pci_link.c

来自「linux 内核源代码」· C语言 代码 · 共 956 行 · 第 1/2 页

int __init acpi_irq_penalty_init(void)
{
	struct list_head *node = NULL;
	struct acpi_pci_link *link = NULL;
	int i = 0;


	/*
	 * Update penalties to facilitate IRQ balancing.
	 */
	list_for_each(node, &acpi_link.entries) {

		link = list_entry(node, struct acpi_pci_link, node);
		if (!link) {
			printk(KERN_ERR PREFIX "Invalid link context\n");
			continue;
		}

		/*
		 * reflect the possible and active irqs in the penalty table --
		 * useful for breaking ties.
		 */
		if (link->irq.possible_count) {
			int penalty =
			    PIRQ_PENALTY_PCI_POSSIBLE /
			    link->irq.possible_count;

			for (i = 0; i < link->irq.possible_count; i++) {
				if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
					acpi_irq_penalty[link->irq.
							 possible[i]] +=
					    penalty;
			}

		} else if (link->irq.active) {
			acpi_irq_penalty[link->irq.active] +=
			    PIRQ_PENALTY_PCI_POSSIBLE;
		}
	}
	/* Add a penalty for the SCI */
	acpi_irq_penalty[acpi_gbl_FADT.sci_interrupt] += PIRQ_PENALTY_PCI_USING;

	return 0;
}

static int acpi_irq_balance;	/* 0: static, 1: balance */

static int acpi_pci_link_allocate(struct acpi_pci_link *link)
{
	int irq;
	int i;


	if (link->irq.initialized) {
		if (link->refcnt == 0)
			/* This means the link is disabled but initialized */
			acpi_pci_link_set(link, link->irq.active);
		return 0;
	}

	/*
	 * search for active IRQ in list of possible IRQs.
	 */
	for (i = 0; i < link->irq.possible_count; ++i) {
		if (link->irq.active == link->irq.possible[i])
			break;
	}
	/*
	 * forget active IRQ that is not in possible list
	 */
	if (i == link->irq.possible_count) {
		if (acpi_strict)
			printk(KERN_WARNING PREFIX "_CRS %d not found"
				      " in _PRS\n", link->irq.active);
		link->irq.active = 0;
	}

	/*
	 * if active found, use it; else pick entry from end of possible list.
	 */
	if (link->irq.active) {
		irq = link->irq.active;
	} else {
		irq = link->irq.possible[link->irq.possible_count - 1];
	}

	if (acpi_irq_balance || !link->irq.active) {
		/*
		 * Select the best IRQ.  This is done in reverse to promote
		 * the use of IRQs 9, 10, 11, and >15.
		 */
		for (i = (link->irq.possible_count - 1); i >= 0; i--) {
			if (acpi_irq_penalty[irq] >
			    acpi_irq_penalty[link->irq.possible[i]])
				irq = link->irq.possible[i];
		}
	}

	/* Attempt to enable the link device at this IRQ. */
	if (acpi_pci_link_set(link, irq)) {
		printk(KERN_ERR PREFIX "Unable to set IRQ for %s [%s]. "
			    "Try pci=noacpi or acpi=off\n",
			    acpi_device_name(link->device),
			    acpi_device_bid(link->device));
		return -ENODEV;
	} else {
		acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
		printk(PREFIX "%s [%s] enabled at IRQ %d\n",
		       acpi_device_name(link->device),
		       acpi_device_bid(link->device), link->irq.active);
	}

	link->irq.initialized = 1;

	return 0;
}

/*
 * acpi_pci_link_allocate_irq
 * success: return IRQ >= 0
 * failure: return -1
 */

int
acpi_pci_link_allocate_irq(acpi_handle handle,
			   int index,
			   int *triggering, int *polarity, char **name)
{
	int result = 0;
	struct acpi_device *device = NULL;
	struct acpi_pci_link *link = NULL;


	result = acpi_bus_get_device(handle, &device);
	if (result) {
		printk(KERN_ERR PREFIX "Invalid link device\n");
		return -1;
	}

	link = acpi_driver_data(device);
	if (!link) {
		printk(KERN_ERR PREFIX "Invalid link context\n");
		return -1;
	}

	/* TBD: Support multiple index (IRQ) entries per Link Device */
	if (index) {
		printk(KERN_ERR PREFIX "Invalid index %d\n", index);
		return -1;
	}

	mutex_lock(&acpi_link_lock);
	if (acpi_pci_link_allocate(link)) {
		mutex_unlock(&acpi_link_lock);
		return -1;
	}

	if (!link->irq.active) {
		mutex_unlock(&acpi_link_lock);
		printk(KERN_ERR PREFIX "Link active IRQ is 0!\n");
		return -1;
	}
	link->refcnt++;
	mutex_unlock(&acpi_link_lock);

	if (triggering)
		*triggering = link->irq.triggering;
	if (polarity)
		*polarity = link->irq.polarity;
	if (name)
		*name = acpi_device_bid(link->device);
	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Link %s is referenced\n",
			  acpi_device_bid(link->device)));
	return (link->irq.active);
}

/*
 * We don't change link's irq information here.  After it is reenabled, we
 * continue use the info
 */
int acpi_pci_link_free_irq(acpi_handle handle)
{
	struct acpi_device *device = NULL;
	struct acpi_pci_link *link = NULL;
	acpi_status result;


	result = acpi_bus_get_device(handle, &device);
	if (result) {
		printk(KERN_ERR PREFIX "Invalid link device\n");
		return -1;
	}

	link = acpi_driver_data(device);
	if (!link) {
		printk(KERN_ERR PREFIX "Invalid link context\n");
		return -1;
	}

	mutex_lock(&acpi_link_lock);
	if (!link->irq.initialized) {
		mutex_unlock(&acpi_link_lock);
		printk(KERN_ERR PREFIX "Link isn't initialized\n");
		return -1;
	}
#ifdef	FUTURE_USE
	/*
	 * The Link reference count allows us to _DISable an unused link
	 * and suspend time, and set it again  on resume.
	 * However, 2.6.12 still has irq_router.resume
	 * which blindly restores the link state.
	 * So we disable the reference count method
	 * to prevent duplicate acpi_pci_link_set()
	 * which would harm some systems
	 */
	link->refcnt--;
#endif
	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Link %s is dereferenced\n",
			  acpi_device_bid(link->device)));

	if (link->refcnt == 0) {
		acpi_ut_evaluate_object(link->device->handle, "_DIS", 0, NULL);
	}
	mutex_unlock(&acpi_link_lock);
	return (link->irq.active);
}

/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

static int acpi_pci_link_add(struct acpi_device *device)
{
	int result = 0;
	struct acpi_pci_link *link = NULL;
	int i = 0;
	int found = 0;


	if (!device)
		return -EINVAL;

	link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
	if (!link)
		return -ENOMEM;

	link->device = device;
	strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
	acpi_driver_data(device) = link;

	mutex_lock(&acpi_link_lock);
	result = acpi_pci_link_get_possible(link);
	if (result)
		goto end;

	/* query and set link->irq.active */
	acpi_pci_link_get_current(link);

	printk(KERN_INFO PREFIX "%s [%s] (IRQs", acpi_device_name(device),
	       acpi_device_bid(device));
	for (i = 0; i < link->irq.possible_count; i++) {
		if (link->irq.active == link->irq.possible[i]) {
			printk(" *%d", link->irq.possible[i]);
			found = 1;
		} else
			printk(" %d", link->irq.possible[i]);
	}

	printk(")");

	if (!found)
		printk(" *%d", link->irq.active);

	if (!link->device->status.enabled)
		printk(", disabled.");

	printk("\n");

	/* TBD: Acquire/release lock */
	list_add_tail(&link->node, &acpi_link.entries);
	acpi_link.count++;

      end:
	/* disable all links -- to be activated on use */
	acpi_ut_evaluate_object(device->handle, "_DIS", 0, NULL);
	mutex_unlock(&acpi_link_lock);

	if (result)
		kfree(link);

	return result;
}

static int acpi_pci_link_resume(struct acpi_pci_link *link)
{

	if (link->refcnt && link->irq.active && link->irq.initialized)
		return (acpi_pci_link_set(link, link->irq.active));
	else
		return 0;
}

static int irqrouter_resume(struct sys_device *dev)
{
	struct list_head *node = NULL;
	struct acpi_pci_link *link = NULL;


	/* Make sure SCI is enabled again (Apple firmware bug?) */
	acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);

	list_for_each(node, &acpi_link.entries) {
		link = list_entry(node, struct acpi_pci_link, node);
		if (!link) {
			printk(KERN_ERR PREFIX "Invalid link context\n");
			continue;
		}
		acpi_pci_link_resume(link);
	}
	return 0;
}

static int acpi_pci_link_remove(struct acpi_device *device, int type)
{
	struct acpi_pci_link *link = NULL;


	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	link = acpi_driver_data(device);

	mutex_lock(&acpi_link_lock);
	list_del(&link->node);
	mutex_unlock(&acpi_link_lock);

	kfree(link);

	return 0;
}

/*
 * modify acpi_irq_penalty[] from cmdline
 */
static int __init acpi_irq_penalty_update(char *str, int used)
{
	int i;

	for (i = 0; i < 16; i++) {
		int retval;
		int irq;

		retval = get_option(&str, &irq);

		if (!retval)
			break;	/* no number found */

		if (irq < 0)
			continue;

		if (irq >= ACPI_MAX_IRQS)
			continue;

		if (used)
			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
		else
			acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;

		if (retval != 2)	/* no next number */
			break;
	}
	return 1;
}

/*
 * We'd like PNP to call this routine for the
 * single ISA_USED value for each legacy device.
 * But instead it calls us with each POSSIBLE setting.
 * There is no ISA_POSSIBLE weight, so we simply use
 * the (small) PCI_USING penalty.
 */
void acpi_penalize_isa_irq(int irq, int active)
{
	if (active)
		acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
	else
		acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
}

/*
 * Over-ride default table to reserve additional IRQs for use by ISA
 * e.g. acpi_irq_isa=5
 * Useful for telling ACPI how not to interfere with your ISA sound card.
 */
static int __init acpi_irq_isa(char *str)
{
	return acpi_irq_penalty_update(str, 1);
}

__setup("acpi_irq_isa=", acpi_irq_isa);

/*
 * Over-ride default table to free additional IRQs for use by PCI
 * e.g. acpi_irq_pci=7,15
 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 */
static int __init acpi_irq_pci(char *str)
{
	return acpi_irq_penalty_update(str, 0);
}

__setup("acpi_irq_pci=", acpi_irq_pci);

static int __init acpi_irq_nobalance_set(char *str)
{
	acpi_irq_balance = 0;
	return 1;
}

__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);

int __init acpi_irq_balance_set(char *str)
{
	acpi_irq_balance = 1;
	return 1;
}

__setup("acpi_irq_balance", acpi_irq_balance_set);

/* FIXME: we will remove this interface after all drivers call pci_disable_device */
static struct sysdev_class irqrouter_sysdev_class = {
	set_kset_name("irqrouter"),
	.resume = irqrouter_resume,
};

static struct sys_device device_irqrouter = {
	.id = 0,
	.cls = &irqrouter_sysdev_class,
};

static int __init irqrouter_init_sysfs(void)
{
	int error;


	if (acpi_disabled || acpi_noirq)
		return 0;

	error = sysdev_class_register(&irqrouter_sysdev_class);
	if (!error)
		error = sysdev_register(&device_irqrouter);

	return error;
}

device_initcall(irqrouter_init_sysfs);

static int __init acpi_pci_link_init(void)
{

	if (acpi_noirq)
		return 0;

	acpi_link.count = 0;
	INIT_LIST_HEAD(&acpi_link.entries);

	if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
		return -ENODEV;

	return 0;
}

subsys_initcall(acpi_pci_link_init);