/* $NetBSD: lockstat.h,v 1.15 2022/02/27 14:16:12 riastradh Exp $ */

/* $NetBSD: lockstat.h,v 1.15 2022/02/27 14:16:12 riastradh Exp $ */

/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#ifndef _SYS_LOCKSTAT_H_
#define _SYS_LOCKSTAT_H_

#ifdef _KERNEL_OPT
#include "opt_dtrace.h"
#include <lockstat.h>
#endif

#include <sys/types.h>

#include <sys/ioccom.h>
#include <sys/lock.h>
#include <sys/queue.h>
#include <sys/time.h>

#if defined(_KERNEL) && defined(__HAVE_CPU_COUNTER)
#include <machine/cpu_counter.h>
#endif

/*
* Interface version. The interface is not designed to provide
* compatibility across NetBSD releases.
*/

#define IOC_LOCKSTAT_GVERSION _IOR('L', 0, int)

#define LS_VERSION 5

/*
* Enable request. We can limit tracing by the call site and by
* the lock. We also specify the number of event buffers to
* allocate up front, and what kind of events to track.
*/

#define IOC_LOCKSTAT_ENABLE _IOW('L', 1, lsenable_t)

#define LE_CALLSITE 0x01 /* track call sites */
#define LE_ONE_CALLSITE 0x02 /* specific call site */
#define LE_ONE_LOCK 0x04 /* specific lock */
#define LE_LOCK 0x08 /* track locks */

typedef struct lsenable {
uintptr_t le_csstart; /* callsite start */
uintptr_t le_csend; /* callsite end */
uintptr_t le_lockstart; /* lock address start */
uintptr_t le_lockend; /* lock address end */
uintptr_t le_nbufs; /* buffers to allocate, 0 = default */
u_int le_flags; /* request flags */
u_int le_mask; /* event mask (LB_*) */
} lsenable_t;

/*
* Disable request.
*/

#define IOC_LOCKSTAT_DISABLE _IOR('L', 2, lsdisable_t)

typedef struct lsdisable {
size_t ld_size; /* buffer space allocated */
struct timespec ld_time; /* time spent enabled */
uint64_t ld_freq[64]; /* counter HZ by CPU number */
} lsdisable_t;

/*
* Event buffers returned from reading from the devices.
*/

/*
* Event types, for lockstat_event(). Stored in lb_flags but should be
* meaningless to the consumer, also provided with the enable request
* in le_mask.
*/
#define LB_SPIN 0x00000001
#define LB_SLEEP1 0x00000002
#define LB_SLEEP2 0x00000003
#define LB_NEVENT 0x00000003
#define LB_EVENT_MASK 0x000000ff

/*
* Lock types, the only part of lb_flags that should be inspected. Also
* provided with the enable request in le_mask.
*/
#define LB_ADAPTIVE_MUTEX 0x00000100
#define LB_SPIN_MUTEX 0x00000200
#define LB_RWLOCK 0x00000300
#define LB_NOPREEMPT 0x00000400
#define LB_KERNEL_LOCK 0x00000500
#define LB_MISC 0x00000600
#define LB_NLOCK 0x00000600
#define LB_LOCK_MASK 0x0000ff00
#define LB_LOCK_SHIFT 8

#define LB_DTRACE 0x00010000

typedef struct lsbuf {
union {
LIST_ENTRY(lsbuf) list;
SLIST_ENTRY(lsbuf) slist;
TAILQ_ENTRY(lsbuf) tailq;
} lb_chain;
uintptr_t lb_lock; /* lock address */
uintptr_t lb_callsite; /* call site */
uint64_t lb_times[LB_NEVENT]; /* cumulative times */
uint32_t lb_counts[LB_NEVENT]; /* count of events */
uint16_t lb_flags; /* lock type */
uint16_t lb_cpu; /* CPU number */
} lsbuf_t;

/*
* Tracing stubs used by lock providers.
*/

#if defined(_KERNEL) && defined(__HAVE_CPU_COUNTER) && NLOCKSTAT > 0

#define LOCKSTAT_EVENT(flag, lock, type, count, time) \
do { \
if (__predict_false(flag)) \
lockstat_event((uintptr_t)(lock), \
(uintptr_t)__builtin_return_address(0), \
(type), (count), (time)); \
} while (/* CONSTCOND */ 0);

#define LOCKSTAT_EVENT_RA(flag, lock, type, count, time, ra) \
do { \
if (__predict_false(flag)) \
lockstat_event((uintptr_t)(lock), (uintptr_t)ra, \
(type), (count), (time)); \
} while (/* CONSTCOND */ 0);

#define LOCKSTAT_TIMER(name) uint64_t name = 0
#define LOCKSTAT_COUNTER(name) uint64_t name = 0
#define LOCKSTAT_FLAG(name) int name
#define LOCKSTAT_ENTER(name) name = atomic_load_relaxed(&lockstat_enabled)
#define LOCKSTAT_EXIT(name)

#define LOCKSTAT_START_TIMER(flag, name) \
do { \
if (__predict_false(flag)) \
(name) -= cpu_counter(); \
} while (/* CONSTCOND */ 0)

#define LOCKSTAT_STOP_TIMER(flag, name) \
do { \
if (__predict_false(flag)) \
(name) += cpu_counter(); \
} while (/* CONSTCOND */ 0)

#define LOCKSTAT_COUNT(name, inc) \
do { \
(name) += (inc); \
} while (/* CONSTCOND */ 0)

void lockstat_event(uintptr_t, uintptr_t, u_int, u_int, uint64_t);

#else

#define LOCKSTAT_FLAG(name) /* nothing */
#define LOCKSTAT_ENTER(name) /* nothing */
#define LOCKSTAT_EXIT(name) /* nothing */
#define LOCKSTAT_EVENT(flag, lock, type, count, time) /* nothing */
#define LOCKSTAT_EVENT_RA(flag, lock, type, count, time, ra) /* nothing */
#define LOCKSTAT_TIMER(void) /* nothing */
#define LOCKSTAT_COUNTER(void) /* nothing */
#define LOCKSTAT_START_TIMER(flag, void) /* nothing */
#define LOCKSTAT_STOP_TIMER(flag, void) /* nothing */
#define LOCKSTAT_COUNT(name, int) /* nothing */

#endif

#ifdef KDTRACE_HOOKS
extern volatile u_int lockstat_dtrace_enabled;
#define KDTRACE_LOCKSTAT_ENABLED lockstat_dtrace_enabled
#define LS_COMPRESS(f) \
((((f) & 0x3) | (((f) & 0x700) >> 6)) & (LS_NPROBES - 1))
#define LS_NPROBES 0x20 /* 5 bits */

extern uint32_t lockstat_probemap[];
extern void (*lockstat_probe_func)(uint32_t, uintptr_t, uintptr_t,
uintptr_t, uintptr_t, uintptr_t);

void lockstat_probe_stub(uint32_t, uintptr_t, uintptr_t,
uintptr_t, uintptr_t, uintptr_t);
#else
#define KDTRACE_LOCKSTAT_ENABLED 0
#endif

#if defined(_KERNEL) && NLOCKSTAT > 0
extern __cpu_simple_lock_t lockstat_enabled_lock;
extern volatile u_int lockstat_enabled;
extern volatile u_int lockstat_dev_enabled;

#define LOCKSTAT_ENABLED_UPDATE_BEGIN() do \
{ \
__cpu_simple_lock(&lockstat_enabled_lock); \
} while (/*CONSTCOND*/0)

#define LOCKSTAT_ENABLED_UPDATE_END() do \
{ \
atomic_store_relaxed(&lockstat_enabled, \
lockstat_dev_enabled | KDTRACE_LOCKSTAT_ENABLED); \
__cpu_simple_unlock(&lockstat_enabled_lock); \
} while (/*CONSTCOND*/0)

#endif

#endif /* _SYS_LOCKSTAT_H_ */