[S390] cio: use ccw request infrastructure for sense id
authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Mon, 7 Dec 2009 11:51:26 +0000 (12:51 +0100)
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>
Mon, 7 Dec 2009 11:51:31 +0000 (12:51 +0100)
Use the newly introduced ccw request infrastructure to implement
the sense id operation.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/cio/device.h
drivers/s390/cio/device_fsm.c
drivers/s390/cio/device_id.c

index f3c8a2a8c3a4ec860963ae0549e02b1e2a53a01c..2815798c416563c56d1e0bfc163dcaed4ca55b7b 100644 (file)
@@ -108,7 +108,6 @@ void ccw_request_notoper(struct ccw_device *cdev);
 
 /* Function prototypes for sense id stuff. */
 void ccw_device_sense_id_start(struct ccw_device *);
-void ccw_device_sense_id_irq(struct ccw_device *, enum dev_event);
 void ccw_device_sense_id_done(struct ccw_device *, int);
 
 /* Function prototypes for path grouping stuff. */
index c397442ab3d8273a1d3b4c035e0679e9aa9b9927..6247d07d395e1ea6888ea7137145b66f9794b3f2 100644 (file)
@@ -229,7 +229,6 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
 
        sch = to_subchannel(cdev->dev.parent);
 
-       ccw_device_set_timeout(cdev, 0);
        cio_disable_subchannel(sch);
        /*
         * Now that we tried recognition, we have performed device selection
@@ -263,22 +262,10 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
        }
        switch (state) {
        case DEV_STATE_NOT_OPER:
-               CIO_MSG_EVENT(2, "SenseID : unknown device %04x on "
-                             "subchannel 0.%x.%04x\n",
-                             cdev->private->dev_id.devno,
-                             sch->schid.ssid, sch->schid.sch_no);
                break;
        case DEV_STATE_OFFLINE:
                if (!cdev->online) {
                        ccw_device_update_sense_data(cdev);
-                       /* Issue device info message. */
-                       CIO_MSG_EVENT(4, "SenseID : device 0.%x.%04x reports: "
-                                     "CU  Type/Mod = %04X/%02X, Dev Type/Mod "
-                                     "= %04X/%02X\n",
-                                     cdev->private->dev_id.ssid,
-                                     cdev->private->dev_id.devno,
-                                     cdev->id.cu_type, cdev->id.cu_model,
-                                     cdev->id.dev_type, cdev->id.dev_model);
                        break;
                }
                cdev->private->state = DEV_STATE_OFFLINE;
@@ -293,10 +280,6 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
                }
                return;
        case DEV_STATE_BOXED:
-               CIO_MSG_EVENT(0, "SenseID : boxed device %04x on "
-                             " subchannel 0.%x.%04x\n",
-                             cdev->private->dev_id.devno,
-                             sch->schid.ssid, sch->schid.sch_no);
                if (cdev->id.cu_type != 0) { /* device was recognized before */
                        cdev->private->flags.recog_done = 1;
                        cdev->private->state = DEV_STATE_BOXED;
@@ -520,27 +503,25 @@ void ccw_device_recognition(struct ccw_device *cdev)
 }
 
 /*
- * Handle timeout in device recognition.
+ * Handle events for states that use the ccw request infrastructure.
  */
-static void
-ccw_device_recog_timeout(struct ccw_device *cdev, enum dev_event dev_event)
+static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
 {
-       int ret;
-
-       ret = ccw_device_cancel_halt_clear(cdev);
-       switch (ret) {
-       case 0:
-               ccw_device_recog_done(cdev, DEV_STATE_BOXED);
+       switch (e) {
+       case DEV_EVENT_NOTOPER:
+               ccw_request_notoper(cdev);
                break;
-       case -ENODEV:
-               ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
+       case DEV_EVENT_INTERRUPT:
+               ccw_request_handler(cdev);
+               break;
+       case DEV_EVENT_TIMEOUT:
+               ccw_request_timeout(cdev);
                break;
        default:
-               ccw_device_set_timeout(cdev, 3*HZ);
+               break;
        }
 }
 
-
 void
 ccw_device_verify_done(struct ccw_device *cdev, int err)
 {
@@ -712,15 +693,6 @@ ccw_device_onoff_timeout(struct ccw_device *cdev, enum dev_event dev_event)
        }
 }
 
-/*
- * Handle not oper event in device recognition.
- */
-static void
-ccw_device_recog_notoper(struct ccw_device *cdev, enum dev_event dev_event)
-{
-       ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
-}
-
 /*
  * Handle not operational event in non-special state.
  */
@@ -1015,10 +987,6 @@ ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
        if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
                /* Couldn't enable the subchannel for i/o. Sick device. */
                return;
-
-       /* After 60s the device recognition is considered to have failed. */
-       ccw_device_set_timeout(cdev, 60*HZ);
-
        cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
        ccw_device_sense_id_start(cdev);
 }
@@ -1141,9 +1109,9 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                [DEV_EVENT_VERIFY]      = ccw_device_nop,
        },
        [DEV_STATE_SENSE_ID] = {
-               [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
-               [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
-               [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
+               [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
+               [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
+               [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
                [DEV_EVENT_VERIFY]      = ccw_device_nop,
        },
        [DEV_STATE_OFFLINE] = {
@@ -1209,9 +1177,9 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                [DEV_EVENT_VERIFY]      = ccw_device_start_id,
        },
        [DEV_STATE_DISCONNECTED_SENSE_ID] = {
-               [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
-               [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
-               [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
+               [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
+               [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
+               [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
                [DEV_EVENT_VERIFY]      = ccw_device_nop,
        },
        [DEV_STATE_CMFCHANGE] = {
index 1bdaa614e34fef0dbebe6d6f5f03aa7de7ed25a9..4728644ed85c5c72521ca761276de3a326ff73b6 100644 (file)
@@ -1,40 +1,39 @@
 /*
- * drivers/s390/cio/device_id.c
+ *  CCW device SENSE ID I/O handling.
  *
- *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- *                      IBM Corporation
- *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
- *              Martin Schwidefsky (schwidefsky@de.ibm.com)
- *
- * Sense ID functions.
+ *    Copyright IBM Corp. 2002,2009
+ *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ *              Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *              Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
  */
 
-#include <linux/module.h>
-#include <linux/init.h>
 #include <linux/kernel.h>
-
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/errno.h>
 #include <asm/ccwdev.h>
-#include <asm/delay.h>
+#include <asm/setup.h>
 #include <asm/cio.h>
-#include <asm/lowcore.h>
 #include <asm/diag.h>
 
 #include "cio.h"
 #include "cio_debug.h"
-#include "css.h"
 #include "device.h"
-#include "ioasm.h"
 #include "io_sch.h"
 
+#define SENSE_ID_RETRIES       5
+#define SENSE_ID_TIMEOUT       (10 * HZ)
+#define SENSE_ID_MIN_LEN       4
+#define SENSE_ID_BASIC_LEN     7
+
 /**
- * vm_vdev_to_cu_type - Convert vm virtual device into control unit type
- *                     for certain devices.
- * @class: virtual device class
- * @type: virtual device type
+ * diag210_to_senseid - convert diag 0x210 data to sense id information
+ * @senseid: sense id
+ * @diag: diag 0x210 data
  *
- * Returns control unit type if a match was made or %0xffff otherwise.
+ * Return 0 on success, non-zero otherwise.
  */
-static int vm_vdev_to_cu_type(int class, int type)
+static int diag210_to_senseid(struct senseid *senseid, struct diag210 *diag)
 {
        static struct {
                int class, type, cu_type;
@@ -71,253 +70,153 @@ static int vm_vdev_to_cu_type(int class, int type)
        };
        int i;
 
-       for (i = 0; i < ARRAY_SIZE(vm_devices); i++)
-               if (class == vm_devices[i].class && type == vm_devices[i].type)
-                       return vm_devices[i].cu_type;
+       /* Special case for osa devices. */
+       if (diag->vrdcvcla == 0x02 && diag->vrdcvtyp == 0x20) {
+               senseid->cu_type = 0x3088;
+               senseid->cu_model = 0x60;
+               senseid->reserved = 0xff;
+               return 0;
+       }
+       for (i = 0; i < ARRAY_SIZE(vm_devices); i++) {
+               if (diag->vrdcvcla == vm_devices[i].class &&
+                   diag->vrdcvtyp == vm_devices[i].type) {
+                       senseid->cu_type = vm_devices[i].cu_type;
+                       senseid->reserved = 0xff;
+                       return 0;
+               }
+       }
 
-       return 0xffff;
+       return -ENODEV;
 }
 
 /**
- * diag_get_dev_info - retrieve device information via DIAG X'210'
- * @devno: device number
- * @ps: pointer to sense ID data area
+ * diag_get_dev_info - retrieve device information via diag 0x210
+ * @cdev: ccw device
  *
  * Returns zero on success, non-zero otherwise.
  */
-static int diag_get_dev_info(u16 devno, struct senseid *ps)
+static int diag210_get_dev_info(struct ccw_device *cdev)
 {
+       struct ccw_dev_id *dev_id = &cdev->private->dev_id;
+       struct senseid *senseid = &cdev->private->senseid;
        struct diag210 diag_data;
-       int ccode;
-
-       CIO_TRACE_EVENT (4, "VMvdinf");
-
-       diag_data = (struct diag210) {
-               .vrdcdvno = devno,
-               .vrdclen = sizeof (diag_data),
-       };
-
-       ccode = diag210 (&diag_data);
-       if ((ccode == 0) || (ccode == 2)) {
-               ps->reserved = 0xff;
-
-               /* Special case for osa devices. */
-               if (diag_data.vrdcvcla == 0x02 && diag_data.vrdcvtyp == 0x20) {
-                       ps->cu_type = 0x3088;
-                       ps->cu_model = 0x60;
-                       return 0;
-               }
-               ps->cu_type = vm_vdev_to_cu_type(diag_data.vrdcvcla,
-                                               diag_data.vrdcvtyp);
-               if (ps->cu_type != 0xffff)
-                       return 0;
-       }
-
-       CIO_MSG_EVENT(0, "DIAG X'210' for device %04X returned (cc = %d):"
-                     "vdev class : %02X, vdev type : %04X \n ...  "
-                     "rdev class : %02X, rdev type : %04X, "
-                     "rdev model: %02X\n",
-                     devno, ccode,
-                     diag_data.vrdcvcla, diag_data.vrdcvtyp,
-                     diag_data.vrdcrccl, diag_data.vrdccrty,
-                     diag_data.vrdccrmd);
-
+       int rc;
+
+       if (dev_id->ssid != 0)
+               return -ENODEV;
+       memset(&diag_data, 0, sizeof(diag_data));
+       diag_data.vrdcdvno      = dev_id->devno;
+       diag_data.vrdclen       = sizeof(diag_data);
+       rc = diag210(&diag_data);
+       CIO_TRACE_EVENT(4, "diag210");
+       CIO_HEX_EVENT(4, &rc, sizeof(rc));
+       CIO_HEX_EVENT(4, &diag_data, sizeof(diag_data));
+       if (rc != 0 && rc != 2)
+               goto err_failed;
+       if (diag210_to_senseid(senseid, &diag_data))
+               goto err_unknown;
+       return 0;
+
+err_unknown:
+       CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: unknown diag210 data\n",
+                     dev_id->ssid, dev_id->devno);
+       return -ENODEV;
+err_failed:
+       CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: diag210 failed (rc=%d)\n",
+                     dev_id->ssid, dev_id->devno, rc);
        return -ENODEV;
 }
 
 /*
- * Start Sense ID helper function.
- * Try to obtain the 'control unit'/'device type' information
- *  associated with the subchannel.
+ * Initialize SENSE ID data.
  */
-static int
-__ccw_device_sense_id_start(struct ccw_device *cdev)
-{
-       struct subchannel *sch;
-       struct ccw1 *ccw;
-       int ret;
-
-       sch = to_subchannel(cdev->dev.parent);
-       /* Setup sense channel program. */
-       ccw = cdev->private->iccws;
-       ccw->cmd_code = CCW_CMD_SENSE_ID;
-       ccw->cda = (__u32) __pa (&cdev->private->senseid);
-       ccw->count = sizeof (struct senseid);
-       ccw->flags = CCW_FLAG_SLI;
-
-       /* Reset device status. */
-       memset(&cdev->private->irb, 0, sizeof(struct irb));
-
-       /* Try on every path. */
-       ret = -ENODEV;
-       while (cdev->private->imask != 0) {
-               cdev->private->senseid.cu_type = 0xFFFF;
-               if ((sch->opm & cdev->private->imask) != 0 &&
-                   cdev->private->iretry > 0) {
-                       cdev->private->iretry--;
-                       /* Reset internal retry indication. */
-                       cdev->private->flags.intretry = 0;
-                       ret = cio_start (sch, cdev->private->iccws,
-                                        cdev->private->imask);
-                       /* ret is 0, -EBUSY, -EACCES or -ENODEV */
-                       if (ret != -EACCES)
-                               return ret;
-               }
-               cdev->private->imask >>= 1;
-               cdev->private->iretry = 5;
-       }
-       return ret;
-}
-
-void
-ccw_device_sense_id_start(struct ccw_device *cdev)
+static void snsid_init(struct ccw_device *cdev)
 {
-       int ret;
-
-       memset (&cdev->private->senseid, 0, sizeof (struct senseid));
-       cdev->private->imask = 0x80;
-       cdev->private->iretry = 5;
-       ret = __ccw_device_sense_id_start(cdev);
-       if (ret && ret != -EBUSY)
-               ccw_device_sense_id_done(cdev, ret);
+       cdev->private->flags.esid = 0;
+       memset(&cdev->private->senseid, 0, sizeof(cdev->private->senseid));
+       cdev->private->senseid.cu_type = 0xffff;
 }
 
 /*
- * Called from interrupt context to check if a valid answer
- * to Sense ID was received.
+ * Check for complete SENSE ID data.
  */
-static int
-ccw_device_check_sense_id(struct ccw_device *cdev)
+static int snsid_check(struct ccw_device *cdev, void *data)
 {
-       struct subchannel *sch;
-       struct irb *irb;
-
-       sch = to_subchannel(cdev->dev.parent);
-       irb = &cdev->private->irb;
-
-       /* Check the error cases. */
-       if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
-               /* Retry Sense ID if requested. */
-               if (cdev->private->flags.intretry) {
-                       cdev->private->flags.intretry = 0;
-                       return -EAGAIN;
-               }
-               return -ETIME;
-       }
-       if (irb->esw.esw0.erw.cons && (irb->ecw[0] & SNS0_CMD_REJECT)) {
-               /*
-                * if the device doesn't support the SenseID
-                *  command further retries wouldn't help ...
-                * NB: We don't check here for intervention required like we
-                *     did before, because tape devices with no tape inserted
-                *     may present this status *in conjunction with* the
-                *     sense id information. So, for intervention required,
-                *     we use the "whack it until it talks" strategy...
-                */
-               CIO_MSG_EVENT(0, "SenseID : device %04x on Subchannel "
-                             "0.%x.%04x reports cmd reject\n",
-                             cdev->private->dev_id.devno, sch->schid.ssid,
-                             sch->schid.sch_no);
+       struct cmd_scsw *scsw = &cdev->private->irb.scsw.cmd;
+       int len = sizeof(struct senseid) - scsw->count;
+
+       /* Check for incomplete SENSE ID data. */
+       if (len < SENSE_ID_MIN_LEN)
+               goto out_restart;
+       if (cdev->private->senseid.cu_type == 0xffff)
+               goto out_restart;
+       /* Check for incompatible SENSE ID data. */
+       if (cdev->private->senseid.reserved != 0xff)
                return -EOPNOTSUPP;
-       }
-       if (irb->esw.esw0.erw.cons) {
-               CIO_MSG_EVENT(2, "SenseID : UC on dev 0.%x.%04x, "
-                             "lpum %02X, cnt %02d, sns :"
-                             " %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
-                             cdev->private->dev_id.ssid,
-                             cdev->private->dev_id.devno,
-                             irb->esw.esw0.sublog.lpum,
-                             irb->esw.esw0.erw.scnt,
-                             irb->ecw[0], irb->ecw[1],
-                             irb->ecw[2], irb->ecw[3],
-                             irb->ecw[4], irb->ecw[5],
-                             irb->ecw[6], irb->ecw[7]);
-               return -EAGAIN;
-       }
-       if (irb->scsw.cmd.cc == 3) {
-               u8 lpm;
+       /* Check for extended-identification information. */
+       if (len > SENSE_ID_BASIC_LEN)
+               cdev->private->flags.esid = 1;
+       return 0;
 
-               lpm = to_io_private(sch)->orb.cmd.lpm;
-               if ((lpm & sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
-                       CIO_MSG_EVENT(4, "SenseID : path %02X for device %04x "
-                                     "on subchannel 0.%x.%04x is "
-                                     "'not operational'\n", lpm,
-                                     cdev->private->dev_id.devno,
-                                     sch->schid.ssid, sch->schid.sch_no);
-               return -EACCES;
-       }
-
-       /* Did we get a proper answer ? */
-       if (irb->scsw.cmd.cc == 0 && cdev->private->senseid.cu_type != 0xFFFF &&
-           cdev->private->senseid.reserved == 0xFF) {
-               if (irb->scsw.cmd.count < sizeof(struct senseid) - 8)
-                       cdev->private->flags.esid = 1;
-               return 0; /* Success */
-       }
-
-       /* Hmm, whatever happened, try again. */
-       CIO_MSG_EVENT(2, "SenseID : start_IO() for device %04x on "
-                     "subchannel 0.%x.%04x returns status %02X%02X\n",
-                     cdev->private->dev_id.devno, sch->schid.ssid,
-                     sch->schid.sch_no,
-                     irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
+out_restart:
+       snsid_init(cdev);
        return -EAGAIN;
 }
 
 /*
- * Got interrupt for Sense ID.
+ * Process SENSE ID request result.
  */
-void
-ccw_device_sense_id_irq(struct ccw_device *cdev, enum dev_event dev_event)
+static void snsid_callback(struct ccw_device *cdev, void *data, int rc)
 {
-       struct subchannel *sch;
-       struct irb *irb;
-       int ret;
-
-       sch = to_subchannel(cdev->dev.parent);
-       irb = (struct irb *) __LC_IRB;
-       /* Retry sense id, if needed. */
-       if (irb->scsw.cmd.stctl ==
-           (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-               if ((irb->scsw.cmd.cc == 1) || !irb->scsw.cmd.actl) {
-                       ret = __ccw_device_sense_id_start(cdev);
-                       if (ret && ret != -EBUSY)
-                               ccw_device_sense_id_done(cdev, ret);
+       struct ccw_dev_id *id = &cdev->private->dev_id;
+       struct senseid *senseid = &cdev->private->senseid;
+       int vm = 0;
+
+       if (rc && MACHINE_IS_VM) {
+               /* Try diag 0x210 fallback on z/VM. */
+               snsid_init(cdev);
+               if (diag210_get_dev_info(cdev) == 0) {
+                       rc = 0;
+                       vm = 1;
                }
-               return;
        }
-       if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
-               return;
-       ret = ccw_device_check_sense_id(cdev);
-       memset(&cdev->private->irb, 0, sizeof(struct irb));
-       switch (ret) {
-       /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN or -EACCES */
-       case 0:                 /* Sense id succeeded. */
-       case -ETIME:            /* Sense id stopped by timeout. */
-               ccw_device_sense_id_done(cdev, ret);
-               break;
-       case -EACCES:           /* channel is not operational. */
-               sch->lpm &= ~cdev->private->imask;
-               cdev->private->imask >>= 1;
-               cdev->private->iretry = 5;
-               /* fall through. */
-       case -EAGAIN:           /* try again. */
-               ret = __ccw_device_sense_id_start(cdev);
-               if (ret == 0 || ret == -EBUSY)
-                       break;
-               /* fall through. */
-       default:                /* Sense ID failed. Try asking VM. */
-               if (MACHINE_IS_VM)
-                       ret = diag_get_dev_info(cdev->private->dev_id.devno,
-                                               &cdev->private->senseid);
-               else
-                       /*
-                        * If we can't couldn't identify the device type we
-                        *  consider the device "not operational".
-                        */
-                       ret = -ENODEV;
+       CIO_MSG_EVENT(2, "snsid: device 0.%x.%04x: rc=%d %04x/%02x "
+                     "%04x/%02x%s\n", id->ssid, id->devno, rc,
+                     senseid->cu_type, senseid->cu_model, senseid->dev_type,
+                     senseid->dev_model, vm ? " (diag210)" : "");
+       ccw_device_sense_id_done(cdev, rc);
+}
 
-               ccw_device_sense_id_done(cdev, ret);
-               break;
-       }
+/**
+ * ccw_device_sense_id_start - perform SENSE ID
+ * @cdev: ccw device
+ *
+ * Execute a SENSE ID channel program on @cdev to update its sense id
+ * information. When finished, call ccw_device_sense_id_done with a
+ * return code specifying the result.
+ */
+void ccw_device_sense_id_start(struct ccw_device *cdev)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+       struct ccw_request *req = &cdev->private->req;
+       struct ccw1 *cp = cdev->private->iccws;
+
+       CIO_TRACE_EVENT(4, "snsid");
+       CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
+       /* Data setup. */
+       snsid_init(cdev);
+       /* Channel program setup. */
+       cp->cmd_code    = CCW_CMD_SENSE_ID;
+       cp->cda         = (u32) (addr_t) &cdev->private->senseid;
+       cp->count       = sizeof(struct senseid);
+       cp->flags       = CCW_FLAG_SLI;
+       /* Request setup. */
+       memset(req, 0, sizeof(*req));
+       req->cp         = cp;
+       req->timeout    = SENSE_ID_TIMEOUT;
+       req->maxretries = SENSE_ID_RETRIES;
+       req->lpm        = sch->schib.pmcw.pam & sch->opm;
+       req->check      = snsid_check;
+       req->callback   = snsid_callback;
+       ccw_request_start(cdev);
 }