drivers/s390/cio/device_id.c - maze/linux - Git at Google

 /*
  * drivers/s390/cio/device_id.c
  *
  *    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.
  */

 #include <linux/module.h>
 #include <linux/config.h>
 #include <linux/init.h>

 #include <asm/ccwdev.h>
 #include <asm/delay.h>
 #include <asm/cio.h>
 #include <asm/lowcore.h>

 #include "cio.h"
 #include "cio_debug.h"
 #include "css.h"
 #include "device.h"
 #include "ioasm.h"

 /*
  * diag210 is used under VM to get information about a virtual device
  */
 #ifdef CONFIG_64BIT
 int
 diag210(struct diag210 * addr)
 {
 	/*
 	 * diag 210 needs its data below the 2GB border, so we
 	 * use a static data area to be sure
 	 */
 	static struct diag210 diag210_tmp;
 	static DEFINE_SPINLOCK(diag210_lock);
 	unsigned long flags;
 	int ccode;

 	spin_lock_irqsave(&diag210_lock, flags);
 	diag210_tmp = *addr;

 	asm volatile (
 		"   lhi	  %0,-1\n"
 		"   sam31\n"
 		"   diag  %1,0,0x210\n"
 		"0: ipm	  %0\n"
 		"   srl	  %0,28\n"
 		"1: sam64\n"
 		".section __ex_table,\"a\"\n"
 		"    .align 8\n"
 		"    .quad 0b,1b\n"
 		".previous"
 		: "=&d" (ccode) : "a" (__pa(&diag210_tmp)) : "cc", "memory" );

 	*addr = diag210_tmp;
 	spin_unlock_irqrestore(&diag210_lock, flags);

 	return ccode;
 }
 #else
 int
 diag210(struct diag210 * addr)
 {
 	int ccode;

 	asm volatile (
 		"   lhi	  %0,-1\n"
 		"   diag  %1,0,0x210\n"
 		"0: ipm	  %0\n"
 		"   srl	  %0,28\n"
 		"1:\n"
 		".section __ex_table,\"a\"\n"
 		"    .align 4\n"
 		"    .long 0b,1b\n"
 		".previous"
 		: "=&d" (ccode) : "a" (__pa(addr)) : "cc", "memory" );

 	return ccode;
 }
 #endif

 /*
  * Input :
  *   devno - device number
  *   ps	   - pointer to sense ID data area
  * Output : none
  */
 static void
 VM_virtual_device_info (__u16 devno, struct senseid *ps)
 {
 	static struct {
 		int vrdcvcla, vrdcvtyp, cu_type;
 	} vm_devices[] = {
 		{ 0x08, 0x01, 0x3480 },
 		{ 0x08, 0x02, 0x3430 },
 		{ 0x08, 0x10, 0x3420 },
 		{ 0x08, 0x42, 0x3424 },
 		{ 0x08, 0x44, 0x9348 },
 		{ 0x08, 0x81, 0x3490 },
 		{ 0x08, 0x82, 0x3422 },
 		{ 0x10, 0x41, 0x1403 },
 		{ 0x10, 0x42, 0x3211 },
 		{ 0x10, 0x43, 0x3203 },
 		{ 0x10, 0x45, 0x3800 },
 		{ 0x10, 0x47, 0x3262 },
 		{ 0x10, 0x48, 0x3820 },
 		{ 0x10, 0x49, 0x3800 },
 		{ 0x10, 0x4a, 0x4245 },
 		{ 0x10, 0x4b, 0x4248 },
 		{ 0x10, 0x4d, 0x3800 },
 		{ 0x10, 0x4e, 0x3820 },
 		{ 0x10, 0x4f, 0x3820 },
 		{ 0x10, 0x82, 0x2540 },
 		{ 0x10, 0x84, 0x3525 },
 		{ 0x20, 0x81, 0x2501 },
 		{ 0x20, 0x82, 0x2540 },
 		{ 0x20, 0x84, 0x3505 },
 		{ 0x40, 0x01, 0x3278 },
 		{ 0x40, 0x04, 0x3277 },
 		{ 0x40, 0x80, 0x2250 },
 		{ 0x40, 0xc0, 0x5080 },
 		{ 0x80, 0x00, 0x3215 },
 	};
 	struct diag210 diag_data;
 	int ccode, i;

 	CIO_TRACE_EVENT (4, "VMvdinf");

 	diag_data = (struct diag210) {
 		.vrdcdvno = devno,
 		.vrdclen = sizeof (diag_data),
 	};

 	ccode = diag210 (&diag_data);
 	ps->reserved = 0xff;

 	/* Special case for bloody osa devices. */
 	if (diag_data.vrdcvcla == 0x02 &&
 	    diag_data.vrdcvtyp == 0x20) {
 		ps->cu_type = 0x3088;
 		ps->cu_model = 0x60;
 		return;
 	}
 	for (i = 0; i < sizeof(vm_devices) / sizeof(vm_devices[0]); i++)
 		if (diag_data.vrdcvcla == vm_devices[i].vrdcvcla &&
 		    diag_data.vrdcvtyp == vm_devices[i].vrdcvtyp) {
 			ps->cu_type = vm_devices[i].cu_type;
 			return;
 		}
 	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);
 }

 /*
  * Start Sense ID helper function.
  * Try to obtain the 'control unit'/'device type' information
  *  associated with the subchannel.
  */
 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;
 	if (sch->schib.pmcw.pim != 0x80) {
 		/* more than one path installed. */
 		ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
 		ccw->cda = 0;
 		ccw->count = 0;
 		ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
 		ccw++;
 	}
 	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) {
 		if ((sch->opm & cdev->private->imask) != 0 &&
 		    cdev->private->iretry > 0) {
 			cdev->private->iretry--;
 			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)
 {
 	int ret;

 	memset (&cdev->private->senseid, 0, sizeof (struct senseid));
 	cdev->private->senseid.cu_type = 0xFFFF;
 	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);
 }

 /*
  * Called from interrupt context to check if a valid answer
  * to Sense ID was received.
  */
 static int
 ccw_device_check_sense_id(struct ccw_device *cdev)
 {
 	struct subchannel *sch;
 	struct irb *irb;

 	sch = to_subchannel(cdev->dev.parent);
 	irb = &cdev->private->irb;
 	/* Did we get a proper answer ? */
 	if (cdev->private->senseid.cu_type != 0xFFFF &&
 	    cdev->private->senseid.reserved == 0xFF) {
 		if (irb->scsw.count < sizeof (struct senseid) - 8)
 			cdev->private->flags.esid = 1;
 		return 0; /* Success */
 	}
 	/* Check the error cases. */
 	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
 		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(2, "SenseID : device %04x on Subchannel "
 			      "0.%x.%04x reports cmd reject\n",
 			      cdev->private->devno, sch->schid.ssid,
 			      sch->schid.sch_no);
 		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->ssid, cdev->private->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.cc == 3) {
 		if ((sch->orb.lpm &
 		     sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
 			CIO_MSG_EVENT(2, "SenseID : path %02X for device %04x "
 				      "on subchannel 0.%x.%04x is "
 				      "'not operational'\n", sch->orb.lpm,
 				      cdev->private->devno, sch->schid.ssid,
 				      sch->schid.sch_no);
 		return -EACCES;
 	}
 	/* 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->devno, sch->schid.ssid, sch->schid.sch_no,
 		      irb->scsw.dstat, irb->scsw.cstat);
 	return -EAGAIN;
 }

 /*
  * Got interrupt for Sense ID.
  */
 void
 ccw_device_sense_id_irq(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	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.stctl ==
 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 		if ((irb->scsw.cc == 1) || !irb->scsw.actl) {
 			ret = __ccw_device_sense_id_start(cdev);
 			if (ret && ret != -EBUSY)
 				ccw_device_sense_id_done(cdev, ret);
 		}
 		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) {
 			VM_virtual_device_info (cdev->private->devno,
 						&cdev->private->senseid);
 			if (cdev->private->senseid.cu_type != 0xFFFF) {
 				/* Got the device information from VM. */
 				ccw_device_sense_id_done(cdev, 0);
 				return;
 			}
 		}
 		/*
 		 * If we can't couldn't identify the device type we
 		 *  consider the device "not operational".
 		 */
 		ccw_device_sense_id_done(cdev, -ENODEV);
 		break;
 	}
 }

 EXPORT_SYMBOL(diag210);
	/*
	* drivers/s390/cio/device_id.c
	*
	* 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.
	*/

	#include <linux/module.h>
	#include <linux/config.h>
	#include <linux/init.h>

	#include <asm/ccwdev.h>
	#include <asm/delay.h>
	#include <asm/cio.h>
	#include <asm/lowcore.h>

	#include "cio.h"
	#include "cio_debug.h"
	#include "css.h"
	#include "device.h"
	#include "ioasm.h"

	/*
	* diag210 is used under VM to get information about a virtual device
	*/
	#ifdef CONFIG_64BIT
	int
	diag210(struct diag210 * addr)
	{
	/*
	* diag 210 needs its data below the 2GB border, so we
	* use a static data area to be sure
	*/
	static struct diag210 diag210_tmp;
	static DEFINE_SPINLOCK(diag210_lock);
	unsigned long flags;
	int ccode;

	spin_lock_irqsave(&diag210_lock, flags);
	diag210_tmp = *addr;

	asm volatile (
	" lhi %0,-1\n"
	" sam31\n"
	" diag %1,0,0x210\n"
	"0: ipm %0\n"
	" srl %0,28\n"
	"1: sam64\n"
	".section __ex_table,\"a\"\n"
	" .align 8\n"
	" .quad 0b,1b\n"
	".previous"
	: "=&d" (ccode) : "a" (__pa(&diag210_tmp)) : "cc", "memory" );

	*addr = diag210_tmp;
	spin_unlock_irqrestore(&diag210_lock, flags);

	return ccode;
	}
	#else
	int
	diag210(struct diag210 * addr)
	{
	int ccode;

	asm volatile (
	" lhi %0,-1\n"
	" diag %1,0,0x210\n"
	"0: ipm %0\n"
	" srl %0,28\n"
	"1:\n"
	".section __ex_table,\"a\"\n"
	" .align 4\n"
	" .long 0b,1b\n"
	".previous"
	: "=&d" (ccode) : "a" (__pa(addr)) : "cc", "memory" );

	return ccode;
	}
	#endif

	/*
	* Input :
	* devno - device number
	* ps - pointer to sense ID data area
	* Output : none
	*/
	static void
	VM_virtual_device_info (__u16 devno, struct senseid *ps)
	{
	static struct {
	int vrdcvcla, vrdcvtyp, cu_type;
	} vm_devices[] = {
	{ 0x08, 0x01, 0x3480 },
	{ 0x08, 0x02, 0x3430 },
	{ 0x08, 0x10, 0x3420 },
	{ 0x08, 0x42, 0x3424 },
	{ 0x08, 0x44, 0x9348 },
	{ 0x08, 0x81, 0x3490 },
	{ 0x08, 0x82, 0x3422 },
	{ 0x10, 0x41, 0x1403 },
	{ 0x10, 0x42, 0x3211 },
	{ 0x10, 0x43, 0x3203 },
	{ 0x10, 0x45, 0x3800 },
	{ 0x10, 0x47, 0x3262 },
	{ 0x10, 0x48, 0x3820 },
	{ 0x10, 0x49, 0x3800 },
	{ 0x10, 0x4a, 0x4245 },
	{ 0x10, 0x4b, 0x4248 },
	{ 0x10, 0x4d, 0x3800 },
	{ 0x10, 0x4e, 0x3820 },
	{ 0x10, 0x4f, 0x3820 },
	{ 0x10, 0x82, 0x2540 },
	{ 0x10, 0x84, 0x3525 },
	{ 0x20, 0x81, 0x2501 },
	{ 0x20, 0x82, 0x2540 },
	{ 0x20, 0x84, 0x3505 },
	{ 0x40, 0x01, 0x3278 },
	{ 0x40, 0x04, 0x3277 },
	{ 0x40, 0x80, 0x2250 },
	{ 0x40, 0xc0, 0x5080 },
	{ 0x80, 0x00, 0x3215 },
	};
	struct diag210 diag_data;
	int ccode, i;

	CIO_TRACE_EVENT (4, "VMvdinf");

	diag_data = (struct diag210) {
	.vrdcdvno = devno,
	.vrdclen = sizeof (diag_data),
	};

	ccode = diag210 (&diag_data);
	ps->reserved = 0xff;

	/* Special case for bloody osa devices. */
	if (diag_data.vrdcvcla == 0x02 &&
	diag_data.vrdcvtyp == 0x20) {
	ps->cu_type = 0x3088;
	ps->cu_model = 0x60;
	return;
	}
	for (i = 0; i < sizeof(vm_devices) / sizeof(vm_devices[0]); i++)
	if (diag_data.vrdcvcla == vm_devices[i].vrdcvcla &&
	diag_data.vrdcvtyp == vm_devices[i].vrdcvtyp) {
	ps->cu_type = vm_devices[i].cu_type;
	return;
	}
	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);
	}

	/*
	* Start Sense ID helper function.
	* Try to obtain the 'control unit'/'device type' information
	* associated with the subchannel.
	*/
	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;
	if (sch->schib.pmcw.pim != 0x80) {
	/* more than one path installed. */
	ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
	ccw->cda = 0;
	ccw->count = 0;
	ccw->flags = CCW_FLAG_SLI \| CCW_FLAG_CC;
	ccw++;
	}
	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) {
	if ((sch->opm & cdev->private->imask) != 0 &&
	cdev->private->iretry > 0) {
	cdev->private->iretry--;
	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)
	{
	int ret;

	memset (&cdev->private->senseid, 0, sizeof (struct senseid));
	cdev->private->senseid.cu_type = 0xFFFF;
	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);
	}

	/*
	* Called from interrupt context to check if a valid answer
	* to Sense ID was received.
	*/
	static int
	ccw_device_check_sense_id(struct ccw_device *cdev)
	{
	struct subchannel *sch;
	struct irb *irb;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	/* Did we get a proper answer ? */
	if (cdev->private->senseid.cu_type != 0xFFFF &&
	cdev->private->senseid.reserved == 0xFF) {
	if (irb->scsw.count < sizeof (struct senseid) - 8)
	cdev->private->flags.esid = 1;
	return 0; /* Success */
	}
	/* Check the error cases. */
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
	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(2, "SenseID : device %04x on Subchannel "
	"0.%x.%04x reports cmd reject\n",
	cdev->private->devno, sch->schid.ssid,
	sch->schid.sch_no);
	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->ssid, cdev->private->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.cc == 3) {
	if ((sch->orb.lpm &
	sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
	CIO_MSG_EVENT(2, "SenseID : path %02X for device %04x "
	"on subchannel 0.%x.%04x is "
	"'not operational'\n", sch->orb.lpm,
	cdev->private->devno, sch->schid.ssid,
	sch->schid.sch_no);
	return -EACCES;
	}
	/* 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->devno, sch->schid.ssid, sch->schid.sch_no,
	irb->scsw.dstat, irb->scsw.cstat);
	return -EAGAIN;
	}

	/*
	* Got interrupt for Sense ID.
	*/
	void
	ccw_device_sense_id_irq(struct ccw_device *cdev, enum dev_event dev_event)
	{
	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.stctl ==
	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
	if ((irb->scsw.cc == 1) \|\| !irb->scsw.actl) {
	ret = __ccw_device_sense_id_start(cdev);
	if (ret && ret != -EBUSY)
	ccw_device_sense_id_done(cdev, ret);
	}
	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) {
	VM_virtual_device_info (cdev->private->devno,
	&cdev->private->senseid);
	if (cdev->private->senseid.cu_type != 0xFFFF) {
	/* Got the device information from VM. */
	ccw_device_sense_id_done(cdev, 0);
	return;
	}
	}
	/*
	* If we can't couldn't identify the device type we
	* consider the device "not operational".
	*/
	ccw_device_sense_id_done(cdev, -ENODEV);
	break;
	}
	}

	EXPORT_SYMBOL(diag210);