/**
* 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;
}
/*
* (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);
}
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) {
ccwreq_next_path(cdev);
continue;
}
memset(&cdev->private->irb, 0, sizeof(struct irb));
rc = cio_start(sch, cp, (u8) req->mask);
if (rc == 0) {
ccw_device_set_timeout(cdev, req->timeout);
return;
}
if (rc == -ENODEV) {
break;
}
if (rc == -EACCES) {
ccwreq_next_path(cdev);
continue;
}
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);
}
