[PATCH 7/8] ACPI: Introduce acpi_os_get_iomem()

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rjw@sisk.pl>

Introduce function acpi_os_get_iomem() that may be used by its callers
to get a reference to an ACPI iomap.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/acpi/osl.c      |   16 ++++++++++++++++
 include/linux/acpi_io.h |    2 ++
 2 files changed, 18 insertions(+)

Index: linux-2.6/drivers/acpi/osl.c
===================================================================
--- linux-2.6.orig/drivers/acpi/osl.c
+++ linux-2.6/drivers/acpi/osl.c
@@ -285,6 +285,22 @@ acpi_map_vaddr_lookup(acpi_physical_addr
 	return NULL;
 }
 
+void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size)
+{
+	struct acpi_ioremap *map;
+	void __iomem *virt = NULL;
+
+	mutex_lock(&acpi_ioremap_lock);
+	map = acpi_map_lookup(phys, size);
+	if (map) {
+		virt = map->virt + (phys - map->phys);
+		map->refcount++;
+	}
+	mutex_unlock(&acpi_ioremap_lock);
+	return virt;
+}
+EXPORT_SYMBOL_GPL(acpi_os_get_iomem);
+
 /* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */
 static struct acpi_ioremap *
 acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
Index: linux-2.6/include/linux/acpi_io.h
===================================================================
--- linux-2.6.orig/include/linux/acpi_io.h
+++ linux-2.6/include/linux/acpi_io.h
@@ -10,4 +10,6 @@ static inline void __iomem *acpi_os_iore
        return ioremap_cache(phys, size);
 }
 
+void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
+
 #endif