ACPI 5.0: Implement hardware-reduced option

If HW-reduced flag is set in the FADT, do not attempt to access
or initialize any ACPI hardware, including SCI and global lock.
No FACS will be present.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/evglock.c b/drivers/acpi/acpica/evglock.c
index 56a562a1e5d7..af1e71af1b64 100644
--- a/drivers/acpi/acpica/evglock.c
+++ b/drivers/acpi/acpica/evglock.c
@@ -70,6 +70,12 @@ acpi_status acpi_ev_init_global_lock_handler(void)
 
         ACPI_FUNCTION_TRACE(ev_init_global_lock_handler);
 
+        /* If Hardware Reduced flag is set, there is no global lock */
+
+        if (acpi_gbl_reduced_hardware) {
+                return_ACPI_STATUS(AE_OK);
+        }
+
         /* Attempt installation of the global lock handler */
 
         status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL,