dasd.c

优龙2410linux2.6.8内核源代码

		   struct dasd_device * device)
{
	struct dasd_ccw_req *cqr;

	/* Sanity checks */
	if ( magic == NULL || datasize > PAGE_SIZE ||
	     (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
		BUG();
	debug_text_event ( dasd_debug_area, 1, "ALLC");
	debug_text_event ( dasd_debug_area, 1, magic);
	debug_int_event ( dasd_debug_area, 1, cplength);
	debug_int_event ( dasd_debug_area, 1, datasize);

	cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
	if (cqr == NULL)
		return ERR_PTR(-ENOMEM);
	memset(cqr, 0, sizeof(struct dasd_ccw_req));
	cqr->cpaddr = NULL;
	if (cplength > 0) {
		cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
				      GFP_ATOMIC | GFP_DMA);
		if (cqr->cpaddr == NULL) {
			kfree(cqr);
			return ERR_PTR(-ENOMEM);
		}
		memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
	}
	cqr->data = NULL;
	if (datasize > 0) {
		cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
		if (cqr->data == NULL) {
			if (cqr->cpaddr != NULL)
				kfree(cqr->cpaddr);
			kfree(cqr);
			return ERR_PTR(-ENOMEM);
		}
		memset(cqr->data, 0, datasize);
	}
	strncpy((char *) &cqr->magic, magic, 4);
	ASCEBC((char *) &cqr->magic, 4);
	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	dasd_get_device(device);
	return cqr;
}

struct dasd_ccw_req *
dasd_smalloc_request(char *magic, int cplength, int datasize,
		   struct dasd_device * device)
{
	unsigned long flags;
	struct dasd_ccw_req *cqr;
	char *data;
	int size;

	/* Sanity checks */
	if ( magic == NULL || datasize > PAGE_SIZE ||
	     (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
		BUG();
	debug_text_event ( dasd_debug_area, 1, "ALLC");
	debug_text_event ( dasd_debug_area, 1, magic);
	debug_int_event ( dasd_debug_area, 1, cplength);
	debug_int_event ( dasd_debug_area, 1, datasize);

	size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
	if (cplength > 0)
		size += cplength * sizeof(struct ccw1);
	if (datasize > 0)
		size += datasize;
	spin_lock_irqsave(&device->mem_lock, flags);
	cqr = (struct dasd_ccw_req *)
		dasd_alloc_chunk(&device->ccw_chunks, size);
	spin_unlock_irqrestore(&device->mem_lock, flags);
	if (cqr == NULL)
		return ERR_PTR(-ENOMEM);
	memset(cqr, 0, sizeof(struct dasd_ccw_req));
	data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
	cqr->cpaddr = NULL;
	if (cplength > 0) {
		cqr->cpaddr = (struct ccw1 *) data;
		data += cplength*sizeof(struct ccw1);
		memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
	}
	cqr->data = NULL;
	if (datasize > 0) {
		cqr->data = data;
 		memset(cqr->data, 0, datasize);
	}
	strncpy((char *) &cqr->magic, magic, 4);
	ASCEBC((char *) &cqr->magic, 4);
	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	dasd_get_device(device);
	return cqr;
}

/*
 * Free memory of a channel program. This function needs to free all the
 * idal lists that might have been created by dasd_set_cda and the
 * struct dasd_ccw_req itself.
 */
void
dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
{
#ifdef CONFIG_ARCH_S390X
	struct ccw1 *ccw;

	/* Clear any idals used for the request. */
	ccw = cqr->cpaddr;
	do {
		clear_normalized_cda(ccw);
	} while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
#endif
	debug_text_event ( dasd_debug_area, 1, "FREE");
	debug_int_event ( dasd_debug_area, 1, (long) cqr);
	if (cqr->cpaddr != NULL)
		kfree(cqr->cpaddr);
	if (cqr->data != NULL)
		kfree(cqr->data);
	kfree(cqr);
	dasd_put_device(device);
}

void
dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
{
	unsigned long flags;

	debug_text_event(dasd_debug_area, 1, "FREE");
	debug_int_event(dasd_debug_area, 1, (long) cqr);
	spin_lock_irqsave(&device->mem_lock, flags);
	dasd_free_chunk(&device->ccw_chunks, cqr);
	spin_unlock_irqrestore(&device->mem_lock, flags);
	dasd_put_device(device);
}

/*
 * Check discipline magic in cqr.
 */
static inline int
dasd_check_cqr(struct dasd_ccw_req *cqr)
{
	struct dasd_device *device;

	if (cqr == NULL)
		return -EINVAL;
	device = cqr->device;
	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
		DEV_MESSAGE(KERN_WARNING, device,
			    " dasd_ccw_req 0x%08x magic doesn't match"
			    " discipline 0x%08x",
			    cqr->magic,
			    *(unsigned int *) device->discipline->name);
		return -EINVAL;
	}
	return 0;
}

/*
 * Terminate the current i/o and set the request to clear_pending.
 * Timer keeps device runnig.
 * ccw_device_clear can fail if the i/o subsystem
 * is in a bad mood.
 */
int
dasd_term_IO(struct dasd_ccw_req * cqr)
{
	struct dasd_device *device;
	int retries, rc;

	/* Check the cqr */
	rc = dasd_check_cqr(cqr);
	if (rc)
		return rc;
	retries = 0;
	device = (struct dasd_device *) cqr->device;
	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
		rc = ccw_device_clear(device->cdev, (long) cqr);
		switch (rc) {
		case 0:	/* termination successful */
		        if (cqr->retries > 0) {
				cqr->retries--;
				cqr->status = DASD_CQR_CLEAR;
			} else
				cqr->status = DASD_CQR_FAILED;
			cqr->stopclk = get_clock();
			break;
		case -ENODEV:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "device gone, retry");
			break;
		case -EIO:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "I/O error, retry");
			break;
		case -EINVAL:
		case -EBUSY:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "device busy, retry later");
			break;
		default:
			DEV_MESSAGE(KERN_ERR, device,
				    "line %d unknown RC=%d, please "
				    "report to [e-mail]",
				    __LINE__, rc);
			BUG();
			break;
		}
		retries++;
	}
	dasd_schedule_bh(device);
	return rc;
}

/*
 * Start the i/o. This start_IO can fail if the channel is really busy.
 * In that case set up a timer to start the request later.
 */
int
dasd_start_IO(struct dasd_ccw_req * cqr)
{
	struct dasd_device *device;
	int rc;

	/* Check the cqr */
	rc = dasd_check_cqr(cqr);
	if (rc)
		return rc;
	device = (struct dasd_device *) cqr->device;
	if (cqr->retries < 0) {
		DEV_MESSAGE(KERN_DEBUG, device,
			    "start_IO: request %p (%02x/%i) - no retry left.",
			    cqr, cqr->status, cqr->retries);
		cqr->status = DASD_CQR_FAILED;
		return -EIO;
	}
	cqr->startclk = get_clock();
	cqr->starttime = jiffies;
	cqr->retries--;
	rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
			      cqr->lpm, 0);
	switch (rc) {
	case 0:
		cqr->status = DASD_CQR_IN_IO;
		break;
	case -EBUSY:
		DBF_DEV_EVENT(DBF_ERR, device, "%s",
			      "start_IO: device busy, retry later");
		break;
	case -ETIMEDOUT:
		DBF_DEV_EVENT(DBF_ERR, device, "%s",
			      "start_IO: request timeout, retry later");
		break;
	case -ENODEV:
	case -EIO:
		DBF_DEV_EVENT(DBF_ERR, device, "%s",
			      "start_IO: device gone, retry");
		break;
	default:
		DEV_MESSAGE(KERN_ERR, device,
			    "line %d unknown RC=%d, please report"
			    " to [e-mail]", __LINE__, rc);
		BUG();
		break;
	}
	return rc;
}

/*
 * Timeout function for dasd devices. This is used for different purposes
 *  1) missing interrupt handler for normal operation
 *  2) delayed start of request where start_IO failed with -EBUSY
 *  3) timeout for missing state change interrupts
 * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 * DASD_CQR_QUEUED for 2) and 3).
 */
static void
dasd_timeout_device(unsigned long ptr)
{
	unsigned long flags;
	struct dasd_device *device;

	device = (struct dasd_device *) ptr;
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	/* re-activate request queue */
        device->stopped &= ~DASD_STOPPED_PENDING;
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
	dasd_schedule_bh(device);
}

/*
 * Setup timeout for a device in jiffies.
 */
void
dasd_set_timer(struct dasd_device *device, int expires)
{
	if (expires == 0) {
		if (timer_pending(&device->timer))
			del_timer(&device->timer);
		return;
	}
	if (timer_pending(&device->timer)) {
		if (mod_timer(&device->timer, jiffies + expires))
			return;
	}
	device->timer.function = dasd_timeout_device;
	device->timer.data = (unsigned long) device;
	device->timer.expires = jiffies + expires;
	add_timer(&device->timer);
}

/*
 * Clear timeout for a device.
 */
void
dasd_clear_timer(struct dasd_device *device)
{
	if (timer_pending(&device->timer))
		del_timer(&device->timer);
}

static void
dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
{
	struct dasd_ccw_req *cqr;
	struct dasd_device *device;

	cqr = (struct dasd_ccw_req *) intparm;
	if (cqr->status != DASD_CQR_IN_IO) {
		MESSAGE(KERN_DEBUG,
			"invalid status in handle_killed_request: "
			"bus_id %s, status %02x",
			cdev->dev.bus_id, cqr->status);
		return;
	}

	device = (struct dasd_device *) cqr->device;
	if (device == NULL ||
	    device != dasd_device_from_cdev(cdev) ||
	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
		MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
			cdev->dev.bus_id);
		return;
	}

	/* Schedule request to be retried. */
	cqr->status = DASD_CQR_QUEUED;

	dasd_clear_timer(device);
	dasd_schedule_bh(device);
	dasd_put_device(device);
}

static void
dasd_handle_state_change_pending(struct dasd_device *device)
{
	struct dasd_ccw_req *cqr;
	struct list_head *l, *n;

	device->stopped &= ~DASD_STOPPED_PENDING;

        /* restart all 'running' IO on queue */
	list_for_each_safe(l, n, &device->ccw_queue) {
		cqr = list_entry(l, struct dasd_ccw_req, list);
                if (cqr->status == DASD_CQR_IN_IO) {
                        cqr->status = DASD_CQR_QUEUED;
		}
        }
	dasd_clear_timer(device);
	dasd_schedule_bh(device);
}

/*
 * Interrupt handler for "normal" ssch-io based dasd devices.
 */
void
dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
		 struct irb *irb)
{
	struct dasd_ccw_req *cqr, *next;
	struct dasd_device *device;
	unsigned long long now;
	int expires;
	dasd_era_t era;
	char mask;

	if (IS_ERR(irb)) {
		switch (PTR_ERR(irb)) {
		case -EIO:
			dasd_handle_killed_request(cdev, intparm);
			break;
		case -ETIMEDOUT:
			printk(KERN_WARNING"%s(%s): request timed out\n",
			       __FUNCTION__, cdev->dev.bus_id);
			//FIXME - dasd uses own timeout interface...
			break;
		default:
			printk(KERN_WARNING"%s(%s): unknown error %ld\n",
			       __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
		}
		return;
	}

	now = get_clock();

	DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
		  cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
		  (unsigned int) intparm);

	/* first of all check for state change pending interrupt */
	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
	if ((irb->scsw.dstat & mask) == mask) {
		device = dasd_device_from_cdev(cdev);
		if (!IS_ERR(device)) {
			dasd_handle_state_change_pending(device);
			dasd_put_device(device);
		}
		return;
	}

	cqr = (struct dasd_ccw_req *) intparm;

	/* check for unsolicited interrupts */
	if (cqr == NULL) {
		MESSAGE(KERN_DEBUG,
			"unsolicited interrupt received: bus_id %s",
			cdev->dev.bus_id);
		return;
	}

	device = (struct dasd_device *) cqr->device;
	if (device == NULL ||
	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
		MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
			cdev->dev.bus_id);
		return;
	}

	/* Check for clear pending */
	if (cqr->status == DASD_CQR_CLEAR &&
	    irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
		cqr->status = DASD_CQR_QUEUED;
		dasd_clear_timer(device);
		dasd_schedule_bh(device);
		return;
	}

 	/* check status - the request might have been killed by dyn detach */
	if (cqr->status != DASD_CQR_IN_IO) {
		MESSAGE(KERN_DEBUG,
			"invalid status: bus_id %s, status %02x",
			cdev->dev.bus_id, cqr->status);
		return;
	}
	DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x",
		      ((irb->scsw.cstat << 8) | irb->scsw.dstat));

 	/* Find out the appropriate era_action. */
	if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) 
		era = dasd_era_fatal;
	else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
		 irb->scsw.cstat == 0 &&
		 !irb->esw.esw0.erw.cons)
		era = dasd_era_none;
	else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
 	        era = dasd_era_fatal; /* don't recover this request */
	else if (irb->esw.esw0.erw.cons)
		era = device->discipline->examine_error(cqr, irb);
	else 
		era = dasd_era_recover;

	DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
	expires = 0;
	if (era == dasd_era_none) {
		cqr->status = DASD_CQR_DONE;
		cqr->stopclk = now;
		/* Start first request on queue if possible -> fast_io. */
		if (cqr->list.next != &device->ccw_queue) {
			next = list_entry(cqr->list.next,
					  struct dasd_ccw_req, list);
			if ((next->status == DASD_CQR_QUEUED) &&
			    (!device->stopped)) {
				if (device->discipline->start_IO(next) == 0)
					expires = next->expires;
				else
					DEV_MESSAGE(KERN_DEBUG, device, "%s",
						    "Interrupt fastpath "
						    "failed!");
			}
		}
	} else {		/* error */
		memcpy(&cqr->irb, irb, sizeof (struct irb));
#ifdef ERP_DEBUG
		/* dump sense data */
		dasd_log_sense(cqr, irb);
#endif
		switch (era) {
		case dasd_era_fatal:
			cqr->status = DASD_CQR_FAILED;
			cqr->stopclk = now;
			break;
		case dasd_era_recover:
			cqr->status = DASD_CQR_ERROR;
			break;
		default:
			BUG();
		}
	}
	if (expires != 0)
		dasd_set_timer(device, expires);
	else
		dasd_clear_timer(device);
	dasd_schedule_bh(device);
}

/*