kernel_optimize_test/net/rfkill/input.c
Johannes Berg 19d337dff9 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>
2009-06-03 14:06:13 -04:00

343 lines
8.6 KiB
C

/*
* Input layer to RF Kill interface connector
*
* Copyright (c) 2007 Dmitry Torokhov
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
*
* 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.
*
* If you ever run into a situation in which you have a SW_ type rfkill
* input device, then you can revive code that was removed in the patch
* "rfkill-input: remove unused code".
*/
#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.h"
enum rfkill_input_master_mode {
RFKILL_INPUT_MASTER_UNLOCK = 0,
RFKILL_INPUT_MASTER_RESTORE = 1,
RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
NUM_RFKILL_INPUT_MASTER_MODES
};
/* 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 (only unlock); 1=restore; 2=unblock all");
static spinlock_t rfkill_op_lock;
static bool rfkill_op_pending;
static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
enum rfkill_sched_op {
RFKILL_GLOBAL_OP_EPO = 0,
RFKILL_GLOBAL_OP_RESTORE,
RFKILL_GLOBAL_OP_UNLOCK,
RFKILL_GLOBAL_OP_UNBLOCK,
};
static enum rfkill_sched_op rfkill_master_switch_op;
static enum rfkill_sched_op rfkill_op;
static void __rfkill_handle_global_op(enum rfkill_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 < NUM_RFKILL_TYPES; i++)
rfkill_switch_all(i, false);
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 complement)
{
bool blocked;
blocked = rfkill_get_global_sw_state(type);
if (complement)
blocked = !blocked;
rfkill_switch_all(type, blocked);
}
static void rfkill_op_handler(struct work_struct *work)
{
unsigned int i;
bool c;
spin_lock_irq(&rfkill_op_lock);
do {
if (rfkill_op_pending) {
enum rfkill_sched_op op = rfkill_op;
rfkill_op_pending = false;
memset(rfkill_sw_pending, 0,
sizeof(rfkill_sw_pending));
spin_unlock_irq(&rfkill_op_lock);
__rfkill_handle_global_op(op);
spin_lock_irq(&rfkill_op_lock);
/*
* handle global ops first -- during unlocked period
* we might have gotten a new global op.
*/
if (rfkill_op_pending)
continue;
}
if (rfkill_is_epo_lock_active())
continue;
for (i = 0; i < NUM_RFKILL_TYPES; i++) {
if (__test_and_clear_bit(i, rfkill_sw_pending)) {
c = __test_and_clear_bit(i, rfkill_sw_state);
spin_unlock_irq(&rfkill_op_lock);
__rfkill_handle_normal_op(i, c);
spin_lock_irq(&rfkill_op_lock);
}
}
} while (rfkill_op_pending);
spin_unlock_irq(&rfkill_op_lock);
}
static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
static unsigned long rfkill_last_scheduled;
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_op_work))
return;
schedule_delayed_work(&rfkill_op_work,
rfkill_ratelimit(rfkill_last_scheduled));
rfkill_last_scheduled = jiffies;
}
static void rfkill_schedule_global_op(enum rfkill_sched_op op)
{
unsigned long flags;
spin_lock_irqsave(&rfkill_op_lock, flags);
rfkill_op = op;
rfkill_op_pending = true;
if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
/* bypass the limiter for EPO */
cancel_delayed_work(&rfkill_op_work);
schedule_delayed_work(&rfkill_op_work, 0);
rfkill_last_scheduled = jiffies;
} else
rfkill_schedule_ratelimited();
spin_unlock_irqrestore(&rfkill_op_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_op_lock, flags);
if (!rfkill_op_pending) {
__set_bit(type, rfkill_sw_pending);
__change_bit(type, rfkill_sw_state);
rfkill_schedule_ratelimited();
}
spin_unlock_irqrestore(&rfkill_op_lock, flags);
}
static void rfkill_schedule_evsw_rfkillall(int state)
{
if (state)
rfkill_schedule_global_op(rfkill_master_switch_op);
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) {
switch (code) {
case KEY_WLAN:
rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
break;
case KEY_BLUETOOTH:
rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
break;
case KEY_UWB:
rfkill_schedule_toggle(RFKILL_TYPE_UWB);
break;
case KEY_WIMAX:
rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
break;
}
} else if (type == EV_SW && code == SW_RFKILL_ALL)
rfkill_schedule_evsw_rfkillall(data);
}
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) &&
test_bit(SW_RFKILL_ALL, handle->dev->swbit))
rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
handle->dev->sw));
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 = {
.name = "rfkill",
.event = rfkill_event,
.connect = rfkill_connect,
.start = rfkill_start,
.disconnect = rfkill_disconnect,
.id_table = rfkill_ids,
};
int __init rfkill_handler_init(void)
{
switch (rfkill_master_switch_mode) {
case RFKILL_INPUT_MASTER_UNBLOCKALL:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
break;
case RFKILL_INPUT_MASTER_RESTORE:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
break;
case RFKILL_INPUT_MASTER_UNLOCK:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
break;
default:
return -EINVAL;
}
spin_lock_init(&rfkill_op_lock);
/* Avoid delay at first schedule */
rfkill_last_scheduled =
jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
return input_register_handler(&rfkill_handler);
}
void __exit rfkill_handler_exit(void)
{
input_unregister_handler(&rfkill_handler);
cancel_delayed_work_sync(&rfkill_op_work);
}