/*-
* Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conds
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conds, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conds and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/sleepqueue.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
static int
linux_add_to_sleepqueue(void *wchan, struct task_struct *task,
const char *wmesg, int timeout, int state)
{
int flags, ret;
MPASS((state & ~(TASK_PARKED | TASK_NORMAL)) == 0);
flags = SLEEPQ_SLEEP | ((state & TASK_INTERRUPTIBLE) != 0 ?
SLEEPQ_INTERRUPTIBLE : 0);
sleepq_add(wchan, NULL, wmesg, flags, 0);
if (timeout != 0)
sleepq_set_timeout(wchan, timeout);
DROP_GIANT();
if ((state & TASK_INTERRUPTIBLE) != 0) {
if (timeout == 0)
ret = -sleepq_wait_sig(wchan, 0);
else
ret = -sleepq_timedwait_sig(wchan, 0);
} else {
if (timeout == 0) {
sleepq_wait(wchan, 0);
ret = 0;
} else
ret = -sleepq_timedwait(wchan, 0);
}
PICKUP_GIANT();
/* filter return value */
if (ret != 0 && ret != -EWOULDBLOCK) {
linux_schedule_save_interrupt_value(task, ret);
ret = -ERESTARTSYS;
}
return (ret);
}
unsigned int
linux_msleep_interruptible(unsigned int ms)
{
int ret;
/* guard against invalid values */
if (ms == 0)
ms = 1;
ret = -pause_sbt("lnxsleep", mstosbt(ms), 0, C_HARDCLOCK | C_CATCH);
switch (ret) {
case -EWOULDBLOCK:
return (0);
default:
linux_schedule_save_interrupt_value(current, ret);
return (ms);
}
}
static int
wake_up_task(struct task_struct *task, unsigned int state)
{
int ret, wakeup_swapper;
ret = wakeup_swapper = 0;
sleepq_lock(task);
if ((atomic_read(&task->state) & state) != 0) {
set_task_state(task, TASK_WAKING);
wakeup_swapper = sleepq_signal(task, SLEEPQ_SLEEP, 0, 0);
ret = 1;
}
sleepq_release(task);
if (wakeup_swapper)
kick_proc0();
return (ret);
}
bool
linux_signal_pending(struct task_struct *task)
{
struct thread *td;
sigset_t pending;
td = task->task_thread;
PROC_LOCK(td->td_proc);
pending = td->td_siglist;
SIGSETOR(pending, td->td_proc->p_siglist);
SIGSETNAND(pending, td->td_sigmask);
PROC_UNLOCK(td->td_proc);
return (!SIGISEMPTY(pending));
}
bool
linux_fatal_signal_pending(struct task_struct *task)
{
struct thread *td;
bool ret;
td = task->task_thread;
PROC_LOCK(td->td_proc);
ret = SIGISMEMBER(td->td_siglist, SIGKILL) ||
SIGISMEMBER(td->td_proc->p_siglist, SIGKILL);
PROC_UNLOCK(td->td_proc);
return (ret);
}
bool
linux_signal_pending_state(long state, struct task_struct *task)
{
MPASS((state & ~TASK_NORMAL) == 0);
if ((state & TASK_INTERRUPTIBLE) == 0)
return (false);
return (linux_signal_pending(task));
}
void
linux_send_sig(int signo, struct task_struct *task)
{
struct thread *td;
td = task->task_thread;
PROC_LOCK(td->td_proc);
tdsignal(td, signo);
PROC_UNLOCK(td->td_proc);
}
int
autoremove_wake_function(wait_queue_t *wq, unsigned int state, int flags,
void *key __unused)
{
struct task_struct *task;
int ret;
task = wq->private;
if ((ret = wake_up_task(task, state)) != 0)
list_del_init(&wq->task_list);
return (ret);
}
int
default_wake_function(wait_queue_t *wq, unsigned int state, int flags,
void *key __unused)
{
return (wake_up_task(wq->private, state));
}
void
linux_init_wait_entry(wait_queue_t *wq, int flags)
{
memset(wq, 0, sizeof(*wq));
wq->flags = flags;
wq->private = current;
wq->func = autoremove_wake_function;
INIT_LIST_HEAD(&wq->task_list);
}
void
linux_wake_up(wait_queue_head_t *wqh, unsigned int state, int nr, bool locked)
{
wait_queue_t *pos, *next;
if (!locked)
spin_lock(&wqh->lock);
list_for_each_entry_safe(pos, next, &wqh->task_list, task_list) {
if (pos->func == NULL) {
if (wake_up_task(pos->private, state) != 0 && --nr == 0)
break;
} else {
if (pos->func(pos, state, 0, NULL) != 0 && --nr == 0)
break;
}
}
if (!locked)
spin_unlock(&wqh->lock);
}
void
linux_prepare_to_wait(wait_queue_head_t *wqh, wait_queue_t *wq, int state)
{
spin_lock(&wqh->lock);
if (list_empty(&wq->task_list))
__add_wait_queue(wqh, wq);
set_task_state(current, state);
spin_unlock(&wqh->lock);
}
void
linux_finish_wait(wait_queue_head_t *wqh, wait_queue_t *wq)
{
spin_lock(&wqh->lock);
set_task_state(current, TASK_RUNNING);
if (!list_empty(&wq->task_list)) {
__remove_wait_queue(wqh, wq);
INIT_LIST_HEAD(&wq->task_list);
}
spin_unlock(&wqh->lock);
}
bool
linux_waitqueue_active(wait_queue_head_t *wqh)
{
bool ret;
spin_lock(&wqh->lock);
ret = !list_empty(&wqh->task_list);
spin_unlock(&wqh->lock);
return (ret);
}
int
linux_wait_event_common(wait_queue_head_t *wqh, wait_queue_t *wq, int timeout,
unsigned int state, spinlock_t *lock)
{
struct task_struct *task;
int ret;
if (lock != NULL)
spin_unlock_irq(lock);
/* range check timeout */
if (timeout < 1)
timeout = 1;
else if (timeout == MAX_SCHEDULE_TIMEOUT)
timeout = 0;
task = current;
/*
* Our wait queue entry is on the stack - make sure it doesn't
* get swapped out while we sleep.
*/
PHOLD(task->task_thread->td_proc);
sleepq_lock(task);
if (atomic_read(&task->state) != TASK_WAKING) {
ret = linux_add_to_sleepqueue(task, task, "wevent", timeout,
state);
} else {
sleepq_release(task);
ret = 0;
}
PRELE(task->task_thread->td_proc);
if (lock != NULL)
spin_lock_irq(lock);
return (ret);
}
int
linux_schedule_timeout(int timeout)
{
struct task_struct *task;
int ret;
int state;
int remainder;
task = current;
/* range check timeout */
if (timeout < 1)
timeout = 1;
else if (timeout == MAX_SCHEDULE_TIMEOUT)
timeout = 0;
remainder = ticks + timeout;
sleepq_lock(task);
state = atomic_read(&task->state);
if (state != TASK_WAKING) {
ret = linux_add_to_sleepqueue(task, task, "sched", timeout,
state);
} else {
sleepq_release(task);
ret = 0;
}
set_task_state(task, TASK_RUNNING);
if (timeout == 0)
return (MAX_SCHEDULE_TIMEOUT);
/* range check return value */
remainder -= ticks;
/* range check return value */
if (ret == -ERESTARTSYS && remainder < 1)
remainder = 1;
else if (remainder < 0)
remainder = 0;
else if (remainder > timeout)
remainder = timeout;
return (remainder);
}
static void
wake_up_sleepers(void *wchan)
{
int wakeup_swapper;
sleepq_lock(wchan);
wakeup_swapper = sleepq_signal(wchan, SLEEPQ_SLEEP, 0, 0);
sleepq_release(wchan);
if (wakeup_swapper)
kick_proc0();
}
#define bit_to_wchan(word, bit) ((void *)(((uintptr_t)(word) << 6) | (bit)))
void
linux_wake_up_bit(void *word, int bit)
{
wake_up_sleepers(bit_to_wchan(word, bit));
}
int
linux_wait_on_bit_timeout(unsigned long *word, int bit, unsigned int state,
int timeout)
{
struct task_struct *task;
void *wchan;
int ret;
/* range check timeout */
if (timeout < 1)
timeout = 1;
else if (timeout == MAX_SCHEDULE_TIMEOUT)
timeout = 0;
task = current;
wchan = bit_to_wchan(word, bit);
for (;;) {
sleepq_lock(wchan);
if ((*word & (1 << bit)) == 0) {
sleepq_release(wchan);
ret = 0;
break;
}
set_task_state(task, state);
ret = linux_add_to_sleepqueue(wchan, task, "wbit", timeout,
state);
if (ret != 0)
break;
}
set_task_state(task, TASK_RUNNING);
return (ret);
}
void
linux_wake_up_atomic_t(atomic_t *a)
{
wake_up_sleepers(a);
}
int
linux_wait_on_atomic_t(atomic_t *a, unsigned int state)
{
struct task_struct *task;
void *wchan;
int ret;
task = current;
wchan = a;
for (;;) {
sleepq_lock(wchan);
if (atomic_read(a) == 0) {
sleepq_release(wchan);
ret = 0;
break;
}
set_task_state(task, state);
ret = linux_add_to_sleepqueue(wchan, task, "watomic", 0, state);
if (ret != 0)
break;
}
set_task_state(task, TASK_RUNNING);
return (ret);
}
bool
linux_wake_up_state(struct task_struct *task, unsigned int state)
{
return (wake_up_task(task, state) != 0);
}
