/*
 * Copyright (c) 2011-2019 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
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 *
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 */

#ifndef KPERF_H
#define KPERF_H

#include <kern/thread.h>
#include <kern/locks.h>

extern lck_grp_t kperf_lck_grp;

/* the trigger types supported by kperf */
#define TRIGGER_TYPE_TIMER     (0)
#define TRIGGER_TYPE_PMI       (1)
#define TRIGGER_TYPE_KDEBUG    (2)
#define TRIGGER_TYPE_LAZY_WAIT (3)
#define TRIGGER_TYPE_LAZY_CPU  (3)

uint32_t kperf_get_thread_ast(thread_t thread);
void kperf_set_thread_ast(thread_t thread, uint32_t flags);

/*
 * Get and set dirtiness of thread, so kperf can track whether the thread
 * has been dispatched since it last looked.
 */
boolean_t kperf_thread_get_dirty(thread_t thread);
void kperf_thread_set_dirty(thread_t thread, boolean_t dirty);

/*
 * Initialize the rest of kperf lazily, upon first use.  May be called multiple times.
 * The ktrace_lock must be held.
 */
void kperf_setup(void);

/*
 * Configure kperf during boot and check the boot args.
 */
extern void kperf_init_early(void);

bool kperf_is_sampling(void);
int kperf_enable_sampling(void);
int kperf_disable_sampling(void);
int kperf_port_to_pid(mach_port_name_t portname);

/* get a per-CPU sample buffer */
struct kperf_sample *kperf_intr_sample_buffer(void);

enum kperf_sampling {
	KPERF_SAMPLING_OFF,
	KPERF_SAMPLING_SHUTDOWN,
	KPERF_SAMPLING_ON,
};

extern enum kperf_sampling _Atomic kperf_status;

#pragma mark - external callbacks

/*
 * Set up kperf during system startup.
 */
void kperf_init(void);

/*
 * kperf AST handler
 *
 * Prevent inlining, since the sampling function allocates on the stack and
 * branches calling ast_taken (but never on a kperf AST) may blow their stacks.
 */
extern __attribute__((noinline)) void kperf_thread_ast_handler(thread_t thread);

/*
 * Update whether the on-CPU callback should be called.
 */
void kperf_on_cpu_update(void);

/*
 * Should only be called by the scheduler when `thread` is switching on-CPU.
 */
static inline void
kperf_on_cpu(thread_t thread, thread_continue_t continuation,
    uintptr_t *starting_fp)
{
	extern boolean_t kperf_on_cpu_active;
	void kperf_on_cpu_internal(thread_t thread, thread_continue_t continuation,
	    uintptr_t *starting_fp);

	if (__improbable(kperf_on_cpu_active)) {
		kperf_on_cpu_internal(thread, continuation, starting_fp);
	}
}

/*
 * Should only be called by the scheduler when `thread` is switching off-CPU.
 */
static inline void
kperf_off_cpu(thread_t thread)
{
	extern unsigned int kperf_lazy_cpu_action;
	void kperf_lazy_off_cpu(thread_t thread);

	if (__improbable(kperf_lazy_cpu_action != 0)) {
		kperf_lazy_off_cpu(thread);
	}
}

/*
 * Should only be called by the scheduler when `thread` is made runnable.
 */
static inline void
kperf_make_runnable(thread_t thread, int interrupt)
{
	extern unsigned int kperf_lazy_cpu_action;
	void kperf_lazy_make_runnable(thread_t thread, bool interrupt);

	if (__improbable(kperf_lazy_cpu_action != 0)) {
		kperf_lazy_make_runnable(thread, interrupt);
	}
}

static inline void
kperf_running_setup(processor_t processor, uint64_t now)
{
	if (kperf_is_sampling()) {
		extern void kptimer_running_setup(processor_t, uint64_t now);
		kptimer_running_setup(processor, now);
	}
}

/*
 * Should only be called by platform code at the end of each interrupt.
 */
static inline void
kperf_interrupt(void)
{
	extern unsigned int kperf_lazy_cpu_action;
	extern void kperf_lazy_cpu_sample(thread_t thread, unsigned int flags,
	    bool interrupt);

	if (__improbable(kperf_lazy_cpu_action != 0)) {
		kperf_lazy_cpu_sample(NULL, 0, true);
	}
}

/*
 * Should only be called by kdebug when an event with `debugid` is emitted
 * from the frame starting at `starting_fp`.
 */
static inline void
kperf_kdebug_callback(uint32_t debugid, uintptr_t *starting_fp)
{
	extern boolean_t kperf_kdebug_active;
	void kperf_kdebug_handler(uint32_t debugid, uintptr_t *starting_fp);

	if (__improbable(kperf_kdebug_active)) {
		kperf_kdebug_handler(debugid, starting_fp);
	}
}

/*
 * Should only be called by platform code to indicate kperf's per-CPU timer
 * has expired on the current CPU `cpuid` at time `now`.
 */
void kperf_timer_expire(void *param0, void *param1);

/*
 * Used by ktrace to reset kperf.  ktrace_lock must be held.
 */
extern void kperf_reset(void);

/*
 * Configure kperf from the kernel (e.g. during boot).
 */
void kperf_kernel_configure(const char *config);

#endif /* !defined(KPERF_H) */