[mirror_ubuntu-artful-kernel.git] / drivers / s390 / cio / device_id.c

/*
 * drivers/s390/cio/device_id.c
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *			 IBM Corporation
 *    Author(s): Cornelia Huck(cohuck@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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/cio/device_id.c
	3	*
	4	* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
	5	* IBM Corporation
	6	* Author(s): Cornelia Huck(cohuck@de.ibm.com)
	7	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	8	*
	9	* Sense ID functions.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/config.h>
	14	#include <linux/init.h>
	15
	16	#include <asm/ccwdev.h>
	17	#include <asm/delay.h>
	18	#include <asm/cio.h>
	19	#include <asm/lowcore.h>
	20
	21	#include "cio.h"
	22	#include "cio_debug.h"
	23	#include "css.h"
	24	#include "device.h"
	25	#include "ioasm.h"
	26
	27	/*
	28	* diag210 is used under VM to get information about a virtual device
	29	*/
347a8dc3	30	#ifdef CONFIG_64BIT
1da177e4 LT	31	int
	32	diag210(struct diag210 * addr)
	33	{
	34	/*
	35	* diag 210 needs its data below the 2GB border, so we
	36	* use a static data area to be sure
	37	*/
	38	static struct diag210 diag210_tmp;
	39	static DEFINE_SPINLOCK(diag210_lock);
	40	unsigned long flags;
	41	int ccode;
	42
	43	spin_lock_irqsave(&diag210_lock, flags);
	44	diag210_tmp = *addr;
	45
	46	asm volatile (
	47	" lhi %0,-1\n"
	48	" sam31\n"
	49	" diag %1,0,0x210\n"
	50	"0: ipm %0\n"
	51	" srl %0,28\n"
	52	"1: sam64\n"
	53	".section __ex_table,\"a\"\n"
	54	" .align 8\n"
	55	" .quad 0b,1b\n"
	56	".previous"
	57	: "=&d" (ccode) : "a" (__pa(&diag210_tmp)) : "cc", "memory" );
	58
	59	*addr = diag210_tmp;
	60	spin_unlock_irqrestore(&diag210_lock, flags);
	61
	62	return ccode;
	63	}
	64	#else
	65	int
	66	diag210(struct diag210 * addr)
	67	{
	68	int ccode;
	69
	70	asm volatile (
	71	" lhi %0,-1\n"
	72	" diag %1,0,0x210\n"
	73	"0: ipm %0\n"
	74	" srl %0,28\n"
	75	"1:\n"
	76	".section __ex_table,\"a\"\n"
	77	" .align 4\n"
	78	" .long 0b,1b\n"
	79	".previous"
	80	: "=&d" (ccode) : "a" (__pa(addr)) : "cc", "memory" );
	81
	82	return ccode;
	83	}
	84	#endif
	85
	86	/*
	87	* Input :
	88	* devno - device number
	89	* ps - pointer to sense ID data area
	90	* Output : none
	91	*/
	92	static void
	93	VM_virtual_device_info (__u16 devno, struct senseid *ps)
	94	{
95	static struct {
96	int vrdcvcla, vrdcvtyp, cu_type;
97	} vm_devices[] = {
98	{ 0x08, 0x01, 0x3480 },
99	{ 0x08, 0x02, 0x3430 },
100	{ 0x08, 0x10, 0x3420 },
101	{ 0x08, 0x42, 0x3424 },
102	{ 0x08, 0x44, 0x9348 },
103	{ 0x08, 0x81, 0x3490 },
104	{ 0x08, 0x82, 0x3422 },
105	{ 0x10, 0x41, 0x1403 },
106	{ 0x10, 0x42, 0x3211 },
107	{ 0x10, 0x43, 0x3203 },
108	{ 0x10, 0x45, 0x3800 },
109	{ 0x10, 0x47, 0x3262 },
110	{ 0x10, 0x48, 0x3820 },
111	{ 0x10, 0x49, 0x3800 },
112	{ 0x10, 0x4a, 0x4245 },
113	{ 0x10, 0x4b, 0x4248 },
114	{ 0x10, 0x4d, 0x3800 },
115	{ 0x10, 0x4e, 0x3820 },
116	{ 0x10, 0x4f, 0x3820 },
117	{ 0x10, 0x82, 0x2540 },
118	{ 0x10, 0x84, 0x3525 },
119	{ 0x20, 0x81, 0x2501 },
120	{ 0x20, 0x82, 0x2540 },
121	{ 0x20, 0x84, 0x3505 },
122	{ 0x40, 0x01, 0x3278 },
123	{ 0x40, 0x04, 0x3277 },
124	{ 0x40, 0x80, 0x2250 },
125	{ 0x40, 0xc0, 0x5080 },
126	{ 0x80, 0x00, 0x3215 },
127	};
128	struct diag210 diag_data;
129	int ccode, i;
130
131	CIO_TRACE_EVENT (4, "VMvdinf");
132
133	diag_data = (struct diag210) {
134	.vrdcdvno = devno,
135	.vrdclen = sizeof (diag_data),
136	};
137
138	ccode = diag210 (&diag_data);
139	ps->reserved = 0xff;
140
141	/* Special case for bloody osa devices. */
142	if (diag_data.vrdcvcla == 0x02 &&
143	diag_data.vrdcvtyp == 0x20) {
144	ps->cu_type = 0x3088;
145	ps->cu_model = 0x60;
146	return;
147	}
148	for (i = 0; i < sizeof(vm_devices) / sizeof(vm_devices[0]); i++)
149	if (diag_data.vrdcvcla == vm_devices[i].vrdcvcla &&
150	diag_data.vrdcvtyp == vm_devices[i].vrdcvtyp) {
151	ps->cu_type = vm_devices[i].cu_type;
152	return;
153	}
154	CIO_MSG_EVENT(0, "DIAG X'210' for device %04X returned (cc = %d):"
155	"vdev class : %02X, vdev type : %04X \n ... "
156	"rdev class : %02X, rdev type : %04X, "
157	"rdev model: %02X\n",
158	devno, ccode,
159	diag_data.vrdcvcla, diag_data.vrdcvtyp,
160	diag_data.vrdcrccl, diag_data.vrdccrty,
161	diag_data.vrdccrmd);
162	}
163
164	/*
165	* Start Sense ID helper function.
166	* Try to obtain the 'control unit'/'device type' information
167	* associated with the subchannel.
168	*/
169	static int
170	__ccw_device_sense_id_start(struct ccw_device *cdev)
171	{
172	struct subchannel *sch;
173	struct ccw1 *ccw;
174	int ret;
175
176	sch = to_subchannel(cdev->dev.parent);
177	/* Setup sense channel program. */
178	ccw = cdev->private->iccws;
179	if (sch->schib.pmcw.pim != 0x80) {
180	/* more than one path installed. */
181	ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
182	ccw->cda = 0;
183	ccw->count = 0;
184	ccw->flags = CCW_FLAG_SLI \| CCW_FLAG_CC;
185	ccw++;
186	}
187	ccw->cmd_code = CCW_CMD_SENSE_ID;
188	ccw->cda = (__u32) __pa (&cdev->private->senseid);
189	ccw->count = sizeof (struct senseid);
190	ccw->flags = CCW_FLAG_SLI;
191
192	/* Reset device status. */
193	memset(&cdev->private->irb, 0, sizeof(struct irb));
194
195	/* Try on every path. */
196	ret = -ENODEV;
197	while (cdev->private->imask != 0) {
198	if ((sch->opm & cdev->private->imask) != 0 &&
199	cdev->private->iretry > 0) {
200	cdev->private->iretry--;
201	ret = cio_start (sch, cdev->private->iccws,
202	cdev->private->imask);
203	/* ret is 0, -EBUSY, -EACCES or -ENODEV */
204	if (ret != -EACCES)
205	return ret;
206	}
207	cdev->private->imask >>= 1;
208	cdev->private->iretry = 5;
209	}
210	return ret;
211	}
212
213	void
214	ccw_device_sense_id_start(struct ccw_device *cdev)
215	{
216	int ret;
217
218	memset (&cdev->private->senseid, 0, sizeof (struct senseid));
219	cdev->private->senseid.cu_type = 0xFFFF;
220	cdev->private->imask = 0x80;
221	cdev->private->iretry = 5;
222	ret = __ccw_device_sense_id_start(cdev);
223	if (ret && ret != -EBUSY)
224	ccw_device_sense_id_done(cdev, ret);
225	}
226
227	/*
228	* Called from interrupt context to check if a valid answer
229	* to Sense ID was received.
230	*/
231	static int
232	ccw_device_check_sense_id(struct ccw_device *cdev)
233	{
234	struct subchannel *sch;
235	struct irb *irb;
236
237	sch = to_subchannel(cdev->dev.parent);
238	irb = &cdev->private->irb;
239	/* Did we get a proper answer ? */
240	if (cdev->private->senseid.cu_type != 0xFFFF &&
241	cdev->private->senseid.reserved == 0xFF) {
242	if (irb->scsw.count < sizeof (struct senseid) - 8)
243	cdev->private->flags.esid = 1;
244	return 0; /* Success */
245	}
246	/* Check the error cases. */
247	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC \| SCSW_FCTL_CLEAR_FUNC))
248	return -ETIME;
249	if (irb->esw.esw0.erw.cons && (irb->ecw[0] & SNS0_CMD_REJECT)) {
250	/*
251	* if the device doesn't support the SenseID
252	* command further retries wouldn't help ...
253	* NB: We don't check here for intervention required like we
254	* did before, because tape devices with no tape inserted
255	* may present this status in conjunction with the
256	* sense id information. So, for intervention required,
257	* we use the "whack it until it talks" strategy...
258	*/
fb6958a5 CH	259	CIO_MSG_EVENT(2, "SenseID : device %04x on Subchannel "
	260	"0.%x.%04x reports cmd reject\n",
	261	cdev->private->devno, sch->schid.ssid,
	262	sch->schid.sch_no);
1da177e4 LT	263	return -EOPNOTSUPP;
	264	}
	265	if (irb->esw.esw0.erw.cons) {
fb6958a5	266	CIO_MSG_EVENT(2, "SenseID : UC on dev 0.%x.%04x, "
1da177e4 LT	267	"lpum %02X, cnt %02d, sns :"
1da177e4 LT	268	" %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
fb6958a5	269	cdev->private->ssid, cdev->private->devno,
1da177e4 LT	270	irb->esw.esw0.sublog.lpum,
	271	irb->esw.esw0.erw.scnt,
	272	irb->ecw[0], irb->ecw[1],
	273	irb->ecw[2], irb->ecw[3],
	274	irb->ecw[4], irb->ecw[5],
	275	irb->ecw[6], irb->ecw[7]);
	276	return -EAGAIN;
	277	}
	278	if (irb->scsw.cc == 3) {
	279	if ((sch->orb.lpm &
	280	sch->schib.pmcw.pim & sch->schib.pmcw.pam) != 0)
fb6958a5 CH	281	CIO_MSG_EVENT(2, "SenseID : path %02X for device %04x "
	282	"on subchannel 0.%x.%04x is "
	283	"'not operational'\n", sch->orb.lpm,
	284	cdev->private->devno, sch->schid.ssid,
a8237fc4	285	sch->schid.sch_no);
1da177e4 LT	286	return -EACCES;
	287	}
	288	/* Hmm, whatever happened, try again. */
	289	CIO_MSG_EVENT(2, "SenseID : start_IO() for device %04x on "
fb6958a5 CH	290	"subchannel 0.%x.%04x returns status %02X%02X\n",
fb6958a5 CH	291	cdev->private->devno, sch->schid.ssid, sch->schid.sch_no,
1da177e4 LT	292	irb->scsw.dstat, irb->scsw.cstat);
	293	return -EAGAIN;
	294	}
	295
	296	/*
	297	* Got interrupt for Sense ID.
	298	*/
	299	void
	300	ccw_device_sense_id_irq(struct ccw_device *cdev, enum dev_event dev_event)
	301	{
	302	struct subchannel *sch;
	303	struct irb *irb;
	304	int ret;
	305
	306	sch = to_subchannel(cdev->dev.parent);
	307	irb = (struct irb *) __LC_IRB;
	308	/* Retry sense id, if needed. */
	309	if (irb->scsw.stctl ==
	310	(SCSW_STCTL_STATUS_PEND \| SCSW_STCTL_ALERT_STATUS)) {
	311	if ((irb->scsw.cc == 1) \|\| !irb->scsw.actl) {
	312	ret = __ccw_device_sense_id_start(cdev);
	313	if (ret && ret != -EBUSY)
	314	ccw_device_sense_id_done(cdev, ret);
	315	}
	316	return;
	317	}
	318	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
	319	return;
	320	ret = ccw_device_check_sense_id(cdev);
	321	memset(&cdev->private->irb, 0, sizeof(struct irb));
	322	switch (ret) {
	323	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN or -EACCES */
	324	case 0: /* Sense id succeeded. */
	325	case -ETIME: /* Sense id stopped by timeout. */
	326	ccw_device_sense_id_done(cdev, ret);
	327	break;
	328	case -EACCES: /* channel is not operational. */
	329	sch->lpm &= ~cdev->private->imask;
	330	cdev->private->imask >>= 1;
	331	cdev->private->iretry = 5;
	332	/* fall through. */
	333	case -EAGAIN: /* try again. */
	334	ret = __ccw_device_sense_id_start(cdev);
	335	if (ret == 0 \|\| ret == -EBUSY)
	336	break;
	337	/* fall through. */
	338	default: /* Sense ID failed. Try asking VM. */
	339	if (MACHINE_IS_VM) {
	340	VM_virtual_device_info (cdev->private->devno,
	341	&cdev->private->senseid);
	342	if (cdev->private->senseid.cu_type != 0xFFFF) {
	343	/* Got the device information from VM. */
	344	ccw_device_sense_id_done(cdev, 0);
	345	return;
	346	}
	347	}
	348	/*
	349	* If we can't couldn't identify the device type we
	350	* consider the device "not operational".
	351	*/
	352	ccw_device_sense_id_done(cdev, -ENODEV);
	353	break;
	354	}
	355	}
356
357	EXPORT_SYMBOL(diag210);