device.c 27.9 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206
/*
 *  drivers/s390/cio/device.c
 *  bus driver for ccw devices
 *   $Revision: 1.131 $
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *			 IBM Corporation
 *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
 *		 Cornelia Huck (cohuck@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/workqueue.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>

#include "cio.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"

/******************* bus type handling ***********************/

/* The Linux driver model distinguishes between a bus type and
 * the bus itself. Of course we only have one channel
 * subsystem driver and one channel system per machine, but
 * we still use the abstraction. T.R. says it's a good idea. */
static int
ccw_bus_match (struct device * dev, struct device_driver * drv)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_driver *cdrv = to_ccwdrv(drv);
	const struct ccw_device_id *ids = cdrv->ids, *found;

	if (!ids)
		return 0;

	found = ccw_device_id_match(ids, &cdev->id);
	if (!found)
		return 0;

	cdev->id.driver_info = found->driver_info;

	return 1;
}

/*
 * Hotplugging interface for ccw devices.
 * Heavily modeled on pci and usb hotplug.
 */
static int
ccw_hotplug (struct device *dev, char **envp, int num_envp,
	     char *buffer, int buffer_size)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	int i = 0;
	int length = 0;

	if (!cdev)
		return -ENODEV;

	/* what we want to pass to /sbin/hotplug */

	envp[i++] = buffer;
	length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
			   cdev->id.cu_type);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	buffer += length;

	envp[i++] = buffer;
	length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
			   cdev->id.cu_model);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	buffer += length;

	/* The next two can be zero, that's ok for us */
	envp[i++] = buffer;
	length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
			   cdev->id.dev_type);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;
	++length;
	buffer += length;

	envp[i++] = buffer;
	length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
			   cdev->id.dev_model);
	if ((buffer_size - length <= 0) || (i >= num_envp))
		return -ENOMEM;

	envp[i] = 0;

	return 0;
}

struct bus_type ccw_bus_type = {
	.name  = "ccw",
	.match = &ccw_bus_match,
	.hotplug = &ccw_hotplug,
};

static int io_subchannel_probe (struct device *);
static int io_subchannel_remove (struct device *);
void io_subchannel_irq (struct device *);
static int io_subchannel_notify(struct device *, int);
static void io_subchannel_verify(struct device *);
static void io_subchannel_ioterm(struct device *);
static void io_subchannel_shutdown(struct device *);

struct css_driver io_subchannel_driver = {
	.subchannel_type = SUBCHANNEL_TYPE_IO,
	.drv = {
		.name = "io_subchannel",
		.bus  = &css_bus_type,
		.probe = &io_subchannel_probe,
		.remove = &io_subchannel_remove,
		.shutdown = &io_subchannel_shutdown,
	},
	.irq = io_subchannel_irq,
	.notify = io_subchannel_notify,
	.verify = io_subchannel_verify,
	.termination = io_subchannel_ioterm,
};

struct workqueue_struct *ccw_device_work;
struct workqueue_struct *ccw_device_notify_work;
static wait_queue_head_t ccw_device_init_wq;
static atomic_t ccw_device_init_count;

static int __init
init_ccw_bus_type (void)
{
	int ret;

	init_waitqueue_head(&ccw_device_init_wq);
	atomic_set(&ccw_device_init_count, 0);

	ccw_device_work = create_singlethread_workqueue("cio");
	if (!ccw_device_work)
		return -ENOMEM; /* FIXME: better errno ? */
	ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
	if (!ccw_device_notify_work) {
		ret = -ENOMEM; /* FIXME: better errno ? */
		goto out_err;
	}
	slow_path_wq = create_singlethread_workqueue("kslowcrw");
	if (!slow_path_wq) {
		ret = -ENOMEM; /* FIXME: better errno ? */
		goto out_err;
	}
	if ((ret = bus_register (&ccw_bus_type)))
		goto out_err;

	if ((ret = driver_register(&io_subchannel_driver.drv)))
		goto out_err;

	wait_event(ccw_device_init_wq,
		   atomic_read(&ccw_device_init_count) == 0);
	flush_workqueue(ccw_device_work);
	return 0;
out_err:
	if (ccw_device_work)
		destroy_workqueue(ccw_device_work);
	if (ccw_device_notify_work)
		destroy_workqueue(ccw_device_notify_work);
	if (slow_path_wq)
		destroy_workqueue(slow_path_wq);
	return ret;
}

static void __exit
cleanup_ccw_bus_type (void)
{
	driver_unregister(&io_subchannel_driver.drv);
	bus_unregister(&ccw_bus_type);
	destroy_workqueue(ccw_device_notify_work);
	destroy_workqueue(ccw_device_work);
}

subsys_initcall(init_ccw_bus_type);
module_exit(cleanup_ccw_bus_type);

/************************ device handling **************************/

/*
 * A ccw_device has some interfaces in sysfs in addition to the
 * standard ones.
 * The following entries are designed to export the information which
 * resided in 2.4 in /proc/subchannels. Subchannel and device number
 * are obvious, so they don't have an entry :)
 * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 */
static ssize_t
207
chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
L
Linus Torvalds 已提交
208 209 210 211 212 213 214 215 216 217 218 219 220 221
{
	struct subchannel *sch = to_subchannel(dev);
	struct ssd_info *ssd = &sch->ssd_info;
	ssize_t ret = 0;
	int chp;

	for (chp = 0; chp < 8; chp++)
		ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);

	ret += sprintf (buf+ret, "\n");
	return min((ssize_t)PAGE_SIZE, ret);
}

static ssize_t
222
pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
L
Linus Torvalds 已提交
223 224 225 226 227 228 229 230 231
{
	struct subchannel *sch = to_subchannel(dev);
	struct pmcw *pmcw = &sch->schib.pmcw;

	return sprintf (buf, "%02x %02x %02x\n",
			pmcw->pim, pmcw->pam, pmcw->pom);
}

static ssize_t
232
devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
L
Linus Torvalds 已提交
233 234 235 236 237 238 239 240 241 242 243 244
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_device_id *id = &(cdev->id);

	if (id->dev_type != 0)
		return sprintf(buf, "%04x/%02x\n",
				id->dev_type, id->dev_model);
	else
		return sprintf(buf, "n/a\n");
}

static ssize_t
245
cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
L
Linus Torvalds 已提交
246 247 248 249 250 251 252 253
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_device_id *id = &(cdev->id);

	return sprintf(buf, "%04x/%02x\n",
		       id->cu_type, id->cu_model);
}

254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270
static ssize_t
modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_device_id *id = &(cdev->id);
	int ret;

	ret = sprintf(buf, "ccw:t%04Xm%02x",
			id->cu_type, id->cu_model);
	if (id->dev_type != 0)
		ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
				id->dev_type, id->dev_model);
	else
		ret += sprintf(buf + ret, "dtdm\n");
	return ret;
}

L
Linus Torvalds 已提交
271
static ssize_t
272
online_show (struct device *dev, struct device_attribute *attr, char *buf)
L
Linus Torvalds 已提交
273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369
{
	struct ccw_device *cdev = to_ccwdev(dev);

	return sprintf(buf, cdev->online ? "1\n" : "0\n");
}

static void
ccw_device_remove_disconnected(struct ccw_device *cdev)
{
	struct subchannel *sch;
	/*
	 * Forced offline in disconnected state means
	 * 'throw away device'.
	 */
	sch = to_subchannel(cdev->dev.parent);
	device_unregister(&sch->dev);
	/* Reset intparm to zeroes. */
	sch->schib.pmcw.intparm = 0;
	cio_modify(sch);
	put_device(&sch->dev);
}

int
ccw_device_set_offline(struct ccw_device *cdev)
{
	int ret;

	if (!cdev)
		return -ENODEV;
	if (!cdev->online || !cdev->drv)
		return -EINVAL;

	if (cdev->drv->set_offline) {
		ret = cdev->drv->set_offline(cdev);
		if (ret != 0)
			return ret;
	}
	cdev->online = 0;
	spin_lock_irq(cdev->ccwlock);
	ret = ccw_device_offline(cdev);
	if (ret == -ENODEV) {
		if (cdev->private->state != DEV_STATE_NOT_OPER) {
			cdev->private->state = DEV_STATE_OFFLINE;
			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
		}
		spin_unlock_irq(cdev->ccwlock);
		return ret;
	}
	spin_unlock_irq(cdev->ccwlock);
	if (ret == 0)
		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
	else {
		pr_debug("ccw_device_offline returned %d, device %s\n",
			 ret, cdev->dev.bus_id);
		cdev->online = 1;
	}
 	return ret;
}

int
ccw_device_set_online(struct ccw_device *cdev)
{
	int ret;

	if (!cdev)
		return -ENODEV;
	if (cdev->online || !cdev->drv)
		return -EINVAL;

	spin_lock_irq(cdev->ccwlock);
	ret = ccw_device_online(cdev);
	spin_unlock_irq(cdev->ccwlock);
	if (ret == 0)
		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
	else {
		pr_debug("ccw_device_online returned %d, device %s\n",
			 ret, cdev->dev.bus_id);
		return ret;
	}
	if (cdev->private->state != DEV_STATE_ONLINE)
		return -ENODEV;
	if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
		cdev->online = 1;
		return 0;
	}
	spin_lock_irq(cdev->ccwlock);
	ret = ccw_device_offline(cdev);
	spin_unlock_irq(cdev->ccwlock);
	if (ret == 0)
		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
	else 
		pr_debug("ccw_device_offline returned %d, device %s\n",
			 ret, cdev->dev.bus_id);
	return (ret = 0) ? -ENODEV : ret;
}

static ssize_t
370
online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
L
Linus Torvalds 已提交
371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441
{
	struct ccw_device *cdev = to_ccwdev(dev);
	int i, force, ret;
	char *tmp;

	if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
		return -EAGAIN;

	if (cdev->drv && !try_module_get(cdev->drv->owner)) {
		atomic_set(&cdev->private->onoff, 0);
		return -EINVAL;
	}
	if (!strncmp(buf, "force\n", count)) {
		force = 1;
		i = 1;
	} else {
		force = 0;
		i = simple_strtoul(buf, &tmp, 16);
	}
	if (i == 1) {
		/* Do device recognition, if needed. */
		if (cdev->id.cu_type == 0) {
			ret = ccw_device_recognition(cdev);
			if (ret) {
				printk(KERN_WARNING"Couldn't start recognition "
				       "for device %s (ret=%d)\n",
				       cdev->dev.bus_id, ret);
				goto out;
			}
			wait_event(cdev->private->wait_q,
				   cdev->private->flags.recog_done);
		}
		if (cdev->drv && cdev->drv->set_online)
			ccw_device_set_online(cdev);
	} else if (i == 0) {
		if (cdev->private->state == DEV_STATE_DISCONNECTED)
			ccw_device_remove_disconnected(cdev);
		else if (cdev->drv && cdev->drv->set_offline)
			ccw_device_set_offline(cdev);
	}
	if (force && cdev->private->state == DEV_STATE_BOXED) {
		ret = ccw_device_stlck(cdev);
		if (ret) {
			printk(KERN_WARNING"ccw_device_stlck for device %s "
			       "returned %d!\n", cdev->dev.bus_id, ret);
			goto out;
		}
		/* Do device recognition, if needed. */
		if (cdev->id.cu_type == 0) {
			cdev->private->state = DEV_STATE_NOT_OPER;
			ret = ccw_device_recognition(cdev);
			if (ret) {
				printk(KERN_WARNING"Couldn't start recognition "
				       "for device %s (ret=%d)\n",
				       cdev->dev.bus_id, ret);
				goto out;
			}
			wait_event(cdev->private->wait_q,
				   cdev->private->flags.recog_done);
		}
		if (cdev->drv && cdev->drv->set_online)
			ccw_device_set_online(cdev);
	}
	out:
	if (cdev->drv)
		module_put(cdev->drv->owner);
	atomic_set(&cdev->private->onoff, 0);
	return count;
}

static ssize_t
442
available_show (struct device *dev, struct device_attribute *attr, char *buf)
L
Linus Torvalds 已提交
443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct subchannel *sch;

	switch (cdev->private->state) {
	case DEV_STATE_BOXED:
		return sprintf(buf, "boxed\n");
	case DEV_STATE_DISCONNECTED:
	case DEV_STATE_DISCONNECTED_SENSE_ID:
	case DEV_STATE_NOT_OPER:
		sch = to_subchannel(dev->parent);
		if (!sch->lpm)
			return sprintf(buf, "no path\n");
		else
			return sprintf(buf, "no device\n");
	default:
		/* All other states considered fine. */
		return sprintf(buf, "good\n");
	}
}

static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
468
static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
L
Linus Torvalds 已提交
469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
static DEVICE_ATTR(online, 0644, online_show, online_store);
extern struct device_attribute dev_attr_cmb_enable;
static DEVICE_ATTR(availability, 0444, available_show, NULL);

static struct attribute * subch_attrs[] = {
	&dev_attr_chpids.attr,
	&dev_attr_pimpampom.attr,
	NULL,
};

static struct attribute_group subch_attr_group = {
	.attrs = subch_attrs,
};

static inline int
subchannel_add_files (struct device *dev)
{
	return sysfs_create_group(&dev->kobj, &subch_attr_group);
}

static struct attribute * ccwdev_attrs[] = {
	&dev_attr_devtype.attr,
	&dev_attr_cutype.attr,
492
	&dev_attr_modalias.attr,
L
Linus Torvalds 已提交
493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535
	&dev_attr_online.attr,
	&dev_attr_cmb_enable.attr,
	&dev_attr_availability.attr,
	NULL,
};

static struct attribute_group ccwdev_attr_group = {
	.attrs = ccwdev_attrs,
};

static inline int
device_add_files (struct device *dev)
{
	return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
}

static inline void
device_remove_files(struct device *dev)
{
	sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
}

/* this is a simple abstraction for device_register that sets the
 * correct bus type and adds the bus specific files */
int
ccw_device_register(struct ccw_device *cdev)
{
	struct device *dev = &cdev->dev;
	int ret;

	dev->bus = &ccw_bus_type;

	if ((ret = device_add(dev)))
		return ret;

	set_bit(1, &cdev->private->registered);
	if ((ret = device_add_files(dev))) {
		if (test_and_clear_bit(1, &cdev->private->registered))
			device_del(dev);
	}
	return ret;
}

C
Cornelia Huck 已提交
536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
struct match_data {
	unsigned int  devno;
	struct ccw_device * sibling;
};

static int
match_devno(struct device * dev, void * data)
{
	struct match_data * d = (struct match_data *)data;
	struct ccw_device * cdev;

	cdev = to_ccwdev(dev);
	if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
	    (cdev->private->devno == d->devno) &&
	    (cdev != d->sibling)) {
		cdev->private->state = DEV_STATE_NOT_OPER;
		return 1;
	}
	return 0;
}

L
Linus Torvalds 已提交
557 558 559 560
static struct ccw_device *
get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
{
	struct device *dev;
C
Cornelia Huck 已提交
561 562 563 564
	struct match_data data = {
		.devno  = devno,
		.sibling = sibling,
	};
L
Linus Torvalds 已提交
565

566
	dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
L
Linus Torvalds 已提交
567

C
Cornelia Huck 已提交
568
	return dev ? to_ccwdev(dev) : NULL;
L
Linus Torvalds 已提交
569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671
}

static void
ccw_device_add_changed(void *data)
{

	struct ccw_device *cdev;

	cdev = (struct ccw_device *)data;
	if (device_add(&cdev->dev)) {
		put_device(&cdev->dev);
		return;
	}
	set_bit(1, &cdev->private->registered);
	if (device_add_files(&cdev->dev)) {
		if (test_and_clear_bit(1, &cdev->private->registered))
			device_unregister(&cdev->dev);
	}
}

extern int css_get_ssd_info(struct subchannel *sch);

void
ccw_device_do_unreg_rereg(void *data)
{
	struct ccw_device *cdev;
	struct subchannel *sch;
	int need_rename;

	cdev = (struct ccw_device *)data;
	sch = to_subchannel(cdev->dev.parent);
	if (cdev->private->devno != sch->schib.pmcw.dev) {
		/*
		 * The device number has changed. This is usually only when
		 * a device has been detached under VM and then re-appeared
		 * on another subchannel because of a different attachment
		 * order than before. Ideally, we should should just switch
		 * subchannels, but unfortunately, this is not possible with
		 * the current implementation.
		 * Instead, we search for the old subchannel for this device
		 * number and deregister so there are no collisions with the
		 * newly registered ccw_device.
		 * FIXME: Find another solution so the block layer doesn't
		 *        get possibly sick...
		 */
		struct ccw_device *other_cdev;

		need_rename = 1;
		other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
						      cdev);
		if (other_cdev) {
			struct subchannel *other_sch;

			other_sch = to_subchannel(other_cdev->dev.parent);
			if (get_device(&other_sch->dev)) {
				stsch(other_sch->irq, &other_sch->schib);
				if (other_sch->schib.pmcw.dnv) {
					other_sch->schib.pmcw.intparm = 0;
					cio_modify(other_sch);
				}
				device_unregister(&other_sch->dev);
			}
		}
		/* Update ssd info here. */
		css_get_ssd_info(sch);
		cdev->private->devno = sch->schib.pmcw.dev;
	} else
		need_rename = 0;
	device_remove_files(&cdev->dev);
	if (test_and_clear_bit(1, &cdev->private->registered))
		device_del(&cdev->dev);
	if (need_rename)
		snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
			  sch->schib.pmcw.dev);
	PREPARE_WORK(&cdev->private->kick_work,
		     ccw_device_add_changed, (void *)cdev);
	queue_work(ccw_device_work, &cdev->private->kick_work);
}

static void
ccw_device_release(struct device *dev)
{
	struct ccw_device *cdev;

	cdev = to_ccwdev(dev);
	kfree(cdev->private);
	kfree(cdev);
}

/*
 * Register recognized device.
 */
static void
io_subchannel_register(void *data)
{
	struct ccw_device *cdev;
	struct subchannel *sch;
	int ret;
	unsigned long flags;

	cdev = (struct ccw_device *) data;
	sch = to_subchannel(cdev->dev.parent);

C
Cornelia Huck 已提交
672
	if (klist_node_attached(&cdev->dev.knode_parent)) {
L
Linus Torvalds 已提交
673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
		bus_rescan_devices(&ccw_bus_type);
		goto out;
	}
	/* make it known to the system */
	ret = ccw_device_register(cdev);
	if (ret) {
		printk (KERN_WARNING "%s: could not register %s\n",
			__func__, cdev->dev.bus_id);
		put_device(&cdev->dev);
		spin_lock_irqsave(&sch->lock, flags);
		sch->dev.driver_data = NULL;
		spin_unlock_irqrestore(&sch->lock, flags);
		kfree (cdev->private);
		kfree (cdev);
		put_device(&sch->dev);
		if (atomic_dec_and_test(&ccw_device_init_count))
			wake_up(&ccw_device_init_wq);
		return;
	}

	ret = subchannel_add_files(cdev->dev.parent);
	if (ret)
		printk(KERN_WARNING "%s: could not add attributes to %s\n",
		       __func__, sch->dev.bus_id);
	put_device(&cdev->dev);
out:
	cdev->private->flags.recog_done = 1;
	put_device(&sch->dev);
	wake_up(&cdev->private->wait_q);
	if (atomic_dec_and_test(&ccw_device_init_count))
		wake_up(&ccw_device_init_wq);
}

void
ccw_device_call_sch_unregister(void *data)
{
	struct ccw_device *cdev = data;
	struct subchannel *sch;

	sch = to_subchannel(cdev->dev.parent);
	device_unregister(&sch->dev);
	/* Reset intparm to zeroes. */
	sch->schib.pmcw.intparm = 0;
	cio_modify(sch);
	put_device(&cdev->dev);
	put_device(&sch->dev);
}

/*
 * subchannel recognition done. Called from the state machine.
 */
void
io_subchannel_recog_done(struct ccw_device *cdev)
{
	struct subchannel *sch;

	if (css_init_done == 0) {
		cdev->private->flags.recog_done = 1;
		return;
	}
	switch (cdev->private->state) {
	case DEV_STATE_NOT_OPER:
		cdev->private->flags.recog_done = 1;
		/* Remove device found not operational. */
		if (!get_device(&cdev->dev))
			break;
		sch = to_subchannel(cdev->dev.parent);
		PREPARE_WORK(&cdev->private->kick_work,
			     ccw_device_call_sch_unregister, (void *) cdev);
		queue_work(slow_path_wq, &cdev->private->kick_work);
		if (atomic_dec_and_test(&ccw_device_init_count))
			wake_up(&ccw_device_init_wq);
		break;
	case DEV_STATE_BOXED:
		/* Device did not respond in time. */
	case DEV_STATE_OFFLINE:
		/* 
		 * We can't register the device in interrupt context so
		 * we schedule a work item.
		 */
		if (!get_device(&cdev->dev))
			break;
		PREPARE_WORK(&cdev->private->kick_work,
			     io_subchannel_register, (void *) cdev);
		queue_work(slow_path_wq, &cdev->private->kick_work);
		break;
	}
}

static int
io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
{
	int rc;
	struct ccw_device_private *priv;

	sch->dev.driver_data = cdev;
	sch->driver = &io_subchannel_driver;
	cdev->ccwlock = &sch->lock;
	/* Init private data. */
	priv = cdev->private;
	priv->devno = sch->schib.pmcw.dev;
	priv->irq = sch->irq;
	priv->state = DEV_STATE_NOT_OPER;
	INIT_LIST_HEAD(&priv->cmb_list);
	init_waitqueue_head(&priv->wait_q);
	init_timer(&priv->timer);

	/* Set an initial name for the device. */
	snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
		  sch->schib.pmcw.dev);

	/* Increase counter of devices currently in recognition. */
	atomic_inc(&ccw_device_init_count);

	/* Start async. device sensing. */
	spin_lock_irq(&sch->lock);
	rc = ccw_device_recognition(cdev);
	spin_unlock_irq(&sch->lock);
	if (rc) {
		if (atomic_dec_and_test(&ccw_device_init_count))
			wake_up(&ccw_device_init_wq);
	}
	return rc;
}

static int
io_subchannel_probe (struct device *pdev)
{
	struct subchannel *sch;
	struct ccw_device *cdev;
	int rc;
	unsigned long flags;

	sch = to_subchannel(pdev);
	if (sch->dev.driver_data) {
		/*
		 * This subchannel already has an associated ccw_device.
		 * Register it and exit. This happens for all early
		 * device, e.g. the console.
		 */
		cdev = sch->dev.driver_data;
		device_initialize(&cdev->dev);
		ccw_device_register(cdev);
		subchannel_add_files(&sch->dev);
		/*
		 * Check if the device is already online. If it is
		 * the reference count needs to be corrected
		 * (see ccw_device_online and css_init_done for the
		 * ugly details).
		 */
		if (cdev->private->state != DEV_STATE_NOT_OPER &&
		    cdev->private->state != DEV_STATE_OFFLINE &&
		    cdev->private->state != DEV_STATE_BOXED)
			get_device(&cdev->dev);
		return 0;
	}
	cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
	if (!cdev)
		return -ENOMEM;
	memset(cdev, 0, sizeof(struct ccw_device));
	cdev->private = kmalloc(sizeof(struct ccw_device_private), 
				GFP_KERNEL | GFP_DMA);
	if (!cdev->private) {
		kfree(cdev);
		return -ENOMEM;
	}
	memset(cdev->private, 0, sizeof(struct ccw_device_private));
	atomic_set(&cdev->private->onoff, 0);
	cdev->dev = (struct device) {
		.parent = pdev,
		.release = ccw_device_release,
	};
	INIT_LIST_HEAD(&cdev->private->kick_work.entry);
	/* Do first half of device_register. */
	device_initialize(&cdev->dev);

	if (!get_device(&sch->dev)) {
		if (cdev->dev.release)
			cdev->dev.release(&cdev->dev);
		return -ENODEV;
	}

	rc = io_subchannel_recog(cdev, to_subchannel(pdev));
	if (rc) {
		spin_lock_irqsave(&sch->lock, flags);
		sch->dev.driver_data = NULL;
		spin_unlock_irqrestore(&sch->lock, flags);
		if (cdev->dev.release)
			cdev->dev.release(&cdev->dev);
	}

	return rc;
}

static void
ccw_device_unregister(void *data)
{
	struct ccw_device *cdev;

	cdev = (struct ccw_device *)data;
	if (test_and_clear_bit(1, &cdev->private->registered))
		device_unregister(&cdev->dev);
	put_device(&cdev->dev);
}

static int
io_subchannel_remove (struct device *dev)
{
	struct ccw_device *cdev;
	unsigned long flags;

	if (!dev->driver_data)
		return 0;
	cdev = dev->driver_data;
	/* Set ccw device to not operational and drop reference. */
	spin_lock_irqsave(cdev->ccwlock, flags);
	dev->driver_data = NULL;
	cdev->private->state = DEV_STATE_NOT_OPER;
	spin_unlock_irqrestore(cdev->ccwlock, flags);
	/*
	 * Put unregistration on workqueue to avoid livelocks on the css bus
	 * semaphore.
	 */
	if (get_device(&cdev->dev)) {
		PREPARE_WORK(&cdev->private->kick_work,
			     ccw_device_unregister, (void *) cdev);
		queue_work(ccw_device_work, &cdev->private->kick_work);
	}
	return 0;
}

static int
io_subchannel_notify(struct device *dev, int event)
{
	struct ccw_device *cdev;

	cdev = dev->driver_data;
	if (!cdev)
		return 0;
	if (!cdev->drv)
		return 0;
	if (!cdev->online)
		return 0;
	return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
}

static void
io_subchannel_verify(struct device *dev)
{
	struct ccw_device *cdev;

	cdev = dev->driver_data;
	if (cdev)
		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
}

static void
io_subchannel_ioterm(struct device *dev)
{
	struct ccw_device *cdev;

	cdev = dev->driver_data;
	if (!cdev)
		return;
	cdev->private->state = DEV_STATE_CLEAR_VERIFY;
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-EIO));
}

static void
io_subchannel_shutdown(struct device *dev)
{
	struct subchannel *sch;
	struct ccw_device *cdev;
	int ret;

	sch = to_subchannel(dev);
	cdev = dev->driver_data;

	if (cio_is_console(sch->irq))
		return;
	if (!sch->schib.pmcw.ena)
		/* Nothing to do. */
		return;
	ret = cio_disable_subchannel(sch);
	if (ret != -EBUSY)
		/* Subchannel is disabled, we're done. */
		return;
	cdev->private->state = DEV_STATE_QUIESCE;
	if (cdev->handler)
		cdev->handler(cdev, cdev->private->intparm,
			      ERR_PTR(-EIO));
	ret = ccw_device_cancel_halt_clear(cdev);
	if (ret == -EBUSY) {
		ccw_device_set_timeout(cdev, HZ/10);
		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
	}
	cio_disable_subchannel(sch);
}

#ifdef CONFIG_CCW_CONSOLE
static struct ccw_device console_cdev;
static struct ccw_device_private console_private;
static int console_cdev_in_use;

static int
ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
{
	int rc;

	/* Initialize the ccw_device structure. */
	cdev->dev = (struct device) {
		.parent = &sch->dev,
	};
	/* Initialize the subchannel structure */
	sch->dev.parent = &css_bus_device;
	sch->dev.bus = &css_bus_type;

	rc = io_subchannel_recog(cdev, sch);
	if (rc)
		return rc;

	/* Now wait for the async. recognition to come to an end. */
	spin_lock_irq(cdev->ccwlock);
	while (!dev_fsm_final_state(cdev))
		wait_cons_dev();
	rc = -EIO;
	if (cdev->private->state != DEV_STATE_OFFLINE)
		goto out_unlock;
	ccw_device_online(cdev);
	while (!dev_fsm_final_state(cdev))
		wait_cons_dev();
	if (cdev->private->state != DEV_STATE_ONLINE)
		goto out_unlock;
	rc = 0;
out_unlock:
	spin_unlock_irq(cdev->ccwlock);
	return 0;
}

struct ccw_device *
ccw_device_probe_console(void)
{
	struct subchannel *sch;
	int ret;

	if (xchg(&console_cdev_in_use, 1) != 0)
		return NULL;
	sch = cio_probe_console();
	if (IS_ERR(sch)) {
		console_cdev_in_use = 0;
		return (void *) sch;
	}
	memset(&console_cdev, 0, sizeof(struct ccw_device));
	memset(&console_private, 0, sizeof(struct ccw_device_private));
	console_cdev.private = &console_private;
	ret = ccw_device_console_enable(&console_cdev, sch);
	if (ret) {
		cio_release_console();
		console_cdev_in_use = 0;
		return ERR_PTR(ret);
	}
	console_cdev.online = 1;
	return &console_cdev;
}
#endif

/*
 * get ccw_device matching the busid, but only if owned by cdrv
 */
C
Cornelia Huck 已提交
1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
static int
__ccwdev_check_busid(struct device *dev, void *id)
{
	char *bus_id;

	bus_id = (char *)id;

	return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
}


L
Linus Torvalds 已提交
1055 1056 1057
struct ccw_device *
get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
{
C
Cornelia Huck 已提交
1058
	struct device *dev;
L
Linus Torvalds 已提交
1059 1060 1061 1062
	struct device_driver *drv;

	drv = get_driver(&cdrv->driver);
	if (!drv)
C
Cornelia Huck 已提交
1063
		return NULL;
L
Linus Torvalds 已提交
1064

C
Cornelia Huck 已提交
1065 1066
	dev = driver_find_device(drv, NULL, (void *)bus_id,
				 __ccwdev_check_busid);
L
Linus Torvalds 已提交
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
	put_driver(drv);

	return dev ? to_ccwdev(dev) : 0;
}

/************************** device driver handling ************************/

/* This is the implementation of the ccw_driver class. The probe, remove
 * and release methods are initially very similar to the device_driver
 * implementations, with the difference that they have ccw_device
 * arguments.
 *
 * A ccw driver also contains the information that is needed for
 * device matching.
 */
static int
ccw_device_probe (struct device *dev)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
	int ret;

	cdev->drv = cdrv; /* to let the driver call _set_online */

	ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;

	if (ret) {
		cdev->drv = 0;
		return ret;
	}

	return 0;
}

static int
ccw_device_remove (struct device *dev)
{
	struct ccw_device *cdev = to_ccwdev(dev);
	struct ccw_driver *cdrv = cdev->drv;
	int ret;

	pr_debug("removing device %s\n", cdev->dev.bus_id);
	if (cdrv->remove)
		cdrv->remove(cdev);
	if (cdev->online) {
		cdev->online = 0;
		spin_lock_irq(cdev->ccwlock);
		ret = ccw_device_offline(cdev);
		spin_unlock_irq(cdev->ccwlock);
		if (ret == 0)
			wait_event(cdev->private->wait_q,
				   dev_fsm_final_state(cdev));
		else
			//FIXME: we can't fail!
			pr_debug("ccw_device_offline returned %d, device %s\n",
				 ret, cdev->dev.bus_id);
	}
	ccw_device_set_timeout(cdev, 0);
	cdev->drv = 0;
	return 0;
}

int
ccw_driver_register (struct ccw_driver *cdriver)
{
	struct device_driver *drv = &cdriver->driver;

	drv->bus = &ccw_bus_type;
	drv->name = cdriver->name;
	drv->probe = ccw_device_probe;
	drv->remove = ccw_device_remove;

	return driver_register(drv);
}

void
ccw_driver_unregister (struct ccw_driver *cdriver)
{
	driver_unregister(&cdriver->driver);
}

MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_online);
EXPORT_SYMBOL(ccw_device_set_offline);
EXPORT_SYMBOL(ccw_driver_register);
EXPORT_SYMBOL(ccw_driver_unregister);
EXPORT_SYMBOL(get_ccwdev_by_busid);
EXPORT_SYMBOL(ccw_bus_type);
EXPORT_SYMBOL(ccw_device_work);
EXPORT_SYMBOL(ccw_device_notify_work);