[S390] ccwreq: add ability to use all paths

Change the ccwrequest infrastructure to use more than one channel
path per start I/O. A flag "singlepath" is added to struct
ccw_request - if set, the old behavior is used. This flag is set
for all exploiters of the ccwrequest infrastructure - so there
is no functional change through this patch.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2010-08-09 18:12:53 +02:00 committed by Martin Schwidefsky
parent 7cd403142d
commit 982bdf8146
4 changed files with 22 additions and 7 deletions

View file

@ -38,9 +38,13 @@ 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;
}
@ -113,8 +117,12 @@ void ccw_request_start(struct ccw_device *cdev)
{
struct ccw_request *req = &cdev->private->req;
/* Try all paths twice to counter link flapping. */
req->mask = 0x8080;
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;

View file

@ -216,6 +216,7 @@ void ccw_device_sense_id_start(struct ccw_device *cdev)
req->timeout = SENSE_ID_TIMEOUT;
req->maxretries = SENSE_ID_RETRIES;
req->lpm = sch->schib.pmcw.pam & sch->opm;
req->singlepath = 1;
req->check = snsid_check;
req->callback = snsid_callback;
ccw_request_start(cdev);

View file

@ -208,6 +208,7 @@ static void spid_start(struct ccw_device *cdev)
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = 0x80;
req->singlepath = 1;
req->callback = spid_callback;
spid_do(cdev);
}
@ -420,6 +421,7 @@ static void verify_start(struct ccw_device *cdev)
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = 0x80;
req->singlepath = 1;
if (cdev->private->flags.pgroup) {
CIO_TRACE_EVENT(4, "snid");
CIO_HEX_EVENT(4, devid, sizeof(*devid));
@ -507,6 +509,7 @@ void ccw_device_disband_start(struct ccw_device *cdev)
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = sch->schib.pmcw.pam & sch->opm;
req->singlepath = 1;
req->callback = disband_callback;
fn = SPID_FUNC_DISBAND;
if (cdev->private->flags.mpath)
@ -560,6 +563,7 @@ void ccw_device_stlck_start(struct ccw_device *cdev, void *data, void *buf1,
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = sch->schib.pmcw.pam & sch->opm;
req->singlepath = 1;
req->data = data;
req->callback = stlck_callback;
stlck_build_cp(cdev, buf1, buf2);

View file

@ -92,11 +92,12 @@ enum io_status {
* @filter: optional callback to adjust request status based on IRB data
* @callback: final callback
* @data: user-defined pointer passed to all callbacks
* @singlepath: if set, use only one path from @lpm per start I/O
* @cancel: non-zero if request was cancelled
* @done: non-zero if request was finished
* @mask: current path mask
* @retries: current number of retries
* @drc: delayed return code
* @cancel: non-zero if request was cancelled
* @done: non-zero if request was finished
*/
struct ccw_request {
struct ccw1 *cp;
@ -108,12 +109,13 @@ struct ccw_request {
enum io_status);
void (*callback)(struct ccw_device *, void *, int);
void *data;
unsigned int singlepath:1;
/* These fields are used internally. */
unsigned int cancel:1;
unsigned int done:1;
u16 mask;
u16 retries;
int drc;
int cancel:1;
int done:1;
} __attribute__((packed));
/*