1 files changed, 247 insertions, 167 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 4845d64f2842..61c07b4a0fe8 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -1,10 +1,11 @@
+// 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/module.h>
+#include <linux/export.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
@@ -97,7 +98,7 @@ void ccw_device_clear_options(struct ccw_device *cdev, unsigned long flags)
 }
 
 /**
- * ccw_device_is_pathgroup - determine if paths to this device are grouped
+ * 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.
@@ -109,7 +110,7 @@ int ccw_device_is_pathgroup(struct ccw_device *cdev)
 EXPORT_SYMBOL(ccw_device_is_pathgroup);
 
 /**
- * ccw_device_is_multipath - determine if device is operating in multipath mode
+ * 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.
@@ -123,9 +124,7 @@ 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
+ * @intparm: interruption parameter to be returned upon conclusion of csch
  *
  * ccw_device_clear() calls csch on @cdev's subchannel.
  * Returns:
@@ -158,7 +157,7 @@ int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
 }
 
 /**
- * ccw_device_start_key() - start a s390 channel program with key
+ * 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
@@ -169,10 +168,18 @@ int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
  * @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;
@@ -181,9 +188,9 @@ int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
  * 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)
+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;
@@ -195,11 +202,16 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 		return -EINVAL;
 	if (cdev->private->state == DEV_STATE_NOT_OPER)
 		return -ENODEV;
-	if (cdev->private->state == DEV_STATE_VERIFY) {
+	if (cdev->private->state == DEV_STATE_VERIFY ||
+	    cdev->private->flags.doverify) {
 		/* Remember to fake irb when finished. */
 		if (!cdev->private->flags.fake_irb) {
 			cdev->private->flags.fake_irb = FAKE_CMD_IRB;
 			cdev->private->intparm = intparm;
+			CIO_MSG_EVENT(2, "fakeirb: queue device 0.%x.%04x intparm %lx type=%d\n",
+				      cdev->private->dev_id.ssid,
+				      cdev->private->dev_id.devno, intparm,
+				      cdev->private->flags.fake_irb);
 			return 0;
 		} else
 			/* There's already a fake I/O around. */
@@ -207,8 +219,7 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 	}
 	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)
+	     !(sch->schib.scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS)))
 		return -EBUSY;
 	ret = cio_set_options (sch, flags);
 	if (ret)
@@ -223,6 +234,8 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 	switch (ret) {
 	case 0:
 		cdev->private->intparm = intparm;
+		if (expires)
+			ccw_device_set_timeout(cdev, expires);
 		break;
 	case -EACCES:
 	case -ENODEV:
@@ -233,7 +246,7 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 }
 
 /**
- * ccw_device_start_timeout_key() - start a s390 channel program with timeout and key
+ * 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
@@ -244,15 +257,13 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
  * @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;
@@ -261,19 +272,12 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
  * 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 ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
+			 unsigned long intparm, __u8 lpm, __u8 key,
+			 unsigned long flags)
 {
-	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;
+	return ccw_device_start_timeout_key(cdev, cpa, intparm, lpm, key,
+					    flags, 0);
 }
 
 /**
@@ -291,6 +295,9 @@ int ccw_device_start_timeout_key(struct ccw_device *cdev, struct ccw1 *cpa,
  * 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;
@@ -326,6 +333,9 @@ int ccw_device_start(struct ccw_device *cdev, struct ccw1 *cpa,
  * 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;
@@ -347,11 +357,12 @@ int ccw_device_start_timeout(struct ccw_device *cdev, struct ccw1 *cpa,
 /**
  * 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
+ * @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,
@@ -412,52 +423,6 @@ int ccw_device_resume(struct ccw_device *cdev)
 	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
@@ -479,8 +444,8 @@ struct ciw *ccw_device_get_ciw(struct ccw_device *cdev, __u32 ct)
 	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;
+		if (cdev->private->dma_area->senseid.ciw[ciw_cnt].ct == ct)
+			return &cdev->private->dma_area->senseid.ciw[ciw_cnt];
 	return NULL;
 }
 
@@ -502,80 +467,58 @@ __u8 ccw_device_get_path_mask(struct ccw_device *cdev)
 	return sch->lpm;
 }
 
-struct stlck_data {
-	struct completion done;
-	int rc;
-};
-
-void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc)
+/**
+ * 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 stlck_data *sdata = data;
+	struct subchannel *sch;
+	struct chp_id chpid;
 
-	sdata->rc = rc;
-	complete(&sdata->done);
+	sch = to_subchannel(cdev->dev.parent);
+	chp_id_init(&chpid);
+	chpid.id = sch->schib.pmcw.chpid[chp_idx];
+	return chp_get_chp_desc(chpid);
 }
 
-/*
- * Perform unconditional reserve + release.
+/**
+ * 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.
  */
-int ccw_device_stlck(struct ccw_device *cdev)
+u8 *ccw_device_get_util_str(struct ccw_device *cdev, int chp_idx)
 {
 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
-	struct stlck_data data;
-	u8 *buffer;
-	int rc;
+	struct channel_path *chp;
+	struct chp_id chpid;
+	u8 *util_str;
 
-	/* 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);
+	chp_id_init(&chpid);
+	chpid.id = sch->schib.pmcw.chpid[chp_idx];
+	chp = chpid_to_chp(chpid);
 
-	return rc;
-}
+	util_str = kmalloc(sizeof(chp->desc_fmt3.util_str), GFP_KERNEL);
+	if (!util_str)
+		return NULL;
 
-void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no)
-{
-	struct subchannel *sch;
-	struct chp_id chpid;
+	mutex_lock(&chp->lock);
+	memcpy(util_str, chp->desc_fmt3.util_str, sizeof(chp->desc_fmt3.util_str));
+	mutex_unlock(&chp->lock);
 
-	sch = to_subchannel(cdev->dev.parent);
-	chp_id_init(&chpid);
-	chpid.id = sch->schib.pmcw.chpid[chp_no];
-	return chp_get_chp_desc(chpid);
+	return util_str;
 }
 
 /**
- * ccw_device_get_id - obtain a ccw device id
+ * ccw_device_get_id() - obtain a ccw device id
  * @cdev: device to obtain the id for
  * @dev_id: where to fill in the values
  */
@@ -586,18 +529,20 @@ void ccw_device_get_id(struct ccw_device *cdev, struct ccw_dev_id *dev_id)
 EXPORT_SYMBOL(ccw_device_get_id);
 
 /**
- * ccw_device_tm_start_key - perform start function
+ * 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_key(struct ccw_device *cdev, struct tcw *tcw,
-			    unsigned long intparm, u8 lpm, u8 key)
+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;
@@ -610,6 +555,10 @@ int ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
 		if (!cdev->private->flags.fake_irb) {
 			cdev->private->flags.fake_irb = FAKE_TM_IRB;
 			cdev->private->intparm = intparm;
+			CIO_MSG_EVENT(2, "fakeirb: queue device 0.%x.%04x intparm %lx type=%d\n",
+				      cdev->private->dev_id.ssid,
+				      cdev->private->dev_id.devno, intparm,
+				      cdev->private->flags.fake_irb);
 			return 0;
 		} else
 			/* There's already a fake I/O around. */
@@ -624,40 +573,35 @@ int ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
 			return -EACCES;
 	}
 	rc = cio_tm_start_key(sch, tcw, lpm, key);
-	if (rc == 0)
+	if (rc == 0) {
 		cdev->private->intparm = intparm;
+		if (expires)
+			ccw_device_set_timeout(cdev, expires);
+	}
 	return rc;
 }
-EXPORT_SYMBOL(ccw_device_tm_start_key);
+EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);
 
 /**
- * ccw_device_tm_start_timeout_key - perform start function
+ * 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
- * @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 ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
+			    unsigned long intparm, u8 lpm, u8 key)
 {
-	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;
+	return ccw_device_tm_start_timeout_key(cdev, tcw, intparm, lpm, key, 0);
 }
-EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);
+EXPORT_SYMBOL(ccw_device_tm_start_key);
 
 /**
- * ccw_device_tm_start - perform start function
+ * 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
@@ -675,7 +619,7 @@ int ccw_device_tm_start(struct ccw_device *cdev, struct tcw *tcw,
 EXPORT_SYMBOL(ccw_device_tm_start);
 
 /**
- * ccw_device_tm_start_timeout - perform start function
+ * 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
@@ -694,12 +638,12 @@ int ccw_device_tm_start_timeout(struct ccw_device *cdev, struct tcw *tcw,
 EXPORT_SYMBOL(ccw_device_tm_start_timeout);
 
 /**
- * ccw_device_get_mdc - accumulate max data count
+ * 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.
+ * for a transport command. Return value 0 indicates failure.
  */
 int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 {
@@ -740,7 +684,7 @@ int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 EXPORT_SYMBOL(ccw_device_get_mdc);
 
 /**
- * ccw_device_tm_intrg - perform interrogate function
+ * 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
@@ -762,7 +706,7 @@ int ccw_device_tm_intrg(struct ccw_device *cdev)
 EXPORT_SYMBOL(ccw_device_tm_intrg);
 
 /**
- * ccw_device_get_schid - obtain a subchannel id
+ * ccw_device_get_schid() - obtain a subchannel id
  * @cdev: device to obtain the id for
  * @schid: where to fill in the values
  */
@@ -774,7 +718,142 @@ void ccw_device_get_schid(struct ccw_device *cdev, struct subchannel_id *schid)
 }
 EXPORT_SYMBOL_GPL(ccw_device_get_schid);
 
-MODULE_LICENSE("GPL");
+/**
+ * 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,
+			    dma32_t *dma_handle)
+{
+	void *addr;
+
+	if (!get_device(&cdev->dev))
+		return NULL;
+	addr = __cio_gp_dma_zalloc(cdev->private->dma_pool, &cdev->dev, size, dma_handle);
+	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);
@@ -788,3 +867,4 @@ 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);