Add down_timeout and change ACPI to use it (f1241c87) · Commits · 戴 / test

drivers/acpi/osl.c

+21 −68

Original line number	Diff line number	Diff line
		@@ -4,6 +4,8 @@
		* Copyright (C) 2000 Andrew Henroid
		* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
		* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
		* Copyright (c) 2008 Intel Corporation
		* Author: Matthew Wilcox <willy@linux.intel.com>
		*
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		*
		@@ -37,15 +39,18 @@
		#include <linux/workqueue.h>
		#include <linux/nmi.h>
		#include <linux/acpi.h>
		#include <acpi/acpi.h>
		#include <asm/io.h>
		#include <acpi/acpi_bus.h>
		#include <acpi/processor.h>
		#include <asm/uaccess.h>

		#include <linux/efi.h>
		#include <linux/ioport.h>
		#include <linux/list.h>
		#include <linux/jiffies.h>
		#include <linux/semaphore.h>

		#include <asm/io.h>
		#include <asm/uaccess.h>

		#include <acpi/acpi.h>
		#include <acpi/acpi_bus.h>
		#include <acpi/processor.h>

		#define _COMPONENT ACPI_OS_SERVICES
		ACPI_MODULE_NAME("osl");
		@@ -764,7 +769,6 @@ acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
		{
		struct semaphore *sem = NULL;


		sem = acpi_os_allocate(sizeof(struct semaphore));
		if (!sem)
		return AE_NO_MEMORY;
		@@ -791,12 +795,12 @@ acpi_status acpi_os_delete_semaphore(acpi_handle handle)
		{
		struct semaphore sem = (struct semaphore )handle;


		if (!sem)
		return AE_BAD_PARAMETER;

		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));

		BUG_ON(!list_empty(&sem->wait_list));
		kfree(sem);
		sem = NULL;

		@@ -804,21 +808,15 @@ acpi_status acpi_os_delete_semaphore(acpi_handle handle)
		}

		/*
		* TODO: The kernel doesn't have a 'down_timeout' function -- had to
		* improvise. The process is to sleep for one scheduler quantum
		* until the semaphore becomes available. Downside is that this
		* may result in starvation for timeout-based waits when there's
		* lots of semaphore activity.
		*
		* TODO: Support for units > 1?
		*/
		acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
		{
		acpi_status status = AE_OK;
		struct semaphore sem = (struct semaphore )handle;
		long jiffies;
		int ret = 0;


		if (!sem \|\| (units < 1))
		return AE_BAD_PARAMETER;

		@@ -828,58 +826,14 @@ acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p\|%d\|%d]\n",
		handle, units, timeout));

		/*
		* This can be called during resume with interrupts off.
		* Like boot-time, we should be single threaded and will
		* always get the lock if we try -- timeout or not.
		* If this doesn't succeed, then we will oops courtesy of
		* might_sleep() in down().
		*/
		if (!down_trylock(sem))
		return AE_OK;

		switch (timeout) {
		/*
		* No Wait:
		* --------
		* A zero timeout value indicates that we shouldn't wait - just
		* acquire the semaphore if available otherwise return AE_TIME
		* (a.k.a. 'would block').
		*/
		case 0:
		if (down_trylock(sem))
		status = AE_TIME;
		break;

		/*
		* Wait Indefinitely:
		* ------------------
		*/
		case ACPI_WAIT_FOREVER:
		down(sem);
		break;

		/*
		* Wait w/ Timeout:
		* ----------------
		*/
		default:
		// TODO: A better timeout algorithm?
		{
		int i = 0;
		static const int quantum_ms = 1000 / HZ;

		ret = down_trylock(sem);
		for (i = timeout; (i > 0 && ret != 0); i -= quantum_ms) {
		schedule_timeout_interruptible(1);
		ret = down_trylock(sem);
		}
		if (timeout == ACPI_WAIT_FOREVER)
		jiffies = MAX_SCHEDULE_TIMEOUT;
		else
		jiffies = msecs_to_jiffies(timeout);

		if (ret != 0)
		ret = down_timeout(sem, jiffies);
		if (ret)
		status = AE_TIME;
		}
		break;
		}

		if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
		@@ -902,7 +856,6 @@ acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
		{
		struct semaphore sem = (struct semaphore )handle;


		if (!sem \|\| (units < 1))
		return AE_BAD_PARAMETER;

include/linux/semaphore.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,12 @@ extern int __must_check down_killable(struct semaphore *sem);
		*/
		extern int __must_check down_trylock(struct semaphore *sem);

		/*
		* As down(), except this function will return -ETIME if it fails to
		* acquire the semaphore within the specified number of jiffies.
		*/
		extern int __must_check down_timeout(struct semaphore *sem, long jiffies);

		/*
		* Release the semaphore. Unlike mutexes, up() may be called from any
		* context and even by tasks which have never called down().

kernel/semaphore.c

+35 −7

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@
		static noinline void __down(struct semaphore *sem);
		static noinline int __down_interruptible(struct semaphore *sem);
		static noinline int __down_killable(struct semaphore *sem);
		static noinline int __down_timeout(struct semaphore *sem, long jiffies);
		static noinline void __up(struct semaphore *sem);

		void down(struct semaphore *sem)
		@@ -104,6 +105,20 @@ int down_trylock(struct semaphore *sem)
		}
		EXPORT_SYMBOL(down_trylock);

		int down_timeout(struct semaphore *sem, long jiffies)
		{
		unsigned long flags;
		int result = 0;

		spin_lock_irqsave(&sem->lock, flags);
		if (unlikely(sem->count-- <= 0))
		result = __down_timeout(sem, jiffies);
		spin_unlock_irqrestore(&sem->lock, flags);

		return result;
		}
		EXPORT_SYMBOL(down_timeout);

		void up(struct semaphore *sem)
		{
		unsigned long flags;
		@@ -142,10 +157,12 @@ static noinline void __sched __up_down_common(struct semaphore *sem)
		}

		/*
		* Because this function is inlined, the 'state' parameter will be constant,
		* and thus optimised away by the compiler.
		* Because this function is inlined, the 'state' parameter will be
		* constant, and thus optimised away by the compiler. Likewise the
		* 'timeout' parameter for the cases without timeouts.
		*/
		static inline int __sched __down_common(struct semaphore *sem, long state)
		static inline int __sched __down_common(struct semaphore *sem, long state,
		long timeout)
		{
		int result = 0;
		struct task_struct *task = current;
		@@ -160,14 +177,20 @@ static inline int __sched __down_common(struct semaphore *sem, long state)
		goto interrupted;
		if (state == TASK_KILLABLE && fatal_signal_pending(task))
		goto interrupted;
		if (timeout <= 0)
		goto timed_out;
		__set_task_state(task, state);
		spin_unlock_irq(&sem->lock);
		schedule();
		timeout = schedule_timeout(timeout);
		spin_lock_irq(&sem->lock);
		if (waiter.up)
		goto woken;
		}

		timed_out:
		list_del(&waiter.list);
		result = -ETIME;
		goto woken;
		interrupted:
		list_del(&waiter.list);
		result = -EINTR;
		@@ -187,17 +210,22 @@ static inline int __sched __down_common(struct semaphore *sem, long state)

		static noinline void __sched __down(struct semaphore *sem)
		{
		__down_common(sem, TASK_UNINTERRUPTIBLE);
		__down_common(sem, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
		}

		static noinline int __sched __down_interruptible(struct semaphore *sem)
		{
		return __down_common(sem, TASK_INTERRUPTIBLE);
		return __down_common(sem, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
		}

		static noinline int __sched __down_killable(struct semaphore *sem)
		{
		return __down_common(sem, TASK_KILLABLE);
		return __down_common(sem, TASK_KILLABLE, MAX_SCHEDULE_TIMEOUT);
		}

		static noinline int __sched __down_timeout(struct semaphore *sem, long jiffies)
		{
		return __down_common(sem, TASK_UNINTERRUPTIBLE, jiffies);
		}

		static noinline void __sched __up(struct semaphore *sem)

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