M_WAITOK|M_ZERO); + + KASSERT(pmc_pmcdisp != NULL, + ("[pmc,%d] pmcdisp allocation returned NULL", __LINE__)); + + /* mark all PMCs as available */ + for (n = 0; n < (int) md->pmd_npmc; n++) + PMC_MARK_ROW_FREE(n); + + /* allocate thread hash tables */ + pmc_ownerhash = hashinit(pmc_hashsize, M_PMC, + &pmc_ownerhashmask); + + pmc_processhash = hashinit(pmc_hashsize, M_PMC, + &pmc_processhashmask); + mtx_init(&pmc_processhash_mtx, "pmc-process-hash", "pmc", MTX_SPIN); + + /* allocate a pool of spin mutexes */ + pmc_mtxpool = mtx_pool_create("pmc", pmc_mtxpool_size, MTX_SPIN); + + PMCDBG(MOD,INI,1, "pmc_ownerhash=%p, mask=0x%lx " + "targethash=%p mask=0x%lx", pmc_ownerhash, pmc_ownerhashmask, + pmc_processhash, pmc_processhashmask); + + /* register process {exit,fork,exec} handlers */ + pmc_exit_tag = EVENTHANDLER_REGISTER(process_exit, + pmc_process_exit, NULL, EVENTHANDLER_PRI_ANY); + pmc_fork_tag = EVENTHANDLER_REGISTER(process_fork, + pmc_process_fork, NULL, EVENTHANDLER_PRI_ANY); + + /* set hook functions */ + pmc_intr = md->pmd_intr; + pmc_hook = pmc_hook_handler; + + if (error == 0) { + printf(PMC_MODULE_NAME ":"); + for (n = 0; n < (int) md->pmd_nclass; n++) + printf(" %s(%d)", + pmc_name_of_pmcclass[md->pmd_classes[n]], + md->pmd_nclasspmcs[n]); + printf("\n"); + } + + return error; +} + +/* prepare to be unloaded */ +static void +pmc_cleanup(void) +{ + int cpu; + struct pmc_ownerhash *ph; + struct pmc_owner *po, *tmp; + struct pmc_binding pb; +#if DEBUG + struct pmc_processhash *prh; +#endif + + PMCDBG(MOD,INI,0, "%s", "cleanup"); + + pmc_intr = NULL; /* no more interrupts please */ + + sx_xlock(&pmc_sx); + if (pmc_hook == NULL) { /* being unloaded already */ + sx_xunlock(&pmc_sx); + return; + } + + pmc_hook = NULL; /* prevent new threads from entering module */ + + /* deregister event handlers */ + EVENTHANDLER_DEREGISTER(process_fork, pmc_fork_tag); + EVENTHANDLER_DEREGISTER(process_exit, pmc_exit_tag); + + /* send SIGBUS to all owner threads, free up allocations */ + if (pmc_ownerhash) + for (ph = pmc_ownerhash; + ph <= &pmc_ownerhash[pmc_ownerhashmask]; + ph++) { + LIST_FOREACH_SAFE(po, ph, po_next, tmp) { + pmc_remove_owner(po); + + /* send SIGBUS to owner processes */ + PMCDBG(MOD,INI,2, "cleanup signal proc=%p " + "(%d, %s)", po->po_owner, + po->po_owner->p_pid, + po->po_owner->p_comm); + + PROC_LOCK(po->po_owner); + psignal(po->po_owner, SIGBUS); + PROC_UNLOCK(po->po_owner); + FREE(po, M_PMC); + } + } + + /* reclaim allocated data structures */ + if (pmc_mtxpool) + mtx_pool_destroy(&pmc_mtxpool); + + mtx_destroy(&pmc_processhash_mtx); + if (pmc_processhash) { +#if DEBUG + struct pmc_process *pp; + + PMCDBG(MOD,INI,3, "%s", "destroy process hash"); + for (prh = pmc_processhash; + prh <= &pmc_processhash[pmc_processhashmask]; + prh++) + LIST_FOREACH(pp, prh, pp_next) + PMCDBG(MOD,INI,3, "pid=%d", pp->pp_proc->p_pid); +#endif + + hashdestroy(pmc_processhash, M_PMC, pmc_processhashmask); + pmc_processhash = NULL; + } + + if (pmc_ownerhash) { + PMCDBG(MOD,INI,3, "%s", "destroy owner hash"); + hashdestroy(pmc_ownerhash, M_PMC, pmc_ownerhashmask); + pmc_ownerhash = NULL; + } + + /* do processor dependent cleanup */ + PMCDBG(MOD,INI,3, "%s", "md cleanup"); + if (md) { + pmc_save_cpu_binding(&pb); + for (cpu = 0; cpu < mp_ncpus; cpu++) { + PMCDBG(MOD,INI,1,"pmc-cleanup cpu=%d pcs=%p", + cpu, pmc_pcpu[cpu]); + if (pmc_cpu_is_disabled(cpu)) + continue; + pmc_select_cpu(cpu); + if (pmc_pcpu[cpu]) + (void) md->pmd_cleanup(cpu); + } + FREE(md, M_PMC); + md = NULL; + pmc_restore_cpu_binding(&pb); + } + + /* deallocate per-cpu structures */ + FREE(pmc_pcpu, M_PMC); + pmc_pcpu = NULL; + + FREE(pmc_pcpu_saved, M_PMC); + pmc_pcpu_saved = NULL; + + if (pmc_pmcdisp) { + FREE(pmc_pmcdisp, M_PMC); + pmc_pmcdisp = NULL; + } + + sx_xunlock(&pmc_sx); /* we are done */ +} + +/* + * The function called at load/unload. + */ + +static int +load (struct module *module __unused, int cmd, void *arg __unused) +{ + int error; + + error = 0; + + switch (cmd) { + case MOD_LOAD : + /* initialize the subsystem */ + error = pmc_initialize(); + if (error != 0) + break; + PMCDBG(MOD,INI,1, "syscall=%d ncpus=%d", + pmc_syscall_num, mp_ncpus); + break; + + + case MOD_UNLOAD : + case MOD_SHUTDOWN: + pmc_cleanup(); + PMCDBG(MOD,INI,1, "%s", "unloaded"); + break; + + default : + error = EINVAL; /* XXX should panic(9) */ + break; + } + + return error; +} + +/* memory pool */ +MALLOC_DEFINE(M_PMC, "pmc", "Memory space for the PMC module"); |
