linux/drivers/s390/char/tape_core.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

1380 lines
34 KiB
C

/*
* basic function of the tape device driver
*
* S390 and zSeries version
* Copyright IBM Corp. 2001, 2009
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Michael Holzheu <holzheu@de.ibm.com>
* Tuan Ngo-Anh <ngoanh@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Stefan Bader <shbader@de.ibm.com>
*/
#define KMSG_COMPONENT "tape"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/init.h> // for kernel parameters
#include <linux/kmod.h> // for requesting modules
#include <linux/spinlock.h> // for locks
#include <linux/vmalloc.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <asm/types.h> // for variable types
#define TAPE_DBF_AREA tape_core_dbf
#include "tape.h"
#include "tape_std.h"
#define LONG_BUSY_TIMEOUT 180 /* seconds */
static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
static void tape_delayed_next_request(struct work_struct *);
static void tape_long_busy_timeout(unsigned long data);
/*
* One list to contain all tape devices of all disciplines, so
* we can assign the devices to minor numbers of the same major
* The list is protected by the rwlock
*/
static LIST_HEAD(tape_device_list);
static DEFINE_RWLOCK(tape_device_lock);
/*
* Pointer to debug area.
*/
debug_info_t *TAPE_DBF_AREA = NULL;
EXPORT_SYMBOL(TAPE_DBF_AREA);
/*
* Printable strings for tape enumerations.
*/
const char *tape_state_verbose[TS_SIZE] =
{
[TS_UNUSED] = "UNUSED",
[TS_IN_USE] = "IN_USE",
[TS_BLKUSE] = "BLKUSE",
[TS_INIT] = "INIT ",
[TS_NOT_OPER] = "NOT_OP"
};
const char *tape_op_verbose[TO_SIZE] =
{
[TO_BLOCK] = "BLK", [TO_BSB] = "BSB",
[TO_BSF] = "BSF", [TO_DSE] = "DSE",
[TO_FSB] = "FSB", [TO_FSF] = "FSF",
[TO_LBL] = "LBL", [TO_NOP] = "NOP",
[TO_RBA] = "RBA", [TO_RBI] = "RBI",
[TO_RFO] = "RFO", [TO_REW] = "REW",
[TO_RUN] = "RUN", [TO_WRI] = "WRI",
[TO_WTM] = "WTM", [TO_MSEN] = "MSN",
[TO_LOAD] = "LOA", [TO_READ_CONFIG] = "RCF",
[TO_READ_ATTMSG] = "RAT",
[TO_DIS] = "DIS", [TO_ASSIGN] = "ASS",
[TO_UNASSIGN] = "UAS", [TO_CRYPT_ON] = "CON",
[TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
[TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
};
static int devid_to_int(struct ccw_dev_id *dev_id)
{
return dev_id->devno + (dev_id->ssid << 16);
}
/*
* Some channel attached tape specific attributes.
*
* FIXME: In the future the first_minor and blocksize attribute should be
* replaced by a link to the cdev tree.
*/
static ssize_t
tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct tape_device *tdev;
tdev = dev_get_drvdata(dev);
return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
}
static
DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
static ssize_t
tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct tape_device *tdev;
tdev = dev_get_drvdata(dev);
return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
}
static
DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
static ssize_t
tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct tape_device *tdev;
tdev = dev_get_drvdata(dev);
return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
"OFFLINE" : tape_state_verbose[tdev->tape_state]);
}
static
DEVICE_ATTR(state, 0444, tape_state_show, NULL);
static ssize_t
tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct tape_device *tdev;
ssize_t rc;
tdev = dev_get_drvdata(dev);
if (tdev->first_minor < 0)
return scnprintf(buf, PAGE_SIZE, "N/A\n");
spin_lock_irq(get_ccwdev_lock(tdev->cdev));
if (list_empty(&tdev->req_queue))
rc = scnprintf(buf, PAGE_SIZE, "---\n");
else {
struct tape_request *req;
req = list_entry(tdev->req_queue.next, struct tape_request,
list);
rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
}
spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
return rc;
}
static
DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
static ssize_t
tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct tape_device *tdev;
tdev = dev_get_drvdata(dev);
return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
}
static
DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
static struct attribute *tape_attrs[] = {
&dev_attr_medium_state.attr,
&dev_attr_first_minor.attr,
&dev_attr_state.attr,
&dev_attr_operation.attr,
&dev_attr_blocksize.attr,
NULL
};
static struct attribute_group tape_attr_group = {
.attrs = tape_attrs,
};
/*
* Tape state functions
*/
void
tape_state_set(struct tape_device *device, enum tape_state newstate)
{
const char *str;
if (device->tape_state == TS_NOT_OPER) {
DBF_EVENT(3, "ts_set err: not oper\n");
return;
}
DBF_EVENT(4, "ts. dev: %x\n", device->first_minor);
DBF_EVENT(4, "old ts:\t\n");
if (device->tape_state < TS_SIZE && device->tape_state >=0 )
str = tape_state_verbose[device->tape_state];
else
str = "UNKNOWN TS";
DBF_EVENT(4, "%s\n", str);
DBF_EVENT(4, "new ts:\t\n");
if (newstate < TS_SIZE && newstate >= 0)
str = tape_state_verbose[newstate];
else
str = "UNKNOWN TS";
DBF_EVENT(4, "%s\n", str);
device->tape_state = newstate;
wake_up(&device->state_change_wq);
}
struct tape_med_state_work_data {
struct tape_device *device;
enum tape_medium_state state;
struct work_struct work;
};
static void
tape_med_state_work_handler(struct work_struct *work)
{
static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
struct tape_med_state_work_data *p =
container_of(work, struct tape_med_state_work_data, work);
struct tape_device *device = p->device;
char *envp[] = { NULL, NULL };
switch (p->state) {
case MS_UNLOADED:
pr_info("%s: The tape cartridge has been successfully "
"unloaded\n", dev_name(&device->cdev->dev));
envp[0] = env_state_unloaded;
kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
break;
case MS_LOADED:
pr_info("%s: A tape cartridge has been mounted\n",
dev_name(&device->cdev->dev));
envp[0] = env_state_loaded;
kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
break;
default:
break;
}
tape_put_device(device);
kfree(p);
}
static void
tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
{
struct tape_med_state_work_data *p;
p = kzalloc(sizeof(*p), GFP_ATOMIC);
if (p) {
INIT_WORK(&p->work, tape_med_state_work_handler);
p->device = tape_get_device(device);
p->state = state;
schedule_work(&p->work);
}
}
void
tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
{
enum tape_medium_state oldstate;
oldstate = device->medium_state;
if (oldstate == newstate)
return;
device->medium_state = newstate;
switch(newstate){
case MS_UNLOADED:
device->tape_generic_status |= GMT_DR_OPEN(~0);
if (oldstate == MS_LOADED)
tape_med_state_work(device, MS_UNLOADED);
break;
case MS_LOADED:
device->tape_generic_status &= ~GMT_DR_OPEN(~0);
if (oldstate == MS_UNLOADED)
tape_med_state_work(device, MS_LOADED);
break;
default:
break;
}
wake_up(&device->state_change_wq);
}
/*
* Stop running ccw. Has to be called with the device lock held.
*/
static int
__tape_cancel_io(struct tape_device *device, struct tape_request *request)
{
int retries;
int rc;
/* Check if interrupt has already been processed */
if (request->callback == NULL)
return 0;
rc = 0;
for (retries = 0; retries < 5; retries++) {
rc = ccw_device_clear(device->cdev, (long) request);
switch (rc) {
case 0:
request->status = TAPE_REQUEST_DONE;
return 0;
case -EBUSY:
request->status = TAPE_REQUEST_CANCEL;
schedule_delayed_work(&device->tape_dnr, 0);
return 0;
case -ENODEV:
DBF_EXCEPTION(2, "device gone, retry\n");
break;
case -EIO:
DBF_EXCEPTION(2, "I/O error, retry\n");
break;
default:
BUG();
}
}
return rc;
}
/*
* Add device into the sorted list, giving it the first
* available minor number.
*/
static int
tape_assign_minor(struct tape_device *device)
{
struct tape_device *tmp;
int minor;
minor = 0;
write_lock(&tape_device_lock);
list_for_each_entry(tmp, &tape_device_list, node) {
if (minor < tmp->first_minor)
break;
minor += TAPE_MINORS_PER_DEV;
}
if (minor >= 256) {
write_unlock(&tape_device_lock);
return -ENODEV;
}
device->first_minor = minor;
list_add_tail(&device->node, &tmp->node);
write_unlock(&tape_device_lock);
return 0;
}
/* remove device from the list */
static void
tape_remove_minor(struct tape_device *device)
{
write_lock(&tape_device_lock);
list_del_init(&device->node);
device->first_minor = -1;
write_unlock(&tape_device_lock);
}
/*
* Set a device online.
*
* This function is called by the common I/O layer to move a device from the
* detected but offline into the online state.
* If we return an error (RC < 0) the device remains in the offline state. This
* can happen if the device is assigned somewhere else, for example.
*/
int
tape_generic_online(struct tape_device *device,
struct tape_discipline *discipline)
{
int rc;
DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
if (device->tape_state != TS_INIT) {
DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
return -EINVAL;
}
init_timer(&device->lb_timeout);
device->lb_timeout.function = tape_long_busy_timeout;
/* Let the discipline have a go at the device. */
device->discipline = discipline;
if (!try_module_get(discipline->owner)) {
return -EINVAL;
}
rc = discipline->setup_device(device);
if (rc)
goto out;
rc = tape_assign_minor(device);
if (rc)
goto out_discipline;
rc = tapechar_setup_device(device);
if (rc)
goto out_minor;
tape_state_set(device, TS_UNUSED);
DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
return 0;
out_minor:
tape_remove_minor(device);
out_discipline:
device->discipline->cleanup_device(device);
device->discipline = NULL;
out:
module_put(discipline->owner);
return rc;
}
static void
tape_cleanup_device(struct tape_device *device)
{
tapechar_cleanup_device(device);
device->discipline->cleanup_device(device);
module_put(device->discipline->owner);
tape_remove_minor(device);
tape_med_state_set(device, MS_UNKNOWN);
}
/*
* Suspend device.
*
* Called by the common I/O layer if the drive should be suspended on user
* request. We refuse to suspend if the device is loaded or in use for the
* following reason:
* While the Linux guest is suspended, it might be logged off which causes
* devices to be detached. Tape devices are automatically rewound and unloaded
* during DETACH processing (unless the tape device was attached with the
* NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
* resume the original state of the tape device, since we would need to
* manually re-load the cartridge which was active at suspend time.
*/
int tape_generic_pm_suspend(struct ccw_device *cdev)
{
struct tape_device *device;
device = dev_get_drvdata(&cdev->dev);
if (!device) {
return -ENODEV;
}
DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
device->cdev_id, device);
if (device->medium_state != MS_UNLOADED) {
pr_err("A cartridge is loaded in tape device %s, "
"refusing to suspend\n", dev_name(&cdev->dev));
return -EBUSY;
}
spin_lock_irq(get_ccwdev_lock(device->cdev));
switch (device->tape_state) {
case TS_INIT:
case TS_NOT_OPER:
case TS_UNUSED:
spin_unlock_irq(get_ccwdev_lock(device->cdev));
break;
default:
pr_err("Tape device %s is busy, refusing to "
"suspend\n", dev_name(&cdev->dev));
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return -EBUSY;
}
DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
return 0;
}
/*
* Set device offline.
*
* Called by the common I/O layer if the drive should set offline on user
* request. We may prevent this by returning an error.
* Manual offline is only allowed while the drive is not in use.
*/
int
tape_generic_offline(struct ccw_device *cdev)
{
struct tape_device *device;
device = dev_get_drvdata(&cdev->dev);
if (!device) {
return -ENODEV;
}
DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
device->cdev_id, device);
spin_lock_irq(get_ccwdev_lock(device->cdev));
switch (device->tape_state) {
case TS_INIT:
case TS_NOT_OPER:
spin_unlock_irq(get_ccwdev_lock(device->cdev));
break;
case TS_UNUSED:
tape_state_set(device, TS_INIT);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
tape_cleanup_device(device);
break;
default:
DBF_EVENT(3, "(%08x): Set offline failed "
"- drive in use.\n",
device->cdev_id);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return -EBUSY;
}
DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
return 0;
}
/*
* Allocate memory for a new device structure.
*/
static struct tape_device *
tape_alloc_device(void)
{
struct tape_device *device;
device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
if (device == NULL) {
DBF_EXCEPTION(2, "ti:no mem\n");
return ERR_PTR(-ENOMEM);
}
device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
if (device->modeset_byte == NULL) {
DBF_EXCEPTION(2, "ti:no mem\n");
kfree(device);
return ERR_PTR(-ENOMEM);
}
mutex_init(&device->mutex);
INIT_LIST_HEAD(&device->req_queue);
INIT_LIST_HEAD(&device->node);
init_waitqueue_head(&device->state_change_wq);
init_waitqueue_head(&device->wait_queue);
device->tape_state = TS_INIT;
device->medium_state = MS_UNKNOWN;
*device->modeset_byte = 0;
device->first_minor = -1;
atomic_set(&device->ref_count, 1);
INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
return device;
}
/*
* Get a reference to an existing device structure. This will automatically
* increment the reference count.
*/
struct tape_device *
tape_get_device(struct tape_device *device)
{
int count;
count = atomic_inc_return(&device->ref_count);
DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
return device;
}
/*
* Decrease the reference counter of a devices structure. If the
* reference counter reaches zero free the device structure.
* The function returns a NULL pointer to be used by the caller
* for clearing reference pointers.
*/
void
tape_put_device(struct tape_device *device)
{
int count;
count = atomic_dec_return(&device->ref_count);
DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
BUG_ON(count < 0);
if (count == 0) {
kfree(device->modeset_byte);
kfree(device);
}
}
/*
* Find tape device by a device index.
*/
struct tape_device *
tape_find_device(int devindex)
{
struct tape_device *device, *tmp;
device = ERR_PTR(-ENODEV);
read_lock(&tape_device_lock);
list_for_each_entry(tmp, &tape_device_list, node) {
if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
device = tape_get_device(tmp);
break;
}
}
read_unlock(&tape_device_lock);
return device;
}
/*
* Driverfs tape probe function.
*/
int
tape_generic_probe(struct ccw_device *cdev)
{
struct tape_device *device;
int ret;
struct ccw_dev_id dev_id;
device = tape_alloc_device();
if (IS_ERR(device))
return -ENODEV;
ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
CCWDEV_DO_MULTIPATH);
ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
if (ret) {
tape_put_device(device);
return ret;
}
dev_set_drvdata(&cdev->dev, device);
cdev->handler = __tape_do_irq;
device->cdev = cdev;
ccw_device_get_id(cdev, &dev_id);
device->cdev_id = devid_to_int(&dev_id);
return ret;
}
static void
__tape_discard_requests(struct tape_device *device)
{
struct tape_request * request;
struct list_head * l, *n;
list_for_each_safe(l, n, &device->req_queue) {
request = list_entry(l, struct tape_request, list);
if (request->status == TAPE_REQUEST_IN_IO)
request->status = TAPE_REQUEST_DONE;
list_del(&request->list);
/* Decrease ref_count for removed request. */
request->device = NULL;
tape_put_device(device);
request->rc = -EIO;
if (request->callback != NULL)
request->callback(request, request->callback_data);
}
}
/*
* Driverfs tape remove function.
*
* This function is called whenever the common I/O layer detects the device
* gone. This can happen at any time and we cannot refuse.
*/
void
tape_generic_remove(struct ccw_device *cdev)
{
struct tape_device * device;
device = dev_get_drvdata(&cdev->dev);
if (!device) {
return;
}
DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
spin_lock_irq(get_ccwdev_lock(device->cdev));
switch (device->tape_state) {
case TS_INIT:
tape_state_set(device, TS_NOT_OPER);
case TS_NOT_OPER:
/*
* Nothing to do.
*/
spin_unlock_irq(get_ccwdev_lock(device->cdev));
break;
case TS_UNUSED:
/*
* Need only to release the device.
*/
tape_state_set(device, TS_NOT_OPER);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
tape_cleanup_device(device);
break;
default:
/*
* There may be requests on the queue. We will not get
* an interrupt for a request that was running. So we
* just post them all as I/O errors.
*/
DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
device->cdev_id);
pr_warning("%s: A tape unit was detached while in "
"use\n", dev_name(&device->cdev->dev));
tape_state_set(device, TS_NOT_OPER);
__tape_discard_requests(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
tape_cleanup_device(device);
}
device = dev_get_drvdata(&cdev->dev);
if (device) {
sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
dev_set_drvdata(&cdev->dev, NULL);
tape_put_device(device);
}
}
/*
* Allocate a new tape ccw request
*/
struct tape_request *
tape_alloc_request(int cplength, int datasize)
{
struct tape_request *request;
BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
if (request == NULL) {
DBF_EXCEPTION(1, "cqra nomem\n");
return ERR_PTR(-ENOMEM);
}
/* allocate channel program */
if (cplength > 0) {
request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
GFP_ATOMIC | GFP_DMA);
if (request->cpaddr == NULL) {
DBF_EXCEPTION(1, "cqra nomem\n");
kfree(request);
return ERR_PTR(-ENOMEM);
}
}
/* alloc small kernel buffer */
if (datasize > 0) {
request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
if (request->cpdata == NULL) {
DBF_EXCEPTION(1, "cqra nomem\n");
kfree(request->cpaddr);
kfree(request);
return ERR_PTR(-ENOMEM);
}
}
DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
request->cpdata);
return request;
}
/*
* Free tape ccw request
*/
void
tape_free_request (struct tape_request * request)
{
DBF_LH(6, "Free request %p\n", request);
if (request->device)
tape_put_device(request->device);
kfree(request->cpdata);
kfree(request->cpaddr);
kfree(request);
}
static int
__tape_start_io(struct tape_device *device, struct tape_request *request)
{
int rc;
rc = ccw_device_start(
device->cdev,
request->cpaddr,
(unsigned long) request,
0x00,
request->options
);
if (rc == 0) {
request->status = TAPE_REQUEST_IN_IO;
} else if (rc == -EBUSY) {
/* The common I/O subsystem is currently busy. Retry later. */
request->status = TAPE_REQUEST_QUEUED;
schedule_delayed_work(&device->tape_dnr, 0);
rc = 0;
} else {
/* Start failed. Remove request and indicate failure. */
DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
}
return rc;
}
static void
__tape_start_next_request(struct tape_device *device)
{
struct list_head *l, *n;
struct tape_request *request;
int rc;
DBF_LH(6, "__tape_start_next_request(%p)\n", device);
/*
* Try to start each request on request queue until one is
* started successful.
*/
list_for_each_safe(l, n, &device->req_queue) {
request = list_entry(l, struct tape_request, list);
/*
* Avoid race condition if bottom-half was triggered more than
* once.
*/
if (request->status == TAPE_REQUEST_IN_IO)
return;
/*
* Request has already been stopped. We have to wait until
* the request is removed from the queue in the interrupt
* handling.
*/
if (request->status == TAPE_REQUEST_DONE)
return;
/*
* We wanted to cancel the request but the common I/O layer
* was busy at that time. This can only happen if this
* function is called by delayed_next_request.
* Otherwise we start the next request on the queue.
*/
if (request->status == TAPE_REQUEST_CANCEL) {
rc = __tape_cancel_io(device, request);
} else {
rc = __tape_start_io(device, request);
}
if (rc == 0)
return;
/* Set ending status. */
request->rc = rc;
request->status = TAPE_REQUEST_DONE;
/* Remove from request queue. */
list_del(&request->list);
/* Do callback. */
if (request->callback != NULL)
request->callback(request, request->callback_data);
}
}
static void
tape_delayed_next_request(struct work_struct *work)
{
struct tape_device *device =
container_of(work, struct tape_device, tape_dnr.work);
DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
spin_lock_irq(get_ccwdev_lock(device->cdev));
__tape_start_next_request(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
}
static void tape_long_busy_timeout(unsigned long data)
{
struct tape_request *request;
struct tape_device *device;
device = (struct tape_device *) data;
spin_lock_irq(get_ccwdev_lock(device->cdev));
request = list_entry(device->req_queue.next, struct tape_request, list);
BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
__tape_start_next_request(device);
device->lb_timeout.data = 0UL;
tape_put_device(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
}
static void
__tape_end_request(
struct tape_device * device,
struct tape_request * request,
int rc)
{
DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
if (request) {
request->rc = rc;
request->status = TAPE_REQUEST_DONE;
/* Remove from request queue. */
list_del(&request->list);
/* Do callback. */
if (request->callback != NULL)
request->callback(request, request->callback_data);
}
/* Start next request. */
if (!list_empty(&device->req_queue))
__tape_start_next_request(device);
}
/*
* Write sense data to dbf
*/
void
tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
struct irb *irb)
{
unsigned int *sptr;
const char* op;
if (request != NULL)
op = tape_op_verbose[request->op];
else
op = "---";
DBF_EVENT(3, "DSTAT : %02x CSTAT: %02x\n",
irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
sptr = (unsigned int *) irb->ecw;
DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
}
/*
* I/O helper function. Adds the request to the request queue
* and starts it if the tape is idle. Has to be called with
* the device lock held.
*/
static int
__tape_start_request(struct tape_device *device, struct tape_request *request)
{
int rc;
switch (request->op) {
case TO_MSEN:
case TO_ASSIGN:
case TO_UNASSIGN:
case TO_READ_ATTMSG:
case TO_RDC:
if (device->tape_state == TS_INIT)
break;
if (device->tape_state == TS_UNUSED)
break;
default:
if (device->tape_state == TS_BLKUSE)
break;
if (device->tape_state != TS_IN_USE)
return -ENODEV;
}
/* Increase use count of device for the added request. */
request->device = tape_get_device(device);
if (list_empty(&device->req_queue)) {
/* No other requests are on the queue. Start this one. */
rc = __tape_start_io(device, request);
if (rc)
return rc;
DBF_LH(5, "Request %p added for execution.\n", request);
list_add(&request->list, &device->req_queue);
} else {
DBF_LH(5, "Request %p add to queue.\n", request);
request->status = TAPE_REQUEST_QUEUED;
list_add_tail(&request->list, &device->req_queue);
}
return 0;
}
/*
* Add the request to the request queue, try to start it if the
* tape is idle. Return without waiting for end of i/o.
*/
int
tape_do_io_async(struct tape_device *device, struct tape_request *request)
{
int rc;
DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* Add request to request queue and try to start it. */
rc = __tape_start_request(device, request);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
/*
* tape_do_io/__tape_wake_up
* Add the request to the request queue, try to start it if the
* tape is idle and wait uninterruptible for its completion.
*/
static void
__tape_wake_up(struct tape_request *request, void *data)
{
request->callback = NULL;
wake_up((wait_queue_head_t *) data);
}
int
tape_do_io(struct tape_device *device, struct tape_request *request)
{
int rc;
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* Setup callback */
request->callback = __tape_wake_up;
request->callback_data = &device->wait_queue;
/* Add request to request queue and try to start it. */
rc = __tape_start_request(device, request);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
if (rc)
return rc;
/* Request added to the queue. Wait for its completion. */
wait_event(device->wait_queue, (request->callback == NULL));
/* Get rc from request */
return request->rc;
}
/*
* tape_do_io_interruptible/__tape_wake_up_interruptible
* Add the request to the request queue, try to start it if the
* tape is idle and wait uninterruptible for its completion.
*/
static void
__tape_wake_up_interruptible(struct tape_request *request, void *data)
{
request->callback = NULL;
wake_up_interruptible((wait_queue_head_t *) data);
}
int
tape_do_io_interruptible(struct tape_device *device,
struct tape_request *request)
{
int rc;
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* Setup callback */
request->callback = __tape_wake_up_interruptible;
request->callback_data = &device->wait_queue;
rc = __tape_start_request(device, request);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
if (rc)
return rc;
/* Request added to the queue. Wait for its completion. */
rc = wait_event_interruptible(device->wait_queue,
(request->callback == NULL));
if (rc != -ERESTARTSYS)
/* Request finished normally. */
return request->rc;
/* Interrupted by a signal. We have to stop the current request. */
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = __tape_cancel_io(device, request);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
if (rc == 0) {
/* Wait for the interrupt that acknowledges the halt. */
do {
rc = wait_event_interruptible(
device->wait_queue,
(request->callback == NULL)
);
} while (rc == -ERESTARTSYS);
DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
rc = -ERESTARTSYS;
}
return rc;
}
/*
* Stop running ccw.
*/
int
tape_cancel_io(struct tape_device *device, struct tape_request *request)
{
int rc;
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = __tape_cancel_io(device, request);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
/*
* Tape interrupt routine, called from the ccw_device layer
*/
static void
__tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
{
struct tape_device *device;
struct tape_request *request;
int rc;
device = dev_get_drvdata(&cdev->dev);
if (device == NULL) {
return;
}
request = (struct tape_request *) intparm;
DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
/* On special conditions irb is an error pointer */
if (IS_ERR(irb)) {
/* FIXME: What to do with the request? */
switch (PTR_ERR(irb)) {
case -ETIMEDOUT:
DBF_LH(1, "(%08x): Request timed out\n",
device->cdev_id);
case -EIO:
__tape_end_request(device, request, -EIO);
break;
default:
DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
device->cdev_id, PTR_ERR(irb));
}
return;
}
/*
* If the condition code is not zero and the start function bit is
* still set, this is an deferred error and the last start I/O did
* not succeed. At this point the condition that caused the deferred
* error might still apply. So we just schedule the request to be
* started later.
*/
if (irb->scsw.cmd.cc != 0 &&
(irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
(request->status == TAPE_REQUEST_IN_IO)) {
DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
request->status = TAPE_REQUEST_QUEUED;
schedule_delayed_work(&device->tape_dnr, HZ);
return;
}
/* May be an unsolicited irq */
if(request != NULL)
request->rescnt = irb->scsw.cmd.count;
else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
!list_empty(&device->req_queue)) {
/* Not Ready to Ready after long busy ? */
struct tape_request *req;
req = list_entry(device->req_queue.next,
struct tape_request, list);
if (req->status == TAPE_REQUEST_LONG_BUSY) {
DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
if (del_timer(&device->lb_timeout)) {
device->lb_timeout.data = 0UL;
tape_put_device(device);
__tape_start_next_request(device);
}
return;
}
}
if (irb->scsw.cmd.dstat != 0x0c) {
/* Set the 'ONLINE' flag depending on sense byte 1 */
if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
device->tape_generic_status |= GMT_ONLINE(~0);
else
device->tape_generic_status &= ~GMT_ONLINE(~0);
/*
* Any request that does not come back with channel end
* and device end is unusual. Log the sense data.
*/
DBF_EVENT(3,"-- Tape Interrupthandler --\n");
tape_dump_sense_dbf(device, request, irb);
} else {
/* Upon normal completion the device _is_ online */
device->tape_generic_status |= GMT_ONLINE(~0);
}
if (device->tape_state == TS_NOT_OPER) {
DBF_EVENT(6, "tape:device is not operational\n");
return;
}
/*
* Request that were canceled still come back with an interrupt.
* To detect these request the state will be set to TAPE_REQUEST_DONE.
*/
if(request != NULL && request->status == TAPE_REQUEST_DONE) {
__tape_end_request(device, request, -EIO);
return;
}
rc = device->discipline->irq(device, request, irb);
/*
* rc < 0 : request finished unsuccessfully.
* rc == TAPE_IO_SUCCESS: request finished successfully.
* rc == TAPE_IO_PENDING: request is still running. Ignore rc.
* rc == TAPE_IO_RETRY: request finished but needs another go.
* rc == TAPE_IO_STOP: request needs to get terminated.
*/
switch (rc) {
case TAPE_IO_SUCCESS:
/* Upon normal completion the device _is_ online */
device->tape_generic_status |= GMT_ONLINE(~0);
__tape_end_request(device, request, rc);
break;
case TAPE_IO_PENDING:
break;
case TAPE_IO_LONG_BUSY:
device->lb_timeout.data =
(unsigned long) tape_get_device(device);
device->lb_timeout.expires = jiffies +
LONG_BUSY_TIMEOUT * HZ;
DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
add_timer(&device->lb_timeout);
request->status = TAPE_REQUEST_LONG_BUSY;
break;
case TAPE_IO_RETRY:
rc = __tape_start_io(device, request);
if (rc)
__tape_end_request(device, request, rc);
break;
case TAPE_IO_STOP:
rc = __tape_cancel_io(device, request);
if (rc)
__tape_end_request(device, request, rc);
break;
default:
if (rc > 0) {
DBF_EVENT(6, "xunknownrc\n");
__tape_end_request(device, request, -EIO);
} else {
__tape_end_request(device, request, rc);
}
break;
}
}
/*
* Tape device open function used by tape_char frontend.
*/
int
tape_open(struct tape_device *device)
{
int rc;
spin_lock_irq(get_ccwdev_lock(device->cdev));
if (device->tape_state == TS_NOT_OPER) {
DBF_EVENT(6, "TAPE:nodev\n");
rc = -ENODEV;
} else if (device->tape_state == TS_IN_USE) {
DBF_EVENT(6, "TAPE:dbusy\n");
rc = -EBUSY;
} else if (device->tape_state == TS_BLKUSE) {
DBF_EVENT(6, "TAPE:dbusy\n");
rc = -EBUSY;
} else if (device->discipline != NULL &&
!try_module_get(device->discipline->owner)) {
DBF_EVENT(6, "TAPE:nodisc\n");
rc = -ENODEV;
} else {
tape_state_set(device, TS_IN_USE);
rc = 0;
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
/*
* Tape device release function used by tape_char frontend.
*/
int
tape_release(struct tape_device *device)
{
spin_lock_irq(get_ccwdev_lock(device->cdev));
if (device->tape_state == TS_IN_USE)
tape_state_set(device, TS_UNUSED);
module_put(device->discipline->owner);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return 0;
}
/*
* Execute a magnetic tape command a number of times.
*/
int
tape_mtop(struct tape_device *device, int mt_op, int mt_count)
{
tape_mtop_fn fn;
int rc;
DBF_EVENT(6, "TAPE:mtio\n");
DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
DBF_EVENT(6, "TAPE:arg: %x\n", mt_count);
if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
return -EINVAL;
fn = device->discipline->mtop_array[mt_op];
if (fn == NULL)
return -EINVAL;
/* We assume that the backends can handle count up to 500. */
if (mt_op == MTBSR || mt_op == MTFSR || mt_op == MTFSF ||
mt_op == MTBSF || mt_op == MTFSFM || mt_op == MTBSFM) {
rc = 0;
for (; mt_count > 500; mt_count -= 500)
if ((rc = fn(device, 500)) != 0)
break;
if (rc == 0)
rc = fn(device, mt_count);
} else
rc = fn(device, mt_count);
return rc;
}
/*
* Tape init function.
*/
static int
tape_init (void)
{
TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
#ifdef DBF_LIKE_HELL
debug_set_level(TAPE_DBF_AREA, 6);
#endif
DBF_EVENT(3, "tape init\n");
tape_proc_init();
tapechar_init ();
return 0;
}
/*
* Tape exit function.
*/
static void
tape_exit(void)
{
DBF_EVENT(6, "tape exit\n");
/* Get rid of the frontends */
tapechar_exit();
tape_proc_cleanup();
debug_unregister (TAPE_DBF_AREA);
}
MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
"Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
MODULE_LICENSE("GPL");
module_init(tape_init);
module_exit(tape_exit);
EXPORT_SYMBOL(tape_generic_remove);
EXPORT_SYMBOL(tape_generic_probe);
EXPORT_SYMBOL(tape_generic_online);
EXPORT_SYMBOL(tape_generic_offline);
EXPORT_SYMBOL(tape_generic_pm_suspend);
EXPORT_SYMBOL(tape_put_device);
EXPORT_SYMBOL(tape_get_device);
EXPORT_SYMBOL(tape_state_verbose);
EXPORT_SYMBOL(tape_op_verbose);
EXPORT_SYMBOL(tape_state_set);
EXPORT_SYMBOL(tape_med_state_set);
EXPORT_SYMBOL(tape_alloc_request);
EXPORT_SYMBOL(tape_free_request);
EXPORT_SYMBOL(tape_dump_sense_dbf);
EXPORT_SYMBOL(tape_do_io);
EXPORT_SYMBOL(tape_do_io_async);
EXPORT_SYMBOL(tape_do_io_interruptible);
EXPORT_SYMBOL(tape_cancel_io);
EXPORT_SYMBOL(tape_mtop);