drm/i915: fix DDI PLLs HW state readout code

Properly zero the refcounts and crtc->ddi_pll_set so the previous HW
state doesn't affect the result of reading the current HW state.

This fixes WARNs about WRPLL refcount if we have an HDMI monitor on
HSW and then suspend/resume.

Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64379
Tested-by: Qingshuai Tian <qingshuai.tian@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: Don't grab crtc mutexes in intel_modeset_gem_init()

When the pipe A force quirk is applied the code will attempt to grab
a crtc mutex during intel_modeset_setup_hw_state(). If we're already
holding all crtc mutexes this will obviously deadlock every time.

So instead of using drm_modeset_lock_all() just grab the
mode_config.mutex. This is enough to avoid the unlocked mutex warnings
from certain lower level functions.

The regression was introduced in:

 commit 027476642811f8559cbe00ef6cc54db230e48a20
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Mon Dec 2 11:08:06 2013 +0200

    drm/i915: Take modeset locks around intel_modeset_setup_hw_state()

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
[danvet: Add cc: stable since the offending commit has that, too.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915/bdw: make sure south port interrupts are enabled properly v2

We were apparently relying on the defaults on BDW, which resulted in no
hotplug or AUX interrupts.  So be sure to call the ibx_irq_preinstall to
enable all interrupts.

v2: use preinstall instead of redundant SDIER write

References: https://bugs.freedesktop.org/show_bug.cgi?id=72834
References: https://bugs.freedesktop.org/show_bug.cgi?id=72833
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Merge tag 'drm-intel-fixes-2014-01-13' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes

Black screen fixes, one for hsw+bdw each and a regression fix for
locking+load detection.

* tag 'drm-intel-fixes-2014-01-13' of git://people.freedesktop.org/~danvet/drm-intel:
  drm/i915/bdw: make sure south port interrupts are enabled properly v2
  drm/i915: Don't grab crtc mutexes in intel_modeset_gem_init()
  drm/i915: fix DDI PLLs HW state readout code
Revert "drm: copy mode type in drm_mode_connector_list_update()"

This reverts commit 3fbd6439e4639ecaeaae6c079e0aa497a1ac3482.

This caused some strange booting lockup issues on an Intel G33
belonging to Daniel Vetter, very unusual, I was hoping Daniel
would track this down, but it looks like instead I'll have to hack
a different fix for -next.

Signed-off-by: Dave Airlie <airlied@redhat.com>
md/raid5: Fix possible confusion when multiple write errors occur.

commit 5d8c71f9e5fbdd95650be00294d238e27a363b5c
    md: raid5 crash during degradation

Fixed a crash in an overly simplistic way which could leave
R5_WriteError or R5_MadeGood set in the stripe cache for devices
for which it is no longer relevant.
When those devices are removed and spares added the flags are still
set and can cause incorrect behaviour.

commit 14a75d3e07c784c004b4b44b34af996b8e4ac453
    md/raid5: preferentially read from replacement device if possible.

Fixed the same bug if a more effective way, so we can now revert
the original commit.

Reported-and-tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Cc: stable@vger.kernel.org (3.2+ - 3.2 will need a different fix though)
Fixes: 5d8c71f9e5fbdd95650be00294d238e27a363b5c
Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: fix two bugs in handling of known-bad-blocks.

If we discover a bad block when reading we split the request and
potentially read some of it from a different device.

The code path of this has two bugs in RAID10.
1/ we get a spin_lock with _irq, but unlock without _irq!!
2/ The calculation of 'sectors_handled' is wrong, as can be clearly
   seen by comparison with raid1.c

This leads to at least 2 warnings and a probable crash is a RAID10
ever had known bad blocks.

Cc: stable@vger.kernel.org (v3.1+)
Fixes: 856e08e23762dfb92ffc68fd0a8d228f9e152160
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
md/raid1: fix request counting bug in new 'barrier' code.

The new iobarrier implementation in raid1 (which keeps normal writes
and resync activity separate) counts every request what is not before
the current resync point in either next_window_requests or
current_window_requests.
It flags that the request is counted by setting ->start_next_window.

allow_barrier follows this model exactly and decrements one of the
*_window_requests if and only if ->start_next_window is set.

However wait_barrier(), which increments *_window_requests uses a
slightly different test for setting -.start_next_window (which is set
from the return value of this function).
So there is a possibility of the counts getting out of sync, and this
leads to the resync hanging.

So change wait_barrier() to return a non-zero value in exactly the
same cases that it increments *_window_requests.

But was introduced in 3.13-rc1.

Reported-by: Bruno Wolff III <bruno@wolff.to>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68061
Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761
Cc: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
md/raid5: fix a recently broken BUG_ON().

commit 6d183de4077191d1201283a9035ce57a9b05254d
    md/raid5: fix newly-broken locking in get_active_stripe.

simplified a BUG_ON, but removed too much so now it sometimes fires
when it shouldn't.

When the STRIPE_EXPANDING flag is set, the stripe_head might be on a
special list while multiple stripe_heads are collected, or it might
not be on any list, even a 'free' list when the refcount is zero.  As
long as STRIPE_EXPANDING is set, it will be found and added back to a
list eventually.

So both of the BUG_ONs which test for the ->lru being empty or not
need to avoid the case where STRIPE_EXPANDING is set.

The patch which broke this was marked for -stable, so this patch needs
to be applied to any branch that received 6d183de4

Fixes: 6d183de4077191d1201283a9035ce57a9b05254d
Cc: stable@vger.kernel.org (any release to which above was applied)
Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: fix bug when raid10 recovery fails to recover a block.

commit e875ecea266a543e643b19e44cf472f1412708f9
    md/raid10 record bad blocks as needed during recovery.

added code to the "cannot recover this block" path to record a bad
block rather than fail the whole recovery.
Unfortunately this new case was placed *after* r10bio was freed rather
than *before*, yet it still uses r10bio.
This is will crash with a null dereference.

So move the freeing of r10bio down where it is safe.

Cc: stable@vger.kernel.org (v3.1+)
Fixes: e875ecea266a543e643b19e44cf472f1412708f9
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
md: fix problem when adding device to read-only array with bitmap.

If an array is started degraded, and then the missing device
is found it can be re-added and a minimal bitmap-based recovery
will bring it fully up-to-date.

If the array is read-only a recovery would not be allowed.
But also if the array is read-only and the missing device was
present very recently, then there could be no need for any
recovery at all, so we simply include the device in the read-only
array without any recovery.

However... if the missing device was removed a little longer ago
it could be missing some updates, but if a bitmap is present it will
be conditionally accepted pending a bitmap-based update.  We don't
currently detect this case properly and will include that old
device into the read-only array with no recovery even though it really
needs a recovery.

This patch keeps track of whether a bitmap-based-recovery is really
needed or not in the new Bitmap_sync rdev flag.  If that is set,
then the device will not be added to a read-only array.

Cc: Andrei Warkentin <andreiw@vmware.com>
Fixes: d70ed2e4fafdbef0800e73942482bb075c21578b
Cc: stable@vger.kernel.org (3.2+)
Signed-off-by: NeilBrown <neilb@suse.de>
drm/nouveau: fix null ptr dereferences on some boards

Regression from "device: populate master subdev pointer only when fully
constructed"

Reported-by: Bob Gleitsmann <rjgleits@bellsouth.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Merge branch 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes

Single regression fix for nouveau

* 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6:
  drm/nouveau: fix null ptr dereferences on some boards
nilfs2: fix segctor bug that causes file system corruption

There is a bug in the function nilfs_segctor_collect, which results in
active data being written to a segment, that is marked as clean.  It is
possible, that this segment is selected for a later segment
construction, whereby the old data is overwritten.

The problem shows itself with the following kernel log message:

  nilfs_sufile_do_cancel_free: segment 6533 must be clean

Usually a few hours later the file system gets corrupted:

  NILFS: bad btree node (blocknr=8748107): level = 0, flags = 0x0, nchildren = 0
  NILFS error (device sdc1): nilfs_bmap_last_key: broken bmap (inode number=114660)

The issue can be reproduced with a file system that is nearly full and
with the cleaner running, while some IO intensive task is running.
Although it is quite hard to reproduce.

This is what happens:

 1. The cleaner starts the segment construction
 2. nilfs_segctor_collect is called
 3. sc_stage is on NILFS_ST_SUFILE and segments are freed
 4. sc_stage is on NILFS_ST_DAT current segment is full
 5. nilfs_segctor_extend_segments is called, which
    allocates a new segment
 6. The new segment is one of the segments freed in step 3
 7. nilfs_sufile_cancel_freev is called and produces an error message
 8. Loop around and the collection starts again
 9. sc_stage is on NILFS_ST_SUFILE and segments are freed
    including the newly allocated segment, which will contain active
    data and can be allocated at a later time
10. A few hours later another segment construction allocates the
    segment and causes file system corruption

This can be prevented by simply reordering the statements.  If
nilfs_sufile_cancel_freev is called before nilfs_segctor_extend_segments
the freed segments are marked as dirty and cannot be allocated any more.

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Reviewed-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MIPS: fix case mismatch in local_r4k_flush_icache_range()

Currently, Loongson-2 call protected_blast_icache_range() and others
call protected_loongson23_blast_icache_range(), but I think the correct
behavior should be the opposite.  BTW, Loongson-3's cache-ops is
compatible with MIPS64, but not compatible with Loongson-2.  So, rename
xxx_loongson23_yyy things to xxx_loongson2_yyy.

The patch fixes early boot hang with 3.13-rc1, introduced in commit
14bd8c082016 ("MIPS: Loongson: Get rid of Loongson 2 #ifdefery all over
arch/mips").

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: John Crispin <blogic@openwrt.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MIPS: fix blast_icache32 on loongson2

Commit 14bd8c082016 ("MIPS: Loongson: Get rid of Loongson 2 #ifdefery
all over arch/mips") failed to add Loongson2 specific blast_icache32
functions.  Fix that.

The patch fixes the following crash seen with 3.13-rc1:

  Reserved instruction in kernel code[#1]:
  [...]
  Call Trace:
    blast_icache32_page+0x8/0xb0
    r4k_flush_cache_page+0x19c/0x200
    do_wp_page.isra.97+0x47c/0xe08
    handle_mm_fault+0x938/0x1118
    __do_page_fault+0x140/0x540
    resume_userspace_check+0x0/0x10
  Code: 00200825  64834000  00200825 <bc900000> bc900020  bc900040  bc900060  bc900080  bc9000a0

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: John Crispin <blogic@openwrt.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: fix crash when using XFS on loopback

Commit 8456a648cf44 ("slab: use struct page for slab management") causes
a crash in the LVM2 testsuite on PA-RISC (the crashing test is
fsadm.sh).  The testsuite doesn't crash on 3.12, crashes on 3.13-rc1 and
later.

 Bad Address (null pointer deref?): Code=15 regs=000000413edd89a0 (Addr=000006202224647d)
 CPU: 3 PID: 24008 Comm: loop0 Not tainted 3.13.0-rc6 #5
 task: 00000001bf3c0048 ti: 000000413edd8000 task.ti: 000000413edd8000

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
 PSW: 00001000000001101111100100001110 Not tainted
 r00-03  000000ff0806f90e 00000000405c8de0 000000004013e6c0 000000413edd83f0
 r04-07  00000000405a95e0 0000000000000200 00000001414735f0 00000001bf349e40
 r08-11  0000000010fe3d10 0000000000000001 00000040829c7778 000000413efd9000
 r12-15  0000000000000000 000000004060d800 0000000010fe3000 0000000010fe3000
 r16-19  000000413edd82a0 00000041078ddbc0 0000000000000010 0000000000000001
 r20-23  0008f3d0d83a8000 0000000000000000 00000040829c7778 0000000000000080
 r24-27  00000001bf349e40 00000001bf349e40 202d66202224640d 00000000405a95e0
 r28-31  202d662022246465 000000413edd88f0 000000413edd89a0 0000000000000001
 sr00-03  000000000532c000 0000000000000000 0000000000000000 000000000532c000
 sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

 IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000401fe42c 00000000401fe430
  IIR: 539c0030    ISR: 00000000202d6000  IOR: 000006202224647d
  CPU:        3   CR30: 000000413edd8000 CR31: 0000000000000000
  ORIG_R28: 00000000405a95e0
  IAOQ[0]: vma_interval_tree_iter_first+0x14/0x48
  IAOQ[1]: vma_interval_tree_iter_first+0x18/0x48
  RP(r2): flush_dcache_page+0x128/0x388
 Backtrace:
   flush_dcache_page+0x128/0x388
   lo_splice_actor+0x90/0x148 [loop]
   splice_from_pipe_feed+0xc0/0x1d0
   __splice_from_pipe+0xac/0xc0
   lo_direct_splice_actor+0x1c/0x70 [loop]
   splice_direct_to_actor+0xec/0x228
   lo_receive+0xe4/0x298 [loop]
   loop_thread+0x478/0x640 [loop]
   kthread+0x134/0x168
   end_fault_vector+0x20/0x28
   xfs_setsize_buftarg+0x0/0x90 [xfs]

 Kernel panic - not syncing: Bad Address (null pointer deref?)

Commit 8456a648cf44 changes the page structure so that the slab
subsystem reuses the page->mapping field.

The crash happens in the following way:
 * XFS allocates some memory from slab and issues a bio to read data
   into it.
 * the bio is sent to the loopback device.
 * lo_receive creates an actor and calls splice_direct_to_actor.
 * lo_splice_actor copies data to the target page.
 * lo_splice_actor calls flush_dcache_page because the page may be
   mapped by userspace.  In that case we need to flush the kernel cache.
 * flush_dcache_page asks for the list of userspace mappings, however
   that page->mapping field is reused by the slab subsystem for a
   different purpose.  This causes the crash.

Note that other architectures without coherent caches (sparc, arm, mips)
also call page_mapping from flush_dcache_page, so they may crash in the
same way.

This patch fixes this bug by testing if the page is a slab page in
page_mapping and returning NULL if it is.

The patch also fixes VM_BUG_ON(PageSlab(page)) that could happen in
earlier kernels in the same scenario on architectures without cache
coherence when CONFIG_DEBUG_VM is enabled - so it should be backported
to stable kernels.

In the old kernels, the function page_mapping is placed in
include/linux/mm.h, so you should modify the patch accordingly when
backporting it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: John David Anglin <dave.anglin@bell.net>]
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
crash_dump: fix compilation error (on MIPS at least)

  In file included from kernel/crash_dump.c:2:0:
  include/linux/crash_dump.h:22:27: error: unknown type name `pgprot_t'

when CONFIG_CRASH_DUMP=y

The error was traced back to commit 9cb218131de1 ("vmcore: introduce
remap_oldmem_pfn_range()")

include <asm/pgtable.h> to get the missing definition

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib/percpu_counter.c: fix __percpu_counter_add()

__percpu_counter_add() may be called in softirq/hardirq handler (such
as, blk_mq_queue_exit() is typically called in hardirq/softirq handler),
so we need to call this_cpu_add()(irq safe helper) to update percpu
counter, otherwise counts may be lost.

This fixes the problem that 'rmmod null_blk' hangs in blk_cleanup_queue()
because of miscounting of request_queue->mq_usage_counter.

This patch is the v1 of previous one of "lib/percpu_counter.c:
disable local irq when updating percpu couter", and takes Andrew's
approach which may be more efficient for ARCHs(x86, s390) that
have optimized this_cpu_add().

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
 "One nouveau regression fix on older cards, i915 black screen fixes,
  and a revert for a strange G33 intel problem"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau: fix null ptr dereferences on some boards
  Revert "drm: copy mode type in drm_mode_connector_list_update()"
  drm/i915/bdw: make sure south port interrupts are enabled properly v2
  drm/i915: Don't grab crtc mutexes in intel_modeset_gem_init()
  drm/i915: fix DDI PLLs HW state readout code