diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index c0538f82c9a220cfafbb20d7d954eff6eff5053e..57ef2094af93ede71e6ad6283fd699160d21de5d 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -132,6 +132,7 @@ void native_play_dead(void);
 void play_dead_common(void);
 void wbinvd_on_cpu(int cpu);
 int wbinvd_on_all_cpus(void);
+bool wakeup_cpu0(void);
 
 void native_smp_send_reschedule(int cpu);
 void native_send_call_func_ipi(const struct cpumask *mask);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 7bdc0239a9435a131cfe8dda7b8d28ed97956696..14cd3186dc77dc7a929a47026bfa8c3152f89308 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1554,10 +1554,18 @@ void __init acpi_boot_table_init(void)
 	/*
 	 * Initialize the ACPI boot-time table parser.
 	 */
-	if (acpi_table_init()) {
+	if (acpi_locate_initial_tables())
 		disable_acpi();
-		return;
-	}
+	else
+		acpi_reserve_initial_tables();
+}
+
+int __init early_acpi_boot_init(void)
+{
+	if (acpi_disabled)
+		return 1;
+
+	acpi_table_init_complete();
 
 	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
 
@@ -1570,18 +1578,9 @@ void __init acpi_boot_table_init(void)
 		} else {
 			printk(KERN_WARNING PREFIX "Disabling ACPI support\n");
 			disable_acpi();
-			return;
+			return 1;
 		}
 	}
-}
-
-int __init early_acpi_boot_init(void)
-{
-	/*
-	 * If acpi_disabled, bail out
-	 */
-	if (acpi_disabled)
-		return 1;
 
 	/*
 	 * Process the Multiple APIC Description Table (MADT), if present
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d883176ef2ce04c1f86465b433d4a3b8ec74549e..5ecd69a48393d29c4aaac22f9e95ccb073a2b1b4 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1045,6 +1045,9 @@ void __init setup_arch(char **cmdline_p)
 
 	cleanup_highmap();
 
+	/* Look for ACPI tables and reserve memory occupied by them. */
+	acpi_boot_table_init();
+
 	memblock_set_current_limit(ISA_END_ADDRESS);
 	e820__memblock_setup();
 
@@ -1136,11 +1139,6 @@ void __init setup_arch(char **cmdline_p)
 
 	early_platform_quirks();
 
-	/*
-	 * Parse the ACPI tables for possible boot-time SMP configuration.
-	 */
-	acpi_boot_table_init();
-
 	early_acpi_boot_init();
 
 	initmem_init();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 02813a7f3a7cf98745a119aa3d3024adfcd675d8..f877150a91da11ade0e910473691693530bac64c 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1659,7 +1659,7 @@ void play_dead_common(void)
 	local_irq_disable();
 }
 
-static bool wakeup_cpu0(void)
+bool wakeup_cpu0(void)
 {
 	if (smp_processor_id() == 0 && enable_start_cpu0)
 		return true;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index d93e400940a31b28aa90139e6958cae49abdd703..768a6b4d23680b775fd5f3343a998c2c6c47ac77 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -29,6 +29,7 @@
  */
 #ifdef CONFIG_X86
 #include <asm/apic.h>
+#include <asm/cpu.h>
 #endif
 
 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
@@ -541,6 +542,12 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 			wait_for_freeze();
 		} else
 			return -ENODEV;
+
+#if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU)
+		/* If NMI wants to wake up CPU0, start CPU0. */
+		if (wakeup_cpu0())
+			start_cpu0();
+#endif
 	}
 
 	/* Never reached */
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 84bb7c1929f13def596d49a4243212f93c905cdb..6efe7edd7b1eadbf3c6b66c88c56b0fbe72fe2f8 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1670,6 +1670,8 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
 	device_initialize(&device->dev);
 	dev_set_uevent_suppress(&device->dev, true);
 	acpi_init_coherency(device);
+	/* Assume there are unmet deps to start with. */
+	device->dep_unmet = 1;
 }
 
 void acpi_device_add_finalize(struct acpi_device *device)
@@ -1933,6 +1935,8 @@ static void acpi_scan_dep_init(struct acpi_device *adev)
 {
 	struct acpi_dep_data *dep;
 
+	adev->dep_unmet = 0;
+
 	mutex_lock(&acpi_dep_list_lock);
 
 	list_for_each_entry(dep, &acpi_dep_list, node) {
@@ -1980,7 +1984,13 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
 		return AE_CTRL_DEPTH;
 
 	acpi_scan_init_hotplug(device);
-	if (!check_dep)
+	/*
+	 * If check_dep is true at this point, the device has no dependencies,
+	 * or the creation of the device object would have been postponed above.
+	 */
+	if (check_dep)
+		device->dep_unmet = 0;
+	else
 		acpi_scan_dep_init(device);
 
 out:
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index e48690a006a4e72d5b8dc3bf5fb327ee3b5e3cbc..9d581045acff079276ed81a307b60ec7244f816b 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -780,7 +780,7 @@ acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
 }
 
 /*
- * acpi_table_init()
+ * acpi_locate_initial_tables()
  *
  * find RSDP, find and checksum SDT/XSDT.
  * checksum all tables, print SDT/XSDT
@@ -788,7 +788,7 @@ acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
  * result: sdt_entry[] is initialized
  */
 
-int __init acpi_table_init(void)
+int __init acpi_locate_initial_tables(void)
 {
 	acpi_status status;
 
@@ -803,9 +803,45 @@ int __init acpi_table_init(void)
 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
 	if (ACPI_FAILURE(status))
 		return -EINVAL;
-	acpi_table_initrd_scan();
 
+	return 0;
+}
+
+void __init acpi_reserve_initial_tables(void)
+{
+	int i;
+
+	for (i = 0; i < ACPI_MAX_TABLES; i++) {
+		struct acpi_table_desc *table_desc = &initial_tables[i];
+		u64 start = table_desc->address;
+		u64 size = table_desc->length;
+
+		if (!start || !size)
+			break;
+
+		pr_info("Reserving %4s table memory at [mem 0x%llx-0x%llx]\n",
+			table_desc->signature.ascii, start, start + size - 1);
+
+		memblock_reserve(start, size);
+	}
+}
+
+void __init acpi_table_init_complete(void)
+{
+	acpi_table_initrd_scan();
 	check_multiple_madt();
+}
+
+int __init acpi_table_init(void)
+{
+	int ret;
+
+	ret = acpi_locate_initial_tables();
+	if (ret)
+		return ret;
+
+	acpi_table_init_complete();
+
 	return 0;
 }
 
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index fcdaab72391672f077de07d3ad49d1f3dc7d6eeb..3bdcfc4401b7b07980e646f5c8fcd7a37b1d9949 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -222,10 +222,14 @@ void __iomem *__acpi_map_table(unsigned long phys, unsigned long size);
 void __acpi_unmap_table(void __iomem *map, unsigned long size);
 int early_acpi_boot_init(void);
 int acpi_boot_init (void);
+void acpi_boot_table_prepare (void);
 void acpi_boot_table_init (void);
 int acpi_mps_check (void);
 int acpi_numa_init (void);
 
+int acpi_locate_initial_tables (void);
+void acpi_reserve_initial_tables (void);
+void acpi_table_init_complete (void);
 int acpi_table_init (void);
 int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
 int __init acpi_table_parse_entries(char *id, unsigned long table_size,
@@ -814,9 +818,12 @@ static inline int acpi_boot_init(void)
 	return 0;
 }
 
+static inline void acpi_boot_table_prepare(void)
+{
+}
+
 static inline void acpi_boot_table_init(void)
 {
-	return;
 }
 
 static inline int acpi_mps_check(void)