ctcmain.c

linux-2.6.15.6

{
	struct channel *ch = (struct channel *) arg;
	struct channel *ch2;
	struct net_device *dev = ch->netdev;

	DBF_TEXT(trace, 3, __FUNCTION__);
	fsm_deltimer(&ch->timer);
	ctc_pr_debug("%s: Got remote disconnect, re-initializing ...\n",
		     dev->name);

	/**
	 * Notify device statemachine
	 */
	fsm_event(((struct ctc_priv *) dev->priv)->fsm, DEV_EVENT_RXDOWN, dev);
	fsm_event(((struct ctc_priv *) dev->priv)->fsm, DEV_EVENT_TXDOWN, dev);

	fsm_newstate(fi, CH_STATE_DTERM);
	ch2 = ((struct ctc_priv *) dev->priv)->channel[WRITE];
	fsm_newstate(ch2->fsm, CH_STATE_DTERM);

	ccw_device_halt(ch->cdev, (unsigned long) ch);
	ccw_device_halt(ch2->cdev, (unsigned long) ch2);
}

/**
 * Handle error during TX channel initialization.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_txiniterr(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	struct net_device *dev = ch->netdev;

	DBF_TEXT(setup, 2, __FUNCTION__);
	if (event == CH_EVENT_TIMER) {
		fsm_deltimer(&ch->timer);
		ctc_pr_debug("%s: Timeout during TX init handshake\n", dev->name);
		if (ch->retry++ < 3)
			ch_action_restart(fi, event, arg);
		else {
			fsm_newstate(fi, CH_STATE_TXERR);
			fsm_event(((struct ctc_priv *) dev->priv)->fsm,
				  DEV_EVENT_TXDOWN, dev);
		}
	} else
		ctc_pr_warn("%s: Error during TX init handshake\n", dev->name);
}

/**
 * Handle TX timeout by retrying operation.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_txretry(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	struct net_device *dev = ch->netdev;
	unsigned long saveflags;

	DBF_TEXT(trace, 4, __FUNCTION__);
	fsm_deltimer(&ch->timer);
	if (ch->retry++ > 3) {
		ctc_pr_debug("%s: TX retry failed, restarting channel\n",
			     dev->name);
		fsm_event(((struct ctc_priv *) dev->priv)->fsm,
			  DEV_EVENT_TXDOWN, dev);
		ch_action_restart(fi, event, arg);
	} else {
		struct sk_buff *skb;

		ctc_pr_debug("%s: TX retry %d\n", dev->name, ch->retry);
		if ((skb = skb_peek(&ch->io_queue))) {
			int rc = 0;

			clear_normalized_cda(&ch->ccw[4]);
			ch->ccw[4].count = skb->len;
			if (set_normalized_cda(&ch->ccw[4], skb->data)) {
				ctc_pr_debug(
					"%s: IDAL alloc failed, chan restart\n",
					dev->name);
				fsm_event(((struct ctc_priv *) dev->priv)->fsm,
					  DEV_EVENT_TXDOWN, dev);
				ch_action_restart(fi, event, arg);
				return;
			}
			fsm_addtimer(&ch->timer, 1000, CH_EVENT_TIMER, ch);
			saveflags = 0;	/* avoids compiler warning with
					   spin_unlock_irqrestore */
			if (event == CH_EVENT_TIMER) // only for TIMER not yet locked
				spin_lock_irqsave(get_ccwdev_lock(ch->cdev),
						  saveflags);
			rc = ccw_device_start(ch->cdev, &ch->ccw[3],
					      (unsigned long) ch, 0xff, 0);
			if (event == CH_EVENT_TIMER)
				spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev),
						       saveflags);
			if (rc != 0) {
				fsm_deltimer(&ch->timer);
				ccw_check_return_code(ch, rc, "TX in ch_action_txretry");
				ctc_purge_skb_queue(&ch->io_queue);
			}
		}
	}

}

/**
 * Handle fatal errors during an I/O command.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_iofatal(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	struct net_device *dev = ch->netdev;

	DBF_TEXT(trace, 3, __FUNCTION__);
	fsm_deltimer(&ch->timer);
	if (CHANNEL_DIRECTION(ch->flags) == READ) {
		ctc_pr_debug("%s: RX I/O error\n", dev->name);
		fsm_newstate(fi, CH_STATE_RXERR);
		fsm_event(((struct ctc_priv *) dev->priv)->fsm,
			  DEV_EVENT_RXDOWN, dev);
	} else {
		ctc_pr_debug("%s: TX I/O error\n", dev->name);
		fsm_newstate(fi, CH_STATE_TXERR);
		fsm_event(((struct ctc_priv *) dev->priv)->fsm,
			  DEV_EVENT_TXDOWN, dev);
	}
}

static void 
ch_action_reinit(fsm_instance *fi, int event, void *arg)
{
 	struct channel *ch = (struct channel *)arg;
 	struct net_device *dev = ch->netdev;
 	struct ctc_priv *privptr = dev->priv;
 
	DBF_TEXT(trace, 4, __FUNCTION__);
 	ch_action_iofatal(fi, event, arg);
 	fsm_addtimer(&privptr->restart_timer, 1000, DEV_EVENT_RESTART, dev);
}

/**
 * The statemachine for a channel.
 */
static const fsm_node ch_fsm[] = {
	{CH_STATE_STOPPED,    CH_EVENT_STOP,       fsm_action_nop       },
	{CH_STATE_STOPPED,    CH_EVENT_START,      ch_action_start      },
	{CH_STATE_STOPPED,    CH_EVENT_FINSTAT,    fsm_action_nop       },
	{CH_STATE_STOPPED,    CH_EVENT_MC_FAIL,    fsm_action_nop       },

	{CH_STATE_NOTOP,      CH_EVENT_STOP,       ch_action_stop       },
	{CH_STATE_NOTOP,      CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_NOTOP,      CH_EVENT_FINSTAT,    fsm_action_nop       },
	{CH_STATE_NOTOP,      CH_EVENT_MC_FAIL,    fsm_action_nop       },
	{CH_STATE_NOTOP,      CH_EVENT_MC_GOOD,    ch_action_start      },

	{CH_STATE_STARTWAIT,  CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_STARTWAIT,  CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_STARTWAIT,  CH_EVENT_FINSTAT,    ch_action_setmode    },
	{CH_STATE_STARTWAIT,  CH_EVENT_TIMER,      ch_action_setuperr   },
	{CH_STATE_STARTWAIT,  CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_STARTWAIT,  CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_STARTWAIT,  CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_STARTRETRY, CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_STARTRETRY, CH_EVENT_TIMER,      ch_action_setmode    },
	{CH_STATE_STARTRETRY, CH_EVENT_FINSTAT,    fsm_action_nop       },
	{CH_STATE_STARTRETRY, CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_SETUPWAIT,  CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_SETUPWAIT,  CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_SETUPWAIT,  CH_EVENT_FINSTAT,    ch_action_firstio    },
	{CH_STATE_SETUPWAIT,  CH_EVENT_UC_RCRESET, ch_action_setuperr   },
	{CH_STATE_SETUPWAIT,  CH_EVENT_UC_RSRESET, ch_action_setuperr   },
	{CH_STATE_SETUPWAIT,  CH_EVENT_TIMER,      ch_action_setmode    },
	{CH_STATE_SETUPWAIT,  CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_SETUPWAIT,  CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_SETUPWAIT,  CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_RXINIT,     CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_RXINIT,     CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_RXINIT,     CH_EVENT_FINSTAT,    ch_action_rxidle     },
	{CH_STATE_RXINIT,     CH_EVENT_UC_RCRESET, ch_action_rxiniterr  },
	{CH_STATE_RXINIT,     CH_EVENT_UC_RSRESET, ch_action_rxiniterr  },
	{CH_STATE_RXINIT,     CH_EVENT_TIMER,      ch_action_rxiniterr  },
	{CH_STATE_RXINIT,     CH_EVENT_ATTNBUSY,   ch_action_rxinitfail },
	{CH_STATE_RXINIT,     CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_RXINIT,     CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_RXINIT,     CH_EVENT_UC_ZERO,    ch_action_firstio    },
	{CH_STATE_RXINIT,     CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_RXIDLE,     CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_RXIDLE,     CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_RXIDLE,     CH_EVENT_FINSTAT,    ch_action_rx         },
	{CH_STATE_RXIDLE,     CH_EVENT_UC_RCRESET, ch_action_rxdisc     },
//      {CH_STATE_RXIDLE,     CH_EVENT_UC_RSRESET, ch_action_rxretry    },
	{CH_STATE_RXIDLE,     CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_RXIDLE,     CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_RXIDLE,     CH_EVENT_MC_FAIL,    ch_action_fail       },
	{CH_STATE_RXIDLE,     CH_EVENT_UC_ZERO,    ch_action_rx         },

	{CH_STATE_TXINIT,     CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_TXINIT,     CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_TXINIT,     CH_EVENT_FINSTAT,    ch_action_txidle     },
	{CH_STATE_TXINIT,     CH_EVENT_UC_RCRESET, ch_action_txiniterr  },
	{CH_STATE_TXINIT,     CH_EVENT_UC_RSRESET, ch_action_txiniterr  },
	{CH_STATE_TXINIT,     CH_EVENT_TIMER,      ch_action_txiniterr  },
	{CH_STATE_TXINIT,     CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_TXINIT,     CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_TXINIT,     CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_TXIDLE,     CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_TXIDLE,     CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_TXIDLE,     CH_EVENT_FINSTAT,    ch_action_firstio    },
	{CH_STATE_TXIDLE,     CH_EVENT_UC_RCRESET, fsm_action_nop       },
	{CH_STATE_TXIDLE,     CH_EVENT_UC_RSRESET, fsm_action_nop       },
	{CH_STATE_TXIDLE,     CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_TXIDLE,     CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_TXIDLE,     CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_TERM,       CH_EVENT_STOP,       fsm_action_nop       },
	{CH_STATE_TERM,       CH_EVENT_START,      ch_action_restart    },
	{CH_STATE_TERM,       CH_EVENT_FINSTAT,    ch_action_stopped    },
	{CH_STATE_TERM,       CH_EVENT_UC_RCRESET, fsm_action_nop       },
	{CH_STATE_TERM,       CH_EVENT_UC_RSRESET, fsm_action_nop       },
	{CH_STATE_TERM,       CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_DTERM,      CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_DTERM,      CH_EVENT_START,      ch_action_restart    },
	{CH_STATE_DTERM,      CH_EVENT_FINSTAT,    ch_action_setmode    },
	{CH_STATE_DTERM,      CH_EVENT_UC_RCRESET, fsm_action_nop       },
	{CH_STATE_DTERM,      CH_EVENT_UC_RSRESET, fsm_action_nop       },
	{CH_STATE_DTERM,      CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_TX,         CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_TX,         CH_EVENT_START,      fsm_action_nop       },
	{CH_STATE_TX,         CH_EVENT_FINSTAT,    ch_action_txdone     },
	{CH_STATE_TX,         CH_EVENT_UC_RCRESET, ch_action_txretry    },
	{CH_STATE_TX,         CH_EVENT_UC_RSRESET, ch_action_txretry    },
	{CH_STATE_TX,         CH_EVENT_TIMER,      ch_action_txretry    },
	{CH_STATE_TX,         CH_EVENT_IO_ENODEV,  ch_action_iofatal    },
	{CH_STATE_TX,         CH_EVENT_IO_EIO,     ch_action_reinit     },
	{CH_STATE_TX,         CH_EVENT_MC_FAIL,    ch_action_fail       },

	{CH_STATE_RXERR,      CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_TXERR,      CH_EVENT_STOP,       ch_action_haltio     },
	{CH_STATE_TXERR,      CH_EVENT_MC_FAIL,    ch_action_fail       },
	{CH_STATE_RXERR,      CH_EVENT_MC_FAIL,    ch_action_fail       },
};

static const int CH_FSM_LEN = sizeof (ch_fsm) / sizeof (fsm_node);

/**
 * Functions related to setup and device detection.
 *****************************************************************************/

static inline int
less_than(char *id1, char *id2)
{
	int dev1, dev2, i;

	for (i = 0; i < 5; i++) {
		id1++;
		id2++;
	}
	dev1 = simple_strtoul(id1, &id1, 16);
	dev2 = simple_strtoul(id2, &id2, 16);
	
	return (dev1 < dev2);
}

/**
 * Add a new channel to the list of channels.
 * Keeps the channel list sorted.
 *
 * @param cdev  The ccw_device to be added.
 * @param type  The type class of the new channel.
 *
 * @return 0 on success, !0 on error.
 */
static int
add_channel(struct ccw_device *cdev, enum channel_types type)
{
	struct channel **c = &channels;
	struct channel *ch;

	DBF_TEXT(trace, 2, __FUNCTION__);
	if ((ch =
	     (struct channel *) kmalloc(sizeof (struct channel),
					GFP_KERNEL)) == NULL) {
		ctc_pr_warn("ctc: Out of memory in add_channel\n");
		return -1;
	}
	memset(ch, 0, sizeof (struct channel));
	if ((ch->ccw = (struct ccw1 *) kmalloc(8*sizeof(struct ccw1),
					       GFP_KERNEL | GFP_DMA)) == NULL) {
		kfree(ch);
		ctc_pr_warn("ctc: Out of memory in add_channel\n");
		return -1;
	}

	memset(ch->ccw, 0, 8*sizeof(struct ccw1));	// assure all flags and counters are reset

	/**
	 * "static" ccws are used in the following way:
	 *
	 * ccw[0..2] (Channel program for generic I/O):
	 *           0: prepare
	 *           1: read or write (depending on direction) with fixed
	 *              buffer (idal allocated once when buffer is allocated)
	 *           2: nop
	 * ccw[3..5] (Channel program for direct write of packets)
	 *           3: prepare
	 *           4: write (idal allocated on every write).
	 *           5: nop
	 * ccw[6..7] (Channel program for initial channel setup):
	 *           6: set extended mode
	 *           7: nop
	 *
	 * ch->ccw[0..5] are initialized in ch_action_start because
	 * the channel's direction is yet unknown here.
	 */
	ch->ccw[6].cmd_code = CCW_CMD_SET_EXTENDED;
	ch->ccw[6].flags = CCW_FLAG_SLI;

	ch->ccw[7].cmd_code = CCW_CMD_NOOP;
	ch->ccw[7].flags = CCW_FLAG_SLI;

	ch->cdev = cdev;
	snprintf(ch->id, CTC_ID_SIZE, "ch-%s", cdev->dev.bus_id);
	ch->type = type;
	ch->fsm = init_fsm(ch->id, ch_state_names,
			   ch_event_names, NR_CH_STATES, NR_CH_EVENTS,
			   ch_fsm, CH_FSM_LEN, GFP_KERNEL);
	if (ch->fsm == NULL) {
		ctc_pr_warn("ctc: Could not create FSM in add_channel\n");
		kfree(ch->ccw);
		kfree(ch);
		return -1;
	}
	fsm_newstate(ch->fsm, CH_STATE_IDLE);
	if ((ch->irb = (struct irb *) kmalloc(sizeof (struct irb),
					      GFP_KERNEL)) == NULL) {
		ctc_pr_warn("ctc: Out of memory in add_channel\n");
		kfree_fsm(ch->fsm);
		kfree(ch->ccw);
		kfree(ch);
		return -1;
	}
	memset(ch->irb, 0, sizeof (struct irb));
	while (*c && less_than((*c)->id, ch->id))
		c = &(*c)->next;
	if (*c && (!strncmp((*c)->id, ch->id, CTC_ID_SIZE))) {
		ctc_pr_debug(
			"ctc: add_channel: device %s already in list, "
			"using old entry\n", (*c)->id);
		kfree(ch->irb);
		kfree_fsm(ch->fsm);
		kfree(ch->ccw);
		kfree(ch);
		return 0;
	}
	fsm_settimer(ch->fsm, &ch->timer);
	skb_queue_head_init(&ch->io_queue);
	skb_queue_head_init(&ch->collect_queue);
	ch->next = *c;
	*c = ch;
	return 0;
}

/**
 * Release a specific channel in the channel list.
 *
 * @param ch Pointer to channel struct to be released.
 */
static void
channel_free(struct channel *ch)
{
	ch->flags &= ~CHANNEL_FLAGS_INUSE;
	fsm_newstate(ch->fsm, CH_STATE_IDLE);
}

/**
 * Remove a specific channel in the channel list.
 *
 * @param ch Pointer to channel struct to be released.
 */
static void
channel_remove(struct channel *ch)
{
	struct channel **c = &channels;

	DBF_TEXT(trace, 2, __FUNCTION__);
	if (ch == NULL)
		return;

	channel_free(ch);
	while (*c) {
		if (*c == ch) {
			*c = ch->next;
			fsm_deltimer(&ch->timer);
			kfree_fsm(ch->fsm);
			clear_normalized_cda(&ch->ccw[4]);
			if (ch->trans_skb != NULL) {
				clear_normalized_cda(&ch->ccw[1]);
				dev_kfree_skb(ch->trans_skb);
			}
			kfree(ch->ccw);
			kfree(ch->irb);
			kfree(ch);
			return;
		}
		c = &((*c)->next);
	}
}

/**
 * Get a specific channel from the channel list.
 *
 * @param type Type of channel we are interested in.
 * @param id Id of channel we are interested in.
 * @param direction Direction we want to use this channel for.
 *
 * @return Pointer to a channel or NULL if no matching channel available.
 */
static struct channel
*
channel_get(enum channel_types type, char *id, int direction)
{
	struct channel *ch = channels;

	DBF_TEXT(trace, 3, __FUNCTION__);
#ifdef DEBUG
	ctc_pr_debug("ctc: %s(): searching for ch with id %s and type %d\n",
		     __func__, id, type);
#endif

	while (ch && ((strncmp(ch->id, id, CTC_ID_SIZE)) || (ch->type != type))) {
#ifdef DEBUG
		ctc_pr_debug("ctc: %s(): ch=0x%p (id=%s, type=%d\n",
			     __func__, ch, ch->id, ch->type);
#endif