linux/drivers/s390/cio/device_id.c
Peter Oberparleiter 6f52ac2971 [S390] cio: make sense id procedure work with partial hardware response
In some cases the current sense id procedure trips over incomplete
hardware responses. In these cases, checking against the preset value
of 0xFFFF is not enough. More critically, the VM DIAG call will always be
considered to have provided data after such an incident, even if it was not
successful at all.

The solution is to always initialize the control unit data before doing a
sense id call. Check the condition code before considering the control unit
data. And initialize again, before evaluating the VM data.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-02-05 16:50:52 +01:00

323 lines
8.5 KiB
C

/*
* 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/init.h>
#include <linux/kernel.h>
#include <asm/ccwdev.h>
#include <asm/delay.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"
/**
* vm_vdev_to_cu_type - Convert vm virtual device into control unit type
* for certain devices.
* @class: virtual device class
* @type: virtual device type
*
* Returns control unit type if a match was made or %0xffff otherwise.
*/
static int vm_vdev_to_cu_type(int class, int type)
{
static struct {
int class, type, 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 },
};
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;
return 0xffff;
}
/**
* diag_get_dev_info - retrieve device information via DIAG X'210'
* @devno: device number
* @ps: pointer to sense ID data area
*
* Returns zero on success, non-zero otherwise.
*/
static int diag_get_dev_info(u16 devno, struct senseid *ps)
{
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);
return -ENODEV;
}
/*
* 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;
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)
{
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);
}
/*
* 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;
/* Check the error cases. */
if (irb->scsw.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(2, "SenseID : device %04x on Subchannel "
"0.%x.%04x reports cmd reject\n",
cdev->private->dev_id.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->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.cc == 3) {
u8 lpm;
lpm = to_io_private(sch)->orb.lpm;
if ((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", lpm,
cdev->private->dev_id.devno,
sch->schid.ssid, sch->schid.sch_no);
return -EACCES;
}
/* Did we get a proper answer ? */
if (irb->scsw.cc == 0 && 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 */
}
/* 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.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)
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;
ccw_device_sense_id_done(cdev, ret);
break;
}
}