Revision 0da2f0f164f098bb4447c714b552ac1681b2d6e8 authored by Yoann Padioleau on 06 July 2007, 09:39:56 UTC, committed by Linus Torvalds on 06 July 2007, 17:23:43 UTC
In 7d12e780e003f93433d49ce78cfedf4b4c52adc5 David Howells performed this evolution: "IRQ: Maintain regs pointer globally rather than passing to IRQ handlers" He correctly updated many of the function definitions that were using this extra regs pointer parameter but forgot to update some caller sites of those functions. The reason the modifications was not properly done on all drivers is that some drivers were rarely compiled because they are for AMIGA, or that some code sites were inside #ifdefs where the option is not set or inside #if 0. Here is the semantic patch that found the occurences and fixed the problem. @ rule1 @ identifier fn; identifier irq, dev_id; typedef irqreturn_t; @@ static irqreturn_t fn(int irq, void *dev_id) { ... } @@ identifier rule1.fn; expression E1, E2, E3; @@ fn(E1, E2 - ,E3 ) Signed-off-by: Yoann Padioleau <padator@wanadoo.fr> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Garzik <jeff@garzik.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 071922c
semaphore-sleepers.c
/*
* i386 and x86-64 semaphore implementation.
*
* (C) Copyright 1999 Linus Torvalds
*
* Portions Copyright 1999 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
*/
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/init.h>
#include <asm/semaphore.h>
/*
* Semaphores are implemented using a two-way counter:
* The "count" variable is decremented for each process
* that tries to acquire the semaphore, while the "sleeping"
* variable is a count of such acquires.
*
* Notably, the inline "up()" and "down()" functions can
* efficiently test if they need to do any extra work (up
* needs to do something only if count was negative before
* the increment operation.
*
* "sleeping" and the contention routine ordering is protected
* by the spinlock in the semaphore's waitqueue head.
*
* Note that these functions are only called when there is
* contention on the lock, and as such all this is the
* "non-critical" part of the whole semaphore business. The
* critical part is the inline stuff in <asm/semaphore.h>
* where we want to avoid any extra jumps and calls.
*/
/*
* Logic:
* - only on a boundary condition do we need to care. When we go
* from a negative count to a non-negative, we wake people up.
* - when we go from a non-negative count to a negative do we
* (a) synchronize with the "sleeper" count and (b) make sure
* that we're on the wakeup list before we synchronize so that
* we cannot lose wakeup events.
*/
fastcall void __up(struct semaphore *sem)
{
wake_up(&sem->wait);
}
fastcall void __sched __down(struct semaphore * sem)
{
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_UNINTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* the wait_queue_head.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_UNINTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
}
fastcall int __sched __down_interruptible(struct semaphore * sem)
{
int retval = 0;
struct task_struct *tsk = current;
DECLARE_WAITQUEUE(wait, tsk);
unsigned long flags;
tsk->state = TASK_INTERRUPTIBLE;
spin_lock_irqsave(&sem->wait.lock, flags);
add_wait_queue_exclusive_locked(&sem->wait, &wait);
sem->sleepers++;
for (;;) {
int sleepers = sem->sleepers;
/*
* With signals pending, this turns into
* the trylock failure case - we won't be
* sleeping, and we* can't get the lock as
* it has contention. Just correct the count
* and exit.
*/
if (signal_pending(current)) {
retval = -EINTR;
sem->sleepers = 0;
atomic_add(sleepers, &sem->count);
break;
}
/*
* Add "everybody else" into it. They aren't
* playing, because we own the spinlock in
* wait_queue_head. The "-1" is because we're
* still hoping to get the semaphore.
*/
if (!atomic_add_negative(sleepers - 1, &sem->count)) {
sem->sleepers = 0;
break;
}
sem->sleepers = 1; /* us - see -1 above */
spin_unlock_irqrestore(&sem->wait.lock, flags);
schedule();
spin_lock_irqsave(&sem->wait.lock, flags);
tsk->state = TASK_INTERRUPTIBLE;
}
remove_wait_queue_locked(&sem->wait, &wait);
wake_up_locked(&sem->wait);
spin_unlock_irqrestore(&sem->wait.lock, flags);
tsk->state = TASK_RUNNING;
return retval;
}
/*
* Trylock failed - make sure we correct for
* having decremented the count.
*
* We could have done the trylock with a
* single "cmpxchg" without failure cases,
* but then it wouldn't work on a 386.
*/
fastcall int __down_trylock(struct semaphore * sem)
{
int sleepers;
unsigned long flags;
spin_lock_irqsave(&sem->wait.lock, flags);
sleepers = sem->sleepers + 1;
sem->sleepers = 0;
/*
* Add "everybody else" and us into it. They aren't
* playing, because we own the spinlock in the
* wait_queue_head.
*/
if (!atomic_add_negative(sleepers, &sem->count)) {
wake_up_locked(&sem->wait);
}
spin_unlock_irqrestore(&sem->wait.lock, flags);
return 1;
}
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