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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: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Myron Stowe 2010-10-21 14:23:59 -06:00 committed by Len Brown
parent 620242ae8c
commit 2971852123
2 changed files with 41 additions and 0 deletions
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38
drivers/acpi/osl.c
View File

@ -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)

3
include/linux/acpi.h
View File

@ -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