linux-toradex.git/drivers/s390/cio/device_pgid.c, branch v3.4.1

[S390] cio: notify drivers of channel path events

2010-10-25T14:10:19+00:00

This patch adds a notification mechanism to inform ccw drivers
about changes to channel paths, which occured while the device
is online.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

[S390] cio: use all available paths for some internal I/O

2010-08-09T16:12:54+00:00

Use all available paths for the SENSE ID and STLCK commands. This
prevents deadlocks in conjunction with reserved devices.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

[S390] ccwreq: add ability to use all paths

2010-08-09T16:12:54+00:00

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 
Signed-off-by: Martin Schwidefsky

[S390] cio: fix channel path vary

2009-12-18T16:43:32+00:00

Channel path vary is currently broken: channel paths which are varied
offline are still used by Linux. The reason for this is that:

 * the path mask indicating which paths of an I/O device can be used
   is reset by each internal I/O request
 * the logic that checks if a path group is already in its designated
   target state incorrectly interprets the result "is correctly set"
   as "is correctly set and available"

Fix this by resetting the path mask only for internal I/O requests
which affect the path mask and by correcting the pgid check logic.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: improve error recovery for internal I/Os

2009-12-07T11:51:33+00:00

Improve error recovery for internal I/Os by repeating each I/O
256 times per path to cope with long-running non-permanent error
conditions. Also retry each path twice to cope with link flapping,
i.e. single paths becoming unavailable in the order in which they
are tried.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: make steal lock procedure more robust

2009-12-07T11:51:32+00:00

An Unconditional Reserve + Release operation (steal lock) for a
boxed device may fail when encountering special error cases
(e.g. unit checks or path errors). Fix this by using the more
robust ccw_request infrastructure for performing the steal lock
CCW program.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: use sense-pgid operation for path verification

2009-12-07T11:51:31+00:00

Set-pgid operations fail for some device types under z/VM for which
the hypervisor has already set the pgid. Also reserved devices or
changed pgids are not correctly recognized. Fix these problems by
using a combination of sense-pgid and set-pgid and by also accepting
pre-defined pgid settings.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: split PGID settings and status

2009-12-07T11:51:31+00:00

Split setting (driver wants feature enabled) and status (feature
setup was successful) for PGID related ccw device features so that
setup errors can be detected. Previously, incorrectly handled setup
errors could in rare cases lead to erratic I/O behavior and
permanently unusuable devices.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: use ccw request infrastructure for pgid

2009-12-07T11:51:31+00:00

Use the newly introduced ccw request infrastructure to implement
pgid related operations: sense pgid, set pgid and disband pg.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky

[S390] cio: handle error during path verification consistently

2009-12-07T11:51:30+00:00

Handle verification errors consistently through the existing
callback ccw_device_done to reduce cleanup code duplication.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Martin Schwidefsky