Currently zfpcdump can only collect registers for up to CONFIG_NR_CPUS
CPUss. This dependency is not necessary. So remove it by dynamically
allocating the save area array.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Steven Rostedt noted that s390 is the only architecture which calls
ftrace_push_return_trace() before ftrace_graph_entry() and therefore has
the small advantage that trace.depth gets initialized automatically.

However this small advantage isn't worth the difference and possible subtle
breakage that may result from this.
So change s390 to have the same function call order like all other
architectures: first ftrace_graph_entry(), then ftrace_push_return_trace()
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of this compile warning:

arch/s390/kernel/crash_dump.c: In function 'copy_from_realmem':
arch/s390/kernel/crash_dump.c:48:6: warning: unused variable 'rc'
[-Wunused-variable]
  int rc;
      ^
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The type of 'v->counter' is always 'int', and related inline assembly
code also process 'int', so use 'unsigned int' instead of 'unsigned
long' for the 'mask'.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

If [__]get_user_pages_fast() gets called with nr_pages == 0, the current
code would walk the page tables and pin as many pages until the first
invalid pte (or the kernel crashed while writing struct page pointers to
the pages array).
So let's handle at least the nr_pages == 0 case correctly and exit early.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Just call __get_user_pages_fast() from get_user_pages_fast() like powerpc.
This saves a lot of duplicated code.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

With dirty and referenced bits implemented in software it is unnecessary
to initialize the storage key for every page. With this patch not a single
storage key operation is done for a system that does not use KVM.
For KVM set_pte_at/pgste_set_key will do the initialization for the guest
view of the storage key when the mapping for the page is established in
the host.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The prolog of functions generated by the bpf jit compiler uses an
instruction sequence with an "ahi" instruction to create stack space
instead of using an "aghi" instruction. Using the 32-bit "ahi" is not
wrong as the stack we are operating on is an order-4 allocation which
is always aligned to 16KB. But it is more consistent to use an "aghi"
as the stack pointer is a 64-bit value.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

- turn some macros into functions
- merge two almost identical versions for 32/64 bit
- add BUILD_BUG_ON() check to make sure the passed in array is large enough
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

When quiescing an eadm subchannel make sure that outstanding IO is
cleared and potential timeout handlers are canceled.
Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Implement architecture-specific functionality when a PCI device is
doing a hibernate transition.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Simplify the uaccess code by removing the user_mode=home option.
The kernel will now always run in the home space mode.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

find_first_bit_left() and friends have nothing to do with the normal
LSB0 bit numbering for big endian machines used in Linux (least
significant bit has bit number 0).
Instead they use MSB0 bit numbering, where the most signficant bit has
bit number 0. So rename find_first_bit_left() and friends to
find_first_bit_inv(), to avoid any confusion.
Also provide inv versions of set_bit, clear_bit and test_bit.

This also removes the confusing use of e.g. set_bit() in airq.c which
uses a "be_to_le" bit number conversion, which could imply that instead
set_bit_le() could be used. But that is entirely wrong since the _le
bitops variant uses yet another bit numbering scheme.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Since z9 109 we have the flogr instruction which can be used to implement
optimized versions of __ffs, ffs, __fls, fls and fls64.
So implement and use them, instead of the generic variants.
This reduces the size of the kernel image (defconfig, -march=z9-109)
by 19,648 bytes.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Just like all other architectures we should use out-of-line find bit
operations, since the inline variant bloat the size of the kernel image.
And also like all other architecures we should only supply optimized
variants of the __ffs, ffs, etc. primitives.

Therefore this patch removes the inlined s390 find bit functions and uses
the generic out-of-line variants instead.

The optimization of the primitives follows with the next patch.

With this patch also the functions find_first_bit_left() and
find_next_bit_left() have been reimplemented, since logically, they are
nothing else but a find_first_bit()/find_next_bit() implementation that
use an inverted __fls() instead of __ffs().
Also the restriction that these functions only work on machines which
support the "flogr" instruction is gone now.

This reduces the size of the kernel image (defconfig, -march=z9-109)
by 144,482 bytes.
Alone the size of the function build_sched_domains() gets reduced from
7 KB to 3,5 KB.

We also git rid of unused functions like find_first_bit_le()...
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Refactor direct debug level comparisons with the (internal) s390db->level
member.  Use the debug_level_enabled() function instead.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Add the debug_level_enabled() function to check if debug events for
a particular level would be logged.  This might help to save cycles
for debug events that require additional information collection.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Since zEC12 we have the interlocked-access facility 2 which allows to
use the instructions ni/oi/xi to update a single byte in storage with
compare-and-swap semantics.
So change set_bit(), clear_bit() and change_bit() to generate such code
instead of a compare-and-swap loop (or using the load-and-* instruction
family), if possible.
This reduces the text segment by yet another 8KB (defconfig).

Alternatively the long displacement variants niy/oiy/xiy could have
been used, but the extended displacement field is usually not needed
and therefore would only increase the size of the text segment again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Remove CONFIG_SMP from bitops code. This reduces the C code significantly
but also generates better code for the SMP case.

This means that for !CONFIG_SMP set_bit() and friends now also have
compare and swap semantics (read: more code). However nobody really cares
for !CONFIG_SMP and this is the trade-off to simplify the SMP code which we
do care about.

The non-atomic bitops like __set_bit() now generate also better code
because the old code did not have a __builtin_contant_p() check for the
CONFIG_SMP case and therefore always generated the inline assembly variant.
However the inline assemblies for the non-atomic case now got completely
removed since gcc can produce better code, which accesses less memory
operands.

test_bit() got also a bit simplified since it did have a
__builtin_constant_p() check, however two identical code pathes for each
case (written differently).

In result this mainly reduces the to be maintained code but is not very
relevant for code generation, since there are not many non-atomic bitops
usages that we care about.
(code reduction defconfig kernel image before/after: 560 bytes).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

- add a typecheck to the defines to make sure they operate on an atomic_t
- simplify inline assembly constraints
- keep variable names common between functions
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

If the interlocked-access facility 1 is available we can use the asi
and agsi instructions for interlocked updates if the to be added
value is a contanst and small (in the range of -128..127).
asi and agsi do not not return the old or new value, therefore these
instructions can only be used for atomic_(add|sub|inc|dec)[64].
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

get_inbound_buffer_frontier() makes use of the return value of atomic_sub()
which shouldn't work, since atomic_sub() is supposed to return void.
This only works on s390 because atomic_sub() gets mapped to atomic_sub_return()
with a define without changing it's return value to void.

So use atomic_sub_return() instead of atomic_sub() in qeth code before fixing
atomic ops.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Since we have an in-kernel disassembler we can make sure that
there won't be any kprobes set on random data.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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

Now that the in-kernel disassembler has an own header file move the
disassembler related function prototypes to that header file.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The patch moves some of the definitions to a
header file. No functional changes involved.

I have retained the Copyright Statement from the
original file.
Signed-off-by: Suzuki K Poulose <suzuki@in.ibm.com>
[Heiko Carstens: rename s390-dis.h to dis.h]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Rename 'insn' and 'operand' structures to more canonical names
to avoid conflicts.

struct insn represents information about an instruction, including
the mnemonics, format and opcode.

struct operand represents the 'properties' and information on howto
interpret the operand value and doesn't contain the value.

We rename these structures for avoiding a global conflict.

i.e,

1,$s/struct insn/struct s390_insn/g
1,$s/struct operand/struct s390_operand/g
Signed-off-by: Suzuki K Poulose <suzuki@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Same as for bitops: make use of the interlocked-access facility 1
instructions which allow to atomically update storage locations
without a compare-and-swap loop.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of the own atomic_sub_return() implementation. Otherwise we can't
make use of the interlocked-access facility 1 instructions for
atomic_sub_return(), since there is no "load and subtract" instruction
available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

When checking the insn address wether it is a kernel image or module
address it should be an if-else-if statement not two independent if
statements.
This doesn't really fix a bug, but matches s390_free_insn_slot().
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Currently we only set the -march compiler option if the kbuild
system figured out that the compiler actually supports the selected
architecture (cc-option test).

In result this means that no -march compiler option is set when an
unsupported cpu architecture of the current compiler is selected.
The kernel compile will afterwards succeed but with the default
architecture instead of the (unsupported) selected one.

Change this behaviour, so compiles will fail if the compiler does
not support the selected cpu architecture.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Make use of the interlocked-access facility 1 that got added with the
z196 architecure.
This facilility added new instructions which can atomically update a
storage location without a compare-and-swap loop. E.g. setting a bit
within a "long" can be done with a single instruction.

The size of the kernel image gets ~30kb smaller. Considering that there
are appr. 1900 bitops call sites this means that each one saves about
15-16 bytes per call site which is expected.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Pull md bugfixes from Neil Brown:
 "Assorted md bug-fixes for 3.12.

  All tagged for -stable releases too"

* tag 'md/3.12-fixes' of git://neil.brown.name/md:
  raid5: avoid finding "discard" stripe
  raid5: set bio bi_vcnt 0 for discard request
  md: avoid deadlock when md_set_badblocks.
  md: Fix skipping recovery for read-only arrays.

Pull SCSI fixes from James Bottomley:
 "This is a set of two fixes which cause oopses (Buslogic, qla2xxx) and
 one fix which may cause a hang because of request miscounting (sd)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] sd: call blk_pm_runtime_init before add_disk
  [SCSI] qla2xxx: Fix request queue null dereference.
  [SCSI] BusLogic: Fix an oops when intializing multimaster adapter

SCSI discard will damage discard stripe bio setting, eg, some fields are
changed. If the stripe is reused very soon, we have wrong bios setting. We
remove discard stripe from hash list, so next time the strip will be fully
initialized.

Suitable for backport to 3.7+.

Cc: <stable@vger.kernel.org> (3.7+)
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>

SCSI layer will add new payload for discard request. If two bios are merged
to one, the second bio has bi_vcnt 1 which is set in raid5. This will confuse
SCSI and cause oops.

Suitable for backport to 3.7+

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

When operate harddisk and hit errors, md_set_badblocks is called after
scsi_restart_operations which already disabled the irq. but md_set_badblocks
will call write_sequnlock_irq and enable irq. so softirq can preempt the
current thread and that may cause a deadlock. I think this situation should
use write_sequnlock_irqsave/irqrestore instead.

I met the situation and the call trace is below:
[  638.919974] BUG: spinlock recursion on CPU#0, scsi_eh_13/1010
[  638.921923]  lock: 0xffff8800d4d51fc8, .magic: dead4ead, .owner: scsi_eh_13/1010, .owner_cpu: 0
[  638.923890] CPU: 0 PID: 1010 Comm: scsi_eh_13 Not tainted 3.12.0-rc5+ #37
[  638.925844] Hardware name: To be filled by O.E.M. To be filled by O.E.M./MAHOBAY, BIOS 4.6.5 03/05/2013
[  638.927816]  ffff880037ad4640 ffff880118c03d50 ffffffff8172ff85 0000000000000007
[  638.929829]  ffff8800d4d51fc8 ffff880118c03d70 ffffffff81730030 ffff8800d4d51fc8
[  638.931848]  ffffffff81a72eb0 ffff880118c03d90 ffffffff81730056 ffff8800d4d51fc8
[  638.933884] Call Trace:
[  638.935867]  <IRQ>  [<ffffffff8172ff85>] dump_stack+0x55/0x76
[  638.937878]  [<ffffffff81730030>] spin_dump+0x8a/0x8f
[  638.939861]  [<ffffffff81730056>] spin_bug+0x21/0x26
[  638.941836]  [<ffffffff81336de4>] do_raw_spin_lock+0xa4/0xc0
[  638.943801]  [<ffffffff8173f036>] _raw_spin_lock+0x66/0x80
[  638.945747]  [<ffffffff814a73ed>] ? scsi_device_unbusy+0x9d/0xd0
[  638.947672]  [<ffffffff8173fb1b>] ? _raw_spin_unlock+0x2b/0x50
[  638.949595]  [<ffffffff814a73ed>] scsi_device_unbusy+0x9d/0xd0
[  638.951504]  [<ffffffff8149ec47>] scsi_finish_command+0x37/0xe0
[  638.953388]  [<ffffffff814a75e8>] scsi_softirq_done+0xa8/0x140
[  638.955248]  [<ffffffff8130e32b>] blk_done_softirq+0x7b/0x90
[  638.957116]  [<ffffffff8104fddd>] __do_softirq+0xfd/0x330
[  638.958987]  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.960861]  [<ffffffff8174a5cc>] call_softirq+0x1c/0x30
[  638.962724]  [<ffffffff81004c7d>] do_softirq+0x8d/0xc0
[  638.964565]  [<ffffffff8105024e>] irq_exit+0x10e/0x150
[  638.966390]  [<ffffffff8174ad4a>] smp_apic_timer_interrupt+0x4a/0x60
[  638.968223]  [<ffffffff817499af>] apic_timer_interrupt+0x6f/0x80
[  638.970079]  <EOI>  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.971899]  [<ffffffff8173fa6a>] ? _raw_spin_unlock_irq+0x3a/0x50
[  638.973691]  [<ffffffff8173fa60>] ? _raw_spin_unlock_irq+0x30/0x50
[  638.975475]  [<ffffffff81562393>] md_set_badblocks+0x1f3/0x4a0
[  638.977243]  [<ffffffff81566e07>] rdev_set_badblocks+0x27/0x80
[  638.978988]  [<ffffffffa00d97bb>] raid5_end_read_request+0x36b/0x4e0 [raid456]
[  638.980723]  [<ffffffff811b5a1d>] bio_endio+0x1d/0x40
[  638.982463]  [<ffffffff81304ff3>] req_bio_endio.isra.65+0x83/0xa0
[  638.984214]  [<ffffffff81306b9f>] blk_update_request+0x7f/0x350
[  638.985967]  [<ffffffff81306ea1>] blk_update_bidi_request+0x31/0x90
[  638.987710]  [<ffffffff813085e0>] __blk_end_bidi_request+0x20/0x50
[  638.989439]  [<ffffffff8130862f>] __blk_end_request_all+0x1f/0x30
[  638.991149]  [<ffffffff81308746>] blk_peek_request+0x106/0x250
[  638.992861]  [<ffffffff814a62a9>] ? scsi_kill_request.isra.32+0xe9/0x130
[  638.994561]  [<ffffffff814a633a>] scsi_request_fn+0x4a/0x3d0
[  638.996251]  [<ffffffff813040a7>] __blk_run_queue+0x37/0x50
[  638.997900]  [<ffffffff813045af>] blk_run_queue+0x2f/0x50
[  638.999553]  [<ffffffff814a5750>] scsi_run_queue+0xe0/0x1c0
[  639.001185]  [<ffffffff814a7721>] scsi_run_host_queues+0x21/0x40
[  639.002798]  [<ffffffff814a2e87>] scsi_restart_operations+0x177/0x200
[  639.004391]  [<ffffffff814a4fe9>] scsi_error_handler+0xc9/0xe0
[  639.005996]  [<ffffffff814a4f20>] ? scsi_unjam_host+0xd0/0xd0
[  639.007600]  [<ffffffff81072f6b>] kthread+0xdb/0xe0
[  639.009205]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
[  639.010821]  [<ffffffff81748cac>] ret_from_fork+0x7c/0xb0
[  639.012437]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170

This bug was introduce in commit  2e8ac303
(the first time rdev_set_badblock was call from interrupt context),
so this patch is appropriate for 3.5 and subsequent kernels.

Cc: <stable@vger.kernel.org> (3.5+)
Signed-off-by: Bian Yu <bianyu@kedacom.com>
Reviewed-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

Since:
        commit 7ceb17e8
        md: Allow devices to be re-added to a read-only array.

spares are activated on a read-only array. In case of raid1 and raid10
personalities it causes that not-in-sync devices are marked in-sync
without checking if recovery has been finished.

If a read-only array is degraded and one of its devices is not in-sync
(because the array has been only partially recovered) recovery will be skipped.

This patch adds checking if recovery has been finished before marking a device
in-sync for raid1 and raid10 personalities. In case of raid5 personality
such condition is already present (at raid5.c:6029).

Bug was introduced in 3.10 and causes data corruption.

Cc: stable@vger.kernel.org
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

Sujit has found a race condition that would make q->nr_pending
unbalanced, it occurs as Sujit explained:

"
sd_probe_async() ->
	add_disk() ->
		disk_add_event() ->
			schedule(disk_events_workfn)
	sd_revalidate_disk()
	blk_pm_runtime_init()
return;

Let's say the disk_events_workfn() calls sd_check_events() which tries
to send test_unit_ready() and because of sd_revalidate_disk() trying to
send another commands the test_unit_ready() might be re-queued as the
tagged command queuing is disabled.

So the race condition is -

Thread 1 			  |		Thread 2
sd_revalidate_disk()		  |	sd_check_events()
...nr_pending = 0 as q->dev = NULL|	scsi_queue_insert()
blk_runtime_pm_init()		  | 	blk_pm_requeue_request() ->
				  |	nr_pending = -1 since
				  |	q->dev != NULL
"

The problem is, the test_unit_ready request doesn't get counted the
first time it is queued, so the later decrement of q->nr_pending in
blk_pm_requeue_request makes it unbalanced.

Fix this by calling blk_pm_runtime_init before add_disk so that all
requests initiated there will all be counted.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reported-and-tested-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

If an invalid IOCB is returned on the response queue then the index into the
request queue map could be invalid and could return to us a bogus value. This
could cause us to try to deference an invalid pointer and cause an exception.

If we encounter this condition, simply return as no context can be established
for this response.
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>