xtensa: fix warning '"CONFIG_OF" is not defined'

The warning only shows up when building MMUv3 configuration with OF
support disabled.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: export ccount_freq

Now that ccount_freq is used in udelay and ndelay it needs to be
exported in order to be available to modules.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: introduce spill_registers_kernel macro

Most in-kernel users want registers spilled on the kernel stack and
don't require PS.EXCM to be set. That means that they don't need fixup
routine and could reuse regular window overflow mechanism for that,
which makes spill routine very simple.

Cc: stable@vger.kernel.org
Suggested-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: save current register frame in fast_syscall_spill_registers_fixup

We need it saved because it contains a3 where we track which register
windows we still need to spill, and fixup handler may call C exception
handlers. Also fix comments.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: fix fast_syscall_spill_registers

The original implementation could clobber registers under certain conditions.

The Xtensa processor architecture uses windowed registers and the original
implementation was using a4 as a temporary register, which under certain
conditions could be register a0 of the oldest window frame, and didn't always
restore the content correctly.

By moving the _spill_registers routine inside the fast system call, it frees
up one more register (the return address is not required anymore) for the
spill routine.

Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: fix fast_syscall_spill_registers

The original implementation could clobber registers under certain conditions.

The Xtensa processor architecture uses windowed registers and the original
implementation was using a4 as a temporary register, which under certain
conditions could be register a0 of the oldest window frame, and didn't always
restore the content correctly.

By moving the _spill_registers routine inside the fast system call, it frees
up one more register (the return address is not required anymore) for the
spill routine.

Signed-off-by: Chris Zankel <chris@zankel.net>
UBI: fix some use after free bugs

Move the kmem_cache_free() calls down a couple lines.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
m68k: Sort arch/m68k/include/asm/Kbuild

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
m68k: Switch to asm-generic/barrier.h

The generic nop() implementation is fine for m68k.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
m68k: Wire up sched_setattr and sched_getattr

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
drm/tegra: fix typo 'CONFIG_TEGRA_DRM_FBDEV'

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Thierry Reding <treding@nvidia.com>
gpu: host1x: do not check previously handled gathers

When patching gathers, we don't need to check against
gathers with lower indices than the current one, as
they are guaranteed to already have been handled.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
drm/tegra: Add guard to avoid double disable/enable of RGB outputs

Add guard to check whether RGB output is already enabled in the way it's
done for HDMI output. Fixes possible hang on trying to disable output twice
(first time during driver probe and second on fb registering).

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
mtd: nand: fix off-by-one read retry mode counting

A flash may support N read retry voltage threshold modes, numbered 0
through N-1 (where mode 0 represents the initial state). However,
nand_do_read_ops() tries to use mode 0 through N.

This off-by-one error shows up, for instance, when using nanddump, and
we have cycled through available modes:

    nand: setting READ RETRY mode 0
    nand: setting READ RETRY mode 1
    nand: setting READ RETRY mode 2
    nand: setting READ RETRY mode 3
    nand: setting READ RETRY mode 4
    nand: setting READ RETRY mode 5
    nand: setting READ RETRY mode 6
    nand: setting READ RETRY mode 7
    nand: setting READ RETRY mode 8
    libmtd: error!: cannot read 8192 bytes from mtd0 (eraseblock 20, offset 0)
            error 22 (Invalid argument)
    nanddump: error!: mtd_read

Tested on Micron MT29F64G08CBCBBH1, with 8 retry modes.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
dma: ste_dma40: don't dereference free:d descriptor

It appears that in the DMA40 driver the DMA tasklet will very
often dereference memory for a descriptor just free:d from the
DMA40 slab. Nothing happens because no other part of the driver
has yet had a chance to claim this memory, but it's really
nasty to dereference free:d memory, so let's check the flag
before the descriptor is free and store it in a bool variable.

Cc: stable@vger.kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
ARM64: unwind: Fix PC calculation

The frame PC value in the unwind code used to just take the saved LR
value and use that.  That's incorrect as a stack trace, since it shows
the return path stack, not the call path stack.

In particular, it shows faulty information in case the bl is done as
the very last instruction of one label, since the return point will be
in the next label. That can easily be seen with tail calls to panic(),
which is marked __noreturn and thus doesn't have anything useful after it.

Easiest here is to just correct the unwind code and do a -4, to get the
actual call site for the backtrace instead of the return site.

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
dm cache: move hook_info into common portion of per_bio_data structure

Commit c9d28d5d ("dm cache: promotion optimisation for writes")
incorrectly placed the 'hook_info' member in the writethrough-only
portion of the per_bio_data structure.

Given that the overwrite optimization may be used for writeback the
'hook_info' member must be placed above the 'cache' member of the
per_bio_data structure.  Any members above 'cache' are available from
both writeback and writethrough modes' per_bio_data structure.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
dm cache: do not add migration to completed list before unhooking bio

When completing an overwrite bio, in overwrite_endio(), the associated
migration should not be added to the 'completed_migrations' until the
bio's fields are restored with dm_unhook_bio().

Otherwise, do_worker() can race to process 'completed_migrations' before
dm_unhook_bio() -- so the bio's bi_end_io is incorrect.  This is
unlikely to cause any problems given the current code but should be
fixed on the basis of correctness.

Also, the cache's spinlock only needs to be held when manipulating the
'completed_migrations' list -- other changes don't need protection.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
dm thin: avoid metadata commit if a pool's thin devices haven't changed

Commit 905e51b ("dm thin: commit outstanding data every second")
introduced a periodic commit.  This commit occurs regardless of whether
any thin devices have made changes.

Fix the periodic commit to check if any of a pool's thin devices have
changed using dm_pool_changed_this_transaction().

Reported-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
dm io: fix I/O to multiple destinations

Commit 003b5c5719f159f4f4bf97511c4702a0638313dd ("block: Convert drivers
to immutable biovecs") broke dm-mirror due to dm-io breakage.

dm-io had three possible iterators (DM_IO_PAGE_LIST, DM_IO_BVEC,
DM_IO_VMA) that iterate over pages where the I/O should be performed.

The switch to immutable biovecs changed the DM_IO_BVEC iterator to
DM_IO_BIO.  Before this change the iterator stored the pointer to a bio
vector in the dpages structure.  The iterator incremented the pointer in
the dpages structure as it advanced over the pages.  After the immutable
biovecs change, the DM_IO_BIO iterator stores a pointer to the bio in
the dpages structure and uses bio_advance to change the bio as it
advances.

The problem is that the function dispatch_io stores the content of the
dpages structure into the variable old_pages and restores it before
issuing I/O to each of the devices.  Before the change, the statement
"*dp = old_pages;" restored the iterator to its starting position.
After the change, struct dpages holds a pointer to the bio, thus the
statement "*dp = old_pages;" doesn't restore the iterator.

Consequently, in the context of dm-mirror: only the first mirror leg is
written correctly, the kernel locks up when trying to write the other
mirror legs because the number of sectors to write in the where->count
variable doesn't match the number of sectors returned by the iterator.

This patch fixes the bug by partially reverting the original patch - it
changes the code so that struct dpages holds a pointer to the bio vector,
so that the statement "*dp = old_pages;" restores the iterator correctly.

The field "context_u" holds the offset from the beginning of the current
bio vector entry, just like the "bio->bi_iter.bi_bvec_done" field.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>