Merge tag 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux...

[deliverable/linux.git] / arch / x86 / kernel / acpi / boot.c

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 3d525c6124f6c720e02d2761b283151be97cf6d7..803b684676ff3d0bcc6a17c530a457efcf485fca 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1337,6 +1337,26 @@ static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
        return 0;
 }
 
+/*
+ * 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;
 }