Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / s390 / cio / device_ops.c
diff --git a/kernel/drivers/s390/cio/device_ops.c b/kernel/drivers/s390/cio/device_ops.c
new file mode 100644 (file)
index 0000000..f3c4179
--- /dev/null
@@ -0,0 +1,799 @@
+/*
+ * Copyright IBM Corp. 2002, 2009
+ *
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *           Cornelia Huck (cornelia.huck@de.ibm.com)
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
+
+#include <asm/ccwdev.h>
+#include <asm/idals.h>
+#include <asm/chpid.h>
+#include <asm/fcx.h>
+
+#include "cio.h"
+#include "cio_debug.h"
+#include "css.h"
+#include "chsc.h"
+#include "device.h"
+#include "chp.h"
+
+/**
+ * ccw_device_set_options_mask() - set some options and unset the rest
+ * @cdev: device for which the options are to be set
+ * @flags: options to be set
+ *
+ * All flags specified in @flags are set, all flags not specified in @flags
+ * are cleared.
+ * Returns:
+ *   %0 on success, -%EINVAL on an invalid flag combination.
+ */
+int ccw_device_set_options_mask(struct ccw_device *cdev, unsigned long flags)
+{
+       /*
+       * The flag usage is mutal exclusive ...
+       */
+       if ((flags & CCWDEV_EARLY_NOTIFICATION) &&
+           (flags & CCWDEV_REPORT_ALL))
+               return -EINVAL;
+       cdev->private->options.fast = (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
+       cdev->private->options.repall = (flags & CCWDEV_REPORT_ALL) != 0;
+       cdev->private->options.pgroup = (flags & CCWDEV_DO_PATHGROUP) != 0;
+       cdev->private->options.force = (flags & CCWDEV_ALLOW_FORCE) != 0;
+       cdev->private->options.mpath = (flags & CCWDEV_DO_MULTIPATH) != 0;
+       return 0;
+}
+
+/**
+ * ccw_device_set_options() - set some options
+ * @cdev: device for which the options are to be set
+ * @flags: options to be set
+ *
+ * All flags specified in @flags are set, the remainder is left untouched.
+ * Returns:
+ *   %0 on success, -%EINVAL if an invalid flag combination would ensue.
+ */
+int ccw_device_set_options(struct ccw_device *cdev, unsigned long flags)
+{
+       /*
+       * The flag usage is mutal exclusive ...
+       */
+       if (((flags & CCWDEV_EARLY_NOTIFICATION) &&
+           (flags & CCWDEV_REPORT_ALL)) ||
+           ((flags & CCWDEV_EARLY_NOTIFICATION) &&
+            cdev->private->options.repall) ||
+           ((flags & CCWDEV_REPORT_ALL) &&
+            cdev->private->options.fast))
+               return -EINVAL;
+       cdev->private->options.fast |= (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
+       cdev->private->options.repall |= (flags & CCWDEV_REPORT_ALL) != 0;
+       cdev->private->options.pgroup |= (flags & CCWDEV_DO_PATHGROUP) != 0;
+       cdev->private->options.force |= (flags & CCWDEV_ALLOW_FORCE) != 0;
+       cdev->private->options.mpath |= (flags & CCWDEV_DO_MULTIPATH) != 0;
+       return 0;
+}
+
+/**
+ * ccw_device_clear_options() - clear some options
+ * @cdev: device for which the options are to be cleared
+ * @flags: options to be cleared
+ *
+ * All flags specified in @flags are cleared, the remainder is left untouched.
+ */
+void ccw_device_clear_options(struct ccw_device *cdev, unsigned long flags)
+{
+       cdev->private->options.fast &= (flags & CCWDEV_EARLY_NOTIFICATION) == 0;
+       cdev->private->options.repall &= (flags & CCWDEV_REPORT_ALL) == 0;
+       cdev->private->options.pgroup &= (flags & CCWDEV_DO_PATHGROUP) == 0;
+       cdev->private->options.force &= (flags & CCWDEV_ALLOW_FORCE) == 0;
+       cdev->private->options.mpath &= (flags & CCWDEV_DO_MULTIPATH) == 0;
+}
+
+/**
+ * ccw_device_is_pathgroup - determine if paths to this device are grouped
+ * @cdev: ccw device
+ *
+ * Return non-zero if there is a path group, zero otherwise.
+ */
+int ccw_device_is_pathgroup(struct ccw_device *cdev)
+{
+       return cdev->private->flags.pgroup;
+}
+EXPORT_SYMBOL(ccw_device_is_pathgroup);
+
+/**
+ * ccw_device_is_multipath - determine if device is operating in multipath mode
+ * @cdev: ccw device
+ *
+ * Return non-zero if device is operating in multipath mode, zero otherwise.
+ */
+int ccw_device_is_multipath(struct ccw_device *cdev)
+{
+       return cdev->private->flags.mpath;
+}
+EXPORT_SYMBOL(ccw_device_is_multipath);
+
+/**
+ * ccw_device_clear() - terminate I/O request processing
+ * @cdev: target ccw device
+ * @intparm: interruption parameter; value is only used if no I/O is
+ *          outstanding, otherwise the intparm associated with the I/O request
+ *          is returned
+ *
+ * ccw_device_clear() calls csch on @cdev's subchannel.
+ * Returns:
+ *  %0 on success,
+ *  -%ENODEV on device not operational,
+ *  -%EINVAL on invalid device state.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
+{
+       struct subchannel *sch;
+       int ret;
+
+       if (!cdev || !cdev->dev.parent)
+               return -ENODEV;
+       sch = to_subchannel(cdev->dev.parent);
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state == DEV_STATE_NOT_OPER)
+               return -ENODEV;
+       if (cdev->private->state != DEV_STATE_ONLINE &&
+           cdev->private->state != DEV_STATE_W4SENSE)
+               return -EINVAL;
+
+       ret = cio_clear(sch);
+       if (ret == 0)
+               cdev->private->intparm = intparm;
+       return ret;
+}
+
+/**
+ * ccw_device_start_key() - start a s390 channel program with key
+ * @cdev: target ccw device
+ * @cpa: logical start address of channel program
+ * @intparm: user specific interruption parameter; will be presented back to
+ *          @cdev's interrupt handler. Allows a device driver to associate
+ *          the interrupt with a particular I/O request.
+ * @lpm: defines the channel path to be used for a specific I/O request. A
+ *      value of 0 will make cio use the opm.
+ * @key: storage key to be used for the I/O
+ * @flags: additional flags; defines the action to be performed for I/O
+ *        processing.
+ *
+ * Start a S/390 channel program. When the interrupt arrives, the
+ * IRQ handler is called, either immediately, delayed (dev-end missing,
+ * or sense required) or never (no IRQ handler registered).
+ * Returns:
+ *  %0, if the operation was successful;
+ *  -%EBUSY, if the device is busy, or status pending;
+ *  -%EACCES, if no path specified in @lpm is operational;
+ *  -%ENODEV, if the device is not operational.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
+                        unsigned long intparm, __u8 lpm, __u8 key,
+                        unsigned long flags)
+{
+       struct subchannel *sch;
+       int ret;
+
+       if (!cdev || !cdev->dev.parent)
+               return -ENODEV;
+       sch = to_subchannel(cdev->dev.parent);
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state == DEV_STATE_NOT_OPER)
+               return -ENODEV;
+       if (cdev->private->state == DEV_STATE_VERIFY) {
+               /* Remember to fake irb when finished. */
+               if (!cdev->private->flags.fake_irb) {
+                       cdev->private->flags.fake_irb = FAKE_CMD_IRB;
+                       cdev->private->intparm = intparm;
+                       return 0;
+               } else
+                       /* There's already a fake I/O around. */
+                       return -EBUSY;
+       }
+       if (cdev->private->state != DEV_STATE_ONLINE ||
+           ((sch->schib.scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) &&
+            !(sch->schib.scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS)) ||
+           cdev->private->flags.doverify)
+               return -EBUSY;
+       ret = cio_set_options (sch, flags);
+       if (ret)
+               return ret;
+       /* Adjust requested path mask to exclude unusable paths. */
+       if (lpm) {
+               lpm &= sch->lpm;
+               if (lpm == 0)
+                       return -EACCES;
+       }
+       ret = cio_start_key (sch, cpa, lpm, key);
+       switch (ret) {
+       case 0:
+               cdev->private->intparm = intparm;
+               break;
+       case -EACCES:
+       case -ENODEV:
+               dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+               break;
+       }
+       return ret;
+}
+
+/**
+ * ccw_device_start_timeout_key() - start a s390 channel program with timeout and key
+ * @cdev: target ccw device
+ * @cpa: logical start address of channel program
+ * @intparm: user specific interruption parameter; will be presented back to
+ *          @cdev's interrupt handler. Allows a device driver to associate
+ *          the interrupt with a particular I/O request.
+ * @lpm: defines the channel path to be used for a specific I/O request. A
+ *      value of 0 will make cio use the opm.
+ * @key: storage key to be used for the I/O
+ * @flags: additional flags; defines the action to be performed for I/O
+ *        processing.
+ * @expires: timeout value in jiffies
+ *
+ * Start a S/390 channel program. When the interrupt arrives, the
+ * IRQ handler is called, either immediately, delayed (dev-end missing,
+ * or sense required) or never (no IRQ handler registered).
+ * This function notifies the device driver if the channel program has not
+ * completed during the time specified by @expires. If a timeout occurs, the
+ * channel program is terminated via xsch, hsch or csch, and the device's
+ * interrupt handler will be called with an irb containing ERR_PTR(-%ETIMEDOUT).
+ * Returns:
+ *  %0, if the operation was successful;
+ *  -%EBUSY, if the device is busy, or status pending;
+ *  -%EACCES, if no path specified in @lpm is operational;
+ *  -%ENODEV, if the device is not operational.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_start_timeout_key(struct ccw_device *cdev, struct ccw1 *cpa,
+                                unsigned long intparm, __u8 lpm, __u8 key,
+                                unsigned long flags, int expires)
+{
+       int ret;
+
+       if (!cdev)
+               return -ENODEV;
+       ccw_device_set_timeout(cdev, expires);
+       ret = ccw_device_start_key(cdev, cpa, intparm, lpm, key, flags);
+       if (ret != 0)
+               ccw_device_set_timeout(cdev, 0);
+       return ret;
+}
+
+/**
+ * ccw_device_start() - start a s390 channel program
+ * @cdev: target ccw device
+ * @cpa: logical start address of channel program
+ * @intparm: user specific interruption parameter; will be presented back to
+ *          @cdev's interrupt handler. Allows a device driver to associate
+ *          the interrupt with a particular I/O request.
+ * @lpm: defines the channel path to be used for a specific I/O request. A
+ *      value of 0 will make cio use the opm.
+ * @flags: additional flags; defines the action to be performed for I/O
+ *        processing.
+ *
+ * Start a S/390 channel program. When the interrupt arrives, the
+ * IRQ handler is called, either immediately, delayed (dev-end missing,
+ * or sense required) or never (no IRQ handler registered).
+ * Returns:
+ *  %0, if the operation was successful;
+ *  -%EBUSY, if the device is busy, or status pending;
+ *  -%EACCES, if no path specified in @lpm is operational;
+ *  -%ENODEV, if the device is not operational.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_start(struct ccw_device *cdev, struct ccw1 *cpa,
+                    unsigned long intparm, __u8 lpm, unsigned long flags)
+{
+       return ccw_device_start_key(cdev, cpa, intparm, lpm,
+                                   PAGE_DEFAULT_KEY, flags);
+}
+
+/**
+ * ccw_device_start_timeout() - start a s390 channel program with timeout
+ * @cdev: target ccw device
+ * @cpa: logical start address of channel program
+ * @intparm: user specific interruption parameter; will be presented back to
+ *          @cdev's interrupt handler. Allows a device driver to associate
+ *          the interrupt with a particular I/O request.
+ * @lpm: defines the channel path to be used for a specific I/O request. A
+ *      value of 0 will make cio use the opm.
+ * @flags: additional flags; defines the action to be performed for I/O
+ *        processing.
+ * @expires: timeout value in jiffies
+ *
+ * Start a S/390 channel program. When the interrupt arrives, the
+ * IRQ handler is called, either immediately, delayed (dev-end missing,
+ * or sense required) or never (no IRQ handler registered).
+ * This function notifies the device driver if the channel program has not
+ * completed during the time specified by @expires. If a timeout occurs, the
+ * channel program is terminated via xsch, hsch or csch, and the device's
+ * interrupt handler will be called with an irb containing ERR_PTR(-%ETIMEDOUT).
+ * Returns:
+ *  %0, if the operation was successful;
+ *  -%EBUSY, if the device is busy, or status pending;
+ *  -%EACCES, if no path specified in @lpm is operational;
+ *  -%ENODEV, if the device is not operational.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_start_timeout(struct ccw_device *cdev, struct ccw1 *cpa,
+                            unsigned long intparm, __u8 lpm,
+                            unsigned long flags, int expires)
+{
+       return ccw_device_start_timeout_key(cdev, cpa, intparm, lpm,
+                                           PAGE_DEFAULT_KEY, flags,
+                                           expires);
+}
+
+
+/**
+ * ccw_device_halt() - halt I/O request processing
+ * @cdev: target ccw device
+ * @intparm: interruption parameter; value is only used if no I/O is
+ *          outstanding, otherwise the intparm associated with the I/O request
+ *          is returned
+ *
+ * ccw_device_halt() calls hsch on @cdev's subchannel.
+ * Returns:
+ *  %0 on success,
+ *  -%ENODEV on device not operational,
+ *  -%EINVAL on invalid device state,
+ *  -%EBUSY on device busy or interrupt pending.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_halt(struct ccw_device *cdev, unsigned long intparm)
+{
+       struct subchannel *sch;
+       int ret;
+
+       if (!cdev || !cdev->dev.parent)
+               return -ENODEV;
+       sch = to_subchannel(cdev->dev.parent);
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state == DEV_STATE_NOT_OPER)
+               return -ENODEV;
+       if (cdev->private->state != DEV_STATE_ONLINE &&
+           cdev->private->state != DEV_STATE_W4SENSE)
+               return -EINVAL;
+
+       ret = cio_halt(sch);
+       if (ret == 0)
+               cdev->private->intparm = intparm;
+       return ret;
+}
+
+/**
+ * ccw_device_resume() - resume channel program execution
+ * @cdev: target ccw device
+ *
+ * ccw_device_resume() calls rsch on @cdev's subchannel.
+ * Returns:
+ *  %0 on success,
+ *  -%ENODEV on device not operational,
+ *  -%EINVAL on invalid device state,
+ *  -%EBUSY on device busy or interrupt pending.
+ * Context:
+ *  Interrupts disabled, ccw device lock held
+ */
+int ccw_device_resume(struct ccw_device *cdev)
+{
+       struct subchannel *sch;
+
+       if (!cdev || !cdev->dev.parent)
+               return -ENODEV;
+       sch = to_subchannel(cdev->dev.parent);
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state == DEV_STATE_NOT_OPER)
+               return -ENODEV;
+       if (cdev->private->state != DEV_STATE_ONLINE ||
+           !(sch->schib.scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
+               return -EINVAL;
+       return cio_resume(sch);
+}
+
+/*
+ * Pass interrupt to device driver.
+ */
+int
+ccw_device_call_handler(struct ccw_device *cdev)
+{
+       unsigned int stctl;
+       int ending_status;
+
+       /*
+        * we allow for the device action handler if .
+        *  - we received ending status
+        *  - the action handler requested to see all interrupts
+        *  - we received an intermediate status
+        *  - fast notification was requested (primary status)
+        *  - unsolicited interrupts
+        */
+       stctl = scsw_stctl(&cdev->private->irb.scsw);
+       ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
+               (stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
+               (stctl == SCSW_STCTL_STATUS_PEND);
+       if (!ending_status &&
+           !cdev->private->options.repall &&
+           !(stctl & SCSW_STCTL_INTER_STATUS) &&
+           !(cdev->private->options.fast &&
+             (stctl & SCSW_STCTL_PRIM_STATUS)))
+               return 0;
+
+       /* Clear pending timers for device driver initiated I/O. */
+       if (ending_status)
+               ccw_device_set_timeout(cdev, 0);
+       /*
+        * Now we are ready to call the device driver interrupt handler.
+        */
+       if (cdev->handler)
+               cdev->handler(cdev, cdev->private->intparm,
+                             &cdev->private->irb);
+
+       /*
+        * Clear the old and now useless interrupt response block.
+        */
+       memset(&cdev->private->irb, 0, sizeof(struct irb));
+
+       return 1;
+}
+
+/**
+ * ccw_device_get_ciw() - Search for CIW command in extended sense data.
+ * @cdev: ccw device to inspect
+ * @ct: command type to look for
+ *
+ * During SenseID, command information words (CIWs) describing special
+ * commands available to the device may have been stored in the extended
+ * sense data. This function searches for CIWs of a specified command
+ * type in the extended sense data.
+ * Returns:
+ *  %NULL if no extended sense data has been stored or if no CIW of the
+ *  specified command type could be found,
+ *  else a pointer to the CIW of the specified command type.
+ */
+struct ciw *ccw_device_get_ciw(struct ccw_device *cdev, __u32 ct)
+{
+       int ciw_cnt;
+
+       if (cdev->private->flags.esid == 0)
+               return NULL;
+       for (ciw_cnt = 0; ciw_cnt < MAX_CIWS; ciw_cnt++)
+               if (cdev->private->senseid.ciw[ciw_cnt].ct == ct)
+                       return cdev->private->senseid.ciw + ciw_cnt;
+       return NULL;
+}
+
+/**
+ * ccw_device_get_path_mask() - get currently available paths
+ * @cdev: ccw device to be queried
+ * Returns:
+ *  %0 if no subchannel for the device is available,
+ *  else the mask of currently available paths for the ccw device's subchannel.
+ */
+__u8 ccw_device_get_path_mask(struct ccw_device *cdev)
+{
+       struct subchannel *sch;
+
+       if (!cdev->dev.parent)
+               return 0;
+
+       sch = to_subchannel(cdev->dev.parent);
+       return sch->lpm;
+}
+
+struct stlck_data {
+       struct completion done;
+       int rc;
+};
+
+void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc)
+{
+       struct stlck_data *sdata = data;
+
+       sdata->rc = rc;
+       complete(&sdata->done);
+}
+
+/*
+ * Perform unconditional reserve + release.
+ */
+int ccw_device_stlck(struct ccw_device *cdev)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+       struct stlck_data data;
+       u8 *buffer;
+       int rc;
+
+       /* Check if steal lock operation is valid for this device. */
+       if (cdev->drv) {
+               if (!cdev->private->options.force)
+                       return -EINVAL;
+       }
+       buffer = kzalloc(64, GFP_DMA | GFP_KERNEL);
+       if (!buffer)
+               return -ENOMEM;
+       init_completion(&data.done);
+       data.rc = -EIO;
+       spin_lock_irq(sch->lock);
+       rc = cio_enable_subchannel(sch, (u32) (addr_t) sch);
+       if (rc)
+               goto out_unlock;
+       /* Perform operation. */
+       cdev->private->state = DEV_STATE_STEAL_LOCK,
+       ccw_device_stlck_start(cdev, &data, &buffer[0], &buffer[32]);
+       spin_unlock_irq(sch->lock);
+       /* Wait for operation to finish. */
+       if (wait_for_completion_interruptible(&data.done)) {
+               /* Got a signal. */
+               spin_lock_irq(sch->lock);
+               ccw_request_cancel(cdev);
+               spin_unlock_irq(sch->lock);
+               wait_for_completion(&data.done);
+       }
+       rc = data.rc;
+       /* Check results. */
+       spin_lock_irq(sch->lock);
+       cio_disable_subchannel(sch);
+       cdev->private->state = DEV_STATE_BOXED;
+out_unlock:
+       spin_unlock_irq(sch->lock);
+       kfree(buffer);
+
+       return rc;
+}
+
+/**
+ * chp_get_chp_desc - return newly allocated channel-path descriptor
+ * @cdev: device to obtain the descriptor for
+ * @chp_idx: index of the channel path
+ *
+ * On success return a newly allocated copy of the channel-path description
+ * data associated with the given channel path. Return %NULL on error.
+ */
+struct channel_path_desc *ccw_device_get_chp_desc(struct ccw_device *cdev,
+                                                 int chp_idx)
+{
+       struct subchannel *sch;
+       struct chp_id chpid;
+
+       sch = to_subchannel(cdev->dev.parent);
+       chp_id_init(&chpid);
+       chpid.id = sch->schib.pmcw.chpid[chp_idx];
+       return chp_get_chp_desc(chpid);
+}
+
+/**
+ * ccw_device_get_id - obtain a ccw device id
+ * @cdev: device to obtain the id for
+ * @dev_id: where to fill in the values
+ */
+void ccw_device_get_id(struct ccw_device *cdev, struct ccw_dev_id *dev_id)
+{
+       *dev_id = cdev->private->dev_id;
+}
+EXPORT_SYMBOL(ccw_device_get_id);
+
+/**
+ * ccw_device_tm_start_key - perform start function
+ * @cdev: ccw device on which to perform the start function
+ * @tcw: transport-command word to be started
+ * @intparm: user defined parameter to be passed to the interrupt handler
+ * @lpm: mask of paths to use
+ * @key: storage key to use for storage access
+ *
+ * Start the tcw on the given ccw device. Return zero on success, non-zero
+ * otherwise.
+ */
+int ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
+                           unsigned long intparm, u8 lpm, u8 key)
+{
+       struct subchannel *sch;
+       int rc;
+
+       sch = to_subchannel(cdev->dev.parent);
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state == DEV_STATE_VERIFY) {
+               /* Remember to fake irb when finished. */
+               if (!cdev->private->flags.fake_irb) {
+                       cdev->private->flags.fake_irb = FAKE_TM_IRB;
+                       cdev->private->intparm = intparm;
+                       return 0;
+               } else
+                       /* There's already a fake I/O around. */
+                       return -EBUSY;
+       }
+       if (cdev->private->state != DEV_STATE_ONLINE)
+               return -EIO;
+       /* Adjust requested path mask to exclude unusable paths. */
+       if (lpm) {
+               lpm &= sch->lpm;
+               if (lpm == 0)
+                       return -EACCES;
+       }
+       rc = cio_tm_start_key(sch, tcw, lpm, key);
+       if (rc == 0)
+               cdev->private->intparm = intparm;
+       return rc;
+}
+EXPORT_SYMBOL(ccw_device_tm_start_key);
+
+/**
+ * ccw_device_tm_start_timeout_key - perform start function
+ * @cdev: ccw device on which to perform the start function
+ * @tcw: transport-command word to be started
+ * @intparm: user defined parameter to be passed to the interrupt handler
+ * @lpm: mask of paths to use
+ * @key: storage key to use for storage access
+ * @expires: time span in jiffies after which to abort request
+ *
+ * Start the tcw on the given ccw device. Return zero on success, non-zero
+ * otherwise.
+ */
+int ccw_device_tm_start_timeout_key(struct ccw_device *cdev, struct tcw *tcw,
+                                   unsigned long intparm, u8 lpm, u8 key,
+                                   int expires)
+{
+       int ret;
+
+       ccw_device_set_timeout(cdev, expires);
+       ret = ccw_device_tm_start_key(cdev, tcw, intparm, lpm, key);
+       if (ret != 0)
+               ccw_device_set_timeout(cdev, 0);
+       return ret;
+}
+EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);
+
+/**
+ * ccw_device_tm_start - perform start function
+ * @cdev: ccw device on which to perform the start function
+ * @tcw: transport-command word to be started
+ * @intparm: user defined parameter to be passed to the interrupt handler
+ * @lpm: mask of paths to use
+ *
+ * Start the tcw on the given ccw device. Return zero on success, non-zero
+ * otherwise.
+ */
+int ccw_device_tm_start(struct ccw_device *cdev, struct tcw *tcw,
+                       unsigned long intparm, u8 lpm)
+{
+       return ccw_device_tm_start_key(cdev, tcw, intparm, lpm,
+                                      PAGE_DEFAULT_KEY);
+}
+EXPORT_SYMBOL(ccw_device_tm_start);
+
+/**
+ * ccw_device_tm_start_timeout - perform start function
+ * @cdev: ccw device on which to perform the start function
+ * @tcw: transport-command word to be started
+ * @intparm: user defined parameter to be passed to the interrupt handler
+ * @lpm: mask of paths to use
+ * @expires: time span in jiffies after which to abort request
+ *
+ * Start the tcw on the given ccw device. Return zero on success, non-zero
+ * otherwise.
+ */
+int ccw_device_tm_start_timeout(struct ccw_device *cdev, struct tcw *tcw,
+                              unsigned long intparm, u8 lpm, int expires)
+{
+       return ccw_device_tm_start_timeout_key(cdev, tcw, intparm, lpm,
+                                              PAGE_DEFAULT_KEY, expires);
+}
+EXPORT_SYMBOL(ccw_device_tm_start_timeout);
+
+/**
+ * ccw_device_get_mdc - accumulate max data count
+ * @cdev: ccw device for which the max data count is accumulated
+ * @mask: mask of paths to use
+ *
+ * Return the number of 64K-bytes blocks all paths at least support
+ * for a transport command. Return values <= 0 indicate failures.
+ */
+int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+       struct channel_path *chp;
+       struct chp_id chpid;
+       int mdc = 0, i;
+
+       /* Adjust requested path mask to excluded varied off paths. */
+       if (mask)
+               mask &= sch->lpm;
+       else
+               mask = sch->lpm;
+
+       chp_id_init(&chpid);
+       for (i = 0; i < 8; i++) {
+               if (!(mask & (0x80 >> i)))
+                       continue;
+               chpid.id = sch->schib.pmcw.chpid[i];
+               chp = chpid_to_chp(chpid);
+               if (!chp)
+                       continue;
+
+               mutex_lock(&chp->lock);
+               if (!chp->desc_fmt1.f) {
+                       mutex_unlock(&chp->lock);
+                       return 0;
+               }
+               if (!chp->desc_fmt1.r)
+                       mdc = 1;
+               mdc = mdc ? min_t(int, mdc, chp->desc_fmt1.mdc) :
+                           chp->desc_fmt1.mdc;
+               mutex_unlock(&chp->lock);
+       }
+
+       return mdc;
+}
+EXPORT_SYMBOL(ccw_device_get_mdc);
+
+/**
+ * ccw_device_tm_intrg - perform interrogate function
+ * @cdev: ccw device on which to perform the interrogate function
+ *
+ * Perform an interrogate function on the given ccw device. Return zero on
+ * success, non-zero otherwise.
+ */
+int ccw_device_tm_intrg(struct ccw_device *cdev)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+       if (!sch->schib.pmcw.ena)
+               return -EINVAL;
+       if (cdev->private->state != DEV_STATE_ONLINE)
+               return -EIO;
+       if (!scsw_is_tm(&sch->schib.scsw) ||
+           !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_START_PEND))
+               return -EINVAL;
+       return cio_tm_intrg(sch);
+}
+EXPORT_SYMBOL(ccw_device_tm_intrg);
+
+/**
+ * ccw_device_get_schid - obtain a subchannel id
+ * @cdev: device to obtain the id for
+ * @schid: where to fill in the values
+ */
+void ccw_device_get_schid(struct ccw_device *cdev, struct subchannel_id *schid)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+       *schid = sch->schid;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_schid);
+
+MODULE_LICENSE("GPL");
+EXPORT_SYMBOL(ccw_device_set_options_mask);
+EXPORT_SYMBOL(ccw_device_set_options);
+EXPORT_SYMBOL(ccw_device_clear_options);
+EXPORT_SYMBOL(ccw_device_clear);
+EXPORT_SYMBOL(ccw_device_halt);
+EXPORT_SYMBOL(ccw_device_resume);
+EXPORT_SYMBOL(ccw_device_start_timeout);
+EXPORT_SYMBOL(ccw_device_start);
+EXPORT_SYMBOL(ccw_device_start_timeout_key);
+EXPORT_SYMBOL(ccw_device_start_key);
+EXPORT_SYMBOL(ccw_device_get_ciw);
+EXPORT_SYMBOL(ccw_device_get_path_mask);
+EXPORT_SYMBOL_GPL(ccw_device_get_chp_desc);