Commit 29718521 authored by Myron Stowe's avatar Myron Stowe Committed by Len Brown
Browse files

ACPI: Add interfaces for ioremapping/iounmapping ACPI registers 



Add remapping and unmapping interfaces for ACPI registers that are
backed by memory mapped I/O (MMIO).  These interfaces, along with
the MMIO remapping list, enable accesses of such registers from within
interrupt context.

ACPI Generic Address Structure (GAS) reference (ACPI's fixed/generic
hardware registers use the GAS format):
  ACPI Specification, Revision 4.0, Section 5.2.3.1, "Generic Address
  Structure".

Signed-off-by: default avatarMyron Stowe <myron.stowe@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 620242ae

drivers/acpi/osl.c

+38 −0
Original line number Diff line number Diff line
@@ -372,6 +372,44 @@ void __init early_acpi_os_unmap_memory(void __iomem *virt, acpi_size size) 
		__acpi_unmap_table(virt, size);

}



int acpi_os_map_generic_address(struct acpi_generic_address *addr)

{

	void __iomem *virt;



	if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)

		return 0;



	if (!addr->address || !addr->bit_width)

		return -EINVAL;



	virt = acpi_os_map_memory(addr->address, addr->bit_width / 8);

	if (!virt)

		return -EIO;



	return 0;

}

EXPORT_SYMBOL_GPL(acpi_os_map_generic_address);



void acpi_os_unmap_generic_address(struct acpi_generic_address *addr)

{

	void __iomem *virt;

	unsigned long flags;

	acpi_size size = addr->bit_width / 8;



	if (addr->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)

		return;



	if (!addr->address || !addr->bit_width)

		return;



	spin_lock_irqsave(&acpi_ioremap_lock, flags);

	virt = acpi_map_vaddr_lookup(addr->address, size);

	spin_unlock_irqrestore(&acpi_ioremap_lock, flags);



	acpi_os_unmap_memory(virt, size);

}

EXPORT_SYMBOL_GPL(acpi_os_unmap_generic_address);



#ifdef ACPI_FUTURE_USAGE

acpi_status

acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)

include/linux/acpi.h

+3 −0
Original line number Diff line number Diff line
@@ -308,6 +308,9 @@ extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, 
					     u32 *mask, u32 req);

extern void acpi_early_init(void);



int acpi_os_map_generic_address(struct acpi_generic_address *addr);

void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);



#else	/* !CONFIG_ACPI */



#define acpi_disabled 1

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