rfkill: rewrite

This patch completely rewrites the rfkill core to address
the following deficiencies:

 * all rfkill drivers need to implement polling where necessary
   rather than having one central implementation

 * updating the rfkill state cannot be done from arbitrary
   contexts, forcing drivers to use schedule_work and requiring
   lots of code

 * rfkill drivers need to keep track of soft/hard blocked
   internally -- the core should do this

 * the rfkill API has many unexpected quirks, for example being
   asymmetric wrt. alloc/free and register/unregister

 * rfkill can call back into a driver from within a function the
   driver called -- this is prone to deadlocks and generally
   should be avoided

 * rfkill-input pointlessly is a separate module

 * drivers need to #ifdef rfkill functions (unless they want to
   depend on or select RFKILL) -- rfkill should provide inlines
   that do nothing if it isn't compiled in

 * the rfkill structure is not opaque -- drivers need to initialise
   it correctly (lots of sanity checking code required) -- instead
   force drivers to pass the right variables to rfkill_alloc()

 * the documentation is hard to read because it always assumes the
   reader is completely clueless and contains way TOO MANY CAPS

 * the rfkill code needlessly uses a lot of locks and atomic
   operations in locked sections

 * fix LED trigger to actually change the LED when the radio state
   changes -- this wasn't done before

Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 0 insertions, 390 deletions

diff --git a/net/rfkill/rfkill-input.c b/net/rfkill/rfkill-input.c
deleted file mode 100644
index 60a34f3b5f6..00000000000
--- a/net/rfkill/rfkill-input.c
+++ /dev/null
@@ -1,390 +0,0 @@
-/*
- * Input layer to RF Kill interface connector
- *
- * Copyright (c) 2007 Dmitry Torokhov
- */
-
-/*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- */
-
-#include <linux/module.h>
-#include <linux/input.h>
-#include <linux/slab.h>
-#include <linux/workqueue.h>
-#include <linux/init.h>
-#include <linux/rfkill.h>
-#include <linux/sched.h>
-
-#include "rfkill-input.h"
-
-MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
-MODULE_DESCRIPTION("Input layer to RF switch connector");
-MODULE_LICENSE("GPL");
-
-enum rfkill_input_master_mode {
-	RFKILL_INPUT_MASTER_DONOTHING = 0,
-	RFKILL_INPUT_MASTER_RESTORE = 1,
-	RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
-	RFKILL_INPUT_MASTER_MAX,	/* marker */
-};
-
-/* Delay (in ms) between consecutive switch ops */
-#define RFKILL_OPS_DELAY 200
-
-static enum rfkill_input_master_mode rfkill_master_switch_mode =
-					RFKILL_INPUT_MASTER_UNBLOCKALL;
-module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
-MODULE_PARM_DESC(master_switch_mode,
-	"SW_RFKILL_ALL ON should: 0=do nothing; 1=restore; 2=unblock all");
-
-enum rfkill_global_sched_op {
-	RFKILL_GLOBAL_OP_EPO = 0,
-	RFKILL_GLOBAL_OP_RESTORE,
-	RFKILL_GLOBAL_OP_UNLOCK,
-	RFKILL_GLOBAL_OP_UNBLOCK,
-};
-
-struct rfkill_task {
-	struct delayed_work dwork;
-
-	/* ensures that task is serialized */
-	struct mutex mutex;
-
-	/* protects everything below */
-	spinlock_t lock;
-
-	/* pending regular switch operations (1=pending) */
-	unsigned long sw_pending[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
-
-	/* should the state be complemented (1=yes) */
-	unsigned long sw_togglestate[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
-
-	bool global_op_pending;
-	enum rfkill_global_sched_op op;
-
-	/* last time it was scheduled */
-	unsigned long last_scheduled;
-};
-
-static void __rfkill_handle_global_op(enum rfkill_global_sched_op op)
-{
-	unsigned int i;
-
-	switch (op) {
-	case RFKILL_GLOBAL_OP_EPO:
-		rfkill_epo();
-		break;
-	case RFKILL_GLOBAL_OP_RESTORE:
-		rfkill_restore_states();
-		break;
-	case RFKILL_GLOBAL_OP_UNLOCK:
-		rfkill_remove_epo_lock();
-		break;
-	case RFKILL_GLOBAL_OP_UNBLOCK:
-		rfkill_remove_epo_lock();
-		for (i = 0; i < RFKILL_TYPE_MAX; i++)
-			rfkill_switch_all(i, RFKILL_STATE_UNBLOCKED);
-		break;
-	default:
-		/* memory corruption or bug, fail safely */
-		rfkill_epo();
-		WARN(1, "Unknown requested operation %d! "
-			"rfkill Emergency Power Off activated\n",
-			op);
-	}
-}
-
-static void __rfkill_handle_normal_op(const enum rfkill_type type,
-			const bool c)
-{
-	enum rfkill_state state;
-
-	state = rfkill_get_global_state(type);
-	if (c)
-		state = rfkill_state_complement(state);
-
-	rfkill_switch_all(type, state);
-}
-
-static void rfkill_task_handler(struct work_struct *work)
-{
-	struct rfkill_task *task = container_of(work,
-					struct rfkill_task, dwork.work);
-	bool doit = true;
-
-	mutex_lock(&task->mutex);
-
-	spin_lock_irq(&task->lock);
-	while (doit) {
-		if (task->global_op_pending) {
-			enum rfkill_global_sched_op op = task->op;
-			task->global_op_pending = false;
-			memset(task->sw_pending, 0, sizeof(task->sw_pending));
-			spin_unlock_irq(&task->lock);
-
-			__rfkill_handle_global_op(op);
-
-			/* make sure we do at least one pass with
-			 * !task->global_op_pending */
-			spin_lock_irq(&task->lock);
-			continue;
-		} else if (!rfkill_is_epo_lock_active()) {
-			unsigned int i = 0;
-
-			while (!task->global_op_pending &&
-						i < RFKILL_TYPE_MAX) {
-				if (test_and_clear_bit(i, task->sw_pending)) {
-					bool c;
-					c = test_and_clear_bit(i,
-							task->sw_togglestate);
-					spin_unlock_irq(&task->lock);
-
-					__rfkill_handle_normal_op(i, c);
-
-					spin_lock_irq(&task->lock);
-				}
-				i++;
-			}
-		}
-		doit = task->global_op_pending;
-	}
-	spin_unlock_irq(&task->lock);
-
-	mutex_unlock(&task->mutex);
-}
-
-static struct rfkill_task rfkill_task = {
-	.dwork = __DELAYED_WORK_INITIALIZER(rfkill_task.dwork,
-				rfkill_task_handler),
-	.mutex = __MUTEX_INITIALIZER(rfkill_task.mutex),
-	.lock = __SPIN_LOCK_UNLOCKED(rfkill_task.lock),
-};
-
-static unsigned long rfkill_ratelimit(const unsigned long last)
-{
-	const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
-	return (time_after(jiffies, last + delay)) ? 0 : delay;
-}
-
-static void rfkill_schedule_ratelimited(void)
-{
-	if (!delayed_work_pending(&rfkill_task.dwork)) {
-		schedule_delayed_work(&rfkill_task.dwork,
-				rfkill_ratelimit(rfkill_task.last_scheduled));
-		rfkill_task.last_scheduled = jiffies;
-	}
-}
-
-static void rfkill_schedule_global_op(enum rfkill_global_sched_op op)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&rfkill_task.lock, flags);
-	rfkill_task.op = op;
-	rfkill_task.global_op_pending = true;
-	if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
-		/* bypass the limiter for EPO */
-		cancel_delayed_work(&rfkill_task.dwork);
-		schedule_delayed_work(&rfkill_task.dwork, 0);
-		rfkill_task.last_scheduled = jiffies;
-	} else
-		rfkill_schedule_ratelimited();
-	spin_unlock_irqrestore(&rfkill_task.lock, flags);
-}
-
-static void rfkill_schedule_toggle(enum rfkill_type type)
-{
-	unsigned long flags;
-
-	if (rfkill_is_epo_lock_active())
-		return;
-
-	spin_lock_irqsave(&rfkill_task.lock, flags);
-	if (!rfkill_task.global_op_pending) {
-		set_bit(type, rfkill_task.sw_pending);
-		change_bit(type, rfkill_task.sw_togglestate);
-		rfkill_schedule_ratelimited();
-	}
-	spin_unlock_irqrestore(&rfkill_task.lock, flags);
-}
-
-static void rfkill_schedule_evsw_rfkillall(int state)
-{
-	if (state) {
-		switch (rfkill_master_switch_mode) {
-		case RFKILL_INPUT_MASTER_UNBLOCKALL:
-			rfkill_schedule_global_op(RFKILL_GLOBAL_OP_UNBLOCK);
-			break;
-		case RFKILL_INPUT_MASTER_RESTORE:
-			rfkill_schedule_global_op(RFKILL_GLOBAL_OP_RESTORE);
-			break;
-		case RFKILL_INPUT_MASTER_DONOTHING:
-			rfkill_schedule_global_op(RFKILL_GLOBAL_OP_UNLOCK);
-			break;
-		default:
-			/* memory corruption or driver bug! fail safely */
-			rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
-			WARN(1, "Unknown rfkill_master_switch_mode (%d), "
-				"driver bug or memory corruption detected!\n",
-				rfkill_master_switch_mode);
-			break;
-		}
-	} else
-		rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
-}
-
-static void rfkill_event(struct input_handle *handle, unsigned int type,
-			unsigned int code, int data)
-{
-	if (type == EV_KEY && data == 1) {
-		enum rfkill_type t;
-
-		switch (code) {
-		case KEY_WLAN:
-			t = RFKILL_TYPE_WLAN;
-			break;
-		case KEY_BLUETOOTH:
-			t = RFKILL_TYPE_BLUETOOTH;
-			break;
-		case KEY_UWB:
-			t = RFKILL_TYPE_UWB;
-			break;
-		case KEY_WIMAX:
-			t = RFKILL_TYPE_WIMAX;
-			break;
-		default:
-			return;
-		}
-		rfkill_schedule_toggle(t);
-		return;
-	} else if (type == EV_SW) {
-		switch (code) {
-		case SW_RFKILL_ALL:
-			rfkill_schedule_evsw_rfkillall(data);
-			return;
-		default:
-			return;
-		}
-	}
-}
-
-static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
-			  const struct input_device_id *id)
-{
-	struct input_handle *handle;
-	int error;
-
-	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
-	if (!handle)
-		return -ENOMEM;
-
-	handle->dev = dev;
-	handle->handler = handler;
-	handle->name = "rfkill";
-
-	/* causes rfkill_start() to be called */
-	error = input_register_handle(handle);
-	if (error)
-		goto err_free_handle;
-
-	error = input_open_device(handle);
-	if (error)
-		goto err_unregister_handle;
-
-	return 0;
-
- err_unregister_handle:
-	input_unregister_handle(handle);
- err_free_handle:
-	kfree(handle);
-	return error;
-}
-
-static void rfkill_start(struct input_handle *handle)
-{
-	/* Take event_lock to guard against configuration changes, we
-	 * should be able to deal with concurrency with rfkill_event()
-	 * just fine (which event_lock will also avoid). */
-	spin_lock_irq(&handle->dev->event_lock);
-
-	if (test_bit(EV_SW, handle->dev->evbit)) {
-		if (test_bit(SW_RFKILL_ALL, handle->dev->swbit))
-			rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
-							handle->dev->sw));
-		/* add resync for further EV_SW events here */
-	}
-
-	spin_unlock_irq(&handle->dev->event_lock);
-}
-
-static void rfkill_disconnect(struct input_handle *handle)
-{
-	input_close_device(handle);
-	input_unregister_handle(handle);
-	kfree(handle);
-}
-
-static const struct input_device_id rfkill_ids[] = {
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
-	},
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
-	},
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
-	},
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
-	},
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
-		.evbit = { BIT(EV_SW) },
-		.swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
-	},
-	{ }
-};
-
-static struct input_handler rfkill_handler = {
-	.event =	rfkill_event,
-	.connect =	rfkill_connect,
-	.disconnect =	rfkill_disconnect,
-	.start =	rfkill_start,
-	.name =		"rfkill",
-	.id_table =	rfkill_ids,
-};
-
-static int __init rfkill_handler_init(void)
-{
-	if (rfkill_master_switch_mode >= RFKILL_INPUT_MASTER_MAX)
-		return -EINVAL;
-
-	/*
-	 * The penalty to not doing this is a possible RFKILL_OPS_DELAY delay
-	 * at the first use.  Acceptable, but if we can avoid it, why not?
-	 */
-	rfkill_task.last_scheduled =
-			jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
-	return input_register_handler(&rfkill_handler);
-}
-
-static void __exit rfkill_handler_exit(void)
-{
-	input_unregister_handler(&rfkill_handler);
-	cancel_delayed_work_sync(&rfkill_task.dwork);
-	rfkill_remove_epo_lock();
-}
-
-module_init(rfkill_handler_init);
-module_exit(rfkill_handler_exit);