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2015-08-04irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instanceJon Hunter
Commit 3228950621d9 ("irqchip: gic: Preserve gic V2 bypass bits in cpu ctrl register") added a new function, gic_cpu_if_up(), to program the GIC CPU_CTRL register. This function assumes that there is only one GIC instance present and hence always uses the chip data for the primary GIC controller. Although it is not common for there to be a secondary, some devices do support a secondary. Therefore, fix this by passing gic_cpu_if_up() a pointer to the appropriate chip data structure. Similarly, the function gic_cpu_if_down() only assumes that there is a single GIC instance present. Update this function so that an instance number is passed for the appropriate GIC and return an error code on failure. The vexpress TC2 (which has a single GIC) is currently the only user of this function and so update it accordingly. Note that because the TC2 only has a single GIC, the call to gic_cpu_if_down() should always be successful. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: <linux-arm-kernel@lists.infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1438332252-25248-2-git-send-email-jonathanh@nvidia.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-04crypto: doc - AEAD API conversionStephan Mueller
The AEAD API changes are now reflected in the crypto API doc book. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-04drm/atomic-helper: Add an atomice best_encoder callbackDaniel Vetter
With legacy helpers all the routing was already set up when calling best_encoder and so could be inspected. But with atomic it's staged, hence we need a new atomic compliant callback for drivers which need to inspect the requested state and can't just decided the best encoder statically. This is needed to fix up i915 dp mst where we need to pick the right encoder depending upon the requested CRTC for the connector. v2: Don't forget to amend the kerneldoc Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Acked-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-08-04perf: Add cycles to branch_infoAndi Kleen
Intel Skylake supports reporting the time in cycles a branch in the LBR took, to give a rough indication of the basic block performance. Export the cycle information in the branch_info structure. This can be done by just reusing some currently zero padding. This is just the generic header change. The architecture still needs to fill it in. There's no attempt to convert to real time, as we really want cycles here. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-5-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-04perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safeAndy Lutomirski
Code on the kprobe blacklist doesn't want unexpected int3 exceptions. It probably doesn't want unexpected debug exceptions either. Be safe: disallow breakpoints in nokprobes code. On non-CONFIG_KPROBES kernels, there is no kprobe blacklist. In that case, disallow kernel breakpoints entirely. It will be particularly important to keep hw breakpoints out of the entry and NMI code once we move debug exceptions off the IST stack. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03mpls: Use definition for reserved label checksRobert Shearman
In multiple locations there are checks for whether the label in hand is a reserved label or not using the arbritray value of 16. Factor this out into a #define for better maintainability and for documentation. Signed-off-by: Robert Shearman <rshearma@brocade.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-03mei: bus: add and call callback on notify eventAlexander Usyskin
Enable drivers on mei client bus to subscribe to asynchronous event notifications. Introduce events_mask to the existing callback infrastructure so it is possible to handle both RX and event notification. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03mei: add async event notification ioctlsTomas Winkler
Add ioctl IOCTL_MEI_NOTIFY_SET for enabling and disabling async event notification. Add ioctl IOCTL_MEI_NOTIFY_GET for receiving and acking an event notification. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03mei: bus: enable running fixup routines before device registrationTomas Winkler
Split the device registration into allocation and device struct initialization, device setup, and the final device registration. This why it is possible to run fixups and quirks during the setup stage on an initialized device. Each fixup routine effects do_match flag. If the flag is set to false at the end the device won't be registered on the bus. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03mei: bus: add me client device list infrastructureTomas Winkler
Instead of holding the list of host clients (me_cl) we want to keep the list me client devices (mei_cl_device) This way we can create host to me client connection only when needed. Add list head to mei_cl_device and cl_bus_lock Add bus_added flag to the me client (mei_me_client) to track if the appropriate mei_cl_device was already created and is_added flag to mei_cl_device to track if it was already added to the device list across the bus rescans Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03mei: bus: add reference to bus device in struct mei_cl_clientTomas Winkler
Add reference to the bus device (mei_device) for easier access. To ensures that referencing cldev->bus is valid during cldev life time we increase the bus ref counter on a client device creation and drop it on the device release. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03Avoid usb reset crashes by making tty_io cdevs truly dynamicRichard Watts
Avoid usb reset crashes by making tty_io cdevs truly dynamic Signed-off-by: Richard Watts <rrw@kynesim.co.uk> Reported-by: Duncan Mackintosh <DMackintosh@cbnl.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03Revert "libata: Implement NCQ autosense"Tejun Heo
This reverts commit 42b966fbf35da9c87f08d98f9b8978edf9e717cf. As implemented, ACS-4 sense reporting for ATA devices bypasses error diagnosis and handling in libata degrading EH behavior significantly. Revert the related changes for now. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org #v4.1+
2015-08-03Revert "libata: Implement support for sense data reporting"Tejun Heo
This reverts commit fe7173c206de63fc28475ee6ae42ff95c05692de. As implemented, ACS-4 sense reporting for ATA devices bypasses error diagnosis and handling in libata degrading EH behavior significantly. Revert the related changes for now. ATA_ID_COMMAND_SET_3/4 constants are not reverted as they're used by later changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org #v4.1+
2015-08-03Revert "libata-eh: Set 'information' field for autosense"Tejun Heo
This reverts commit a1524f226a02aa6edebd90ae0752e97cfd78b159. As implemented, ACS-4 sense reporting for ATA devices bypasses error diagnosis and handling in libata degrading EH behavior significantly. Revert the related changes for now. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org #v4.1+
2015-08-03thermal: consistently use int for temperaturesSascha Hauer
The thermal code uses int, long and unsigned long for temperatures in different places. Using an unsigned type limits the thermal framework to positive temperatures without need. Also several drivers currently will report temperatures near UINT_MAX for temperatures below 0°C. This will probably immediately shut the machine down due to overtemperature if started below 0°C. 'long' is 64bit on several architectures. This is not needed since INT_MAX °mC is above the melting point of all known materials. Consistently use a plain 'int' for temperatures throughout the thermal code and the drivers. This only changes the places in the drivers where the temperature is passed around as pointer, when drivers internally use another type this is not changed. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com> Reviewed-by: Darren Hart <dvhart@linux.intel.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Peter Feuerer <peter@piie.net> Cc: Punit Agrawal <punit.agrawal@arm.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Jean Delvare <jdelvare@suse.de> Cc: Peter Feuerer <peter@piie.net> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Lukasz Majewski <l.majewski@samsung.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: linux-acpi@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-omap@vger.kernel.org Cc: linux-samsung-soc@vger.kernel.org Cc: Guenter Roeck <linux@roeck-us.net> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Darren Hart <dvhart@infradead.org> Cc: lm-sensors@lm-sensors.org Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2015-08-03arm64: psci: factor invocation code to driversMark Rutland
To enable sharing with arm, move the core PSCI framework code to drivers/firmware. This results in a minor gain in lines of code, but this will quickly be amortised by the removal of code currently duplicated in arch/arm. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-08-03ARM: STi: DT: Move reset controller constants into common locationPhilipp Zabel
By popular vote, the DT binding includes for reset controllers are located in include/dt-bindings/reset/. Move the STi reset constants in there, too, to avoid confusion. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Patrice Chotard <patrice.chotard@st.com>
2015-08-03sched/fair: Rewrite runnable load and utilization average trackingYuyang Du
The idea of runnable load average (let runnable time contribute to weight) was proposed by Paul Turner and Ben Segall, and it is still followed by this rewrite. This rewrite aims to solve the following issues: 1. cfs_rq's load average (namely runnable_load_avg and blocked_load_avg) is updated at the granularity of an entity at a time, which results in the cfs_rq's load average is stale or partially updated: at any time, only one entity is up to date, all other entities are effectively lagging behind. This is undesirable. To illustrate, if we have n runnable entities in the cfs_rq, as time elapses, they certainly become outdated: t0: cfs_rq { e1_old, e2_old, ..., en_old } and when we update: t1: update e1, then we have cfs_rq { e1_new, e2_old, ..., en_old } t2: update e2, then we have cfs_rq { e1_old, e2_new, ..., en_old } ... We solve this by combining all runnable entities' load averages together in cfs_rq's avg, and update the cfs_rq's avg as a whole. This is based on the fact that if we regard the update as a function, then: w * update(e) = update(w * e) and update(e1) + update(e2) = update(e1 + e2), then w1 * update(e1) + w2 * update(e2) = update(w1 * e1 + w2 * e2) therefore, by this rewrite, we have an entirely updated cfs_rq at the time we update it: t1: update cfs_rq { e1_new, e2_new, ..., en_new } t2: update cfs_rq { e1_new, e2_new, ..., en_new } ... 2. cfs_rq's load average is different between top rq->cfs_rq and other task_group's per CPU cfs_rqs in whether or not blocked_load_average contributes to the load. The basic idea behind runnable load average (the same for utilization) is that the blocked state is taken into account as opposed to only accounting for the currently runnable state. Therefore, the average should include both the runnable/running and blocked load averages. This rewrite does that. In addition, we also combine runnable/running and blocked averages of all entities into the cfs_rq's average, and update it together at once. This is based on the fact that: update(runnable) + update(blocked) = update(runnable + blocked) This significantly reduces the code as we don't need to separately maintain/update runnable/running load and blocked load. 3. How task_group entities' share is calculated is complex and imprecise. We reduce the complexity in this rewrite to allow a very simple rule: the task_group's load_avg is aggregated from its per CPU cfs_rqs's load_avgs. Then group entity's weight is simply proportional to its own cfs_rq's load_avg / task_group's load_avg. To illustrate, if a task_group has { cfs_rq1, cfs_rq2, ..., cfs_rqn }, then, task_group_avg = cfs_rq1_avg + cfs_rq2_avg + ... + cfs_rqn_avg, then cfs_rqx's entity's share = cfs_rqx_avg / task_group_avg * task_group's share To sum up, this rewrite in principle is equivalent to the current one, but fixes the issues described above. Turns out, it significantly reduces the code complexity and hence increases clarity and efficiency. In addition, the new averages are more smooth/continuous (no spurious spikes and valleys) and updated more consistently and quickly to reflect the load dynamics. As a result, we have less load tracking overhead, better performance, and especially better power efficiency due to more balanced load. Signed-off-by: Yuyang Du <yuyang.du@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arjan@linux.intel.com Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: fengguang.wu@intel.com Cc: len.brown@intel.com Cc: morten.rasmussen@arm.com Cc: pjt@google.com Cc: rafael.j.wysocki@intel.com Cc: umgwanakikbuti@gmail.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1436918682-4971-3-git-send-email-yuyang.du@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03stop_machine: Use 'cpu_stop_fn_t' where possibleOleg Nesterov
Cosmetic, but 'cpu_stop_fn_t' actually makes the code more readable and it doesn't break cscope. And most of the declarations already use it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: der.herr@hofr.at Cc: paulmck@linux.vnet.ibm.com Cc: riel@redhat.com Cc: viro@ZenIV.linux.org.uk Link: http://lkml.kernel.org/r/20150630012955.GA23937@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03stop_machine: Unexport __stop_machine()Oleg Nesterov
The only caller outside of stop_machine.c is _cpu_down(), it can use stop_machine(). get_online_cpus() is fine under cpu_hotplug_begin(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: der.herr@hofr.at Cc: paulmck@linux.vnet.ibm.com Cc: riel@redhat.com Cc: viro@ZenIV.linux.org.uk Link: http://lkml.kernel.org/r/20150630012951.GA23934@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()Konstantin Khlebnikov
These functions check should_resched() before unlocking spinlock/bh-enable: preempt_count always non-zero => should_resched() always returns false. cond_resched_lock() worked iff spin_needbreak is set. This patch adds argument "preempt_offset" to should_resched(). preempt_count offset constants for that: PREEMPT_DISABLE_OFFSET - offset after preempt_disable() PREEMPT_LOCK_OFFSET - offset after spin_lock() SOFTIRQ_DISABLE_OFFSET - offset after local_bh_distable() SOFTIRQ_LOCK_OFFSET - offset after spin_lock_bh() Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Graf <agraf@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: bdb438065890 ("sched: Extract the basic add/sub preempt_count modifiers") Link: http://lkml.kernel.org/r/20150715095204.12246.98268.stgit@buzz Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03sched/fair: Beef up wake_wide()Mike Galbraith
Josef Bacik reported that Facebook sees better performance with their 1:N load (1 dispatch/node, N workers/node) when carrying an old patch to try very hard to wake to an idle CPU. While looking at wake_wide(), I noticed that it doesn't pay attention to the wakeup of a many partner waker, returning 1 only when waking one of its many partners. Correct that, letting explicit domain flags override the heuristic. While at it, adjust task_struct bits, we don't need a 64-bit counter. Tested-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> [ Tidy things up. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-team<Kernel-team@fb.com> Cc: morten.rasmussen@arm.com Cc: riel@redhat.com Link: http://lkml.kernel.org/r/1436888390.7983.49.camel@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03sched: Introduce the 'trace_sched_waking' tracepointPeter Zijlstra
Mathieu reported that since 317f394160e9 ("sched: Move the second half of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of context of the waker. This is a problem when you want to analyse wakeup paths because it is now very hard to correlate the wakeup event to whoever issued the wakeup. OTOH trace_sched_wakeup() is issued at the point where we set p->state = TASK_RUNNING, which is right were we hand the task off to the scheduler, so this is an important point when looking at scheduling behaviour, up to here its been the wakeup path everything hereafter is due to scheduler policy. To bridge this gap, introduce a second tracepoint: trace_sched_waking. It is guaranteed to be called in the waker context. Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Francis Giraldeau <francis.giraldeau@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150609091336.GQ3644@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03sched/cputime: Guarantee stime + utime == rtimePeter Zijlstra
While the current code guarantees monotonicity for stime and utime independently of one another, it does not guarantee that the sum of both is equal to the total time we started out with. This confuses things (and peoples) who look at this sum, like top, and will report >100% usage followed by a matching period of 0%. Rework the code to provide both individual monotonicity and a coherent sum. Suggested-by: Fredrik Markstrom <fredrik.markstrom@gmail.com> Reported-by: Fredrik Markstrom <fredrik.markstrom@gmail.com> Tested-by: Fredrik Markstrom <fredrik.markstrom@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jason.low2@hp.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03jump label, locking/static_keys: Update docsJason Baron
Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: bp@alien8.de Cc: davem@davemloft.net Cc: ddaney@caviumnetworks.com Cc: heiko.carstens@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: liuj97@gmail.com Cc: luto@amacapital.net Cc: michael@ellerman.id.au Cc: rabin@rab.in Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: vbabka@suse.cz Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/6b50f2f6423a2244f37f4b1d2d6c211b9dcdf4f8.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03locking/static_keys: Add a new static_key interfacePeter Zijlstra
There are various problems and short-comings with the current static_key interface: - static_key_{true,false}() read like a branch depending on the key value, instead of the actual likely/unlikely branch depending on init value. - static_key_{true,false}() are, as stated above, tied to the static_key init values STATIC_KEY_INIT_{TRUE,FALSE}. - we're limited to the 2 (out of 4) possible options that compile to a default NOP because that's what our arch_static_branch() assembly emits. So provide a new static_key interface: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); Which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. This means adding a second arch_static_branch_jump() assembly helper which emits a JMP per default. In order to determine the right instruction for the right state, encode the branch type in the LSB of jump_entry::key. This is the final step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") ... but it also allows new static key combinations that will give us performance enhancements in the subsequent patches. Tested-by: Rabin Vincent <rabin@rab.in> # arm Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> # ppc Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03locking/static_keys: Add static_key_{en,dis}able() helpersPeter Zijlstra
Add two helpers to make it easier to treat the refcount as boolean. Suggested-by: Jason Baron <jasonbaron0@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03jump_label, locking/static_keys: Rename JUMP_LABEL_TYPE_* and related ↵Peter Zijlstra
helpers to the static_key* pattern Rename the JUMP_LABEL_TYPE_* macros to be JUMP_TYPE_* and move the inline helpers into kernel/jump_label.c, since that's the only place they're ever used. Also rename the helpers where it's all about static keys. This is the second step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}Peter Zijlstra
Since we've already stepped away from ENABLE is a JMP and DISABLE is a NOP with the branch_default bits, and are going to make it even worse, rename it to make it all clearer. This way we don't mix multiple levels of logic attributes, but have a plain 'physical' name for what the current instruction patching status of a jump label is. This is a first step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org [ Beefed up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03Merge branch 'x86/asm' into locking/coreIngo Molnar
Upcoming changes to static keys is interacting/conflicting with the following pending TSC commits in tip:x86/asm: 4ea1636b04db x86/asm/tsc: Rename native_read_tsc() to rdtsc() ... So merge it into the locking tree to have a smoother resolution. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03locking, arch: use WRITE_ONCE()/READ_ONCE() in ↵Andrey Konovalov
smp_store_release()/smp_load_acquire() Replace ACCESS_ONCE() macro in smp_store_release() and smp_load_acquire() with WRITE_ONCE() and READ_ONCE() on x86, arm, arm64, ia64, metag, mips, powerpc, s390, sparc and asm-generic since ACCESS_ONCE() does not work reliably on non-scalar types. WRITE_ONCE() and READ_ONCE() were introduced in the following commits: 230fa253df63 ("kernel: Provide READ_ONCE and ASSIGN_ONCE") 43239cbe79fc ("kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Alexander Duyck <alexander.h.duyck@redhat.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@suse.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1438528264-714-1-git-send-email-andreyknvl@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03Merge branch 'locking/urgent', tag 'v4.2-rc5' into locking/core, to pick up ↵Ingo Molnar
fixes before applying new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-02target: Drop iSCSI use of mutex around max_cmd_sn incrementRoland Dreier
In a performance profile, taking a mutex in iscsit_increment_maxcmdsn() shows up very high. However taking a mutex around "sess->max_cmd_sn += 1" seems pretty silly: we're not serializing against other contexts in any useful way. I did a quick audit and there don't appear to be any other places that use max_cmd_sn within the mutex more than once, so this lock can't be providing any useful serialization. (Get correct values for logging - fix whitespace damage) Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Spencer Baugh <sbaugh@catern.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-08-02iscsi-target: Add tpg_enabled_sendtargets for disabled discoveryDavid Disseldorp
This patch adds a new tpg_enabled_sendtargets configfs attribute to allow in-band sendtargets discovery information to include target-portal-groups (TPGs) in !TPG_STATE_ACTIVE state. This functionality is useful for clustered iSCSI targets, where TPGTs handled on remote cluster nodes should be advertised in the SendTargets response. By default, this new attribute retains the default behaviour of existing code which to ignore portal-groups in !TPG_STATE_ACTIVE state. Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-08-02ebpf: add skb->hash to offset map for usage in {cls, act}_bpf or filtersDaniel Borkmann
Add skb->hash to the __sk_buff offset map, so it can be accessed from an eBPF program. We currently already do this for classic BPF filters, but not yet on eBPF, it might be useful as a demuxer in combination with helpers like bpf_clone_redirect(), toy example: __section("cls-lb") int ingress_main(struct __sk_buff *skb) { unsigned int which = 3 + (skb->hash & 7); /* bpf_skb_store_bytes(skb, ...); */ /* bpf_l{3,4}_csum_replace(skb, ...); */ bpf_clone_redirect(skb, which, 0); return -1; } I was thinking whether to add skb_get_hash(), but then concluded the raw skb->hash seems fine in this case: we can directly access the hash w/o extra eBPF helper function call, it's filled out by many NICs on ingress, and in case the entropy level would not be sufficient, people can still implement their own specific sw fallback hash mix anyway. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-02include: linux: iio: Add missing kernel doc fieldCristina Opriceana
Fix kernel doc for the iio_dev_attr structure by adding its missing field. Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-02include: linux: iio: Fix function parameter name in kernel docCristina Opriceana
Fix buffer name from kernel doc according to the function parameter. Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-07-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: arch/s390/net/bpf_jit_comp.c drivers/net/ethernet/ti/netcp_ethss.c net/bridge/br_multicast.c net/ipv4/ip_fragment.c All four conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Must teardown SR-IOV before unregistering netdev in igb driver, from Alex Williamson. 2) Fix ipv6 route unreachable crash in IPVS, from Alex Gartrell. 3) Default route selection in ipv4 should take the prefix length, table ID, and TOS into account, from Julian Anastasov. 4) sch_plug must have a reset method in order to purge all buffered packets when the qdisc is reset, likewise for sch_choke, from WANG Cong. 5) Fix deadlock and races in slave_changelink/br_setport in bridging. From Nikolay Aleksandrov. 6) mlx4 bug fixes (wrong index in port even propagation to VFs, overzealous BUG_ON assertion, etc.) from Ido Shamay, Jack Morgenstein, and Or Gerlitz. 7) Turn off klog message about SCTP userspace interface compat that makes no sense at all, from Daniel Borkmann. 8) Fix unbounded restarts of inet frag eviction process, causing NMI watchdog soft lockup messages, from Florian Westphal. 9) Suspend/resume fixes for r8152 from Hayes Wang. 10) Fix busy loop when MSG_WAITALL|MSG_PEEK is used in TCP recv, from Sabrina Dubroca. 11) Fix performance regression when removing a lot of routes from the ipv4 routing tables, from Alexander Duyck. 12) Fix device leak in AF_PACKET, from Lars Westerhoff. 13) AF_PACKET also has a header length comparison bug due to signedness, from Alexander Drozdov. 14) Fix bug in EBPF tail call generation on x86, from Daniel Borkmann. 15) Memory leaks, TSO stats, watchdog timeout and other fixes to thunderx driver from Sunil Goutham and Thanneeru Srinivasulu. 16) act_bpf can leak memory when replacing programs, from Daniel Borkmann. 17) WOL packet fixes in gianfar driver, from Claudiu Manoil. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (79 commits) stmmac: fix missing MODULE_LICENSE in stmmac_platform gianfar: Enable device wakeup when appropriate gianfar: Fix suspend/resume for wol magic packet gianfar: Fix warning when CONFIG_PM off act_pedit: check binding before calling tcf_hash_release() net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket net: sched: fix refcount imbalance in actions r8152: reset device when tx timeout r8152: add pre_reset and post_reset qlcnic: Fix corruption while copying act_bpf: fix memory leaks when replacing bpf programs net: thunderx: Fix for crash while BGX teardown net: thunderx: Add PCI driver shutdown routine net: thunderx: Fix crash when changing rss with mutliple traffic flows net: thunderx: Set watchdog timeout value net: thunderx: Wakeup TXQ only if CQE_TX are processed net: thunderx: Suppress alloc_pages() failure warnings net: thunderx: Fix TSO packet statistic net: thunderx: Fix memory leak when changing queue count net: thunderx: Fix RQ_DROP miscalculation ...
2015-07-31ipv6: Enable auto flow labels by defaultTom Herbert
Initialize auto_flowlabels to one. This enables automatic flow labels, individual socket may disable them using the IPV6_AUTOFLOWLABEL socket option. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31ipv6: Implement different admin modes for automatic flow labelsTom Herbert
Change the meaning of net.ipv6.auto_flowlabels to provide a mode for automatic flow labels generation. There are four modes: 0: flow labels are disabled 1: flow labels are enabled, sockets can opt-out 2: flow labels are allowed, sockets can opt-in 3: flow labels are enabled and enforced, no opt-out for sockets np->autoflowlabel is initialized according to the sysctl value. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabelTom Herbert
We can't call skb_get_hash here since the packet is not complete to do flow_dissector. Create hash based on flowi6 instead. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31net: Add functions to get skb->hash based on flow structuresTom Herbert
Add skb_get_hash_flowi6 and skb_get_hash_flowi4 which derive an sk_buff hash from flowi6 and flowi4 structures respectively. These functions can be called when creating a packet in the output path where the new sk_buff does not yet contain a fully formed packet that is parsable by flow dissector. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31Merge tag 'sound-4.2-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "This became a relative big update as it includes the collected ASoC fixes. There are a few fixes in ASoC core side, mostly for DAPM and the new topology API. The rest are various ASoC driver-specific fixes, as well as the usual HD-audio and USB-audio quirks" * tag 'sound-4.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (29 commits) ALSA: hda - Fix MacBook Pro 5,2 quirk ALSA: hda - Fix race between PM ops and HDA init/probe ALSA: usb-audio: add dB range mapping for some devices ALSA: hda - Apply a fixup to Dell Vostro 5480 ALSA: hda - Add pin quirk for the headset mic jack detection on Dell laptop ALSA: hda - Apply fixup for another Toshiba Satellite S50D ALSA: fireworks: add support for AudioFire2 quirk ALSA: hda - Fix the headset mic that will not work on Dell desktop machine ALSA: hda - fix cs4210_spdif_automute() ASoC: pcm1681: Fix setting de-emphasis sampling rate selection ASoC: ssm4567: Keep TDM_BCLKS in ssm4567_set_dai_fmt ASoC: sgtl5000: Fix up define for SGTL5000_SMALL_POP ASoC: dapm: Don't add prefix to widget stream name ASoC: rt5645: Check if codec is initialized in workqueue handler ASoC: Intel: Get correct usage_count value to load firmware ASoC: topology: Fix to add dapm mixer info ASoC: zx: spdif: Fix devm_ioremap_resource return value check ASoC: zx: i2s: Fix devm_ioremap_resource return value check ASoC: mediatek: Use platform_of_node for machine drivers ASoC: Free card DAPM context on snd_soc_instantiate_card() error path ...
2015-07-31bonding: add tlb_dynamic_lb netlink supportNikolay Aleksandrov
tlb_dynamic_lb could be set only via sysfs, this patch allows it to be set via netlink. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31vxlan: expose COLLECT_METADATA flag to user spaceAlexei Starovoitov
Two vxlan driver flags FLOWBASED and COLLECT_METADATA need to be set to make use of its new flow mode. The former already exposed. Expose the latter. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argumentRoopa Prabhu
This patch adds net argument to ipv6_stub_impl.ipv6_dst_lookup for use cases where sk is not available (like mpls). sk appears to be needed to get the namespace 'net' and is optional otherwise. This patch series changes ipv6_stub_impl.ipv6_dst_lookup to take net argument. sk remains optional. All callers of ipv6_stub_impl.ipv6_dst_lookup have been modified to pass net. I have modified them to use already available 'net' in the scope of the call. I can change them to sock_net(sk) to avoid any unintended change in behaviour if sock namespace is different. They dont seem to be from code inspection. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31bpf: add helpers to access tunnel metadataAlexei Starovoitov
Introduce helpers to let eBPF programs attached to TC manipulate tunnel metadata: bpf_skb_[gs]et_tunnel_key(skb, key, size, flags) skb: pointer to skb key: pointer to 'struct bpf_tunnel_key' size: size of 'struct bpf_tunnel_key' flags: room for future extensions First eBPF program that uses these helpers will allocate per_cpu metadata_dst structures that will be used on TX. On RX metadata_dst is allocated by tunnel driver. Typical usage for TX: struct bpf_tunnel_key tkey; ... populate tkey ... bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0); bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); RX: struct bpf_tunnel_key tkey = {}; bpf_skb_get_tunnel_key(skb, &tkey, sizeof(tkey), 0); ... lookup or redirect based on tkey ... 'struct bpf_tunnel_key' will be extended in the future by adding elements to the end and the 'size' argument will indicate which fields are populated, thereby keeping backwards compatibility. The 'flags' argument may be used as well when the 'size' is not enough or to indicate completely different layout of bpf_tunnel_key. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31PM / Domains: Remove intermediate states from the power off sequenceUlf Hansson
Genpd's ->runtime_suspend() (assigned to pm_genpd_runtime_suspend()) doesn't immediately walk the hierarchy of ->runtime_suspend() callbacks. Instead, pm_genpd_runtime_suspend() calls pm_genpd_poweroff() which postpones that until *all* the devices in the genpd are runtime suspended. When pm_genpd_poweroff() discovers that the last device in the genpd is about to be runtime suspended, it calls __pm_genpd_save_device() for *all* the devices in the genpd sequentially. Furthermore, __pm_genpd_save_device() invokes the ->start() callback, walks the hierarchy of the ->runtime_suspend() callbacks and invokes the ->stop() callback. This causes a "thundering herd" problem. Let's address this issue by having pm_genpd_runtime_suspend() immediately walk the hierarchy of the ->runtime_suspend() callbacks, instead of postponing that to the power off sequence via pm_genpd_poweroff(). If the selected ->runtime_suspend() callback doesn't return an error code, call pm_genpd_poweroff() to see if it's feasible to also power off the PM domain. Adopting this change enables us to simplify parts of the code in genpd, for example the locking mechanism. Additionally, it gives some positive side effects, as described below. i) One device's ->runtime_resume() latency is no longer affected by other devices' latencies in a genpd. The complexity genpd has to support the option to abort the power off sequence suffers from latency issues. More precisely, a device that is requested to be runtime resumed, may end up waiting for __pm_genpd_save_device() to complete its operations for *another* device. That's because pm_genpd_poweroff() can't confirm an abort request while it waits for __pm_genpd_save_device() to return. As this patch removes the intermediate states in pm_genpd_poweroff() while powering off the PM domain, we no longer need the ability to abort that sequence. ii) Make pm_runtime[_status]_suspended() reliable when used with genpd. Until the last device in a genpd becomes idle, pm_genpd_runtime_suspend() will return 0 without actually walking the hierarchy of the ->runtime_suspend() callbacks. However, by returning 0 the runtime PM core considers the device as runtime_suspended, so pm_runtime[_status]_suspended() will return true, even though the device isn't (yet) runtime suspended. After this patch, since pm_genpd_runtime_suspend() immediately walks the hierarchy of the ->runtime_suspend() callbacks, pm_runtime[_status]_suspended() will accurately reflect the status of the device. iii) Enable fine-grained PM through runtime PM callbacks in drivers/subsystems. There are currently cases were drivers/subsystems implements runtime PM callbacks to deploy fine-grained PM (e.g. gate clocks, move pinctrl to power-save state, etc.). While using the genpd, pm_genpd_runtime_suspend() postpones invoking these callbacks until *all* the devices in the genpd are runtime suspended. In essence, one runtime resumed device prevents fine-grained PM for other devices within the same genpd. After this patch, since pm_genpd_runtime_suspend() immediately walks the hierarchy of the ->runtime_suspend() callbacks, fine-grained PM is enabled throughout all the levels of runtime PM callbacks. iiii) Enable fine-grained PM for IRQ safe devices Per the definition for an IRQ safe device, its runtime PM callbacks must be able to execute in atomic context. In the path while genpd walks the hierarchy of the ->runtime_suspend() callbacks for the device, it uses a mutex. Therefore, genpd prevents that path to be executed for IRQ safe devices. As this patch changes pm_genpd_runtime_suspend() to immediately walk the hierarchy of the ->runtime_suspend() callbacks and without needing to use a mutex, fine-grained PM is enabled throughout all the levels of runtime PM callbacks for IRQ safe devices. Unfortunately this patch also comes with a drawback, as described in the summary below. Driver's/subsystem's runtime PM callbacks may be invoked even when the genpd hasn't actually powered off the PM domain, potentially introducing unnecessary latency. However, in most cases, saving/restoring register contexts for devices are typically fast operations or can be optimized in device specific ways (e.g. shadow copies of register contents in memory, device-specific checks to see if context has been lost before restoring context, etc.). Still, in some cases the driver/subsystem may suffer from latency if runtime PM is used in a very fine-grained manner (e.g. for each IO request or xfer). To prevent that extra overhead, the driver/subsystem may deploy the runtime PM autosuspend feature. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>