litmus-rt.git/drivers/s390/cio, branch linux-tip

[S390] qdio: free indicator after reset is finished

2010-11-25T08:52:59+00:00

The qdio device indicator is freed before the device is notified that
the indicator is reset. This sequence contains a race when the freed
indicator is used by a new device while the reset of the indicator is
still pending. Do the reset operation before freeing the indicator to
avoid that potential race.

Signed-off-by: Jan Glauber 
Signed-off-by: Martin Schwidefsky

[S390] cio: fix incorrect ccw_device_init_count

2010-11-10T09:05:54+00:00

If device recognition is interrupted by a subchannel event
indicating that the device is gone, ccw_device_init_count
is not correctly decreased.

Fix this by reporting the corresponding event to the device
recognition callback via the state machine.

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

[S390] cio: fix I/O cancel function

2010-10-25T14:10:20+00:00

Function ccw_device_cancel_halt_clear may cause an unexpected kernel
panic if a clear function is currently active at the subchannel for
which it is called. In that case, the iretry counter used to determine
the number of retries is never initialized, leading to an immediate
failure of the function which results in a kernel panic.

Fix this by initializing the iretry counter when the function is
first called. Also replace the kernel panic with a return code: a
single malfunctioning I/O device should not automatically cause a
system-wide kernel panic.

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

[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] css: update subchannel description after hibernate

2010-10-25T14:10:18+00:00

Update the subchannel descriptor while resuming from hibernate
in order to obtain current link addresses.

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

[S390] css: update descriptor after hibernate

2010-10-25T14:10:18+00:00

Update the channel path descriptors after hibernation.
This is done unlocked, since we are the only active
task at this time.

Note: chsc_determine_base_channel_path_desc is changed
to use spin_lock_irqsave, since it's called with
interrupts disabled in this case.

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

[S390] cio: update descriptor in chsc_chp_vary

2010-10-25T14:10:18+00:00

Update the channel path descriptor at the beginning of to the
vary_on operation.

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

[S390] chsc: use the global page to determine the chp desriptor

2010-10-25T14:10:18+00:00

chsc_determine_channel_path_desc is called by a wrapper
who allocates a response struct. The response data
is then memcpy'ed to this response struct by
chsc_determine_channel_path_desc.

Change chsc_determine_base_channel_path_desc to use the
global chsc_page and deliver it to the function doing
the actual chsc call. The channel path desriptor is
then directly read from the response data.

As a result we get rid of the additional allocation
for the response struct.

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

[S390] chsc: consolidate memory allocations

2010-10-25T14:10:18+00:00

Most wrappers around the channel subsystem call have their own logic
to allocate memory (with proper alignment) or use preallocated or
static memory. This patch converts most users of the channel
subsystem call to use the same preallocated page (proteced by a
spinlock).

Note: The sei_page which is used in our crw handler to call
"store event information" has to coexist, since
a) in crw context, while accessing the sei_page, sleeping is allowed
   (which will conflict with the spinlock protection of the chsc_page)
b) in crw context, while accessing the sei_page, channel subsystem
   calls are allowed (which itself would require the page).

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

[S390] chsc: initialization fixes

2010-10-25T14:10:18+00:00

This patch fixes:
 * kfree vs. free_page usage
 * structure definition for determine_css_characteristics
 * naming convention for the chsc init function
 * deregistration of crw handlers in the cleanup path

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