7 files changed, 162 insertions, 74 deletions

diff --git a/drivers/acpi/acpi_pnp.c b/drivers/acpi/acpi_pnp.c
index c58940b..48fc3ad 100644
--- a/drivers/acpi/acpi_pnp.c
+++ b/drivers/acpi/acpi_pnp.c
@@ -316,7 +316,7 @@ static const struct acpi_device_id acpi_pnp_device_ids[] = {
 	{""},
 };
 
-static bool matching_id(char *idstr, char *list_id)
+static bool matching_id(const char *idstr, const char *list_id)
 {
 	int i;
 
@@ -333,7 +333,7 @@ static bool matching_id(char *idstr, char *list_id)
 	return true;
 }
 
-static bool acpi_pnp_match(char *idstr, const struct acpi_device_id **matchid)
+static bool acpi_pnp_match(const char *idstr, const struct acpi_device_id **matchid)
 {
 	const struct acpi_device_id *devid;
 
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 42c66b6..f61a7c8 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -441,17 +441,31 @@ static void acpi_ec_complete_query(struct acpi_ec *ec)
 
 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 {
+	bool guarded = true;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ec->lock, flags);
+	/*
+	 * If firmware SCI_EVT clearing timing is "event", we actually
+	 * don't know when the SCI_EVT will be cleared by firmware after
+	 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
+	 * acceptable period.
+	 *
+	 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
+	 * flagged, which means SCI_EVT check has just been performed.
+	 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
+	 * guarding should have already been performed (via
+	 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
+	 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
+	 * ACPI_EC_COMMAND_POLL state immediately.
+	 */
 	if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 	    ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 	    !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 	    (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
-		return false;
-
-	/*
-	 * Postpone the query submission to allow the firmware to proceed,
-	 * we shouldn't check SCI_EVT before the firmware reflagging it.
-	 */
-	return true;
+		guarded = false;
+	spin_unlock_irqrestore(&ec->lock, flags);
+	return guarded;
 }
 
 static int ec_transaction_polled(struct acpi_ec *ec)
@@ -597,6 +611,7 @@ static int ec_guard(struct acpi_ec *ec)
 	unsigned long guard = usecs_to_jiffies(ec_polling_guard);
 	unsigned long timeout = ec->timestamp + guard;
 
+	/* Ensure guarding period before polling EC status */
 	do {
 		if (ec_busy_polling) {
 			/* Perform busy polling */
@@ -606,11 +621,13 @@ static int ec_guard(struct acpi_ec *ec)
 		} else {
 			/*
 			 * Perform wait polling
-			 *
-			 * For SCI_EVT clearing timing of "event",
-			 * performing guarding before re-checking the
-			 * SCI_EVT. Otherwise, such guarding is not needed
-			 * due to the old practices.
+			 * 1. Wait the transaction to be completed by the
+			 *    GPE handler after the transaction enters
+			 *    ACPI_EC_COMMAND_POLL state.
+			 * 2. A special guarding logic is also required
+			 *    for event clearing mode "event" before the
+			 *    transaction enters ACPI_EC_COMMAND_POLL
+			 *    state.
 			 */
 			if (!ec_transaction_polled(ec) &&
 			    !acpi_ec_guard_event(ec))
@@ -620,7 +637,6 @@ static int ec_guard(struct acpi_ec *ec)
 					       guard))
 				return 0;
 		}
-		/* Guard the register accesses for the polling modes */
 	} while (time_before(jiffies, timeout));
 	return -ETIME;
 }
@@ -929,6 +945,23 @@ acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 	return handler;
 }
 
+static struct acpi_ec_query_handler *
+acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
+{
+	struct acpi_ec_query_handler *handler;
+	bool found = false;
+
+	mutex_lock(&ec->mutex);
+	list_for_each_entry(handler, &ec->list, node) {
+		if (value == handler->query_bit) {
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&ec->mutex);
+	return found ? acpi_ec_get_query_handler(handler) : NULL;
+}
+
 static void acpi_ec_query_handler_release(struct kref *kref)
 {
 	struct acpi_ec_query_handler *handler =
@@ -964,14 +997,15 @@ int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 }
 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 
-void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
+static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
+					  bool remove_all, u8 query_bit)
 {
 	struct acpi_ec_query_handler *handler, *tmp;
 	LIST_HEAD(free_list);
 
 	mutex_lock(&ec->mutex);
 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
-		if (query_bit == handler->query_bit) {
+		if (remove_all || query_bit == handler->query_bit) {
 			list_del_init(&handler->node);
 			list_add(&handler->node, &free_list);
 		}
@@ -980,6 +1014,11 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 	list_for_each_entry_safe(handler, tmp, &free_list, node)
 		acpi_ec_put_query_handler(handler);
 }
+
+void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
+{
+	acpi_ec_remove_query_handlers(ec, false, query_bit);
+}
 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 
 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
@@ -1025,7 +1064,6 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 {
 	u8 value = 0;
 	int result;
-	struct acpi_ec_query_handler *handler;
 	struct acpi_ec_query *q;
 
 	q = acpi_ec_create_query(&value);
@@ -1043,25 +1081,26 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 	if (result)
 		goto err_exit;
 
-	mutex_lock(&ec->mutex);
-	result = -ENODATA;
-	list_for_each_entry(handler, &ec->list, node) {
-		if (value == handler->query_bit) {
-			result = 0;
-			q->handler = acpi_ec_get_query_handler(handler);
-			ec_dbg_evt("Query(0x%02x) scheduled",
-				   q->handler->query_bit);
-			/*
-			 * It is reported that _Qxx are evaluated in a
-			 * parallel way on Windows:
-			 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
-			 */
-			if (!schedule_work(&q->work))
-				result = -EBUSY;
-			break;
-		}
+	q->handler = acpi_ec_get_query_handler_by_value(ec, value);
+	if (!q->handler) {
+		result = -ENODATA;
+		goto err_exit;
+	}
+
+	/*
+	 * It is reported that _Qxx are evaluated in a parallel way on
+	 * Windows:
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
+	 *
+	 * Put this log entry before schedule_work() in order to make
+	 * it appearing before any other log entries occurred during the
+	 * work queue execution.
+	 */
+	ec_dbg_evt("Query(0x%02x) scheduled", value);
+	if (!schedule_work(&q->work)) {
+		ec_dbg_evt("Query(0x%02x) overlapped", value);
+		result = -EBUSY;
 	}
-	mutex_unlock(&ec->mutex);
 
 err_exit:
 	if (result && q)
@@ -1354,19 +1393,13 @@ static int acpi_ec_add(struct acpi_device *device)
 static int acpi_ec_remove(struct acpi_device *device)
 {
 	struct acpi_ec *ec;
-	struct acpi_ec_query_handler *handler, *tmp;
 
 	if (!device)
 		return -EINVAL;
 
 	ec = acpi_driver_data(device);
 	ec_remove_handlers(ec);
-	mutex_lock(&ec->mutex);
-	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
-		list_del(&handler->node);
-		kfree(handler);
-	}
-	mutex_unlock(&ec->mutex);
+	acpi_ec_remove_query_handlers(ec, true, 0);
 	release_region(ec->data_addr, 1);
 	release_region(ec->command_addr, 1);
 	device->driver_data = NULL;
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index b9657af..1470ae4 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -351,13 +351,12 @@ static int acpi_platform_notify_remove(struct device *dev)
 	return 0;
 }
 
-int __init init_acpi_device_notify(void)
+void __init init_acpi_device_notify(void)
 {
 	if (platform_notify || platform_notify_remove) {
 		printk(KERN_ERR PREFIX "Can't use platform_notify\n");
-		return 0;
+		return;
 	}
 	platform_notify = acpi_platform_notify;
 	platform_notify_remove = acpi_platform_notify_remove;
-	return 0;
 }
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 9e42621..c31787b 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -21,7 +21,7 @@
 #define PREFIX "ACPI: "
 
 acpi_status acpi_os_initialize1(void);
-int init_acpi_device_notify(void);
+void init_acpi_device_notify(void);
 int acpi_scan_init(void);
 void acpi_pci_root_init(void);
 void acpi_pci_link_init(void);
@@ -179,13 +179,13 @@ static inline int acpi_sleep_init(void) { return -ENXIO; }
 #endif
 
 #ifdef CONFIG_ACPI_SLEEP
-int acpi_sleep_proc_init(void);
+void acpi_sleep_proc_init(void);
 int suspend_nvs_alloc(void);
 void suspend_nvs_free(void);
 int suspend_nvs_save(void);
 void suspend_nvs_restore(void);
 #else
-static inline int acpi_sleep_proc_init(void) { return 0; }
+static inline void acpi_sleep_proc_init(void) {}
 static inline int suspend_nvs_alloc(void) { return 0; }
 static inline void suspend_nvs_free(void) {}
 static inline int suspend_nvs_save(void) { return 0; }
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
index 75c28ea..2a35815 100644
--- a/drivers/acpi/proc.c
+++ b/drivers/acpi/proc.c
@@ -144,11 +144,9 @@ static const struct file_operations acpi_system_wakeup_device_fops = {
 	.release = single_release,
 };
 
-int __init acpi_sleep_proc_init(void)
+void __init acpi_sleep_proc_init(void)
 {
 	/* 'wakeup device' [R/W] */
 	proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
 		    acpi_root_dir, &acpi_system_wakeup_device_fops);
-
-	return 0;
 }
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index d1ce377..f834b8c 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1164,7 +1164,7 @@ static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
 	if (!id)
 		return;
 
-	id->id = kstrdup(dev_id, GFP_KERNEL);
+	id->id = kstrdup_const(dev_id, GFP_KERNEL);
 	if (!id->id) {
 		kfree(id);
 		return;
@@ -1302,7 +1302,7 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
 	struct acpi_hardware_id *id, *tmp;
 
 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
-		kfree(id->id);
+		kfree_const(id->id);
 		kfree(id);
 	}
 	kfree(pnp->unique_id);
@@ -1452,7 +1452,7 @@ bool acpi_device_is_present(struct acpi_device *adev)
 }
 
 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
-				       char *idstr,
+				       const char *idstr,
 				       const struct acpi_device_id **matchid)
 {
 	const struct acpi_device_id *devid;
@@ -1471,7 +1471,7 @@ static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
 	return false;
 }
 
-static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
+static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
 					const struct acpi_device_id **matchid)
 {
 	struct acpi_scan_handler *handler;
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 17a6fa0..6c0f079 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -210,20 +210,39 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
 	}
 }
 
-int __init
-acpi_parse_entries(char *id, unsigned long table_size,
-		acpi_tbl_entry_handler handler,
+/**
+ * acpi_parse_entries_array - for each proc_num find a suitable subtable
+ *
+ * @id: table id (for debugging purposes)
+ * @table_size: single entry size
+ * @table_header: where does the table start?
+ * @proc: array of acpi_subtable_proc struct containing entry id
+ *        and associated handler with it
+ * @proc_num: how big proc is?
+ * @max_entries: how many entries can we process?
+ *
+ * For each proc_num find a subtable with proc->id and run proc->handler
+ * on it. Assumption is that there's only single handler for particular
+ * entry id.
+ *
+ * On success returns sum of all matching entries for all proc handlers.
+ * Otherwise, -ENODEV or -EINVAL is returned.
+ */
+static int __init
+acpi_parse_entries_array(char *id, unsigned long table_size,
 		struct acpi_table_header *table_header,
-		int entry_id, unsigned int max_entries)
+		struct acpi_subtable_proc *proc, int proc_num,
+		unsigned int max_entries)
 {
 	struct acpi_subtable_header *entry;
-	int count = 0;
 	unsigned long table_end;
+	int count = 0;
+	int i;
 
 	if (acpi_disabled)
 		return -ENODEV;
 
-	if (!id || !handler)
+	if (!id)
 		return -EINVAL;
 
 	if (!table_size)
@@ -243,20 +262,28 @@ acpi_parse_entries(char *id, unsigned long table_size,
 
 	while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
 	       table_end) {
-		if (entry->type == entry_id
-		    && (!max_entries || count < max_entries)) {
-			if (handler(entry, table_end))
+		if (max_entries && count >= max_entries)
+			break;
+
+		for (i = 0; i < proc_num; i++) {
+			if (entry->type != proc[i].id)
+				continue;
+			if (!proc[i].handler ||
+			     proc[i].handler(entry, table_end))
 				return -EINVAL;
 
-			count++;
+			proc->count++;
+			break;
 		}
+		if (i != proc_num)
+			count++;
 
 		/*
 		 * If entry->length is 0, break from this loop to avoid
 		 * infinite loop.
 		 */
 		if (entry->length == 0) {
-			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
+			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
 			return -EINVAL;
 		}
 
@@ -266,17 +293,32 @@ acpi_parse_entries(char *id, unsigned long table_size,
 
 	if (max_entries && count > max_entries) {
 		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
-			id, entry_id, count - max_entries, count);
+			id, proc->id, count - max_entries, count);
 	}
 
 	return count;
 }
 
 int __init
-acpi_table_parse_entries(char *id,
+acpi_parse_entries(char *id,
+			unsigned long table_size,
+			acpi_tbl_entry_handler handler,
+			struct acpi_table_header *table_header,
+			int entry_id, unsigned int max_entries)
+{
+	struct acpi_subtable_proc proc = {
+		.id		= entry_id,
+		.handler	= handler,
+	};
+
+	return acpi_parse_entries_array(id, table_size, table_header,
+			&proc, 1, max_entries);
+}
+
+int __init
+acpi_table_parse_entries_array(char *id,
 			 unsigned long table_size,
-			 int entry_id,
-			 acpi_tbl_entry_handler handler,
+			 struct acpi_subtable_proc *proc, int proc_num,
 			 unsigned int max_entries)
 {
 	struct acpi_table_header *table_header = NULL;
@@ -287,7 +329,7 @@ acpi_table_parse_entries(char *id,
 	if (acpi_disabled)
 		return -ENODEV;
 
-	if (!id || !handler)
+	if (!id)
 		return -EINVAL;
 
 	if (!strncmp(id, ACPI_SIG_MADT, 4))
@@ -299,14 +341,30 @@ acpi_table_parse_entries(char *id,
 		return -ENODEV;
 	}
 
-	count = acpi_parse_entries(id, table_size, handler, table_header,
-			entry_id, max_entries);
+	count = acpi_parse_entries_array(id, table_size, table_header,
+			proc, proc_num, max_entries);
 
 	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
 	return count;
 }
 
 int __init
+acpi_table_parse_entries(char *id,
+			unsigned long table_size,
+			int entry_id,
+			acpi_tbl_entry_handler handler,
+			unsigned int max_entries)
+{
+	struct acpi_subtable_proc proc = {
+		.id		= entry_id,
+		.handler	= handler,
+	};
+
+	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
+						max_entries);
+}
+
+int __init
 acpi_table_parse_madt(enum acpi_madt_type id,
 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
 {