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,
73 * Allocation, freeing, getting and putting of urdev structures
75 static struct urdev *urdev_alloc(struct ccw_device *cdev)
79 urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
83 urd->reclen = cdev->id.driver_info;
84 ccw_device_get_id(cdev, &urd->dev_id);
85 mutex_init(&urd->io_mutex);
86 mutex_init(&urd->open_mutex);
90 static void urdev_free(struct urdev *urd)
96 * This is how the character device driver gets a reference to a
97 * ur device. When this call returns successfully, a reference has
98 * been taken (by get_device) on the underlying kobject. The recipient
99 * of this urdev pointer must eventually drop it with urdev_put(urd)
100 * which does the corresponding put_device().
102 static struct urdev *urdev_get_from_devno(u16 devno)
105 struct ccw_device *cdev;
107 sprintf(bus_id, "0.0.%04x", devno);
108 cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
112 return cdev->dev.driver_data;
115 static void urdev_put(struct urdev *urd)
117 put_device(&urd->cdev->dev);
121 * Low-level functions to do I/O to a ur device.
127 * alloc_chan_prog allocates and builds the channel program
128 * free_chan_prog frees memory of the channel program
130 * do_ur_io issues the channel program to the device and blocks waiting
131 * on a completion event it publishes at urd->io_done. The function
132 * serialises itself on the device's mutex so that only one I/O
133 * is issued at a time (and that I/O is synchronous).
135 * ur_int_handler catches the "I/O done" interrupt, writes the
136 * subchannel status word into the scsw member of the urdev structure
137 * and complete()s the io_done to wake the waiting do_ur_io.
139 * The caller of do_ur_io is responsible for kfree()ing the channel program
140 * address pointer that alloc_chan_prog returned.
143 static void free_chan_prog(struct ccw1 *cpa)
145 struct ccw1 *ptr = cpa;
148 kfree((void *)(addr_t) ptr->cda);
156 * The channel program we use is write commands chained together
157 * with a final NOP CCW command-chained on (which ensures that CE and DE
158 * are presented together in a single interrupt instead of as separate
159 * interrupts unless an incorrect length indication kicks in first). The
160 * data length in each CCW is reclen.
162 static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
169 TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
172 * We chain a NOP onto the writes to force CE+DE together.
173 * That means we allocate room for CCWs to cover count/reclen
174 * records plus a NOP.
176 cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
177 GFP_KERNEL | GFP_DMA);
179 return ERR_PTR(-ENOMEM);
181 for (i = 0; i < rec_count; i++) {
182 cpa[i].cmd_code = WRITE_CCW_CMD;
183 cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
184 cpa[i].count = reclen;
185 kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
188 return ERR_PTR(-ENOMEM);
190 cpa[i].cda = (u32)(addr_t) kbuf;
191 if (copy_from_user(kbuf, ubuf, reclen)) {
193 return ERR_PTR(-EFAULT);
197 /* The following NOP CCW forces CE+DE to be presented together */
198 cpa[i].cmd_code = CCW_CMD_NOOP;
202 static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
205 struct ccw_device *cdev = urd->cdev;
206 DECLARE_COMPLETION_ONSTACK(event);
208 TRACE("do_ur_io: cpa=%p\n", cpa);
210 rc = mutex_lock_interruptible(&urd->io_mutex);
214 urd->io_done = &event;
216 spin_lock_irq(get_ccwdev_lock(cdev));
217 rc = ccw_device_start(cdev, cpa, 1, 0, 0);
218 spin_unlock_irq(get_ccwdev_lock(cdev));
220 TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
224 wait_for_completion(&event);
225 TRACE("do_ur_io: I/O complete\n");
229 mutex_unlock(&urd->io_mutex);
234 * ur interrupt handler, called from the ccw_device layer
236 static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
241 TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
242 intparm, irb->scsw.cstat, irb->scsw.dstat, irb->scsw.count);
245 TRACE("ur_int_handler: unsolicited interrupt\n");
248 urd = cdev->dev.driver_data;
249 /* On special conditions irb is an error pointer */
251 urd->io_request_rc = PTR_ERR(irb);
252 else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
253 urd->io_request_rc = 0;
255 urd->io_request_rc = -EIO;
257 complete(urd->io_done);
261 * reclen sysfs attribute - The record length to be used for write CCWs
263 static ssize_t ur_attr_reclen_show(struct device *dev,
264 struct device_attribute *attr, char *buf)
266 struct urdev *urd = dev->driver_data;
268 return sprintf(buf, "%zu\n", urd->reclen);
271 static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
273 static int ur_create_attributes(struct device *dev)
275 return device_create_file(dev, &dev_attr_reclen);
278 static void ur_remove_attributes(struct device *dev)
280 device_remove_file(dev, &dev_attr_reclen);
284 * diagnose code 0x210 - retrieve device information
285 * cc=0 normal completion, we have a real device
286 * cc=1 CP paging error
287 * cc=2 The virtual device exists, but is not associated with a real device
288 * cc=3 Invalid device address, or the virtual device does not exist
290 static int get_urd_class(struct urdev *urd)
292 static struct diag210 ur_diag210;
295 ur_diag210.vrdcdvno = urd->dev_id.devno;
296 ur_diag210.vrdclen = sizeof(struct diag210);
298 cc = diag210(&ur_diag210);
303 return ur_diag210.vrdcvcla; /* virtual device class */
312 * Allocation and freeing of urfile structures
314 static struct urfile *urfile_alloc(struct urdev *urd)
318 urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
323 TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
329 static void urfile_free(struct urfile *urf)
331 TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
336 * The fops implementation of the character device driver
338 static ssize_t do_write(struct urdev *urd, const char __user *udata,
339 size_t count, size_t reclen, loff_t *ppos)
344 cpa = alloc_chan_prog(udata, count / reclen, reclen);
348 rc = do_ur_io(urd, cpa);
352 if (urd->io_request_rc) {
353 rc = urd->io_request_rc;
364 static ssize_t ur_write(struct file *file, const char __user *udata,
365 size_t count, loff_t *ppos)
367 struct urfile *urf = file->private_data;
369 TRACE("ur_write: count=%zu\n", count);
374 if (count % urf->dev_reclen)
375 return -EINVAL; /* count must be a multiple of reclen */
377 if (count > urf->dev_reclen * MAX_RECS_PER_IO)
378 count = urf->dev_reclen * MAX_RECS_PER_IO;
380 return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
384 * diagnose code 0x14 subcode 0x0028 - position spool file to designated
386 * cc=0 normal completion
387 * cc=2 no file active on the virtual reader or device not ready
388 * cc=3 record specified is beyond EOF
390 static int diag_position_to_record(int devno, int record)
394 cc = diag14(record, devno, 0x28);
401 return -ENODATA; /* position beyond end of file */
408 * diagnose code 0x14 subcode 0x0000 - read next spool file buffer
409 * cc=0 normal completion
411 * cc=2 no file active on the virtual reader, and no file eligible
412 * cc=3 file already active on the virtual reader or specified virtual
413 * reader does not exist or is not a reader
415 static int diag_read_file(int devno, char *buf)
419 cc = diag14((unsigned long) buf, devno, 0x00);
432 static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
435 size_t len, copied, res;
441 urd = ((struct urfile *) file->private_data)->urd;
442 reclen = ((struct urfile *) file->private_data)->file_reclen;
444 rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
450 len = min((size_t) PAGE_SIZE, count);
451 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
456 res = (size_t) (*offs % PAGE_SIZE);
458 rc = diag_read_file(urd->dev_id.devno, buf);
459 if (rc == -ENODATA) {
464 if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
465 *((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
466 len = min(count - copied, PAGE_SIZE - res);
467 if (copy_to_user(ubuf + copied, buf + res, len)) {
473 } while (copied != count);
478 free_page((unsigned long) buf);
482 static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
488 TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
493 urd = ((struct urfile *) file->private_data)->urd;
494 rc = mutex_lock_interruptible(&urd->io_mutex);
497 rc = diag14_read(file, ubuf, count, offs);
498 mutex_unlock(&urd->io_mutex);
503 * diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
504 * cc=0 normal completion
505 * cc=1 no files on reader queue or no subsequent file
506 * cc=2 spid specified is invalid
508 static int diag_read_next_file_info(struct file_control_block *buf, int spid)
512 cc = diag14((unsigned long) buf, spid, 0xfff);
521 static int verify_uri_device(struct urdev *urd)
523 struct file_control_block *fcb;
527 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
531 /* check for empty reader device (beginning of chain) */
532 rc = diag_read_next_file_info(fcb, 0);
536 /* if file is in hold status, we do not read it */
537 if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
542 /* open file on virtual reader */
543 buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
548 rc = diag_read_file(urd->dev_id.devno, buf);
549 if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
552 /* check if the file on top of the queue is open now */
553 rc = diag_read_next_file_info(fcb, 0);
556 if (!(fcb->file_stat & FLG_IN_USE)) {
563 free_page((unsigned long) buf);
569 static int verify_device(struct urdev *urd)
571 switch (urd->class) {
573 return 0; /* no check needed here */
575 return verify_uri_device(urd);
581 static int get_uri_file_reclen(struct urdev *urd)
583 struct file_control_block *fcb;
586 fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
589 rc = diag_read_next_file_info(fcb, 0);
592 if (fcb->file_stat & FLG_CP_DUMP)
602 static int get_file_reclen(struct urdev *urd)
604 switch (urd->class) {
608 return get_uri_file_reclen(urd);
614 static int ur_open(struct inode *inode, struct file *file)
619 unsigned short accmode;
622 accmode = file->f_flags & O_ACCMODE;
624 if (accmode == O_RDWR)
628 * We treat the minor number as the devno of the ur device
629 * to find in the driver tree.
631 devno = MINOR(file->f_dentry->d_inode->i_rdev);
633 urd = urdev_get_from_devno(devno);
637 if (file->f_flags & O_NONBLOCK) {
638 if (!mutex_trylock(&urd->open_mutex)) {
643 if (mutex_lock_interruptible(&urd->open_mutex)) {
651 if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
652 ((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
653 TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
658 rc = verify_device(urd);
662 urf = urfile_alloc(urd);
668 urf->dev_reclen = urd->reclen;
669 rc = get_file_reclen(urd);
671 goto fail_urfile_free;
672 urf->file_reclen = rc;
673 file->private_data = urf;
679 mutex_unlock(&urd->open_mutex);
685 static int ur_release(struct inode *inode, struct file *file)
687 struct urfile *urf = file->private_data;
689 TRACE("ur_release\n");
690 mutex_unlock(&urf->urd->open_mutex);
696 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
700 if ((file->f_flags & O_ACCMODE) != O_RDONLY)
701 return -ESPIPE; /* seek allowed only for reader */
702 if (offset % PAGE_SIZE)
703 return -ESPIPE; /* only multiples of 4K allowed */
705 case 0: /* SEEK_SET */
708 case 1: /* SEEK_CUR */
709 newpos = file->f_pos + offset;
714 file->f_pos = newpos;
718 static struct file_operations ur_fops = {
719 .owner = THIS_MODULE,
721 .release = ur_release,
728 * ccw_device infrastructure:
729 * ur_probe gets its own ref to the device (i.e. get_device),
730 * creates the struct urdev, the device attributes, sets up
731 * the interrupt handler and validates the virtual unit record device.
732 * ur_remove removes the device attributes, frees the struct urdev
733 * and drops (put_device) the ref to the device we got in ur_probe.
735 static int ur_probe(struct ccw_device *cdev)
740 TRACE("ur_probe: cdev=%p state=%d\n", cdev, *(int *) cdev->private);
742 if (!get_device(&cdev->dev))
745 urd = urdev_alloc(cdev);
750 rc = ur_create_attributes(&cdev->dev);
755 cdev->dev.driver_data = urd;
756 cdev->handler = ur_int_handler;
758 /* validate virtual unit record device */
759 urd->class = get_urd_class(urd);
760 if (urd->class < 0) {
764 if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
773 put_device(&cdev->dev);
777 static void ur_remove(struct ccw_device *cdev)
779 struct urdev *urd = cdev->dev.driver_data;
781 TRACE("ur_remove\n");
783 ur_set_offline(cdev);
784 ur_remove_attributes(&cdev->dev);
786 put_device(&cdev->dev);
789 static int ur_set_online(struct ccw_device *cdev)
792 int minor, major, rc;
795 TRACE("ur_set_online: cdev=%p state=%d\n", cdev,
796 *(int *) cdev->private);
798 if (!try_module_get(ur_driver.owner))
801 urd = (struct urdev *) cdev->dev.driver_data;
802 minor = urd->dev_id.devno;
803 major = MAJOR(ur_first_dev_maj_min);
805 urd->char_device = cdev_alloc();
806 if (!urd->char_device) {
808 goto fail_module_put;
811 cdev_init(urd->char_device, &ur_fops);
812 urd->char_device->dev = MKDEV(major, minor);
813 urd->char_device->owner = ur_fops.owner;
815 rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
818 if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
819 if (urd->class == DEV_CLASS_UR_I)
820 sprintf(node_id, "vmrdr-%s", cdev->dev.bus_id);
821 if (urd->class == DEV_CLASS_UR_O)
822 sprintf(node_id, "vmpun-%s", cdev->dev.bus_id);
823 } else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
824 sprintf(node_id, "vmprt-%s", cdev->dev.bus_id);
830 urd->device = device_create(vmur_class, NULL, urd->char_device->dev,
832 if (IS_ERR(urd->device)) {
833 rc = PTR_ERR(urd->device);
834 TRACE("ur_set_online: device_create rc=%d\n", rc);
841 cdev_del(urd->char_device);
843 module_put(ur_driver.owner);
848 static int ur_set_offline(struct ccw_device *cdev)
852 TRACE("ur_set_offline: cdev=%p cdev->private=%p state=%d\n",
853 cdev, cdev->private, *(int *) cdev->private);
854 urd = (struct urdev *) cdev->dev.driver_data;
855 device_destroy(vmur_class, urd->char_device->dev);
856 cdev_del(urd->char_device);
857 module_put(ur_driver.owner);
863 * Module initialisation and cleanup
865 static int __init ur_init(void)
870 if (!MACHINE_IS_VM) {
871 PRINT_ERR("%s is only available under z/VM.\n", ur_banner);
875 vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
878 rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
882 debug_set_level(vmur_dbf, 6);
884 rc = ccw_driver_register(&ur_driver);
888 rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
890 PRINT_ERR("alloc_chrdev_region failed: err = %d\n", rc);
891 goto fail_unregister_driver;
893 ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
895 vmur_class = class_create(THIS_MODULE, "vmur");
896 if (IS_ERR(vmur_class)) {
897 rc = PTR_ERR(vmur_class);
898 goto fail_unregister_region;
900 PRINT_INFO("%s loaded.\n", ur_banner);
903 fail_unregister_region:
904 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
905 fail_unregister_driver:
906 ccw_driver_unregister(&ur_driver);
908 debug_unregister(vmur_dbf);
912 static void __exit ur_exit(void)
914 class_destroy(vmur_class);
915 unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
916 ccw_driver_unregister(&ur_driver);
917 debug_unregister(vmur_dbf);
918 PRINT_INFO("%s unloaded.\n", ur_banner);
921 module_init(ur_init);
922 module_exit(ur_exit);