Paul E. McKenney [Tue, 24 Jan 2012 01:23:35 +0000 (17:23 -0800)]
rcu: No interrupt disabling for rcu_prepare_for_idle()
The rcu_prepare_for_idle() function is always called with interrupts
disabled, so there is no reason to disable interrupts again within
rcu_prepare_for_idle(). Therefore, this commit removes all of the
interrupt disabling, also removing a latent disabling-unbalance bug.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 24 Jan 2012 01:05:46 +0000 (17:05 -0800)]
rcu: Move synchronize_sched_expedited() to rcutree.c
Now that TREE_RCU and TREE_PREEMPT_RCU no longer do anything different
for the single-CPU case, there is no need for multiple definitions of
synchronize_sched_expedited(). It is no longer in any sense a plug-in,
so move it from kernel/rcutree_plugin.h to kernel/rcutree.c.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Mon, 23 Jan 2012 20:41:26 +0000 (12:41 -0800)]
rcu: Check for illegal use of RCU from offlined CPUs
Although it is legal to use RCU during early boot, it is anything
but legal to use RCU at runtime from an offlined CPU. After all, RCU
explicitly ignores offlined CPUs. This commit therefore adds checks
for runtime use of RCU from offlined CPUs.
These checks are not perfect, in particular, they can be subverted
through use of things like rcu_dereference_raw(). Note that it is not
possible to put checks in rcu_read_lock() and friends due to the fact
that these primitives are used in code that might be used under either
RCU or lock-based protection, which means that checking rcu_read_lock()
gets you fat piles of false positives.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Sat, 21 Jan 2012 01:35:55 +0000 (17:35 -0800)]
rcu: Update stall-warning documentation
Add documentation of CONFIG_RCU_CPU_STALL_VERBOSE, CONFIG_RCU_CPU_STALL_INFO,
and RCU_STALL_DELAY_DELTA. Describe multiple stall-warning messages from
a single stall, and the timing of the subsequent messages. Add headings.
Remove RCU_SECONDS_TILL_STALL_RECHECK because this value is now computed
at runtime from RCU_CPU_STALL_TIMEOUT, so that sysfs changes to the timeout
value now directly affect the RCU_SECONDS_TILL_STALL_RECHECK value.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Fri, 20 Jan 2012 23:36:33 +0000 (15:36 -0800)]
rcu: Add CPU-stall capability to rcutorture
Add module parameters to rcutorture that induce a CPU stall.
The stall_cpu parameter specifies how long to stall in seconds,
defaulting to zero, which indicates no stalling is to be undertaken.
The stall_cpu_holdoff parameter specifies how many seconds after
insmod (or boot, if rcutorture is built into the kernel) that this
stall is to start. The default value for stall_cpu_holdoff is ten
seconds.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Make documentation give more realistic rcutorture duration
The torture.txt documentation gives an example rcutorture run with a
100-second duration. This is ridiculously short, unless maybe testing
a fix for a egregious bug. Use a more-realistic one-hour duration for
the example.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 17 Jan 2012 22:36:51 +0000 (14:36 -0800)]
rcutorture: Permit holding off CPU-hotplug operations during boot
When rcutorture is started automatically at boot time, it might well
also start CPU-hotplug operations at that time, which might not be
desirable. This commit therefore adds an rcutorture parameter that
allows CPU-hotplug operations to be held off for the specified number
of seconds after the start of boot.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Mon, 16 Jan 2012 21:29:10 +0000 (13:29 -0800)]
rcu: Print scheduling-clock information on RCU CPU stall-warning messages
There have been situations where RCU CPU stall warnings were caused by
issues in scheduling-clock timer initialization. To make it easier to
track these down, this commit causes the RCU CPU stall-warning messages
to print out the number of scheduling-clock interrupts taken in the
current grace period for each stalled CPU.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Fri, 13 Jan 2012 23:32:18 +0000 (15:32 -0800)]
rcu: Set RCU CPU stall times via sysfs
The default CONFIG_RCU_CPU_STALL_TIMEOUT value of 60 seconds has served
Linux users well for production use for quite some time. However, for
debugging, there will be more than three minutes between subsequent
stall-warning messages. This can be an annoyingly long wait if you
are trying to work out where the offending infinite loop is hiding.
Therefore, this commit provides a rcu_cpu_stall_timeout sysfs
parameter that may be adjusted at boot time and at runtime to speed
up debugging.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Fri, 13 Jan 2012 03:35:08 +0000 (19:35 -0800)]
rcu: Remove #ifdef CONFIG_SMP from TREE_RCU
Now that both TINY_RCU and TINY_PREEMPT_RCU have been in place for awhile,
it is time to remove UP support from TREE_RCU, which is what this commit
does.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Fri, 13 Jan 2012 01:21:20 +0000 (17:21 -0800)]
rcu: Note that rcu_access_pointer() can be used for teardown
There is no convenient expression for rcu_deference_protected()
when it is used in tearing down multilinked structures following
a grace period. For example, suppose that an element containing an
RCU-protected pointer to a second element is removed from an enclosing
RCU-protected data structure, then the write-side lock is released,
and finally synchronize_rcu() is invoked to wait for a grace period.
Then it is necessary to traverse the pointer in order to free up the
second element. But we are not in an RCU read-side critical section
and we are holding no locks, so the usual rcu_dereference_check() and
rcu_dereference_protected() primitives are not appropriate. Neither
is rcu_dereference_raw(), as it is intended for use in data structures
where the user defines the locking design (for example, list_head).
So this responsibility is added to rcu_access_pointer()'s list, and
this commit updates rcu_assign_pointer()'s header comment accordingly.
Suggested-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com>
Paul E. McKenney [Thu, 12 Jan 2012 21:49:19 +0000 (13:49 -0800)]
rcu: Make rcu_sleep_check() also check rcu_lock_map
Although it is OK to be preempted in an RCU read-side critical section
for TREE_PREEMPT_RCU, it is definitely not OK to be preempted, block,
or might_sleep() within an RCU read-side critical section for TREE_RCU.
Unfortunately, rcu_might_sleep() currently only checks for RCU-bh and
RCU-sched read-side critical sections. This commit therefore makes
rcu_might_sleep() check for RCU read-side critical sections, but only
in TREE_RCU builds.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 12 Jan 2012 21:08:18 +0000 (13:08 -0800)]
rcu: Check for idle-loop entry while in RCU read-side critical section
The inner idle loop is an extended quiescent state for all flavors
of RCU, but there have been recent bug involving use of RCU read-side
primitives from within the idle loop. Therefore, this commit enlists
lockdep-RCU to detect attempts to enter the inner idle loop while in
an RCU read-side critical section, emitting a lockdep-RCU splat if so.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 12 Jan 2012 19:01:14 +0000 (11:01 -0800)]
rcu: Clean up straggling rcu_preempt_needs_cpu() name
The recent updates to RCU_CPU_FAST_NO_HZ have an rcu_needs_cpu() that
does more than just check for callbacks, so get the name for
rcu_preempt_needs_cpu() consistent with that change, now calling it
rcu_preempt_cpu_has_callbacks().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 12 Jan 2012 01:25:17 +0000 (17:25 -0800)]
rcu: Simplify unboosting checks
This is a port of commit #82e78d80 from TREE_PREEMPT_RCU to
TINY_PREEMPT_RCU.
This commit uses the fact that current->rcu_boost_mutex is set
any time that the RCU_READ_UNLOCK_BOOSTED flag is set in the
current->rcu_read_unlock_special bitmask. This allows tests of
the bit to be changed to tests of the pointer, which in turn allows
the RCU_READ_UNLOCK_BOOSTED flag to be eliminated.
Please note that the check of current->rcu_read_unlock_special need not
change because any time that RCU_READ_UNLOCK_BOOSTED was set, so was
RCU_READ_UNLOCK_BLOCKED. Therefore, __rcu_read_unlock() can continue
testing current->rcu_read_unlock_special for non-zero, as before.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 12 Jan 2012 00:59:01 +0000 (16:59 -0800)]
rcu: Inform RCU of irq_exit() activity
This is a port to TINY_RCU of Peter Zijlstra's commit #ec433f0c5
The rcu_read_unlock_special() function relies on in_irq() to exclude
scheduler activity from interrupt level. This fails because exit_irq()
can invoke the scheduler after clearing the preempt_count() bits that
in_irq() uses to determine that it is at interrupt level. This situation
can result in failures as follows:
$task IRQ SoftIRQ
rcu_read_lock()
/* do stuff */
<preempt> |= UNLOCK_BLOCKED
rcu_read_unlock()
--t->rcu_read_lock_nesting
irq_enter();
/* do stuff, don't use RCU */
irq_exit();
sub_preempt_count(IRQ_EXIT_OFFSET);
invoke_softirq()
This can be triggered 'easily' because invoke_softirq() immediately does
a ttwu() of ksoftirqd/# instead of doing the in-place softirq stuff first,
but even without that the above happens.
Cure this by also excluding softirqs from the rcu_read_unlock_special()
handler and ensuring the force_irqthreads ksoftirqd/# wakeup is done
from full softirq context.
It is also necessary to delay the ->rcu_read_lock_nesting decrement until
after rcu_read_unlock_special(). This delay is handled by the commit
"Protect __rcu_read_unlock() against scheduler-using irq handlers".
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 12 Jan 2012 00:33:17 +0000 (16:33 -0800)]
rcu: Prevent RCU callbacks from executing before scheduler initialized
This is a port of commit #b0d3041 from TREE_RCU to TREE_PREEMPT_RCU.
Under some rare but real combinations of configuration parameters, RCU
callbacks are posted during early boot that use kernel facilities that are
not yet initialized. Therefore, when these callbacks are invoked, hard
hangs and crashes ensue. This commit therefore prevents RCU callbacks
from being invoked until after the scheduler is fully up and running,
as in after multiple tasks have been spawned.
It might well turn out that a better approach is to identify the specific
RCU callbacks that are causing this problem, but that discussion will
wait until such time as someone really needs an RCU callback to be invoked
(as opposed to merely registered) during early boot.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Wed, 11 Jan 2012 23:30:36 +0000 (15:30 -0800)]
rcu: Streamline code produced by __rcu_read_unlock()
This is a port of commit #be0e1e21 to TINY_PREEMPT_RCU. This uses
noinline to prevent rcu_read_unlock_special() from being inlined into
__rcu_read_unlock().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Wed, 11 Jan 2012 22:40:20 +0000 (14:40 -0800)]
rcu: Protect __rcu_read_unlock() against scheduler-using irq handlers
This commit ports commit #10f39bb1b2 (rcu: protect __rcu_read_unlock()
against scheduler-using irq handlers) from TREE_PREEMPT_RCU to
TINY_PREEMPT_RCU. The following is a corresponding port of that
commit message.
The addition of RCU read-side critical sections within runqueue and
priority-inheritance critical sections introduced some deadlocks,
for example, involving interrupts from __rcu_read_unlock() where the
interrupt handlers call wake_up(). This situation can cause the
instance of __rcu_read_unlock() invoked from interrupt to do some
of the processing that would otherwise have been carried out by the
task-level instance of __rcu_read_unlock(). When the interrupt-level
instance of __rcu_read_unlock() is called with a scheduler lock held from
interrupt-entry/exit situations where in_irq() returns false, deadlock can
result. Of course, in a UP kernel, there are not really any deadlocks,
but the upper-level critical section can still be be fatally confused
by the lower-level critical section changing things out from under it.
This commit resolves these deadlocks by using negative values of the
per-task ->rcu_read_lock_nesting counter to indicate that an instance of
__rcu_read_unlock() is in flight, which in turn prevents instances from
interrupt handlers from doing any special processing. Note that nested
rcu_read_lock()/rcu_read_unlock() pairs are still permitted, but they will
never see ->rcu_read_lock_nesting go to zero, and will therefore never
invoke rcu_read_unlock_special(), thus preventing them from seeing the
RCU_READ_UNLOCK_BLOCKED bit should it be set in ->rcu_read_unlock_special.
This patch also adds a check for ->rcu_read_unlock_special being negative
in rcu_check_callbacks(), thus preventing the RCU_READ_UNLOCK_NEED_QS
bit from being set should a scheduling-clock interrupt occur while
__rcu_read_unlock() is exiting from an outermost RCU read-side critical
section.
Of course, __rcu_read_unlock() can be preempted during the time that
->rcu_read_lock_nesting is negative. This could result in the setting
of the RCU_READ_UNLOCK_BLOCKED bit after __rcu_read_unlock() checks it,
and would also result it this task being queued on the corresponding
rcu_node structure's blkd_tasks list. Therefore, some later RCU read-side
critical section would enter rcu_read_unlock_special() to clean up --
which could result in deadlock (OK, OK, fatal confusion) if that RCU
read-side critical section happened to be in the scheduler where the
runqueue or priority-inheritance locks were held.
To prevent the possibility of fatal confusion that might result from
preemption during the time that ->rcu_read_lock_nesting is negative,
this commit also makes rcu_preempt_note_context_switch() check for
negative ->rcu_read_lock_nesting, thus refraining from queuing the task
(and from setting RCU_READ_UNLOCK_BLOCKED) if we are already exiting
from the outermost RCU read-side critical section (in other words,
we really are no longer actually in that RCU read-side critical
section). In addition, rcu_preempt_note_context_switch() invokes
rcu_read_unlock_special() to carry out the cleanup in this case, which
clears out the ->rcu_read_unlock_special bits and dequeues the task
(if necessary), in turn avoiding needless delay of the current RCU grace
period and needless RCU priority boosting.
It is still illegal to call rcu_read_unlock() while holding a scheduler
lock if the prior RCU read-side critical section has ever had both
preemption and irqs enabled. However, the common use case is legal,
namely where then entire RCU read-side critical section executes with
irqs disabled, for example, when the scheduler lock is held across the
entire lifetime of the RCU read-side critical section.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Wed, 11 Jan 2012 19:34:50 +0000 (11:34 -0800)]
rcu: Remove single-rcu_node optimization in rcu_start_gp()
The grace-period initialization sequence in rcu_start_gp() has a special
case for systems where the rcu_node tree is a single rcu_node structure.
This made sense some years ago when systems were smaller and up to 64
CPUs could share a single rcu_node structure, but now that large systems
are common and a given leaf rcu_node structure can support only 16 CPUs
(due to lock contention on the rcu_node's ->lock field), this optimization
is almost never taken. And even the small mobile platforms that might
make use of it might rather have the kernel text reduction.
Therefore, this commit removes the check for single-rcu_node trees.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 11 Jan 2012 01:52:31 +0000 (17:52 -0800)]
rcu: Don't make callbacks go through second full grace period
RCU's current CPU-offline code path dumps all of the outgoing CPU's
callbacks onto the RCU_NEXT_TAIL portion of the surviving CPU's
callback list. This means that all the ready-to-invoke callbacks from
the outgoing CPU must wait for another full RCU grace period. This was
just fine when CPU-hotplug events were rare, but there is increasing
evidence that users are planning to make increasing use of CPU hotplug.
Therefore, this commit changes the callback-dumping procedure so that
callbacks that are ready to invoke are moved to the RCU_DONE_TAIL
portion of the surviving CPU's callback list. This avoids running
these callbacks through a second unnecessary grace period.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 10 Jan 2012 22:23:29 +0000 (14:23 -0800)]
rcu: Check for callback invocation from offline CPUs
Because quiescent states are now reported from offline CPUs in
CPU_DYING state, there is some possibility that such a CPU might
note the end of a grace period and attempt to start invoking
callbacks. This would be a very bad thing, and is supposed to
be prevented by the fact that the CPU_DYING CPU gets rid of all
its callbacks before reporting the quiescent state. However,
there is other CPU-offline code in the kernel, and it is quite
possible that someone will invoke RCU core processing from that
code. Therefore, this commit adds a warning for this case.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 10 Jan 2012 22:13:24 +0000 (14:13 -0800)]
rcu: Limit lazy-callback duration
Currently, a given CPU is permitted to remain in dyntick-idle mode
indefinitely if it has only lazy RCU callbacks queued. This is vulnerable
to corner cases in NUMA systems, so limit the time to six seconds by
default. (Currently controlled by a cpp macro.)
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Move ->qsmaskinit and blkd_tasks[] manipulation to the CPU_DYING
notifier. This simplifies the code by eliminating a potential
deadlock and by reducing the responsibilities of force_quiescent_state().
Also rename functions to make their connection to the CPU-hotplug
stages explicit.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
mac80211: Convert call_rcu() to kfree_rcu(), drop mesh_gate_node_reclaim()
The call_rcu() in mesh_gate_del() invokes mesh_gate_node_reclaim(),
which simply calls kfree(). So convert the call_rcu() to kfree_rcu(),
allowing mesh_gate_node_reclaim() to be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org
ipv4: Convert call_rcu() to kfree_rcu(), drop opt_kfree_rcu
The call_rcu() in do_ip_setsockopt() invokes opt_kfree_rcu(), which just
calls kfree(). So convert the call_rcu() to kfree_rcu(), which allows
opt_kfree_rcu() to be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: 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> Cc: netdev@vger.kernel.org
ipv4: Convert call_rcu() to kfree_rcu(), drop opt_kfree_rcu()
Because opt_kfree_rcu() just calls kfree(), all call_rcu() uses of it
may be converted to kfree_rcu(). This permits opt_kfree_rcu() to
be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: 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> Cc: netdev@vger.kernel.org
tcm_fc: Convert call_rcu() to kfree_rcu(), drop ft_tport_rcu_free()
The call_rcu() in ft_tport_delete() invokes ft_tport_rcu_free(),
which just does a kfree(). So convert the call_rcu() to kfree_rcu(),
allowing ft_tport_rcu_free() to be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jesper Juhl <jj@chaosbits.net> Cc: linux-scsi@vger.kernel.org Cc: target-devel@vger.kernel.org
s390: Convert call_rcu() to kfree_rcu(), drop ext_int_hash_update()
The call_rcu() in unregister_external_interrupt() invokes
ext_int_hash_update(), which just does a kfree(). Convert the
call_rcu() to kfree_rcu(), allowing ext_int_hash_update() to
be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
The RCU_TRACE kernel parameter has always been intended for debugging,
not for production use. Formalize this by moving RCU_TRACE from
init/Kconfig to lib/Kconfig.debug.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Avoid waking up CPUs having only kfree_rcu() callbacks
When CONFIG_RCU_FAST_NO_HZ is enabled, RCU will allow a given CPU to
enter dyntick-idle mode even if it still has RCU callbacks queued.
RCU avoids system hangs in this case by scheduling a timer for several
jiffies in the future. However, if all of the callbacks on that CPU
are from kfree_rcu(), there is no reason to wake the CPU up, as it is
not a problem to defer freeing of memory.
This commit therefore tracks the number of callbacks on a given CPU
that are from kfree_rcu(), and avoids scheduling the timer if all of
a given CPU's callbacks are from kfree_rcu().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Add diagnostic for misaligned rcu_head structures
The push for energy efficiency will require that RCU tag rcu_head
structures to indicate whether or not their invocation is time critical.
This tagging is best carried out in the bottom bits of the ->next
pointers in the rcu_head structures. This tagging requires that the
rcu_head structures be properly aligned, so this commit adds the required
diagnostics.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Add lockdep-RCU checks for simple self-deadlock
It is illegal to have a grace period within a same-flavor RCU read-side
critical section, so this commit adds lockdep-RCU checks to splat when
such abuse is encountered. This commit does not detect more elaborate
RCU deadlock situations. These situations might be a job for lockdep
enhancements.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although TREE_PREEMPT_RCU indirectly uses might_sleep() to detect illegal
use of synchronize_sched() and synchronize_rcu_bh() from within an RCU
read-side critical section, this might_sleep() check is bypassed when
there is only a single CPU (for example, when running an SMP kernel on
a single-CPU system). This patch therefore adds a might_sleep() call
to the rcu_blocking_is_gp() check that is unconditionally invoked from
both synchronize_sched() and synchronize_rcu_bh().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Linus Torvalds [Sat, 18 Feb 2012 23:40:00 +0000 (15:40 -0800)]
Merge tag 'fixes-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
These are the bug fixes that have accumulated since 3.3-rc3 in arm-soc.
The majority of them are regression fixes for stuff that broke during
the merge 3.3 window.
The notable ones are:
* The at91 ata drivers both broke because of an earlier cleanup patch that
some other patches were based on. Jean-Christophe decided to remove
the legacy at91_ide driver and fix the new-style at91-pata driver while
keeping the cleanup patch. I almost rejected the patches for being too
late and too big but in the end decided to accept them because they
fix a regression.
* A patch fixing build breakage from the sysdev-to-device conversion
colliding with other changes touches a number of mach-s3c files.
* b0654037 "ARM: orion: Fix Orion5x GPIO regression from MPP cleanup"
is a mechanical change that unfortunately touches a lot of lines
that should up in the diffstat.
* tag 'fixes-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (28 commits)
ARM: at91: drop ide driver in favor of the pata one
pata/at91: use newly introduced SMC accessors
ARM: at91: add accessor to manage SMC
ARM: at91:rtc/rtc-at91sam9: ioremap register bank
ARM: at91: USB AT91 gadget registration for module
ep93xx: fix build of vision_ep93xx.c
ARM: OMAP2xxx: PM: fix OMAP2xxx-specific UART idle bug in v3.3
ARM: orion: Fix USB phy for orion5x.
ARM: orion: Fix Orion5x GPIO regression from MPP cleanup
ARM: EXYNOS: Add cpu-offset property in gic device tree node
ARM: EXYNOS: Bring exynos4-dt up to date
ARM: OMAP3: cm-t35: fix section mismatch warning
ARM: OMAP2: Fix the OMAP2 only build break seen with 2011+ ARM tool-chains
ARM: tegra: paz00: fix wrong UART port on mini-pcie plug
ARM: tegra: paz00: fix wrong SD1 power gpio
i2c: tegra: Add devexit_p() for remove
ARM: EXYNOS: Correct M-5MOLS sensor clock frequency on Universal C210 board
ARM: EXYNOS: Correct framebuffer window size on Nuri board
ARM: SAMSUNG: Fix missing api-change from subsys_interface change
ARM: EXYNOS: Fix "warning: initialization from incompatible pointer type"
...
1) VETH_INFO_PEER netlink attribute needs to have it's size validated,
from Thomas Graf.
2) 'poll' module option of bnx2x driver crashes the machine, just remove
it. From Michal Schmidt.
3) ks8851_mll driver reads the irq number from two places, but only
initializes one of them, oops. Use only one location and fix this
problem, from Jan Weitzel.
4) Fix buffer overrun and unicast sterring bugs in mellanox mlx4 driver,
from Eugenia Emantayev.
5) Swapped kcalloc() args in RxRPC and mlx4, from Axel Lin.
6) PHY MDIO device name regression fixes from Florian Fainelli.
7) If the wake event IRQ line is different from the netdevice one, we
have to properly route it to the stmmac interrupt handler. From
Francesco Virlinzi.
8) Fix rwlock lock initialization ordering bug in mac80211, from
Mohammed Shafi Shajakhan.
9) TCP lost_cnt can get out of sync, and in fact go negative, in certain
circumstances. Fix the way we specify what sequence range to operate
on in tcp_sacktag_one() to fix this bug. From Neal Cardwell.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
net/ethernet: ks8851_mll fix irq handling
veth: Enforce minimum size of VETH_INFO_PEER
stmmac: update the driver version to Feb 2012 (v2)
stmmac: move hw init in the probe (v2)
stmmac: request_irq when use an ext wake irq line (v2)
stmmac: do not discard frame on dribbling bit assert
ipheth: Add iPhone 4S
mlx4: add unicast steering entries to resource_tracker
mlx4: fix QP tree trashing
mlx4: fix buffer overrun
3c59x: shorten timer period for slave devices
netpoll: netpoll_poll_dev() should access dev->flags
RxRPC: Fix kcalloc parameters swapped
bnx2x: remove the 'poll' module option
tcp: fix tcp_shifted_skb() adjustment of lost_cnt_hint for FACK
ks8851: Fix NOHZ local_softirq_pending 08 warning
bnx2x: fix bnx2x_storm_stats_update() on big endian
ixp4xx-eth: fix PHY name to match MDIO bus name
octeon: fix PHY name to match MDIO bus name
fec: fix PHY name to match fixed MDIO bus name
...
Linus Torvalds [Sat, 18 Feb 2012 23:37:25 +0000 (15:37 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Fixes a bootstrapping issue for some registers when a less commonly used
method for register cache initialisation is used. Only affects a fairly
small proportion of users that both don't use explicit register defaults
and do use the cache.
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: Fix cache defaults initialization from raw cache defaults
Linus Torvalds [Sat, 18 Feb 2012 23:28:56 +0000 (15:28 -0800)]
Merge tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Fixes maximum filename length and filesystem type reporting in statfs() calls
and also fixes stale inode mode bits on eCryptfs inodes after a POSIX ACL was
set on the lower filesystem's inode.
* tag 'ecryptfs-3.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
ecryptfs: remove the second argument of k[un]map_atomic()
eCryptfs: Copy up lower inode attrs after setting lower xattr
eCryptfs: Improve statfs reporting
Linus Torvalds [Sat, 18 Feb 2012 23:26:37 +0000 (15:26 -0800)]
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Here are a few more fixes for powerpc. Some are regressions, the rest
is simple/obvious/nasty enough that I deemed it good to go now.
Here's also step one of deprecating legacy iSeries support: we are
removing it from the main defconfig.
Nobody seems to be using it anymore and the code is nasty to maintain,
(involves horrible hacks in various low level areas of the kernel) so we
plan to actually rip it out at some point. For now let's just avoid
building it by default. Stephen will proceed to do the actual removal
later (probably 3.4 or 3.5).
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
powerpc/adb: Use set_current_state()
powerpc: Disable interrupts early in Program Check
powerpc: Remove legacy iSeries from ppc64_defconfig
powerpc/fsl/pci: Fix PCIe fixup regression
powerpc: Fix kernel log of oops/panic instruction dump
Linus Torvalds [Sat, 18 Feb 2012 23:26:11 +0000 (15:26 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
One regression fix for SR-IOV on PPC and a couple of misc fixes from
Yinghai.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci:
PCI: Fix pci cardbus removal
PCI: set pci sriov page size before reading SRIOV BAR
PCI: workaround hard-wired bus number V2
Linus Torvalds [Sat, 18 Feb 2012 23:25:39 +0000 (15:25 -0800)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
3 radeon fixes, I have some exynos fixes to push later but I'll queue
them separately once I've looked them over a bit.
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/radeon/kms: fix MSI re-arm on rv370+
drm/radeon/kms/atom: bios scratch reg handling updates
drm/radeon/kms: drop lock in return path of radeon_fence_count_emitted.
Linus Torvalds [Sat, 18 Feb 2012 20:56:35 +0000 (12:56 -0800)]
i387: re-introduce FPU state preloading at context switch time
After all the FPU state cleanups and finally finding the problem that
caused all our FPU save/restore problems, this re-introduces the
preloading of FPU state that was removed in commit b3b0870ef3ff ("i387:
do not preload FPU state at task switch time").
However, instead of simply reverting the removal, this reimplements
preloading with several fixes, most notably
- properly abstracted as a true FPU state switch, rather than as
open-coded save and restore with various hacks.
In particular, implementing it as a proper FPU state switch allows us
to optimize the CR0.TS flag accesses: there is no reason to set the
TS bit only to then almost immediately clear it again. CR0 accesses
are quite slow and expensive, don't flip the bit back and forth for
no good reason.
- Make sure that the same model works for both x86-32 and x86-64, so
that there are no gratuitous differences between the two due to the
way they save and restore segment state differently due to
architectural differences that really don't matter to the FPU state.
- Avoid exposing the "preload" state to the context switch routines,
and in particular allow the concept of lazy state restore: if nothing
else has used the FPU in the meantime, and the process is still on
the same CPU, we can avoid restoring state from memory entirely, just
re-expose the state that is still in the FPU unit.
That optimized lazy restore isn't actually implemented here, but the
infrastructure is set up for it. Of course, older CPU's that use
'fnsave' to save the state cannot take advantage of this, since the
state saving also trashes the state.
In other words, there is now an actual _design_ to the FPU state saving,
rather than just random historical baggage. Hopefully it's easier to
follow as a result.
Linus Torvalds [Sat, 18 Feb 2012 05:48:54 +0000 (21:48 -0800)]
i387: move TS_USEDFPU flag from thread_info to task_struct
This moves the bit that indicates whether a thread has ownership of the
FPU from the TS_USEDFPU bit in thread_info->status to a word of its own
(called 'has_fpu') in task_struct->thread.has_fpu.
This fixes two independent bugs at the same time:
- changing 'thread_info->status' from the scheduler causes nasty
problems for the other users of that variable, since it is defined to
be thread-synchronous (that's what the "TS_" part of the naming was
supposed to indicate).
So perfectly valid code could (and did) do
ti->status |= TS_RESTORE_SIGMASK;
and the compiler was free to do that as separate load, or and store
instructions. Which can cause problems with preemption, since a task
switch could happen in between, and change the TS_USEDFPU bit. The
change to TS_USEDFPU would be overwritten by the final store.
In practice, this seldom happened, though, because the 'status' field
was seldom used more than once, so gcc would generally tend to
generate code that used a read-modify-write instruction and thus
happened to avoid this problem - RMW instructions are naturally low
fat and preemption-safe.
- On x86-32, the current_thread_info() pointer would, during interrupts
and softirqs, point to a *copy* of the real thread_info, because
x86-32 uses %esp to calculate the thread_info address, and thus the
separate irq (and softirq) stacks would cause these kinds of odd
thread_info copy aliases.
This is normally not a problem, since interrupts aren't supposed to
look at thread information anyway (what thread is running at
interrupt time really isn't very well-defined), but it confused the
heck out of irq_fpu_usable() and the code that tried to squirrel
away the FPU state.
(It also caused untold confusion for us poor kernel developers).
It also turns out that using 'task_struct' is actually much more natural
for most of the call sites that care about the FPU state, since they
tend to work with the task struct for other reasons anyway (ie
scheduling). And the FPU data that we are going to save/restore is
found there too.
Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to
the %esp issue.
Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: Raphael Prevost <raphael@buro.asia> Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Fri, 17 Feb 2012 03:11:15 +0000 (19:11 -0800)]
i387: move AMD K7/K8 fpu fxsave/fxrstor workaround from save to restore
The AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is
pending. In order to not leak FIP state from one process to another, we
need to do a floating point load after the fxsave of the old process,
and before the fxrstor of the new FPU state. That resets the state to
the (uninteresting) kernel load, rather than some potentially sensitive
user information.
We used to do this directly after the FPU state save, but that is
actually very inconvenient, since it
(a) corrupts what is potentially perfectly good FPU state that we might
want to lazy avoid restoring later and
(b) on x86-64 it resulted in a very annoying ordering constraint, where
"__unlazy_fpu()" in the task switch needs to be delayed until after
the DS segment has been reloaded just to get the new DS value.
Coupling it to the fxrstor instead of the fxsave automatically avoids
both of these issues, and also ensures that we only do it when actually
necessary (the FP state after a save may never actually get used). It's
simply a much more natural place for the leaked state cleanup.
Linus Torvalds [Thu, 16 Feb 2012 23:45:23 +0000 (15:45 -0800)]
i387: do not preload FPU state at task switch time
Yes, taking the trap to re-load the FPU/MMX state is expensive, but so
is spending several days looking for a bug in the state save/restore
code. And the preload code has some rather subtle interactions with
both paravirtualization support and segment state restore, so it's not
nearly as simple as it should be.
Also, now that we no longer necessarily depend on a single bit (ie
TS_USEDFPU) for keeping track of the state of the FPU, we migth be able
to do better. If we are really switching between two processes that
keep touching the FP state, save/restore is inevitable, but in the case
of having one process that does most of the FPU usage, we may actually
be able to do much better than the preloading.
In particular, we may be able to keep track of which CPU the process ran
on last, and also per CPU keep track of which process' FP state that CPU
has. For modern CPU's that don't destroy the FPU contents on save time,
that would allow us to do a lazy restore by just re-enabling the
existing FPU state - with no restore cost at all!
Tyler Hicks [Tue, 7 Feb 2012 23:55:40 +0000 (17:55 -0600)]
eCryptfs: Copy up lower inode attrs after setting lower xattr
After passing through a ->setxattr() call, eCryptfs needs to copy the
inode attributes from the lower inode to the eCryptfs inode, as they
may have changed in the lower filesystem's ->setxattr() path.
One example is if an extended attribute containing a POSIX Access
Control List is being set. The new ACL may cause the lower filesystem to
modify the mode of the lower inode and the eCryptfs inode would need to
be updated to reflect the new mode.
Tyler Hicks [Sat, 5 Nov 2011 17:45:08 +0000 (13:45 -0400)]
eCryptfs: Improve statfs reporting
statfs() calls on eCryptfs files returned the wrong filesystem type and,
when using filename encryption, the wrong maximum filename length.
If mount-wide filename encryption is enabled, the cipher block size and
the lower filesystem's max filename length will determine the max
eCryptfs filename length. Pre-tested, known good lengths are used when
the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte
block sizes is used. In other, less common cases, we fall back to a safe
rounded-down estimate when determining the eCryptfs namelen.
Linus Torvalds [Thu, 16 Feb 2012 21:33:12 +0000 (13:33 -0800)]
i387: don't ever touch TS_USEDFPU directly, use helper functions
This creates three helper functions that do the TS_USEDFPU accesses, and
makes everybody that used to do it by hand use those helpers instead.
In addition, there's a couple of helper functions for the "change both
CR0.TS and TS_USEDFPU at the same time" case, and the places that do
that together have been changed to use those. That means that we have
fewer random places that open-code this situation.
The intent is partly to clarify the code without actually changing any
semantics yet (since we clearly still have some hard to reproduce bug in
this area), but also to make it much easier to use another approach
entirely to caching the CR0.TS bit for software accesses.
Right now we use a bit in the thread-info 'status' variable (this patch
does not change that), but we might want to make it a full field of its
own or even make it a per-cpu variable.
Linus Torvalds [Thu, 16 Feb 2012 20:22:48 +0000 (12:22 -0800)]
i387: move TS_USEDFPU clearing out of __save_init_fpu and into callers
Touching TS_USEDFPU without touching CR0.TS is confusing, so don't do
it. By moving it into the callers, we always do the TS_USEDFPU next to
the CR0.TS accesses in the source code, and it's much easier to see how
the two go hand in hand.
Linus Torvalds [Thu, 16 Feb 2012 17:15:04 +0000 (09:15 -0800)]
i387: fix x86-64 preemption-unsafe user stack save/restore
Commit 5b1cbac37798 ("i387: make irq_fpu_usable() tests more robust")
added a sanity check to the #NM handler to verify that we never cause
the "Device Not Available" exception in kernel mode.
However, that check actually pinpointed a (fundamental) race where we do
cause that exception as part of the signal stack FPU state save/restore
code.
Because we use the floating point instructions themselves to save and
restore state directly from user mode, we cannot do that atomically with
testing the TS_USEDFPU bit: the user mode access itself may cause a page
fault, which causes a task switch, which saves and restores the FP/MMX
state from the kernel buffers.
This kind of "recursive" FP state save is fine per se, but it means that
when the signal stack save/restore gets restarted, it will now take the
'#NM' exception we originally tried to avoid. With preemption this can
happen even without the page fault - but because of the user access, we
cannot just disable preemption around the save/restore instruction.
There are various ways to solve this, including using the
"enable/disable_page_fault()" helpers to not allow page faults at all
during the sequence, and fall back to copying things by hand without the
use of the native FP state save/restore instructions.
However, the simplest thing to do is to just allow the #NM from kernel
space, but fix the race in setting and clearing CR0.TS that this all
exposed: the TS bit changes and the TS_USEDFPU bit absolutely have to be
atomic wrt scheduling, so while the actual state save/restore can be
interrupted and restarted, the act of actually clearing/setting CR0.TS
and the TS_USEDFPU bit together must not.
Instead of just adding random "preempt_disable/enable()" calls to what
is already excessively ugly code, this introduces some helper functions
that mostly mirror the "kernel_fpu_begin/end()" functionality, just for
the user state instead.
Those helper functions should probably eventually replace the other
ad-hoc CR0.TS and TS_USEDFPU tests too, but I'll need to think about it
some more: the task switching functionality in particular needs to
expose the difference between the 'prev' and 'next' threads, while the
new helper functions intentionally were written to only work with
'current'.
Anton Blanchard [Wed, 15 Feb 2012 18:48:22 +0000 (18:48 +0000)]
powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
perf on POWER stopped working after commit e050e3f0a71b (perf: Fix
broken interrupt rate throttling). That patch exposed a bug in
the POWER perf_events code.
Since the PMCs count upwards and take an exception when the top bit
is set, we want to write 0x80000000 - left in power_pmu_start. We were
instead programming in left which effectively disables the counter
until we eventually hit 0x80000000. This could take seconds or longer.
With the patch applied I get the expected number of samples:
SAMPLE events: 9948
Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: <stable@kernel.org>
powerpc: Disable interrupts early in Program Check
Program Check exceptions are the result of WARNs, BUGs, some
type of breakpoints, kprobe, and other illegal instructions.
We want interrupts (and thus preemption) to remain disabled
while doing the initial stage of testing the reason and
branching off to a debugger or kprobe, so we are still on
the original CPU which makes debugging easier in various cases.
This is how the code was intended, hence the local_irq_enable()
right in the middle of program_check_exception().
However, the assembly exception prologue for that exception was
incorrectly marked as enabling interrupts, which defeats that
(and records a redundant enable with lockdep).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Upstream changes to the way PHB resources are registered
broke the resource fixup for FSL boards.
We can no longer rely on the resource pointer array for the PHB's
pci_bus structure, so let's leave it alone and go straight for
the PHB resources instead. This also makes the code generally
more readable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ira Snyder [Fri, 6 Jan 2012 12:34:07 +0000 (12:34 +0000)]
powerpc: Fix kernel log of oops/panic instruction dump
A kernel oops/panic prints an instruction dump showing several
instructions before and after the instruction which caused the
oops/panic.
The code intended that the faulting instruction be enclosed in angle
brackets, however a bug caused the faulting instruction to be
interpreted by printk() as the message log level.
To fix this, the KERN_CONT log level is added before the actual text of
the printed message.
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Alexey Dobriyan [Sat, 14 Jan 2012 18:44:49 +0000 (21:44 +0300)]
crypto: sha512 - use standard ror64()
Use standard ror64() instead of hand-written.
There is no standard ror64, so create it.
The difference is shift value being "unsigned int" instead of uint64_t
(for which there is no reason). gcc starts to emit native ROR instructions
which it doesn't do for some reason currently. This should make the code
faster.
Patch survives in-tree crypto test and ping flood with hmac(sha512) on.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Thomas Graf [Wed, 15 Feb 2012 04:09:46 +0000 (04:09 +0000)]
veth: Enforce minimum size of VETH_INFO_PEER
VETH_INFO_PEER carries struct ifinfomsg plus optional IFLA
attributes. A minimal size of sizeof(struct ifinfomsg) must be
enforced or we may risk accessing that struct beyond the limits
of the netlink message.
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
This patch moves the MAC HW initialization and
the HW feature verification from the open to the probe
function as D. Miller suggested.
So the patch actually reorganizes and tidies-up some parts of
the driver and indeed fixes some problem when tune its HW features.
These can be overwritten by looking at the HW cap register at
run-time and that generated problems.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Reviewed-by: Francesco Virlinzi <francesco.virlinzi@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
stmmac: request_irq when use an ext wake irq line (v2)
In case of we use an external Wake-Up IRQ line
(priv->wol_irq != dev->irq) we need to invoke the
request_irq.
Signed-off-by: Francesco Virlinzi <francesco.virlinzi@st.com> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Tim Gardner [Wed, 15 Feb 2012 07:50:15 +0000 (07:50 +0000)]
ipheth: Add iPhone 4S
BugLink: http://bugs.launchpad.net/bugs/900802 Cc: stable@vger.kernel.org 3.2+ Signed-off-by: Till Kamppeter <till.kamppeter@gmail.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
mlx4: add unicast steering entries to resource_tracker
Add unicast steering entries to resource tracker.
Do qp_detach also for these entries when VF doesn't shut down gracefully.
Otherwise there is leakage of these resources, since they are not tracked.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il> Reviewed-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il> Signed-off-by: David S. Miller <davem@davemloft.net>
When adding new unicast steer entry, before moving qp to state ready,
actually before calling mlx4_RST2INIT_QP_wrapper(), there were added
a lot of entries with local_qpn=0 into radix tree.
This fact impacted the get_res() function and proper functioning
of resource tracker in addition to adding trash entries into radix tree.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il> Reviewed-by: Yevgeny Petrilin <yevgenyp@melllanox.co.il> Signed-off-by: David S. Miller <davem@davemloft.net>
When passing MLX4_UC_STEER=1 it was translated to value 2
after mlx4_QP_ATTACH_wrapper. Therefore in new_steering_entry()
unicast steer entries were added to index 2 of array of size 2.
Fixing this bug by shift right to one position.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il> Reviewed-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il> Signed-off-by: David S. Miller <davem@davemloft.net>
regmap: Fix cache defaults initialization from raw cache defaults
Currently registers with a value of 0 are ignored when initializing the register
defaults from raw defaults. This worked in the past, because registers without a
explicit default were assumed to have a default value of 0. This was changed in
commit b03622a8 ("regmap: Ensure rbtree syncs registers set to zero properly").
As a result registers, which have a raw default value of 0 are now assumed to
have no default. This again can result in unnecessary writes when syncing the
cache. It will also result in unnecessary reads for e.g. the first update
operation. In the case where readback is not possible this will even let the
update operation fail, if the register has not been written to before.
So this patch removes the check. Instead it adds a check to ignore raw defaults
for registers which are volatile, since those registers are not cached.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: stable@vger.kernel.org
Linus Torvalds [Wed, 15 Feb 2012 16:05:18 +0000 (08:05 -0800)]
i387: fix sense of sanity check
The check for save_init_fpu() (introduced in commit 5b1cbac37798: "i387:
make irq_fpu_usable() tests more robust") was the wrong way around, but
I hadn't noticed, because my "tests" were bogus: the FPU exceptions are
disabled by default, so even doing a divide by zero never actually
triggers this code at all unless you do extra work to enable them.
So if anybody did enable them, they'd get one spurious warning.
Linus Torvalds [Tue, 14 Feb 2012 23:26:42 +0000 (15:26 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
One small bug fix from Axel plus a fix for a build failure in unrealistic
but commonly built configs which for some reason manage to survive for
an awfully long time in -next without any reports.
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: Fix getting voltage in max8649_enable_time()
regulator: Fix mc13xxx regulator modular build (again)
Linus Torvalds [Tue, 14 Feb 2012 23:21:25 +0000 (15:21 -0800)]
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Quoth BenH:
"Here are a few powerpc fixes for 3.3, all pretty trivial. I also
added the patch to define GET_IP/SET_IP so we can use some more
asm-generic goodness."
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/pseries/eeh: Fix crash when error happens during device probe
powerpc/pseries: Fix partition migration hang in stop_topology_update
powerpc/powernv: Disable interrupts while taking phb->lock
powerpc: Fix WARN_ON in decrementer_check_overflow
powerpc/wsp: Fix IRQ affinity setting
powerpc: Implement GET_IP/SET_IP
powerpc/wsp: Permanently enable PCI class code workaround
Linus Torvalds [Tue, 14 Feb 2012 23:20:50 +0000 (15:20 -0800)]
Merge tag 'mmc-fixes-for-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
MMC fixes for 3.3-rc4:
* The most visible fix here is against a regression introduced in 3.3-rc1
that ran cards in Ultra High Speed mode even when they failed to initialize
in that mode, leading to lower-speed cards failing to mount.
* A lockdep warning introduced in 3.3-rc1 is fixed.
* Various other small driver fixes, most notably for a NULL dereference
when using highmem with dw_mmc.
* tag 'mmc-fixes-for-3.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc:
mmc: dw_mmc: Fix PIO mode with support of highmem
mmc: atmel-mci: save and restore sdioirq when soft reset is performed
mmc: block: Init ro_lock sysfs attr to fix lockdep warnings
mmc: sh_mmcif: fix late delayed work initialisation
mmc: tmio_mmc: fix card eject during IO with DMA
mmc: core: Fix comparison issue in mmc_compare_ext_csds
mmc: core: Fix PowerOff Notify suspend/resume
mmc: sdhci-pci: set Medfield SDIO as non-removable
mmc: core: add the capability for broken voltage
mmc: core: Fix low speed mmc card detection failure
mmc: esdhc: set the timeout to the max value
mmc: esdhc: add PIO mode support
mmc: core: Ensure clocks are always enabled before host interaction
mmc: of_mmc_spi: fix little endian support
mmc: core: UHS sdio card that fails should not exceed 50MHz
mmc: esdhc: fix errors when booting kernel on Freescale eSDHC version 2.3
Linus Torvalds [Tue, 14 Feb 2012 23:20:11 +0000 (15:20 -0800)]
Merge tag 'stable/for-linus-fixes-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Two fixes for VCPU offlining; One to fix the string format exposed
by the xen-pci[front|back] to conform to the one used in majority of
PCI drivers; Two fixes to make the code more resilient to invalid
configurations.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* tag 'stable/for-linus-fixes-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xenbus_dev: add missing error check to watch handling
xen/pci[front|back]: Use %d instead of %1x for displaying PCI devfn.
xen pvhvm: do not remap pirqs onto evtchns if !xen_have_vector_callback
xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic.
xen/bootup: During bootup suppress XENBUS: Unable to read cpu state
Eric Dumazet [Tue, 14 Feb 2012 10:27:09 +0000 (10:27 +0000)]
3c59x: shorten timer period for slave devices
Jean Delvare reported bonding on top of 3c59x adapters was not detecting
network cable removal fast enough.
3c59x indeed uses a 60 seconds timer to check link status if carrier is
on, and 5 seconds if carrier is off.
This patch reduces timer period to 5 seconds if device is a bonding
slave.
Reported-by: Jean Delvare <jdelvare@suse.de> Acked-by: Jean Delvare <jdelvare@suse.de> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Tue, 14 Feb 2012 10:11:59 +0000 (10:11 +0000)]
netpoll: netpoll_poll_dev() should access dev->flags
commit 5a698af53f (bond: service netpoll arp queue on master device)
tested IFF_SLAVE flag against dev->priv_flags instead of dev->flags
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: WANG Cong <amwang@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Neal Cardwell [Mon, 13 Feb 2012 20:22:08 +0000 (20:22 +0000)]
tcp: fix tcp_shifted_skb() adjustment of lost_cnt_hint for FACK
This commit ensures that lost_cnt_hint is correctly updated in
tcp_shifted_skb() for FACK TCP senders. The lost_cnt_hint adjustment
in tcp_sacktag_one() only applies to non-FACK senders, so FACK senders
need their own adjustment.
This applies the spirit of 1e5289e121372a3494402b1b131b41bfe1cf9b7f -
except now that the sequence range passed into tcp_sacktag_one() is
correct we need only have a special case adjustment for FACK.
Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Tue, 14 Feb 2012 17:09:24 +0000 (09:09 -0800)]
Merge tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
sound fixes for 3.3-rc4
Basically all small fixes suited as rc4: a few HD-audio regression fixes,
a stable fix for an old Dell laptop with intel8x0, and a simple fix for
ASoC fsi.
* tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: intel8x0: Fix default inaudible sound on Gateway M520
ALSA: hda - Fix silent speaker output on Acer Aspire 6935
ALSA: hda - Fix initialization of secondary capture source on VT1705
ASoC: fsi: fixup fsi_pointer() calculation method
ALSA: hda - Fix mute-LED VREF value for new HP laptops
Dave Airlie [Mon, 13 Feb 2012 12:18:37 +0000 (12:18 +0000)]
drm/radeon/kms: drop lock in return path of radeon_fence_count_emitted.
Silly bad return path.
Reported-and-Tested-by: Mikko Vinni Reviewed-by: Alex Deucher <alexander.deucher@amd.com> CC: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Daniel T Chen [Tue, 14 Feb 2012 04:44:22 +0000 (23:44 -0500)]
ALSA: intel8x0: Fix default inaudible sound on Gateway M520
BugLink: https://bugs.launchpad.net/bugs/930842
The reporter states that audio is inaudible by default without muting
'External Amplifier'. Add a quirk to handle his SSID so that changing
the control is not necessary.
Reported-and-tested-by: Benjamin Carlson <elderbubba0810@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Daniel T Chen <crimsun@ubuntu.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Linus Torvalds [Tue, 14 Feb 2012 04:34:44 +0000 (20:34 -0800)]
Merge git://git.samba.org/sfrench/cifs-2.6
* git://git.samba.org/sfrench/cifs-2.6:
cifs: don't return error from standard_receive3 after marking response malformed
cifs: request oplock when doing open on lookup
cifs: fix error handling when cifscreds key payload is an error
This updates the sha512 fix so that it doesn't cause excessive stack
usage on i386. This is done by reverting to the original code, and
avoiding the W duplication by moving its initialisation into the loop.
As the underlying code is in fact the one that we have used for years,
I'm pushing this now instead of postponing to the next cycle.
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: sha512 - Avoid stack bloat on i386
crypto: sha512 - Use binary and instead of modulus
powerpc/pseries/eeh: Fix crash when error happens during device probe
EEH may happen during a PCI driver probe. If the driver is trying to
access some register in a loop, the EEH code will try to print the
driver name. But the driver pointer in struct pci_dev is not set until
probe returns successfully.
Use a function to test if the device and the driver pointer is NULL
before accessing the driver's name.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Brian King [Wed, 11 Jan 2012 06:56:04 +0000 (06:56 +0000)]
powerpc/pseries: Fix partition migration hang in stop_topology_update
This fixes a hang that was observed during live partition migration.
Since stop_topology_update must not be called from an interrupt
context, call it earlier in the migration process. The hang observed
can be seen below:
powerpc: Fix WARN_ON in decrementer_check_overflow
We use __get_cpu_var() which triggers a false positive warning
in smp_processor_id() thinking interrupts are enabled (at this
point, they are soft-enabled but hard-disabled).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We call the cache_hwirq_map() function with a linux IRQ number
but it expects a HW irq number. This triggers a BUG on multic-chip
setups in addition to not doing the right thing.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc/wsp: Permanently enable PCI class code workaround
It appears that on the Chroma card, the class code of the root
complex is still wrong even on DD2 or later chips. This could
be a firmware issue, but that breaks resource allocation so let's
unconditionally fix it up.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
projects / mirror_ubuntu-jammy-kernel.git / log