diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5a92d89a1bd4..ade4e6ec23e0 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -113,7 +113,7 @@
 			the GPE dispatcher.
 			This facility can be used to prevent such uncontrolled
 			GPE floodings.
-			Format: <int>
+			Format: <byte>
 
 	acpi_no_auto_serialize	[HW,ACPI]
 			Disable auto-serialization of AML methods
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 4fb97511a16f..002838d23b86 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -104,9 +104,9 @@ config ACPI_PROCFS_POWER
 	depends on X86 && PROC_FS
 	help
 	  For backwards compatibility, this option allows
-          deprecated power /proc/acpi/ directories to exist, even when
-          they have been replaced by functions in /sys.
-          The deprecated directories (and their replacements) include:
+	  deprecated power /proc/acpi/ directories to exist, even when
+	  they have been replaced by functions in /sys.
+	  The deprecated directories (and their replacements) include:
 	  /proc/acpi/battery/* (/sys/class/power_supply/*) and
 	  /proc/acpi/ac_adapter/* (sys/class/power_supply/*).
 	  This option has no effect on /proc/acpi/ directories
@@ -448,7 +448,7 @@ config ACPI_CUSTOM_METHOD
 config ACPI_BGRT
 	bool "Boottime Graphics Resource Table support"
 	depends on EFI && (X86 || ARM64)
-        help
+	help
 	  This driver adds support for exposing the ACPI Boottime Graphics
 	  Resource Table, which allows the operating system to obtain
 	  data from the firmware boot splash. It will appear under
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 48bc96d45bab..54002670cb7a 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -153,7 +153,7 @@ int acpi_bus_get_private_data(acpi_handle handle, void **data)
 {
 	acpi_status status;
 
-	if (!*data)
+	if (!data)
 		return -EINVAL;
 
 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index d27b01c0323d..b758b45737f5 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -77,6 +77,19 @@ MODULE_DEVICE_TABLE(acpi, button_device_ids);
 
 /* Please keep this list sorted alphabetically by vendor and model */
 static const struct dmi_system_id dmi_lid_quirks[] = {
+	{
+		/*
+		 * Acer Switch 10 SW5-012. _LID method messes with home and
+		 * power button GPIO IRQ settings causing an interrupt storm on
+		 * both GPIOs. This is unfixable without a DSDT override, so we
+		 * have to disable the lid-switch functionality altogether :|
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire SW5-012"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
+	},
 	{
 		/*
 		 * Asus T200TA, _LID keeps reporting closed after every second
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index a2e844a8e9ed..41168c027a5a 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -374,19 +374,21 @@ void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
 }
 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
 
-static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
+/* Must be called with mutex_lock(&acpi_ioremap_lock) */
+static unsigned long acpi_os_drop_map_ref(struct acpi_ioremap *map)
 {
-	if (!--map->refcount)
+	unsigned long refcount = --map->refcount;
+
+	if (!refcount)
 		list_del_rcu(&map->list);
+	return refcount;
 }
 
 static void acpi_os_map_cleanup(struct acpi_ioremap *map)
 {
-	if (!map->refcount) {
-		synchronize_rcu_expedited();
-		acpi_unmap(map->phys, map->virt);
-		kfree(map);
-	}
+	synchronize_rcu_expedited();
+	acpi_unmap(map->phys, map->virt);
+	kfree(map);
 }
 
 /**
@@ -406,6 +408,7 @@ static void acpi_os_map_cleanup(struct acpi_ioremap *map)
 void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
 {
 	struct acpi_ioremap *map;
+	unsigned long refcount;
 
 	if (!acpi_permanent_mmap) {
 		__acpi_unmap_table(virt, size);
@@ -419,10 +422,11 @@ void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
 		WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
 		return;
 	}
-	acpi_os_drop_map_ref(map);
+	refcount = acpi_os_drop_map_ref(map);
 	mutex_unlock(&acpi_ioremap_lock);
 
-	acpi_os_map_cleanup(map);
+	if (!refcount)
+		acpi_os_map_cleanup(map);
 }
 EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem);
 
@@ -457,6 +461,7 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
 {
 	u64 addr;
 	struct acpi_ioremap *map;
+	unsigned long refcount;
 
 	if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		return;
@@ -472,10 +477,11 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
 		mutex_unlock(&acpi_ioremap_lock);
 		return;
 	}
-	acpi_os_drop_map_ref(map);
+	refcount = acpi_os_drop_map_ref(map);
 	mutex_unlock(&acpi_ioremap_lock);
 
-	acpi_os_map_cleanup(map);
+	if (!refcount)
+		acpi_os_map_cleanup(map);
 }
 EXPORT_SYMBOL(acpi_os_unmap_generic_address);
 
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 75948a3f1a20..c60d2c6d31d6 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -819,14 +819,14 @@ end:
  * interface:
  *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
  */
-#define ACPI_MASKABLE_GPE_MAX	0xFF
+#define ACPI_MASKABLE_GPE_MAX	0x100
 static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
 
 static int __init acpi_gpe_set_masked_gpes(char *val)
 {
 	u8 gpe;
 
-	if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
+	if (kstrtou8(val, 0, &gpe))
 		return -EINVAL;
 	set_bit(gpe, acpi_masked_gpes_map);
 
@@ -838,7 +838,7 @@ void __init acpi_gpe_apply_masked_gpes(void)
 {
 	acpi_handle handle;
 	acpi_status status;
-	u8 gpe;
+	u16 gpe;
 
 	for_each_set_bit(gpe, acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) {
 		status = acpi_get_gpe_device(gpe, &handle);