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Commit 5da2fd26 authored by Jiang Liu's avatar Jiang Liu Committed by Thomas Gleixner
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x86, irq, ACPI: Introduce a mutex to protect IOAPIC operations from hotplug 



We are going to support ACPI based IOAPIC hotplug, so introduce a mutex
to protect IOAPIC data structures from IOAPIC hotplug. We choose to
serialize in ACPI instead of in the IOAPIC core because:

1) currently we only plan to support ACPI based IOAPIC hotplug
2) it's much more cleaner and easier
3) It does't affect IOAPIC discovered by devicetree, SFI and mpparse.

Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Link: http://lkml.kernel.org/r/1414908273-7552-15-git-send-email-jiang.liu@linux.intel.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 35ef9c94

arch/x86/kernel/acpi/boot.c

+21 −0
Original line number Original line Diff line number Diff line
@@ -76,6 +76,19 @@ int acpi_fix_pin2_polarity __initdata; 
static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;

static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;

#endif

#endif





/*

 * Locks related to IOAPIC hotplug

 * Hotplug side:

 *	->device_hotplug_lock

 *		->acpi_ioapic_lock

 *			->ioapic_lock

 * Interrupt mapping side:

 *	->acpi_ioapic_lock

 *		->ioapic_mutex

 *			->ioapic_lock

 */

static DEFINE_MUTEX(acpi_ioapic_lock);



/* --------------------------------------------------------------------------

/* --------------------------------------------------------------------------

                              Boot-time Configuration

                              Boot-time Configuration

   -------------------------------------------------------------------------- */

   -------------------------------------------------------------------------- */
@@ -609,8 +622,10 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp) 
	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {

	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {

		*irqp = gsi;

		*irqp = gsi;

	} else {

	} else {

		mutex_lock(&acpi_ioapic_lock);

		irq = mp_map_gsi_to_irq(gsi,

		irq = mp_map_gsi_to_irq(gsi,

					IOAPIC_MAP_ALLOC | IOAPIC_MAP_CHECK);

					IOAPIC_MAP_ALLOC | IOAPIC_MAP_CHECK);

		mutex_unlock(&acpi_ioapic_lock);

		if (irq < 0)

		if (irq < 0)

			return -1;

			return -1;

		*irqp = irq;

		*irqp = irq;
@@ -650,7 +665,9 @@ static int acpi_register_gsi_ioapic(struct device *dev, u32 gsi, 
	int irq = gsi;

	int irq = gsi;





#ifdef CONFIG_X86_IO_APIC

#ifdef CONFIG_X86_IO_APIC

	mutex_lock(&acpi_ioapic_lock);

	irq = mp_register_gsi(dev, gsi, trigger, polarity);

	irq = mp_register_gsi(dev, gsi, trigger, polarity);

	mutex_unlock(&acpi_ioapic_lock);

#endif

#endif





	return irq;

	return irq;
@@ -659,7 +676,9 @@ static int acpi_register_gsi_ioapic(struct device *dev, u32 gsi, 
static void acpi_unregister_gsi_ioapic(u32 gsi)

static void acpi_unregister_gsi_ioapic(u32 gsi)

{

{

#ifdef CONFIG_X86_IO_APIC

#ifdef CONFIG_X86_IO_APIC

	mutex_lock(&acpi_ioapic_lock);

	mp_unregister_gsi(gsi);

	mp_unregister_gsi(gsi);

	mutex_unlock(&acpi_ioapic_lock);

#endif

#endif

}

}
@@ -1187,7 +1206,9 @@ static void __init acpi_process_madt(void) 
			/*

			/*

			 * Parse MADT IO-APIC entries

			 * Parse MADT IO-APIC entries

			 */

			 */

			mutex_lock(&acpi_ioapic_lock);

			error = acpi_parse_madt_ioapic_entries();

			error = acpi_parse_madt_ioapic_entries();

			mutex_unlock(&acpi_ioapic_lock);

			if (!error) {

			if (!error) {

				acpi_set_irq_model_ioapic();

				acpi_set_irq_model_ioapic();