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Augment wait queue support in the LinuxKPI.

Browse Source 
In particular:
- Don't evaluate event conditions with a sleepqueue lock held, since such
  code may attempt to acquire arbitrary locks.
- Fix the return value for wait_event_interruptible() in the case that the
  wait is interrupted by a signal.
- Implement wait_on_bit_timeout() and wait_on_atomic_t().
- Implement some functions used to test for pending signals.
- Implement a number of wait_event_*() variants and unify the existing
  implementations.
- Unify the mechanism used by wait_event_*() and schedule() to put the
  calling thread to sleep.

This is required to support updated DRM drivers. Thanks to hselasky for
finding and fixing a number of bugs in the original revision.

Reviewed by:	hselasky
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D10986
This commit is contained in:
Mark Johnston 2017-06-09 19:41:12 +00:00
parent 1bece9d562
commit 465659643b
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=319757
6 changed files with 652 additions and 180 deletions
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99
sys/compat/linuxkpi/common/include/linux/sched.h
View File

@ -48,14 +48,13 @@
#include <asm/atomic.h>
#define MAX_SCHEDULE_TIMEOUT LONG_MAX
#define MAX_SCHEDULE_TIMEOUT INT_MAX
#define TASK_RUNNING 0
#define TASK_INTERRUPTIBLE 1
#define TASK_UNINTERRUPTIBLE 2
#define TASK_DEAD 64
#define TASK_WAKEKILL 128
#define TASK_WAKING 256
#define TASK_RUNNING 0x0000
#define TASK_INTERRUPTIBLE 0x0001
#define TASK_UNINTERRUPTIBLE 0x0002
#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
#define TASK_WAKING 0x0100
struct task_struct {
struct thread *task_thread;
@ -89,9 +88,11 @@ struct task_struct {
#define put_pid(x) do { } while (0)
#define current_euid() (curthread->td_ucred->cr_uid)
#define set_current_state(x) \
atomic_store_rel_int((volatile int *)&current->state, (x))
#define __set_current_state(x) current->state = (x)
#define set_task_state(task, x) \
atomic_store_rel_int((volatile int *)&task->state, (x))
#define __set_task_state(task, x) (task->state = (x))
#define set_current_state(x) set_task_state(current, x)
#define __set_current_state(x) __set_task_state(current, x)
static inline void
get_task_struct(struct task_struct *task)
@ -106,53 +107,45 @@ put_task_struct(struct task_struct *task)
linux_free_current(task);
}
#define schedule() \
do { \
void *c; \
\
if (cold || SCHEDULER_STOPPED()) \
break; \
c = curthread; \
sleepq_lock(c); \
if (current->state == TASK_INTERRUPTIBLE || \
current->state == TASK_UNINTERRUPTIBLE) { \
sleepq_add(c, NULL, "task", SLEEPQ_SLEEP, 0); \
sleepq_wait(c, 0); \
} else { \
sleepq_release(c); \
sched_relinquish(curthread); \
} \
} while (0)
#define wake_up_process(x) \
do { \
int wakeup_swapper; \
void *c; \
\
c = (x)->task_thread; \
sleepq_lock(c); \
(x)->state = TASK_RUNNING; \
wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0); \
sleepq_release(c); \
if (wakeup_swapper) \
kick_proc0(); \
} while (0)
#define cond_resched() if (!cold) sched_relinquish(curthread)
#define yield() kern_yield(PRI_UNCHANGED)
#define sched_yield() sched_relinquish(curthread)
static inline long
schedule_timeout(signed long timeout)
{
if (timeout < 0)
return 0;
pause("lstim", timeout);
return 0;
}
#define need_resched() (curthread->td_flags & TDF_NEEDRESCHED)
bool linux_signal_pending(struct task_struct *task);
bool linux_fatal_signal_pending(struct task_struct *task);
bool linux_signal_pending_state(long state, struct task_struct *task);
void linux_send_sig(int signo, struct task_struct *task);
#define signal_pending(task) linux_signal_pending(task)
#define fatal_signal_pending(task) linux_fatal_signal_pending(task)
#define signal_pending_state(state, task) \
linux_signal_pending_state(state, task)
#define send_sig(signo, task, priv) do { \
CTASSERT(priv == 0); \
linux_send_sig(signo, task); \
} while (0)
int linux_schedule_timeout(int timeout);
#define schedule() \
(void)linux_schedule_timeout(MAX_SCHEDULE_TIMEOUT)
#define schedule_timeout(timeout) \
linux_schedule_timeout(timeout)
#define schedule_timeout_killable(timeout) \
schedule_timeout_uninterruptible(timeout)
#define schedule_timeout_interruptible(timeout) ({ \
set_current_state(TASK_INTERRUPTIBLE); \
schedule_timeout(timeout); \
})
#define schedule_timeout_uninterruptible(timeout) ({ \
set_current_state(TASK_UNINTERRUPTIBLE); \
schedule_timeout(timeout); \
})
#define io_schedule() schedule()
#define io_schedule_timeout(timeout) schedule_timeout(timeout)
#endif /* _LINUX_SCHED_H_ */

336
sys/compat/linuxkpi/common/include/linux/wait.h
View File

@ -3,6 +3,7 @@
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
* Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -28,160 +29,243 @@
*
* $FreeBSD$
*/
#ifndef _LINUX_WAIT_H_
#ifndef _LINUX_WAIT_H_
#define _LINUX_WAIT_H_
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sleepqueue.h>
#include <sys/kernel.h>
#include <sys/proc.h>
typedef struct {
} wait_queue_t;
#define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active)
typedef struct {
unsigned int wchan;
} wait_queue_head_t;
#define might_sleep() \
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()")
#define init_waitqueue_head(x) \
do { } while (0)
struct wait_queue;
struct wait_queue_head;
static inline void
__wake_up(wait_queue_head_t *q, int all)
{
int wakeup_swapper;
void *c;
typedef struct wait_queue wait_queue_t;
typedef struct wait_queue_head wait_queue_head_t;
c = &q->wchan;
sleepq_lock(c);
if (all)
wakeup_swapper = sleepq_broadcast(c, SLEEPQ_SLEEP, 0, 0);
else
wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);
sleepq_release(c);
if (wakeup_swapper)
kick_proc0();
}
typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *);
#define wake_up(q) __wake_up(q, 0)
#define wake_up_nr(q, nr) __wake_up(q, 1)
#define wake_up_all(q) __wake_up(q, 1)
#define wake_up_interruptible(q) __wake_up(q, 0)
#define wake_up_interruptible_nr(q, nr) __wake_up(q, 1)
#define wake_up_interruptible_all(q, nr) __wake_up(q, 1)
/*
* Many API consumers directly reference these fields and those of
* wait_queue_head.
*/
struct wait_queue {
unsigned int flags; /* always 0 */
void *private;
wait_queue_func_t *func;
struct list_head task_list;
};
#define wait_event(q, cond) \
do { \
void *c = &(q).wchan; \
if (!(cond)) { \
for (;;) { \
if (SCHEDULER_STOPPED()) \
break; \
sleepq_lock(c); \
if (cond) { \
sleepq_release(c); \
break; \
} \
sleepq_add(c, NULL, "completion", SLEEPQ_SLEEP, 0); \
sleepq_wait(c, 0); \
} \
} \
struct wait_queue_head {
spinlock_t lock;
struct list_head task_list;
};
/*
* This function is referenced by at least one DRM driver, so it may not be
* renamed and furthermore must be the default wait queue callback.
*/
extern wait_queue_func_t autoremove_wake_function;
#define DEFINE_WAIT(name) \
wait_queue_t name = { \
.private = current, \
.func = autoremove_wake_function, \
.task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
}
#define DECLARE_WAITQUEUE(name, task) \
wait_queue_t name = { \
.private = task, \
.task_list = LINUX_LIST_HEAD_INIT(name.task_list) \
}
#define DECLARE_WAIT_QUEUE_HEAD(name) \
wait_queue_head_t name = { \
.task_list = LINUX_LIST_HEAD_INIT(name.task_list), \
}; \
MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF)
#define init_waitqueue_head(wqh) do { \
mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \
NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \
INIT_LIST_HEAD(&(wqh)->task_list); \
} while (0)
#define wait_event_interruptible(q, cond) \
({ \
void *c = &(q).wchan; \
int _error; \
\
_error = 0; \
if (!(cond)) { \
for (; _error == 0;) { \
if (SCHEDULER_STOPPED()) \
break; \
sleepq_lock(c); \
if (cond) { \
sleepq_release(c); \
break; \
} \
sleepq_add(c, NULL, "completion", \
SLEEPQ_SLEEP | SLEEPQ_INTERRUPTIBLE, 0); \
if (sleepq_wait_sig(c, 0)) \
_error = -ERESTARTSYS; \
} \
} \
-_error; \
void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool);
#define wake_up(wqh) \
linux_wake_up(wqh, TASK_NORMAL, 1, false)
#define wake_up_all(wqh) \
linux_wake_up(wqh, TASK_NORMAL, 0, false)
#define wake_up_locked(wqh) \
linux_wake_up(wqh, TASK_NORMAL, 1, true)
#define wake_up_all_locked(wqh) \
linux_wake_up(wqh, TASK_NORMAL, 0, true)
#define wake_up_interruptible(wqh) \
linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false)
#define wake_up_interruptible_all(wqh) \
linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false)
int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int,
unsigned int, spinlock_t *);
/*
* Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if
* cond is true after timeout, remaining jiffies (> 0) if cond is true before
* timeout.
*/
#define __wait_event_common(wqh, cond, timeout, state, lock) ({ \
DEFINE_WAIT(__wq); \
const int __timeout = (timeout) < 1 ? 1 : (timeout); \
int __start = ticks; \
int __ret = 0; \
\
for (;;) { \
linux_prepare_to_wait(&(wqh), &__wq, state); \
if (cond) { \
__ret = 1; \
break; \
} \
__ret = linux_wait_event_common(&(wqh), &__wq, \
__timeout, state, lock); \
if (__ret != 0) \
break; \
} \
linux_finish_wait(&(wqh), &__wq); \
if (__timeout != MAX_SCHEDULE_TIMEOUT) { \
if (__ret == -EWOULDBLOCK) \
__ret = !!(cond); \
else if (__ret != -ERESTARTSYS) { \
__ret = __timeout + __start - ticks; \
/* range check return value */ \
if (__ret < 1) \
__ret = 1; \
else if (__ret > __timeout) \
__ret = __timeout; \
} \
} \
__ret; \
})
#define wait_event_interruptible_timeout(q, cond, timeout) \
({ \
void *c = &(q).wchan; \
long end = jiffies + timeout; \
int __ret = 0; \
int __rc = 0; \
#define wait_event(wqh, cond) ({ \
__wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
TASK_UNINTERRUPTIBLE, NULL); \
})
#define wait_event_timeout(wqh, cond, timeout) ({ \
__wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \
NULL); \
})
#define wait_event_interruptible(wqh, cond) ({ \
__wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
TASK_INTERRUPTIBLE, NULL); \
})
#define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \
__wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \
NULL); \
})
/*
* Wait queue is already locked.
*/
#define wait_event_interruptible_locked(wqh, cond) ({ \
int __ret; \
\
if (!(cond)) { \
for (; __rc == 0;) { \
if (SCHEDULER_STOPPED()) \
break; \
sleepq_lock(c); \
if (cond) { \
sleepq_release(c); \
__ret = 1; \
break; \
} \
sleepq_add(c, NULL, "completion", \
SLEEPQ_SLEEP | SLEEPQ_INTERRUPTIBLE, 0); \
sleepq_set_timeout(c, linux_timer_jiffies_until(end));\
__rc = sleepq_timedwait_sig (c, 0); \
if (__rc != 0) { \
/* check for timeout or signal. \
* 0 if the condition evaluated to false\
* after the timeout elapsed, 1 if the \
* condition evaluated to true after the\
* timeout elapsed. \
*/ \
if (__rc == EWOULDBLOCK) \
__ret = (cond); \
else \
__ret = -ERESTARTSYS; \
} \
\
} \
} else { \
/* return remaining jiffies (at least 1) if the \
* condition evaluated to true before the timeout \
* elapsed. \
*/ \
__ret = (end - jiffies); \
if( __ret < 1 ) \
__ret = 1; \
} \
spin_unlock(&(wqh).lock); \
__ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
TASK_INTERRUPTIBLE, NULL); \
spin_lock(&(wqh).lock); \
__ret; \
})
static inline int
waitqueue_active(wait_queue_head_t *q)
{
return 0; /* XXX: not really implemented */
}
#define DEFINE_WAIT(name) \
wait_queue_t name = {}
/*
* Hold the (locked) spinlock when testing the cond.
*/
#define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \
__wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \
TASK_INTERRUPTIBLE, &(lock)); \
})
static inline void
prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
__add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
{
list_add(&wq->task_list, &wqh->task_list);
}
static inline void
finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
{
spin_lock(&wqh->lock);
__add_wait_queue(wqh, wq);
spin_unlock(&wqh->lock);
}
#endif /* _LINUX_WAIT_H_ */
static inline void
__add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq)
{
list_add_tail(&wq->task_list, &wqh->task_list);
}
static inline void
__remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
{
list_del(&wq->task_list);
}
static inline void
remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq)
{
spin_lock(&wqh->lock);
__remove_wait_queue(wqh, wq);
spin_unlock(&wqh->lock);
}
bool linux_waitqueue_active(wait_queue_head_t *);
#define waitqueue_active(wqh) linux_waitqueue_active(wqh)
void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int);
void linux_finish_wait(wait_queue_head_t *, wait_queue_t *);
#define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state)
#define finish_wait(wqh, wq) linux_finish_wait(wqh, wq)
void linux_wake_up_bit(void *, int);
int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int);
void linux_wake_up_atomic_t(atomic_t *);
int linux_wait_on_atomic_t(atomic_t *, unsigned int);
#define wake_up_bit(word, bit) linux_wake_up_bit(word, bit)
#define wait_on_bit_timeout(word, bit, state, timeout) \
linux_wait_on_bit_timeout(word, bit, state, timeout)
#define wake_up_atomic_t(a) linux_wake_up_atomic_t(a)
/*
* All existing callers have a cb that just schedule()s. To avoid adding
* complexity, just emulate that internally. The prototype is different so that
* callers must be manually modified; a cb that does something other than call
* schedule() will require special treatment.
*/
#define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state)
struct task_struct;
bool linux_wake_up_state(struct task_struct *, unsigned int);
#define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL)
#define wake_up_state(task, state) linux_wake_up_state(task, state)
#endif /* _LINUX_WAIT_H_ */

3
sys/compat/linuxkpi/common/src/linux_kthread.c
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@ -27,9 +27,10 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <linux/compat.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/compat.h>
#include <linux/wait.h>
#include <sys/bus.h>
#include <sys/interrupt.h>

391
sys/compat/linuxkpi/common/src/linux_schedule.c Normal file
View File

@ -0,0 +1,391 @@
/*-
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/sleepqueue.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, const char *wmesg, int timeout, int state)
{
int flags, ret;
MPASS((state & ~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);
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);
}
/* filter return value */
if (ret != 0 && ret != -EWOULDBLOCK)
ret = -ERESTARTSYS;
return (ret);
}
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_load_acq_int(&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);
}
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;
long ret;
if (lock != NULL)
spin_unlock_irq(lock);
DROP_GIANT();
task = current;
/*
* Our wait queue entry is on the stack - make sure it doesn't
* get swapped out while we sleep.
*/
#ifndef NO_SWAPPING
PHOLD(task->task_thread->td_proc);
#endif
sleepq_lock(task);
if (atomic_load_acq_int(&task->state) != TASK_WAKING) {
ret = linux_add_to_sleepqueue(task, "wevent", timeout, state);
} else {
sleepq_release(task);
ret = linux_signal_pending_state(state, task) ? -ERESTARTSYS : 0;
}
#ifndef NO_SWAPPING
PRELE(task->task_thread->td_proc);
#endif
PICKUP_GIANT();
if (lock != NULL)
spin_lock_irq(lock);
return (ret);
}
int
linux_schedule_timeout(int timeout)
{
struct task_struct *task;
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;
DROP_GIANT();
sleepq_lock(task);
state = atomic_load_acq_int(&task->state);
if (state != TASK_WAKING)
(void)linux_add_to_sleepqueue(task, "sched", timeout, state);
else
sleepq_release(task);
set_task_state(task, TASK_RUNNING);
PICKUP_GIANT();
if (timeout == 0)
return (MAX_SCHEDULE_TIMEOUT);
/* range check return value */
remainder -= ticks;
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;
DROP_GIANT();
/* 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, "wbit", timeout, state);
if (ret != 0)
break;
}
set_task_state(task, TASK_RUNNING);
PICKUP_GIANT();
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;
DROP_GIANT();
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, "watomic", 0, state);
if (ret != 0)
break;
}
set_task_state(task, TASK_RUNNING);
PICKUP_GIANT();
return (ret);
}
bool
linux_wake_up_state(struct task_struct *task, unsigned int state)
{
return (wake_up_task(task, state) != 0);
}

2
sys/conf/files
View File

@ -4281,6 +4281,8 @@ compat/linuxkpi/common/src/linux_radix.c optional compat_linuxkpi \
compile-with "${LINUXKPI_C}"
compat/linuxkpi/common/src/linux_rcu.c optional compat_linuxkpi \
compile-with "${LINUXKPI_C} -I$S/contrib/ck/include"
compat/linuxkpi/common/src/linux_schedule.c optional compat_linuxkpi \
compile-with "${LINUXKPI_C}"
compat/linuxkpi/common/src/linux_slab.c optional compat_linuxkpi \
compile-with "${LINUXKPI_C}"
compat/linuxkpi/common/src/linux_usb.c optional compat_linuxkpi usb \

1
sys/modules/linuxkpi/Makefile
View File

@ -11,6 +11,7 @@ SRCS= linux_kmod.c \
linux_pci.c \
linux_radix.c \
linux_rcu.c \
linux_schedule.c \
linux_slab.c \
linux_tasklet.c \
linux_idr.c \