From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/net/irda/sir_kthread.c | 502 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 502 insertions(+) create mode 100644 drivers/net/irda/sir_kthread.c (limited to 'drivers/net/irda/sir_kthread.c') diff --git a/drivers/net/irda/sir_kthread.c b/drivers/net/irda/sir_kthread.c new file mode 100644 index 00000000000..18cea109953 --- /dev/null +++ b/drivers/net/irda/sir_kthread.c @@ -0,0 +1,502 @@ +/********************************************************************* + * + * sir_kthread.c: dedicated thread to process scheduled + * sir device setup requests + * + * Copyright (c) 2002 Martin Diehl + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + ********************************************************************/ + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "sir-dev.h" + +/************************************************************************** + * + * kIrDAd kernel thread and config state machine + * + */ + +struct irda_request_queue { + struct list_head request_list; + spinlock_t lock; + task_t *thread; + struct completion exit; + wait_queue_head_t kick, done; + atomic_t num_pending; +}; + +static struct irda_request_queue irda_rq_queue; + +static int irda_queue_request(struct irda_request *rq) +{ + int ret = 0; + unsigned long flags; + + if (!test_and_set_bit(0, &rq->pending)) { + spin_lock_irqsave(&irda_rq_queue.lock, flags); + list_add_tail(&rq->lh_request, &irda_rq_queue.request_list); + wake_up(&irda_rq_queue.kick); + atomic_inc(&irda_rq_queue.num_pending); + spin_unlock_irqrestore(&irda_rq_queue.lock, flags); + ret = 1; + } + return ret; +} + +static void irda_request_timer(unsigned long data) +{ + struct irda_request *rq = (struct irda_request *)data; + unsigned long flags; + + spin_lock_irqsave(&irda_rq_queue.lock, flags); + list_add_tail(&rq->lh_request, &irda_rq_queue.request_list); + wake_up(&irda_rq_queue.kick); + spin_unlock_irqrestore(&irda_rq_queue.lock, flags); +} + +static int irda_queue_delayed_request(struct irda_request *rq, unsigned long delay) +{ + int ret = 0; + struct timer_list *timer = &rq->timer; + + if (!test_and_set_bit(0, &rq->pending)) { + timer->expires = jiffies + delay; + timer->function = irda_request_timer; + timer->data = (unsigned long)rq; + atomic_inc(&irda_rq_queue.num_pending); + add_timer(timer); + ret = 1; + } + return ret; +} + +static void run_irda_queue(void) +{ + unsigned long flags; + struct list_head *entry, *tmp; + struct irda_request *rq; + + spin_lock_irqsave(&irda_rq_queue.lock, flags); + list_for_each_safe(entry, tmp, &irda_rq_queue.request_list) { + rq = list_entry(entry, struct irda_request, lh_request); + list_del_init(entry); + spin_unlock_irqrestore(&irda_rq_queue.lock, flags); + + clear_bit(0, &rq->pending); + rq->func(rq->data); + + if (atomic_dec_and_test(&irda_rq_queue.num_pending)) + wake_up(&irda_rq_queue.done); + + spin_lock_irqsave(&irda_rq_queue.lock, flags); + } + spin_unlock_irqrestore(&irda_rq_queue.lock, flags); +} + +static int irda_thread(void *startup) +{ + DECLARE_WAITQUEUE(wait, current); + + daemonize("kIrDAd"); + + irda_rq_queue.thread = current; + + complete((struct completion *)startup); + + while (irda_rq_queue.thread != NULL) { + + /* We use TASK_INTERRUPTIBLE, rather than + * TASK_UNINTERRUPTIBLE. Andrew Morton made this + * change ; he told me that it is safe, because "signal + * blocking is now handled in daemonize()", he added + * that the problem is that "uninterruptible sleep + * contributes to load average", making user worry. + * Jean II */ + set_task_state(current, TASK_INTERRUPTIBLE); + add_wait_queue(&irda_rq_queue.kick, &wait); + if (list_empty(&irda_rq_queue.request_list)) + schedule(); + else + __set_task_state(current, TASK_RUNNING); + remove_wait_queue(&irda_rq_queue.kick, &wait); + + /* make swsusp happy with our thread */ + if (current->flags & PF_FREEZE) + refrigerator(PF_FREEZE); + + run_irda_queue(); + } + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,35) + reparent_to_init(); +#endif + complete_and_exit(&irda_rq_queue.exit, 0); + /* never reached */ + return 0; +} + + +static void flush_irda_queue(void) +{ + if (atomic_read(&irda_rq_queue.num_pending)) { + + DECLARE_WAITQUEUE(wait, current); + + if (!list_empty(&irda_rq_queue.request_list)) + run_irda_queue(); + + set_task_state(current, TASK_UNINTERRUPTIBLE); + add_wait_queue(&irda_rq_queue.done, &wait); + if (atomic_read(&irda_rq_queue.num_pending)) + schedule(); + else + __set_task_state(current, TASK_RUNNING); + remove_wait_queue(&irda_rq_queue.done, &wait); + } +} + +/* substate handler of the config-fsm to handle the cases where we want + * to wait for transmit completion before changing the port configuration + */ + +static int irda_tx_complete_fsm(struct sir_dev *dev) +{ + struct sir_fsm *fsm = &dev->fsm; + unsigned next_state, delay; + unsigned bytes_left; + + do { + next_state = fsm->substate; /* default: stay in current substate */ + delay = 0; + + switch(fsm->substate) { + + case SIRDEV_STATE_WAIT_XMIT: + if (dev->drv->chars_in_buffer) + bytes_left = dev->drv->chars_in_buffer(dev); + else + bytes_left = 0; + if (!bytes_left) { + next_state = SIRDEV_STATE_WAIT_UNTIL_SENT; + break; + } + + if (dev->speed > 115200) + delay = (bytes_left*8*10000) / (dev->speed/100); + else if (dev->speed > 0) + delay = (bytes_left*10*10000) / (dev->speed/100); + else + delay = 0; + /* expected delay (usec) until remaining bytes are sent */ + if (delay < 100) { + udelay(delay); + delay = 0; + break; + } + /* sleep some longer delay (msec) */ + delay = (delay+999) / 1000; + break; + + case SIRDEV_STATE_WAIT_UNTIL_SENT: + /* block until underlaying hardware buffer are empty */ + if (dev->drv->wait_until_sent) + dev->drv->wait_until_sent(dev); + next_state = SIRDEV_STATE_TX_DONE; + break; + + case SIRDEV_STATE_TX_DONE: + return 0; + + default: + IRDA_ERROR("%s - undefined state\n", __FUNCTION__); + return -EINVAL; + } + fsm->substate = next_state; + } while (delay == 0); + return delay; +} + +/* + * Function irda_config_fsm + * + * State machine to handle the configuration of the device (and attached dongle, if any). + * This handler is scheduled for execution in kIrDAd context, so we can sleep. + * however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too + * long. Instead, for longer delays we start a timer to reschedule us later. + * On entry, fsm->sem is always locked and the netdev xmit queue stopped. + * Both must be unlocked/restarted on completion - but only on final exit. + */ + +static void irda_config_fsm(void *data) +{ + struct sir_dev *dev = data; + struct sir_fsm *fsm = &dev->fsm; + int next_state; + int ret = -1; + unsigned delay; + + IRDA_DEBUG(2, "%s(), <%ld>\n", __FUNCTION__, jiffies); + + do { + IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n", + __FUNCTION__, fsm->state, fsm->substate); + + next_state = fsm->state; + delay = 0; + + switch(fsm->state) { + + case SIRDEV_STATE_DONGLE_OPEN: + if (dev->dongle_drv != NULL) { + ret = sirdev_put_dongle(dev); + if (ret) { + fsm->result = -EINVAL; + next_state = SIRDEV_STATE_ERROR; + break; + } + } + + /* Initialize dongle */ + ret = sirdev_get_dongle(dev, fsm->param); + if (ret) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + + /* Dongles are powered through the modem control lines which + * were just set during open. Before resetting, let's wait for + * the power to stabilize. This is what some dongle drivers did + * in open before, while others didn't - should be safe anyway. + */ + + delay = 50; + fsm->substate = SIRDEV_STATE_DONGLE_RESET; + next_state = SIRDEV_STATE_DONGLE_RESET; + + fsm->param = 9600; + + break; + + case SIRDEV_STATE_DONGLE_CLOSE: + /* shouldn't we just treat this as success=? */ + if (dev->dongle_drv == NULL) { + fsm->result = -EINVAL; + next_state = SIRDEV_STATE_ERROR; + break; + } + + ret = sirdev_put_dongle(dev); + if (ret) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + next_state = SIRDEV_STATE_DONE; + break; + + case SIRDEV_STATE_SET_DTR_RTS: + ret = sirdev_set_dtr_rts(dev, + (fsm->param&0x02) ? TRUE : FALSE, + (fsm->param&0x01) ? TRUE : FALSE); + next_state = SIRDEV_STATE_DONE; + break; + + case SIRDEV_STATE_SET_SPEED: + fsm->substate = SIRDEV_STATE_WAIT_XMIT; + next_state = SIRDEV_STATE_DONGLE_CHECK; + break; + + case SIRDEV_STATE_DONGLE_CHECK: + ret = irda_tx_complete_fsm(dev); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + if ((delay=ret) != 0) + break; + + if (dev->dongle_drv) { + fsm->substate = SIRDEV_STATE_DONGLE_RESET; + next_state = SIRDEV_STATE_DONGLE_RESET; + } + else { + dev->speed = fsm->param; + next_state = SIRDEV_STATE_PORT_SPEED; + } + break; + + case SIRDEV_STATE_DONGLE_RESET: + if (dev->dongle_drv->reset) { + ret = dev->dongle_drv->reset(dev); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + } + else + ret = 0; + if ((delay=ret) == 0) { + /* set serial port according to dongle default speed */ + if (dev->drv->set_speed) + dev->drv->set_speed(dev, dev->speed); + fsm->substate = SIRDEV_STATE_DONGLE_SPEED; + next_state = SIRDEV_STATE_DONGLE_SPEED; + } + break; + + case SIRDEV_STATE_DONGLE_SPEED: + if (dev->dongle_drv->reset) { + ret = dev->dongle_drv->set_speed(dev, fsm->param); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + } + else + ret = 0; + if ((delay=ret) == 0) + next_state = SIRDEV_STATE_PORT_SPEED; + break; + + case SIRDEV_STATE_PORT_SPEED: + /* Finally we are ready to change the serial port speed */ + if (dev->drv->set_speed) + dev->drv->set_speed(dev, dev->speed); + dev->new_speed = 0; + next_state = SIRDEV_STATE_DONE; + break; + + case SIRDEV_STATE_DONE: + /* Signal network layer so it can send more frames */ + netif_wake_queue(dev->netdev); + next_state = SIRDEV_STATE_COMPLETE; + break; + + default: + IRDA_ERROR("%s - undefined state\n", __FUNCTION__); + fsm->result = -EINVAL; + /* fall thru */ + + case SIRDEV_STATE_ERROR: + IRDA_ERROR("%s - error: %d\n", __FUNCTION__, fsm->result); + +#if 0 /* don't enable this before we have netdev->tx_timeout to recover */ + netif_stop_queue(dev->netdev); +#else + netif_wake_queue(dev->netdev); +#endif + /* fall thru */ + + case SIRDEV_STATE_COMPLETE: + /* config change finished, so we are not busy any longer */ + sirdev_enable_rx(dev); + up(&fsm->sem); + return; + } + fsm->state = next_state; + } while(!delay); + + irda_queue_delayed_request(&fsm->rq, msecs_to_jiffies(delay)); +} + +/* schedule some device configuration task for execution by kIrDAd + * on behalf of the above state machine. + * can be called from process or interrupt/tasklet context. + */ + +int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param) +{ + struct sir_fsm *fsm = &dev->fsm; + int xmit_was_down; + + IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __FUNCTION__, initial_state, param); + + if (down_trylock(&fsm->sem)) { + if (in_interrupt() || in_atomic() || irqs_disabled()) { + IRDA_DEBUG(1, "%s(), state machine busy!\n", __FUNCTION__); + return -EWOULDBLOCK; + } else + down(&fsm->sem); + } + + if (fsm->state == SIRDEV_STATE_DEAD) { + /* race with sirdev_close should never happen */ + IRDA_ERROR("%s(), instance staled!\n", __FUNCTION__); + up(&fsm->sem); + return -ESTALE; /* or better EPIPE? */ + } + + xmit_was_down = netif_queue_stopped(dev->netdev); + netif_stop_queue(dev->netdev); + atomic_set(&dev->enable_rx, 0); + + fsm->state = initial_state; + fsm->param = param; + fsm->result = 0; + + INIT_LIST_HEAD(&fsm->rq.lh_request); + fsm->rq.pending = 0; + fsm->rq.func = irda_config_fsm; + fsm->rq.data = dev; + + if (!irda_queue_request(&fsm->rq)) { /* returns 0 on error! */ + atomic_set(&dev->enable_rx, 1); + if (!xmit_was_down) + netif_wake_queue(dev->netdev); + up(&fsm->sem); + return -EAGAIN; + } + return 0; +} + +int __init irda_thread_create(void) +{ + struct completion startup; + int pid; + + spin_lock_init(&irda_rq_queue.lock); + irda_rq_queue.thread = NULL; + INIT_LIST_HEAD(&irda_rq_queue.request_list); + init_waitqueue_head(&irda_rq_queue.kick); + init_waitqueue_head(&irda_rq_queue.done); + atomic_set(&irda_rq_queue.num_pending, 0); + + init_completion(&startup); + pid = kernel_thread(irda_thread, &startup, CLONE_FS|CLONE_FILES); + if (pid <= 0) + return -EAGAIN; + else + wait_for_completion(&startup); + + return 0; +} + +void __exit irda_thread_join(void) +{ + if (irda_rq_queue.thread) { + flush_irda_queue(); + init_completion(&irda_rq_queue.exit); + irda_rq_queue.thread = NULL; + wake_up(&irda_rq_queue.kick); + wait_for_completion(&irda_rq_queue.exit); + } +} + -- cgit v1.2.3