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* genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amdRafael J. Wysocki2024-03-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a problem when a driver requests a shared interrupt line to run a threaded handler on it without IRQF_ONESHOT set if that flag has been set already for the IRQ in question by somebody else. Namely, the request fails which usually leads to a probe failure even though the driver might have worked just fine with IRQF_ONESHOT, but it does not want to use it by default. Currently, the only way to handle this is to try to request the IRQ without IRQF_ONESHOT, but with IRQF_PROBE_SHARED set and if this fails, try again with IRQF_ONESHOT set. However, this is a bit cumbersome and not very clean. When commit 7a36b901a6eb ("ACPI: OSL: Use a threaded interrupt handler for SCI") switched the ACPI subsystem over to using a threaded interrupt handler for the SCI, it had to use IRQF_ONESHOT for it because that's required due to the way the SCI handler works (it needs to walk all of the enabled GPEs before the interrupt line can be unmasked). The SCI interrupt line is not shared with other users very often due to the SCI handling overhead, but on sone systems it is shared and when the other user of it attempts to install a threaded handler, a flags mismatch related to IRQF_ONESHOT may occur. As it turned out, that happened to the pinctrl-amd driver and so commit 4451e8e8415e ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request") attempted to address the issue by adding IRQF_ONESHOT to the interrupt flags in that driver, but this is now causing an IRQF_ONESHOT-related mismatch to occur on another system which cannot boot as a result of it. Clearly, pinctrl-amd can work with IRQF_ONESHOT if need be, but it should not set that flag by default, so it needs a way to indicate that to the interrupt subsystem. To that end, introdcuce a new interrupt flag, IRQF_COND_ONESHOT, which will only have effect when the IRQ line is shared and IRQF_ONESHOT has been set for it already, in which case it will be promoted to the latter. This is sufficient for drivers sharing the interrupt line with the SCI as it is requested by the ACPI subsystem before any drivers are probed, so they will always see IRQF_ONESHOT set for the interrupt in question. Fixes: 4451e8e8415e ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request") Reported-by: Francisco Ayala Le Brun <francisco@videowindow.eu> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Cc: 6.8+ <stable@vger.kernel.org> # 6.8+ Closes: https://lore.kernel.org/lkml/CAN-StX1HqWqi+YW=t+V52-38Mfp5fAz7YHx4aH-CQjgyNiKx3g@mail.gmail.com/ Link: https://lore.kernel.org/r/12417336.O9o76ZdvQC@kreacher
* Merge tag 'rcu-next-v6.7' of ↵Linus Torvalds2023-10-301-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks Pull RCU updates from Frederic Weisbecker: - RCU torture, locktorture and generic torture infrastructure updates that include various fixes, cleanups and consolidations. Among the user visible things, ftrace dumps can now be found into their own file, and module parameters get better documented and reported on dumps. - Generic and misc fixes all over the place. Some highlights: * Hotplug handling has seen some light cleanups and comments * An RCU barrier can now be triggered through sysfs to serialize memory stress testing and avoid OOM * Object information is now dumped in case of invalid callback invocation * Also various SRCU issues, too hard to trigger to deserve urgent pull requests, have been fixed - RCU documentation updates - RCU reference scalability test minor fixes and doc improvements. - RCU tasks minor fixes - Stall detection updates. Introduce RCU CPU Stall notifiers that allows a subsystem to provide informations to help debugging. Also cure some false positive stalls. * tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (56 commits) srcu: Only accelerate on enqueue time locktorture: Check the correct variable for allocation failure srcu: Fix callbacks acceleration mishandling rcu: Comment why callbacks migration can't wait for CPUHP_RCUTREE_PREP rcu: Standardize explicit CPU-hotplug calls rcu: Conditionally build CPU-hotplug teardown callbacks rcu: Remove references to rcu_migrate_callbacks() from diagrams rcu: Assume rcu_report_dead() is always called locally rcu: Assume IRQS disabled from rcu_report_dead() rcu: Use rcu_segcblist_segempty() instead of open coding it rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects srcu: Fix srcu_struct node grpmask overflow on 64-bit systems torture: Convert parse-console.sh to mktemp rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle() rcutorture: Replace schedule_timeout*() 1-jiffy waits with HZ/20 torture: Add kvm.sh --debug-info argument locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers doc: Catch-up update for locktorture module parameters locktorture: Add call_rcu_chains module parameter locktorture: Add new module parameters to lock_torture_print_module_parms() ...
| * rcu: Standardize explicit CPU-hotplug callsFrederic Weisbecker2023-10-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rcu_report_dead() and rcutree_migrate_callbacks() have their headers in rcupdate.h while those are pure rcutree calls, like the other CPU-hotplug functions. Also rcu_cpu_starting() and rcu_report_dead() have different naming conventions while they mirror each other's effects. Fix the headers and propose a naming that relates both functions and aligns with the prefix of other rcutree CPU-hotplug functions. Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
* | timers: Tag (hr)timer softirq as hotplug safeFrederic Weisbecker2023-09-271-1/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Specific stress involving frequent CPU-hotplug operations, such as running rcutorture for example, may trigger the following message: NOHZ tick-stop error: local softirq work is pending, handler #02!!!" This happens in the CPU-down hotplug process, after CPUHP_AP_SMPBOOT_THREADS whose teardown callback parks ksoftirqd, and before the target CPU shuts down through CPUHP_AP_IDLE_DEAD. In this fragile intermediate state, softirqs waiting for threaded handling may be forever ignored and eventually reported by the idle task as in the above example. However some vectors are known to be safe as long as the corresponding subsystems have teardown callbacks handling the migration of their events. The above error message reports pending timers softirq although this vector can be considered as hotplug safe because the CPUHP_TIMERS_PREPARE teardown callback performs the necessary migration of timers after the death of the CPU. Hrtimers also have a similar hotplug handling. Therefore this error message, as far as (hr-)timers are concerned, can be considered spurious and the relevant softirq vectors can be marked as hotplug safe. Fixes: 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230912104406.312185-6-frederic@kernel.org
* Merge tag 'sched-core-2022-05-23' of ↵Linus Torvalds2022-05-241-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Updates to scheduler metrics: - PELT fixes & enhancements - PSI fixes & enhancements - Refactor cpu_util_without() - Updates to instrumentation/debugging: - Remove sched_trace_*() helper functions - can be done via debug info - Fix double update_rq_clock() warnings - Introduce & use "preemption model accessors" to simplify some of the Kconfig complexity. - Make softirq handling RT-safe. - Misc smaller fixes & cleanups. * tag 'sched-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: topology: Remove unused cpu_cluster_mask() sched: Reverse sched_class layout sched/deadline: Remove superfluous rq clock update in push_dl_task() sched/core: Avoid obvious double update_rq_clock warning smp: Make softirq handling RT safe in flush_smp_call_function_queue() smp: Rename flush_smp_call_function_from_idle() sched: Fix missing prototype warnings sched/fair: Remove cfs_rq_tg_path() sched/fair: Remove sched_trace_*() helper functions sched/fair: Refactor cpu_util_without() sched/fair: Revise comment about lb decision matrix sched/psi: report zeroes for CPU full at the system level sched/fair: Delete useless condition in tg_unthrottle_up() sched/fair: Fix cfs_rq_clock_pelt() for throttled cfs_rq sched/fair: Move calculate of avg_load to a better location mailmap: Update my email address to @redhat.com MAINTAINERS: Add myself as scheduler topology reviewer psi: Fix trigger being fired unexpectedly at initial ftrace: Use preemption model accessors for trace header printout kcsan: Use preemption model accessors
| * smp: Make softirq handling RT safe in flush_smp_call_function_queue()Sebastian Andrzej Siewior2022-05-011-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | flush_smp_call_function_queue() invokes do_softirq() which is not available on PREEMPT_RT. flush_smp_call_function_queue() is invoked from the idle task and the migration task with preemption or interrupts disabled. So RT kernels cannot process soft interrupts in that context as that has to acquire 'sleeping spinlocks' which is not possible with preemption or interrupts disabled and forbidden from the idle task anyway. The currently known SMP function call which raises a soft interrupt is in the block layer, but this functionality is not enabled on RT kernels due to latency and performance reasons. RT could wake up ksoftirqd unconditionally, but this wants to be avoided if there were soft interrupts pending already when this is invoked in the context of the migration task. The migration task might have preempted a threaded interrupt handler which raised a soft interrupt, but did not reach the local_bh_enable() to process it. The "running" ksoftirqd might prevent the handling in the interrupt thread context which is causing latency issues. Add a new function which handles this case explicitely for RT and falls back to do_softirq() on !RT kernels. In the RT case this warns when one of the flushed SMP function calls raised a soft interrupt so this can be investigated. [ tglx: Moved the RT part out of SMP code ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/YgKgL6aPj8aBES6G@linutronix.de Link: https://lore.kernel.org/r/20220413133024.356509586@linutronix.de
* | lockdep: Delete local_irq_enable_in_hardirq()Thomas Gleixner2022-05-111-18/+0
|/ | | | | | | | No more users and there is no desire to grow new ones. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/8735hir0j4.ffs@tglx
* lib/irq_poll: Declare IRQ_POLL softirq vector as ksoftirqd-parking safeFrederic Weisbecker2022-03-071-4/+7
| | | | | | | | | | | | | | | | | | | | | The following warning may appear while setting a CPU down: NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #20!!! The IRQ_POLL_SOFTIRQ vector can be raised during the hotplug cpu_down() path after ksoftirqd is parked and before the CPU actually dies. However this is handled afterward at the CPUHP_IRQ_POLL_DEAD stage where the queue gets migrated. Hence this warning can be considered spurious and the vector can join the "hotplug-safe" list. Reported-and-tested-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
* tick/rcu: Stop allowing RCU_SOFTIRQ in idleFrederic Weisbecker2022-03-071-1/+7
| | | | | | | | | | | | | | | | | | | | | RCU_SOFTIRQ used to be special in that it could be raised on purpose within the idle path to prevent from stopping the tick. Some code still prevents from unnecessary warnings related to this specific behaviour while entering in dynticks-idle mode. However the nohz layout has changed quite a bit in ten years, and the removal of CONFIG_RCU_FAST_NO_HZ has been the final straw to this safe-conduct. Now the RCU_SOFTIRQ vector is expected to be raised from sane places. A remaining corner case is admitted though when the vector is invoked in fragile hotplug path. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Menzel <pmenzel@molgen.mpg.de>
* genirq: Provide new interfaces for affinity hintsThomas Gleixner2021-12-101-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The discussion about removing the side effect of irq_set_affinity_hint() of actually applying the cpumask (if not NULL) as affinity to the interrupt, unearthed a few unpleasantries: 1) The modular perf drivers rely on the current behaviour for the very wrong reasons. 2) While none of the other drivers prevents user space from changing the affinity, a cursorily inspection shows that there are at least expectations in some drivers. #1 needs to be cleaned up anyway, so that's not a problem #2 might result in subtle regressions especially when irqbalanced (which nowadays ignores the affinity hint) is disabled. Provide new interfaces: irq_update_affinity_hint() - Only sets the affinity hint pointer irq_set_affinity_and_hint() - Set the pointer and apply the affinity to the interrupt Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and document it to be phased out. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
* genirq: Change force_irqthreads to a static keyTanner Love2021-08-101-3/+5
| | | | | | | | | | | | | | | | | With CONFIG_IRQ_FORCED_THREADING=y, testing the boolean force_irqthreads could incur a cache line miss in invoke_softirq() and other places. Replace the test with a static key to avoid the potential cache miss. [ tglx: Dropped the IDE part, removed the export and updated blk-mq ] Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Tanner Love <tannerlove@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210602180338.3324213-1-tannerlove.kernel@gmail.com
* Merge branch 'irq/affinity' into irq/coreThomas Gleixner2021-05-191-33/+2
|\ | | | | | | | | Merge the export of irq_set_affinity() which is a standalone commit so it can be pulled into other trees.
| * genirq: Export affinity setter for modulesThomas Gleixner2021-05-191-33/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Perf modules abuse irq_set_affinity_hint() to set the affinity of system PMU interrupts just because irq_set_affinity() was not exported. The fact that irq_set_affinity_hint() actually sets the affinity is a non-documented side effect and the name is clearly saying it's a hint. To clean this up, export the real affinity setter. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210518093117.968251441@linutronix.de
* | genirq: Add a IRQF_NO_DEBUG flagThomas Gleixner2021-05-171-0/+3
|/ | | | | | | | | | | | | | | | | | | | The whole call to note_interrupt() can be avoided or return early when interrupts would be marked accordingly. For IPI handlers which always return HANDLED the whole procedure is pretty pointless to begin with. Add a IRQF_NO_DEBUG flag and mark the interrupt accordingly if supplied when the interrupt is requested. When noirqdebug is set on the kernel commandline, then the interrupt is marked unconditionally so that there is only one condition in the hotpath to evaluate. [ clg: Add changelog ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/7a8ad02f-63a8-c1aa-fdd1-39d973593d02@kaod.org
* tasklets: Switch tasklet_disable() to the sleep wait variantThomas Gleixner2021-03-171-2/+1
| | | | | | | | | | | | -- NOT FOR IMMEDIATE MERGING -- Now that all users of tasklet_disable() are invoked from sleepable context, convert it to use tasklet_unlock_wait() which might sleep. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084242.726452321@linutronix.de
* tasklets: Prevent tasklet_unlock_spin_wait() deadlock on RTThomas Gleixner2021-03-171-10/+2
| | | | | | | | | | | | | | | | | | | | | | tasklet_unlock_spin_wait() spin waits for the TASKLET_STATE_SCHED bit in the tasklet state to be cleared. This works on !RT nicely because the corresponding execution can only happen on a different CPU. On RT softirq processing is preemptible, therefore a task preempting the softirq processing thread can spin forever. Prevent this by invoking local_bh_disable()/enable() inside the loop. In case that the softirq processing thread was preempted by the current task, current will block on the local lock which yields the CPU to the preempted softirq processing thread. If the tasklet is processed on a different CPU then the local_bh_disable()/enable() pair is just a waste of processor cycles. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.988908275@linutronix.de
* tasklets: Replace spin wait in tasklet_unlock_wait()Peter Zijlstra2021-03-171-11/+2
| | | | | | | | | | | | | | | | | | | | | tasklet_unlock_wait() spin waits for TASKLET_STATE_RUN to be cleared. This is wasting CPU cycles in a tight loop which is especially painful in a guest when the CPU running the tasklet is scheduled out. tasklet_unlock_wait() is invoked from tasklet_kill() which is used in teardown paths and not performance critical at all. Replace the spin wait with wait_var_event(). There are no users of tasklet_unlock_wait() which are invoked from atomic contexts. The usage in tasklet_disable() has been replaced temporarily with the spin waiting variant until the atomic users are fixed up and will be converted to the sleep wait variant later. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.783936921@linutronix.de
* tasklets: Use spin wait in tasklet_disable() temporarilyThomas Gleixner2021-03-171-1/+2
| | | | | | | | | | To ease the transition use spin waiting in tasklet_disable() until all usage sites from atomic context have been cleaned up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.685352806@linutronix.de
* tasklets: Provide tasklet_disable_in_atomic()Thomas Gleixner2021-03-171-0/+22
| | | | | | | | | | | | | | | | Replacing the spin wait loops in tasklet_unlock_wait() with wait_var_event() is not possible as a handful of tasklet_disable() invocations are happening in atomic context. All other invocations are in teardown paths which can sleep. Provide tasklet_disable_in_atomic() and tasklet_unlock_spin_wait() to convert the few atomic use cases over, which allows to change tasklet_disable() and tasklet_unlock_wait() in a later step. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.563164193@linutronix.de
* tasklets: Use static inlines for stub implementationsThomas Gleixner2021-03-171-3/+3
| | | | | | | | | | Inlines exist for a reason. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.407702697@linutronix.de
* tasklets: Replace barrier() with cpu_relax() in tasklet_unlock_wait()Thomas Gleixner2021-03-171-1/+2
| | | | | | | | | | | | A barrier() in a tight loop which waits for something to happen on a remote CPU is a pointless exercise. Replace it with cpu_relax() which allows HT siblings to make progress. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210309084241.249343366@linutronix.de
* tasklet: Remove tasklet_kill_immediateDavidlohr Bueso2021-03-161-1/+0
| | | | | | | | | | Ever since RCU was converted to softirq, it has no users. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20210306213658.12862-1-dave@stgolabs.net
* genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()Barry Song2021-03-061-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many drivers don't want interrupts enabled automatically via request_irq(). So they are handling this issue by either way of the below two: (1) irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); (2) request_irq(dev, irq...); disable_irq(irq); The code in the second way is silly and unsafe. In the small time gap between request_irq() and disable_irq(), interrupts can still come. The code in the first way is safe though it's subobtimal. Add a new IRQF_NO_AUTOEN flag which can be handed in by drivers to request_irq() and request_nmi(). It prevents the automatic enabling of the requested interrupt/nmi in the same safe way as #1 above. With that the various usage sites of #1 and #2 above can be simplified and corrected. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: dmitry.torokhov@gmail.com Link: https://lore.kernel.org/r/20210302224916.13980-2-song.bao.hua@hisilicon.com
* softirq: Move do_softirq_own_stack() to generic asm headerThomas Gleixner2021-02-101-9/+0
| | | | | | | | | | | | | | | To avoid include recursion hell move the do_softirq_own_stack() related content into a generic asm header and include it from all places in arch/ which need the prototype. This allows architectures to provide an inline implementation of do_softirq_own_stack() without introducing a lot of #ifdeffery all over the place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de
* softirq: Move __ARCH_HAS_DO_SOFTIRQ to KconfigThomas Gleixner2021-02-101-1/+1
| | | | | | | | | | | | | | | To prepare for inlining do_softirq_own_stack() replace __ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected architectures. This allows in the next step to move the function prototype and the inline stub into a seperate asm-generic header file which is required to avoid include recursion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
* genirq: Move irq_has_action() into core codeThomas Gleixner2020-12-151-0/+1
| | | | | | | | | | | | | | This function uses irq_to_desc() and is going to be used by modules to replace the open coded irq_to_desc() (ab)usage. The final goal is to remove the export of irq_to_desc() so driver cannot fiddle with it anymore. Move it into the core code and fixup the usage sites to include the proper header. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201210194042.548936472@linutronix.de
* genirq/affinity: Add irq_update_affinity_desc()John Garry2020-12-111-0/+8
| | | | | | | | | | | | | | | | | | | | Add a function to allow the affinity of an interrupt be switched to managed, such that interrupts allocated for platform devices may be managed. This new interface has certain limitations, and attempts to use it in the following circumstances will fail: - For when the kernel is configured for generic IRQ reservation mode (in config GENERIC_IRQ_RESERVATION_MODE). The reason being that it could conflict with managed vs. non-managed interrupt accounting. - The interrupt is already started, which should not be the case during init - The interrupt is already configured as managed, which means double init Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1606905417-183214-2-git-send-email-john.garry@huawei.com
* treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches2020-10-251-2/+2
| | | | | | | | | | | | | | | | | | | | Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tasklet: Introduce new initialization APIRomain Perier2020-07-301-1/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nowadays, modern kernel subsystems that use callbacks pass the data structure associated with a given callback as argument to the callback. The tasklet subsystem remains one which passes an arbitrary unsigned long to the callback function. This has several problems: - This keeps an extra field for storing the argument in each tasklet data structure, it bloats the tasklet_struct structure with a redundant .data field - No type checking can be performed on this argument. Instead of using container_of() like other callback subsystems, it forces callbacks to do explicit type cast of the unsigned long argument into the required object type. - Buffer overflows can overwrite the .func and the .data field, so an attacker can easily overwrite the function and its first argument to whatever it wants. Add a new tasklet initialization API, via DECLARE_TASKLET() and tasklet_setup(), which will replace the existing ones. This work is greatly inspired by the timer_struct conversion series, see commit e99e88a9d2b0 ("treewide: setup_timer() -> timer_setup()") To avoid problems with both -Wcast-function-type (which is enabled in the kernel via -Wextra is several subsystems), and with mismatched function prototypes when build with Control Flow Integrity enabled, this adds the "use_callback" member to let the tasklet caller choose which union member to call through. Once all old API uses are removed, this and the .data member will be removed as well. (On 64-bit this does not grow the struct size as the new member fills the hole after atomic_t, which is also "int" sized.) Signed-off-by: Romain Perier <romain.perier@gmail.com> Co-developed-by: Allen Pais <allen.lkml@gmail.com> Signed-off-by: Allen Pais <allen.lkml@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()Kees Cook2020-07-301-5/+10
| | | | | | | | | | | This converts all the existing DECLARE_TASKLET() (and ...DISABLED) macros with DECLARE_TASKLET_OLD() in preparation for refactoring the tasklet callback type. All existing DECLARE_TASKLET() users had a "0" data argument, it has been removed here as well. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kees Cook <keescook@chromium.org>
* x86/entry: Unbreak __irqentry_text_start/end magicThomas Gleixner2020-06-111-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | The entry rework moved interrupt entry code from the irqentry to the noinstr section which made the irqentry section empty. This breaks boundary checks which rely on the __irqentry_text_start/end markers to find out whether a function in a stack trace is interrupt/exception entry code. This affects the function graph tracer and filter_irq_stacks(). As the IDT entry points are all sequentialy emitted this is rather simple to unbreak by injecting __irqentry_text_start/end as global labels. To make this work correctly: - Remove the IRQENTRY_TEXT section from the x86 linker script - Define __irqentry so it breaks the build if it's used - Adjust the entry mirroring in PTI - Remove the redundant kprobes and unwinder bound checks Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Provide interrupt injection mechanismThomas Gleixner2020-03-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Error injection mechanisms need a half ways safe way to inject interrupts as invoking generic_handle_irq() or the actual device interrupt handler directly from e.g. a debugfs write is not guaranteed to be safe. On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which is the base of x86 interrupt delivery and affinity management. Move the irq debugfs injection code into a separate function which can be used by error injection code as well. The implementation prevents at least that state is corrupted, but it cannot close a very tiny race window on x86 which might result in a stale and not serviced device interrupt under very unlikely circumstances. This is explicitly for debugging and testing and not for production use or abuse in random driver code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de
* Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2019-12-031-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Ingo Molnar: "The main changes in the timer code in this cycle were: - Clockevent updates: - timer-of framework cleanups. (Geert Uytterhoeven) - Use timer-of for the renesas-ostm and the device name to prevent name collision in case of multiple timers. (Geert Uytterhoeven) - Check if there is an error after calling of_clk_get in asm9260 (Chuhong Yuan) - ABI fix: Zero out high order bits of nanoseconds on compat syscalls. This got broken a year ago, with apparently no side effects so far. Since the kernel would use random data otherwise I don't think we'd have other options but to fix the bug, even if there was a side effect to applications (Dmitry Safonov) - Optimize ns_to_timespec64() on 32-bit systems: move away from div_s64_rem() which can be slow, to div_u64_rem() which is faster (Arnd Bergmann) - Annotate KCSAN-reported false positive data races in hrtimer_is_queued() users by moving timer->state handling over to the READ_ONCE()/WRITE_ONCE() APIs. This documents these accesses (Eric Dumazet) - Misc cleanups and small fixes" [ I undid the "ABI fix" and updated the comments instead. The reason there were apparently no side effects is that the fix was a no-op. The updated comment is to say _why_ it was a no-op. - Linus ] * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Zero the upper 32-bits in __kernel_timespec on 32-bit time: Rename tsk->real_start_time to ->start_boottime hrtimer: Remove the comment about not used HRTIMER_SOFTIRQ time: Fix spelling mistake in comment time: Optimize ns_to_timespec64() hrtimer: Annotate lockless access to timer->state clocksource/drivers/asm9260: Add a check for of_clk_get clocksource/drivers/renesas-ostm: Use unique device name instead of ostm clocksource/drivers/renesas-ostm: Convert to timer_of clocksource/drivers/timer-of: Use unique device name instead of timer clocksource/drivers/timer-of: Convert last full_name to %pOF
| * hrtimer: Remove the comment about not used HRTIMER_SOFTIRQSebastian Andrzej Siewior2019-11-121-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The softirq `HRTIMER_SOFTIRQ' was not used since commit c6eb3f70d448 ("hrtimer: Get rid of hrtimer softirq"). But it got used again, beginning with commit 5da70160462e ("hrtimer: Implement support for softirq based hrtimers"), which did not remove the comment. Remove it now. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191107091924.13410-1-bigeasy@linutronix.de
* | docs: Add request_irq() documentationJonathan Corbet2019-11-181-0/+13
|/ | | | | | | | | | While checking the results of the :c:func: removal, I noticed that there was no documentation for request_irq(), and request_threaded_irq() was not mentioned at all. Add a kerneldoc comment for request_irq() and add request_threaded_irq() to the list of functions. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Merge tag 'pm-5.4-rc1' of ↵Linus Torvalds2019-09-171-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These include a rework of the main suspend-to-idle code flow (related to the handling of spurious wakeups), a switch over of several users of cpufreq notifiers to QoS-based limits, a new devfreq driver for Tegra20, a new cpuidle driver and governor for virtualized guests, an extension of the wakeup sources framework to expose wakeup sources as device objects in sysfs, and more. Specifics: - Rework the main suspend-to-idle control flow to avoid repeating "noirq" device resume and suspend operations in case of spurious wakeups from the ACPI EC and decouple the ACPI EC wakeups support from the LPS0 _DSM support (Rafael Wysocki). - Extend the wakeup sources framework to expose wakeup sources as device objects in sysfs (Tri Vo, Stephen Boyd). - Expose system suspend statistics in sysfs (Kalesh Singh). - Introduce a new haltpoll cpuidle driver and a new matching governor for virtualized guests wanting to do guest-side polling in the idle loop (Marcelo Tosatti, Joao Martins, Wanpeng Li, Stephen Rothwell). - Fix the menu and teo cpuidle governors to allow the scheduler tick to be stopped if PM QoS is used to limit the CPU idle state exit latency in some cases (Rafael Wysocki). - Increase the resolution of the play_idle() argument to microseconds for more fine-grained injection of CPU idle cycles (Daniel Lezcano). - Switch over some users of cpuidle notifiers to the new QoS-based frequency limits and drop the CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events (Viresh Kumar). - Add new cpufreq driver based on nvmem for sun50i (Yangtao Li). - Add support for MT8183 and MT8516 to the mediatek cpufreq driver (Andrew-sh.Cheng, Fabien Parent). - Add i.MX8MN support to the imx-cpufreq-dt cpufreq driver (Anson Huang). - Add qcs404 to cpufreq-dt-platdev blacklist (Jorge Ramirez-Ortiz). - Update the qcom cpufreq driver (among other things, to make it easier to extend and to use kryo cpufreq for other nvmem-based SoCs) and add qcs404 support to it (Niklas Cassel, Douglas RAILLARD, Sibi Sankar, Sricharan R). - Fix assorted issues and make assorted minor improvements in the cpufreq code (Colin Ian King, Douglas RAILLARD, Florian Fainelli, Gustavo Silva, Hariprasad Kelam). - Add new devfreq driver for NVidia Tegra20 (Dmitry Osipenko, Arnd Bergmann). - Add new Exynos PPMU events to devfreq events and extend that mechanism (Lukasz Luba). - Fix and clean up the exynos-bus devfreq driver (Kamil Konieczny). - Improve devfreq documentation and governor code, fix spelling typos in devfreq (Ezequiel Garcia, Krzysztof Kozlowski, Leonard Crestez, MyungJoo Ham, Gaël PORTAY). - Add regulators enable and disable to the OPP (operating performance points) framework (Kamil Konieczny). - Update the OPP framework to support multiple opp-suspend properties (Anson Huang). - Fix assorted issues and make assorted minor improvements in the OPP code (Niklas Cassel, Viresh Kumar, Yue Hu). - Clean up the generic power domains (genpd) framework (Ulf Hansson). - Clean up assorted pieces of power management code and documentation (Akinobu Mita, Amit Kucheria, Chuhong Yuan). - Update the pm-graph tool to version 5.5 including multiple fixes and improvements (Todd Brandt). - Update the cpupower utility (Benjamin Weis, Geert Uytterhoeven, Sébastien Szymanski)" * tag 'pm-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (126 commits) cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available cpuidle-haltpoll: do not set an owner to allow modunload cpuidle-haltpoll: return -ENODEV on modinit failure cpuidle-haltpoll: set haltpoll as preferred governor cpuidle: allow governor switch on cpuidle_register_driver() PM: runtime: Documentation: add runtime_status ABI document pm-graph: make setVal unbuffered again for python2 and python3 powercap: idle_inject: Use higher resolution for idle injection cpuidle: play_idle: Increase the resolution to usec cpuidle-haltpoll: vcpu hotplug support cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist cpufreq: qcom: Add support for qcs404 on nvmem driver cpufreq: qcom: Refactor the driver to make it easier to extend cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem based qcom socs dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR dt-bindings: opp: qcom-nvmem: Support pstates provided by a power domain Documentation: cpufreq: Update policy notifier documentation cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events PM / Domains: Verify PM domain type in dev_pm_genpd_set_performance_state() PM / Domains: Simplify genpd_lookup_dev() ...
| * PCI: irq: Introduce rearm_wake_irq()Rafael J. Wysocki2019-07-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new function, rearm_wake_irq(), allowing a wakeup IRQ to be armed for systen wakeup detection again without running any action handlers associated with it after it has been armed for wakeup detection and triggered. That is useful for IRQs, like ACPI SCI, that may deliver wakeup as well as non-wakeup interrupts when armed for systen wakeup detection. In those cases, it may be possible to determine whether or not the delivered interrupt is a systen wakeup one without running the entire action handler (or handlers, if the IRQ is shared) for the IRQ, and if the interrupt turns out to be a non-wakeup one, the IRQ can be rearmed with the help of the new function. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Force interrupt threading on RTThomas Gleixner2019-08-191-0/+4
|/ | | | | | | | | | | Switch force_irqthreads from a boot time modifiable variable to a compile time constant when CONFIG_PREEMPT_RT is enabled. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190816160923.12855-1-bigeasy@linutronix.de
* docs: power: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2019-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | Convert the PM documents to ReST, in order to allow them to build with Sphinx. The conversion is actually: - add blank lines and indentation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
* softirq: Remove tasklet_hrtimerThomas Gleixner2019-03-221-25/+0
| | | | | | | | | | | | | There are no more users of this interface. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Link: https://lkml.kernel.org/r/20190301224821.29843-4-bigeasy@linutronix.de
* Merge tag 'irqchip-5.1' of ↵Thomas Gleixner2019-02-231-0/+18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull irqchip updates from Marc Zyngier - Core pseudo-NMI handling code - Allow the default irq domain to be retrieved - A new interrupt controller for the Loongson LS1X platform - Affinity support for the SiFive PLIC - Better support for the iMX irqsteer driver - NUMA aware memory allocations for GICv3 - A handful of other fixes (i8259, GICv3, PLIC)
| * genirq: Provide NMI management for percpu_devid interruptsJulien Thierry2019-02-051-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for percpu_devid interrupts treated as NMIs. Percpu_devid NMIs need to be setup/torn down on each CPU they target. The same restrictions as for global NMIs still apply for percpu_devid NMIs. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| * genirq: Provide basic NMI management for interrupt linesJulien Thierry2019-02-051-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functionality to allocate interrupt lines that will deliver IRQs as Non-Maskable Interrupts. These allocations are only successful if the irqchip provides the necessary support and allows NMI delivery for the interrupt line. Interrupt lines allocated for NMI delivery must be enabled/disabled through enable_nmi/disable_nmi_nosync to keep their state consistent. To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded, the irqchip directly managing the IRQ must be the root irqchip and the irqchip cannot be behind a slow bus. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* | genirq/affinity: Add new callback for (re)calculating interrupt setsMing Lei2019-02-181-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The interrupt affinity spreading mechanism supports to spread out affinities for one or more interrupt sets. A interrupt set contains one or more interrupts. Each set is mapped to a specific functionality of a device, e.g. general I/O queues and read I/O queus of multiqueue block devices. The number of interrupts per set is defined by the driver. It depends on the total number of available interrupts for the device, which is determined by the PCI capabilites and the availability of underlying CPU resources, and the number of queues which the device provides and the driver wants to instantiate. The driver passes initial configuration for the interrupt allocation via a pointer to struct irq_affinity. Right now the allocation mechanism is complex as it requires to have a loop in the driver to determine the maximum number of interrupts which are provided by the PCI capabilities and the underlying CPU resources. This loop would have to be replicated in every driver which wants to utilize this mechanism. That's unwanted code duplication and error prone. In order to move this into generic facilities it is required to have a mechanism, which allows the recalculation of the interrupt sets and their size, in the core code. As the core code does not have any knowledge about the underlying device, a driver specific callback is required in struct irq_affinity, which can be invoked by the core code. The callback gets the number of available interupts as an argument, so the driver can calculate the corresponding number and size of interrupt sets. At the moment the struct irq_affinity pointer which is handed in from the driver and passed through to several core functions is marked 'const', but for the callback to be able to modify the data in the struct it's required to remove the 'const' qualifier. Add the optional callback to struct irq_affinity, which allows drivers to recalculate the number and size of interrupt sets and remove the 'const' qualifier. For simple invocations, which do not supply a callback, a default callback is installed, which just sets nr_sets to 1 and transfers the number of spreadable vectors to the set_size array at index 0. This is for now guarded by a check for nr_sets != 0 to keep the NVME driver working until it is converted to the callback mechanism. To make sure that the driver configuration is correct under all circumstances the callback is invoked even when there are no interrupts for queues left, i.e. the pre/post requirements already exhaust the numner of available interrupts. At the PCI layer irq_create_affinity_masks() has to be invoked even for the case where the legacy interrupt is used. That ensures that the callback is invoked and the device driver can adjust to that situation. [ tglx: Fixed the simple case (no sets required). Moved the sanity check for nr_sets after the invocation of the callback so it catches broken drivers. Fixed the kernel doc comments for struct irq_affinity and de-'This patch'-ed the changelog ] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch <keith.busch@intel.com> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com> Link: https://lkml.kernel.org/r/20190216172228.512444498@linutronix.de
* | genirq/affinity: Store interrupt sets size in struct irq_affinityMing Lei2019-02-181-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The interrupt affinity spreading mechanism supports to spread out affinities for one or more interrupt sets. A interrupt set contains one or more interrupts. Each set is mapped to a specific functionality of a device, e.g. general I/O queues and read I/O queus of multiqueue block devices. The number of interrupts per set is defined by the driver. It depends on the total number of available interrupts for the device, which is determined by the PCI capabilites and the availability of underlying CPU resources, and the number of queues which the device provides and the driver wants to instantiate. The driver passes initial configuration for the interrupt allocation via a pointer to struct irq_affinity. Right now the allocation mechanism is complex as it requires to have a loop in the driver to determine the maximum number of interrupts which are provided by the PCI capabilities and the underlying CPU resources. This loop would have to be replicated in every driver which wants to utilize this mechanism. That's unwanted code duplication and error prone. In order to move this into generic facilities it is required to have a mechanism, which allows the recalculation of the interrupt sets and their size, in the core code. As the core code does not have any knowledge about the underlying device, a driver specific callback will be added to struct affinity_desc, which will be invoked by the core code. The callback will get the number of available interupts as an argument, so the driver can calculate the corresponding number and size of interrupt sets. To support this, two modifications for the handling of struct irq_affinity are required: 1) The (optional) interrupt sets size information is contained in a separate array of integers and struct irq_affinity contains a pointer to it. This is cumbersome and as the maximum number of interrupt sets is small, there is no reason to have separate storage. Moving the size array into struct affinity_desc avoids indirections and makes the code simpler. 2) At the moment the struct irq_affinity pointer which is handed in from the driver and passed through to several core functions is marked 'const'. With the upcoming callback to recalculate the number and size of interrupt sets, it's necessary to remove the 'const' qualifier. Otherwise the callback would not be able to update the data. Implement #1 and store the interrupt sets size in 'struct irq_affinity'. No functional change. [ tglx: Fixed the memcpy() size so it won't copy beyond the size of the source. Fixed the kernel doc comments for struct irq_affinity and de-'This patch'-ed the changelog ] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch <keith.busch@intel.com> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com> Link: https://lkml.kernel.org/r/20190216172228.423723127@linutronix.de
* | genirq/affinity: Code consolidationThomas Gleixner2019-02-181-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All information and calculations in the interrupt affinity spreading code is strictly unsigned int. Though the code uses int all over the place. Convert it over to unsigned int. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch <keith.busch@intel.com> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com> Link: https://lkml.kernel.org/r/20190216172228.336424556@linutronix.de
* | genirq: Fix the kerneldoc comment for struct irq_affinity_descJonathan Corbet2019-01-181-0/+1
|/ | | | | | | | | | | | | | | A recent commit added a new field but did not update the kerneldoc comment, leading to this build warning: ./include/linux/interrupt.h:268: warning: Function parameter or member 'is_managed' not described in 'irq_affinity_desc' Add the missing information, making the docs build 0.001% quieter. Fixes: c410abbbacb9 ("genirq/affinity: Add is_managed to struct irq_affinity_desc") Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dou Liyang <douliyangs@gmail.com> Link: https://lkml.kernel.org/r/20190108170432.59bae8a6@lwn.net
* genirq/affinity: Add is_managed to struct irq_affinity_descDou Liyang2018-12-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. That limitation was reported by Kashyap and Sumit. Expand struct irq_affinity_desc with a new bit 'is_managed' which is set for truly managed interrupts (queue interrupts) and cleared for the general device interrupts. [ tglx: Simplify code and massage changelog ] Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Reported-by: Sumit Saxena <sumit.saxena@broadcom.com> Signed-off-by: Dou Liyang <douliyangs@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-pci@vger.kernel.org Cc: shivasharan.srikanteshwara@broadcom.com Cc: ming.lei@redhat.com Cc: hch@lst.de Cc: bhelgaas@google.com Cc: douliyang1@huawei.com Link: https://lkml.kernel.org/r/20181204155122.6327-3-douliyangs@gmail.com
* genirq/core: Introduce struct irq_affinity_descDou Liyang2018-12-191-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The interrupt affinity management uses straight cpumask pointers to convey the automatically assigned affinity masks for managed interrupts. The core interrupt descriptor allocation also decides based on the pointer being non NULL whether an interrupt is managed or not. Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. To remedy that situation it's required to convey more information than the cpumasks through various interfaces related to interrupt descriptor allocation. Instead of adding yet another argument, create a new data structure 'irq_affinity_desc' which for now just contains the cpumask. This struct can be expanded to convey auxilliary information in the next step. No functional change, just preparatory work. [ tglx: Simplified logic and clarified changelog ] Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dou Liyang <douliyangs@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-pci@vger.kernel.org Cc: kashyap.desai@broadcom.com Cc: shivasharan.srikanteshwara@broadcom.com Cc: sumit.saxena@broadcom.com Cc: ming.lei@redhat.com Cc: hch@lst.de Cc: douliyang1@huawei.com Link: https://lkml.kernel.org/r/20181204155122.6327-2-douliyangs@gmail.com
* genirq/affinity: Add support for allocating interrupt setsJens Axboe2018-11-051-0/+4
| | | | | | | | | | | | | | | | | | | | | A driver may have a need to allocate multiple sets of MSI/MSI-X interrupts, and have them appropriately affinitized. Add support for defining a number of sets in the irq_affinity structure, of varying sizes, and get each set affinitized correctly across the machine. [ tglx: Minor changelog tweaks ] Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Cc: linux-block@vger.kernel.org Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com
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