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@xxxxxx>
---
drivers/acpi/osl.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 3 +++
2 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index bd72129..fc6c5d2 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -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)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c227757..7774e6d 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -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
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
