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path: root/drivers/acpi/osl.c
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Diffstat (limited to 'drivers/acpi/osl.c')
-rw-r--r--drivers/acpi/osl.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 7ca41bf023c9..8df9abfa947b 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -45,6 +45,8 @@
#include <linux/uaccess.h>
#include <linux/io-64-nonatomic-lo-hi.h>
+#include "acpica/accommon.h"
+#include "acpica/acnamesp.h"
#include "internal.h"
#define _COMPONENT ACPI_OS_SERVICES
@@ -1490,6 +1492,76 @@ int acpi_check_region(resource_size_t start, resource_size_t n,
}
EXPORT_SYMBOL(acpi_check_region);
+static acpi_status acpi_deactivate_mem_region(acpi_handle handle, u32 level,
+ void *_res, void **return_value)
+{
+ struct acpi_mem_space_context **mem_ctx;
+ union acpi_operand_object *handler_obj;
+ union acpi_operand_object *region_obj2;
+ union acpi_operand_object *region_obj;
+ struct resource *res = _res;
+ acpi_status status;
+
+ region_obj = acpi_ns_get_attached_object(handle);
+ if (!region_obj)
+ return AE_OK;
+
+ handler_obj = region_obj->region.handler;
+ if (!handler_obj)
+ return AE_OK;
+
+ if (region_obj->region.space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
+ return AE_OK;
+
+ if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE))
+ return AE_OK;
+
+ region_obj2 = acpi_ns_get_secondary_object(region_obj);
+ if (!region_obj2)
+ return AE_OK;
+
+ mem_ctx = (void *)&region_obj2->extra.region_context;
+
+ if (!(mem_ctx[0]->address >= res->start &&
+ mem_ctx[0]->address < res->end))
+ return AE_OK;
+
+ status = handler_obj->address_space.setup(region_obj,
+ ACPI_REGION_DEACTIVATE,
+ NULL, (void **)mem_ctx);
+ if (ACPI_SUCCESS(status))
+ region_obj->region.flags &= ~(AOPOBJ_SETUP_COMPLETE);
+
+ return status;
+}
+
+/**
+ * acpi_release_memory - Release any mappings done to a memory region
+ * @handle: Handle to namespace node
+ * @res: Memory resource
+ * @level: A level that terminates the search
+ *
+ * Walks through @handle and unmaps all SystemMemory Operation Regions that
+ * overlap with @res and that have already been activated (mapped).
+ *
+ * This is a helper that allows drivers to place special requirements on memory
+ * region that may overlap with operation regions, primarily allowing them to
+ * safely map the region as non-cached memory.
+ *
+ * The unmapped Operation Regions will be automatically remapped next time they
+ * are called, so the drivers do not need to do anything else.
+ */
+acpi_status acpi_release_memory(acpi_handle handle, struct resource *res,
+ u32 level)
+{
+ if (!(res->flags & IORESOURCE_MEM))
+ return AE_TYPE;
+
+ return acpi_walk_namespace(ACPI_TYPE_REGION, handle, level,
+ acpi_deactivate_mem_region, NULL, res, NULL);
+}
+EXPORT_SYMBOL_GPL(acpi_release_memory);
+
/*
* Let drivers know whether the resource checks are effective
*/