[PATCH 2/3] ACPICA: Add interface for getting latest OS version requested via _OSI

[Matthew Garrett <matthew.garrett@nebula.com>]

Drivers may need to make policy decisions based on the OS that the firmware
believes it's interacting with. ACPI firmware will make a series of _OSI
calls, starting from the oldest OS version they support and ending with the
most recent. Add a function to return the last successful call so that
drivers know what the firmware's expecting.

Based on a patch by Seth Forshee <seth.forshee@canonical.com>

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
---
 drivers/acpi/acpica/aclocal.h | 13 -------------
 drivers/acpi/acpica/utxface.c | 19 +++++++++++++++++++
 include/acpi/acpixf.h         | 22 ++++++++++++++++++++++
 3 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index d5bfbd3..8a2f532 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -948,19 +948,6 @@ struct acpi_bit_register_info {
 
 /* Structs and definitions for _OSI support and I/O port validation */
 
-#define ACPI_OSI_WIN_2000               0x01
-#define ACPI_OSI_WIN_XP                 0x02
-#define ACPI_OSI_WIN_XP_SP1             0x03
-#define ACPI_OSI_WINSRV_2003            0x04
-#define ACPI_OSI_WIN_XP_SP2             0x05
-#define ACPI_OSI_WINSRV_2003_SP1        0x06
-#define ACPI_OSI_WIN_VISTA              0x07
-#define ACPI_OSI_WINSRV_2008            0x08
-#define ACPI_OSI_WIN_VISTA_SP1          0x09
-#define ACPI_OSI_WIN_VISTA_SP2          0x0A
-#define ACPI_OSI_WIN_7                  0x0B
-#define ACPI_OSI_WIN_8                  0x0C
-
 #define ACPI_ALWAYS_ILLEGAL             0x00
 
 struct acpi_interface_info {
diff --git a/drivers/acpi/acpica/utxface.c b/drivers/acpi/acpica/utxface.c
index 6505774..c1638c3 100644
--- a/drivers/acpi/acpica/utxface.c
+++ b/drivers/acpi/acpica/utxface.c
@@ -389,6 +389,25 @@ ACPI_EXPORT_SYMBOL(acpi_install_interface_handler)
 
 /*****************************************************************************
  *
+ * FUNCTION:    acpi_osi_version
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Last OS version requested via _OSI
+ *
+ * DESCRIPTION: Returns the argument to the most recent _OSI query performed
+ *		by the firmware
+ *
+ ****************************************************************************/
+u8 acpi_osi_version(void)
+{
+	return acpi_gbl_osi_data;
+}
+
+ACPI_EXPORT_SYMBOL(acpi_osi_version)
+
+/*****************************************************************************
+ *
  * FUNCTION:    acpi_check_address_range
  *
  * PARAMETERS:  space_id            - Address space ID
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 454881e..41d3ac1 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -82,6 +82,22 @@ extern u8 acpi_gbl_truncate_io_addresses;
 extern u8 acpi_gbl_disable_auto_repair;
 
 /*
+ * Values returned by acpi_osi_version()
+ */
+#define ACPI_OSI_WIN_2000               0x01
+#define ACPI_OSI_WIN_XP                 0x02
+#define ACPI_OSI_WIN_XP_SP1             0x03
+#define ACPI_OSI_WINSRV_2003            0x04
+#define ACPI_OSI_WIN_XP_SP2             0x05
+#define ACPI_OSI_WINSRV_2003_SP1        0x06
+#define ACPI_OSI_WIN_VISTA              0x07
+#define ACPI_OSI_WINSRV_2008            0x08
+#define ACPI_OSI_WIN_VISTA_SP1          0x09
+#define ACPI_OSI_WIN_VISTA_SP2          0x0A
+#define ACPI_OSI_WIN_7                  0x0B
+#define ACPI_OSI_WIN_8                  0x0C
+
+/*
  * Hardware-reduced prototypes. All interfaces that use these macros will
  * be configured out of the ACPICA build if the ACPI_REDUCED_HARDWARE flag
  * is set to TRUE.
@@ -307,6 +323,12 @@ acpi_status acpi_install_notify_handler(acpi_handle device, u32 handler_type,
 					acpi_notify_handler handler,
 					void *context);
 
+#ifdef CONFIG_ACPI
+u8 acpi_osi_version(void);
+#else
+static inline u8 acpi_osi_version(void) { return 0; }
+#endif
+
 acpi_status
 acpi_remove_notify_handler(acpi_handle device,
 			   u32 handler_type, acpi_notify_handler handler);
-- 
1.8.2.1