Commit d362edaf authored by Myron Stowe's avatar Myron Stowe Committed by Len Brown
Browse files

ACPI: Pre-map 'system event' related register blocks 

During ACPI initialization, pre-map fixed hardware registers that are
accessed during ACPI's 'system event' related IRQ handing.

ACPI's 'system event' handing accesses specific fixed hardware
registers; namely PM1a event, PM1b event, GPE0, and GPE1 register
blocks which are declared within the FADT.  If these registers are
backed by MMIO, as opposed to I/O port space, accessing them within
interrupt context will cause a panic as acpi_os_read_memory()
depends on ioremap() in such cases - BZ 18012.

By utilizing the functionality provided in the previous two patches -
ACPI: Maintain a list of ACPI memory mapped I/O remappings, and, ACPI:
Add interfaces for ioremapping/iounmapping ACPI registers - accesses
to ACPI MMIO areas will now be safe from within interrupt contexts (IRQ
and/or NMI) provided the area was pre-mapped.  This solves BZ 18012.

ACPI "System Event" reference(s):
  ACPI Specification, Revision 4.0, Section 3 "ACPI Overview",
  3.8 "System Events", 5.6 "ACPI Event Programming Model".

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=18012



Reported-by: default avatar <bjorn.helgaas@hp.com>
Signed-off-by: default avatarMyron Stowe <myron.stowe@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 29718521

drivers/acpi/osl.c

+40 −31
Original line number Diff line number Diff line
@@ -199,36 +199,6 @@ static int __init acpi_reserve_resources(void) 
}

device_initcall(acpi_reserve_resources);



acpi_status __init acpi_os_initialize(void)

{

	return AE_OK;

}



acpi_status acpi_os_initialize1(void)

{

	kacpid_wq = create_workqueue("kacpid");

	kacpi_notify_wq = create_workqueue("kacpi_notify");

	kacpi_hotplug_wq = create_workqueue("kacpi_hotplug");

	BUG_ON(!kacpid_wq);

	BUG_ON(!kacpi_notify_wq);

	BUG_ON(!kacpi_hotplug_wq);

	return AE_OK;

}



acpi_status acpi_os_terminate(void)

{

	if (acpi_irq_handler) {

		acpi_os_remove_interrupt_handler(acpi_irq_irq,

						 acpi_irq_handler);

	}



	destroy_workqueue(kacpid_wq);

	destroy_workqueue(kacpi_notify_wq);

	destroy_workqueue(kacpi_hotplug_wq);



	return AE_OK;

}



void acpi_os_printf(const char *fmt, ...)

{

	va_list args;
@@ -1598,5 +1568,44 @@ acpi_os_validate_address ( 
	}

	return AE_OK;

}



#endif



acpi_status __init acpi_os_initialize(void)

{

	acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block);

	acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block);

	acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block);

	acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block);



	return AE_OK;

}



acpi_status acpi_os_initialize1(void)

{

	kacpid_wq = create_workqueue("kacpid");

	kacpi_notify_wq = create_workqueue("kacpi_notify");

	kacpi_hotplug_wq = create_workqueue("kacpi_hotplug");

	BUG_ON(!kacpid_wq);

	BUG_ON(!kacpi_notify_wq);

	BUG_ON(!kacpi_hotplug_wq);

	return AE_OK;

}



acpi_status acpi_os_terminate(void)

{

	if (acpi_irq_handler) {

		acpi_os_remove_interrupt_handler(acpi_irq_irq,

						 acpi_irq_handler);

	}



	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block);

	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block);

	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block);

	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block);



	destroy_workqueue(kacpid_wq);

	destroy_workqueue(kacpi_notify_wq);

	destroy_workqueue(kacpi_hotplug_wq);



	return AE_OK;

}

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