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>
16 #include <linux/smp_lock.h>
18 #include <asm/uaccess.h>
20 #include <asm/ccwdev.h>
21 #include <asm/debug.h>
29 * Unit record device support is implemented as a character device driver.
30 * We can fit at least 16 bits into a device minor number and use the
31 * simple method of mapping a character device number with minor abcd
32 * to the unit record device with devno abcd.
33 * I/O to virtual unit record devices is handled as follows:
34 * Reads: Diagnose code 0x14 (input spool file manipulation)
35 * is used to read spool data page-wise.
36 * Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
37 * is available by reading sysfs attr reclen. Each write() to the device
38 * must specify an integral multiple (maximal 511) of reclen.
41 static char ur_banner[] = "z/VM virtual unit record device driver";
43 MODULE_AUTHOR("IBM Corporation");
44 MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
45 MODULE_LICENSE("GPL");
47 static dev_t ur_first_dev_maj_min;
48 static struct class *vmur_class;
49 static struct debug_info *vmur_dbf;
51 /* We put the device's record length (for writes) in the driver_info field */
52 static struct ccw_device_id ur_ids[] = {
53 { CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
54 { CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
58 MODULE_DEVICE_TABLE(ccw, ur_ids);
60 static int ur_probe(struct ccw_device *cdev);
61 static void ur_remove(struct ccw_device *cdev);
62 static int ur_set_online(struct ccw_device *cdev);
63 static int ur_set_offline(struct ccw_device *cdev);
64 static int ur_pm_suspend(struct ccw_device *cdev);
66 static struct ccw_driver ur_driver = {
72 .set_online = ur_set_online,
73 .set_offline = ur_set_offline,
74 .freeze = ur_pm_suspend,
77 static DEFINE_MUTEX(vmur_mutex);
80 * Allocation, freeing, getting and putting of urdev structures
82 * Each ur device (urd) contains a reference to its corresponding ccw device
83 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
84 * ur device using dev_get_drvdata(&cdev->dev) pointer.
87 * - ur_probe gets a urd reference, ur_remove drops the reference
88 * dev_get_drvdata(&cdev->dev)
89 * - ur_open gets a urd reference, ur_relase drops the reference
93 * - urdev_alloc get a cdev reference (urd->cdev)
94 * - urdev_free drops the cdev reference (urd->cdev)
96 * Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock
98 static struct urdev *urdev_alloc(struct ccw_device *cdev)
102 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
105 urd->reclen = cdev->id.driver_info;
106 ccw_device_get_id(cdev, &urd->dev_id);
107 mutex_init(&urd->io_mutex);
108 init_waitqueue_head(&urd->wait);
109 spin_lock_init(&urd->open_lock);
110 atomic_set(&urd->ref_count, 1);
112 get_device(&cdev->dev);
116 static void urdev_free(struct urdev *urd)
118 TRACE("urdev_free: %p\n", urd);
120 put_device(&urd->cdev->dev);
124 static void urdev_get(struct urdev *urd)
126 atomic_inc(&urd->ref_count);
129 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
134 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
135 urd = dev_get_drvdata(&cdev->dev);
138 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
142 static struct urdev *urdev_get_from_devno(u16 devno)
145 struct ccw_device *cdev;
148 sprintf(bus_id, "0.0.%04x", devno);
149 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
152 urd = urdev_get_from_cdev(cdev);
153 put_device(&cdev->dev);
157 static void urdev_put(struct urdev *urd)
159 if (atomic_dec_and_test(&urd->ref_count))
164 * State and contents of ur devices can be changed by class D users issuing
165 * CP commands such as PURGE or TRANSFER, while the Linux guest is suspended.
166 * Also the Linux guest might be logged off, which causes all active spool
167 * files to be closed.
168 * So we cannot guarantee that spool files are still the same when the Linux
169 * guest is resumed. In order to avoid unpredictable results at resume time
170 * we simply refuse to suspend if a ur device node is open.
172 static int ur_pm_suspend(struct ccw_device *cdev)
174 struct urdev *urd = dev_get_drvdata(&cdev->dev);
176 TRACE("ur_pm_suspend: cdev=%p\n", cdev);
177 if (urd->open_flag) {
178 pr_err("Unit record device %s is busy, %s refusing to "
179 "suspend.\n", dev_name(&cdev->dev), ur_banner);
186 * Low-level functions to do I/O to a ur device.
192 * alloc_chan_prog allocates and builds the channel program
193 * free_chan_prog frees memory of the channel program
195 * do_ur_io issues the channel program to the device and blocks waiting
196 * on a completion event it publishes at urd->io_done. The function
197 * serialises itself on the device's mutex so that only one I/O
198 * is issued at a time (and that I/O is synchronous).
200 * ur_int_handler catches the "I/O done" interrupt, writes the
201 * subchannel status word into the scsw member of the urdev structure
202 * and complete()s the io_done to wake the waiting do_ur_io.
204 * The caller of do_ur_io is responsible for kfree()ing the channel program
205 * address pointer that alloc_chan_prog returned.
208 static void free_chan_prog(struct ccw1 *cpa)
210 struct ccw1 *ptr = cpa;
213 kfree((void *)(addr_t) ptr->cda);
221 * The channel program we use is write commands chained together
222 * with a final NOP CCW command-chained on (which ensures that CE and DE
223 * are presented together in a single interrupt instead of as separate
224 * interrupts unless an incorrect length indication kicks in first). The
225 * data length in each CCW is reclen.
227 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
234 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
237 * We chain a NOP onto the writes to force CE+DE together.
238 * That means we allocate room for CCWs to cover count/reclen
239 * records plus a NOP.
241 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
242 GFP_KERNEL | GFP_DMA);
244 return ERR_PTR(-ENOMEM);
246 for (i = 0; i < rec_count; i++) {
247 cpa[i].cmd_code = WRITE_CCW_CMD;
248 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
249 cpa[i].count = reclen;
250 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
253 return ERR_PTR(-ENOMEM);
255 cpa[i].cda = (u32)(addr_t) kbuf;
256 if (copy_from_user(kbuf, ubuf, reclen)) {
258 return ERR_PTR(-EFAULT);
262 /* The following NOP CCW forces CE+DE to be presented together */
263 cpa[i].cmd_code = CCW_CMD_NOOP;
267 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
270 struct ccw_device *cdev = urd->cdev;
271 DECLARE_COMPLETION_ONSTACK(event);
273 TRACE("do_ur_io: cpa=%p\n", cpa);
275 rc = mutex_lock_interruptible(&urd->io_mutex);
279 urd->io_done = &event;
281 spin_lock_irq(get_ccwdev_lock(cdev));
282 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
283 spin_unlock_irq(get_ccwdev_lock(cdev));
285 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
289 wait_for_completion(&event);
290 TRACE("do_ur_io: I/O complete\n");
294 mutex_unlock(&urd->io_mutex);
299 * ur interrupt handler, called from the ccw_device layer
301 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
306 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
307 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
308 irb->scsw.cmd.count);
311 TRACE("ur_int_handler: unsolicited interrupt\n");
314 urd = dev_get_drvdata(&cdev->dev);
316 /* On special conditions irb is an error pointer */
318 urd->io_request_rc = PTR_ERR(irb);
319 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
320 urd->io_request_rc = 0;
322 urd->io_request_rc = -EIO;
324 complete(urd->io_done);
328 * reclen sysfs attribute - The record length to be used for write CCWs
330 static ssize_t ur_attr_reclen_show(struct device *dev,
331 struct device_attribute *attr, char *buf)
336 urd = urdev_get_from_cdev(to_ccwdev(dev));
339 rc = sprintf(buf, "%zu\n", urd->reclen);
344 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
346 static int ur_create_attributes(struct device *dev)
348 return device_create_file(dev, &dev_attr_reclen);
351 static void ur_remove_attributes(struct device *dev)
353 device_remove_file(dev, &dev_attr_reclen);
357 * diagnose code 0x210 - retrieve device information
358 * cc=0 normal completion, we have a real device
359 * cc=1 CP paging error
360 * cc=2 The virtual device exists, but is not associated with a real device
361 * cc=3 Invalid device address, or the virtual device does not exist
363 static int get_urd_class(struct urdev *urd)
365 static struct diag210 ur_diag210;
368 ur_diag210.vrdcdvno = urd->dev_id.devno;
369 ur_diag210.vrdclen = sizeof(struct diag210);
371 cc = diag210(&ur_diag210);
376 return ur_diag210.vrdcvcla; /* virtual device class */
385 * Allocation and freeing of urfile structures
387 static struct urfile *urfile_alloc(struct urdev *urd)
391 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
396 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
402 static void urfile_free(struct urfile *urf)
404 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
409 * The fops implementation of the character device driver
411 static ssize_t do_write(struct urdev *urd, const char __user *udata,
412 size_t count, size_t reclen, loff_t *ppos)
417 cpa = alloc_chan_prog(udata, count / reclen, reclen);
421 rc = do_ur_io(urd, cpa);
425 if (urd->io_request_rc) {
426 rc = urd->io_request_rc;
437 static ssize_t ur_write(struct file *file, const char __user *udata,
438 size_t count, loff_t *ppos)
440 struct urfile *urf = file->private_data;
442 TRACE("ur_write: count=%zu\n", count);
447 if (count % urf->dev_reclen)
448 return -EINVAL; /* count must be a multiple of reclen */
450 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
451 count = urf->dev_reclen * MAX_RECS_PER_IO;
453 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
457 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
459 * cc=0 normal completion
460 * cc=2 no file active on the virtual reader or device not ready
461 * cc=3 record specified is beyond EOF
463 static int diag_position_to_record(int devno, int record)
467 cc = diag14(record, devno, 0x28);
474 return -ENODATA; /* position beyond end of file */
481 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
482 * cc=0 normal completion
484 * cc=2 no file active on the virtual reader, and no file eligible
485 * cc=3 file already active on the virtual reader or specified virtual
486 * reader does not exist or is not a reader
488 static int diag_read_file(int devno, char *buf)
492 cc = diag14((unsigned long) buf, devno, 0x00);
505 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
508 size_t len, copied, res;
514 urd = ((struct urfile *) file->private_data)->urd;
515 reclen = ((struct urfile *) file->private_data)->file_reclen;
517 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
523 len = min((size_t) PAGE_SIZE, count);
524 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
529 res = (size_t) (*offs % PAGE_SIZE);
531 rc = diag_read_file(urd->dev_id.devno, buf);
532 if (rc == -ENODATA) {
537 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
538 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
539 len = min(count - copied, PAGE_SIZE - res);
540 if (copy_to_user(ubuf + copied, buf + res, len)) {
546 } while (copied != count);
551 free_page((unsigned long) buf);
555 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
561 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
566 urd = ((struct urfile *) file->private_data)->urd;
567 rc = mutex_lock_interruptible(&urd->io_mutex);
570 rc = diag14_read(file, ubuf, count, offs);
571 mutex_unlock(&urd->io_mutex);
576 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
577 * cc=0 normal completion
578 * cc=1 no files on reader queue or no subsequent file
579 * cc=2 spid specified is invalid
581 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
585 cc = diag14((unsigned long) buf, spid, 0xfff);
594 static int verify_uri_device(struct urdev *urd)
596 struct file_control_block *fcb;
600 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
604 /* check for empty reader device (beginning of chain) */
605 rc = diag_read_next_file_info(fcb, 0);
609 /* if file is in hold status, we do not read it */
610 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
615 /* open file on virtual reader */
616 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
621 rc = diag_read_file(urd->dev_id.devno, buf);
622 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
625 /* check if the file on top of the queue is open now */
626 rc = diag_read_next_file_info(fcb, 0);
629 if (!(fcb->file_stat & FLG_IN_USE)) {
636 free_page((unsigned long) buf);
642 static int verify_device(struct urdev *urd)
644 switch (urd->class) {
646 return 0; /* no check needed here */
648 return verify_uri_device(urd);
654 static int get_uri_file_reclen(struct urdev *urd)
656 struct file_control_block *fcb;
659 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
662 rc = diag_read_next_file_info(fcb, 0);
665 if (fcb->file_stat & FLG_CP_DUMP)
675 static int get_file_reclen(struct urdev *urd)
677 switch (urd->class) {
681 return get_uri_file_reclen(urd);
687 static int ur_open(struct inode *inode, struct file *file)
692 unsigned short accmode;
695 accmode = file->f_flags & O_ACCMODE;
697 if (accmode == O_RDWR)
700 * We treat the minor number as the devno of the ur device
701 * to find in the driver tree.
703 devno = MINOR(file->f_dentry->d_inode->i_rdev);
705 urd = urdev_get_from_devno(devno);
711 spin_lock(&urd->open_lock);
712 while (urd->open_flag) {
713 spin_unlock(&urd->open_lock);
714 if (file->f_flags & O_NONBLOCK) {
718 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
722 spin_lock(&urd->open_lock);
725 spin_unlock(&urd->open_lock);
729 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
730 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
731 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
736 rc = verify_device(urd);
740 urf = urfile_alloc(urd);
746 urf->dev_reclen = urd->reclen;
747 rc = get_file_reclen(urd);
749 goto fail_urfile_free;
750 urf->file_reclen = rc;
751 file->private_data = urf;
757 spin_lock(&urd->open_lock);
759 spin_unlock(&urd->open_lock);
766 static int ur_release(struct inode *inode, struct file *file)
768 struct urfile *urf = file->private_data;
770 TRACE("ur_release\n");
771 spin_lock(&urf->urd->open_lock);
772 urf->urd->open_flag--;
773 spin_unlock(&urf->urd->open_lock);
774 wake_up_interruptible(&urf->urd->wait);
780 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
784 if ((file->f_flags & O_ACCMODE) != O_RDONLY)
785 return -ESPIPE; /* seek allowed only for reader */
786 if (offset % PAGE_SIZE)
787 return -ESPIPE; /* only multiples of 4K allowed */
789 case 0: /* SEEK_SET */
792 case 1: /* SEEK_CUR */
793 newpos = file->f_pos + offset;
798 file->f_pos = newpos;
802 static const struct file_operations ur_fops = {
803 .owner = THIS_MODULE,
805 .release = ur_release,
812 * ccw_device infrastructure:
813 * ur_probe creates the struct urdev (with refcount = 1), the device
814 * attributes, sets up the interrupt handler and validates the virtual
815 * unit record device.
816 * ur_remove removes the device attributes and drops the reference to
819 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
820 * by the vmur_mutex lock.
822 * urd->char_device is used as indication that the online function has
823 * been completed successfully.
825 static int ur_probe(struct ccw_device *cdev)
830 TRACE("ur_probe: cdev=%p\n", cdev);
832 mutex_lock(&vmur_mutex);
833 urd = urdev_alloc(cdev);
839 rc = ur_create_attributes(&cdev->dev);
844 cdev->handler = ur_int_handler;
846 /* validate virtual unit record device */
847 urd->class = get_urd_class(urd);
848 if (urd->class < 0) {
850 goto fail_remove_attr;
852 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
854 goto fail_remove_attr;
856 spin_lock_irq(get_ccwdev_lock(cdev));
857 dev_set_drvdata(&cdev->dev, urd);
858 spin_unlock_irq(get_ccwdev_lock(cdev));
860 mutex_unlock(&vmur_mutex);
864 ur_remove_attributes(&cdev->dev);
868 mutex_unlock(&vmur_mutex);
872 static int ur_set_online(struct ccw_device *cdev)
875 int minor, major, rc;
878 TRACE("ur_set_online: cdev=%p\n", cdev);
880 mutex_lock(&vmur_mutex);
881 urd = urdev_get_from_cdev(cdev);
883 /* ur_remove already deleted our urd */
888 if (urd->char_device) {
889 /* Another ur_set_online was faster */
894 minor = urd->dev_id.devno;
895 major = MAJOR(ur_first_dev_maj_min);
897 urd->char_device = cdev_alloc();
898 if (!urd->char_device) {
903 cdev_init(urd->char_device, &ur_fops);
904 urd->char_device->dev = MKDEV(major, minor);
905 urd->char_device->owner = ur_fops.owner;
907 rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
910 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
911 if (urd->class == DEV_CLASS_UR_I)
912 sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
913 if (urd->class == DEV_CLASS_UR_O)
914 sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
915 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
916 sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
922 urd->device = device_create(vmur_class, NULL, urd->char_device->dev,
923 NULL, "%s", node_id);
924 if (IS_ERR(urd->device)) {
925 rc = PTR_ERR(urd->device);
926 TRACE("ur_set_online: device_create rc=%d\n", rc);
930 mutex_unlock(&vmur_mutex);
934 cdev_del(urd->char_device);
935 urd->char_device = NULL;
939 mutex_unlock(&vmur_mutex);
943 static int ur_set_offline_force(struct ccw_device *cdev, int force)
948 TRACE("ur_set_offline: cdev=%p\n", cdev);
949 urd = urdev_get_from_cdev(cdev);
951 /* ur_remove already deleted our urd */
953 if (!urd->char_device) {
954 /* Another ur_set_offline was faster */
958 if (!force && (atomic_read(&urd->ref_count) > 2)) {
959 /* There is still a user of urd (e.g. ur_open) */
960 TRACE("ur_set_offline: BUSY\n");
964 device_destroy(vmur_class, urd->char_device->dev);
965 cdev_del(urd->char_device);
966 urd->char_device = NULL;
974 static int ur_set_offline(struct ccw_device *cdev)
978 mutex_lock(&vmur_mutex);
979 rc = ur_set_offline_force(cdev, 0);
980 mutex_unlock(&vmur_mutex);
984 static void ur_remove(struct ccw_device *cdev)
988 TRACE("ur_remove\n");
990 mutex_lock(&vmur_mutex);
993 ur_set_offline_force(cdev, 1);
994 ur_remove_attributes(&cdev->dev);
996 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
997 urdev_put(dev_get_drvdata(&cdev->dev));
998 dev_set_drvdata(&cdev->dev, NULL);
999 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1001 mutex_unlock(&vmur_mutex);
1005 * Module initialisation and cleanup
1007 static int __init ur_init(void)
1012 if (!MACHINE_IS_VM) {
1013 pr_err("The %s cannot be loaded without z/VM\n",
1018 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
1021 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
1025 debug_set_level(vmur_dbf, 6);
1027 vmur_class = class_create(THIS_MODULE, "vmur");
1028 if (IS_ERR(vmur_class)) {
1029 rc = PTR_ERR(vmur_class);
1033 rc = ccw_driver_register(&ur_driver);
1035 goto fail_class_destroy;
1037 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1039 pr_err("Kernel function alloc_chrdev_region failed with "
1040 "error code %d\n", rc);
1041 goto fail_unregister_driver;
1043 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1045 pr_info("%s loaded.\n", ur_banner);
1048 fail_unregister_driver:
1049 ccw_driver_unregister(&ur_driver);
1051 class_destroy(vmur_class);
1053 debug_unregister(vmur_dbf);
1057 static void __exit ur_exit(void)
1059 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1060 ccw_driver_unregister(&ur_driver);
1061 class_destroy(vmur_class);
1062 debug_unregister(vmur_dbf);
1063 pr_info("%s unloaded.\n", ur_banner);
1066 module_init(ur_init);
1067 module_exit(ur_exit);