2 * Linux driver for System z and s390 unit record devices
3 * (z/VM virtual punch, reader, printer)
5 * Copyright IBM Corp. 2001, 2009
6 * Authors: Malcolm Beattie <beattiem@uk.ibm.com>
7 * Michael Holzheu <holzheu@de.ibm.com>
8 * Frank Munzert <munzert@de.ibm.com>
11 #define KMSG_COMPONENT "vmur"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/cdev.h>
15 #include <linux/slab.h>
17 #include <asm/uaccess.h>
19 #include <asm/ccwdev.h>
20 #include <asm/debug.h>
28 * Unit record device support is implemented as a character device driver.
29 * We can fit at least 16 bits into a device minor number and use the
30 * simple method of mapping a character device number with minor abcd
31 * to the unit record device with devno abcd.
32 * I/O to virtual unit record devices is handled as follows:
33 * Reads: Diagnose code 0x14 (input spool file manipulation)
34 * is used to read spool data page-wise.
35 * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
36 * is available by reading sysfs attr reclen. Each write() to the device
37 * must specify an integral multiple (maximal 511) of reclen.
40 static char ur_banner[] = "z/VM virtual unit record device driver";
42 MODULE_AUTHOR("IBM Corporation");
43 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
44 MODULE_LICENSE("GPL");
46 static dev_t ur_first_dev_maj_min;
47 static struct class *vmur_class;
48 static struct debug_info *vmur_dbf;
50 /* We put the device's record length (for writes) in the driver_info field */
51 static struct ccw_device_id ur_ids[] = {
52 { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
53 { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
57 MODULE_DEVICE_TABLE(ccw, ur_ids);
59 static int ur_probe(struct ccw_device *cdev);
60 static void ur_remove(struct ccw_device *cdev);
61 static int ur_set_online(struct ccw_device *cdev);
62 static int ur_set_offline(struct ccw_device *cdev);
63 static int ur_pm_suspend(struct ccw_device *cdev);
65 static struct ccw_driver ur_driver = {
73 .set_online = ur_set_online,
74 .set_offline = ur_set_offline,
75 .freeze = ur_pm_suspend,
76 .int_class = IOINT_VMR,
79 static DEFINE_MUTEX(vmur_mutex);
82 * Allocation, freeing, getting and putting of urdev structures
84 * Each ur device (urd) contains a reference to its corresponding ccw device
85 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
86 * ur device using dev_get_drvdata(&cdev->dev) pointer.
89 * - ur_probe gets a urd reference, ur_remove drops the reference
90 * dev_get_drvdata(&cdev->dev)
91 * - ur_open gets a urd reference, ur_relase drops the reference
95 * - urdev_alloc get a cdev reference (urd->cdev)
96 * - urdev_free drops the cdev reference (urd->cdev)
98 * Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock
100 static struct urdev *urdev_alloc(struct ccw_device *cdev)
104 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
107 urd->reclen = cdev->id.driver_info;
108 ccw_device_get_id(cdev, &urd->dev_id);
109 mutex_init(&urd->io_mutex);
110 init_waitqueue_head(&urd->wait);
111 spin_lock_init(&urd->open_lock);
112 atomic_set(&urd->ref_count, 1);
114 get_device(&cdev->dev);
118 static void urdev_free(struct urdev *urd)
120 TRACE("urdev_free: %p\n", urd);
122 put_device(&urd->cdev->dev);
126 static void urdev_get(struct urdev *urd)
128 atomic_inc(&urd->ref_count);
131 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
136 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
137 urd = dev_get_drvdata(&cdev->dev);
140 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
144 static struct urdev *urdev_get_from_devno(u16 devno)
147 struct ccw_device *cdev;
150 sprintf(bus_id, "0.0.%04x", devno);
151 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
154 urd = urdev_get_from_cdev(cdev);
155 put_device(&cdev->dev);
159 static void urdev_put(struct urdev *urd)
161 if (atomic_dec_and_test(&urd->ref_count))
166 * State and contents of ur devices can be changed by class D users issuing
167 * CP commands such as PURGE or TRANSFER, while the Linux guest is suspended.
168 * Also the Linux guest might be logged off, which causes all active spool
169 * files to be closed.
170 * So we cannot guarantee that spool files are still the same when the Linux
171 * guest is resumed. In order to avoid unpredictable results at resume time
172 * we simply refuse to suspend if a ur device node is open.
174 static int ur_pm_suspend(struct ccw_device *cdev)
176 struct urdev *urd = dev_get_drvdata(&cdev->dev);
178 TRACE("ur_pm_suspend: cdev=%p\n", cdev);
179 if (urd->open_flag) {
180 pr_err("Unit record device %s is busy, %s refusing to "
181 "suspend.\n", dev_name(&cdev->dev), ur_banner);
188 * Low-level functions to do I/O to a ur device.
194 * alloc_chan_prog allocates and builds the channel program
195 * free_chan_prog frees memory of the channel program
197 * do_ur_io issues the channel program to the device and blocks waiting
198 * on a completion event it publishes at urd->io_done. The function
199 * serialises itself on the device's mutex so that only one I/O
200 * is issued at a time (and that I/O is synchronous).
202 * ur_int_handler catches the "I/O done" interrupt, writes the
203 * subchannel status word into the scsw member of the urdev structure
204 * and complete()s the io_done to wake the waiting do_ur_io.
206 * The caller of do_ur_io is responsible for kfree()ing the channel program
207 * address pointer that alloc_chan_prog returned.
210 static void free_chan_prog(struct ccw1 *cpa)
212 struct ccw1 *ptr = cpa;
215 kfree((void *)(addr_t) ptr->cda);
223 * The channel program we use is write commands chained together
224 * with a final NOP CCW command-chained on (which ensures that CE and DE
225 * are presented together in a single interrupt instead of as separate
226 * interrupts unless an incorrect length indication kicks in first). The
227 * data length in each CCW is reclen.
229 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
236 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
239 * We chain a NOP onto the writes to force CE+DE together.
240 * That means we allocate room for CCWs to cover count/reclen
241 * records plus a NOP.
243 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
244 GFP_KERNEL | GFP_DMA);
246 return ERR_PTR(-ENOMEM);
248 for (i = 0; i < rec_count; i++) {
249 cpa[i].cmd_code = WRITE_CCW_CMD;
250 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
251 cpa[i].count = reclen;
252 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
255 return ERR_PTR(-ENOMEM);
257 cpa[i].cda = (u32)(addr_t) kbuf;
258 if (copy_from_user(kbuf, ubuf, reclen)) {
260 return ERR_PTR(-EFAULT);
264 /* The following NOP CCW forces CE+DE to be presented together */
265 cpa[i].cmd_code = CCW_CMD_NOOP;
269 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
272 struct ccw_device *cdev = urd->cdev;
273 DECLARE_COMPLETION_ONSTACK(event);
275 TRACE("do_ur_io: cpa=%p\n", cpa);
277 rc = mutex_lock_interruptible(&urd->io_mutex);
281 urd->io_done = &event;
283 spin_lock_irq(get_ccwdev_lock(cdev));
284 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
285 spin_unlock_irq(get_ccwdev_lock(cdev));
287 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
291 wait_for_completion(&event);
292 TRACE("do_ur_io: I/O complete\n");
296 mutex_unlock(&urd->io_mutex);
301 * ur interrupt handler, called from the ccw_device layer
303 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
308 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
309 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
310 irb->scsw.cmd.count);
313 TRACE("ur_int_handler: unsolicited interrupt\n");
316 urd = dev_get_drvdata(&cdev->dev);
318 /* On special conditions irb is an error pointer */
320 urd->io_request_rc = PTR_ERR(irb);
321 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
322 urd->io_request_rc = 0;
324 urd->io_request_rc = -EIO;
326 complete(urd->io_done);
330 * reclen sysfs attribute - The record length to be used for write CCWs
332 static ssize_t ur_attr_reclen_show(struct device *dev,
333 struct device_attribute *attr, char *buf)
338 urd = urdev_get_from_cdev(to_ccwdev(dev));
341 rc = sprintf(buf, "%zu\n", urd->reclen);
346 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
348 static int ur_create_attributes(struct device *dev)
350 return device_create_file(dev, &dev_attr_reclen);
353 static void ur_remove_attributes(struct device *dev)
355 device_remove_file(dev, &dev_attr_reclen);
359 * diagnose code 0x210 - retrieve device information
360 * cc=0 normal completion, we have a real device
361 * cc=1 CP paging error
362 * cc=2 The virtual device exists, but is not associated with a real device
363 * cc=3 Invalid device address, or the virtual device does not exist
365 static int get_urd_class(struct urdev *urd)
367 static struct diag210 ur_diag210;
370 ur_diag210.vrdcdvno = urd->dev_id.devno;
371 ur_diag210.vrdclen = sizeof(struct diag210);
373 cc = diag210(&ur_diag210);
378 return ur_diag210.vrdcvcla; /* virtual device class */
387 * Allocation and freeing of urfile structures
389 static struct urfile *urfile_alloc(struct urdev *urd)
393 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
398 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
404 static void urfile_free(struct urfile *urf)
406 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
411 * The fops implementation of the character device driver
413 static ssize_t do_write(struct urdev *urd, const char __user *udata,
414 size_t count, size_t reclen, loff_t *ppos)
419 cpa = alloc_chan_prog(udata, count / reclen, reclen);
423 rc = do_ur_io(urd, cpa);
427 if (urd->io_request_rc) {
428 rc = urd->io_request_rc;
439 static ssize_t ur_write(struct file *file, const char __user *udata,
440 size_t count, loff_t *ppos)
442 struct urfile *urf = file->private_data;
444 TRACE("ur_write: count=%zu\n", count);
449 if (count % urf->dev_reclen)
450 return -EINVAL; /* count must be a multiple of reclen */
452 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
453 count = urf->dev_reclen * MAX_RECS_PER_IO;
455 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
459 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
461 * cc=0 normal completion
462 * cc=2 no file active on the virtual reader or device not ready
463 * cc=3 record specified is beyond EOF
465 static int diag_position_to_record(int devno, int record)
469 cc = diag14(record, devno, 0x28);
476 return -ENODATA; /* position beyond end of file */
483 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
484 * cc=0 normal completion
486 * cc=2 no file active on the virtual reader, and no file eligible
487 * cc=3 file already active on the virtual reader or specified virtual
488 * reader does not exist or is not a reader
490 static int diag_read_file(int devno, char *buf)
494 cc = diag14((unsigned long) buf, devno, 0x00);
507 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
510 size_t len, copied, res;
516 urd = ((struct urfile *) file->private_data)->urd;
517 reclen = ((struct urfile *) file->private_data)->file_reclen;
519 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
525 len = min((size_t) PAGE_SIZE, count);
526 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
531 res = (size_t) (*offs % PAGE_SIZE);
533 rc = diag_read_file(urd->dev_id.devno, buf);
534 if (rc == -ENODATA) {
539 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
540 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
541 len = min(count - copied, PAGE_SIZE - res);
542 if (copy_to_user(ubuf + copied, buf + res, len)) {
548 } while (copied != count);
553 free_page((unsigned long) buf);
557 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
563 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
568 urd = ((struct urfile *) file->private_data)->urd;
569 rc = mutex_lock_interruptible(&urd->io_mutex);
572 rc = diag14_read(file, ubuf, count, offs);
573 mutex_unlock(&urd->io_mutex);
578 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
579 * cc=0 normal completion
580 * cc=1 no files on reader queue or no subsequent file
581 * cc=2 spid specified is invalid
583 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
587 cc = diag14((unsigned long) buf, spid, 0xfff);
596 static int verify_uri_device(struct urdev *urd)
598 struct file_control_block *fcb;
602 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
606 /* check for empty reader device (beginning of chain) */
607 rc = diag_read_next_file_info(fcb, 0);
611 /* if file is in hold status, we do not read it */
612 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
617 /* open file on virtual reader */
618 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
623 rc = diag_read_file(urd->dev_id.devno, buf);
624 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
627 /* check if the file on top of the queue is open now */
628 rc = diag_read_next_file_info(fcb, 0);
631 if (!(fcb->file_stat & FLG_IN_USE)) {
638 free_page((unsigned long) buf);
644 static int verify_device(struct urdev *urd)
646 switch (urd->class) {
648 return 0; /* no check needed here */
650 return verify_uri_device(urd);
656 static int get_uri_file_reclen(struct urdev *urd)
658 struct file_control_block *fcb;
661 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
664 rc = diag_read_next_file_info(fcb, 0);
667 if (fcb->file_stat & FLG_CP_DUMP)
677 static int get_file_reclen(struct urdev *urd)
679 switch (urd->class) {
683 return get_uri_file_reclen(urd);
689 static int ur_open(struct inode *inode, struct file *file)
694 unsigned short accmode;
697 accmode = file->f_flags & O_ACCMODE;
699 if (accmode == O_RDWR)
702 * We treat the minor number as the devno of the ur device
703 * to find in the driver tree.
705 devno = MINOR(file->f_dentry->d_inode->i_rdev);
707 urd = urdev_get_from_devno(devno);
713 spin_lock(&urd->open_lock);
714 while (urd->open_flag) {
715 spin_unlock(&urd->open_lock);
716 if (file->f_flags & O_NONBLOCK) {
720 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
724 spin_lock(&urd->open_lock);
727 spin_unlock(&urd->open_lock);
731 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
732 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
733 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
738 rc = verify_device(urd);
742 urf = urfile_alloc(urd);
748 urf->dev_reclen = urd->reclen;
749 rc = get_file_reclen(urd);
751 goto fail_urfile_free;
752 urf->file_reclen = rc;
753 file->private_data = urf;
759 spin_lock(&urd->open_lock);
761 spin_unlock(&urd->open_lock);
768 static int ur_release(struct inode *inode, struct file *file)
770 struct urfile *urf = file->private_data;
772 TRACE("ur_release\n");
773 spin_lock(&urf->urd->open_lock);
774 urf->urd->open_flag--;
775 spin_unlock(&urf->urd->open_lock);
776 wake_up_interruptible(&urf->urd->wait);
782 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
786 if ((file->f_flags & O_ACCMODE) != O_RDONLY)
787 return -ESPIPE; /* seek allowed only for reader */
788 if (offset % PAGE_SIZE)
789 return -ESPIPE; /* only multiples of 4K allowed */
791 case 0: /* SEEK_SET */
794 case 1: /* SEEK_CUR */
795 newpos = file->f_pos + offset;
800 file->f_pos = newpos;
804 static const struct file_operations ur_fops = {
805 .owner = THIS_MODULE,
807 .release = ur_release,
814 * ccw_device infrastructure:
815 * ur_probe creates the struct urdev (with refcount = 1), the device
816 * attributes, sets up the interrupt handler and validates the virtual
817 * unit record device.
818 * ur_remove removes the device attributes and drops the reference to
821 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
822 * by the vmur_mutex lock.
824 * urd->char_device is used as indication that the online function has
825 * been completed successfully.
827 static int ur_probe(struct ccw_device *cdev)
832 TRACE("ur_probe: cdev=%p\n", cdev);
834 mutex_lock(&vmur_mutex);
835 urd = urdev_alloc(cdev);
841 rc = ur_create_attributes(&cdev->dev);
846 cdev->handler = ur_int_handler;
848 /* validate virtual unit record device */
849 urd->class = get_urd_class(urd);
850 if (urd->class < 0) {
852 goto fail_remove_attr;
854 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
856 goto fail_remove_attr;
858 spin_lock_irq(get_ccwdev_lock(cdev));
859 dev_set_drvdata(&cdev->dev, urd);
860 spin_unlock_irq(get_ccwdev_lock(cdev));
862 mutex_unlock(&vmur_mutex);
866 ur_remove_attributes(&cdev->dev);
870 mutex_unlock(&vmur_mutex);
874 static int ur_set_online(struct ccw_device *cdev)
877 int minor, major, rc;
880 TRACE("ur_set_online: cdev=%p\n", cdev);
882 mutex_lock(&vmur_mutex);
883 urd = urdev_get_from_cdev(cdev);
885 /* ur_remove already deleted our urd */
890 if (urd->char_device) {
891 /* Another ur_set_online was faster */
896 minor = urd->dev_id.devno;
897 major = MAJOR(ur_first_dev_maj_min);
899 urd->char_device = cdev_alloc();
900 if (!urd->char_device) {
905 cdev_init(urd->char_device, &ur_fops);
906 urd->char_device->dev = MKDEV(major, minor);
907 urd->char_device->owner = ur_fops.owner;
909 rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
912 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
913 if (urd->class == DEV_CLASS_UR_I)
914 sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
915 if (urd->class == DEV_CLASS_UR_O)
916 sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
917 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
918 sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
924 urd->device = device_create(vmur_class, NULL, urd->char_device->dev,
925 NULL, "%s", node_id);
926 if (IS_ERR(urd->device)) {
927 rc = PTR_ERR(urd->device);
928 TRACE("ur_set_online: device_create rc=%d\n", rc);
932 mutex_unlock(&vmur_mutex);
936 cdev_del(urd->char_device);
937 urd->char_device = NULL;
941 mutex_unlock(&vmur_mutex);
945 static int ur_set_offline_force(struct ccw_device *cdev, int force)
950 TRACE("ur_set_offline: cdev=%p\n", cdev);
951 urd = urdev_get_from_cdev(cdev);
953 /* ur_remove already deleted our urd */
955 if (!urd->char_device) {
956 /* Another ur_set_offline was faster */
960 if (!force && (atomic_read(&urd->ref_count) > 2)) {
961 /* There is still a user of urd (e.g. ur_open) */
962 TRACE("ur_set_offline: BUSY\n");
966 device_destroy(vmur_class, urd->char_device->dev);
967 cdev_del(urd->char_device);
968 urd->char_device = NULL;
976 static int ur_set_offline(struct ccw_device *cdev)
980 mutex_lock(&vmur_mutex);
981 rc = ur_set_offline_force(cdev, 0);
982 mutex_unlock(&vmur_mutex);
986 static void ur_remove(struct ccw_device *cdev)
990 TRACE("ur_remove\n");
992 mutex_lock(&vmur_mutex);
995 ur_set_offline_force(cdev, 1);
996 ur_remove_attributes(&cdev->dev);
998 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
999 urdev_put(dev_get_drvdata(&cdev->dev));
1000 dev_set_drvdata(&cdev->dev, NULL);
1001 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1003 mutex_unlock(&vmur_mutex);
1007 * Module initialisation and cleanup
1009 static int __init ur_init(void)
1014 if (!MACHINE_IS_VM) {
1015 pr_err("The %s cannot be loaded without z/VM\n",
1020 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
1023 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
1027 debug_set_level(vmur_dbf, 6);
1029 vmur_class = class_create(THIS_MODULE, "vmur");
1030 if (IS_ERR(vmur_class)) {
1031 rc = PTR_ERR(vmur_class);
1035 rc = ccw_driver_register(&ur_driver);
1037 goto fail_class_destroy;
1039 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1041 pr_err("Kernel function alloc_chrdev_region failed with "
1042 "error code %d\n", rc);
1043 goto fail_unregister_driver;
1045 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1047 pr_info("%s loaded.\n", ur_banner);
1050 fail_unregister_driver:
1051 ccw_driver_unregister(&ur_driver);
1053 class_destroy(vmur_class);
1055 debug_unregister(vmur_dbf);
1059 static void __exit ur_exit(void)
1061 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1062 ccw_driver_unregister(&ur_driver);
1063 class_destroy(vmur_class);
1064 debug_unregister(vmur_dbf);
1065 pr_info("%s unloaded.\n", ur_banner);
1068 module_init(ur_init);
1069 module_exit(ur_exit);