![Hendrik Brueckner](/assets/img/avatar_default.png)
When creating the virtual unit record (UR) device, specify the parent CCW device. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1071 lines
24 KiB
C
1071 lines
24 KiB
C
/*
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* Linux driver for System z and s390 unit record devices
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* (z/VM virtual punch, reader, printer)
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*
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* Copyright IBM Corp. 2001, 2009
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* Authors: Malcolm Beattie <beattiem@uk.ibm.com>
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* Michael Holzheu <holzheu@de.ibm.com>
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* Frank Munzert <munzert@de.ibm.com>
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*/
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#define KMSG_COMPONENT "vmur"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <asm/uaccess.h>
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#include <asm/cio.h>
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#include <asm/ccwdev.h>
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#include <asm/debug.h>
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#include <asm/diag.h>
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#include "vmur.h"
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/*
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* Driver overview
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*
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* Unit record device support is implemented as a character device driver.
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* We can fit at least 16 bits into a device minor number and use the
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* simple method of mapping a character device number with minor abcd
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* to the unit record device with devno abcd.
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* I/O to virtual unit record devices is handled as follows:
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* Reads: Diagnose code 0x14 (input spool file manipulation)
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* is used to read spool data page-wise.
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* Writes: The CCW used is WRITE_CCW_CMD (0x01). The device's record length
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* is available by reading sysfs attr reclen. Each write() to the device
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* must specify an integral multiple (maximal 511) of reclen.
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*/
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static char ur_banner[] = "z/VM virtual unit record device driver";
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MODULE_AUTHOR("IBM Corporation");
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MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
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MODULE_LICENSE("GPL");
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static dev_t ur_first_dev_maj_min;
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static struct class *vmur_class;
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static struct debug_info *vmur_dbf;
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/* We put the device's record length (for writes) in the driver_info field */
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static struct ccw_device_id ur_ids[] = {
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{ CCWDEV_CU_DI(READER_PUNCH_DEVTYPE, 80) },
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{ CCWDEV_CU_DI(PRINTER_DEVTYPE, 132) },
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{ /* end of list */ }
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};
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MODULE_DEVICE_TABLE(ccw, ur_ids);
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static int ur_probe(struct ccw_device *cdev);
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static void ur_remove(struct ccw_device *cdev);
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static int ur_set_online(struct ccw_device *cdev);
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static int ur_set_offline(struct ccw_device *cdev);
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static int ur_pm_suspend(struct ccw_device *cdev);
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static struct ccw_driver ur_driver = {
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.driver = {
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.name = "vmur",
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.owner = THIS_MODULE,
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},
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.ids = ur_ids,
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.probe = ur_probe,
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.remove = ur_remove,
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.set_online = ur_set_online,
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.set_offline = ur_set_offline,
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.freeze = ur_pm_suspend,
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.int_class = IRQIO_VMR,
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};
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static DEFINE_MUTEX(vmur_mutex);
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/*
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* Allocation, freeing, getting and putting of urdev structures
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*
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* Each ur device (urd) contains a reference to its corresponding ccw device
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* (cdev) using the urd->cdev pointer. Each ccw device has a reference to the
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* ur device using dev_get_drvdata(&cdev->dev) pointer.
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*
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* urd references:
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* - ur_probe gets a urd reference, ur_remove drops the reference
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* dev_get_drvdata(&cdev->dev)
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* - ur_open gets a urd reference, ur_release drops the reference
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* (urf->urd)
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*
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* cdev references:
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* - urdev_alloc get a cdev reference (urd->cdev)
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* - urdev_free drops the cdev reference (urd->cdev)
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*
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* Setting and clearing of dev_get_drvdata(&cdev->dev) is protected by the ccwdev lock
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*/
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static struct urdev *urdev_alloc(struct ccw_device *cdev)
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{
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struct urdev *urd;
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urd = kzalloc(sizeof(struct urdev), GFP_KERNEL);
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if (!urd)
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return NULL;
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urd->reclen = cdev->id.driver_info;
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ccw_device_get_id(cdev, &urd->dev_id);
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mutex_init(&urd->io_mutex);
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init_waitqueue_head(&urd->wait);
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spin_lock_init(&urd->open_lock);
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atomic_set(&urd->ref_count, 1);
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urd->cdev = cdev;
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get_device(&cdev->dev);
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return urd;
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}
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static void urdev_free(struct urdev *urd)
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{
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TRACE("urdev_free: %p\n", urd);
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if (urd->cdev)
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put_device(&urd->cdev->dev);
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kfree(urd);
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}
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static void urdev_get(struct urdev *urd)
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{
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atomic_inc(&urd->ref_count);
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}
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static struct urdev *urdev_get_from_cdev(struct ccw_device *cdev)
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{
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struct urdev *urd;
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unsigned long flags;
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spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
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urd = dev_get_drvdata(&cdev->dev);
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if (urd)
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urdev_get(urd);
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spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
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return urd;
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}
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static struct urdev *urdev_get_from_devno(u16 devno)
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{
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char bus_id[16];
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struct ccw_device *cdev;
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struct urdev *urd;
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sprintf(bus_id, "0.0.%04x", devno);
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cdev = get_ccwdev_by_busid(&ur_driver, bus_id);
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if (!cdev)
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return NULL;
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urd = urdev_get_from_cdev(cdev);
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put_device(&cdev->dev);
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return urd;
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}
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static void urdev_put(struct urdev *urd)
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{
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if (atomic_dec_and_test(&urd->ref_count))
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urdev_free(urd);
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}
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/*
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* State and contents of ur devices can be changed by class D users issuing
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* CP commands such as PURGE or TRANSFER, while the Linux guest is suspended.
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* Also the Linux guest might be logged off, which causes all active spool
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* files to be closed.
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* So we cannot guarantee that spool files are still the same when the Linux
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* guest is resumed. In order to avoid unpredictable results at resume time
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* we simply refuse to suspend if a ur device node is open.
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*/
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static int ur_pm_suspend(struct ccw_device *cdev)
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{
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struct urdev *urd = dev_get_drvdata(&cdev->dev);
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TRACE("ur_pm_suspend: cdev=%p\n", cdev);
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if (urd->open_flag) {
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pr_err("Unit record device %s is busy, %s refusing to "
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"suspend.\n", dev_name(&cdev->dev), ur_banner);
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return -EBUSY;
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}
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return 0;
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}
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/*
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* Low-level functions to do I/O to a ur device.
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* alloc_chan_prog
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* free_chan_prog
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* do_ur_io
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* ur_int_handler
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*
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* alloc_chan_prog allocates and builds the channel program
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* free_chan_prog frees memory of the channel program
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*
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* do_ur_io issues the channel program to the device and blocks waiting
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* on a completion event it publishes at urd->io_done. The function
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* serialises itself on the device's mutex so that only one I/O
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* is issued at a time (and that I/O is synchronous).
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*
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* ur_int_handler catches the "I/O done" interrupt, writes the
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* subchannel status word into the scsw member of the urdev structure
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* and complete()s the io_done to wake the waiting do_ur_io.
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*
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* The caller of do_ur_io is responsible for kfree()ing the channel program
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* address pointer that alloc_chan_prog returned.
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*/
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static void free_chan_prog(struct ccw1 *cpa)
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{
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struct ccw1 *ptr = cpa;
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while (ptr->cda) {
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kfree((void *)(addr_t) ptr->cda);
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ptr++;
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}
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kfree(cpa);
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}
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/*
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* alloc_chan_prog
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* The channel program we use is write commands chained together
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* with a final NOP CCW command-chained on (which ensures that CE and DE
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* are presented together in a single interrupt instead of as separate
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* interrupts unless an incorrect length indication kicks in first). The
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* data length in each CCW is reclen.
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*/
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static struct ccw1 *alloc_chan_prog(const char __user *ubuf, int rec_count,
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int reclen)
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{
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struct ccw1 *cpa;
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void *kbuf;
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int i;
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TRACE("alloc_chan_prog(%p, %i, %i)\n", ubuf, rec_count, reclen);
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/*
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* We chain a NOP onto the writes to force CE+DE together.
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* That means we allocate room for CCWs to cover count/reclen
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* records plus a NOP.
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*/
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cpa = kzalloc((rec_count + 1) * sizeof(struct ccw1),
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GFP_KERNEL | GFP_DMA);
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if (!cpa)
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return ERR_PTR(-ENOMEM);
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for (i = 0; i < rec_count; i++) {
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cpa[i].cmd_code = WRITE_CCW_CMD;
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cpa[i].flags = CCW_FLAG_CC | CCW_FLAG_SLI;
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cpa[i].count = reclen;
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kbuf = kmalloc(reclen, GFP_KERNEL | GFP_DMA);
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if (!kbuf) {
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free_chan_prog(cpa);
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return ERR_PTR(-ENOMEM);
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}
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cpa[i].cda = (u32)(addr_t) kbuf;
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if (copy_from_user(kbuf, ubuf, reclen)) {
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free_chan_prog(cpa);
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return ERR_PTR(-EFAULT);
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}
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ubuf += reclen;
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}
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/* The following NOP CCW forces CE+DE to be presented together */
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cpa[i].cmd_code = CCW_CMD_NOOP;
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return cpa;
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}
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static int do_ur_io(struct urdev *urd, struct ccw1 *cpa)
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{
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int rc;
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struct ccw_device *cdev = urd->cdev;
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DECLARE_COMPLETION_ONSTACK(event);
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TRACE("do_ur_io: cpa=%p\n", cpa);
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rc = mutex_lock_interruptible(&urd->io_mutex);
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if (rc)
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return rc;
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urd->io_done = &event;
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spin_lock_irq(get_ccwdev_lock(cdev));
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rc = ccw_device_start(cdev, cpa, 1, 0, 0);
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spin_unlock_irq(get_ccwdev_lock(cdev));
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TRACE("do_ur_io: ccw_device_start returned %d\n", rc);
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if (rc)
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goto out;
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wait_for_completion(&event);
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TRACE("do_ur_io: I/O complete\n");
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rc = 0;
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out:
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mutex_unlock(&urd->io_mutex);
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return rc;
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}
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/*
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* ur interrupt handler, called from the ccw_device layer
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*/
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static void ur_int_handler(struct ccw_device *cdev, unsigned long intparm,
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struct irb *irb)
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{
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struct urdev *urd;
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TRACE("ur_int_handler: intparm=0x%lx cstat=%02x dstat=%02x res=%u\n",
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intparm, irb->scsw.cmd.cstat, irb->scsw.cmd.dstat,
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irb->scsw.cmd.count);
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if (!intparm) {
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TRACE("ur_int_handler: unsolicited interrupt\n");
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return;
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}
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urd = dev_get_drvdata(&cdev->dev);
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BUG_ON(!urd);
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/* On special conditions irb is an error pointer */
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if (IS_ERR(irb))
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urd->io_request_rc = PTR_ERR(irb);
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else if (irb->scsw.cmd.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END))
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urd->io_request_rc = 0;
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else
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urd->io_request_rc = -EIO;
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complete(urd->io_done);
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}
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/*
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* reclen sysfs attribute - The record length to be used for write CCWs
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*/
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static ssize_t ur_attr_reclen_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct urdev *urd;
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int rc;
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urd = urdev_get_from_cdev(to_ccwdev(dev));
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if (!urd)
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return -ENODEV;
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rc = sprintf(buf, "%zu\n", urd->reclen);
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urdev_put(urd);
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return rc;
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}
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static DEVICE_ATTR(reclen, 0444, ur_attr_reclen_show, NULL);
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static int ur_create_attributes(struct device *dev)
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{
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return device_create_file(dev, &dev_attr_reclen);
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}
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static void ur_remove_attributes(struct device *dev)
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{
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device_remove_file(dev, &dev_attr_reclen);
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}
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/*
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* diagnose code 0x210 - retrieve device information
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* cc=0 normal completion, we have a real device
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* cc=1 CP paging error
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* cc=2 The virtual device exists, but is not associated with a real device
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* cc=3 Invalid device address, or the virtual device does not exist
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*/
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static int get_urd_class(struct urdev *urd)
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{
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static struct diag210 ur_diag210;
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int cc;
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ur_diag210.vrdcdvno = urd->dev_id.devno;
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ur_diag210.vrdclen = sizeof(struct diag210);
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cc = diag210(&ur_diag210);
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switch (cc) {
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case 0:
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return -EOPNOTSUPP;
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case 2:
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return ur_diag210.vrdcvcla; /* virtual device class */
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case 3:
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return -ENODEV;
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default:
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return -EIO;
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}
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}
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/*
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* Allocation and freeing of urfile structures
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*/
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static struct urfile *urfile_alloc(struct urdev *urd)
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{
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struct urfile *urf;
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urf = kzalloc(sizeof(struct urfile), GFP_KERNEL);
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if (!urf)
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return NULL;
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urf->urd = urd;
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TRACE("urfile_alloc: urd=%p urf=%p rl=%zu\n", urd, urf,
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urf->dev_reclen);
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return urf;
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}
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static void urfile_free(struct urfile *urf)
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{
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TRACE("urfile_free: urf=%p urd=%p\n", urf, urf->urd);
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kfree(urf);
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}
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/*
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* The fops implementation of the character device driver
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*/
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static ssize_t do_write(struct urdev *urd, const char __user *udata,
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size_t count, size_t reclen, loff_t *ppos)
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{
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struct ccw1 *cpa;
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int rc;
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cpa = alloc_chan_prog(udata, count / reclen, reclen);
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if (IS_ERR(cpa))
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return PTR_ERR(cpa);
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rc = do_ur_io(urd, cpa);
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if (rc)
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goto fail_kfree_cpa;
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if (urd->io_request_rc) {
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rc = urd->io_request_rc;
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goto fail_kfree_cpa;
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}
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*ppos += count;
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rc = count;
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fail_kfree_cpa:
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free_chan_prog(cpa);
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return rc;
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}
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static ssize_t ur_write(struct file *file, const char __user *udata,
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size_t count, loff_t *ppos)
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{
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struct urfile *urf = file->private_data;
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TRACE("ur_write: count=%zu\n", count);
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if (count == 0)
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return 0;
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if (count % urf->dev_reclen)
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return -EINVAL; /* count must be a multiple of reclen */
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|
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if (count > urf->dev_reclen * MAX_RECS_PER_IO)
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count = urf->dev_reclen * MAX_RECS_PER_IO;
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return do_write(urf->urd, udata, count, urf->dev_reclen, ppos);
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}
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|
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/*
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* diagnose code 0x14 subcode 0x0028 - position spool file to designated
|
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* record
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* cc=0 normal completion
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* cc=2 no file active on the virtual reader or device not ready
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* cc=3 record specified is beyond EOF
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*/
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static int diag_position_to_record(int devno, int record)
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{
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int cc;
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cc = diag14(record, devno, 0x28);
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switch (cc) {
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case 0:
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return 0;
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case 2:
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return -ENOMEDIUM;
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case 3:
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return -ENODATA; /* position beyond end of file */
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default:
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return -EIO;
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}
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}
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|
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/*
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* diagnose code 0x14 subcode 0x0000 - read next spool file buffer
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* cc=0 normal completion
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* cc=1 EOF reached
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* cc=2 no file active on the virtual reader, and no file eligible
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* cc=3 file already active on the virtual reader or specified virtual
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* reader does not exist or is not a reader
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*/
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static int diag_read_file(int devno, char *buf)
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{
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int cc;
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|
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cc = diag14((unsigned long) buf, devno, 0x00);
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switch (cc) {
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case 0:
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return 0;
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case 1:
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return -ENODATA;
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case 2:
|
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return -ENOMEDIUM;
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default:
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return -EIO;
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}
|
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}
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|
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static ssize_t diag14_read(struct file *file, char __user *ubuf, size_t count,
|
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loff_t *offs)
|
|
{
|
|
size_t len, copied, res;
|
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char *buf;
|
|
int rc;
|
|
u16 reclen;
|
|
struct urdev *urd;
|
|
|
|
urd = ((struct urfile *) file->private_data)->urd;
|
|
reclen = ((struct urfile *) file->private_data)->file_reclen;
|
|
|
|
rc = diag_position_to_record(urd->dev_id.devno, *offs / PAGE_SIZE + 1);
|
|
if (rc == -ENODATA)
|
|
return 0;
|
|
if (rc)
|
|
return rc;
|
|
|
|
len = min((size_t) PAGE_SIZE, count);
|
|
buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
copied = 0;
|
|
res = (size_t) (*offs % PAGE_SIZE);
|
|
do {
|
|
rc = diag_read_file(urd->dev_id.devno, buf);
|
|
if (rc == -ENODATA) {
|
|
break;
|
|
}
|
|
if (rc)
|
|
goto fail;
|
|
if (reclen && (copied == 0) && (*offs < PAGE_SIZE))
|
|
*((u16 *) &buf[FILE_RECLEN_OFFSET]) = reclen;
|
|
len = min(count - copied, PAGE_SIZE - res);
|
|
if (copy_to_user(ubuf + copied, buf + res, len)) {
|
|
rc = -EFAULT;
|
|
goto fail;
|
|
}
|
|
res = 0;
|
|
copied += len;
|
|
} while (copied != count);
|
|
|
|
*offs += copied;
|
|
rc = copied;
|
|
fail:
|
|
free_page((unsigned long) buf);
|
|
return rc;
|
|
}
|
|
|
|
static ssize_t ur_read(struct file *file, char __user *ubuf, size_t count,
|
|
loff_t *offs)
|
|
{
|
|
struct urdev *urd;
|
|
int rc;
|
|
|
|
TRACE("ur_read: count=%zu ppos=%li\n", count, (unsigned long) *offs);
|
|
|
|
if (count == 0)
|
|
return 0;
|
|
|
|
urd = ((struct urfile *) file->private_data)->urd;
|
|
rc = mutex_lock_interruptible(&urd->io_mutex);
|
|
if (rc)
|
|
return rc;
|
|
rc = diag14_read(file, ubuf, count, offs);
|
|
mutex_unlock(&urd->io_mutex);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* diagnose code 0x14 subcode 0x0fff - retrieve next file descriptor
|
|
* cc=0 normal completion
|
|
* cc=1 no files on reader queue or no subsequent file
|
|
* cc=2 spid specified is invalid
|
|
*/
|
|
static int diag_read_next_file_info(struct file_control_block *buf, int spid)
|
|
{
|
|
int cc;
|
|
|
|
cc = diag14((unsigned long) buf, spid, 0xfff);
|
|
switch (cc) {
|
|
case 0:
|
|
return 0;
|
|
default:
|
|
return -ENODATA;
|
|
}
|
|
}
|
|
|
|
static int verify_uri_device(struct urdev *urd)
|
|
{
|
|
struct file_control_block *fcb;
|
|
char *buf;
|
|
int rc;
|
|
|
|
fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
|
|
if (!fcb)
|
|
return -ENOMEM;
|
|
|
|
/* check for empty reader device (beginning of chain) */
|
|
rc = diag_read_next_file_info(fcb, 0);
|
|
if (rc)
|
|
goto fail_free_fcb;
|
|
|
|
/* if file is in hold status, we do not read it */
|
|
if (fcb->file_stat & (FLG_SYSTEM_HOLD | FLG_USER_HOLD)) {
|
|
rc = -EPERM;
|
|
goto fail_free_fcb;
|
|
}
|
|
|
|
/* open file on virtual reader */
|
|
buf = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
|
|
if (!buf) {
|
|
rc = -ENOMEM;
|
|
goto fail_free_fcb;
|
|
}
|
|
rc = diag_read_file(urd->dev_id.devno, buf);
|
|
if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */
|
|
goto fail_free_buf;
|
|
|
|
/* check if the file on top of the queue is open now */
|
|
rc = diag_read_next_file_info(fcb, 0);
|
|
if (rc)
|
|
goto fail_free_buf;
|
|
if (!(fcb->file_stat & FLG_IN_USE)) {
|
|
rc = -EMFILE;
|
|
goto fail_free_buf;
|
|
}
|
|
rc = 0;
|
|
|
|
fail_free_buf:
|
|
free_page((unsigned long) buf);
|
|
fail_free_fcb:
|
|
kfree(fcb);
|
|
return rc;
|
|
}
|
|
|
|
static int verify_device(struct urdev *urd)
|
|
{
|
|
switch (urd->class) {
|
|
case DEV_CLASS_UR_O:
|
|
return 0; /* no check needed here */
|
|
case DEV_CLASS_UR_I:
|
|
return verify_uri_device(urd);
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
|
|
static int get_uri_file_reclen(struct urdev *urd)
|
|
{
|
|
struct file_control_block *fcb;
|
|
int rc;
|
|
|
|
fcb = kmalloc(sizeof(*fcb), GFP_KERNEL | GFP_DMA);
|
|
if (!fcb)
|
|
return -ENOMEM;
|
|
rc = diag_read_next_file_info(fcb, 0);
|
|
if (rc)
|
|
goto fail_free;
|
|
if (fcb->file_stat & FLG_CP_DUMP)
|
|
rc = 0;
|
|
else
|
|
rc = fcb->rec_len;
|
|
|
|
fail_free:
|
|
kfree(fcb);
|
|
return rc;
|
|
}
|
|
|
|
static int get_file_reclen(struct urdev *urd)
|
|
{
|
|
switch (urd->class) {
|
|
case DEV_CLASS_UR_O:
|
|
return 0;
|
|
case DEV_CLASS_UR_I:
|
|
return get_uri_file_reclen(urd);
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
|
|
static int ur_open(struct inode *inode, struct file *file)
|
|
{
|
|
u16 devno;
|
|
struct urdev *urd;
|
|
struct urfile *urf;
|
|
unsigned short accmode;
|
|
int rc;
|
|
|
|
accmode = file->f_flags & O_ACCMODE;
|
|
|
|
if (accmode == O_RDWR)
|
|
return -EACCES;
|
|
/*
|
|
* We treat the minor number as the devno of the ur device
|
|
* to find in the driver tree.
|
|
*/
|
|
devno = MINOR(file_inode(file)->i_rdev);
|
|
|
|
urd = urdev_get_from_devno(devno);
|
|
if (!urd) {
|
|
rc = -ENXIO;
|
|
goto out;
|
|
}
|
|
|
|
spin_lock(&urd->open_lock);
|
|
while (urd->open_flag) {
|
|
spin_unlock(&urd->open_lock);
|
|
if (file->f_flags & O_NONBLOCK) {
|
|
rc = -EBUSY;
|
|
goto fail_put;
|
|
}
|
|
if (wait_event_interruptible(urd->wait, urd->open_flag == 0)) {
|
|
rc = -ERESTARTSYS;
|
|
goto fail_put;
|
|
}
|
|
spin_lock(&urd->open_lock);
|
|
}
|
|
urd->open_flag++;
|
|
spin_unlock(&urd->open_lock);
|
|
|
|
TRACE("ur_open\n");
|
|
|
|
if (((accmode == O_RDONLY) && (urd->class != DEV_CLASS_UR_I)) ||
|
|
((accmode == O_WRONLY) && (urd->class != DEV_CLASS_UR_O))) {
|
|
TRACE("ur_open: unsupported dev class (%d)\n", urd->class);
|
|
rc = -EACCES;
|
|
goto fail_unlock;
|
|
}
|
|
|
|
rc = verify_device(urd);
|
|
if (rc)
|
|
goto fail_unlock;
|
|
|
|
urf = urfile_alloc(urd);
|
|
if (!urf) {
|
|
rc = -ENOMEM;
|
|
goto fail_unlock;
|
|
}
|
|
|
|
urf->dev_reclen = urd->reclen;
|
|
rc = get_file_reclen(urd);
|
|
if (rc < 0)
|
|
goto fail_urfile_free;
|
|
urf->file_reclen = rc;
|
|
file->private_data = urf;
|
|
return 0;
|
|
|
|
fail_urfile_free:
|
|
urfile_free(urf);
|
|
fail_unlock:
|
|
spin_lock(&urd->open_lock);
|
|
urd->open_flag--;
|
|
spin_unlock(&urd->open_lock);
|
|
fail_put:
|
|
urdev_put(urd);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static int ur_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct urfile *urf = file->private_data;
|
|
|
|
TRACE("ur_release\n");
|
|
spin_lock(&urf->urd->open_lock);
|
|
urf->urd->open_flag--;
|
|
spin_unlock(&urf->urd->open_lock);
|
|
wake_up_interruptible(&urf->urd->wait);
|
|
urdev_put(urf->urd);
|
|
urfile_free(urf);
|
|
return 0;
|
|
}
|
|
|
|
static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
loff_t newpos;
|
|
|
|
if ((file->f_flags & O_ACCMODE) != O_RDONLY)
|
|
return -ESPIPE; /* seek allowed only for reader */
|
|
if (offset % PAGE_SIZE)
|
|
return -ESPIPE; /* only multiples of 4K allowed */
|
|
switch (whence) {
|
|
case 0: /* SEEK_SET */
|
|
newpos = offset;
|
|
break;
|
|
case 1: /* SEEK_CUR */
|
|
newpos = file->f_pos + offset;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
file->f_pos = newpos;
|
|
return newpos;
|
|
}
|
|
|
|
static const struct file_operations ur_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = ur_open,
|
|
.release = ur_release,
|
|
.read = ur_read,
|
|
.write = ur_write,
|
|
.llseek = ur_llseek,
|
|
};
|
|
|
|
/*
|
|
* ccw_device infrastructure:
|
|
* ur_probe creates the struct urdev (with refcount = 1), the device
|
|
* attributes, sets up the interrupt handler and validates the virtual
|
|
* unit record device.
|
|
* ur_remove removes the device attributes and drops the reference to
|
|
* struct urdev.
|
|
*
|
|
* ur_probe, ur_remove, ur_set_online and ur_set_offline are serialized
|
|
* by the vmur_mutex lock.
|
|
*
|
|
* urd->char_device is used as indication that the online function has
|
|
* been completed successfully.
|
|
*/
|
|
static int ur_probe(struct ccw_device *cdev)
|
|
{
|
|
struct urdev *urd;
|
|
int rc;
|
|
|
|
TRACE("ur_probe: cdev=%p\n", cdev);
|
|
|
|
mutex_lock(&vmur_mutex);
|
|
urd = urdev_alloc(cdev);
|
|
if (!urd) {
|
|
rc = -ENOMEM;
|
|
goto fail_unlock;
|
|
}
|
|
|
|
rc = ur_create_attributes(&cdev->dev);
|
|
if (rc) {
|
|
rc = -ENOMEM;
|
|
goto fail_urdev_put;
|
|
}
|
|
cdev->handler = ur_int_handler;
|
|
|
|
/* validate virtual unit record device */
|
|
urd->class = get_urd_class(urd);
|
|
if (urd->class < 0) {
|
|
rc = urd->class;
|
|
goto fail_remove_attr;
|
|
}
|
|
if ((urd->class != DEV_CLASS_UR_I) && (urd->class != DEV_CLASS_UR_O)) {
|
|
rc = -EOPNOTSUPP;
|
|
goto fail_remove_attr;
|
|
}
|
|
spin_lock_irq(get_ccwdev_lock(cdev));
|
|
dev_set_drvdata(&cdev->dev, urd);
|
|
spin_unlock_irq(get_ccwdev_lock(cdev));
|
|
|
|
mutex_unlock(&vmur_mutex);
|
|
return 0;
|
|
|
|
fail_remove_attr:
|
|
ur_remove_attributes(&cdev->dev);
|
|
fail_urdev_put:
|
|
urdev_put(urd);
|
|
fail_unlock:
|
|
mutex_unlock(&vmur_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static int ur_set_online(struct ccw_device *cdev)
|
|
{
|
|
struct urdev *urd;
|
|
int minor, major, rc;
|
|
char node_id[16];
|
|
|
|
TRACE("ur_set_online: cdev=%p\n", cdev);
|
|
|
|
mutex_lock(&vmur_mutex);
|
|
urd = urdev_get_from_cdev(cdev);
|
|
if (!urd) {
|
|
/* ur_remove already deleted our urd */
|
|
rc = -ENODEV;
|
|
goto fail_unlock;
|
|
}
|
|
|
|
if (urd->char_device) {
|
|
/* Another ur_set_online was faster */
|
|
rc = -EBUSY;
|
|
goto fail_urdev_put;
|
|
}
|
|
|
|
minor = urd->dev_id.devno;
|
|
major = MAJOR(ur_first_dev_maj_min);
|
|
|
|
urd->char_device = cdev_alloc();
|
|
if (!urd->char_device) {
|
|
rc = -ENOMEM;
|
|
goto fail_urdev_put;
|
|
}
|
|
|
|
urd->char_device->ops = &ur_fops;
|
|
urd->char_device->dev = MKDEV(major, minor);
|
|
urd->char_device->owner = ur_fops.owner;
|
|
|
|
rc = cdev_add(urd->char_device, urd->char_device->dev, 1);
|
|
if (rc)
|
|
goto fail_free_cdev;
|
|
if (urd->cdev->id.cu_type == READER_PUNCH_DEVTYPE) {
|
|
if (urd->class == DEV_CLASS_UR_I)
|
|
sprintf(node_id, "vmrdr-%s", dev_name(&cdev->dev));
|
|
if (urd->class == DEV_CLASS_UR_O)
|
|
sprintf(node_id, "vmpun-%s", dev_name(&cdev->dev));
|
|
} else if (urd->cdev->id.cu_type == PRINTER_DEVTYPE) {
|
|
sprintf(node_id, "vmprt-%s", dev_name(&cdev->dev));
|
|
} else {
|
|
rc = -EOPNOTSUPP;
|
|
goto fail_free_cdev;
|
|
}
|
|
|
|
urd->device = device_create(vmur_class, &cdev->dev,
|
|
urd->char_device->dev, NULL, "%s", node_id);
|
|
if (IS_ERR(urd->device)) {
|
|
rc = PTR_ERR(urd->device);
|
|
TRACE("ur_set_online: device_create rc=%d\n", rc);
|
|
goto fail_free_cdev;
|
|
}
|
|
urdev_put(urd);
|
|
mutex_unlock(&vmur_mutex);
|
|
return 0;
|
|
|
|
fail_free_cdev:
|
|
cdev_del(urd->char_device);
|
|
urd->char_device = NULL;
|
|
fail_urdev_put:
|
|
urdev_put(urd);
|
|
fail_unlock:
|
|
mutex_unlock(&vmur_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static int ur_set_offline_force(struct ccw_device *cdev, int force)
|
|
{
|
|
struct urdev *urd;
|
|
int rc;
|
|
|
|
TRACE("ur_set_offline: cdev=%p\n", cdev);
|
|
urd = urdev_get_from_cdev(cdev);
|
|
if (!urd)
|
|
/* ur_remove already deleted our urd */
|
|
return -ENODEV;
|
|
if (!urd->char_device) {
|
|
/* Another ur_set_offline was faster */
|
|
rc = -EBUSY;
|
|
goto fail_urdev_put;
|
|
}
|
|
if (!force && (atomic_read(&urd->ref_count) > 2)) {
|
|
/* There is still a user of urd (e.g. ur_open) */
|
|
TRACE("ur_set_offline: BUSY\n");
|
|
rc = -EBUSY;
|
|
goto fail_urdev_put;
|
|
}
|
|
device_destroy(vmur_class, urd->char_device->dev);
|
|
cdev_del(urd->char_device);
|
|
urd->char_device = NULL;
|
|
rc = 0;
|
|
|
|
fail_urdev_put:
|
|
urdev_put(urd);
|
|
return rc;
|
|
}
|
|
|
|
static int ur_set_offline(struct ccw_device *cdev)
|
|
{
|
|
int rc;
|
|
|
|
mutex_lock(&vmur_mutex);
|
|
rc = ur_set_offline_force(cdev, 0);
|
|
mutex_unlock(&vmur_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static void ur_remove(struct ccw_device *cdev)
|
|
{
|
|
unsigned long flags;
|
|
|
|
TRACE("ur_remove\n");
|
|
|
|
mutex_lock(&vmur_mutex);
|
|
|
|
if (cdev->online)
|
|
ur_set_offline_force(cdev, 1);
|
|
ur_remove_attributes(&cdev->dev);
|
|
|
|
spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
|
|
urdev_put(dev_get_drvdata(&cdev->dev));
|
|
dev_set_drvdata(&cdev->dev, NULL);
|
|
spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
|
|
|
|
mutex_unlock(&vmur_mutex);
|
|
}
|
|
|
|
/*
|
|
* Module initialisation and cleanup
|
|
*/
|
|
static int __init ur_init(void)
|
|
{
|
|
int rc;
|
|
dev_t dev;
|
|
|
|
if (!MACHINE_IS_VM) {
|
|
pr_err("The %s cannot be loaded without z/VM\n",
|
|
ur_banner);
|
|
return -ENODEV;
|
|
}
|
|
|
|
vmur_dbf = debug_register("vmur", 4, 1, 4 * sizeof(long));
|
|
if (!vmur_dbf)
|
|
return -ENOMEM;
|
|
rc = debug_register_view(vmur_dbf, &debug_sprintf_view);
|
|
if (rc)
|
|
goto fail_free_dbf;
|
|
|
|
debug_set_level(vmur_dbf, 6);
|
|
|
|
vmur_class = class_create(THIS_MODULE, "vmur");
|
|
if (IS_ERR(vmur_class)) {
|
|
rc = PTR_ERR(vmur_class);
|
|
goto fail_free_dbf;
|
|
}
|
|
|
|
rc = ccw_driver_register(&ur_driver);
|
|
if (rc)
|
|
goto fail_class_destroy;
|
|
|
|
rc = alloc_chrdev_region(&dev, 0, NUM_MINORS, "vmur");
|
|
if (rc) {
|
|
pr_err("Kernel function alloc_chrdev_region failed with "
|
|
"error code %d\n", rc);
|
|
goto fail_unregister_driver;
|
|
}
|
|
ur_first_dev_maj_min = MKDEV(MAJOR(dev), 0);
|
|
|
|
pr_info("%s loaded.\n", ur_banner);
|
|
return 0;
|
|
|
|
fail_unregister_driver:
|
|
ccw_driver_unregister(&ur_driver);
|
|
fail_class_destroy:
|
|
class_destroy(vmur_class);
|
|
fail_free_dbf:
|
|
debug_unregister(vmur_dbf);
|
|
return rc;
|
|
}
|
|
|
|
static void __exit ur_exit(void)
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{
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unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
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ccw_driver_unregister(&ur_driver);
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class_destroy(vmur_class);
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debug_unregister(vmur_dbf);
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pr_info("%s unloaded.\n", ur_banner);
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}
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module_init(ur_init);
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module_exit(ur_exit);
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