2 * Linux driver for System z and s390 unit record devices
3 * (z/VM virtual punch, reader, printer)
5 * Copyright IBM Corp. 2001, 2007
6 * Authors: Malcolm Beattie <beattiem@uk.ibm.com>
7 * Michael Holzheu <holzheu@de.ibm.com>
8 * Frank Munzert <munzert@de.ibm.com>
11 #include <linux/cdev.h>
13 #include <asm/uaccess.h>
15 #include <asm/ccwdev.h>
16 #include <asm/debug.h>
24 * Unit record device support is implemented as a character device driver.
25 * We can fit at least 16 bits into a device minor number and use the
26 * simple method of mapping a character device number with minor abcd
27 * to the unit record device with devno abcd.
28 * I/O to virtual unit record devices is handled as follows:
29 * Reads: Diagnose code 0x14 (input spool file manipulation)
30 * is used to read spool data page-wise.
31 * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
32 * is available by reading sysfs attr reclen. Each write() to the device
33 * must specify an integral multiple (maximal 511) of reclen.
36 static char ur_banner[] = "z/VM virtual unit record device driver";
38 MODULE_AUTHOR("IBM Corporation");
39 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
40 MODULE_LICENSE("GPL");
42 #define PRINTK_HEADER "vmur: "
44 static dev_t ur_first_dev_maj_min;
45 static struct class *vmur_class;
46 static struct debug_info *vmur_dbf;
48 /* We put the device's record length (for writes) in the driver_info field */
49 static struct ccw_device_id ur_ids[] = {
50 { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
51 { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
55 MODULE_DEVICE_TABLE(ccw, ur_ids);
57 static int ur_probe(struct ccw_device *cdev);
58 static void ur_remove(struct ccw_device *cdev);
59 static int ur_set_online(struct ccw_device *cdev);
60 static int ur_set_offline(struct ccw_device *cdev);
62 static struct ccw_driver ur_driver = {
68 .set_online = ur_set_online,
69 .set_offline = ur_set_offline,
72 static DEFINE_MUTEX(vmur_mutex);
75 * Allocation, freeing, getting and putting of urdev structures
77 * Each ur device (urd) contains a reference to its corresponding ccw device
78 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
79 * ur device using the cdev->dev.driver_data pointer.
82 * - ur_probe gets a urd reference, ur_remove drops the reference
83 * (cdev->dev.driver_data)
84 * - ur_open gets a urd reference, ur_relase drops the reference
88 * - urdev_alloc get a cdev reference (urd->cdev)
89 * - urdev_free drops the cdev reference (urd->cdev)
91 * Setting and clearing of cdev->dev.driver_data is protected by the ccwdev lock
93 static struct urdev *urdev_alloc(struct ccw_device *cdev)
97 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
100 urd->reclen = cdev->id.driver_info;
101 ccw_device_get_id(cdev, &urd->dev_id);
102 mutex_init(&urd->io_mutex);
103 init_waitqueue_head(&urd->wait);
104 spin_lock_init(&urd->open_lock);
105 atomic_set(&urd->ref_count, 1);
107 get_device(&cdev->dev);
111 static void urdev_free(struct urdev *urd)
113 TRACE("urdev_free: %p\n", urd);
115 put_device(&urd->cdev->dev);
119 static void urdev_get(struct urdev *urd)
121 atomic_inc(&urd->ref_count);
124 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
129 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
130 urd = cdev->dev.driver_data;
133 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
137 static struct urdev *urdev_get_from_devno(u16 devno)
140 struct ccw_device *cdev;
143 sprintf(bus_id, "0.0.%04x", devno);
144 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
147 urd = urdev_get_from_cdev(cdev);
148 put_device(&cdev->dev);
152 static void urdev_put(struct urdev *urd)
154 if (atomic_dec_and_test(&urd->ref_count))
159 * Low-level functions to do I/O to a ur device.
165 * alloc_chan_prog allocates and builds the channel program
166 * free_chan_prog frees memory of the channel program
168 * do_ur_io issues the channel program to the device and blocks waiting
169 * on a completion event it publishes at urd->io_done. The function
170 * serialises itself on the device's mutex so that only one I/O
171 * is issued at a time (and that I/O is synchronous).
173 * ur_int_handler catches the "I/O done" interrupt, writes the
174 * subchannel status word into the scsw member of the urdev structure
175 * and complete()s the io_done to wake the waiting do_ur_io.
177 * The caller of do_ur_io is responsible for kfree()ing the channel program
178 * address pointer that alloc_chan_prog returned.
181 static void free_chan_prog(struct ccw1 *cpa)
183 struct ccw1 *ptr = cpa;
186 kfree((void *)(addr_t) ptr->cda);
194 * The channel program we use is write commands chained together
195 * with a final NOP CCW command-chained on (which ensures that CE and DE
196 * are presented together in a single interrupt instead of as separate
197 * interrupts unless an incorrect length indication kicks in first). The
198 * data length in each CCW is reclen.
200 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
207 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
210 * We chain a NOP onto the writes to force CE+DE together.
211 * That means we allocate room for CCWs to cover count/reclen
212 * records plus a NOP.
214 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
215 GFP_KERNEL | GFP_DMA);
217 return ERR_PTR(-ENOMEM);
219 for (i = 0; i < rec_count; i++) {
220 cpa[i].cmd_code = WRITE_CCW_CMD;
221 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
222 cpa[i].count = reclen;
223 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
226 return ERR_PTR(-ENOMEM);
228 cpa[i].cda = (u32)(addr_t) kbuf;
229 if (copy_from_user(kbuf, ubuf, reclen)) {
231 return ERR_PTR(-EFAULT);
235 /* The following NOP CCW forces CE+DE to be presented together */
236 cpa[i].cmd_code = CCW_CMD_NOOP;
240 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
243 struct ccw_device *cdev = urd->cdev;
244 DECLARE_COMPLETION_ONSTACK(event);
246 TRACE("do_ur_io: cpa=%p\n", cpa);
248 rc = mutex_lock_interruptible(&urd->io_mutex);
252 urd->io_done = &event;
254 spin_lock_irq(get_ccwdev_lock(cdev));
255 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
256 spin_unlock_irq(get_ccwdev_lock(cdev));
258 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
262 wait_for_completion(&event);
263 TRACE("do_ur_io: I/O complete\n");
267 mutex_unlock(&urd->io_mutex);
272 * ur interrupt handler, called from the ccw_device layer
274 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
279 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
280 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
281 irb->scsw.cmd.count);
284 TRACE("ur_int_handler: unsolicited interrupt\n");
287 urd = cdev->dev.driver_data;
289 /* On special conditions irb is an error pointer */
291 urd->io_request_rc = PTR_ERR(irb);
292 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
293 urd->io_request_rc = 0;
295 urd->io_request_rc = -EIO;
297 complete(urd->io_done);
301 * reclen sysfs attribute - The record length to be used for write CCWs
303 static ssize_t ur_attr_reclen_show(struct device *dev,
304 struct device_attribute *attr, char *buf)
309 urd = urdev_get_from_cdev(to_ccwdev(dev));
312 rc = sprintf(buf, "%zu\n", urd->reclen);
317 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
319 static int ur_create_attributes(struct device *dev)
321 return device_create_file(dev, &dev_attr_reclen);
324 static void ur_remove_attributes(struct device *dev)
326 device_remove_file(dev, &dev_attr_reclen);
330 * diagnose code 0x210 - retrieve device information
331 * cc=0 normal completion, we have a real device
332 * cc=1 CP paging error
333 * cc=2 The virtual device exists, but is not associated with a real device
334 * cc=3 Invalid device address, or the virtual device does not exist
336 static int get_urd_class(struct urdev *urd)
338 static struct diag210 ur_diag210;
341 ur_diag210.vrdcdvno = urd->dev_id.devno;
342 ur_diag210.vrdclen = sizeof(struct diag210);
344 cc = diag210(&ur_diag210);
349 return ur_diag210.vrdcvcla; /* virtual device class */
358 * Allocation and freeing of urfile structures
360 static struct urfile *urfile_alloc(struct urdev *urd)
364 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
369 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
375 static void urfile_free(struct urfile *urf)
377 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
382 * The fops implementation of the character device driver
384 static ssize_t do_write(struct urdev *urd, const char __user *udata,
385 size_t count, size_t reclen, loff_t *ppos)
390 cpa = alloc_chan_prog(udata, count / reclen, reclen);
394 rc = do_ur_io(urd, cpa);
398 if (urd->io_request_rc) {
399 rc = urd->io_request_rc;
410 static ssize_t ur_write(struct file *file, const char __user *udata,
411 size_t count, loff_t *ppos)
413 struct urfile *urf = file->private_data;
415 TRACE("ur_write: count=%zu\n", count);
420 if (count % urf->dev_reclen)
421 return -EINVAL; /* count must be a multiple of reclen */
423 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
424 count = urf->dev_reclen * MAX_RECS_PER_IO;
426 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
430 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
432 * cc=0 normal completion
433 * cc=2 no file active on the virtual reader or device not ready
434 * cc=3 record specified is beyond EOF
436 static int diag_position_to_record(int devno, int record)
440 cc = diag14(record, devno, 0x28);
447 return -ENODATA; /* position beyond end of file */
454 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
455 * cc=0 normal completion
457 * cc=2 no file active on the virtual reader, and no file eligible
458 * cc=3 file already active on the virtual reader or specified virtual
459 * reader does not exist or is not a reader
461 static int diag_read_file(int devno, char *buf)
465 cc = diag14((unsigned long) buf, devno, 0x00);
478 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
481 size_t len, copied, res;
487 urd = ((struct urfile *) file->private_data)->urd;
488 reclen = ((struct urfile *) file->private_data)->file_reclen;
490 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
496 len = min((size_t) PAGE_SIZE, count);
497 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
502 res = (size_t) (*offs % PAGE_SIZE);
504 rc = diag_read_file(urd->dev_id.devno, buf);
505 if (rc == -ENODATA) {
510 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
511 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
512 len = min(count - copied, PAGE_SIZE - res);
513 if (copy_to_user(ubuf + copied, buf + res, len)) {
519 } while (copied != count);
524 free_page((unsigned long) buf);
528 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
534 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
539 urd = ((struct urfile *) file->private_data)->urd;
540 rc = mutex_lock_interruptible(&urd->io_mutex);
543 rc = diag14_read(file, ubuf, count, offs);
544 mutex_unlock(&urd->io_mutex);
549 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
550 * cc=0 normal completion
551 * cc=1 no files on reader queue or no subsequent file
552 * cc=2 spid specified is invalid
554 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
558 cc = diag14((unsigned long) buf, spid, 0xfff);
567 static int verify_uri_device(struct urdev *urd)
569 struct file_control_block *fcb;
573 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
577 /* check for empty reader device (beginning of chain) */
578 rc = diag_read_next_file_info(fcb, 0);
582 /* if file is in hold status, we do not read it */
583 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
588 /* open file on virtual reader */
589 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
594 rc = diag_read_file(urd->dev_id.devno, buf);
595 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
598 /* check if the file on top of the queue is open now */
599 rc = diag_read_next_file_info(fcb, 0);
602 if (!(fcb->file_stat & FLG_IN_USE)) {
609 free_page((unsigned long) buf);
615 static int verify_device(struct urdev *urd)
617 switch (urd->class) {
619 return 0; /* no check needed here */
621 return verify_uri_device(urd);
627 static int get_uri_file_reclen(struct urdev *urd)
629 struct file_control_block *fcb;
632 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
635 rc = diag_read_next_file_info(fcb, 0);
638 if (fcb->file_stat & FLG_CP_DUMP)
648 static int get_file_reclen(struct urdev *urd)
650 switch (urd->class) {
654 return get_uri_file_reclen(urd);
660 static int ur_open(struct inode *inode, struct file *file)
665 unsigned short accmode;
668 accmode = file->f_flags & O_ACCMODE;
670 if (accmode == O_RDWR)
674 * We treat the minor number as the devno of the ur device
675 * to find in the driver tree.
677 devno = MINOR(file->f_dentry->d_inode->i_rdev);
679 urd = urdev_get_from_devno(devno);
683 spin_lock(&urd->open_lock);
684 while (urd->open_flag) {
685 spin_unlock(&urd->open_lock);
686 if (file->f_flags & O_NONBLOCK) {
690 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
694 spin_lock(&urd->open_lock);
697 spin_unlock(&urd->open_lock);
701 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
702 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
703 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
708 rc = verify_device(urd);
712 urf = urfile_alloc(urd);
718 urf->dev_reclen = urd->reclen;
719 rc = get_file_reclen(urd);
721 goto fail_urfile_free;
722 urf->file_reclen = rc;
723 file->private_data = urf;
729 spin_lock(&urd->open_lock);
731 spin_unlock(&urd->open_lock);
737 static int ur_release(struct inode *inode, struct file *file)
739 struct urfile *urf = file->private_data;
741 TRACE("ur_release\n");
742 spin_lock(&urf->urd->open_lock);
743 urf->urd->open_flag--;
744 spin_unlock(&urf->urd->open_lock);
745 wake_up_interruptible(&urf->urd->wait);
751 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
755 if ((file->f_flags & O_ACCMODE) != O_RDONLY)
756 return -ESPIPE; /* seek allowed only for reader */
757 if (offset % PAGE_SIZE)
758 return -ESPIPE; /* only multiples of 4K allowed */
760 case 0: /* SEEK_SET */
763 case 1: /* SEEK_CUR */
764 newpos = file->f_pos + offset;
769 file->f_pos = newpos;
773 static const struct file_operations ur_fops = {
774 .owner = THIS_MODULE,
776 .release = ur_release,
783 * ccw_device infrastructure:
784 * ur_probe creates the struct urdev (with refcount = 1), the device
785 * attributes, sets up the interrupt handler and validates the virtual
786 * unit record device.
787 * ur_remove removes the device attributes and drops the reference to
790 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
791 * by the vmur_mutex lock.
793 * urd->char_device is used as indication that the online function has
794 * been completed successfully.
796 static int ur_probe(struct ccw_device *cdev)
801 TRACE("ur_probe: cdev=%p\n", cdev);
803 mutex_lock(&vmur_mutex);
804 urd = urdev_alloc(cdev);
810 rc = ur_create_attributes(&cdev->dev);
815 cdev->handler = ur_int_handler;
817 /* validate virtual unit record device */
818 urd->class = get_urd_class(urd);
819 if (urd->class < 0) {
821 goto fail_remove_attr;
823 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
825 goto fail_remove_attr;
827 spin_lock_irq(get_ccwdev_lock(cdev));
828 cdev->dev.driver_data = urd;
829 spin_unlock_irq(get_ccwdev_lock(cdev));
831 mutex_unlock(&vmur_mutex);
835 ur_remove_attributes(&cdev->dev);
839 mutex_unlock(&vmur_mutex);
843 static int ur_set_online(struct ccw_device *cdev)
846 int minor, major, rc;
849 TRACE("ur_set_online: cdev=%p\n", cdev);
851 mutex_lock(&vmur_mutex);
852 urd = urdev_get_from_cdev(cdev);
854 /* ur_remove already deleted our urd */
859 if (urd->char_device) {
860 /* Another ur_set_online was faster */
865 minor = urd->dev_id.devno;
866 major = MAJOR(ur_first_dev_maj_min);
868 urd->char_device = cdev_alloc();
869 if (!urd->char_device) {
874 cdev_init(urd->char_device, &ur_fops);
875 urd->char_device->dev = MKDEV(major, minor);
876 urd->char_device->owner = ur_fops.owner;
878 rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
881 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
882 if (urd->class == DEV_CLASS_UR_I)
883 sprintf(node_id, "vmrdr-%s", cdev->dev.bus_id);
884 if (urd->class == DEV_CLASS_UR_O)
885 sprintf(node_id, "vmpun-%s", cdev->dev.bus_id);
886 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
887 sprintf(node_id, "vmprt-%s", cdev->dev.bus_id);
893 urd->device = device_create(vmur_class, NULL, urd->char_device->dev,
895 if (IS_ERR(urd->device)) {
896 rc = PTR_ERR(urd->device);
897 TRACE("ur_set_online: device_create rc=%d\n", rc);
901 mutex_unlock(&vmur_mutex);
905 cdev_del(urd->char_device);
906 urd->char_device = NULL;
910 mutex_unlock(&vmur_mutex);
914 static int ur_set_offline_force(struct ccw_device *cdev, int force)
919 TRACE("ur_set_offline: cdev=%p\n", cdev);
920 urd = urdev_get_from_cdev(cdev);
922 /* ur_remove already deleted our urd */
924 if (!urd->char_device) {
925 /* Another ur_set_offline was faster */
929 if (!force && (atomic_read(&urd->ref_count) > 2)) {
930 /* There is still a user of urd (e.g. ur_open) */
931 TRACE("ur_set_offline: BUSY\n");
935 device_destroy(vmur_class, urd->char_device->dev);
936 cdev_del(urd->char_device);
937 urd->char_device = NULL;
945 static int ur_set_offline(struct ccw_device *cdev)
949 mutex_lock(&vmur_mutex);
950 rc = ur_set_offline_force(cdev, 0);
951 mutex_unlock(&vmur_mutex);
955 static void ur_remove(struct ccw_device *cdev)
959 TRACE("ur_remove\n");
961 mutex_lock(&vmur_mutex);
964 ur_set_offline_force(cdev, 1);
965 ur_remove_attributes(&cdev->dev);
967 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
968 urdev_put(cdev->dev.driver_data);
969 cdev->dev.driver_data = NULL;
970 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
972 mutex_unlock(&vmur_mutex);
976 * Module initialisation and cleanup
978 static int __init ur_init(void)
983 if (!MACHINE_IS_VM) {
984 PRINT_ERR("%s is only available under z/VM.\n", ur_banner);
988 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
991 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
995 debug_set_level(vmur_dbf, 6);
997 rc = ccw_driver_register(&ur_driver);
1001 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1003 PRINT_ERR("alloc_chrdev_region failed: err = %d\n", rc);
1004 goto fail_unregister_driver;
1006 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1008 vmur_class = class_create(THIS_MODULE, "vmur");
1009 if (IS_ERR(vmur_class)) {
1010 rc = PTR_ERR(vmur_class);
1011 goto fail_unregister_region;
1013 PRINT_INFO("%s loaded.\n", ur_banner);
1016 fail_unregister_region:
1017 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1018 fail_unregister_driver:
1019 ccw_driver_unregister(&ur_driver);
1021 debug_unregister(vmur_dbf);
1025 static void __exit ur_exit(void)
1027 class_destroy(vmur_class);
1028 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1029 ccw_driver_unregister(&ur_driver);
1030 debug_unregister(vmur_dbf);
1031 PRINT_INFO("%s unloaded.\n", ur_banner);
1034 module_init(ur_init);
1035 module_exit(ur_exit);