2 files changed, 210 insertions, 50 deletions

diff --git a/net/rfkill/rfkill-input.h b/net/rfkill/rfkill-input.h
index f63d050..bbfa646 100644
--- a/net/rfkill/rfkill-input.h
+++ b/net/rfkill/rfkill-input.h
@@ -13,5 +13,6 @@
 
 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state);
 void rfkill_epo(void);
+void rfkill_restore_states(void);
 
 #endif /* __RFKILL_INPUT_H */
diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index 74aecc0..f949a48 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -37,14 +37,20 @@ MODULE_DESCRIPTION("RF switch support");
 MODULE_LICENSE("GPL");
 
 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
-static DEFINE_MUTEX(rfkill_mutex);
+static DEFINE_MUTEX(rfkill_global_mutex);
 
 static unsigned int rfkill_default_state = RFKILL_STATE_UNBLOCKED;
 module_param_named(default_state, rfkill_default_state, uint, 0444);
 MODULE_PARM_DESC(default_state,
 		 "Default initial state for all radio types, 0 = radio off");
 
-static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
+struct rfkill_gsw_state {
+	enum rfkill_state current_state;
+	enum rfkill_state default_state;
+};
+
+static struct rfkill_gsw_state rfkill_global_states[RFKILL_TYPE_MAX];
+static unsigned long rfkill_states_lockdflt[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
 
 static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
 
@@ -70,6 +76,7 @@ static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  */
 int register_rfkill_notifier(struct notifier_block *nb)
 {
+	BUG_ON(!nb);
 	return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
@@ -85,6 +92,7 @@ EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  */
 int unregister_rfkill_notifier(struct notifier_block *nb)
 {
+	BUG_ON(!nb);
 	return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
@@ -117,6 +125,7 @@ static void rfkill_led_trigger_activate(struct led_classdev *led)
 
 static void notify_rfkill_state_change(struct rfkill *rfkill)
 {
+	rfkill_led_trigger(rfkill, rfkill->state);
 	blocking_notifier_call_chain(&rfkill_notifier_list,
 			RFKILL_STATE_CHANGED,
 			rfkill);
@@ -195,6 +204,11 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
 		 * BLOCK even a transmitter that is already in state
 		 * RFKILL_STATE_HARD_BLOCKED */
 		break;
+	default:
+		WARN(1, KERN_WARNING
+			"rfkill: illegal state %d passed as parameter "
+			"to rfkill_toggle_radio\n", state);
+		return -EINVAL;
 	}
 
 	if (force || state != rfkill->state) {
@@ -204,31 +218,36 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
 			rfkill->state = state;
 	}
 
-	if (force || rfkill->state != oldstate) {
-		rfkill_led_trigger(rfkill, rfkill->state);
+	if (force || rfkill->state != oldstate)
 		notify_rfkill_state_change(rfkill);
-	}
 
 	return retval;
 }
 
 /**
- * rfkill_switch_all - Toggle state of all switches of given type
+ * __rfkill_switch_all - Toggle state of all switches of given type
  * @type: type of interfaces to be affected
  * @state: the new state
  *
  * This function toggles the state of all switches of given type,
  * unless a specific switch is claimed by userspace (in which case,
  * that switch is left alone) or suspended.
+ *
+ * Caller must have acquired rfkill_global_mutex.
  */
-void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
+static void __rfkill_switch_all(const enum rfkill_type type,
+				const enum rfkill_state state)
 {
 	struct rfkill *rfkill;
 
-	mutex_lock(&rfkill_mutex);
-
-	rfkill_states[type] = state;
+	if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
+			KERN_WARNING
+			"rfkill: illegal state %d or type %d "
+			"passed as parameter to __rfkill_switch_all\n",
+			state, type))
+		return;
 
+	rfkill_global_states[type].current_state = state;
 	list_for_each_entry(rfkill, &rfkill_list, node) {
 		if ((!rfkill->user_claim) && (rfkill->type == type)) {
 			mutex_lock(&rfkill->mutex);
@@ -236,8 +255,21 @@ void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 			mutex_unlock(&rfkill->mutex);
 		}
 	}
+}
 
-	mutex_unlock(&rfkill_mutex);
+/**
+ * rfkill_switch_all - Toggle state of all switches of given type
+ * @type: type of interfaces to be affected
+ * @state: the new state
+ *
+ * Acquires rfkill_global_mutex and calls __rfkill_switch_all(@type, @state).
+ * Please refer to __rfkill_switch_all() for details.
+ */
+void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
+{
+	mutex_lock(&rfkill_global_mutex);
+	__rfkill_switch_all(type, state);
+	mutex_unlock(&rfkill_global_mutex);
 }
 EXPORT_SYMBOL(rfkill_switch_all);
 
@@ -245,23 +277,53 @@ EXPORT_SYMBOL(rfkill_switch_all);
  * rfkill_epo - emergency power off all transmitters
  *
  * This kicks all non-suspended rfkill devices to RFKILL_STATE_SOFT_BLOCKED,
- * ignoring everything in its path but rfkill_mutex and rfkill->mutex.
+ * ignoring everything in its path but rfkill_global_mutex and rfkill->mutex.
+ *
+ * The global state before the EPO is saved and can be restored later
+ * using rfkill_restore_states().
  */
 void rfkill_epo(void)
 {
 	struct rfkill *rfkill;
+	int i;
+
+	mutex_lock(&rfkill_global_mutex);
 
-	mutex_lock(&rfkill_mutex);
 	list_for_each_entry(rfkill, &rfkill_list, node) {
 		mutex_lock(&rfkill->mutex);
 		rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 		mutex_unlock(&rfkill->mutex);
 	}
-	mutex_unlock(&rfkill_mutex);
+	for (i = 0; i < RFKILL_TYPE_MAX; i++) {
+		rfkill_global_states[i].default_state =
+				rfkill_global_states[i].current_state;
+		rfkill_global_states[i].current_state =
+				RFKILL_STATE_SOFT_BLOCKED;
+	}
+	mutex_unlock(&rfkill_global_mutex);
 }
 EXPORT_SYMBOL_GPL(rfkill_epo);
 
 /**
+ * rfkill_restore_states - restore global states
+ *
+ * Restore (and sync switches to) the global state from the
+ * states in rfkill_default_states.  This can undo the effects of
+ * a call to rfkill_epo().
+ */
+void rfkill_restore_states(void)
+{
+	int i;
+
+	mutex_lock(&rfkill_global_mutex);
+
+	for (i = 0; i < RFKILL_TYPE_MAX; i++)
+		__rfkill_switch_all(i, rfkill_global_states[i].default_state);
+	mutex_unlock(&rfkill_global_mutex);
+}
+EXPORT_SYMBOL_GPL(rfkill_restore_states);
+
+/**
  * rfkill_force_state - Force the internal rfkill radio state
  * @rfkill: pointer to the rfkill class to modify.
  * @state: the current radio state the class should be forced to.
@@ -282,9 +344,11 @@ int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 {
 	enum rfkill_state oldstate;
 
-	if (state != RFKILL_STATE_SOFT_BLOCKED &&
-	    state != RFKILL_STATE_UNBLOCKED &&
-	    state != RFKILL_STATE_HARD_BLOCKED)
+	BUG_ON(!rfkill);
+	if (WARN((state >= RFKILL_STATE_MAX),
+			KERN_WARNING
+			"rfkill: illegal state %d passed as parameter "
+			"to rfkill_force_state\n", state))
 		return -EINVAL;
 
 	mutex_lock(&rfkill->mutex);
@@ -352,12 +416,16 @@ static ssize_t rfkill_state_store(struct device *dev,
 				  const char *buf, size_t count)
 {
 	struct rfkill *rfkill = to_rfkill(dev);
-	unsigned int state = simple_strtoul(buf, NULL, 0);
+	unsigned long state;
 	int error;
 
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
+	error = strict_strtoul(buf, 0, &state);
+	if (error)
+		return error;
+
 	/* RFKILL_STATE_HARD_BLOCKED is illegal here... */
 	if (state != RFKILL_STATE_UNBLOCKED &&
 	    state != RFKILL_STATE_SOFT_BLOCKED)
@@ -385,7 +453,8 @@ static ssize_t rfkill_claim_store(struct device *dev,
 				  const char *buf, size_t count)
 {
 	struct rfkill *rfkill = to_rfkill(dev);
-	bool claim = !!simple_strtoul(buf, NULL, 0);
+	unsigned long claim_tmp;
+	bool claim;
 	int error;
 
 	if (!capable(CAP_NET_ADMIN))
@@ -394,11 +463,16 @@ static ssize_t rfkill_claim_store(struct device *dev,
 	if (rfkill->user_claim_unsupported)
 		return -EOPNOTSUPP;
 
+	error = strict_strtoul(buf, 0, &claim_tmp);
+	if (error)
+		return error;
+	claim = !!claim_tmp;
+
 	/*
 	 * Take the global lock to make sure the kernel is not in
 	 * the middle of rfkill_switch_all
 	 */
-	error = mutex_lock_interruptible(&rfkill_mutex);
+	error = mutex_lock_interruptible(&rfkill_global_mutex);
 	if (error)
 		return error;
 
@@ -406,14 +480,14 @@ static ssize_t rfkill_claim_store(struct device *dev,
 		if (!claim) {
 			mutex_lock(&rfkill->mutex);
 			rfkill_toggle_radio(rfkill,
-					    rfkill_states[rfkill->type],
-					    0);
+					rfkill_global_states[rfkill->type].current_state,
+					0);
 			mutex_unlock(&rfkill->mutex);
 		}
 		rfkill->user_claim = claim;
 	}
 
-	mutex_unlock(&rfkill_mutex);
+	mutex_unlock(&rfkill_global_mutex);
 
 	return error ? error : count;
 }
@@ -437,21 +511,9 @@ static void rfkill_release(struct device *dev)
 #ifdef CONFIG_PM
 static int rfkill_suspend(struct device *dev, pm_message_t state)
 {
-	struct rfkill *rfkill = to_rfkill(dev);
-
-	if (dev->power.power_state.event != state.event) {
-		if (state.event & PM_EVENT_SLEEP) {
-			/* Stop transmitter, keep state, no notifies */
-			update_rfkill_state(rfkill);
-
-			mutex_lock(&rfkill->mutex);
-			rfkill->toggle_radio(rfkill->data,
-						RFKILL_STATE_SOFT_BLOCKED);
-			mutex_unlock(&rfkill->mutex);
-		}
-
+	/* mark class device as suspended */
+	if (dev->power.power_state.event != state.event)
 		dev->power.power_state = state;
-	}
 
 	return 0;
 }
@@ -525,24 +587,60 @@ static struct class rfkill_class = {
 	.dev_uevent	= rfkill_dev_uevent,
 };
 
+static int rfkill_check_duplicity(const struct rfkill *rfkill)
+{
+	struct rfkill *p;
+	unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
+
+	memset(seen, 0, sizeof(seen));
+
+	list_for_each_entry(p, &rfkill_list, node) {
+		if (WARN((p == rfkill), KERN_WARNING
+				"rfkill: illegal attempt to register "
+				"an already registered rfkill struct\n"))
+			return -EEXIST;
+		set_bit(p->type, seen);
+	}
+
+	/* 0: first switch of its kind */
+	return test_bit(rfkill->type, seen);
+}
+
 static int rfkill_add_switch(struct rfkill *rfkill)
 {
-	mutex_lock(&rfkill_mutex);
+	int error;
+
+	mutex_lock(&rfkill_global_mutex);
 
-	rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
+	error = rfkill_check_duplicity(rfkill);
+	if (error < 0)
+		goto unlock_out;
+
+	if (!error) {
+		/* lock default after first use */
+		set_bit(rfkill->type, rfkill_states_lockdflt);
+		rfkill_global_states[rfkill->type].current_state =
+			rfkill_global_states[rfkill->type].default_state;
+	}
+
+	rfkill_toggle_radio(rfkill,
+			    rfkill_global_states[rfkill->type].current_state,
+			    0);
 
 	list_add_tail(&rfkill->node, &rfkill_list);
 
-	mutex_unlock(&rfkill_mutex);
+	error = 0;
+unlock_out:
+	mutex_unlock(&rfkill_global_mutex);
 
-	return 0;
+	return error;
 }
 
 static void rfkill_remove_switch(struct rfkill *rfkill)
 {
-	mutex_lock(&rfkill_mutex);
+	mutex_lock(&rfkill_global_mutex);
 	list_del_init(&rfkill->node);
-	mutex_unlock(&rfkill_mutex);
+	mutex_unlock(&rfkill_global_mutex);
 
 	mutex_lock(&rfkill->mutex);
 	rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
@@ -562,11 +660,18 @@ static void rfkill_remove_switch(struct rfkill *rfkill)
  * NOTE: If registration fails the structure shoudl be freed by calling
  * rfkill_free() otherwise rfkill_unregister() should be used.
  */
-struct rfkill *rfkill_allocate(struct device *parent, enum rfkill_type type)
+struct rfkill * __must_check rfkill_allocate(struct device *parent,
+					     enum rfkill_type type)
 {
 	struct rfkill *rfkill;
 	struct device *dev;
 
+	if (WARN((type >= RFKILL_TYPE_MAX),
+			KERN_WARNING
+			"rfkill: illegal type %d passed as parameter "
+			"to rfkill_allocate\n", type))
+		return NULL;
+
 	rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
 	if (!rfkill)
 		return NULL;
@@ -633,15 +738,18 @@ static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
  * structure needs to be registered. Immediately from registration the
  * switch driver should be able to service calls to toggle_radio.
  */
-int rfkill_register(struct rfkill *rfkill)
+int __must_check rfkill_register(struct rfkill *rfkill)
 {
 	static atomic_t rfkill_no = ATOMIC_INIT(0);
 	struct device *dev = &rfkill->dev;
 	int error;
 
-	if (!rfkill->toggle_radio)
-		return -EINVAL;
-	if (rfkill->type >= RFKILL_TYPE_MAX)
+	if (WARN((!rfkill || !rfkill->toggle_radio ||
+			rfkill->type >= RFKILL_TYPE_MAX ||
+			rfkill->state >= RFKILL_STATE_MAX),
+			KERN_WARNING
+			"rfkill: attempt to register a "
+			"badly initialized rfkill struct\n"))
 		return -EINVAL;
 
 	snprintf(dev->bus_id, sizeof(dev->bus_id),
@@ -676,6 +784,7 @@ EXPORT_SYMBOL(rfkill_register);
  */
 void rfkill_unregister(struct rfkill *rfkill)
 {
+	BUG_ON(!rfkill);
 	device_del(&rfkill->dev);
 	rfkill_remove_switch(rfkill);
 	rfkill_led_trigger_unregister(rfkill);
@@ -683,6 +792,56 @@ void rfkill_unregister(struct rfkill *rfkill)
 }
 EXPORT_SYMBOL(rfkill_unregister);
 
+/**
+ * rfkill_set_default - set initial value for a switch type
+ * @type - the type of switch to set the default state of
+ * @state - the new default state for that group of switches
+ *
+ * Sets the initial state rfkill should use for a given type.
+ * The following initial states are allowed: RFKILL_STATE_SOFT_BLOCKED
+ * and RFKILL_STATE_UNBLOCKED.
+ *
+ * This function is meant to be used by platform drivers for platforms
+ * that can save switch state across power down/reboot.
+ *
+ * The default state for each switch type can be changed exactly once.
+ * After a switch of that type is registered, the default state cannot
+ * be changed anymore.  This guards against multiple drivers it the
+ * same platform trying to set the initial switch default state, which
+ * is not allowed.
+ *
+ * Returns -EPERM if the state has already been set once or is in use,
+ * so drivers likely want to either ignore or at most printk(KERN_NOTICE)
+ * if this function returns -EPERM.
+ *
+ * Returns 0 if the new default state was set, or an error if it
+ * could not be set.
+ */
+int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
+{
+	int error;
+
+	if (WARN((type >= RFKILL_TYPE_MAX ||
+			(state != RFKILL_STATE_SOFT_BLOCKED &&
+			 state != RFKILL_STATE_UNBLOCKED)),
+			KERN_WARNING
+			"rfkill: illegal state %d or type %d passed as "
+			"parameter to rfkill_set_default\n", state, type))
+		return -EINVAL;
+
+	mutex_lock(&rfkill_global_mutex);
+
+	if (!test_and_set_bit(type, rfkill_states_lockdflt)) {
+		rfkill_global_states[type].default_state = state;
+		error = 0;
+	} else
+		error = -EPERM;
+
+	mutex_unlock(&rfkill_global_mutex);
+	return error;
+}
+EXPORT_SYMBOL_GPL(rfkill_set_default);
+
 /*
  * Rfkill module initialization/deinitialization.
  */
@@ -696,8 +855,8 @@ static int __init rfkill_init(void)
 	    rfkill_default_state != RFKILL_STATE_UNBLOCKED)
 		return -EINVAL;
 
-	for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
-		rfkill_states[i] = rfkill_default_state;
+	for (i = 0; i < RFKILL_TYPE_MAX; i++)
+		rfkill_global_states[i].default_state = rfkill_default_state;
 
 	error = class_register(&rfkill_class);
 	if (error) {