Some devices may have different features despite sharing the same ID
(e.g. PCI ID). For example 14e4:4331 is usually a dual band, but this
can be "limited". Device with "pci/x/y/devid=0x4332" supports 2.4 GHz
only. Similarly 0x4333 will mean support for 5 GHz only.
Add entry in SPROM so info described above can be extracted and stored.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The debug controller, as its name suggests, exposes cgroup core
internals to userland to aid debugging. Unfortunately, except for the
name, there's no provision to prevent its usage in production
configurations and the controller is widely enabled and mounted
leaking internal details to userland. Like most other debug
information, the information exposed by debug isn't interesting even
for debugging itself once the related parts are working reliably.
This controller has no reason for existing. This patch implements
cgrp_dfl_root_inhibit_ss_mask which can suppress specific subsystems
on the default hierarchy and adds the debug subsystem to it so that it
can be gradually deprecated as usages move towards the unified
hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Some sysrq handlers can run for a long time, because they dump a lot
of data onto a serial console. Having RCU stall warnings pop up in
the middle of them only makes the problem worse.
This commit provides rcu_sysrq_start() and rcu_sysrq_end() APIs to
temporarily suppress RCU CPU stall warnings while a sysrq request is
handled.
Signed-off-by: Rik van Riel <riel@redhat.com>
[ paulmck: Fix TINY_RCU build error. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Each hardware queue has a bitmap of software queues with pending
requests. When new IO is queued on a software queue, the bit is
set, and when IO is pruned on a hardware queue run, the bit is
cleared. This causes a lot of traffic. Switch this from the regular
BITS_PER_LONG bitmap to a sparser layout, similarly to what was
done for blk-mq tagging.
20% performance increase was observed for single threaded IO, and
about 15% performanc increase on multiple threads driving the
same device.
Signed-off-by: Jens Axboe <axboe@fb.com>
Alexander noticed that we use RCU iteration on rb->event_list but do
not use list_{add,del}_rcu() to add,remove entries to that list, nor
do we observe proper grace periods when re-using the entries.
Merge ring_buffer_detach() into ring_buffer_attach() such that
attaching to the NULL buffer is detaching.
Furthermore, ensure that between any 'detach' and 'attach' of the same
event we observe the required grace period, but only when strictly
required. In effect this means that only ioctl(.request =
PERF_EVENT_IOC_SET_OUTPUT) will wait for a grace period, while the
normal initial attach and final detach will not be delayed.
This patch should, I think, do the right thing under all
circumstances, the 'normal' cases all should never see the extra grace
period, but the two cases:
1) PERF_EVENT_IOC_SET_OUTPUT on an event which already has a
ring_buffer set, will now observe the required grace period between
removing itself from the old and attaching itself to the new buffer.
This case is 'simple' in that both buffers are present in
perf_event_set_output() one could think an unconditional
synchronize_rcu() would be sufficient; however...
2) an event that has a buffer attached, the buffer is destroyed
(munmap) and then the event is attached to a new/different buffer
using PERF_EVENT_IOC_SET_OUTPUT.
This case is more complex because the buffer destruction does:
ring_buffer_attach(.rb = NULL)
followed by the ioctl() doing:
ring_buffer_attach(.rb = foo);
and we still need to observe the grace period between these two
calls due to us reusing the event->rb_entry list_head.
In order to make 2 happen we use Paul's latest cond_synchronize_rcu()
call.
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507123526.GD13658@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Armin pointed me to the fact that the identifier which is used to ensure the
unique include processing in lunux/include/uapi/linux/can.h is CAN_H.
This clashed with his own source as includes from libraries and APIs should
use an underscore '_' at the identifier start.
This patch fixes the protection identifiers in all CAN relavant includes.
Reported-by: Armin Burchardt <armin@uni-bremen.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The configuration is stored in NVRAM on the maXTouch chip. When the device
is reset it reports a CRC of the stored configuration values. Therefore it
isn't necessary to send the configuration on each probe - we can check the
CRC matches and avoid a timeconsuming backup/reset cycle.
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
* The mapping of the GPIO numbers into the T19 status byte varies between
different maXTouch chips. Some have up to 7 GPIOs. Allowing a keycode array
of up to 8 items is simpler and more generic. So replace #define with
configurable number of keys which also allows the removal of is_tp.
* Rename platform data parameters to include "t19" to prevent confusion with
T15 key array.
* Probe aborts early on when pdata is NULL, so no need to check.
* Move "int i" to beginning of function (mixed declarations and code)
* Use API calls rather than __set_bit()
* Remove unused dev variable.
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Yufeng Shen <miletus@chromium.org>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
It is not necessary to download these values to the maXTouch chip on every
probe, since they are stored in NVRAM. It makes life difficult when tuning
the device to keep them in sync with the config array/file, and requires a
new kernel build for minor tweaks.
These parameters only represent a tiny subset of the available
configuration options, tracking all of these options in platform data would
be a endless task. In addition, different versions of maXTouch chips may
have these values in different places or may not even have them at all.
Having these values also makes life more complex for device tree and other
platforms where having to define a static configuration isn't helpful.
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Get rid of the attb_read_val() platform hook. Instead, read the ATTB gpio
directly from the driver.
Fail if valid ATTB gpio is not provided by patform data.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Introduce helper functions to configure power and interrupt registers.
Default to IDLE mode on probe as device supports auto wakeup to ACVIE mode
on detecting finger touch.
Configure interrupt mode and polarity on start up. Power down on device
closure or module removal.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Fix following warnings:
smp_32.c:177:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
smp_64.c:1202:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
smp_64.c:989:6: warning: symbol 'kgdb_roundup_cpus' was not declared. Should it be static?
Add prototype to include/linux/profile.h of setup_profiling_timer
Add missing include to smp_64.c
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This would be a no-op, so there is no reason to request it.
This also allows conversion of the current implementations of
ethtool_ops::{get,set}_rxfh_indir to ethtool_ops::{get,set}_rxfh
with no change other than their parameters.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
There are several fixes in this patch (mostly because it's hard
splitting them up):
- Revert the name field in struct hwrng back to 'const'. Also, don't
do an extra kmalloc for the name - just wasteful.
- Deal with allocation failures properly.
- Use IDA to allocate device number instead of brute forcing one.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Calling netif_carrier_{on,off} is sufficient. There is no need
to duplicate the carrier state in a driver specific flag.
Acked-by: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lots of devices request much larger buffers than reasonable. This
cause real problems for users of hosts with limited resources.
Reducing the default buffer size to 16kB for such devices is
a reasonable trade-off between allowing them to aggregate traffic
and avoiding memory exhaustion on resource restrained hosts.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
To have an idea of the effects of the protocol coalescing
it's useful to have some counters showing the different
aspects.
Due to the asymmetrical usbnet interface the netdev
rx_bytes counter has been counting real received payload,
while the tx_bytes counter has included the NCM/MBIM
framing overhead. This overhead can be many times the
payload because of the aggressive padding strategy of
this driver, and will vary a lot depending on device
and traffic.
With very few exceptions, users are only interested in
the payload size. Having an somewhat accurate payload
byte counter is particularly important for mobile
broadband devices, which many NCM devices and of course
all MBIM devices are. Users and userspace applications
will use this counter to monitor account quotas.
Having protocol specific counters for the overhead, we are
now able to correct the tx_bytes netdev counter so that
it shows the real payload
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
We pad frames larger than X to maximum size for devices which
don't need a ZLP after maximum sized frames. This allows the
device to optimize its transfers for one fixed buffer size.
X was arbitrarily set at 512 bytes regardless of real buffer
maximum, causing extreme overheads due to excessive padding of
larger tx buffers. Limit the padding to at most 3 full USB
packets, still allowing the overhead to payload ratio of 3/1.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many newer NCM and MBIM devices will request a maximum tx
datagram count which is much smaller than our hard-coded
absolute max. We can reduce the overhead without sacrificing
any of the simplicity for these devices, by simply using the
true negotiated count in when calculated the maximum NTH and
NDP header sizes.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Datagram coalescing is an integral part of the NCM and MBIM
protocols, intended to reduce the interrupt load primarily
on the device end of the USB link. As with all coalescing
solutions, there is a trade-off between buffering and
interrupts.
The current defaults are based on the assumption that device
side buffers should be the limiting factor. However, many
modern high speed LTE modems suffers from buffer-bloat,
making this assumption fail. This results in sub-optimal
performance due to excessive coalescing. And in cases where
such modems are connected to cheap embedded hosts there is
often severe buffer allocation issues, giving very noticeable
performance degradation .
A start on improving this is going from build time hard
coded limits to per device user configurable limits. The
ethtool coalescing API was selected as user interface
because, although the tuned values are buffer sizes, these
settings directly control datagram coalescing.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prior to commit fbd929f2dc
bonding: support QinQ for bond arp interval
the arp monitoring code allowed for proper detection of devices
stacked on top of vlans. Since the above commit, the
code can still detect a device stacked on top of single
vlan, but not a device stacked on top of Q-in-Q configuration.
The search will only set the inner vlan tag if the route
device is the vlan device. However, this is not always the
case, as it is possible to extend the stacked configuration.
With this patch it is possible to provision devices on
top Q-in-Q vlan configuration that should be used as
a source of ARP monitoring information.
For example:
ip link add link bond0 vlan10 type vlan proto 802.1q id 10
ip link add link vlan10 vlan100 type vlan proto 802.1q id 100
ip link add link vlan100 type macvlan
Note: This patch limites the number of stacked VLANs to 2,
just like before. The original, however had another issue
in that if we had more then 2 levels of VLANs, we would end
up generating incorrectly tagged traffic. This is no longer
possible.
Fixes: fbd929f2dc (bonding: support QinQ for bond arp interval)
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@redhat.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Ding Tianhong <dingtianhong@huawei.com>
CC: Patric McHardy <kaber@trash.net>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit dc8eaaa006.
vlan: Fix lockdep warning when vlan dev handle notification
Instead we use the new new API to find the lock subclass of
our vlan device. This way we can support configurations where
vlans are interspersed with other devices:
bond -> vlan -> macvlan -> vlan
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently netif_addr_lock_nested assumes that there can be only
a single nesting level between 2 devices. However, if we
have multiple devices of the same type stacked, this fails.
For example:
eth0 <-- vlan0.10 <-- vlan0.10.20
A more complicated configuration may stack more then one type of
device in different order.
Ex:
eth0 <-- vlan0.10 <-- macvlan0 <-- vlan1.10.20 <-- macvlan1
This patch adds an ndo_* function that allows each stackable
device to report its nesting level. If the device doesn't
provide this function default subclass of 1 is used.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Multiple devices in the kernel can be stacked/nested and they
need to know their nesting level for the purposes of lockdep.
This patch provides a generic function that determines a nesting
level of a particular device by its type (ex: vlan, macvlan, etc).
We only care about nesting of the same type of devices.
For example:
eth0 <- vlan0.10 <- macvlan0 <- vlan1.20
The nesting level of vlan1.20 would be 1, since there is another vlan
in the stack under it.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds user-visible interfaces for the llsec infrastructure.
For the added methods, the only major difference between all add/remove
implementation lies in how the specific object is parsed, and for dump
requests, how objects are written into netlink messages.
To save on boilerplate code, table dumps are routed through a helper
function that handles netlink dump state, leaving the actual dumping
code to care only about iterating over the table to be dumped and
filling netlink messages. For add/remove methods, the boilerplate
required to work is not quite as large, but still enough to also move
into a local helper.
Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some Ethernet MACs have a "fixed link", and are not connected to a
normal MDIO-managed PHY device. For those situations, a Device Tree
binding allows to describe a "fixed link" using a special PHY node.
This patch adds:
* A documentation for the fixed PHY Device Tree binding.
* An of_phy_is_fixed_link() function that an Ethernet driver can call
on its PHY phandle to find out whether it's a fixed link PHY or
not. It should typically be used to know if
of_phy_register_fixed_link() should be called.
* An of_phy_register_fixed_link() function that instantiates the
fixed PHY into the PHY subsystem, so that when the driver calls
of_phy_connect(), the PHY device associated to the OF node will be
found.
These two additional functions also support the old fixed-link Device
Tree binding used on PowerPC platforms, so that ultimately, the
network device drivers for those platforms could be converted to use
of_phy_is_fixed_link() and of_phy_register_fixed_link() instead of
of_phy_connect_fixed_link(), while keeping compatibility with their
respective Device Tree bindings.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The existing fixed_phy_add() function has several drawbacks that
prevents it from being used as is for OF-based declaration of fixed
PHYs:
* The address of the PHY on the fake bus needs to be passed, while a
dynamic allocation is desired.
* Since the phy_device instantiation is post-poned until the next
mdiobus scan, there is no way to associate the fixed PHY with its
OF node, which later prevents of_phy_connect() from finding this
fixed PHY from a given OF node.
To solve this, this commit introduces fixed_phy_register(), which will
allocate an available PHY address, add the PHY using fixed_phy_add()
and instantiate the phy_device structure associated with the provided
OF node.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, some subsystems (e.g. PCI and the ACPI PM domain) have to
resume all runtime-suspended devices during system suspend, mostly
because those devices may need to be reprogrammed due to different
wakeup settings for system sleep and for runtime PM.
For some devices, though, it's OK to remain in runtime suspend
throughout a complete system suspend/resume cycle (if the device was in
runtime suspend at the start of the cycle). We would like to do this
whenever possible, to avoid the overhead of extra power-up and power-down
events.
However, problems may arise because the device's descendants may require
it to be at full power at various points during the cycle. Therefore the
most straightforward way to do this safely is if the device and all its
descendants can remain runtime suspended until the complete stage of
system resume.
To this end, introduce a new device PM flag, power.direct_complete
and modify the PM core to use that flag as follows.
If the ->prepare() callback of a device returns a positive number,
the PM core will regard that as an indication that it may leave the
device runtime-suspended. It will then check if the system power
transition in progress is a suspend (and not hibernation in particular)
and if the device is, indeed, runtime-suspended. In that case, the PM
core will set the device's power.direct_complete flag. Otherwise it
will clear power.direct_complete for the device and it also will later
clear it for the device's parent (if there's one).
Next, the PM core will not invoke the ->suspend() ->suspend_late(),
->suspend_irq(), ->resume_irq(), ->resume_early(), or ->resume()
callbacks for all devices having power.direct_complete set. It
will invoke their ->complete() callbacks, however, and those
callbacks are then responsible for resuming the devices as
appropriate, if necessary. For example, in some cases they may
need to queue up runtime resume requests for the devices using
pm_request_resume().
Changelog partly based on an Alan Stern's description of the idea
(http://marc.info/?l=linux-pm&m=139940466625569&w=2).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
This patch adds UPDATE_QP SRIOV wrapper support.
The mechanism is a general one, but currently only source MAC
index changes are allowed for VFs.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This eliminates a 1-bit left shift in every single caller,
and makes the inner loop of the CRC computation more efficient.
Renamed crc7 to crc7_be (big-endian) since the interface changed.
Also purged #include <linux/crc7.h> from files that don't use it at all.
Signed-off-by: George Spelvin <linux@horizon.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Implement css_tryget() which tries to grab a cgroup_subsys_state's
reference as long as it already hasn't reached zero. Combined with
the recent css iterator changes to include offline && !released csses
during traversal, this can be used to access csses regardless of its
online state.
v2: Take the new flag CSS_NO_REF into account.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Now that cgroup liveliness and css onliness are the same state,
convert cgroup_has_live_children() into css_has_online_children() so
that it can be used for actual csses too. The function now uses
css_for_each_child() for iteration and is published.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Use CSS_ONLINE on the self css to indicate whether a cgroup has been
killed instead of CGRP_DEAD. This will allow re-using css online test
for cgroup liveliness test. This doesn't introduce any functional
change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Currently, css_next_child() is implemented as finding the next child
cgroup which has the css enabled, which used to be the only way to do
it as only cgroups participated in sibling lists and thus could be
iteratd. This works as long as what's required during iteration is
not missing online csses; however, it turns out that there are use
cases where offlined but not yet released csses need to be iterated.
This is difficult to implement through cgroup iteration the unified
hierarchy as there may be multiple dying csses for the same subsystem
associated with single cgroup.
After the recent changes, the cgroup self and regular csses behave
identically in how they're linked and unlinked from the sibling lists
including assertion of CSS_RELEASED and css_next_child() can simply
switch to iterating csses directly. This both simplifies the logic
and ensures that all visible non-released csses are included in the
iteration whether there are multiple dying csses for a subsystem or
not.
As all other iterators depend on css_next_child() for sibling
iteration, this changes behaviors of all css iterators. Add and
update explanations on the css states which are included in traversal
to all iterators.
As css iteration could always contain offlined csses, this shouldn't
break any of the current users and new usages which need iteration of
all on and offline csses can make use of the new semantics.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
css iterations allow the caller to drop RCU read lock. As long as the
caller keeps the current position accessible, it can simply re-grab
RCU read lock later and continue iteration. This is achieved by using
CGRP_DEAD to detect whether the current positions next pointer is safe
to dereference and if not re-iterate from the beginning to the next
position using ->serial_nr.
CGRP_DEAD is used as the marker to invalidate the next pointer and the
only requirement is that the marker is set before the next sibling
starts its RCU grace period. Because CGRP_DEAD is set at the end of
cgroup_destroy_locked() but the cgroup is unlinked when the reference
count reaches zero, we currently have a rather large window where this
fallback re-iteration logic can be triggered.
This patch introduces CSS_RELEASED which is set when a css is unlinked
from its sibling list. This still keeps the re-iteration logic
working while drastically reducing the window of its activation.
While at it, rewrite the comment in css_next_child() to reflect the
new flag and better explain the synchronization.
This will also enable iterating csses directly instead of through
cgroups.
v2: CSS_RELEASED now assigned to 1 << 2 as 1 << 0 is used by
CSS_NO_REF.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
We're moving towards using cgroup_subsys_states as the fundamental
structural blocks. All csses including the cgroup->self and actual
ones now form trees through css->children and ->sibling which follow
the same rules as what cgroup->children and ->sibling followed. This
patch moves cgroup->serial_nr which is used to implement css iteration
into css.
Note that all csses, regardless of their types, allocate their serial
numbers from the same monotonically increasing counter. This doesn't
affect the ordering needed by css iteration or cause any other
material behavior changes. This will be used to update css iteration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
We're moving towards using cgroup_subsys_states as the fundamental
structural blocks. Let's move cgroup->sibling and ->children into
cgroup_subsys_state. This is pure move without functional change and
only cgroup->self's fields are actually used. Other csses will make
use of the fields later.
While at it, update init_and_link_css() so that it zeroes the whole
css before initializing it and remove explicit zeroing of ->flags.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup->parent is redundant as cgroup->self.parent can also be used to
determine the parent cgroup and we're moving towards using
cgroup_subsys_states as the fundamental structural blocks. This patch
introduces cgroup_parent() which follows cgroup->self.parent and
removes cgroup->parent.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup in general is moving towards using cgroup_subsys_state as the
fundamental structural component and css_parent() was introduced to
convert from using cgroup->parent to css->parent. It was quite some
time ago and we're moving forward with making css more prominent.
This patch drops the trivial wrapper css_parent() and let the users
dereference css->parent. While at it, explicitly mark fields of css
which are public and immutable.
v2: New usage from device_cgroup.c converted.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Johannes Weiner <hannes@cmpxchg.org>
9395a45004 ("cgroup: enable refcnting for root csses") enabled
reference counting for root csses (cgroup_subsys_states) so that
cgroup's self csses can be used to manage the lifetime of the
containing cgroups.
Unfortunately, this change was incorrect. During early init,
cgrp_dfl_root self css refcnt is used. percpu_ref can't initialized
during early init and its initialization is deferred till
cgroup_init() time. This means that cpu was using percpu_ref which
wasn't properly initialized. Due to the way percpu variables are laid
out on x86, this didn't blow up immediately on x86 but ended up
incrementing and decrementing the percpu variable at offset zero,
whatever it may be; however, on other archs, this caused fault and
early boot failure.
As cgroup self csses for root cgroups of non-dfl hierarchies need
working refcounting, we can't revert 9395a45004. This patch adds
CSS_NO_REF which explicitly inhibits reference counting on the css and
sets it on all normal (non-self) csses and cgroup_dfl_root self css.
v2: cgrp_dfl_root.self is the offending one. Set the flag on it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Fixes: 9395a45004 ("cgroup: enable refcnting for root csses")
Today's linux-next kernel started showing build errors for the
use of WARN_ON in linux/gpio/consumer.h:
In file included from drivers/video/backlight/pwm_bl.c:13:0:
include/linux/gpio/consumer.h: In function 'gpiod_put':
include/linux/gpio/consumer.h:81:2: error: implicit declaration of function 'WARN_ON' [-Werror=implicit-function-declaration]
It's not clear why this never happened before, but this patch
fixes it by including the header that contains the defintion
of this macro.
Signed-off-by: Arnd Bergmann <arnd@arnd.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
