1 files changed, 59 insertions, 8 deletions

diff --git a/drivers/acpi/main.c b/drivers/acpi/main.c
index d8242772de92..7e3c609cbef2 100644
--- a/drivers/acpi/main.c
+++ b/drivers/acpi/main.c
@@ -101,6 +101,19 @@ void __init acpi_old_suspend_ordering(void)
  * cases.
  */
 static bool set_sci_en_on_resume;
+/*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * and to restore them during the subsequent resume.  However, it is not certain
+ * if this mechanism is going to work on all machines, so we allow the user to
+ * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
+ * option.
+ */
+static bool s4_no_nvs;
+
+void __init acpi_s4_no_nvs(void)
+{
+        s4_no_nvs = true;
+}
 
 /**
  *      acpi_pm_disable_gpes - Disable the GPEs.
@@ -394,9 +407,25 @@ void __init acpi_no_s4_hw_signature(void)
 
 static int acpi_hibernation_begin(void)
 {
-        acpi_target_sleep_state = ACPI_STATE_S4;
-        acpi_sleep_tts_switch(acpi_target_sleep_state);
-        return 0;
+        int error;
+
+        error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
+        if (!error) {
+                acpi_target_sleep_state = ACPI_STATE_S4;
+                acpi_sleep_tts_switch(acpi_target_sleep_state);
+        }
+
+        return error;
+}
+
+static int acpi_hibernation_pre_snapshot(void)
+{
+        int error = acpi_pm_prepare();
+
+        if (!error)
+                hibernate_nvs_save();
+
+        return error;
 }
 
 static int acpi_hibernation_enter(void)
@@ -417,6 +446,12 @@ static int acpi_hibernation_enter(void)
         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 }
 
+static void acpi_hibernation_finish(void)
+{
+        hibernate_nvs_free();
+        acpi_pm_finish();
+}
+
 static void acpi_hibernation_leave(void)
 {
         /*
@@ -432,6 +467,8 @@ static void acpi_hibernation_leave(void)
                         "cannot resume!\n");
                 panic("ACPI S4 hardware signature mismatch");
         }
+        /* Restore the NVS memory area */
+        hibernate_nvs_restore();
 }
 
 static void acpi_pm_enable_gpes(void)
@@ -442,8 +479,8 @@ static void acpi_pm_enable_gpes(void)
 static struct platform_hibernation_ops acpi_hibernation_ops = {
         .begin = acpi_hibernation_begin,
         .end = acpi_pm_end,
-        .pre_snapshot = acpi_pm_prepare,
-        .finish = acpi_pm_finish,
+        .pre_snapshot = acpi_hibernation_pre_snapshot,
+        .finish = acpi_hibernation_finish,
         .prepare = acpi_pm_prepare,
         .enter = acpi_hibernation_enter,
         .leave = acpi_hibernation_leave,
@@ -469,8 +506,22 @@ static int acpi_hibernation_begin_old(void)
 
         error = acpi_sleep_prepare(ACPI_STATE_S4);
 
+        if (!error) {
+                if (!s4_no_nvs)
+                        error = hibernate_nvs_alloc();
+                if (!error)
+                        acpi_target_sleep_state = ACPI_STATE_S4;
+        }
+        return error;
+}
+
+static int acpi_hibernation_pre_snapshot_old(void)
+{
+        int error = acpi_pm_disable_gpes();
+
         if (!error)
-                acpi_target_sleep_state = ACPI_STATE_S4;
+                hibernate_nvs_save();
+
         return error;
 }
 
@@ -481,8 +532,8 @@ static int acpi_hibernation_begin_old(void)
 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
         .begin = acpi_hibernation_begin_old,
         .end = acpi_pm_end,
-        .pre_snapshot = acpi_pm_disable_gpes,
-        .finish = acpi_pm_finish,
+        .pre_snapshot = acpi_hibernation_pre_snapshot_old,
+        .finish = acpi_hibernation_finish,
         .prepare = acpi_pm_disable_gpes,
         .enter = acpi_hibernation_enter,
         .leave = acpi_hibernation_leave,