Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 861 insertions, 0 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
new file mode 100644
index 000000000..c533d1dad
--- /dev/null
+++ b/drivers/s390/cio/device_ops.c
@@ -0,0 +1,861 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * Copyright IBM Corp. 2002, 2009
+ *
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *	      Cornelia Huck (cornelia.huck@de.ibm.com)
+ */
+#include <linux/export.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 to be returned upon conclusion of csch
+ *
+ * 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_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).
+ * The interruption handler will echo back the @intparm specified here, unless
+ * another interruption parameter is specified by a subsequent invocation of
+ * ccw_device_halt() or ccw_device_clear().
+ * 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)
+{
+	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;
+		if (expires)
+			ccw_device_set_timeout(cdev, expires);
+		break;
+	case -EACCES:
+	case -ENODEV:
+		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+		break;
+	}
+	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).
+ * The interruption handler will echo back the @intparm specified here, unless
+ * another interruption parameter is specified by a subsequent invocation of
+ * ccw_device_halt() or ccw_device_clear().
+ * 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)
+{
+	return ccw_device_start_timeout_key(cdev, cpa, intparm, lpm, key,
+					    flags, 0);
+}
+
+/**
+ * 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).
+ * The interruption handler will echo back the @intparm specified here, unless
+ * another interruption parameter is specified by a subsequent invocation of
+ * ccw_device_halt() or ccw_device_clear().
+ * 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).
+ * The interruption handler will echo back the @intparm specified here, unless
+ * another interruption parameter is specified by a subsequent invocation of
+ * ccw_device_halt() or ccw_device_clear().
+ * 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 to be returned upon conclusion of hsch
+ *
+ * ccw_device_halt() calls hsch on @cdev's subchannel.
+ * The interruption handler will echo back the @intparm specified here, unless
+ * another interruption parameter is specified by a subsequent invocation of
+ * ccw_device_clear().
+ * 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);
+}
+
+/**
+ * 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->dma_area->senseid.ciw[ciw_cnt].ct == ct)
+			return cdev->private->dma_area->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;
+}
+
+/**
+ * ccw_device_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_fmt0 *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_util_str() - return newly allocated utility strings
+ * @cdev: device to obtain the utility strings for
+ * @chp_idx: index of the channel path
+ *
+ * On success return a newly allocated copy of the utility strings
+ * associated with the given channel path. Return %NULL on error.
+ */
+u8 *ccw_device_get_util_str(struct ccw_device *cdev, int chp_idx)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct channel_path *chp;
+	struct chp_id chpid;
+	u8 *util_str;
+
+	chp_id_init(&chpid);
+	chpid.id = sch->schib.pmcw.chpid[chp_idx];
+	chp = chpid_to_chp(chpid);
+
+	util_str = kmalloc(sizeof(chp->desc_fmt3.util_str), GFP_KERNEL);
+	if (!util_str)
+		return NULL;
+
+	mutex_lock(&chp->lock);
+	memcpy(util_str, chp->desc_fmt3.util_str, sizeof(chp->desc_fmt3.util_str));
+	mutex_unlock(&chp->lock);
+
+	return util_str;
+}
+
+/**
+ * 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_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)
+{
+	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;
+		if (expires)
+			ccw_device_set_timeout(cdev, expires);
+	}
+	return rc;
+}
+EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);
+
+/**
+ * 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)
+{
+	return ccw_device_tm_start_timeout_key(cdev, tcw, intparm, lpm, key, 0);
+}
+EXPORT_SYMBOL(ccw_device_tm_start_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 value 0 indicates failure.
+ */
+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);
+
+/**
+ * ccw_device_pnso() - Perform Network-Subchannel Operation
+ * @cdev:		device on which PNSO is performed
+ * @pnso_area:		request and response block for the operation
+ * @oc:			Operation Code
+ * @resume_token:	resume token for multiblock response
+ * @cnc:		Boolean change-notification control
+ *
+ * pnso_area must be allocated by the caller with get_zeroed_page(GFP_KERNEL)
+ *
+ * Returns 0 on success.
+ */
+int ccw_device_pnso(struct ccw_device *cdev,
+		    struct chsc_pnso_area *pnso_area, u8 oc,
+		    struct chsc_pnso_resume_token resume_token, int cnc)
+{
+	struct subchannel_id schid;
+
+	ccw_device_get_schid(cdev, &schid);
+	return chsc_pnso(schid, pnso_area, oc, resume_token, cnc);
+}
+EXPORT_SYMBOL_GPL(ccw_device_pnso);
+
+/**
+ * ccw_device_get_cssid() - obtain Channel Subsystem ID
+ * @cdev: device to obtain the CSSID for
+ * @cssid: The resulting Channel Subsystem ID
+ */
+int ccw_device_get_cssid(struct ccw_device *cdev, u8 *cssid)
+{
+	struct device *sch_dev = cdev->dev.parent;
+	struct channel_subsystem *css = to_css(sch_dev->parent);
+
+	if (css->id_valid)
+		*cssid = css->cssid;
+	return css->id_valid ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_cssid);
+
+/**
+ * ccw_device_get_iid() - obtain MIF-image ID
+ * @cdev: device to obtain the MIF-image ID for
+ * @iid: The resulting MIF-image ID
+ */
+int ccw_device_get_iid(struct ccw_device *cdev, u8 *iid)
+{
+	struct device *sch_dev = cdev->dev.parent;
+	struct channel_subsystem *css = to_css(sch_dev->parent);
+
+	if (css->id_valid)
+		*iid = css->iid;
+	return css->id_valid ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_iid);
+
+/**
+ * ccw_device_get_chpid() - obtain Channel Path ID
+ * @cdev: device to obtain the Channel Path ID for
+ * @chp_idx: Index of the channel path
+ * @chpid: The resulting Channel Path ID
+ */
+int ccw_device_get_chpid(struct ccw_device *cdev, int chp_idx, u8 *chpid)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	int mask;
+
+	if ((chp_idx < 0) || (chp_idx > 7))
+		return -EINVAL;
+	mask = 0x80 >> chp_idx;
+	if (!(sch->schib.pmcw.pim & mask))
+		return -ENODEV;
+
+	*chpid = sch->schib.pmcw.chpid[chp_idx];
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_chpid);
+
+/**
+ * ccw_device_get_chid() - obtain Channel ID associated with specified CHPID
+ * @cdev: device to obtain the Channel ID for
+ * @chp_idx: Index of the channel path
+ * @chid: The resulting Channel ID
+ */
+int ccw_device_get_chid(struct ccw_device *cdev, int chp_idx, u16 *chid)
+{
+	struct chp_id cssid_chpid;
+	struct channel_path *chp;
+	int rc;
+
+	chp_id_init(&cssid_chpid);
+	rc = ccw_device_get_chpid(cdev, chp_idx, &cssid_chpid.id);
+	if (rc)
+		return rc;
+	chp = chpid_to_chp(cssid_chpid);
+	if (!chp)
+		return -ENODEV;
+
+	mutex_lock(&chp->lock);
+	if (chp->desc_fmt1.flags & 0x10)
+		*chid = chp->desc_fmt1.chid;
+	else
+		rc = -ENODEV;
+	mutex_unlock(&chp->lock);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_chid);
+
+/*
+ * Allocate zeroed dma coherent 31 bit addressable memory using
+ * the subchannels dma pool. Maximal size of allocation supported
+ * is PAGE_SIZE.
+ */
+void *ccw_device_dma_zalloc(struct ccw_device *cdev, size_t size)
+{
+	void *addr;
+
+	if (!get_device(&cdev->dev))
+		return NULL;
+	addr = cio_gp_dma_zalloc(cdev->private->dma_pool, &cdev->dev, size);
+	if (IS_ERR_OR_NULL(addr))
+		put_device(&cdev->dev);
+	return addr;
+}
+EXPORT_SYMBOL(ccw_device_dma_zalloc);
+
+void ccw_device_dma_free(struct ccw_device *cdev, void *cpu_addr, size_t size)
+{
+	if (!cpu_addr)
+		return;
+	cio_gp_dma_free(cdev->private->dma_pool, cpu_addr, size);
+	put_device(&cdev->dev);
+}
+EXPORT_SYMBOL(ccw_device_dma_free);
+
+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);
+EXPORT_SYMBOL_GPL(ccw_device_get_util_str);