"lockdep: Fix backtraces" reveales a bug in early setup code: when
lockdep tries to save a stack backtrace before setup_arch has been
called the lowcore pointer for the current thread info pointer isn't
initialized yet.
However our save stack backtrace code relies on it. If the pointer
isn't initialized the saved backtrace will have zero entries.
lockdep however relies (correctly) on the fact that that cannot
happen.
A write access to some random memory region is the result.

Fix this by initializing the thread info pointer early.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Suzuki Poulose reported the following recursive locking bug on s390:

Here is the stack trace : (see Appendix I for more info)

  [<0000000000406ed6>] _spin_lock+0x52/0x94
  [<0000000000103bde>] crst_table_free+0x14e/0x1a4
  [<00000000001ba684>] __pmd_alloc+0x114/0x1ec
  [<00000000001be8d0>] handle_mm_fault+0x2cc/0xb80
  [<0000000000407d62>] do_dat_exception+0x2b6/0x3a0
  [<0000000000114f8c>] sysc_return+0x0/0x8
  [<00000200001642b2>] 0x200001642b2

The page_table_lock is already acquired in __pmd_alloc (mm/memory.c) and
it tries to populate the pud/pgd with a new pmd allocated. If another
thread populates it before we get a chance, we free the pmd using
pmd_free().

On s390x, pmd_free(even pud_free ) is #defined to crst_table_free(),
which acquires the page_table_lock to protect the crst_table index updates.

Hence this ends up in a recursive locking of the page_table_lock.

The solution suggested by Dave Hansen is to use a new spin lock in the mmu
context to protect the access to the crst_list and the pgtable_list.
Reported-by: NSuzuki Poulose <suzuki@in.ibm.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use a console_initcall() to initialize the s390 virtio console and
clean up s390 console initialization in setup.c.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix the order of goto labels in tape_generic_online.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>

For printing unsigned integers hypfs uses "%d" in snprintf(). This is wrong.
With this patch "%u" is used instead.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If a named saved system (NSS) cannot be defined or saved, print out an
error message with the return code of the underlying z/VM CP command.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If dev_set_name fails during scanning the AP bus, the reserved memory
has to be freed.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix lock dependency warning.

inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
bash/1442 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&ap_dev->lock){+.?...}, at: [<000003e001280404>] __ap_poll_device+0x40/0x3e8 [ap]
{IN-SOFTIRQ-W} state was registered at:
  [<000000000017f094>] __lock_acquire+0xb78/0x182c
  [<000000000017fe8e>] lock_acquire+0x146/0x178
  [<0000000000549cf2>] _spin_lock+0x5a/0x98
  [<000003e001280404>] __ap_poll_device+0x40/0x3e8 [ap]
  [<000003e001280afe>] ap_poll_all+0xaa/0x1a4 [ap]
  [<000000000014fa82>] tasklet_action+0xfe/0x1f4
  [<0000000000150a56>] __do_softirq+0x116/0x284
  [<0000000000111058>] do_softirq+0xe4/0xe8
  [<00000000001504ba>] irq_exit+0xba/0xd8
  [<00000000003dd04a>] do_IRQ+0x176/0x1fc
  [<000000000011823c>] io_return+0x0/0x8
  [<0000004bfbfd2c0e>] 0x4bfbfd2c0e
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently in the suspend process checksums for the XPRAM partitions are
created and stored. During the resume process it is checked,
if the checksums are still the same. If this is not the case, a kernel panic
is triggered. Unfortunately this prevents XPRAM from beeing used as suspend
device, because in this case after the checksum has been created, the
memory image is written to XPRAM and therefore the contents of the suspend
partition is changed. In order to allow XPRAM to be used as suspend device,
this patch removes the checksum validation.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The vmur class is allocated after the CCW driver is registered
and it is destroyed before the CCW driver is unregistered.
This is not the correct sequence, because the vmur class can be used
via driver core callbacks that are triggered during the CCW driver
deregistration. For Example:

1. vmur device is online
2. vmur module is unloaded

This leads to the following function call stack:

    <4> [<0000000000387286>] device_destroy+0x36/0x5c
    <4> [<000003e000209714>] ur_set_offline_force+0x9c/0x10c [vmur]
    <4> [<000003e00020a928>] ur_remove+0x64/0xbc [vmur]
    <4> [<00000000003e4d2e>] ccw_device_remove+0x42/0x1ac
    <4> [<000000000038a1aa>] __device_release_driver+0x9a/0xe4
    <4> [<000000000038a2da>] driver_detach+0xe6/0xec
    <4> [<0000000000388ee4>] bus_remove_driver+0xc0/0x108
    <4> [<000003e00020ad5a>] ur_exit+0x52/0x84 [vmur]

In device_destroy() the vmur class is used. Since it is already freed,
this can lead to a kernel panic.

To fix the problem, the vmur class has to be allocated before the CCW
driver is registered and destroyed after the CCW driver has ben unregistered.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Local variable 'qname' in the function hypfs_create_file() really is not
used for any purpose.
Signed-off-by: NVitaliy Gusev <vgusev@openvz.org>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHans-Joachim Picht <hans@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

No need to defined a irq_cpustat_t type if __ARCH_IRQ_STAT is defined.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Eleminate the local variable machine_flags and always change machine
flags directly in the lowcore.
This avoids confusion about when and why the two variables have to be
synchronized.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Note that this patch moves .data.init_task inside _edata.  In
addition, the alignment of .init.ramfs changes: It is now PAGE_ALIGNED
and __initramfs_end is arbitrarily aligned; Previously it was
only aligned to a 0x100-byte boundary, and always ended on an even
byte.

This change results in fewer output sections and in some data being
reordered, but should have no functional effect.
Signed-off-by: NNelson Elhage <nelhage@ksplice.com>
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

.data.page_aligned should not need a separate output section, so as
part of this cleanup I moved into the .data output section in the
linker scripts in order to eliminate unnecessary references to the
section name.

Remove the reference to .data.idt, since nothing is put into the
.data.idt section on the s390 architecture.  It looks like Cyrill
Gorcunov posted a patch to remove the .data.idt code on s390
previously:

<http://lkml.indiana.edu/hypermail/linux/kernel/0802.2/2536.html>

CCing him and the people who acked that patch in case there's a reason
it wasn't applied.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The sysc_restore_trace_psw and io_restore_trace_psw storage locations
are created in the .text section. When creating and IPLing from a named
saved system (NSS), writing to these locations causes a protection exception
(because the .text section is mapped as shared read-only in the NSS).

To permit write access, move the storage locations into the .data section.

The problem occurs only when CONFIG_TRACE_IRQFLAGS is set.
The git commmit that has introduced these variables is:
411788eaSigned-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If the CP SET LOADDEV on the 3215 console has been used to specify
SCPdata, all data is converted to upper case letters.

When scpdata contains upper case letters only, convert all letters
to lower case.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Append scpdata to the kernel boot command line. If scpdata starts
with the equal sign (=), the kernel boot command line is replaced.
(For consistency with zIPL and IPL PARM parameters.)

To use scpdata for the kernel boot command line, scpdata must consist
of ascii characters only. If scpdata contains other characters,
scpdata is not appended to the kernel boot command line.
In addition, re-IPL is extended for setting scpdata for the next
Linux reboot.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With CONFIG_DEBUG_OBJECTS_TIMERS=y "chccwdev --online" for a tape device
will fail with message "ODEBUG: object is on stack, but not annotated".
We now use init_timer_on_stack.
Signed-off-by: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Don't use kfree directly after device registration started.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Merge the nearly empty C files and move everything from power/ to
kernel/. That way the files are easier to handle.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is no caller of do_after_copyback() anywhere. Remove it.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Couple of coding style fixes, replace __inline__ with inline and
remove #ifdef __KERNEL_- since the header file isn't exported.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use compare double and swap to implement efficient atomic64 ops for 31 bit.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move the 64 bit mount code from mcount.S into mcount64.S and avoid
code duplication.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In the meantime gcc generates better code than the old inline
assemblies do. Original inline assembly results in:

lr	%r1,%r2
sr	%r3,%r3
lr	%r2,%r1
srdl	%r2,16
alr	%r2,%r3
alr	%r1,%r2
srl	%r1,16
xilf	%r1,65535
llghr	%r2,%r1
br	%r14

Out of the C code gcc generates this:

rll	%r1,%r2,16
ar	%r1,%r2
srl	%r1,16
xilf	%r1,65535
llghr	%r2,%r1
br	%r14

In addition we don't have any static register allocations anymore and
gcc is free to shuffle instructions around for better pipeline usage.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Introduce get_clock_monotonic() function which can be used to get a
(fast) timestamp. Resolution is the same as for get_clock(). The
only difference is that the timestamps are monotonic and don't jump
backward or forward.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch fixes message naming so that generic dasd messages do not
contain the device discipline. For this purpose the dev_ makros are
replaced by pr_ makros for generic dasd messages.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

remove unnecessary dbf call, remove string operations for magic
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

A DASD device that is not ready or online has no defined disk layout,
so all requests that arrive in such a state need to be returned as
failed.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We used the init_name to set the console ccw_device's name early
at the boot stage. This patch moves the name setting (for all ccw
devices) to the point where we actually register the device. At this
time we can do dynamic allocations and therefore use dev_set_name.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We use a test_and_clear_bit to prevent a device from being
unregistered twice. Unfortunately in this cases the "final"
put_device (from device_initialize) was issued more than once,
resulting in an use after free error. Fix this by moving this
put_device to ccw_device_unregister.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We used the init_name to set the console subchannels name early
at the boot stage. With the patch cio: fix memleak in subchannel validation
we moved the name setting to the point where we actually register the
console subchannel. At this time we can do dynamic allocations and therefore
use dev_set_name.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When scanning for new subchannels we have a code path where we allocate
memory for a struct subchannel, set the device name (which is dynamically
allocated now) and do a check if the underlying device is blacklisted - if
so we free the subchannel structure.
Since we have not set up refcounting at this stage, the device name's memory
is lost. Fix this by moving the dev_set_name after the blacklist test.

Note: With this patch the init_name for the console subchannel becomes
virtually obsolete.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When using s390dbf with "%s" in sprintf format strings the string itself
is not copied to the dbf buffer.
Since in this case only pointers are stored in the s390dbf, we should
not use dev_name - which is bound to the lifetime of the device.
Reading this entry from s390dbf after the device was released will cause
an use after free error.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The number of qdio debugfs entries was limited. Remove this limit
and group the queue files in a per device directory.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When unit checks trigger sensing the device state is set to W4SENSE
until sense completion; then the device state is set back to
ONLINE. If a unit check occurs while set online or set offline
requests are processed then it might happen that the device's
temporary W4SENSE state causes these functions to terminate,
leaving the device in an inconsistent state when the state is set
back to ONLINE later on so that the device cannot be set online or
offline any longer.
To solve this, set online/offline and related rollback or error
routines are processed only if the device is in a final or
DISCONNECTED state.
Signed-off-by: NMichael Ernst <mernst@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ensure to always hold an extra device reference for scheduling a
subchannel deregistration, by moving the get_device to
ccw_device_schedule_sch_unregister. This fixes an use after free
error in ccw_device_call_sch_unregister where put_device was called
on an already freed device structure.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With commit c38f9608 polling was
stopped for the queue even if new data is available.

Return immediately after scheduling the queue tasklet if the queue
is not done.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>