1 files changed, 25 insertions, 0 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 3d525c6124f6..803b684676ff 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1338,6 +1338,26 @@ static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
 }
 
 /*
+ * ACPI offers an alternative platform interface model that removes
+ * ACPI hardware requirements for platforms that do not implement
+ * the PC Architecture.
+ *
+ * We initialize the Hardware-reduced ACPI model here:
+ */
+static void __init acpi_reduced_hw_init(void)
+{
+        if (acpi_gbl_reduced_hardware) {
+                /*
+                 * Override x86_init functions and bypass legacy pic
+                 * in Hardware-reduced ACPI mode
+                 */
+                x86_init.timers.timer_init      = x86_init_noop;
+                x86_init.irqs.pre_vector_init   = x86_init_noop;
+                legacy_pic                      = &null_legacy_pic;
+        }
+}
+
+/*
  * If your system is blacklisted here, but you find that acpi=force
  * works for you, please contact linux-acpi@vger.kernel.org
  */
@@ -1536,6 +1556,11 @@ int __init early_acpi_boot_init(void)
          */
         early_acpi_process_madt();
 
+        /*
+         * Hardware-reduced ACPI mode initialization:
+         */
+        acpi_reduced_hw_init();
+
         return 0;
 }