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/module.h>
18 #include <linux/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 = {
74 .set_online = ur_set_online,
75 .set_offline = ur_set_offline,
76 .freeze = ur_pm_suspend,
77 .int_class = IRQIO_VMR,
80 static DEFINE_MUTEX(vmur_mutex);
83 * Allocation, freeing, getting and putting of urdev structures
85 * Each ur device (urd) contains a reference to its corresponding ccw device
86 * (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
87 * ur device using dev_get_drvdata(&cdev->dev) pointer.
90 * - ur_probe gets a urd reference, ur_remove drops the reference
91 * dev_get_drvdata(&cdev->dev)
92 * - ur_open gets a urd reference, ur_release drops the reference
96 * - urdev_alloc get a cdev reference (urd->cdev)
97 * - urdev_free drops the cdev reference (urd->cdev)
99 * Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock
101 static struct urdev *urdev_alloc(struct ccw_device *cdev)
105 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
108 urd->reclen = cdev->id.driver_info;
109 ccw_device_get_id(cdev, &urd->dev_id);
110 mutex_init(&urd->io_mutex);
111 init_waitqueue_head(&urd->wait);
112 spin_lock_init(&urd->open_lock);
113 atomic_set(&urd->ref_count, 1);
115 get_device(&cdev->dev);
119 static void urdev_free(struct urdev *urd)
121 TRACE("urdev_free: %p\n", urd);
123 put_device(&urd->cdev->dev);
127 static void urdev_get(struct urdev *urd)
129 atomic_inc(&urd->ref_count);
132 static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
137 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
138 urd = dev_get_drvdata(&cdev->dev);
141 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
145 static struct urdev *urdev_get_from_devno(u16 devno)
148 struct ccw_device *cdev;
151 sprintf(bus_id, "0.0.%04x", devno);
152 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
155 urd = urdev_get_from_cdev(cdev);
156 put_device(&cdev->dev);
160 static void urdev_put(struct urdev *urd)
162 if (atomic_dec_and_test(&urd->ref_count))
167 * State and contents of ur devices can be changed by class D users issuing
168 * CP commands such as PURGE or TRANSFER, while the Linux guest is suspended.
169 * Also the Linux guest might be logged off, which causes all active spool
170 * files to be closed.
171 * So we cannot guarantee that spool files are still the same when the Linux
172 * guest is resumed. In order to avoid unpredictable results at resume time
173 * we simply refuse to suspend if a ur device node is open.
175 static int ur_pm_suspend(struct ccw_device *cdev)
177 struct urdev *urd = dev_get_drvdata(&cdev->dev);
179 TRACE("ur_pm_suspend: cdev=%p\n", cdev);
180 if (urd->open_flag) {
181 pr_err("Unit record device %s is busy, %s refusing to "
182 "suspend.\n", dev_name(&cdev->dev), ur_banner);
189 * Low-level functions to do I/O to a ur device.
195 * alloc_chan_prog allocates and builds the channel program
196 * free_chan_prog frees memory of the channel program
198 * do_ur_io issues the channel program to the device and blocks waiting
199 * on a completion event it publishes at urd->io_done. The function
200 * serialises itself on the device's mutex so that only one I/O
201 * is issued at a time (and that I/O is synchronous).
203 * ur_int_handler catches the "I/O done" interrupt, writes the
204 * subchannel status word into the scsw member of the urdev structure
205 * and complete()s the io_done to wake the waiting do_ur_io.
207 * The caller of do_ur_io is responsible for kfree()ing the channel program
208 * address pointer that alloc_chan_prog returned.
211 static void free_chan_prog(struct ccw1 *cpa)
213 struct ccw1 *ptr = cpa;
216 kfree((void *)(addr_t) ptr->cda);
224 * The channel program we use is write commands chained together
225 * with a final NOP CCW command-chained on (which ensures that CE and DE
226 * are presented together in a single interrupt instead of as separate
227 * interrupts unless an incorrect length indication kicks in first). The
228 * data length in each CCW is reclen.
230 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
237 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
240 * We chain a NOP onto the writes to force CE+DE together.
241 * That means we allocate room for CCWs to cover count/reclen
242 * records plus a NOP.
244 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
245 GFP_KERNEL | GFP_DMA);
247 return ERR_PTR(-ENOMEM);
249 for (i = 0; i < rec_count; i++) {
250 cpa[i].cmd_code = WRITE_CCW_CMD;
251 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
252 cpa[i].count = reclen;
253 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
256 return ERR_PTR(-ENOMEM);
258 cpa[i].cda = (u32)(addr_t) kbuf;
259 if (copy_from_user(kbuf, ubuf, reclen)) {
261 return ERR_PTR(-EFAULT);
265 /* The following NOP CCW forces CE+DE to be presented together */
266 cpa[i].cmd_code = CCW_CMD_NOOP;
270 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
273 struct ccw_device *cdev = urd->cdev;
274 DECLARE_COMPLETION_ONSTACK(event);
276 TRACE("do_ur_io: cpa=%p\n", cpa);
278 rc = mutex_lock_interruptible(&urd->io_mutex);
282 urd->io_done = &event;
284 spin_lock_irq(get_ccwdev_lock(cdev));
285 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
286 spin_unlock_irq(get_ccwdev_lock(cdev));
288 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
292 wait_for_completion(&event);
293 TRACE("do_ur_io: I/O complete\n");
297 mutex_unlock(&urd->io_mutex);
302 * ur interrupt handler, called from the ccw_device layer
304 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
310 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
311 intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
312 irb->scsw.cmd.count);
315 TRACE("ur_int_handler: unsolicited interrupt\n");
318 urd = dev_get_drvdata(&cdev->dev);
320 /* On special conditions irb is an error pointer */
322 urd->io_request_rc = PTR_ERR(irb);
323 else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
324 urd->io_request_rc = 0;
326 urd->io_request_rc = -EIO;
328 complete(urd->io_done);
332 * reclen sysfs attribute - The record length to be used for write CCWs
334 static ssize_t ur_attr_reclen_show(struct device *dev,
335 struct device_attribute *attr, char *buf)
340 urd = urdev_get_from_cdev(to_ccwdev(dev));
343 rc = sprintf(buf, "%zu\n", urd->reclen);
348 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
350 static int ur_create_attributes(struct device *dev)
352 return device_create_file(dev, &dev_attr_reclen);
355 static void ur_remove_attributes(struct device *dev)
357 device_remove_file(dev, &dev_attr_reclen);
361 * diagnose code 0x210 - retrieve device information
362 * cc=0 normal completion, we have a real device
363 * cc=1 CP paging error
364 * cc=2 The virtual device exists, but is not associated with a real device
365 * cc=3 Invalid device address, or the virtual device does not exist
367 static int get_urd_class(struct urdev *urd)
369 static struct diag210 ur_diag210;
372 ur_diag210.vrdcdvno = urd->dev_id.devno;
373 ur_diag210.vrdclen = sizeof(struct diag210);
375 cc = diag210(&ur_diag210);
380 return ur_diag210.vrdcvcla; /* virtual device class */
389 * Allocation and freeing of urfile structures
391 static struct urfile *urfile_alloc(struct urdev *urd)
395 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
400 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
406 static void urfile_free(struct urfile *urf)
408 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
413 * The fops implementation of the character device driver
415 static ssize_t do_write(struct urdev *urd, const char __user *udata,
416 size_t count, size_t reclen, loff_t *ppos)
421 cpa = alloc_chan_prog(udata, count / reclen, reclen);
425 rc = do_ur_io(urd, cpa);
429 if (urd->io_request_rc) {
430 rc = urd->io_request_rc;
441 static ssize_t ur_write(struct file *file, const char __user *udata,
442 size_t count, loff_t *ppos)
444 struct urfile *urf = file->private_data;
446 TRACE("ur_write: count=%zu\n", count);
451 if (count % urf->dev_reclen)
452 return -EINVAL; /* count must be a multiple of reclen */
454 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
455 count = urf->dev_reclen * MAX_RECS_PER_IO;
457 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
461 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
463 * cc=0 normal completion
464 * cc=2 no file active on the virtual reader or device not ready
465 * cc=3 record specified is beyond EOF
467 static int diag_position_to_record(int devno, int record)
471 cc = diag14(record, devno, 0x28);
478 return -ENODATA; /* position beyond end of file */
485 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
486 * cc=0 normal completion
488 * cc=2 no file active on the virtual reader, and no file eligible
489 * cc=3 file already active on the virtual reader or specified virtual
490 * reader does not exist or is not a reader
492 static int diag_read_file(int devno, char *buf)
496 cc = diag14((unsigned long) buf, devno, 0x00);
509 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
512 size_t len, copied, res;
518 urd = ((struct urfile *) file->private_data)->urd;
519 reclen = ((struct urfile *) file->private_data)->file_reclen;
521 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
527 len = min((size_t) PAGE_SIZE, count);
528 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
533 res = (size_t) (*offs % PAGE_SIZE);
535 rc = diag_read_file(urd->dev_id.devno, buf);
536 if (rc == -ENODATA) {
541 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
542 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
543 len = min(count - copied, PAGE_SIZE - res);
544 if (copy_to_user(ubuf + copied, buf + res, len)) {
550 } while (copied != count);
555 free_page((unsigned long) buf);
559 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
565 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
570 urd = ((struct urfile *) file->private_data)->urd;
571 rc = mutex_lock_interruptible(&urd->io_mutex);
574 rc = diag14_read(file, ubuf, count, offs);
575 mutex_unlock(&urd->io_mutex);
580 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
581 * cc=0 normal completion
582 * cc=1 no files on reader queue or no subsequent file
583 * cc=2 spid specified is invalid
585 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
589 cc = diag14((unsigned long) buf, spid, 0xfff);
598 static int verify_uri_device(struct urdev *urd)
600 struct file_control_block *fcb;
604 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
608 /* check for empty reader device (beginning of chain) */
609 rc = diag_read_next_file_info(fcb, 0);
613 /* if file is in hold status, we do not read it */
614 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
619 /* open file on virtual reader */
620 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
625 rc = diag_read_file(urd->dev_id.devno, buf);
626 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
629 /* check if the file on top of the queue is open now */
630 rc = diag_read_next_file_info(fcb, 0);
633 if (!(fcb->file_stat & FLG_IN_USE)) {
640 free_page((unsigned long) buf);
646 static int verify_device(struct urdev *urd)
648 switch (urd->class) {
650 return 0; /* no check needed here */
652 return verify_uri_device(urd);
658 static int get_uri_file_reclen(struct urdev *urd)
660 struct file_control_block *fcb;
663 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
666 rc = diag_read_next_file_info(fcb, 0);
669 if (fcb->file_stat & FLG_CP_DUMP)
679 static int get_file_reclen(struct urdev *urd)
681 switch (urd->class) {
685 return get_uri_file_reclen(urd);
691 static int ur_open(struct inode *inode, struct file *file)
696 unsigned short accmode;
699 accmode = file->f_flags & O_ACCMODE;
701 if (accmode == O_RDWR)
704 * We treat the minor number as the devno of the ur device
705 * to find in the driver tree.
707 devno = MINOR(file_inode(file)->i_rdev);
709 urd = urdev_get_from_devno(devno);
715 spin_lock(&urd->open_lock);
716 while (urd->open_flag) {
717 spin_unlock(&urd->open_lock);
718 if (file->f_flags & O_NONBLOCK) {
722 if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
726 spin_lock(&urd->open_lock);
729 spin_unlock(&urd->open_lock);
733 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
734 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
735 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
740 rc = verify_device(urd);
744 urf = urfile_alloc(urd);
750 urf->dev_reclen = urd->reclen;
751 rc = get_file_reclen(urd);
753 goto fail_urfile_free;
754 urf->file_reclen = rc;
755 file->private_data = urf;
761 spin_lock(&urd->open_lock);
763 spin_unlock(&urd->open_lock);
770 static int ur_release(struct inode *inode, struct file *file)
772 struct urfile *urf = file->private_data;
774 TRACE("ur_release\n");
775 spin_lock(&urf->urd->open_lock);
776 urf->urd->open_flag--;
777 spin_unlock(&urf->urd->open_lock);
778 wake_up_interruptible(&urf->urd->wait);
784 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 */
790 return no_seek_end_llseek(file, offset, whence);
793 static const struct file_operations ur_fops = {
794 .owner = THIS_MODULE,
796 .release = ur_release,
803 * ccw_device infrastructure:
804 * ur_probe creates the struct urdev (with refcount = 1), the device
805 * attributes, sets up the interrupt handler and validates the virtual
806 * unit record device.
807 * ur_remove removes the device attributes and drops the reference to
810 * ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
811 * by the vmur_mutex lock.
813 * urd->char_device is used as indication that the online function has
814 * been completed successfully.
816 static int ur_probe(struct ccw_device *cdev)
821 TRACE("ur_probe: cdev=%p\n", cdev);
823 mutex_lock(&vmur_mutex);
824 urd = urdev_alloc(cdev);
830 rc = ur_create_attributes(&cdev->dev);
835 cdev->handler = ur_int_handler;
837 /* validate virtual unit record device */
838 urd->class = get_urd_class(urd);
839 if (urd->class < 0) {
841 goto fail_remove_attr;
843 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
845 goto fail_remove_attr;
847 spin_lock_irq(get_ccwdev_lock(cdev));
848 dev_set_drvdata(&cdev->dev, urd);
849 spin_unlock_irq(get_ccwdev_lock(cdev));
851 mutex_unlock(&vmur_mutex);
855 ur_remove_attributes(&cdev->dev);
859 mutex_unlock(&vmur_mutex);
863 static int ur_set_online(struct ccw_device *cdev)
866 int minor, major, rc;
869 TRACE("ur_set_online: cdev=%p\n", cdev);
871 mutex_lock(&vmur_mutex);
872 urd = urdev_get_from_cdev(cdev);
874 /* ur_remove already deleted our urd */
879 if (urd->char_device) {
880 /* Another ur_set_online was faster */
885 minor = urd->dev_id.devno;
886 major = MAJOR(ur_first_dev_maj_min);
888 urd->char_device = cdev_alloc();
889 if (!urd->char_device) {
894 urd->char_device->ops = &ur_fops;
895 urd->char_device->owner = ur_fops.owner;
897 rc = cdev_add(urd->char_device, MKDEV(major, minor), 1);
900 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
901 if (urd->class == DEV_CLASS_UR_I)
902 sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
903 if (urd->class == DEV_CLASS_UR_O)
904 sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
905 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
906 sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
912 urd->device = device_create(vmur_class, &cdev->dev,
913 urd->char_device->dev, NULL, "%s", node_id);
914 if (IS_ERR(urd->device)) {
915 rc = PTR_ERR(urd->device);
916 TRACE("ur_set_online: device_create rc=%d\n", rc);
920 mutex_unlock(&vmur_mutex);
924 cdev_del(urd->char_device);
925 urd->char_device = NULL;
929 mutex_unlock(&vmur_mutex);
933 static int ur_set_offline_force(struct ccw_device *cdev, int force)
938 TRACE("ur_set_offline: cdev=%p\n", cdev);
939 urd = urdev_get_from_cdev(cdev);
941 /* ur_remove already deleted our urd */
943 if (!urd->char_device) {
944 /* Another ur_set_offline was faster */
948 if (!force && (atomic_read(&urd->ref_count) > 2)) {
949 /* There is still a user of urd (e.g. ur_open) */
950 TRACE("ur_set_offline: BUSY\n");
954 device_destroy(vmur_class, urd->char_device->dev);
955 cdev_del(urd->char_device);
956 urd->char_device = NULL;
964 static int ur_set_offline(struct ccw_device *cdev)
968 mutex_lock(&vmur_mutex);
969 rc = ur_set_offline_force(cdev, 0);
970 mutex_unlock(&vmur_mutex);
974 static void ur_remove(struct ccw_device *cdev)
978 TRACE("ur_remove\n");
980 mutex_lock(&vmur_mutex);
983 ur_set_offline_force(cdev, 1);
984 ur_remove_attributes(&cdev->dev);
986 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
987 urdev_put(dev_get_drvdata(&cdev->dev));
988 dev_set_drvdata(&cdev->dev, NULL);
989 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
991 mutex_unlock(&vmur_mutex);
995 * Module initialisation and cleanup
997 static int __init ur_init(void)
1002 if (!MACHINE_IS_VM) {
1003 pr_err("The %s cannot be loaded without z/VM\n",
1008 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
1011 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
1015 debug_set_level(vmur_dbf, 6);
1017 vmur_class = class_create(THIS_MODULE, "vmur");
1018 if (IS_ERR(vmur_class)) {
1019 rc = PTR_ERR(vmur_class);
1023 rc = ccw_driver_register(&ur_driver);
1025 goto fail_class_destroy;
1027 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
1029 pr_err("Kernel function alloc_chrdev_region failed with "
1030 "error code %d\n", rc);
1031 goto fail_unregister_driver;
1033 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
1035 pr_info("%s loaded.\n", ur_banner);
1038 fail_unregister_driver:
1039 ccw_driver_unregister(&ur_driver);
1041 class_destroy(vmur_class);
1043 debug_unregister(vmur_dbf);
1047 static void __exit ur_exit(void)
1049 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
1050 ccw_driver_unregister(&ur_driver);
1051 class_destroy(vmur_class);
1052 debug_unregister(vmur_dbf);
1053 pr_info("%s unloaded.\n", ur_banner);
1056 module_init(ur_init);
1057 module_exit(ur_exit);