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* locking/lockdep: Add 'crossrelease' feature documentationByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | This document describes the concept of crossrelease feature. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-15-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Apply crossrelease to completionsByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | Although wait_for_completion() and its family can cause deadlock, the lock correctness validator could not be applied to them until now, because things like complete() are usually called in a different context from the waiting context, which violates lockdep's assumption. Thanks to CONFIG_LOCKDEP_CROSSRELEASE, we can now apply the lockdep detector to those completion operations. Applied it. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-10-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Make print_circular_bug() aware of crossreleaseByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | print_circular_bug() reporting circular bug assumes that target hlock is owned by the current. However, in crossrelease, target hlock can be owned by other than the current. So the report format needs to be changed to reflect the change. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Handle non(or multi)-acquisition of a crosslockByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No acquisition might be in progress on commit of a crosslock. Completion operations enabling crossrelease are the case like: CONTEXT X CONTEXT Y --------- --------- trigger completion context complete AX commit AX wait_for_complete AX acquire AX wait where AX is a crosslock. When no acquisition is in progress, we should not perform commit because the lock does not exist, which might cause incorrect memory access. So we have to track the number of acquisitions of a crosslock to handle it. Moreover, in case that more than one acquisition of a crosslock are overlapped like: CONTEXT W CONTEXT X CONTEXT Y CONTEXT Z --------- --------- --------- --------- acquire AX (gen_id: 1) acquire A acquire AX (gen_id: 10) acquire B commit AX acquire C commit AX where A, B and C are typical locks and AX is a crosslock. Current crossrelease code performs commits in Y and Z with gen_id = 10. However, we can use gen_id = 1 to do it, since not only 'acquire AX in X' but 'acquire AX in W' also depends on each acquisition in Y and Z until their commits. So make it use gen_id = 1 instead of 10 on their commits, which adds an additional dependency 'AX -> A' in the example above. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-8-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Detect and handle hist_lock ring buffer overwriteByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring buffer can be overwritten by hardirq/softirq/work contexts. That cases must be considered on rollback or commit. For example, |<------ hist_lock ring buffer size ----->| ppppppppppppiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii wrapped > iiiiiiiiiiiiiiiiiiiiiii.................... where 'p' represents an acquisition in process context, 'i' represents an acquisition in irq context. On irq exit, crossrelease tries to rollback idx to original position, but it should not because the entry already has been invalid by overwriting 'i'. Avoid rollback or commit for entries overwritten. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-7-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Implement the 'crossrelease' featureByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep is a runtime locking correctness validator that detects and reports a deadlock or its possibility by checking dependencies between locks. It's useful since it does not report just an actual deadlock but also the possibility of a deadlock that has not actually happened yet. That enables problems to be fixed before they affect real systems. However, this facility is only applicable to typical locks, such as spinlocks and mutexes, which are normally released within the context in which they were acquired. However, synchronization primitives like page locks or completions, which are allowed to be released in any context, also create dependencies and can cause a deadlock. So lockdep should track these locks to do a better job. The 'crossrelease' implementation makes these primitives also be tracked. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-6-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Make check_prev_add() able to handle external stack_traceByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently, a space for stack_trace is pinned in check_prev_add(), that makes us not able to use external stack_trace. The simplest way to achieve it is to pass an external stack_trace as an argument. A more suitable solution is to pass a callback additionally along with a stack_trace so that callers can decide the way to save or whether to save. Actually crossrelease needs to do other than saving a stack_trace. So pass a stack_trace and callback to handle it, to check_prev_add(). Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-5-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Change the meaning of check_prev_add()'s return valueByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | Firstly, return 1 instead of 2 when 'prev -> next' dependency already exists. Since the value 2 is not referenced anywhere, just return 1 indicating success in this case. Secondly, return 2 instead of 1 when successfully added a lock_list entry with saving stack_trace. With that, a caller can decide whether to avoid redundant save_trace() on the caller site. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-4-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Add a function building a chain between two classesByungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | Crossrelease needs to build a chain between two classes regardless of their contexts. However, add_chain_cache() cannot be used for that purpose since it assumes that it's called in the acquisition context of the hlock. So this patch introduces a new function doing it. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-3-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Refactor lookup_chain_cache()Byungchul Park2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | Currently, lookup_chain_cache() provides both 'lookup' and 'add' functionalities in a function. However, each is useful. So this patch makes lookup_chain_cache() only do 'lookup' functionality and makes add_chain_cahce() only do 'add' functionality. And it's more readable than before. Signed-off-by: Byungchul Park <byungchul.park@lge.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: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-2-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Avoid creating redundant linksPeter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two boots + a make defconfig, the first didn't have the redundant bit in, the second did: lock-classes: 1168 1169 [max: 8191] direct dependencies: 7688 5812 [max: 32768] indirect dependencies: 25492 25937 all direct dependencies: 220113 217512 dependency chains: 9005 9008 [max: 65536] dependency chain hlocks: 34450 34366 [max: 327680] in-hardirq chains: 55 51 in-softirq chains: 371 378 in-process chains: 8579 8579 stack-trace entries: 108073 88474 [max: 524288] combined max dependencies: 178738560 169094640 max locking depth: 15 15 max bfs queue depth: 320 329 cyclic checks: 9123 9190 redundant checks: 5046 redundant links: 1828 find-mask forwards checks: 2564 2599 find-mask backwards checks: 39521 39789 So it saves nearly 2k links and a fair chunk of stack-trace entries, but as expected, makes no real difference on the indirect dependencies. At the same time, you see the max BFS depth increase, which is also expected, although it could easily be boot variance -- these numbers are not entirely stable between boots. The down side is that the cycles in the graph become larger and thus the reports harder to read. XXX: do we want this as a CONFIG variable, implied by LOCKDEP_SMALL? Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: iamjoonsoo.kim@lge.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Link: http://lkml.kernel.org/r/20170303091338.GH6536@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/lockdep: Rework FS_RECLAIM annotationPeter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A while ago someone, and I cannot find the email just now, asked if we could not implement the RECLAIM_FS inversion stuff with a 'fake' lock like we use for other things like workqueues etc. I think this should be possible which allows reducing the 'irq' states and will reduce the amount of __bfs() lookups we do. Removing the 1 IRQ state results in 4 less __bfs() walks per dependency, improving lockdep performance. And by moving this annotation out of the lockdep code it becomes easier for the mm people to extend. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: iamjoonsoo.kim@lge.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking: Remove smp_mb__before_spinlock()Peter Zijlstra2017-08-10
| | | | | | | | | | | Now that there are no users of smp_mb__before_spinlock() left, remove it entirely. 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> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking: Introduce smp_mb__after_spinlock()Peter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since its inception, our understanding of ACQUIRE, esp. as applied to spinlocks, has changed somewhat. Also, I wonder if, with a simple change, we cannot make it provide more. The problem with the comment is that the STORE done by spin_lock isn't itself ordered by the ACQUIRE, and therefore a later LOAD can pass over it and cross with any prior STORE, rendering the default WMB insufficient (pointed out by Alan). Now, this is only really a problem on PowerPC and ARM64, both of which already defined smp_mb__before_spinlock() as a smp_mb(). At the same time, we can get a much stronger construct if we place that same barrier _inside_ the spin_lock(). In that case we upgrade the RCpc spinlock to an RCsc. That would make all schedule() calls fully transitive against one another. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* overlayfs, locking: Remove smp_mb__before_spinlock() usagePeter Zijlstra2017-08-10
| | | | | | | | | | | | | | | While we could replace the smp_mb__before_spinlock() with the new smp_mb__after_spinlock(), the normal pattern is to use smp_store_release() to publish an object that is used for lockless_dereference() -- and mirrors the regular rcu_assign_pointer() / rcu_dereference() patterns. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm, locking: Rework {set,clear,mm}_tlb_flush_pending()Peter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit: af2c1401e6f9 ("mm: numa: guarantee that tlb_flush_pending updates are visible before page table updates") added smp_mb__before_spinlock() to set_tlb_flush_pending(). I think we can solve the same problem without this barrier. If instead we mandate that mm_tlb_flush_pending() is used while holding the PTL we're guaranteed to observe prior set_tlb_flush_pending() instances. For this to work we need to rework migrate_misplaced_transhuge_page() a little and move the test up into do_huge_pmd_numa_page(). NOTE: this relies on flush_tlb_range() to guarantee: (1) it ensures that prior page table updates are visible to the page table walker and (2) it ensures that subsequent memory accesses are only made visible after the invalidation has completed This is required for architectures that implement TRANSPARENT_HUGEPAGE (arc, arm, arm64, mips, powerpc, s390, sparc, x86) or otherwise use mm_tlb_flush_pending() in their page-table operations (arm, arm64, x86). This appears true for: - arm (DSB ISB before and after), - arm64 (DSB ISHST before, and DSB ISH after), - powerpc (PTESYNC before and after), - s390 and x86 TLB invalidate are serializing instructions But I failed to understand the situation for: - arc, mips, sparc Now SPARC64 is a wee bit special in that flush_tlb_range() is a no-op and it flushes the TLBs using arch_{enter,leave}_lazy_mmu_mode() inside the PTL. It still needs to guarantee the PTL unlock happens _after_ the invalidate completes. Vineet, Ralf and Dave could you guys please have a look? Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rik van Riel <riel@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Documentation/locking/atomic: Add documents for new atomic_t APIsPeter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Since we've vastly expanded the atomic_t interface in recent years the existing documentation is woefully out of date and people seem to get confused a bit. Start a new document to hopefully better explain the current state of affairs. The old atomic_ops.txt also covers bitmaps and a few more details so this is not a full replacement and we'll therefore keep that document around until such a time that we've managed to write more text to cover its entire. Also please, ReST people, go away. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()Marc Zyngier2017-08-10
| | | | | | | | | | | | | | | Use the new static_branch_enable_cpuslocked() function to switch the workaround static key on the CPU hotplug path. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170801080257.5056-5-marc.zyngier@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Provide hotplug context variantsMarc Zyngier2017-08-10
| | | | | | | | | | | | | | | | | | As using the normal static key API under the hotplug lock is pretty much impossible, let's provide a variant of some of them that require the hotplug lock to have already been taken. These function are only meant to be used in CPU hotplug callbacks. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170801080257.5056-4-marc.zyngier@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Split out code under the hotplug lockMarc Zyngier2017-08-10
| | | | | | | | | | | | | | | | | | In order to later introduce an "already locked" version of some of the static key funcions, let's split the code into the core stuff (the *_cpuslocked functions) and the usual helpers, which now take/release the hotplug lock and call into the _cpuslocked versions. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170801080257.5056-3-marc.zyngier@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Move CPU hotplug lockingMarc Zyngier2017-08-10
| | | | | | | | | | | | | | | | As we're about to rework the locking, let's move the taking and release of the CPU hotplug lock to locations that will make its reworking completely obvious. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170801080257.5056-2-marc.zyngier@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Add RELEASE barrier after text changesPeter Zijlstra2017-08-10
| | | | | | | | | | | | | | In the unlikely case text modification does not fully order things, add some extra ordering of our own to ensure we only enabled the fast path after all text is visible. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* cpuset: Make nr_cpusets privatePaolo Bonzini2017-08-10
| | | | | | | | | | | | | | | | | | Any use of key->enabled (that is static_key_enabled and static_key_count) outside jump_label_lock should handle its own serialization. In the case of cpusets_enabled_key, the key is always incremented/decremented under cpuset_mutex, and hence the same rule applies to nr_cpusets. The rule *is* respected currently, but the mutex is static so nr_cpusets should be static too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Zefan Li <lizefan@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1501601046-35683-4-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Do not use unserialized static_key_enabled()Paolo Bonzini2017-08-10
| | | | | | | | | | | | | | | | | | Any use of key->enabled (that is static_key_enabled and static_key_count) outside jump_label_lock should handle its own serialization. The only two that are not doing so are the UDP encapsulation static keys. Change them to use static_key_enable, which now correctly tests key->enabled under the jump label lock. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1501601046-35683-3-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: Fix concurrent static_key_enable/disable()Paolo Bonzini2017-08-10
| | | | | | | | | | | | | | | | | | | | | static_key_enable/disable are trying to cap the static key count to 0/1. However, their use of key->enabled is outside jump_label_lock so they do not really ensure that. Rewrite them to do a quick check for an already enabled (respectively, already disabled), and then recheck under the jump label lock. Unlike static_key_slow_inc/dec, a failed check under the jump label lock does not modify key->enabled. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1501601046-35683-2-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/rwsem-xadd: Add killable versions of rwsem_down_read_failed()Kirill Tkhai2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename rwsem_down_read_failed() in __rwsem_down_read_failed_common() and teach it to abort waiting in case of pending signals and killable state argument passed. Note, that we shouldn't wake anybody up in EINTR path, as: We check for (waiter.task) under spinlock before we go to out_nolock path. Current task wasn't able to be woken up, so there are a writer, owning the sem, or a writer, which is the first waiter. In the both cases we shouldn't wake anybody. If there is a writer, owning the sem, and we were the only waiter, remove RWSEM_WAITING_BIAS, as there are no waiters anymore. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.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: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Link: http://lkml.kernel.org/r/149789534632.9059.2901382369609922565.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/rwsem-spinlock: Add killable versions of __down_read()Kirill Tkhai2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename __down_read() in __down_read_common() and teach it to abort waiting in case of pending signals and killable state argument passed. Note, that we shouldn't wake anybody up in EINTR path, as: We check for signal_pending_state() after (!waiter.task) test and under spinlock. So, current task wasn't able to be woken up. It may be in two cases: a writer is owner of the sem, or a writer is a first waiter of the sem. If a writer is owner of the sem, no one else may work with it in parallel. It will wake somebody, when it call up_write() or downgrade_write(). If a writer is the first waiter, it will be woken up, when the last active reader releases the sem, and sem->count became 0. Also note, that set_current_state() may be moved down to schedule() (after !waiter.task check), as all assignments in this type of semaphore (including wake_up), occur under spinlock, so we can't miss anything. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.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: arnd@arndb.de Cc: avagin@virtuozzo.com Cc: davem@davemloft.net Cc: fenghua.yu@intel.com Cc: gorcunov@virtuozzo.com Cc: heiko.carstens@de.ibm.com Cc: hpa@zytor.com Cc: ink@jurassic.park.msu.ru Cc: mattst88@gmail.com Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Link: http://lkml.kernel.org/r/149789533283.9059.9829416940494747182.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/osq_lock: Fix osq_lock queue corruptionPrateek Sood2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix ordering of link creation between node->prev and prev->next in osq_lock(). A case in which the status of optimistic spin queue is CPU6->CPU2 in which CPU6 has acquired the lock. tail v ,-. <- ,-. |6| |2| `-' -> `-' At this point if CPU0 comes in to acquire osq_lock, it will update the tail count. CPU2 CPU0 ---------------------------------- tail v ,-. <- ,-. ,-. |6| |2| |0| `-' -> `-' `-' After tail count update if CPU2 starts to unqueue itself from optimistic spin queue, it will find an updated tail count with CPU0 and update CPU2 node->next to NULL in osq_wait_next(). unqueue-A tail v ,-. <- ,-. ,-. |6| |2| |0| `-' `-' `-' unqueue-B ->tail != curr && !node->next If reordering of following stores happen then prev->next where prev being CPU2 would be updated to point to CPU0 node: tail v ,-. <- ,-. ,-. |6| |2| |0| `-' `-' -> `-' osq_wait_next() node->next <- 0 xchg(node->next, NULL) tail v ,-. <- ,-. ,-. |6| |2| |0| `-' `-' `-' unqueue-C At this point if next instruction WRITE_ONCE(next->prev, prev); in CPU2 path is committed before the update of CPU0 node->prev = prev then CPU0 node->prev will point to CPU6 node. tail v----------. v ,-. <- ,-. ,-. |6| |2| |0| `-' `-' `-' `----------^ At this point if CPU0 path's node->prev = prev is committed resulting in change of CPU0 prev back to CPU2 node. CPU2 node->next is NULL currently, tail v ,-. <- ,-. <- ,-. |6| |2| |0| `-' `-' `-' `----------^ so if CPU0 gets into unqueue path of osq_lock it will keep spinning in infinite loop as condition prev->next == node will never be true. Signed-off-by: Prateek Sood <prsood@codeaurora.org> [ Added pictures, rewrote comments. ] 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: sramana@codeaurora.org Link: http://lkml.kernel.org/r/1500040076-27626-1-git-send-email-prsood@codeaurora.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking/atomic: Fix atomic_set_release() for 'funny' architecturesPeter Zijlstra2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Those architectures that have a special atomic_set implementation also need a special atomic_set_release(), because for the very same reason WRITE_ONCE() is broken for them, smp_store_release() is too. The vast majority is architectures that have spinlock hash based atomic implementation except hexagon which seems to have a hardware 'feature'. The spinlock based atomics should be SC, that is, none of them appear to place extra barriers in atomic_cmpxchg() or any of the other SC atomic primitives and therefore seem to rely on their spinlock implementation being SC (I did not fully validate all that). Therefore, the normal atomic_set() is SC and can be used at atomic_set_release(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile] Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: davem@davemloft.net Cc: james.hogan@imgtec.com Cc: jejb@parisc-linux.org Cc: rkuo@codeaurora.org Cc: vgupta@synopsys.com Link: http://lkml.kernel.org/r/20170609110506.yod47flaav3wgoj5@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/wait: Remove the lockless swait_active() check in swake_up*()Boqun Feng2017-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Steven Rostedt reported a potential race in RCU core because of swake_up(): CPU0 CPU1 ---- ---- __call_rcu_core() { spin_lock(rnp_root) need_wake = __rcu_start_gp() { rcu_start_gp_advanced() { gp_flags = FLAG_INIT } } rcu_gp_kthread() { swait_event_interruptible(wq, gp_flags & FLAG_INIT) { spin_lock(q->lock) *fetch wq->task_list here! * list_add(wq->task_list, q->task_list) spin_unlock(q->lock); *fetch old value of gp_flags here * spin_unlock(rnp_root) rcu_gp_kthread_wake() { swake_up(wq) { swait_active(wq) { list_empty(wq->task_list) } * return false * if (condition) * false * schedule(); In this case, a wakeup is missed, which could cause the rcu_gp_kthread waits for a long time. The reason of this is that we do a lockless swait_active() check in swake_up(). To fix this, we can either 1) add a smp_mb() in swake_up() before swait_active() to provide the proper order or 2) simply remove the swait_active() in swake_up(). The solution 2 not only fixes this problem but also keeps the swait and wait API as close as possible, as wake_up() doesn't provide a full barrier and doesn't do a lockless check of the wait queue either. Moreover, there are users already using swait_active() to do their quick checks for the wait queues, so it make less sense that swake_up() and swake_up_all() do this on their own. This patch then removes the lockless swait_active() check in swake_up() and swake_up_all(). Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Krister Johansen <kjlx@templeofstupid.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170615041828.zk3a3sfyudm5p6nl@tardis Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar2017-08-10
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge tag 'pinctrl-v4.13-2' of ↵Linus Torvalds2017-08-09
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control fixes from Linus Walleij: "These are the pin control fixes I have gathered since the return from my vacation. They boiled in -next a while so let's get them in. Apart from the documentation build it is purely driver fixes. Which is nice. The Intel fixes seem kind of important. - Fix the documentation build as the docs were moved - Correct the UART pin list on the Intel Merrifield - Fix pin assignment and number of pins on the Marvell Armada 37xx pin controller - Cover the Setzer models in the Chromebook DMI quirk in the Intel cheryview driver so they start working - Add the missing "sim" function to the sunxi driver - Fix USB pin definitions on Uniphier Pro4 - Smatch fix for invalid reference in the zx pin control driver" * tag 'pinctrl-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: generic: update references to Documentation/pinctrl.txt pinctrl: intel: merrifield: Correct UART pin lists pinctrl: armada-37xx: Fix number of pin in south bridge pinctrl: armada-37xx: Fix the pin 23 on south bridge pinctrl: cherryview: Add Setzer models to the Chromebook DMI quirk pinctrl: sunxi: add a missing function of A10/A20 pinctrl driver pinctrl: uniphier: fix USB3 pin assignment for Pro4 pinctrl: zte: fix dereference of 'data' in zx_set_mux()
| | * pinctrl: generic: update references to Documentation/pinctrl.txtLudovic Desroches2017-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | Update deprecated references to Documentation/pinctrl.txt since it has been moved to Documentation/driver-api/pinctl.rst. Signed-off-by: Ludovic Desroches <ludovic.desroches@o2linux.fr> Fixes: 5a9b73832e9e ("pinctrl.txt: move it to the driver-api book") Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: intel: merrifield: Correct UART pin listsAndy Shevchenko2017-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UART pin lists consist GPIO numbers which is simply wrong. Replace it by pin numbers. Fixes: 4e80c8f50574 ("pinctrl: intel: Add Intel Merrifield pin controller support") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: armada-37xx: Fix number of pin in south bridgeGregory CLEMENT2017-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On the south bridge we have pin from to 29, so it gives 30 pins (and not 29). Without this patch the kernel complain with the following traces: cat /sys/kernel/debug/pinctrl/d0018800.pinctrl/pingroups [ 154.530205] armada-37xx-pinctrl d0018800.pinctrl: failed to get pin(29) name [ 154.537567] ------------[ cut here ]------------ [ 154.542348] WARNING: CPU: 1 PID: 1347 at /home/gclement/open/kernel/marvell-mainline-linux/drivers/pinctrl/core.c:1610 pinctrl_groups_show+0x15c/0x1a0 [ 154.555918] Modules linked in: [ 154.558890] CPU: 1 PID: 1347 Comm: cat Tainted: G W 4.13.0-rc1-00001-g19e1b9fa219d #525 [ 154.568316] Hardware name: Marvell Armada 3720 Development Board DB-88F3720-DDR3 (DT) [ 154.576311] task: ffff80001d32d100 task.stack: ffff80001bdc0000 [ 154.583048] PC is at pinctrl_groups_show+0x15c/0x1a0 [ 154.587816] LR is at pinctrl_groups_show+0x148/0x1a0 [ 154.592847] pc : [<ffff0000083e3adc>] lr : [<ffff0000083e3ac8>] pstate: 00000145 [ 154.600840] sp : ffff80001bdc3c80 [ 154.604255] x29: ffff80001bdc3c80 x28: 00000000f7750000 [ 154.609825] x27: ffff80001d05d198 x26: 0000000000000009 [ 154.615224] x25: ffff0000089ead20 x24: 0000000000000002 [ 154.620705] x23: ffff000008c8e1d0 x22: ffff80001be55700 [ 154.626187] x21: ffff80001d05d100 x20: 0000000000000005 [ 154.631667] x19: 0000000000000006 x18: 0000000000000010 [ 154.637238] x17: 0000000000000000 x16: ffff0000081fc4b8 [ 154.642726] x15: 0000000000000006 x14: ffff0000899e537f [ 154.648214] x13: ffff0000099e538d x12: 206f742064656c69 [ 154.653613] x11: 6166203a6c727463 x10: 0000000005f5e0ff [ 154.659094] x9 : ffff80001bdc38c0 x8 : 286e697020746567 [ 154.664576] x7 : ffff000008551870 x6 : 000000000000011b [ 154.670146] x5 : 0000000000000000 x4 : 0000000000000000 [ 154.675544] x3 : 0000000000000000 x2 : 0000000000000000 [ 154.681025] x1 : ffff000008c8e1d0 x0 : ffff80001be55700 [ 154.686507] Call trace: [ 154.688668] Exception stack(0xffff80001bdc3ab0 to 0xffff80001bdc3be0) [ 154.695224] 3aa0: 0000000000000006 0001000000000000 [ 154.703310] 3ac0: ffff80001bdc3c80 ffff0000083e3adc ffff80001bdc3bb0 00000000ffffffd8 [ 154.711304] 3ae0: 4554535953425553 6f6674616c703d4d 4349564544006d72 6674616c702b3d45 [ 154.719478] 3b00: 313030643a6d726f 6e69702e30303838 ffff80006c727463 ffff0000089635d8 [ 154.727562] 3b20: ffff80001d1ca0cb ffff000008af0fa4 ffff80001bdc3b40 ffff000008c8e1dc [ 154.735648] 3b40: ffff80001bdc3bc0 ffff000008223174 ffff80001be55700 ffff000008c8e1d0 [ 154.743731] 3b60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 154.752354] 3b80: 000000000000011b ffff000008551870 286e697020746567 ffff80001bdc38c0 [ 154.760446] 3ba0: 0000000005f5e0ff 6166203a6c727463 206f742064656c69 ffff0000099e538d [ 154.767910] 3bc0: ffff0000899e537f 0000000000000006 ffff0000081fc4b8 0000000000000000 [ 154.776085] [<ffff0000083e3adc>] pinctrl_groups_show+0x15c/0x1a0 [ 154.782823] [<ffff000008222abc>] seq_read+0x184/0x460 [ 154.787505] [<ffff000008344120>] full_proxy_read+0x60/0xa8 [ 154.793431] [<ffff0000081f9bec>] __vfs_read+0x1c/0x110 [ 154.799001] [<ffff0000081faff4>] vfs_read+0x84/0x140 [ 154.803860] [<ffff0000081fc4fc>] SyS_read+0x44/0xa0 [ 154.808983] [<ffff000008082f30>] el0_svc_naked+0x24/0x28 [ 154.814459] ---[ end trace 4cbb00a92d616b95 ]--- Cc: stable@vger.kernel.org Fixes: 87466ccd9401 ("pinctrl: armada-37xx: Add pin controller support for Armada 37xx") Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: armada-37xx: Fix the pin 23 on south bridgeGregory CLEMENT2017-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pin 23 on South bridge does not belong to the rgmii group. It belongs to a separate group which can have 3 functions. Due to this the fix also have to update the way the functions are managed. Until now each groups used NB_FUNCS(which was 2) functions. For the mpp23, 3 functions are available but it is the only group which needs it, so on the loop involving NB_FUNCS an extra test was added to handle only the functions added. The bug was visible with the merge of the commit 07d065abf93d "arm64: dts: marvell: armada-3720-db: Add vqmmc regulator for SD slot", the gpio regulator used the gpio 23, due to this the whole rgmii group was setup to gpio which broke the Ethernet support on the Armada 3720 DB board. Thanks to this patch, the UHS SD cards (which need the vqmmc) _and_ the Ethernet work again. Cc: stable@vger.kernel.org Fixes: 87466ccd9401 ("pinctrl: armada-37xx: Add pin controller support for Armada 37xx") Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: cherryview: Add Setzer models to the Chromebook DMI quirkAndy Shevchenko2017-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add one more model to the Chromebook DMI quirk to make it working again. Link: https://bugzilla.kernel.org/show_bug.cgi?id=194945 Fixes: 2a8209fa6823 ("pinctrl: cherryview: Extend the Chromebook DMI quirk to Intel_Strago systems") Reported-by: mail@abhishek.geek.nz Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: sunxi: add a missing function of A10/A20 pinctrl driverIcenowy Zheng2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PH16 pin has a function with mux id 0x5, which is the DET pin of the "sim" (smart card reader) IP block. This function is missing in old versions of A10/A20 SoCs' datasheets and user manuals, so it's also missing in the old drivers. The newest A10 Datasheet V1.70 and A20 Datasheet V1.41 contain this pin function, and it's discovered during implementing R40 pinctrl driver. Add it to the driver. As we now merged A20 pinctrl driver to the A10 one, we need to only fix the A10 driver now. Fixes: f2821b1ca3a2 ("pinctrl: sunxi: Move Allwinner A10 pinctrl driver to a driver of its own") Signed-off-by: Icenowy Zheng <icenowy@aosc.io> Reviewed-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: uniphier: fix USB3 pin assignment for Pro4Kunihiko Hayashi2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to pinctrl assignment for Pro4, each definition of USB#2 and USB#3 are as follows. 184: USB2VBUS 185: USB2OD 186: USB2ID 187: USB3VBUS 188: USB3OD USB#2 has an additional pin "USB2ID", but the chip doesn't use this pin while in host-mode. Considering this pin, the pin definitions for USB#3 should be {187, 188}. Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| | * pinctrl: zte: fix dereference of 'data' in zx_set_mux()Shawn Guo2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It fixes the following Smatch complaint: drivers/pinctrl/zte/pinctrl-zx.c:76 zx_set_mux() warn: variable dereferenced before check 'data' (see line 67) Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: cbff0c4d27f4 ("pinctrl: add ZTE ZX pinctrl driver support") Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| * | futex: Remove unnecessary warning from get_futex_keyMel Gorman2017-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 65d8fc777f6d ("futex: Remove requirement for lock_page() in get_futex_key()") removed an unnecessary lock_page() with the side-effect that page->mapping needed to be treated very carefully. Two defensive warnings were added in case any assumption was missed and the first warning assumed a correct application would not alter a mapping backing a futex key. Since merging, it has not triggered for any unexpected case but Mark Rutland reported the following bug triggering due to the first warning. kernel BUG at kernel/futex.c:679! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3 Hardware name: linux,dummy-virt (DT) task: ffff80001e271780 task.stack: ffff000010908000 PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679 LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679 pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145 The fact that it's a bug instead of a warning was due to an unrelated arm64 problem, but the warning itself triggered because the underlying mapping changed. This is an application issue but from a kernel perspective it's a recoverable situation and the warning is unnecessary so this patch removes the warning. The warning may potentially be triggered with the following test program from Mark although it may be necessary to adjust NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the system. #include <linux/futex.h> #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <sys/syscall.h> #include <sys/time.h> #include <unistd.h> #define NR_FUTEX_THREADS 16 pthread_t threads[NR_FUTEX_THREADS]; void *mem; #define MEM_PROT (PROT_READ | PROT_WRITE) #define MEM_SIZE 65536 static int futex_wrapper(int *uaddr, int op, int val, const struct timespec *timeout, int *uaddr2, int val3) { syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3); } void *poll_futex(void *unused) { for (;;) { futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1); } } int main(int argc, char *argv[]) { int i; mem = mmap(NULL, MEM_SIZE, MEM_PROT, MAP_SHARED | MAP_ANONYMOUS, -1, 0); printf("Mapping @ %p\n", mem); printf("Creating futex threads...\n"); for (i = 0; i < NR_FUTEX_THREADS; i++) pthread_create(&threads[i], NULL, poll_futex, NULL); printf("Flipping mapping...\n"); for (;;) { mmap(mem, MEM_SIZE, MEM_PROT, MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0); } return 0; } Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org # 4.7+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | Merge branch 'i2c/for-current' of ↵Linus Torvalds2017-08-09
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fixes from Wolfram Sang: "The main thing is to allow empty id_tables for ACPI to make some drivers get probed again. It looks a bit bigger than usual because it needs some internal renaming, too. Other than that, there is a fix for broken DSTDs, a super simple enablement for ARM MPS, and two documentation fixes which I'd like to see in v4.13 already" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: rephrase explanation of I2C_CLASS_DEPRECATED i2c: allow i2c-versatile for ARM MPS platforms i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHz i2c: designware: Print clock freq on invalid clock freq error i2c: core: Allow empty id_table in ACPI case as well i2c: mux: pinctrl: mention correct module name in Kconfig help text
| | * | i2c: rephrase explanation of I2C_CLASS_DEPRECATEDWolfram Sang2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | Hopefully making clear that it is not needed for new drivers. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: allow i2c-versatile for ARM MPS platformsRussell King2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow i2c-versatile to be enabled for ARM MPS platforms. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | Merge branch 'i2c-mux/for-current' of https://github.com/peda-r/i2c-mux into ↵Wolfram Sang2017-07-31
| | |\ \ | | | | | | | | | | | | | | | i2c/for-current
| | | * | i2c: mux: pinctrl: mention correct module name in Kconfig help textChris Gorman2017-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kconfig says the resulting module is pinctrl-i2cmux, but the module when built is i2c-mux-pinctrl. Fixes: ae58d1e40698 ("i2c: Add generic I2C multiplexer using pinctrl API") Signed-off-by: Chris Gorman <chrisjohgorman@gmail.com> Signed-off-by: Peter Rosin <peda@axentia.se>
| | * | | i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHzHans de Goede2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At least the Acer Iconia Tab8 / aka W1-810 uses 1MiHz instead of 1MHz for one of its busses, fix this up to 1MHz instead of failing the probe of that bus. This fixes the accelerometer on the Acer Iconia Tab8 not working. Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | | i2c: designware: Print clock freq on invalid clock freq errorHans de Goede2017-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we refuse to probe due to an invalid clock frequency, log the frequency which is causing this error. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | | i2c: core: Allow empty id_table in ACPI case as wellAndy Shevchenko2017-07-31
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For now empty ID table is not allowed with ACPI and prevents driver to be probed. Add a check to allow empty ID table. This introduces a helper i2c_acpi_match_device(). Note, we rename some static function in i2c-core-acpi.c to distinguish with public API. Fixes: da10c06a044b ("i2c: Make I2C ID tables non-mandatory for DT'ed devices") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Rajmohan Mani <rajmohan.mani@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> [wsa: needed to get some drivers probed again] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | | Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2017-08-09
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "Three patches that should go into this release. Two of them are from Paolo and fix up some corner cases with BFQ, and the last patch is from Ming and fixes up a potential usage count imbalance regression due to the recent NOWAIT work" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed block, bfq: consider also in_service_entity to state whether an entity is active block, bfq: reset in_service_entity if it becomes idle
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-18 11:47:13 -0400