367 lines
8.3 KiB
C
367 lines
8.3 KiB
C
|
/*
|
||
|
|
* Handling of internal CCW device requests.
|
||
|
|
*
|
||
|
|
* Copyright IBM Corp. 2009, 2011
|
||
|
|
* Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define KMSG_COMPONENT "cio"
|
||
|
|
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
|
||
|
|
|
||
|
|
#include <linux/types.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <asm/ccwdev.h>
|
||
|
|
#include <asm/cio.h>
|
||
|
|
|
||
|
|
#include "io_sch.h"
|
||
|
|
#include "cio.h"
|
||
|
|
#include "device.h"
|
||
|
|
#include "cio_debug.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* lpm_adjust - adjust path mask
|
||
|
|
* @lpm: path mask to adjust
|
||
|
|
* @mask: mask of available paths
|
||
|
|
*
|
||
|
|
* Shift @lpm right until @lpm and @mask have at least one bit in common or
|
||
|
|
* until @lpm is zero. Return the resulting lpm.
|
||
|
|
*/
|
||
|
|
int lpm_adjust(int lpm, int mask)
|
||
|
|
{
|
||
|
|
while (lpm && ((lpm & mask) == 0))
|
||
|
|
lpm >>= 1;
|
||
|
|
return lpm;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Adjust path mask to use next path and reset retry count. Return resulting
|
||
|
|
* path mask.
|
||
|
|
*/
|
||
|
|
static u16 ccwreq_next_path(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
|
||
|
|
if (!req->singlepath) {
|
||
|
|
req->mask = 0;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
req->retries = req->maxretries;
|
||
|
|
req->mask = lpm_adjust(req->mask >> 1, req->lpm);
|
||
|
|
out:
|
||
|
|
return req->mask;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Clean up device state and report to callback.
|
||
|
|
*/
|
||
|
|
static void ccwreq_stop(struct ccw_device *cdev, int rc)
|
||
|
|
{
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
|
||
|
|
if (req->done)
|
||
|
|
return;
|
||
|
|
req->done = 1;
|
||
|
|
ccw_device_set_timeout(cdev, 0);
|
||
|
|
memset(&cdev->private->irb, 0, sizeof(struct irb));
|
||
|
|
if (rc && rc != -ENODEV && req->drc)
|
||
|
|
rc = req->drc;
|
||
|
|
req->callback(cdev, req->data, rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* (Re-)Start the operation until retries and paths are exhausted.
|
||
|
|
*/
|
||
|
|
static void ccwreq_do(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
struct subchannel *sch = to_subchannel(cdev->dev.parent);
|
||
|
|
struct ccw1 *cp = req->cp;
|
||
|
|
int rc = -EACCES;
|
||
|
|
|
||
|
|
while (req->mask) {
|
||
|
|
if (req->retries-- == 0) {
|
||
|
|
/* Retries exhausted, try next path. */
|
||
|
|
ccwreq_next_path(cdev);
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
/* Perform start function. */
|
||
|
|
memset(&cdev->private->irb, 0, sizeof(struct irb));
|
||
|
|
rc = cio_start(sch, cp, (u8) req->mask);
|
||
|
|
if (rc == 0) {
|
||
|
|
/* I/O started successfully. */
|
||
|
|
ccw_device_set_timeout(cdev, req->timeout);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (rc == -ENODEV) {
|
||
|
|
/* Permanent device error. */
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
if (rc == -EACCES) {
|
||
|
|
/* Permant path error. */
|
||
|
|
ccwreq_next_path(cdev);
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
/* Temporary improper status. */
|
||
|
|
rc = cio_clear(sch);
|
||
|
|
if (rc)
|
||
|
|
break;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
ccwreq_stop(cdev, rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ccw_request_start - perform I/O request
|
||
|
|
* @cdev: ccw device
|
||
|
|
*
|
||
|
|
* Perform the I/O request specified by cdev->req.
|
||
|
|
*/
|
||
|
|
void ccw_request_start(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
|
||
|
|
if (req->singlepath) {
|
||
|
|
/* Try all paths twice to counter link flapping. */
|
||
|
|
req->mask = 0x8080;
|
||
|
|
} else
|
||
|
|
req->mask = req->lpm;
|
||
|
|
|
||
|
|
req->retries = req->maxretries;
|
||
|
|
req->mask = lpm_adjust(req->mask, req->lpm);
|
||
|
|
req->drc = 0;
|
||
|
|
req->done = 0;
|
||
|
|
req->cancel = 0;
|
||
|
|
if (!req->mask)
|
||
|
|
goto out_nopath;
|
||
|
|
ccwreq_do(cdev);
|
||
|
|
return;
|
||
|
|
|
||
|
|
out_nopath:
|
||
|
|
ccwreq_stop(cdev, -EACCES);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ccw_request_cancel - cancel running I/O request
|
||
|
|
* @cdev: ccw device
|
||
|
|
*
|
||
|
|
* Cancel the I/O request specified by cdev->req. Return non-zero if request
|
||
|
|
* has already finished, zero otherwise.
|
||
|
|
*/
|
||
|
|
int ccw_request_cancel(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct subchannel *sch = to_subchannel(cdev->dev.parent);
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
int rc;
|
||
|
|
|
||
|
|
if (req->done)
|
||
|
|
return 1;
|
||
|
|
req->cancel = 1;
|
||
|
|
rc = cio_clear(sch);
|
||
|
|
if (rc)
|
||
|
|
ccwreq_stop(cdev, rc);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Return the status of the internal I/O started on the specified ccw device.
|
||
|
|
* Perform BASIC SENSE if required.
|
||
|
|
*/
|
||
|
|
static enum io_status ccwreq_status(struct ccw_device *cdev, struct irb *lcirb)
|
||
|
|
{
|
||
|
|
struct irb *irb = &cdev->private->irb;
|
||
|
|
struct cmd_scsw *scsw = &irb->scsw.cmd;
|
||
|
|
enum uc_todo todo;
|
||
|
|
|
||
|
|
/* Perform BASIC SENSE if needed. */
|
||
|
|
if (ccw_device_accumulate_and_sense(cdev, lcirb))
|
||
|
|
return IO_RUNNING;
|
||
|
|
/* Check for halt/clear interrupt. */
|
||
|
|
if (scsw->fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
|
||
|
|
return IO_KILLED;
|
||
|
|
/* Check for path error. */
|
||
|
|
if (scsw->cc == 3 || scsw->pno)
|
||
|
|
return IO_PATH_ERROR;
|
||
|
|
/* Handle BASIC SENSE data. */
|
||
|
|
if (irb->esw.esw0.erw.cons) {
|
||
|
|
CIO_TRACE_EVENT(2, "sensedata");
|
||
|
|
CIO_HEX_EVENT(2, &cdev->private->dev_id,
|
||
|
|
sizeof(struct ccw_dev_id));
|
||
|
|
CIO_HEX_EVENT(2, &cdev->private->irb.ecw, SENSE_MAX_COUNT);
|
||
|
|
/* Check for command reject. */
|
||
|
|
if (irb->ecw[0] & SNS0_CMD_REJECT)
|
||
|
|
return IO_REJECTED;
|
||
|
|
/* Ask the driver what to do */
|
||
|
|
if (cdev->drv && cdev->drv->uc_handler) {
|
||
|
|
todo = cdev->drv->uc_handler(cdev, lcirb);
|
||
|
|
CIO_TRACE_EVENT(2, "uc_response");
|
||
|
|
CIO_HEX_EVENT(2, &todo, sizeof(todo));
|
||
|
|
switch (todo) {
|
||
|
|
case UC_TODO_RETRY:
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
case UC_TODO_RETRY_ON_NEW_PATH:
|
||
|
|
return IO_PATH_ERROR;
|
||
|
|
case UC_TODO_STOP:
|
||
|
|
return IO_REJECTED;
|
||
|
|
default:
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/* Assume that unexpected SENSE data implies an error. */
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
}
|
||
|
|
/* Check for channel errors. */
|
||
|
|
if (scsw->cstat != 0)
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
/* Check for device errors. */
|
||
|
|
if (scsw->dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
/* Check for final state. */
|
||
|
|
if (!(scsw->dstat & DEV_STAT_DEV_END))
|
||
|
|
return IO_RUNNING;
|
||
|
|
/* Check for other improper status. */
|
||
|
|
if (scsw->cc == 1 && (scsw->stctl & SCSW_STCTL_ALERT_STATUS))
|
||
|
|
return IO_STATUS_ERROR;
|
||
|
|
return IO_DONE;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Log ccw request status.
|
||
|
|
*/
|
||
|
|
static void ccwreq_log_status(struct ccw_device *cdev, enum io_status status)
|
||
|
|
{
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
struct {
|
||
|
|
struct ccw_dev_id dev_id;
|
||
|
|
u16 retries;
|
||
|
|
u8 lpm;
|
||
|
|
u8 status;
|
||
|
|
} __attribute__ ((packed)) data;
|
||
|
|
data.dev_id = cdev->private->dev_id;
|
||
|
|
data.retries = req->retries;
|
||
|
|
data.lpm = (u8) req->mask;
|
||
|
|
data.status = (u8) status;
|
||
|
|
CIO_TRACE_EVENT(2, "reqstat");
|
||
|
|
CIO_HEX_EVENT(2, &data, sizeof(data));
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ccw_request_handler - interrupt handler for I/O request procedure.
|
||
|
|
* @cdev: ccw device
|
||
|
|
*
|
||
|
|
* Handle interrupt during I/O request procedure.
|
||
|
|
*/
|
||
|
|
void ccw_request_handler(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct irb *irb = this_cpu_ptr(&cio_irb);
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
enum io_status status;
|
||
|
|
int rc = -EOPNOTSUPP;
|
||
|
|
|
||
|
|
/* Check status of I/O request. */
|
||
|
|
status = ccwreq_status(cdev, irb);
|
||
|
|
if (req->filter)
|
||
|
|
status = req->filter(cdev, req->data, irb, status);
|
||
|
|
if (status != IO_RUNNING)
|
||
|
|
ccw_device_set_timeout(cdev, 0);
|
||
|
|
if (status != IO_DONE && status != IO_RUNNING)
|
||
|
|
ccwreq_log_status(cdev, status);
|
||
|
|
switch (status) {
|
||
|
|
case IO_DONE:
|
||
|
|
break;
|
||
|
|
case IO_RUNNING:
|
||
|
|
return;
|
||
|
|
case IO_REJECTED:
|
||
|
|
goto err;
|
||
|
|
case IO_PATH_ERROR:
|
||
|
|
goto out_next_path;
|
||
|
|
case IO_STATUS_ERROR:
|
||
|
|
goto out_restart;
|
||
|
|
case IO_KILLED:
|
||
|
|
/* Check if request was cancelled on purpose. */
|
||
|
|
if (req->cancel) {
|
||
|
|
rc = -EIO;
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
goto out_restart;
|
||
|
|
}
|
||
|
|
/* Check back with request initiator. */
|
||
|
|
if (!req->check)
|
||
|
|
goto out;
|
||
|
|
switch (req->check(cdev, req->data)) {
|
||
|
|
case 0:
|
||
|
|
break;
|
||
|
|
case -EAGAIN:
|
||
|
|
goto out_restart;
|
||
|
|
case -EACCES:
|
||
|
|
goto out_next_path;
|
||
|
|
default:
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
out:
|
||
|
|
ccwreq_stop(cdev, 0);
|
||
|
|
return;
|
||
|
|
|
||
|
|
out_next_path:
|
||
|
|
/* Try next path and restart I/O. */
|
||
|
|
if (!ccwreq_next_path(cdev)) {
|
||
|
|
rc = -EACCES;
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
out_restart:
|
||
|
|
/* Restart. */
|
||
|
|
ccwreq_do(cdev);
|
||
|
|
return;
|
||
|
|
err:
|
||
|
|
ccwreq_stop(cdev, rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ccw_request_timeout - timeout handler for I/O request procedure
|
||
|
|
* @cdev: ccw device
|
||
|
|
*
|
||
|
|
* Handle timeout during I/O request procedure.
|
||
|
|
*/
|
||
|
|
void ccw_request_timeout(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
struct subchannel *sch = to_subchannel(cdev->dev.parent);
|
||
|
|
struct ccw_request *req = &cdev->private->req;
|
||
|
|
int rc = -ENODEV, chp;
|
||
|
|
|
||
|
|
if (cio_update_schib(sch))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
for (chp = 0; chp < 8; chp++) {
|
||
|
|
if ((0x80 >> chp) & sch->schib.pmcw.lpum)
|
||
|
|
pr_warn("%s: No interrupt was received within %lus (CS=%02x, DS=%02x, CHPID=%x.%02x)\n",
|
||
|
|
dev_name(&cdev->dev), req->timeout / HZ,
|
||
|
|
scsw_cstat(&sch->schib.scsw),
|
||
|
|
scsw_dstat(&sch->schib.scsw),
|
||
|
|
sch->schid.cssid,
|
||
|
|
sch->schib.pmcw.chpid[chp]);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!ccwreq_next_path(cdev)) {
|
||
|
|
/* set the final return code for this request */
|
||
|
|
req->drc = -ETIME;
|
||
|
|
}
|
||
|
|
rc = cio_clear(sch);
|
||
|
|
if (rc)
|
||
|
|
goto err;
|
||
|
|
return;
|
||
|
|
|
||
|
|
err:
|
||
|
|
ccwreq_stop(cdev, rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ccw_request_notoper - notoper handler for I/O request procedure
|
||
|
|
* @cdev: ccw device
|
||
|
|
*
|
||
|
|
* Handle notoper during I/O request procedure.
|
||
|
|
*/
|
||
|
|
void ccw_request_notoper(struct ccw_device *cdev)
|
||
|
|
{
|
||
|
|
ccwreq_stop(cdev, -ENODEV);
|
||
|
|
}
|