Commit Graph

562419 Commits

Author SHA1 Message Date
Michael S. Tsirkin
43e361f23c checkpatch: add virt barriers
Add virt_ barriers to list of barriers to check for
presence of a comment.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Julian Calaby <julian.calaby@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:08 +02:00
Michael S. Tsirkin
f4073b0f6e checkpatch: check for __smp outside barrier.h
Introduction of __smp barriers cleans up a bunch of duplicate code, but
it gives people an additional handle onto a "new" set of barriers - just
because they're prefixed with __* unfortunately doesn't stop anyone from
using it (as happened with other arch stuff before.)

Add a checkpatch test so it will trigger a warning.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Julian Calaby <julian.calaby@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:07 +02:00
Michael S. Tsirkin
402c2553a2 checkpatch.pl: add missing memory barriers
SMP-only barriers were missing in checkpatch.pl

Refactor code slightly to make adding more variants easier.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Julian Calaby <julian.calaby@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:07 +02:00
Stefan Hajnoczi
f7ad26ff95 virtio: make find_vqs() checkpatch.pl-friendly
checkpatch.pl wants arrays of strings declared as follows:

  static const char * const names[] = { "vq-1", "vq-2", "vq-3" };

Currently the find_vqs() function takes a const char *names[] argument
so passing checkpatch.pl's const char * const names[] results in a
compiler error due to losing the second const.

This patch adjusts the find_vqs() prototype and updates all virtio
transports.  This makes it possible for virtio_balloon.c, virtio_input.c,
virtgpu_kms.c, and virtio_rpmsg_bus.c to use the checkpatch.pl-friendly
type.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
2016-01-12 20:47:06 +02:00
Minchan Kim
21ea9fb69e virtio_balloon: fix race between migration and ballooning
In balloon_page_dequeue, pages_lock should cover the loop
(ie, list_for_each_entry_safe). Otherwise, the cursor page could
be isolated by compaction and then list_del by isolation could
poison the page->lru.{prev,next} so the loop finally could
access wrong address like this. This patch fixes the bug.

general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 2 PID: 82 Comm: vballoon Not tainted 4.4.0-rc5-mm1-access_bit+ #1906
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff8800a7ff0000 ti: ffff8800a7fec000 task.ti: ffff8800a7fec000
RIP: 0010:[<ffffffff8115e754>]  [<ffffffff8115e754>] balloon_page_dequeue+0x54/0x130
RSP: 0018:ffff8800a7fefdc0  EFLAGS: 00010246
RAX: ffff88013fff9a70 RBX: ffffea000056fe00 RCX: 0000000000002b7d
RDX: ffff88013fff9a70 RSI: ffffea000056fe00 RDI: ffff88013fff9a68
RBP: ffff8800a7fefde8 R08: ffffea000056fda0 R09: 0000000000000000
R10: ffff8800a7fefd90 R11: 0000000000000001 R12: dead0000000000e0
R13: ffffea000056fe20 R14: ffff880138809070 R15: ffff880138809060
FS:  0000000000000000(0000) GS:ffff88013fc40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f229c10e000 CR3: 00000000b8b53000 CR4: 00000000000006a0
Stack:
 0000000000000100 ffff880138809088 ffff880138809000 ffff880138809060
 0000000000000046 ffff8800a7fefe28 ffffffff812c86d3 ffff880138809020
 ffff880138809000 fffffffffff91900 0000000000000100 ffff880138809060
Call Trace:
 [<ffffffff812c86d3>] leak_balloon+0x93/0x1a0
 [<ffffffff812c8bc7>] balloon+0x217/0x2a0
 [<ffffffff8143739e>] ? __schedule+0x31e/0x8b0
 [<ffffffff81078160>] ? abort_exclusive_wait+0xb0/0xb0
 [<ffffffff812c89b0>] ? update_balloon_stats+0xf0/0xf0
 [<ffffffff8105b6e9>] kthread+0xc9/0xe0
 [<ffffffff8105b620>] ? kthread_park+0x60/0x60
 [<ffffffff8143b4af>] ret_from_fork+0x3f/0x70
 [<ffffffff8105b620>] ? kthread_park+0x60/0x60
Code: 8d 60 e0 0f 84 af 00 00 00 48 8b 43 20 a8 01 75 3b 48 89 d8 f0 0f ba 28 00 72 10 48 8b 03 f6 c4 08 75 2f 48 89 df e8 8c 83 f9 ff <49> 8b 44 24 20 4d 8d 6c 24 20 48 83 e8 20 4d 39 f5 74 7a 4c 89
RIP  [<ffffffff8115e754>] balloon_page_dequeue+0x54/0x130
 RSP <ffff8800a7fefdc0>
---[ end trace 43cf28060d708d5f ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled

Cc: <stable@vger.kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
2016-01-12 20:47:06 +02:00
Minchan Kim
f68b992bbb virtio_balloon: fix race by fill and leak
During my compaction-related stuff, I encountered a bug
with ballooning.

With repeated inflating and deflating cycle, guest memory(
ie, cat /proc/meminfo | grep MemTotal) is decreased and
couldn't be recovered.

The reason is balloon_lock doesn't cover release_pages_balloon
so struct virtio_balloon fields could be overwritten by race
of fill_balloon(e,g, vb->*pfns could be critical).

This patch fixes it in my test.

Cc: <stable@vger.kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-01-12 20:47:05 +02:00
Michael S. Tsirkin
779a6a3696 s390: more efficient smp barriers
As per: lkml.kernel.org/r/20150921112252.3c2937e1@mschwide
atomics imply a barrier on s390, so s390 should change
smp_mb__before_atomic and smp_mb__after_atomic to barrier() instead of
smp_mb() and hence should not use the generic versions.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:05 +02:00
Michael S. Tsirkin
a677f48695 s390: use generic memory barriers
The s390 kernel is SMP to 99.99%, we just didn't bother with a
non-smp variant for the memory-barriers. If the generic header
is used we'd get the non-smp version for free. It will save a
small amount of text space for CONFIG_SMP=n.

Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:04 +02:00
Michael S. Tsirkin
234927540e xen/events: use virt_xxx barriers
drivers/xen/events/events_fifo.c uses rmb() to communicate with the
other side.

For guests compiled with CONFIG_SMP, smp_rmb would be sufficient, so
rmb() here is only needed if a non-SMP guest runs on an SMP host.

Switch to the virt_rmb barrier which serves this exact purpose.

Pull in asm/barrier.h here to make sure the file is self-contained.

Suggested-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:04 +02:00
Michael S. Tsirkin
506b02eb1c xen/io: use virt_xxx barriers
include/xen/interface/io/ring.h uses
full memory barriers to communicate with the other side.

For guests compiled with CONFIG_SMP, smp_wmb and smp_mb
would be sufficient, so mb() and wmb() here are only needed if
a non-SMP guest runs on an SMP host.

Switch to virt_xxx barriers which serve this exact purpose.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:03 +02:00
Michael S. Tsirkin
5bb0c9be2a xenbus: use virt_xxx barriers
drivers/xen/xenbus/xenbus_comms.c uses
full memory barriers to communicate with the other side.

For guests compiled with CONFIG_SMP, smp_wmb and smp_mb
would be sufficient, so mb() and wmb() here are only needed if
a non-SMP guest runs on an SMP host.

Switch to virt_xxx barriers which serve this exact purpose.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:03 +02:00
Michael S. Tsirkin
788e5b3a5d virtio_ring: use virt_store_mb
We need a full barrier after writing out event index, using
virt_store_mb there seems better than open-coding.  As usual, we need a
wrapper to account for strong barriers.

It's tempting to use this in vhost as well, for that, we'll
need a variant of smp_store_mb that works on __user pointers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:02 +02:00
Michael S. Tsirkin
9e3f84ce41 sh: move xchg_cmpxchg to a header by itself
Looks like future sh variants will support a 4-byte cas which will be
used to implement 1 and 2 byte xchg.

This is exactly what we do for llsc now, move the portable part of the
code into a separate header so it's easy to reuse.

Suggested-by:  Rich Felker <dalias@libc.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:02 +02:00
Michael S. Tsirkin
3226aad81a sh: support 1 and 2 byte xchg
This completes the xchg implementation for sh architecture.  Note: The
llsc variant is tricky since this only supports 4 byte atomics, the
existing implementation of 1 byte xchg is wrong: we need to do a 4 byte
cmpxchg and retry if any bytes changed meanwhile.

Write this in C for clarity.

Suggested-by: Rich Felker <dalias@libc.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:01 +02:00
Michael S. Tsirkin
a65961272e virtio_ring: update weak barriers to use virt_xxx
virtio ring uses smp_wmb on SMP and wmb on !SMP,
the reason for the later being that it might be
talking to another kernel on the same SMP machine.

This is exactly what virt_xxx barriers do,
so switch to these instead of homegrown ifdef hacks.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:00 +02:00
Michael S. Tsirkin
d307fb16f7 Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb"
This reverts commit 9e1a27ea42.

While that commit optimizes !CONFIG_SMP, it mixes
up DMA and SMP concepts, making the code hard
to figure out.

A better way to optimize this is with the new __smp_XXX
barriers.

As a first step, go back to full rmb/wmb barriers
for !SMP.
We switch to __smp_XXX barriers in the next patch.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:47:00 +02:00
Michael S. Tsirkin
6a65d26385 asm-generic: implement virt_xxx memory barriers
Guests running within virtual machines might be affected by SMP effects even if
the guest itself is compiled without SMP support.  This is an artifact of
interfacing with an SMP host while running an UP kernel.  Using mandatory
barriers for this use-case would be possible but is often suboptimal.

In particular, virtio uses a bunch of confusing ifdefs to work around
this, while xen just uses the mandatory barriers.

To better handle this case, low-level virt_mb() etc macros are made available.
These are implemented trivially using the low-level __smp_xxx macros,
the purpose of these wrappers is to annotate those specific cases.

These have the same effect as smp_mb() etc when SMP is enabled, but generate
identical code for SMP and non-SMP systems. For example, virtual machine guests
should use virt_mb() rather than smp_mb() when synchronizing against a
(possibly SMP) host.

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:59 +02:00
Michael S. Tsirkin
1638fb7207 x86: define __smp_xxx
This defines __smp_xxx barriers for x86,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-12 20:46:59 +02:00
Michael S. Tsirkin
1ce790913b xtensa: define __smp_xxx
This defines __smp_xxx barriers for xtensa,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:58 +02:00
Michael S. Tsirkin
d39886a7d3 tile: define __smp_xxx
This defines __smp_xxx barriers for tile,
for use by virtualization.

Some smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: for 32 bit, keep smp_mb__after_atomic around since it's faster
than the generic implementation.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:58 +02:00
Michael S. Tsirkin
45d9b85941 sparc: define __smp_xxx
This defines __smp_xxx barriers for sparc,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:57 +02:00
Michael S. Tsirkin
90a3ccb0be sh: define __smp_xxx, fix smp_store_mb for !SMP
sh variant of smp_store_mb() calls xchg() on !SMP which is stronger than
implied by both the name and the documentation.

define __smp_store_mb instead: code in asm-generic/barrier.h
will then define smp_store_mb correctly depending on
CONFIG_SMP.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:57 +02:00
Michael S. Tsirkin
82b44496ab s390: define __smp_xxx
This defines __smp_xxx barriers for s390,
for use by virtualization.

Some smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: smp_mb, smp_rmb and smp_wmb are defined as full barriers
unconditionally on this architecture.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:56 +02:00
Michael S. Tsirkin
a60514bae7 mips: define __smp_xxx
This defines __smp_xxx barriers for mips,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: the only exception is smp_mb__before_llsc which is mips-specific.
We define both the __smp_mb__before_llsc variant (for use in
asm/barriers.h) and smp_mb__before_llsc (for use elsewhere on this
architecture).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:56 +02:00
Michael S. Tsirkin
afc22de0c0 metag: define __smp_xxx
This defines __smp_xxx barriers for metag,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: as __smp_XX macros should not depend on CONFIG_SMP, they can not
use the existing fence() macro since that is defined differently between
SMP and !SMP.  For this reason, this patch introduces a wrapper
metag_fence() that doesn't depend on CONFIG_SMP.
fence() is then defined using that, depending on CONFIG_SMP.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:55 +02:00
Michael S. Tsirkin
eebd1b9278 ia64: define __smp_xxx
This defines __smp_xxx barriers for ia64,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

This reduces the amount of arch-specific boiler-plate code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:55 +02:00
Michael S. Tsirkin
27f6cabc0e blackfin: define __smp_xxx
This defines __smp_xxx barriers for blackfin,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:54 +02:00
Michael S. Tsirkin
2b1f3de102 arm: define __smp_xxx
This defines __smp_xxx barriers for arm,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

This reduces the amount of arch-specific boiler-plate code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:54 +02:00
Michael S. Tsirkin
fd072df850 arm64: define __smp_xxx
This defines __smp_xxx barriers for arm64,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: arm64 does not support !SMP config,
so smp_xxx and __smp_xxx are always equivalent.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:53 +02:00
Michael S. Tsirkin
003472a93a powerpc: define __smp_xxx
This defines __smp_xxx barriers for powerpc
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

This reduces the amount of arch-specific boiler-plate code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:53 +02:00
Michael S. Tsirkin
a9e4252a9b asm-generic: add __smp_xxx wrappers
On !SMP, most architectures define their
barriers as compiler barriers.
On SMP, most need an actual barrier.

Make it possible to remove the code duplication for
!SMP by defining low-level __smp_xxx barriers
which do not depend on the value of SMP, then
use them from asm-generic conditionally.

Besides reducing code duplication, these low level APIs will also be
useful for virtualization, where a barrier is sometimes needed even if
!SMP since we might be talking to another kernel on the same SMP system.

Both virtio and Xen drivers will benefit.

The smp_xxx variants should use __smp_XXX ones or barrier() depending on
SMP, identically for all architectures.

We keep ifndef guards around them for now - once/if all
architectures are converted to use the generic
code, we'll be able to remove these.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:52 +02:00
Michael S. Tsirkin
300b06d455 x86: reuse asm-generic/barrier.h
As on most architectures, on x86 read_barrier_depends and
smp_read_barrier_depends are empty.  Drop the local definitions and pull
the generic ones from asm-generic/barrier.h instead: they are identical.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-12 20:46:52 +02:00
Michael S. Tsirkin
577f183acc x86/um: reuse asm-generic/barrier.h
On x86/um CONFIG_SMP is never defined.  As a result, several macros
match the asm-generic variant exactly. Drop the local definitions and
pull in asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Richard Weinberger <richard@nod.at>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:51 +02:00
Michael S. Tsirkin
fa083e28f8 mips: reuse asm-generic/barrier.h
On mips dma_rmb, dma_wmb, smp_store_mb, read_barrier_depends,
smp_read_barrier_depends, smp_store_release and smp_load_acquire  match
the asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:51 +02:00
Michael S. Tsirkin
abe114d9f0 metag: reuse asm-generic/barrier.h
On metag dma_rmb, dma_wmb, smp_store_mb, read_barrier_depends,
smp_read_barrier_depends, smp_store_release and smp_load_acquire  match
the asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:50 +02:00
Michael S. Tsirkin
90ff6a17d0 arm64: reuse asm-generic/barrier.h
On arm64 nop, read_barrier_depends, smp_read_barrier_depends
smp_store_mb(), smp_mb__before_atomic and smp_mb__after_atomic match the
asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:50 +02:00
Michael S. Tsirkin
335390d609 arm: reuse asm-generic/barrier.h
On arm smp_store_mb, read_barrier_depends, smp_read_barrier_depends,
smp_store_release, smp_load_acquire, smp_mb__before_atomic and
smp_mb__after_atomic match the asm-generic variants exactly. Drop the
local definitions and pull in asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:49 +02:00
Michael S. Tsirkin
519be0438e sparc: reuse asm-generic/barrier.h
On sparc 64 bit dma_rmb, dma_wmb, smp_store_mb, smp_mb, smp_rmb,
smp_wmb, read_barrier_depends and smp_read_barrier_depends match the
asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

nop uses __asm__ __volatile but is otherwise identical to
the generic version, drop that as well.

This is in preparation to refactoring this code area.

Note: nop() was in processor.h and not in barrier.h as on other
architectures. Nothing seems to depend on it being there though.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:49 +02:00
Michael S. Tsirkin
21535aaed9 s390: reuse asm-generic/barrier.h
On s390 read_barrier_depends, smp_read_barrier_depends
smp_store_mb(), smp_mb__before_atomic and smp_mb__after_atomic match the
asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:48 +02:00
Michael S. Tsirkin
fbd7ec0236 powerpc: reuse asm-generic/barrier.h
On powerpc read_barrier_depends, smp_read_barrier_depends
smp_store_mb(), smp_mb__before_atomic and smp_mb__after_atomic match the
asm-generic variants exactly. Drop the local definitions and pull in
asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-01-12 20:46:48 +02:00
Michael S. Tsirkin
53a05ac15e ia64: reuse asm-generic/barrier.h
On ia64 smp_rmb, smp_wmb, read_barrier_depends, smp_read_barrier_depends
and smp_store_mb() match the asm-generic variants exactly. Drop the
local definitions and pull in asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:47 +02:00
Michael S. Tsirkin
9505ec0825 ia64: rename nop->iosapic_nop
asm-generic/barrier.h defines a nop() macro.
To be able to use this header on ia64, we shouldn't
call local functions/variables nop().

There's one instance where this breaks on ia64:
rename the function to iosapic_nop to avoid the conflict.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:47 +02:00
Michael S. Tsirkin
57f7c0370f asm-generic: guard smp_store_release/load_acquire
Allow architectures to override smp_store_release
and smp_load_acquire by guarding the defines
in asm-generic/barrier.h with ifndef directives.

This is in preparation to reusing asm-generic/barrier.h
on architectures which have their own definition
of these macros.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-01-12 20:46:46 +02:00
Davidlohr Bueso
5a1b26d7c6 lcoking/barriers, arch: Use smp barriers in smp_store_release()
With commit b92b8b35a2 ("locking/arch: Rename set_mb() to smp_store_mb()")
it was made clear that the context of this call (and thus set_mb)
is strictly for CPU ordering, as opposed to IO. As such all archs
should use the smp variant of mb(), respecting the semantics and
saving a mandatory barrier on UP.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1445975631-17047-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-01-12 20:46:46 +02:00
Linus Torvalds
afd2ff9b7e Linux 4.4 2016-01-10 15:01:32 -08:00
Linus Torvalds
eac6f76ac7 SCSI fixes on 20160109
Single fix for machines with pages > 4k (PPC mostly).  There's a bug in our
 optimal transfer size code where we don't account for pages > 4k and can set
 the transfer size to be less than the page size causing nasty failures.
 
 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fix from James Bottomley:
 "A single fix for machines with pages > 4k (PPC mostly).

  There's a bug in our optimal transfer size code where we don't account
  for pages > 4k and can set the transfer size to be less than the page
  size causing nasty failures"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Reject optimal transfer length smaller than page size
2016-01-09 14:53:48 -08:00
Linus Torvalds
c0cb139345 PCI updates for v4.4:
TI DRA7xx host bridge driver
     Mark driver as broken (Richard Cochran)
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Merge tag 'pci-v4.4-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixlet from Bjorn Helgaas:
 "This marks the TI DRA7xx host bridge driver as broken.  Apparently it
  has never worked without some additional out-of-tree code, so I'm
  going to mark it broken now and remove it completely next cycle unless
  it's fixed"

* tag 'pci-v4.4-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: dra7xx: Mark driver as broken
2016-01-09 14:44:44 -08:00
Michal Hocko
751e5f5c75 vmstat: allocate vmstat_wq before it is used
kernel test robot has reported the following crash:

  BUG: unable to handle kernel NULL pointer dereference at 00000100
  IP: [<c1074df6>] __queue_work+0x26/0x390
  *pdpt = 0000000000000000 *pde = f000ff53f000ff53 *pde = f000ff53f000ff53
  Oops: 0000 [#1] PREEMPT PREEMPT SMP SMP
  CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.4.0-rc4-00139-g373ccbe #1
  Workqueue: events vmstat_shepherd
  task: cb684600 ti: cb7ba000 task.ti: cb7ba000
  EIP: 0060:[<c1074df6>] EFLAGS: 00010046 CPU: 0
  EIP is at __queue_work+0x26/0x390
  EAX: 00000046 EBX: cbb37800 ECX: cbb37800 EDX: 00000000
  ESI: 00000000 EDI: 00000000 EBP: cb7bbe68 ESP: cb7bbe38
   DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
  CR0: 8005003b CR2: 00000100 CR3: 01fd5000 CR4: 000006b0
  Stack:
  Call Trace:
    __queue_delayed_work+0xa1/0x160
    queue_delayed_work_on+0x36/0x60
    vmstat_shepherd+0xad/0xf0
    process_one_work+0x1aa/0x4c0
    worker_thread+0x41/0x440
    kthread+0xb0/0xd0
    ret_from_kernel_thread+0x21/0x40

The reason is that start_shepherd_timer schedules the shepherd work item
which uses vmstat_wq (vmstat_shepherd) before setup_vmstat allocates
that workqueue so if the further initialization takes more than HZ we
might end up scheduling on a NULL vmstat_wq.  This is really unlikely
but not impossible.

Fixes: 373ccbe592 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress")
Reported-by: kernel test robot <ying.huang@linux.intel.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-08 23:47:54 -08:00
Linus Torvalds
44d8a7d5c1 ARM: SoC fixes for 4.4-rc
This is the final small set of ARM SoC bug fixes for linux-4.4,
 almost all regressions:
 
 OMAP:		data corruption on the Nokia N900 flash
 Allwinner:	Two defconfig change to get USB working again
 ARM Versatile:	Interrupt numbers gone bad after an older bug fix
 Nomadik:	Crashes from incorrect L2 cache settings
 VIA vt8500:	SD/MMC support on WM8650 never worked
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Arnd Bergmann:
 "This is the final small set of ARM SoC bug fixes for linux-4.4, almost
  all regressions:

  OMAP:
   - data corruption on the Nokia N900 flash

  Allwinner:
   - Two defconfig change to get USB working again

  ARM Versatile:
   - Interrupt numbers gone bad after an older bug fix

  Nomadik:
   - Crashes from incorrect L2 cache settings

  VIA vt8500:
   - SD/MMC support on WM8650 never worked"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  dts: vt8500: Add SDHC node to DTS file for WM8650
  ARM: Fix broken USB support in multi_v7_defconfig for sunxi devices
  ARM: versatile: fix MMC/SD interrupt assignment
  ARM: nomadik: set latencies to 8 cycles
  ARM: OMAP2+: Fix onenand rate detection to avoid filesystem corruption
  ARM: Fix broken USB support in sunxi_defconfig
2016-01-08 16:11:05 -08:00
Linus Torvalds
516c50cde6 A simple fix. I'm sending it before the merge window, because it refines
a patch found in your master branch but not yet in the kvm/next branch
 that is destined for 4.5.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fix from Paolo Bonzini:
 "A simple fix.  I'm sending it before the merge window, because it
  refines a patch found in your master branch but not yet in the
  kvm/next branch that is destined for 4.5"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: only channel 0 of the i8254 is linked to the HPET
2016-01-08 15:58:14 -08:00