[PATCH v4 5/5] ACPI: do not map/unmap memory regions for FADT entries in reduced HW mode

[al.stone at linaro.org]

From: Al Stone <al.stone at linaro.org>

Several of the FADT fields are normally kept in specific memory
regions.  Since these fields are to be ignored in hardware reduced
ACPI mode, do not map those addresses when in that mode, and of
course do not release the mappings that have not been made.

The function acpi_os_initialize() could become a stub in the header
file but is left here in case it can be of further use.

Signed-off-by: Al Stone <al.stone at linaro.org>
---
 drivers/acpi/osl.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index c946a3a..7822821 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1778,10 +1778,12 @@ __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);
 
 acpi_status __init acpi_os_initialize(void)
 {
-	acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block);
-	acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
-	acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block);
-	acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block);
+	if (!acpi_gbl_reduced_hardware) {
+		acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block);
+		acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
+		acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe0_block);
+		acpi_os_map_generic_address(&acpi_gbl_FADT.xgpe1_block);
+	}
 
 	return AE_OK;
 }
@@ -1806,10 +1808,12 @@ acpi_status acpi_os_terminate(void)
 						 acpi_irq_handler);
 	}
 
-	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block);
-	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block);
-	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
-	acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block);
+	if (!acpi_gbl_reduced_hardware) {
+		acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe1_block);
+		acpi_os_unmap_generic_address(&acpi_gbl_FADT.xgpe0_block);
+		acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1b_event_block);
+		acpi_os_unmap_generic_address(&acpi_gbl_FADT.xpm1a_event_block);
+	}
 
 	destroy_workqueue(kacpid_wq);
 	destroy_workqueue(kacpi_notify_wq);
-- 
1.8.3.1