The 3215 console irq handler used to schedule a tasklet. However the
console irq handler also gets called from the infamous cio_tpi()
function. Which in turn does something like

local_bh_disable()
[call console irq handler]
_local_bh_enable()

_local_bh_enable() prevents execution of softirqs, which is intended
within cio_tpi(). However there might be a new softirq pending because
irq handler scheduled a tasklet.
In order to prevent this behaviour we just get rid of the tasklet.
It's not doing much anyway.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The s390 console drivers use the unblank callback of the console
structure to flush the console buffer. In case of a panic or a
reboot the CPU doing the callback can block on the console i/o.
The other CPUs in the system continue to work. For panic this is
not a good idea.

Replace the unblank callback with proper panic/reboot notifier.
These get called after all but one CPU have been stopped.
Signed-off-by: NHolger Smolinski <Holger.Smolinski@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Some further bus_id -> dev_name() conversions in s390 code.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Convert most s390 users setting bus_id to dev_set_name().
css and ccw busses are deferred since they need some special
treatment.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

bus_id -> dev_name() conversions in s390 code.

[cornelia.huck@de.ibm.com: minor adaptions]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In case of error, functions dasd_kmalloc_request and idal_buffer_alloc
return an ERR pointer, but never return the NULL pointer. So after a
call to one of these functions, a NULL test should be replaced by an
IS_ERR test.

A simplified version of the semantic patch that makes this change is
as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@correct_null_test@
expression x,E;
statement S1, S2;
@@
x =
(
  dasd_kmalloc_request(...)
|
  idal_buffer_alloc(...)
)
<... when != x = E
if (
(
- x@p2 != NULL
+ ! IS_ERR ( x )
|
- x@p2 == NULL
+ IS_ERR( x )
)
 )
S1
else S2
...>
? x = E;
// </smpl>
Signed-off-by: NJulien Brunel <brunel@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Since git commit 3da1c84c
"workqueues: make get_online_cpus() useable for work->func()"
it is safe to call get_online_cpus() from workqueue context.
So remove the kthread workaround again.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch enables memory hot-remove on s390.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

sclp_sync_wait wait synchronously for an sclp interrupt and disables
timer interrupts. However on the irq enter paths there is an extra
check if a timer interrupt would be due and calls the timer callback.
This would schedule softirqs in the wrong context.
So introduce local_tick_enable/disable which prevents this.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use -EOPNOTSUPP instead of -ENOTSUPP.
Signed-off-by: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

The kernel part of zfcpdump establishes a new debugfs file zcore/memmap
which exports information on memory layout (start address and length of each
memory chunk) to its userspace counterpart.
Signed-off-by: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

Finally fixes a possible scheduling while in atomic context bug. The driver
used to wait on a waitqueue if no empty buffer was available. This could
lead to a deadlock if the driver was called from non-schedulable context.
So fix this. The write operation may fail now. It returns the number of
characters accepted. put_char will never fail, since it writes characters
to an intermediate buffer which gets flushed as soon as it is full.
That means the driver now can busy wait if something is in the intermediate
buffer and a write_string operation follows. Seems to be an acceptable
compromise, since that shouldn't happen too often.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

After all we came to the conclusion that this interface doesn't make any
sense. Besides that the ioctl number used was never registered, the header
file isn't exported, and we doubt there is even a single user.
So remove this interface, since it eases maintenance.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

Most likely it is broken anyway because of the changes in memory
detection. Since we can't test it and there are probably better ways
that using a P390 card, remove support for it.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

The message descriptions are still missing though ..
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Move memory detection code to own file and also simplify it.
Also add an interface which can be called at any time to get the
current memory layout. This interface is needed by our kernel
internal system dumper.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Cc: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As noted by Akinobu Mita in patch b1fceac2,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

 drivers/s390/char/raw3270.c  |   11 +----------
 drivers/s390/char/sclp_con.c |    2 --
 2 files changed, 1 insertion(+), 12 deletions(-)

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- memset(E,0,E1);
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix a number of sclp_vt220 cleanup problems:
* fix list_empty check after list_del()
* mark init-only flag as __initdata
* remove implicit dependency between slab_available() and num_pages
* straighten multiple init handling (use init count)
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Extend the scsw data structure to the format required by fcx. Also
provide helper functions for easier access to fields which are present
in both the traditional as well as the modified format.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

smp_rescan_cpus() calls get_online_cpus() from a multithreaded
workqueue context. This may deadlock. This is the same bug as in
arch/s390/kernel/topology.c. This patch can be reverted as soon as
Oleg's patch gets merged.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In case the supported sclp facilities change
the new mask should be saved.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Mutex locks are used to avoid problems when /sys/firmware/cpi data
are accessed to in parallel.
Signed-off-by: NMichael Ernst <mernst@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

[jmc: added <linux/smp_lock.h>]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

@r exists@
expression E,E1;
statement S;
position p1,p2,p3;
@@

E =@p1 \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != E = E1
if (E == NULL || ...) S
... when != E = E1
if@p2 (...) {
 ... when != kfree(E)
 }
... when != E = E1
kfree@p3(E);

@forall@
position r.p2;
expression r.E;
int E1 != 0;
@@

* if@p2 (...) {
 ... when != kfree(E)
     when strict
return E1; }
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch fixes a null pointer dereference during initialisation when no
sclp event facility is available:
sclp vt220 tty driver: could not register vt220 - sclp_register returned -5
Unable to handle kernel paging request at virtual user address 0000000000000000
Oops: 0004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 Not tainted 2.6.26-rc3-kvm-bigiron-00968-gd939e93-dirty #30
Process swapper (pid: 0, task: 0000000000600be0, ksp: 000000000064a000)
Krnl PSW : 0400000180000000 0000000000320d8c (sclp_unregister+0x48/0x8c)
           R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000000 0000000000630478 0700000000649c20
           0000000000000000 0000000000433060 000000000064a660 0000000002e26000
           00000000006db000 0000000000000000 0000000000a78578 0000000000649b80
           0000000000630dc0 000000000044fa20 0000000000320d76 0000000000649b80
Krnl Code: 0000000000320d7c: e310c0080004       lg      %r1,8(%r12)
           0000000000320d82: b9040032           lgr     %r3,%r2
           0000000000320d86: c02000187b79       larl    %r2,630478
          >0000000000320d8c: e34010000024       stg     %r4,0(%r1)
           0000000000320d92: e31040080024       stg     %r1,8(%r4)
           0000000000320d98: c01100200200       lgfi    %r1,2097664
           0000000000320d9e: e310c0080024       stg     %r1,8(%r12)
           0000000000320da4: c01100100100       lgfi    %r1,1048832
Call Trace:
([<0000000000320d76>] sclp_unregister+0x32/0x8c)
 [<00000000006657b4>] __sclp_vt220_cleanup+0xc4/0xe0
 [<000000000066595c>] __sclp_vt220_init+0x18c/0x1a0
 [<0000000000665aba>] sclp_vt220_con_init+0x42/0x68
 [<00000000006601ca>] console_init+0x4e/0x68
 [<000000000064acae>] start_kernel+0x3a2/0x4dc
 [<0000000000100020>] _stext+0x20/0x80
INFO: lockdep is turned off.
Last Breaking-Event-Address:
 [<000000000041f964>] _spin_lock_irqsave+0xb0/0xb4
 <4>---[ end trace 31fd0ba7d8756001 ]---

The issue is caused by a list_empty() check in __sclp_vt220_cleanup, which
usually fails on non-initialized list heads that contain {NULL,NULL} instead.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Replace the stack local wait_queue_head_t in tape_do_io and
tape_do_io_interruptible with a per device wait queue.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>