Merge tag 'acpi-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These eliminate significant AML processing overhead related to using
  operation regions in system memory, update the ACPICA code in the
  kernel to upstream revision 20200717 (including a fix to prevent
  operation region reference counts from overflowing in some cases),
  remove the last bits of the (long deprecated) ACPI procfs interface
  and do some assorted cleanups.

  Specifics:

   - Eliminate significant AML processing overhead related to using
     operation regions in system memory by reworking the management of
     memory mappings in the ACPI code to defer unmap operations (to do
     them outside of the ACPICA locks, among other things) and making
     the memory operation reagion handler avoid releasing memory
     mappings created by it too early (Rafael Wysocki).

   - Update the ACPICA code in the kernel to upstream revision 20200717:

       * Prevent operation region reference counts from overflowing in
         some cases (Erik Kaneda).

       * Replace one-element array with flexible-array (Gustavo A. R.
         Silva).

   - Fix ACPI PCI hotplug reference counting (Rafael Wysocki).

   - Drop last bits of the ACPI procfs interface (Thomas Renninger).

   - Drop some redundant checks from the code parsing ACPI tables
     related to NUMA (Hanjun Guo).

   - Avoid redundant object evaluation in the ACPI device properties
     handling code (Heikki Krogerus).

   - Avoid unecessary memory overhead related to storing the signatures
     of the ACPI tables recognized by the kernel (Ard Biesheuvel).

   - Add missing newline characters when printing module parameter
     values in some places (Xiongfeng Wang).

   - Update the link to the ACPI specifications in some places (Tiezhu
     Yang).

   - Use the fallthrough pseudo-keyword in the ACPI code (Gustavo A. R.
     Silva).

   - Drop redundant variable initialization from the APEI code (Colin
     Ian King).

   - Drop uninitialized_var() from the ACPI PAD driver (Jason Yan).

   - Replace HTTP links with HTTPS ones in the ACPI code (Alexander A.
     Klimov)"

* tag 'acpi-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits)
  ACPI: APEI: remove redundant assignment to variable rc
  ACPI: NUMA: Remove the useless 'node >= MAX_NUMNODES' check
  ACPI: NUMA: Remove the useless sub table pointer check
  ACPI: tables: Remove the duplicated checks for acpi_parse_entries_array()
  ACPICA: Update version to 20200717
  ACPICA: Do not increment operation_region reference counts for field units
  ACPICA: Replace one-element array with flexible-array
  ACPI: Replace HTTP links with HTTPS ones
  ACPI: Use valid link to the ACPI specification
  ACPI: OSL: Clean up the removal of unused memory mappings
  ACPI: OSL: Use deferred unmapping in acpi_os_unmap_iomem()
  ACPI: OSL: Use deferred unmapping in acpi_os_unmap_generic_address()
  ACPICA: Preserve memory opregion mappings
  ACPI: OSL: Implement deferred unmapping of ACPI memory
  ACPI: Use fallthrough pseudo-keyword
  PCI: hotplug: ACPI: Fix context refcounting in acpiphp_grab_context()
  ACPI: tables: avoid relocations for table signature array
  ACPI: PAD: Eliminate usage of uninitialized_var() macro
  ACPI: sysfs: add newlines when printing module parameters
  ACPI: EC: add newline when printing 'ec_event_clearing' module parameter
  ...

26 files changed, 126 insertions, 593 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ce2730d61a8f..7540a5179a47 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -32,7 +32,7 @@ menuconfig ACPI
 	  Linux support for ACPI is based on Intel Corporation's ACPI
 	  Component Architecture (ACPI CA).  For more information on the
 	  ACPI CA, see:
-	  <http://acpica.org/>
+	  <https://acpica.org/>
 
 	  ACPI is an open industry specification originally co-developed by
 	  Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. Currently,
@@ -40,8 +40,7 @@ menuconfig ACPI
 	  the UEFI Forum and any UEFI member can join the ASWG and contribute
 	  to the ACPI specification.
 	  The specification is available at:
-	  <http://www.acpi.info>
-	  <http://www.uefi.org/acpi/specs>
+	  <https://uefi.org/specifications>
 
 if ACPI
 
@@ -99,23 +98,6 @@ config ACPI_SLEEP
 	depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
 	default y
 
-config ACPI_PROCFS_POWER
-	bool "Deprecated power /proc/acpi directories"
-	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:
-	  /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
-	  and functions which do not yet exist in /sys.
-	  This option, together with the proc directories, will be
-	  deleted in the future.
-
-	  Say N to delete power /proc/acpi/ directories that have moved to /sys.
-
 config ACPI_REV_OVERRIDE_POSSIBLE
 	bool "Allow supported ACPI revision to be overridden"
 	depends on X86
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index e81e1ebbfb32..9a957544e357 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -55,7 +55,6 @@ acpi-$(CONFIG_X86)		+= acpi_cmos_rtc.o
 acpi-$(CONFIG_X86)		+= x86/apple.o
 acpi-$(CONFIG_X86)		+= x86/utils.o
 acpi-$(CONFIG_DEBUG_FS)		+= debugfs.o
-acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
 acpi-y				+= acpi_lpat.o
 acpi-$(CONFIG_ACPI_LPIT)	+= acpi_lpit.o
 acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
index 69d2db13886b..46a64e9fa716 100644
--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -13,10 +13,6 @@
 #include <linux/types.h>
 #include <linux/dmi.h>
 #include <linux/delay.h>
-#ifdef CONFIG_ACPI_PROCFS_POWER
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#endif
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/acpi.h>
@@ -66,12 +62,6 @@ static int acpi_ac_resume(struct device *dev);
 #endif
 static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume);
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-extern struct proc_dir_entry *acpi_lock_ac_dir(void);
-extern void *acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir);
-#endif
-
-
 static int ac_sleep_before_get_state_ms;
 static int ac_check_pmic = 1;
 
@@ -150,77 +140,6 @@ static enum power_supply_property ac_props[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 };
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-/* --------------------------------------------------------------------------
-                              FS Interface (/proc)
-   -------------------------------------------------------------------------- */
-
-static struct proc_dir_entry *acpi_ac_dir;
-
-static int acpi_ac_seq_show(struct seq_file *seq, void *offset)
-{
-	struct acpi_ac *ac = seq->private;
-
-
-	if (!ac)
-		return 0;
-
-	if (acpi_ac_get_state(ac)) {
-		seq_puts(seq, "ERROR: Unable to read AC Adapter state\n");
-		return 0;
-	}
-
-	seq_puts(seq, "state:                   ");
-	switch (ac->state) {
-	case ACPI_AC_STATUS_OFFLINE:
-		seq_puts(seq, "off-line\n");
-		break;
-	case ACPI_AC_STATUS_ONLINE:
-		seq_puts(seq, "on-line\n");
-		break;
-	default:
-		seq_puts(seq, "unknown\n");
-		break;
-	}
-
-	return 0;
-}
-
-static int acpi_ac_add_fs(struct acpi_ac *ac)
-{
-	struct proc_dir_entry *entry = NULL;
-
-	printk(KERN_WARNING PREFIX "Deprecated procfs I/F for AC is loaded,"
-			" please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
-	if (!acpi_device_dir(ac->device)) {
-		acpi_device_dir(ac->device) =
-			proc_mkdir(acpi_device_bid(ac->device), acpi_ac_dir);
-		if (!acpi_device_dir(ac->device))
-			return -ENODEV;
-	}
-
-	/* 'state' [R] */
-	entry = proc_create_single_data(ACPI_AC_FILE_STATE, S_IRUGO,
-			acpi_device_dir(ac->device), acpi_ac_seq_show, ac);
-	if (!entry)
-		return -ENODEV;
-	return 0;
-}
-
-static int acpi_ac_remove_fs(struct acpi_ac *ac)
-{
-
-	if (acpi_device_dir(ac->device)) {
-		remove_proc_entry(ACPI_AC_FILE_STATE,
-				  acpi_device_dir(ac->device));
-		remove_proc_entry(acpi_device_bid(ac->device), acpi_ac_dir);
-		acpi_device_dir(ac->device) = NULL;
-	}
-
-	return 0;
-}
-#endif
-
 /* --------------------------------------------------------------------------
                                    Driver Model
    -------------------------------------------------------------------------- */
@@ -236,7 +155,7 @@ static void acpi_ac_notify(struct acpi_device *device, u32 event)
 	default:
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 				  "Unsupported event [0x%x]\n", event));
-	/* fall through */
+		fallthrough;
 	case ACPI_AC_NOTIFY_STATUS:
 	case ACPI_NOTIFY_BUS_CHECK:
 	case ACPI_NOTIFY_DEVICE_CHECK:
@@ -348,11 +267,6 @@ static int acpi_ac_add(struct acpi_device *device)
 	psy_cfg.drv_data = ac;
 
 	ac->charger_desc.name = acpi_device_bid(device);
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	result = acpi_ac_add_fs(ac);
-	if (result)
-		goto end;
-#endif
 	ac->charger_desc.type = POWER_SUPPLY_TYPE_MAINS;
 	ac->charger_desc.properties = ac_props;
 	ac->charger_desc.num_properties = ARRAY_SIZE(ac_props);
@@ -372,9 +286,6 @@ static int acpi_ac_add(struct acpi_device *device)
 	register_acpi_notifier(&ac->battery_nb);
 end:
 	if (result) {
-#ifdef CONFIG_ACPI_PROCFS_POWER
-		acpi_ac_remove_fs(ac);
-#endif
 		kfree(ac);
 	}
 
@@ -418,10 +329,6 @@ static int acpi_ac_remove(struct acpi_device *device)
 	power_supply_unregister(ac->charger);
 	unregister_acpi_notifier(&ac->battery_nb);
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	acpi_ac_remove_fs(ac);
-#endif
-
 	kfree(ac);
 
 	return 0;
@@ -447,18 +354,8 @@ static int __init acpi_ac_init(void)
 			}
 	}
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	acpi_ac_dir = acpi_lock_ac_dir();
-	if (!acpi_ac_dir)
-		return -ENODEV;
-#endif
-
-
 	result = acpi_bus_register_driver(&acpi_ac_driver);
 	if (result < 0) {
-#ifdef CONFIG_ACPI_PROCFS_POWER
-		acpi_unlock_ac_dir(acpi_ac_dir);
-#endif
 		return -ENODEV;
 	}
 
@@ -468,9 +365,6 @@ static int __init acpi_ac_init(void)
 static void __exit acpi_ac_exit(void)
 {
 	acpi_bus_unregister_driver(&acpi_ac_driver);
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	acpi_unlock_ac_dir(acpi_ac_dir);
-#endif
 }
 module_init(acpi_ac_init);
 module_exit(acpi_ac_exit);
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index e7dc0133f817..6cc4c92d9ff9 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index)
 	cpumask_var_t tmp;
 	int cpu;
 	unsigned long min_weight = -1;
-	unsigned long uninitialized_var(preferred_cpu);
+	unsigned long preferred_cpu;
 
 	if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
 		return;
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 5379bc3f275d..b51ddf3bb616 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -79,7 +79,7 @@ static int acpi_processor_errata_piix4(struct pci_dev *dev)
 		 * PIIX4 models.
 		 */
 		errata.piix4.throttle = 1;
-		/* fall through*/
+		fallthrough;
 
 	case 2:		/* PIIX4E */
 	case 3:		/* PIIX4M */
diff --git a/drivers/acpi/acpica/evrgnini.c b/drivers/acpi/acpica/evrgnini.c
index aefc0145e583..89be3ccdad53 100644
--- a/drivers/acpi/acpica/evrgnini.c
+++ b/drivers/acpi/acpica/evrgnini.c
@@ -38,6 +38,7 @@ acpi_ev_system_memory_region_setup(acpi_handle handle,
 	union acpi_operand_object *region_desc =
 	    (union acpi_operand_object *)handle;
 	struct acpi_mem_space_context *local_region_context;
+	struct acpi_mem_mapping *mm;
 
 	ACPI_FUNCTION_TRACE(ev_system_memory_region_setup);
 
@@ -46,13 +47,14 @@ acpi_ev_system_memory_region_setup(acpi_handle handle,
 			local_region_context =
 			    (struct acpi_mem_space_context *)*region_context;
 
-			/* Delete a cached mapping if present */
+			/* Delete memory mappings if present */
 
-			if (local_region_context->mapped_length) {
-				acpi_os_unmap_memory(local_region_context->
-						     mapped_logical_address,
-						     local_region_context->
-						     mapped_length);
+			while (local_region_context->first_mm) {
+				mm = local_region_context->first_mm;
+				local_region_context->first_mm = mm->next_mm;
+				acpi_os_unmap_memory(mm->logical_address,
+						     mm->length);
+				ACPI_FREE(mm);
 			}
 			ACPI_FREE(local_region_context);
 			*region_context = NULL;
diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c
index a4e306690a21..4a0f03157e08 100644
--- a/drivers/acpi/acpica/exprep.c
+++ b/drivers/acpi/acpica/exprep.c
@@ -473,10 +473,6 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
 				    (u8)access_byte_width;
 			}
 		}
-		/* An additional reference for the container */
-
-		acpi_ut_add_reference(obj_desc->field.region_obj);
-
 		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 				  "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
 				  obj_desc->field.start_field_bit_offset,
diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c
index d15a66de26c0..4914dbc44517 100644
--- a/drivers/acpi/acpica/exregion.c
+++ b/drivers/acpi/acpica/exregion.c
@@ -41,6 +41,7 @@ acpi_ex_system_memory_space_handler(u32 function,
 	acpi_status status = AE_OK;
 	void *logical_addr_ptr = NULL;
 	struct acpi_mem_space_context *mem_info = region_context;
+	struct acpi_mem_mapping *mm = mem_info->cur_mm;
 	u32 length;
 	acpi_size map_length;
 	acpi_size page_boundary_map_length;
@@ -96,20 +97,37 @@ acpi_ex_system_memory_space_handler(u32 function,
 	 * Is 1) Address below the current mapping? OR
 	 *    2) Address beyond the current mapping?
 	 */
-	if ((address < mem_info->mapped_physical_address) ||
-	    (((u64) address + length) > ((u64)
-					 mem_info->mapped_physical_address +
-					 mem_info->mapped_length))) {
+	if (!mm || (address < mm->physical_address) ||
+	    ((u64) address + length > (u64) mm->physical_address + mm->length)) {
 		/*
-		 * The request cannot be resolved by the current memory mapping;
-		 * Delete the existing mapping and create a new one.
+		 * The request cannot be resolved by the current memory mapping.
+		 *
+		 * Look for an existing saved mapping covering the address range
+		 * at hand.  If found, save it as the current one and carry out
+		 * the access.
 		 */
-		if (mem_info->mapped_length) {
+		for (mm = mem_info->first_mm; mm; mm = mm->next_mm) {
+			if (mm == mem_info->cur_mm)
+				continue;
+
+			if (address < mm->physical_address)
+				continue;
 
-			/* Valid mapping, delete it */
+			if ((u64) address + length >
+					(u64) mm->physical_address + mm->length)
+				continue;
 
-			acpi_os_unmap_memory(mem_info->mapped_logical_address,
-					     mem_info->mapped_length);
+			mem_info->cur_mm = mm;
+			goto access;
+		}
+
+		/* Create a new mappings list entry */
+		mm = ACPI_ALLOCATE_ZEROED(sizeof(*mm));
+		if (!mm) {
+			ACPI_ERROR((AE_INFO,
+				    "Unable to save memory mapping at 0x%8.8X%8.8X, size %u",
+				    ACPI_FORMAT_UINT64(address), length));
+			return_ACPI_STATUS(AE_NO_MEMORY);
 		}
 
 		/*
@@ -143,29 +161,39 @@ acpi_ex_system_memory_space_handler(u32 function,
 
 		/* Create a new mapping starting at the address given */
 
-		mem_info->mapped_logical_address =
-		    acpi_os_map_memory(address, map_length);
-		if (!mem_info->mapped_logical_address) {
+		logical_addr_ptr = acpi_os_map_memory(address, map_length);
+		if (!logical_addr_ptr) {
 			ACPI_ERROR((AE_INFO,
 				    "Could not map memory at 0x%8.8X%8.8X, size %u",
 				    ACPI_FORMAT_UINT64(address),
 				    (u32)map_length));
-			mem_info->mapped_length = 0;
+			ACPI_FREE(mm);
 			return_ACPI_STATUS(AE_NO_MEMORY);
 		}
 
 		/* Save the physical address and mapping size */
 
-		mem_info->mapped_physical_address = address;
-		mem_info->mapped_length = map_length;
+		mm->logical_address = logical_addr_ptr;
+		mm->physical_address = address;
+		mm->length = map_length;
+
+		/*
+		 * Add the new entry to the mappigs list and save it as the
+		 * current mapping.
+		 */
+		mm->next_mm = mem_info->first_mm;
+		mem_info->first_mm = mm;
+
+		mem_info->cur_mm = mm;
 	}
 
+access:
 	/*
 	 * Generate a logical pointer corresponding to the address we want to
 	 * access
 	 */
-	logical_addr_ptr = mem_info->mapped_logical_address +
-	    ((u64) address - (u64) mem_info->mapped_physical_address);
+	logical_addr_ptr = mm->logical_address +
+		((u64) address - (u64) mm->physical_address);
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 			  "System-Memory (width %u) R/W %u Address=%8.8X%8.8X\n",
diff --git a/drivers/acpi/acpica/utdelete.c b/drivers/acpi/acpica/utdelete.c
index c365faf4e6cd..4c0d4e434196 100644
--- a/drivers/acpi/acpica/utdelete.c
+++ b/drivers/acpi/acpica/utdelete.c
@@ -568,11 +568,6 @@ acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 			next_object = object->buffer_field.buffer_obj;
 			break;
 
-		case ACPI_TYPE_LOCAL_REGION_FIELD:
-
-			next_object = object->field.region_obj;
-			break;
-
 		case ACPI_TYPE_LOCAL_BANK_FIELD:
 
 			next_object = object->bank_field.bank_obj;
@@ -613,6 +608,7 @@ acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 			}
 			break;
 
+		case ACPI_TYPE_LOCAL_REGION_FIELD:
 		case ACPI_TYPE_REGION:
 		default:
 
diff --git a/drivers/acpi/acpica/utids.c b/drivers/acpi/acpica/utids.c
index 3bb06935a2ad..3e68864ef242 100644
--- a/drivers/acpi/acpica/utids.c
+++ b/drivers/acpi/acpica/utids.c
@@ -263,8 +263,7 @@ acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
 	 * 3) Size of the actual CID strings
 	 */
 	cid_list_size = sizeof(struct acpi_pnp_device_id_list) +
-	    ((count - 1) * sizeof(struct acpi_pnp_device_id)) +
-	    string_area_size;
+	    (count * sizeof(struct acpi_pnp_device_id)) + string_area_size;
 
 	cid_list = ACPI_ALLOCATE_ZEROED(cid_list_size);
 	if (!cid_list) {
diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c
index 953a2fae8b15..6e980fe16772 100644
--- a/drivers/acpi/apei/hest.c
+++ b/drivers/acpi/apei/hest.c
@@ -227,7 +227,7 @@ __setup("hest_disable", setup_hest_disable);
 void __init acpi_hest_init(void)
 {
 	acpi_status status;
-	int rc = -ENODEV;
+	int rc;
 	unsigned int ghes_count = 0;
 
 	if (hest_disable) {
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 366c389175d8..cab4af532f36 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -24,12 +24,6 @@
 
 #include <asm/unaligned.h>
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/uaccess.h>
-#endif
-
 #include <linux/acpi.h>
 #include <linux/power_supply.h>
 
@@ -69,11 +63,6 @@ static unsigned int cache_time = 1000;
 module_param(cache_time, uint, 0644);
 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-extern struct proc_dir_entry *acpi_lock_battery_dir(void);
-extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
-#endif
-
 static const struct acpi_device_id battery_device_ids[] = {
 	{"PNP0C0A", 0},
 	{"", 0},
@@ -1024,226 +1013,6 @@ static void acpi_battery_refresh(struct acpi_battery *battery)
 }
 
 /* --------------------------------------------------------------------------
-                              FS Interface (/proc)
-   -------------------------------------------------------------------------- */
-
-#ifdef CONFIG_ACPI_PROCFS_POWER
-static struct proc_dir_entry *acpi_battery_dir;
-
-static const char *acpi_battery_units(const struct acpi_battery *battery)
-{
-	return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
-		"mA" : "mW";
-}
-
-static int acpi_battery_info_proc_show(struct seq_file *seq, void *offset)
-{
-	struct acpi_battery *battery = seq->private;
-	int result = acpi_battery_update(battery, false);
-
-	if (result)
-		goto end;
-
-	seq_printf(seq, "present:                 %s\n",
-		   acpi_battery_present(battery) ? "yes" : "no");
-	if (!acpi_battery_present(battery))
-		goto end;
-	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "design capacity:         unknown\n");
-	else
-		seq_printf(seq, "design capacity:         %d %sh\n",
-			   battery->design_capacity,
-			   acpi_battery_units(battery));
-
-	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "last full capacity:      unknown\n");
-	else
-		seq_printf(seq, "last full capacity:      %d %sh\n",
-			   battery->full_charge_capacity,
-			   acpi_battery_units(battery));
-
-	seq_printf(seq, "battery technology:      %srechargeable\n",
-		   battery->technology ? "" : "non-");
-
-	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "design voltage:          unknown\n");
-	else
-		seq_printf(seq, "design voltage:          %d mV\n",
-			   battery->design_voltage);
-	seq_printf(seq, "design capacity warning: %d %sh\n",
-		   battery->design_capacity_warning,
-		   acpi_battery_units(battery));
-	seq_printf(seq, "design capacity low:     %d %sh\n",
-		   battery->design_capacity_low,
-		   acpi_battery_units(battery));
-	seq_printf(seq, "cycle count:		  %i\n", battery->cycle_count);
-	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
-		   battery->capacity_granularity_1,
-		   acpi_battery_units(battery));
-	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
-		   battery->capacity_granularity_2,
-		   acpi_battery_units(battery));
-	seq_printf(seq, "model number:            %s\n", battery->model_number);
-	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
-	seq_printf(seq, "battery type:            %s\n", battery->type);
-	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
-      end:
-	if (result)
-		seq_printf(seq, "ERROR: Unable to read battery info\n");
-	return result;
-}
-
-static int acpi_battery_state_proc_show(struct seq_file *seq, void *offset)
-{
-	struct acpi_battery *battery = seq->private;
-	int result = acpi_battery_update(battery, false);
-
-	if (result)
-		goto end;
-
-	seq_printf(seq, "present:                 %s\n",
-		   acpi_battery_present(battery) ? "yes" : "no");
-	if (!acpi_battery_present(battery))
-		goto end;
-
-	seq_printf(seq, "capacity state:          %s\n",
-			(battery->state & 0x04) ? "critical" : "ok");
-	if ((battery->state & 0x01) && (battery->state & 0x02))
-		seq_printf(seq,
-			   "charging state:          charging/discharging\n");
-	else if (battery->state & 0x01)
-		seq_printf(seq, "charging state:          discharging\n");
-	else if (battery->state & 0x02)
-		seq_printf(seq, "charging state:          charging\n");
-	else
-		seq_printf(seq, "charging state:          charged\n");
-
-	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "present rate:            unknown\n");
-	else
-		seq_printf(seq, "present rate:            %d %s\n",
-			   battery->rate_now, acpi_battery_units(battery));
-
-	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "remaining capacity:      unknown\n");
-	else
-		seq_printf(seq, "remaining capacity:      %d %sh\n",
-			   battery->capacity_now, acpi_battery_units(battery));
-	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
-		seq_printf(seq, "present voltage:         unknown\n");
-	else
-		seq_printf(seq, "present voltage:         %d mV\n",
-			   battery->voltage_now);
-      end:
-	if (result)
-		seq_printf(seq, "ERROR: Unable to read battery state\n");
-
-	return result;
-}
-
-static int acpi_battery_alarm_proc_show(struct seq_file *seq, void *offset)
-{
-	struct acpi_battery *battery = seq->private;
-	int result = acpi_battery_update(battery, false);
-
-	if (result)
-		goto end;
-
-	if (!acpi_battery_present(battery)) {
-		seq_printf(seq, "present:                 no\n");
-		goto end;
-	}
-	seq_printf(seq, "alarm:                   ");
-	if (battery->alarm) {
-		seq_printf(seq, "%u %sh\n", battery->alarm,
-				acpi_battery_units(battery));
-	} else {
-		seq_printf(seq, "unsupported\n");
-	}
-      end:
-	if (result)
-		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
-	return result;
-}
-
-static ssize_t acpi_battery_write_alarm(struct file *file,
-					const char __user * buffer,
-					size_t count, loff_t * ppos)
-{
-	int result = 0;
-	char alarm_string[12] = { '\0' };
-	struct seq_file *m = file->private_data;
-	struct acpi_battery *battery = m->private;
-
-	if (!battery || (count > sizeof(alarm_string) - 1))
-		return -EINVAL;
-	if (!acpi_battery_present(battery)) {
-		result = -ENODEV;
-		goto end;
-	}
-	if (copy_from_user(alarm_string, buffer, count)) {
-		result = -EFAULT;
-		goto end;
-	}
-	alarm_string[count] = '\0';
-	if (kstrtoint(alarm_string, 0, &battery->alarm)) {
-		result = -EINVAL;
-		goto end;
-	}
-	result = acpi_battery_set_alarm(battery);
-      end:
-	if (result)
-		return result;
-	return count;
-}
-
-static int acpi_battery_alarm_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, acpi_battery_alarm_proc_show, PDE_DATA(inode));
-}
-
-static const struct proc_ops acpi_battery_alarm_proc_ops = {
-	.proc_open	= acpi_battery_alarm_proc_open,
-	.proc_read	= seq_read,
-	.proc_write	= acpi_battery_write_alarm,
-	.proc_lseek	= seq_lseek,
-	.proc_release	= single_release,
-};
-
-static int acpi_battery_add_fs(struct acpi_device *device)
-{
-	pr_warn(PREFIX "Deprecated procfs I/F for battery is loaded, please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
-	if (!acpi_device_dir(device)) {
-		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
-						     acpi_battery_dir);
-		if (!acpi_device_dir(device))
-			return -ENODEV;
-	}
-
-	if (!proc_create_single_data("info", S_IRUGO, acpi_device_dir(device),
-			acpi_battery_info_proc_show, acpi_driver_data(device)))
-		return -ENODEV;
-	if (!proc_create_single_data("state", S_IRUGO, acpi_device_dir(device),
-			acpi_battery_state_proc_show, acpi_driver_data(device)))
-		return -ENODEV;
-	if (!proc_create_data("alarm", S_IFREG | S_IRUGO | S_IWUSR,
-			acpi_device_dir(device), &acpi_battery_alarm_proc_ops,
-			acpi_driver_data(device)))
-		return -ENODEV;
-	return 0;
-}
-
-static void acpi_battery_remove_fs(struct acpi_device *device)
-{
-	if (!acpi_device_dir(device))
-		return;
-	remove_proc_subtree(acpi_device_bid(device), acpi_battery_dir);
-	acpi_device_dir(device) = NULL;
-}
-
-#endif
-
-/* --------------------------------------------------------------------------
                                  Driver Interface
    -------------------------------------------------------------------------- */
 
@@ -1432,14 +1201,6 @@ static int acpi_battery_add(struct acpi_device *device)
 	if (result)
 		goto fail;
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	result = acpi_battery_add_fs(device);
-	if (result) {
-		acpi_battery_remove_fs(device);
-		goto fail;
-	}
-#endif
-
 	pr_info(PREFIX "%s Slot [%s] (battery %s)\n",
 		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
 		device->status.battery_present ? "present" : "absent");
@@ -1468,9 +1229,6 @@ static int acpi_battery_remove(struct acpi_device *device)
 	device_init_wakeup(&device->dev, 0);
 	battery = acpi_driver_data(device);
 	unregister_pm_notifier(&battery->pm_nb);
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	acpi_battery_remove_fs(device);
-#endif
 	sysfs_remove_battery(battery);
 	mutex_destroy(&battery->lock);
 	mutex_destroy(&battery->sysfs_lock);
@@ -1531,16 +1289,7 @@ static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
 			}
 	}
 
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	acpi_battery_dir = acpi_lock_battery_dir();
-	if (!acpi_battery_dir)
-		return;
-#endif
 	result = acpi_bus_register_driver(&acpi_battery_driver);
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	if (result < 0)
-		acpi_unlock_battery_dir(acpi_battery_dir);
-#endif
 	battery_driver_registered = (result == 0);
 }
 
@@ -1560,10 +1309,6 @@ static void __exit acpi_battery_exit(void)
 		acpi_bus_unregister_driver(&acpi_battery_driver);
 		battery_hook_exit();
 	}
-#ifdef CONFIG_ACPI_PROCFS_POWER
-	if (acpi_battery_dir)
-		acpi_unlock_battery_dir(acpi_battery_dir);
-#endif
 }
 
 module_init(acpi_battery_init);
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 3c35e57dd854..a4eda7fe50d3 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -405,7 +405,7 @@ static void acpi_button_notify(struct acpi_device *device, u32 event)
 	switch (event) {
 	case ACPI_FIXED_HARDWARE_EVENT:
 		event = ACPI_BUTTON_NOTIFY_STATUS;
-		/* fall through */
+		fallthrough;
 	case ACPI_BUTTON_NOTIFY_STATUS:
 		input = button->input;
 		if (button->type == ACPI_BUTTON_TYPE_LID) {
diff --git a/drivers/acpi/cm_sbs.c b/drivers/acpi/cm_sbs.c
deleted file mode 100644
index 0ca9f82de8ba..000000000000
--- a/drivers/acpi/cm_sbs.c
+++ /dev/null
@@ -1,87 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/acpi.h>
-#include <linux/types.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
-
-#define PREFIX "ACPI: "
-
-ACPI_MODULE_NAME("cm_sbs");
-#define ACPI_AC_CLASS		"ac_adapter"
-#define ACPI_BATTERY_CLASS	"battery"
-#define _COMPONENT		ACPI_SBS_COMPONENT
-static struct proc_dir_entry *acpi_ac_dir;
-static struct proc_dir_entry *acpi_battery_dir;
-
-static DEFINE_MUTEX(cm_sbs_mutex);
-
-static int lock_ac_dir_cnt;
-static int lock_battery_dir_cnt;
-
-struct proc_dir_entry *acpi_lock_ac_dir(void)
-{
-	mutex_lock(&cm_sbs_mutex);
-	if (!acpi_ac_dir)
-		acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);
-	if (acpi_ac_dir) {
-		lock_ac_dir_cnt++;
-	} else {
-		printk(KERN_ERR PREFIX
-				  "Cannot create %s\n", ACPI_AC_CLASS);
-	}
-	mutex_unlock(&cm_sbs_mutex);
-	return acpi_ac_dir;
-}
-EXPORT_SYMBOL(acpi_lock_ac_dir);
-
-void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)
-{
-	mutex_lock(&cm_sbs_mutex);
-	if (acpi_ac_dir_param)
-		lock_ac_dir_cnt--;
-	if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {
-		remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);
-		acpi_ac_dir = NULL;
-	}
-	mutex_unlock(&cm_sbs_mutex);
-}
-EXPORT_SYMBOL(acpi_unlock_ac_dir);
-
-struct proc_dir_entry *acpi_lock_battery_dir(void)
-{
-	mutex_lock(&cm_sbs_mutex);
-	if (!acpi_battery_dir) {
-		acpi_battery_dir =
-		    proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
-	}
-	if (acpi_battery_dir) {
-		lock_battery_dir_cnt++;
-	} else {
-		printk(KERN_ERR PREFIX
-				  "Cannot create %s\n", ACPI_BATTERY_CLASS);
-	}
-	mutex_unlock(&cm_sbs_mutex);
-	return acpi_battery_dir;
-}
-EXPORT_SYMBOL(acpi_lock_battery_dir);
-
-void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)
-{
-	mutex_lock(&cm_sbs_mutex);
-	if (acpi_battery_dir_param)
-		lock_battery_dir_cnt--;
-	if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param
-	    && acpi_battery_dir) {
-		remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);
-		acpi_battery_dir = NULL;
-	}
-	mutex_unlock(&cm_sbs_mutex);
-	return;
-}
-EXPORT_SYMBOL(acpi_unlock_battery_dir);
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index e3414131bfca..9bd72c26ef46 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -469,7 +469,7 @@ int dock_notify(struct acpi_device *adev, u32 event)
 		surprise_removal = 1;
 		event = ACPI_NOTIFY_EJECT_REQUEST;
 		/* Fall back */
-		/* fall through */
+		fallthrough;
 	case ACPI_NOTIFY_EJECT_REQUEST:
 		begin_undock(ds);
 		if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 04ce2b96c3da..fcddda3d6712 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -2059,13 +2059,13 @@ static int param_get_event_clearing(char *buffer,
 {
 	switch (ec_event_clearing) {
 	case ACPI_EC_EVT_TIMING_STATUS:
-		return sprintf(buffer, "status");
+		return sprintf(buffer, "status\n");
 	case ACPI_EC_EVT_TIMING_QUERY:
-		return sprintf(buffer, "query");
+		return sprintf(buffer, "query\n");
 	case ACPI_EC_EVT_TIMING_EVENT:
-		return sprintf(buffer, "event");
+		return sprintf(buffer, "event\n");
 	default:
-		return sprintf(buffer, "invalid");
+		return sprintf(buffer, "invalid\n");
 	}
 	return 0;
 }
diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
index ccd900690b6f..b1a7f8d6965e 100644
--- a/drivers/acpi/evged.c
+++ b/drivers/acpi/evged.c
@@ -106,7 +106,7 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
 
 		if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
 			break;
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index f5525f8bb770..a303f0123394 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -16,7 +16,7 @@
 /* ACPI 6.1 */
 #define UUID_NFIT_BUS "2f10e7a4-9e91-11e4-89d3-123b93f75cba"
 
-/* http://pmem.io/documents/NVDIMM_DSM_Interface-V1.6.pdf */
+/* https://pmem.io/documents/NVDIMM_DSM_Interface-V1.6.pdf */
 #define UUID_NFIT_DIMM "4309ac30-0d11-11e4-9191-0800200c9a66"
 
 /* https://github.com/HewlettPackard/hpe-nvm/blob/master/Documentation/ */
diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 5be5a977da1b..15bbaab8500b 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -230,7 +230,7 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
 		pxm &= 0xff;
 
 	node = acpi_map_pxm_to_node(pxm);
-	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
+	if (node == NUMA_NO_NODE) {
 		pr_err("SRAT: Too many proximity domains.\n");
 		goto out_err_bad_srat;
 	}
@@ -291,8 +291,6 @@ acpi_parse_x2apic_affinity(union acpi_subtable_headers *header,
 	struct acpi_srat_x2apic_cpu_affinity *processor_affinity;
 
 	processor_affinity = (struct acpi_srat_x2apic_cpu_affinity *)header;
-	if (!processor_affinity)
-		return -EINVAL;
 
 	acpi_table_print_srat_entry(&header->common);
 
@@ -309,8 +307,6 @@ acpi_parse_processor_affinity(union acpi_subtable_headers *header,
 	struct acpi_srat_cpu_affinity *processor_affinity;
 
 	processor_affinity = (struct acpi_srat_cpu_affinity *)header;
-	if (!processor_affinity)
-		return -EINVAL;
 
 	acpi_table_print_srat_entry(&header->common);
 
@@ -327,8 +323,6 @@ acpi_parse_gicc_affinity(union acpi_subtable_headers *header,
 	struct acpi_srat_gicc_affinity *processor_affinity;
 
 	processor_affinity = (struct acpi_srat_gicc_affinity *)header;
-	if (!processor_affinity)
-		return -EINVAL;
 
 	acpi_table_print_srat_entry(&header->common);
 
@@ -347,8 +341,6 @@ acpi_parse_memory_affinity(union acpi_subtable_headers * header,
 	struct acpi_srat_mem_affinity *memory_affinity;
 
 	memory_affinity = (struct acpi_srat_mem_affinity *)header;
-	if (!memory_affinity)
-		return -EINVAL;
 
 	acpi_table_print_srat_entry(&header->common);
 
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 762c5d50b8fe..6ad8cb05f672 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -77,7 +77,10 @@ struct acpi_ioremap {
 	void __iomem *virt;
 	acpi_physical_address phys;
 	acpi_size size;
-	unsigned long refcount;
+	union {
+		unsigned long refcount;
+		struct rcu_work rwork;
+	} track;
 };
 
 static LIST_HEAD(acpi_ioremaps);
@@ -250,7 +253,7 @@ void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size)
 	map = acpi_map_lookup(phys, size);
 	if (map) {
 		virt = map->virt + (phys - map->phys);
-		map->refcount++;
+		map->track.refcount++;
 	}
 	mutex_unlock(&acpi_ioremap_lock);
 	return virt;
@@ -335,7 +338,7 @@ void __iomem __ref
 	/* Check if there's a suitable mapping already. */
 	map = acpi_map_lookup(phys, size);
 	if (map) {
-		map->refcount++;
+		map->track.refcount++;
 		goto out;
 	}
 
@@ -358,7 +361,7 @@ void __iomem __ref
 	map->virt = virt;
 	map->phys = pg_off;
 	map->size = pg_sz;
-	map->refcount = 1;
+	map->track.refcount = 1;
 
 	list_add_tail_rcu(&map->list, &acpi_ioremaps);
 
@@ -374,21 +377,26 @@ void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
 }
 EXPORT_SYMBOL_GPL(acpi_os_map_memory);
 
-/* Must be called with mutex_lock(&acpi_ioremap_lock) */
-static unsigned long acpi_os_drop_map_ref(struct acpi_ioremap *map)
+static void acpi_os_map_remove(struct work_struct *work)
 {
-	unsigned long refcount = --map->refcount;
+	struct acpi_ioremap *map = container_of(to_rcu_work(work),
+						struct acpi_ioremap,
+						track.rwork);
 
-	if (!refcount)
-		list_del_rcu(&map->list);
-	return refcount;
+	acpi_unmap(map->phys, map->virt);
+	kfree(map);
 }
 
-static void acpi_os_map_cleanup(struct acpi_ioremap *map)
+/* Must be called with mutex_lock(&acpi_ioremap_lock) */
+static void acpi_os_drop_map_ref(struct acpi_ioremap *map)
 {
-	synchronize_rcu_expedited();
-	acpi_unmap(map->phys, map->virt);
-	kfree(map);
+	if (--map->track.refcount)
+		return;
+
+	list_del_rcu(&map->list);
+
+	INIT_RCU_WORK(&map->track.rwork, acpi_os_map_remove);
+	queue_rcu_work(system_wq, &map->track.rwork);
 }
 
 /**
@@ -397,8 +405,8 @@ static void acpi_os_map_cleanup(struct acpi_ioremap *map)
  * @size: Size of the address range to drop a reference to.
  *
  * Look up the given virtual address range in the list of existing ACPI memory
- * mappings, drop a reference to it and unmap it if there are no more active
- * references to it.
+ * mappings, drop a reference to it and if there are no more active references
+ * to it, queue it up for later removal.
  *
  * During early init (when acpi_permanent_mmap has not been set yet) this
  * routine simply calls __acpi_unmap_table() to get the job done.  Since
@@ -408,7 +416,6 @@ 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);
@@ -416,23 +423,27 @@ void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size)
 	}
 
 	mutex_lock(&acpi_ioremap_lock);
+
 	map = acpi_map_lookup_virt(virt, size);
 	if (!map) {
 		mutex_unlock(&acpi_ioremap_lock);
 		WARN(true, PREFIX "%s: bad address %p\n", __func__, virt);
 		return;
 	}
-	refcount = acpi_os_drop_map_ref(map);
-	mutex_unlock(&acpi_ioremap_lock);
+	acpi_os_drop_map_ref(map);
 
-	if (!refcount)
-		acpi_os_map_cleanup(map);
+	mutex_unlock(&acpi_ioremap_lock);
 }
 EXPORT_SYMBOL_GPL(acpi_os_unmap_iomem);
 
+/**
+ * acpi_os_unmap_memory - Drop a memory mapping reference.
+ * @virt: Start of the address range to drop a reference to.
+ * @size: Size of the address range to drop a reference to.
+ */
 void __ref acpi_os_unmap_memory(void *virt, acpi_size size)
 {
-	return acpi_os_unmap_iomem((void __iomem *)virt, size);
+	acpi_os_unmap_iomem((void __iomem *)virt, size);
 }
 EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
 
@@ -461,7 +472,6 @@ 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;
@@ -472,16 +482,15 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
 		return;
 
 	mutex_lock(&acpi_ioremap_lock);
+
 	map = acpi_map_lookup(addr, gas->bit_width / 8);
 	if (!map) {
 		mutex_unlock(&acpi_ioremap_lock);
 		return;
 	}
-	refcount = acpi_os_drop_map_ref(map);
-	mutex_unlock(&acpi_ioremap_lock);
+	acpi_os_drop_map_ref(map);
 
-	if (!refcount)
-		acpi_os_map_cleanup(map);
+	mutex_unlock(&acpi_ioremap_lock);
 }
 EXPORT_SYMBOL(acpi_os_unmap_generic_address);
 
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 0c65a09aec1b..71a30b0d0f05 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -203,8 +203,7 @@ static void tsc_check_state(int state)
 		 */
 		if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 			return;
-
-		/*FALL THROUGH*/
+		fallthrough;
 	default:
 		/* TSC could halt in idle, so notify users */
 		if (state > ACPI_STATE_C1)
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index e601c4511a8b..6941062272e0 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -606,13 +606,7 @@ static struct fwnode_handle *
 acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
 				 const char *childname)
 {
-	char name[ACPI_PATH_SEGMENT_LENGTH];
 	struct fwnode_handle *child;
-	struct acpi_buffer path;
-	acpi_status status;
-
-	path.length = sizeof(name);
-	path.pointer = name;
 
 	fwnode_for_each_child_node(fwnode, child) {
 		if (is_acpi_data_node(child)) {
@@ -621,12 +615,8 @@ acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
 			continue;
 		}
 
-		status = acpi_get_name(ACPI_HANDLE_FWNODE(child),
-				       ACPI_SINGLE_NAME, &path);
-		if (ACPI_FAILURE(status))
-			break;
-
-		if (!strncmp(name, childname, ACPI_NAMESEG_SIZE))
+		if (!strncmp(acpi_device_bid(to_acpi_device_node(child)),
+			     childname, ACPI_NAMESEG_SIZE))
 			return child;
 	}
 
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 3b4448972374..ad04824ca3ba 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -373,7 +373,7 @@ unsigned int acpi_dev_get_irq_type(int triggering, int polarity)
 	case ACPI_ACTIVE_BOTH:
 		if (triggering == ACPI_EDGE_SENSITIVE)
 			return IRQ_TYPE_EDGE_BOTH;
-		/* fall through */
+		fallthrough;
 	default:
 		return IRQ_TYPE_NONE;
 	}
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index d73b4535e79d..88460bacd5ae 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -111,7 +111,7 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console)
 			table->serial_port.access_width))) {
 		default:
 			pr_err("Unexpected SPCR Access Width.  Defaulting to byte size\n");
-			/* fall through */
+			fallthrough;
 		case 8:
 			iotype = "mmio";
 			break;
@@ -128,7 +128,7 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console)
 	switch (table->interface_type) {
 	case ACPI_DBG2_ARM_SBSA_32BIT:
 		iotype = "mmio32";
-		/* fall through */
+		fallthrough;
 	case ACPI_DBG2_ARM_PL011:
 	case ACPI_DBG2_ARM_SBSA_GENERIC:
 	case ACPI_DBG2_BCM2835:
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 76c668c05fa0..a5cc4f3bb1e3 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -214,7 +214,7 @@ static int param_set_trace_method_name(const char *val,
 
 static int param_get_trace_method_name(char *buffer, const struct kernel_param *kp)
 {
-	return scnprintf(buffer, PAGE_SIZE, "%s", acpi_gbl_trace_method_name);
+	return scnprintf(buffer, PAGE_SIZE, "%s\n", acpi_gbl_trace_method_name);
 }
 
 static const struct kernel_param_ops param_ops_trace_method = {
@@ -271,15 +271,15 @@ static int param_set_trace_state(const char *val,
 static int param_get_trace_state(char *buffer, const struct kernel_param *kp)
 {
 	if (!(acpi_gbl_trace_flags & ACPI_TRACE_ENABLED))
-		return sprintf(buffer, "disable");
+		return sprintf(buffer, "disable\n");
 	else {
 		if (acpi_gbl_trace_method_name) {
 			if (acpi_gbl_trace_flags & ACPI_TRACE_ONESHOT)
-				return sprintf(buffer, "method-once");
+				return sprintf(buffer, "method-once\n");
 			else
-				return sprintf(buffer, "method");
+				return sprintf(buffer, "method\n");
 		} else
-			return sprintf(buffer, "enable");
+			return sprintf(buffer, "enable\n");
 	}
 	return 0;
 }
@@ -302,7 +302,7 @@ static int param_get_acpica_version(char *buffer,
 {
 	int result;
 
-	result = sprintf(buffer, "%x", ACPI_CA_VERSION);
+	result = sprintf(buffer, "%x\n", ACPI_CA_VERSION);
 
 	return result;
 }
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 0e905c3d1645..e48690a006a4 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -292,20 +292,6 @@ static int __init acpi_parse_entries_array(char *id, unsigned long table_size,
 	int errs = 0;
 	int i;
 
-	if (acpi_disabled)
-		return -ENODEV;
-
-	if (!id)
-		return -EINVAL;
-
-	if (!table_size)
-		return -EINVAL;
-
-	if (!table_header) {
-		pr_warn("%4.4s not present\n", id);
-		return -ENODEV;
-	}
-
 	table_end = (unsigned long)table_header + table_header->length;
 
 	/* Parse all entries looking for a match. */
@@ -371,6 +357,9 @@ int __init acpi_table_parse_entries_array(char *id,
 	if (!id)
 		return -EINVAL;
 
+	if (!table_size)
+		return -EINVAL;
+
 	if (!strncmp(id, ACPI_SIG_MADT, 4))
 		instance = acpi_apic_instance;
 
@@ -490,7 +479,7 @@ static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
 }
 
 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
-static const char * const table_sigs[] = {
+static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
 	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
 	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
 	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
@@ -501,7 +490,7 @@ static const char * const table_sigs[] = {
 	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
 	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
 	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
-	ACPI_SIG_NHLT, NULL };
+	ACPI_SIG_NHLT };
 
 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
 
@@ -548,11 +537,11 @@ void __init acpi_table_upgrade(void)
 
 		table = file.data;
 
-		for (sig = 0; table_sigs[sig]; sig++)
+		for (sig = 0; sig < ARRAY_SIZE(table_sigs); sig++)
 			if (!memcmp(table->signature, table_sigs[sig], 4))
 				break;
 
-		if (!table_sigs[sig]) {
+		if (sig >= ARRAY_SIZE(table_sigs)) {
 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
 				cpio_path, file.name);
 			continue;