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506,942 commits

Author SHA1 Message Date
Vlad Yasevich
e558b0188b macvtap: Correctly set tap features when IFF_VNET_HDR is disabled.
When the user turns off IFF_VNET_HDR flag, attempts to change
offload features via TUNSETOFFLOAD do not work.  This could cause
GSO packets to be delivered to the user when the user is
not prepared to handle them.

To solve, allow processing of TUNSETOFFLOAD when IFF_VNET_HDR is
disabled.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-20 13:09:11 -07:00
Vlad Yasevich
a567dd6252 macvtap: simplify usage of tap_features
In macvtap, tap_features specific the features of that the user
has specified via ioctl().  If we treat macvtap as a macvlan+tap
then we could all the tap a pseudo-device and give it other features
like SG and GSO.  Then we can stop using the features of lower
device (macvlan) when forwarding the traffic the tap.

This solves the issue of possible checksum offload mismatch between
tap feature and macvlan features.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-20 13:09:11 -07:00
Andrey Vagin
7ed5c5ae96 tcp: set timestamps for restored skb-s
When the repair mode is turned off, the write queue seqs are
updated so that the whole queue is considered to be 'already sent.

The "when" field must be set for such skb. It's used in tcp_rearm_rto
for example. If the "when" field isn't set, the retransmit timeout can
be calculated incorrectly and a tcp connected can stop for two minutes
(TCP_RTO_MAX).

Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-20 13:07:15 -07:00
Zhi Yong Wu
ac0e300fa5 xfs: fix the comment of xlog_write_setup_copy()
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20 14:59:31 -05:00
Zhi Yong Wu
99e738b783 xfs: fix the comment of xfs_mod_incore_sb_unlocked()
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20 14:59:05 -05:00
Zhi Yong Wu
49d3da149c xfs: fix the comment of xfs_btree_lookup()
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20 14:45:23 -05:00
Zhi Yong Wu
b46fe8259b xfs: fix the comment of xfs_buf_free()
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20 14:44:39 -05:00
Zhi Yong Wu
0471f62e38 xfs: fix the comment of xfs_check_sizes()
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-20 14:42:16 -05:00
Vaughan Cao
669b0ae961 xen/pvhvm: Initialize xen panic handler for PVHVM guests
kernel use callback linked in panic_notifier_list to notice others when panic
happens.
NORET_TYPE void panic(const char * fmt, ...){
    ...
    atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
}
When Xen becomes aware of this, it will call xen_reboot(SHUTDOWN_crash) to
send out an event with reason code - SHUTDOWN_crash.

xen_panic_handler_init() is defined to register on panic_notifier_list but
we only call it in xen_arch_setup which only be called by PV, this patch is
necessary for PVHVM.

Without this patch, setting 'on_crash=coredump-restart' in PVHVM guest config
file won't lead a vmcore to be generate when the guest panics. It can be
reproduced with 'echo c > /proc/sysrq-trigger'.

Signed-off-by: Vaughan Cao <vaughan.cao@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Joe Jin <joe.jin@oracle.com>
2013-08-20 15:37:03 -04:00
Antti Palosaari
c59e6d5650 [media] msi3101: few improvements for RF tuner
* Fix AM_MODE. Now it could work at least in theory, cannot test.
* Use greatest common divisor algo to divide PLL fractional parts.
* Fix IF frequency mode.
* + some very minor "style" issues

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:09:04 -03:00
Antti Palosaari
0046079812 [media] msi3101: change stream format 384
After feeding different signal levels using RF generator and looking
GNU Radio FFT sink I made decision to change bit shift 3 to bit shift
2 as there was very (too) huge visible leap in FFT sink GUI. Now it
looks more natural.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:08:47 -03:00
Antti Palosaari
61198dfd08 [media] msi3101: implement stream format 504
That stream format carries 504 x I+Q samples per 1024 USB frame.
Sample resolution is 8-bit signed. Default it when sampling rate
is 9Msps or over.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:08:25 -03:00
Antti Palosaari
00e049b05a [media] msi3101: a lot of small cleanups
Add comments, remove useless code and so. House cleaning party.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:08:11 -03:00
Antti Palosaari
093cdc79a9 [media] msi3101: changes for tuner PLL freq limits
I made some tuner freq limit tests against RF signal generator.
Adjust some PLL limits according to these test results.
Here are the results, taken from two different devices.
Ranges are measured RF limits + calculated VCO limits.
Mirics MSi3101 SDR Dongle:
VHF_MODE  52 - 132  1664 - 4224
B3_MODE  103 - 263  1648 - 4208
B45_MODE 413 - 960  1652 - 3840
Hauppauge WinTV 133559 LF:
VHF_MODE  49 - 130  1568 - 4160
B3_MODE   98 - 259  1568 - 4144
B45_MODE 391 - 960  1564 - 3840

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:07:54 -03:00
Antti Palosaari
8e2efac7d2 [media] msi3101: add stream format 336 I+Q pairs per frame
That one seem to have 12-bit resolution. Use it for streams that
has sampling rate 6 <= rate (Msps) < 8, between 6 and 8Msps.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:07:29 -03:00
Antti Palosaari
35111f5bc9 [media] msi3101: fix overflow in freq setting
Higher frequencies were not possible to set correctly as that value
overflows.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:07:07 -03:00
Antti Palosaari
c5a431d02c [media] msi3101: init bits 23:20 on PLL register
It is not sure what is meaning of that number, but it is better
to try do as Windows driver. It seems to have small effect for
signal when looking FM FFT.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:06:56 -03:00
Antti Palosaari
554cbfbe3b [media] msi3101: add support for stream format "252" I+Q per frame
That one seems to have 14-bit ADC resolution, wow!
It is now used when sampling rate is below 6 Msps.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:06:33 -03:00
Antti Palosaari
23df427e33 [media] msi3101: improve tuner synth calc step size
Allow stepless synthesizer configuration. With that change we lose
precision a little bit, as it is now between +-500Hz from the target.
It could be better but on that case calculation algorithm goes more
complex and atm there is more important things to do.
Two approach to improve which comes to my mind are:
1) select and use biggest suitable step
2) use greatest common divisor algo to find divisor for thresh & frac
when possible to avoid rounding errors, which is root of cause of
current +-500Hz inaccuracy.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:04:50 -03:00
Antti Palosaari
22ca680e02 [media] msi3101: correct ADC sampling rate calc a little bit
No need to compare numbers, we could just store that fractional
value MSB directly.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:01:52 -03:00
Antti Palosaari
6450e5091c [media] msi3101: add debug dump for unknown stream data
Dump all unknown 'garbage' data - maybe we will discover someday if there
is something rational...
Also fix comment in USB frame description.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:01:28 -03:00
Antti Palosaari
42fc5b4230 [media] msi3101: add 2040:d300 Hauppauge WinTV 133559 LF
It is based Mirics MSi3101 reference design and will just work
without any changes.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 16:01:09 -03:00
Antti Palosaari
d0fadf4033 [media] msi3101: fix stream re-start halt
Restarting stream fails quite often. Small delay is between urb killing
and stream stop command - likely to give harware some time to process
killed urbs.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 15:59:18 -03:00
Paul E. McKenney
5a581b367b jiffies: Avoid undefined behavior from signed overflow
According to the C standard 3.4.3p3, overflow of a signed integer results
in undefined behavior.  This commit therefore changes the definitions
of time_after(), time_after_eq(), time_after64(), and time_after_eq64()
to avoid this undefined behavior.  The trick is that the subtraction
is done using unsigned arithmetic, which according to 6.2.5p9 cannot
overflow because it is defined as modulo arithmetic.  This has the added
(though admittedly quite small) benefit of shortening four lines of code
by four characters each.

Note that the C standard considers the cast from unsigned to
signed to be implementation-defined, see 6.3.1.3p3.  However, on a
two's-complement system, an implementation that defines anything other
than a reinterpretation of the bits is free to come to me, and I will be
happy to act as a witness for its being committed to an insane asylum.
(Although I have nothing against saturating arithmetic or signals in some
cases, these things really should not be the default when compiling an
operating-system kernel.)

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Kevin Easton <kevin@guarana.org>
[ paulmck: Included time_after64() and time_after_eq64(), as suggested
  by Eric Dumazet, also fixed commit message.]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-20 11:46:54 -07:00
Paul E. McKenney
458fb381ea rcu: Simplify _rcu_barrier() processing
This commit drops an unneeded ACCESS_ONCE() and simplifies an "our work
is done" check in _rcu_barrier().  This applies feedback from Linus
(https://lkml.org/lkml/2013/7/26/777) that he gave to similar code
in an unrelated patch.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
[ paulmck: Fix comment to match code, reported by Lai Jiangshan. ]
2013-08-20 11:45:50 -07:00
Paul E. McKenney
7a6a41073c rcu: Make rcutorture emit online failures if verbose
Although rcutorture counts CPU-hotplug online failures, it does
not explicitly record which CPUs were having trouble coming online.
This commit therefore emits a console message when online failure occurs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-20 11:38:45 -07:00
Paul E. McKenney
ef47db8e99 rcu: Remove unused variable from rcu_torture_writer()
The oldbatch variable in rcu_torture_writer() is stored to, but never
loaded from.  This commit therefore removes it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-20 11:38:43 -07:00
Paul E. McKenney
d10453e974 rcu: Sort rcutorture module parameters
There are getting to be too many module parameters to permit the current
semi-random order, so this patch orders them.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-20 11:38:42 -07:00
Paul E. McKenney
2ec1f2d987 rcu: Increase rcutorture test coverage
Currently, rcutorture has separate torture_types to test synchronous,
asynchronous, and expedited grace-period primitives.  This has
two disadvantages: (1) Three times the number of runs to cover the
combinations and (2) Little testing of concurrent combinations of the
three options.  This commit therefore adds a pair of module parameters
that control normal and expedited state, with the default being both
types, randomly selected, by the fakewriter processes, thus reducing
source-code size and increasing test coverage.  In addtion, the writer
task switches between asynchronous-normal and expedited grace-period
primitives driven by the same pair of module parameters.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-20 11:38:41 -07:00
Paul E. McKenney
d2818df168 rcu: Add duplicate-callback tests to rcutorture
This commit adds a object_debug option to rcutorture to allow the
debug-object-based checks for duplicate call_rcu() invocations to
be deterministically tested.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
[ paulmck: Banish mid-function ifdef, more or less per Josh Triplett. ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
[ paulmck: Improve duplicate-callback test, per Lai Jiangshan. ]
2013-08-20 11:37:54 -07:00
Christian Daudt
3a76b35186 ARM: bcm: Make secure API call optional
The current bcm_kona_smc_init function throws a BUG_ON if there's no SMC
device node defined in the device tree.

Since secure API access is optional depending the chip configuration,
fix this by allowing the rest of the code to run even if there's no SMC
device node defined

Signed-off-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
2013-08-20 10:51:39 -07:00
Christian Daudt
aea237bfa0 ARM: DT: binding fixup to align with vendor-prefixes.txt (drivers)
[ this is a follow-up to this discussion:
http://archive.arm.linux.org.uk/lurker/message/20130730.230827.a1ceb12a.en.html ]
This patchset renames all uses of "bcm," name bindings to
"brcm," as they were done prior to knowing that brcm had
already been standardized as Broadcom vendor prefix
(in Documentation/devicetree/bindings/vendor-prefixes.txt).
This will not cause any churn on devices because none of
these bindings have made it into production yet.

Signed-off-by: Christian Daudt <csd@broadcom.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
2013-08-20 10:51:38 -07:00
Christian Daudt
15e22ddf04 ARM: DT: binding fixup to align with vendor-prefixes.txt (DT)
[ this is a follow-up to this discussion:
http://archive.arm.linux.org.uk/lurker/message/20130730.230827.a1ceb12a.en.html ]
This patchset renames all uses of "bcm," name bindings to
"brcm," as they were done prior to knowing that brcm had
already been standardized as Broadcom vendor prefix
(in Documentation/devicetree/bindings/vendor-prefixes.txt).
This will not cause any churn on devices because none of
these bindings have made it into production yet.
Also rename the the following dt binding docs that had "bcm,"
in their name for consistency:
 - bcm,kona-sdhci.txt -> kona-sdhci.txt
 - bcm,kona-timer.txt -> kona-timer.txt

Signed-off-by: Christian Daudt <csd@broadcom.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
2013-08-20 10:47:47 -07:00
David Daney
c26d421987 MIPS: Handle OCTEON BBIT instructions in FPU emulator.
The branch emulation needs to handle the OCTEON BBIT instructions,
otherwise we get SIGILL instead of emulation.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5726/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-08-20 19:17:40 +02:00
Antti Palosaari
020046812f [media] msi3101: enhance sampling results
It looks like there is some extra data carried to enhance sampling
results. When you tune to some some weak/empty channel those bits
are always zeroes. When you tune to some channel where is very
strong signals those bits are all zeroes.
Examining those 32-bits reveals shortly there is 16 pieces of 2-bit
numbers. Number seen are 0, 1 and 3 - for some reason 2 is not used.
I used that number to shift bits given amount to left, "increasing"
sampling resolution by 3-bits. It may be wrong, but after some testing
it still provides better signal.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 13:58:55 -03:00
Antti Palosaari
3673b35cfa [media] msi3101: add sampling mode control
Whilst Quadrature Sampling is most common sampling technique used in
radio technology there is others too. Add control user could select
sampling mode. We currently support only quadrature sampling.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 13:40:54 -03:00
Antti Palosaari
b15208573d [media] msi3101: fix sampling rate calculation
These calculations seem to give 100% correct results. Calculation
formulas could be still a little bit wrong as I have no knowledge
what kind of dividers, multipliers and VCO limits there really is.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 13:33:46 -03:00
Antti Palosaari
34599b9b53 [media] msi3101: sample is correct term for sample
Just fix wrong term name. No functional changes.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 13:33:19 -03:00
Trond Myklebust
5948a401a7 NFS: Remove the NFSv4 "open optimisation" from nfs_permission
Ever since commit 6168f62cb (Add ACCESS operation to OPEN compound)
the NFSv4 atomic open has primed the access cache, and so nfs_permission
will no longer do an RPC call on the wire.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-20 12:29:27 -04:00
Antti Palosaari
977e444f59 [media] Mirics MSi3101 SDR Dongle driver
It is first Kernel software defined radio receiver driver.
That device is sold as a digital television solution.
MSi3101 is reference design which consists of two chips:
1) MSi2500 USB ADC
2) MSi001 RF-tuner
Driver is put to staging as API is not ready.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-08-20 13:23:58 -03:00
Christian Daudt
30ca653e59 ARM: dts: add sdio blocks to bcm28155-ap board
Enable sdio for bcm28155 AP board

Signed-off-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
2013-08-20 08:44:28 -07:00
Christian Daudt
d7358f8456 ARM: dts: align sdio numbers to HW definition
Clean up the sdio numbering to be 1-base as defined in HW spec,
instead of the current 0-base

Signed-off-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-08-20 08:44:23 -07:00
Richard Weinberger
8930fa500f UBI: Fix invalidate_fastmap()
Onging tests uncovered that invalidate_fastmap() is broken.
It must not call ubi_wl_put_fm_peb() because all PEBs used
by the old fastmap have already been put back.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2013-08-20 17:53:25 +03:00
Stefano Stabellini
ee0726407f xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping
GNTTABOP_unmap_grant_ref unmaps a grant and replaces it with a 0
mapping instead of reinstating the original mapping.
Doing so separately would be racy.

To unmap a grant and reinstate the original mapping atomically we use
GNTTABOP_unmap_and_replace.
GNTTABOP_unmap_and_replace doesn't work with GNTMAP_contains_pte, so
don't use it for kmaps.  GNTTABOP_unmap_and_replace zeroes the mapping
passed in new_addr so we have to reinstate it, however that is a
per-cpu mapping only used for balloon scratch pages, so we can be sure that
it's not going to be accessed while the mapping is not valid.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: alex@alex.org.uk
CC: dcrisan@flexiant.com

[v1: Konrad fixed up the conflicts]
Conflicts:
	arch/x86/xen/p2m.c
2013-08-20 10:25:35 -04:00
Stefano Stabellini
072b2064b8 xen: fix ARM build after 6efa20e4
The following commit:

commit 6efa20e49b
Author: Konrad Rzeszutek Wilk <konrad@kernel.org>
Date:   Fri Jul 19 11:51:31 2013 -0400

    xen: Support 64-bit PV guest receiving NMIs

breaks the Xen ARM build:

CC      drivers/xen/events.o
drivers/xen/events.c: In function 'xen_send_IPI_one':
drivers/xen/events.c:1218:6: error: 'XEN_NMI_VECTOR' undeclared (first use in this function)

Simply ifdef the undeclared symbol in the code.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-08-20 10:23:09 -04:00
Konrad Rzeszutek Wilk
c65a8370d7 MAINTAINERS: Remove Jeremy from the Xen subsystem.
Jeremy has been a key person in making Linux work with Xen.
He has been enjoying the last year working on something
different so reflect that in the maintainers file.

CC: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
2013-08-20 10:16:09 -04:00
David Vrabel
3ef0296a0b xen/events: document behaviour when scanning the start word for events
The original comment on the scanning of the start word on the 2nd pass
did not reflect the actual behaviour (the code was incorrectly masking
bit_idx instead of the pending word itself).

The documented behaviour is not actually required since if event were
pending in the MSBs, they would be immediately scanned anyway as we go
through the loop again.

Update the documentation to reflect this (instead of trying to change
the behaviour).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2013-08-20 10:15:28 -04:00
Chuck Anderson
fc78d343fa xen/smp: initialize IPI vectors before marking CPU online
An older PVHVM guest (v3.0 based) crashed during vCPU hot-plug with:

	kernel BUG at drivers/xen/events.c:1328!

RCU has detected that a CPU has not entered a quiescent state within the
grace period.  It needs to send the CPU a reschedule IPI if it is not
offline.  rcu_implicit_offline_qs() does this check:

	/*
	 * If the CPU is offline, it is in a quiescent state.  We can
	 * trust its state not to change because interrupts are disabled.
	 */
	if (cpu_is_offline(rdp->cpu)) {
		rdp->offline_fqs++;
		return 1;
	}

	Else the CPU is online.  Send it a reschedule IPI.

The CPU is in the middle of being hot-plugged and has been marked online
(!cpu_is_offline()).  See start_secondary():

	set_cpu_online(smp_processor_id(), true);
	...
	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;

start_secondary() then waits for the CPU bringing up the hot-plugged CPU to
mark it as active:

	/*
	 * Wait until the cpu which brought this one up marked it
	 * online before enabling interrupts. If we don't do that then
	 * we can end up waking up the softirq thread before this cpu
	 * reached the active state, which makes the scheduler unhappy
	 * and schedule the softirq thread on the wrong cpu. This is
	 * only observable with forced threaded interrupts, but in
	 * theory it could also happen w/o them. It's just way harder
	 * to achieve.
	 */
	while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
		cpu_relax();

	/* enable local interrupts */
	local_irq_enable();

The CPU being hot-plugged will be marked active after it has been fully
initialized by the CPU managing the hot-plug.  In the Xen PVHVM case
xen_smp_intr_init() is called to set up the hot-plugged vCPU's
XEN_RESCHEDULE_VECTOR.

The hot-plugging CPU is marked online, not marked active and does not have
its IPI vectors set up.  rcu_implicit_offline_qs() sees the hot-plugging
cpu is !cpu_is_offline() and tries to send it a reschedule IPI:
This will lead to:

	kernel BUG at drivers/xen/events.c:1328!

	xen_send_IPI_one()
	xen_smp_send_reschedule()
	rcu_implicit_offline_qs()
	rcu_implicit_dynticks_qs()
	force_qs_rnp()
	force_quiescent_state()
	__rcu_process_callbacks()
	rcu_process_callbacks()
	__do_softirq()
	call_softirq()
	do_softirq()
	irq_exit()
	xen_evtchn_do_upcall()

because xen_send_IPI_one() will attempt to use an uninitialized IRQ for
the XEN_RESCHEDULE_VECTOR.

There is at least one other place that has caused the same crash:

	xen_smp_send_reschedule()
	wake_up_idle_cpu()
	add_timer_on()
	clocksource_watchdog()
	call_timer_fn()
	run_timer_softirq()
	__do_softirq()
	call_softirq()
	do_softirq()
	irq_exit()
	xen_evtchn_do_upcall()
	xen_hvm_callback_vector()

clocksource_watchdog() uses cpu_online_mask to pick the next CPU to handle
a watchdog timer:

	/*
	 * Cycle through CPUs to check if the CPUs stay synchronized
	 * to each other.
	 */
	next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
	if (next_cpu >= nr_cpu_ids)
		next_cpu = cpumask_first(cpu_online_mask);
	watchdog_timer.expires += WATCHDOG_INTERVAL;
	add_timer_on(&watchdog_timer, next_cpu);

This resulted in an attempt to send an IPI to a hot-plugging CPU that
had not initialized its reschedule vector. One option would be to make
the RCU code check to not check for CPU offline but for CPU active.
As becoming active is done after a CPU is online (in older kernels).

But Srivatsa pointed out that "the cpu_active vs cpu_online ordering has been
completely reworked - in the online path, cpu_active is set *before* cpu_online,
and also, in the cpu offline path, the cpu_active bit is reset in the CPU_DYING
notification instead of CPU_DOWN_PREPARE." Drilling in this the bring-up
path: "[brought up CPU].. send out a CPU_STARTING notification, and in response
to that, the scheduler sets the CPU in the cpu_active_mask. Again, this mask
is better left to the scheduler alone, since it has the intelligence to use it
judiciously."

The conclusion was that:
"
1. At the IPI sender side:

   It is incorrect to send an IPI to an offline CPU (cpu not present in
   the cpu_online_mask). There are numerous places where we check this
   and warn/complain.

2. At the IPI receiver side:

   It is incorrect to let the world know of our presence (by setting
   ourselves in global bitmasks) until our initialization steps are complete
   to such an extent that we can handle the consequences (such as
   receiving interrupts without crashing the sender etc.)
" (from Srivatsa)

As the native code enables the interrupts at some point we need to be
able to service them. In other words a CPU must have valid IPI vectors
if it has been marked online.

It doesn't need to handle the IPI (interrupts may be disabled) but needs
to have valid IPI vectors because another CPU may find it in cpu_online_mask
and attempt to send it an IPI.

This patch will change the order of the Xen vCPU bring-up functions so that
Xen vectors have been set up before start_secondary() is called.
It also will not continue to bring up a Xen vCPU if xen_smp_intr_init() fails
to initialize it.

Orabug 13823853
Signed-off-by Chuck Anderson <chuck.anderson@oracle.com>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-08-20 10:13:05 -04:00
David Vrabel
4704fe4f03 xen/events: mask events when changing their VCPU binding
When a event is being bound to a VCPU there is a window between the
EVTCHNOP_bind_vpcu call and the adjustment of the local per-cpu masks
where an event may be lost.  The hypervisor upcalls the new VCPU but
the kernel thinks that event is still bound to the old VCPU and
ignores it.

There is even a problem when the event is being bound to the same VCPU
as there is a small window beween the clear_bit() and set_bit() calls
in bind_evtchn_to_cpu().  When scanning for pending events, the kernel
may read the bit when it is momentarily clear and ignore the event.

Avoid this by masking the event during the whole bind operation.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
CC: stable@vger.kernel.org
2013-08-20 10:13:04 -04:00
David Vrabel
84ca7a8e45 xen/events: initialize local per-cpu mask for all possible events
The sizeof() argument in init_evtchn_cpu_bindings() is incorrect
resulting in only the first 64 (or 32 in 32-bit guests) ports having
their bindings being initialized to VCPU 0.

In most cases this does not cause a problem as request_irq() will set
the irq affinity which will set the correct local per-cpu mask.
However, if the request_irq() is called on a VCPU other than 0, there
is a window between the unmasking of the event and the affinity being
set were an event may be lost because it is not locally unmasked on
any VCPU. If request_irq() is called on VCPU 0 then local irqs are
disabled during the window and the race does not occur.

Fix this by initializing all NR_EVENT_CHANNEL bits in the local
per-cpu masks.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
2013-08-20 10:13:02 -04:00