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* Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2015-09-03139-3585/+2425
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking and atomic updates from Ingo Molnar: "Main changes in this cycle are: - Extend atomic primitives with coherent logic op primitives (atomic_{or,and,xor}()) and deprecate the old partial APIs (atomic_{set,clear}_mask()) The old ops were incoherent with incompatible signatures across architectures and with incomplete support. Now every architecture supports the primitives consistently (by Peter Zijlstra) - Generic support for 'relaxed atomics': - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return() - atomic_read_acquire() - atomic_set_release() This came out of porting qwrlock code to arm64 (by Will Deacon) - Clean up the fragile static_key APIs that were causing repeat bugs, by introducing a new one: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. To be able to know the 'type' of the static key we encode it in the jump entry (by Peter Zijlstra) - Static key self-tests (by Jason Baron) - qrwlock optimizations (by Waiman Long) - small futex enhancements (by Davidlohr Bueso) - ... and misc other changes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits) jump_label/x86: Work around asm build bug on older/backported GCCs locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics locking/qrwlock: Implement queue_write_unlock() using smp_store_release() locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t' locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic locking/static_keys: Make verify_keys() static jump label, locking/static_keys: Update docs locking/static_keys: Provide a selftest jump_label: Provide a self-test s390/uaccess, locking/static_keys: employ static_branch_likely() x86, tsc, locking/static_keys: Employ static_branch_likely() locking/static_keys: Add selftest locking/static_keys: Add a new static_key interface locking/static_keys: Rework update logic locking/static_keys: Add static_key_{en,dis}able() helpers ...
| * jump_label/x86: Work around asm build bug on older/backported GCCsPeter Zijlstra2015-08-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Boris reported that gcc version 4.4.4 20100503 (Red Hat 4.4.4-2) fails to build linux-next kernels that have this fresh commit via the locking tree: 11276d5306b8 ("locking/static_keys: Add a new static_key interface") The problem appears to be that even though @key and @branch are compile time constants, it doesn't see the following expression as an immediate value: &((char *)key)[branch] More recent GCCs don't appear to have this problem. In particular, Red Hat backported the 'asm goto' feature into 4.4, 'normal' 4.4 compilers will not have this feature and thus not run into this asm. The workaround is to supply both values to the asm as immediates and do the addition in asm. Suggested-by: H. Peter Anvin <hpa@zytor.com> Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operationsWill Deacon2015-08-122-60/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By defining our SMP atomics in terms of relaxed operations, we gain a small reduction in code size and have acquire/release/fence variants generated automatically by the core code. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-9-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.hWill Deacon2015-08-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Including an asm/ header directly is best avoided, so use linux/atomic.h instead of asm/cmpxchg.h in linux/llist.h. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-8-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking/qrwlock: Make use of _{acquire|release|relaxed}() atomicsWill Deacon2015-08-122-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The qrwlock implementation is slightly heavy in its use of memory barriers, mainly through the use of _cmpxchg() and _return() atomics, which imply full barrier semantics. This patch modifies the qrwlock code to use the more relaxed atomic routines so that we can reduce the unnecessary barrier overhead on weakly-ordered architectures. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-7-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking/qrwlock: Implement queue_write_unlock() using smp_store_release()Will Deacon2015-08-122-18/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the following commit: 536fa402221f ("compiler: Allow 1- and 2-byte smp_load_acquire() and smp_store_release()") smp_store_release() supports byte accesses, so use that in writer unlock and remove the conditional macro override. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <Waiman.Long@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-6-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definitionWill Deacon2015-08-121-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cmpxchg64_relaxed() is now defined by linux/atomic.h, so we can remove our local definition from the lockref code. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-5-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking, asm-generic: Add _{relaxed|acquire|release}() variants for ↵Will Deacon2015-08-121-27/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'atomic_long_t' This patch adds 'atomic_long_t' wrappers for the new relaxed atomic operations. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking, asm-generic: Rework atomic-long.h to avoid bulk code duplicationWill Deacon2015-08-121-149/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can use some (admittedly ugly) macros to generate the 32-bit and 64-bit based atomic_long implementations from the same code. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic ↵Will Deacon2015-08-121-0/+323
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | operations Whilst porting the generic qrwlock code over to arm64, it became apparent that any portable locking code needs finer-grained control of the memory-ordering guarantees provided by our atomic routines. In particular: xchg, cmpxchg, {add,sub}_return are often used in situations where full barrier semantics (currently the only option available) are not required. For example, when a reader increments a reader count to obtain a lock, checking the old value to see if a writer was present, only acquire semantics are strictly needed. This patch introduces three new ordering semantics for these operations: - *_relaxed: No ordering guarantees. This is similar to what we have already for the non-return atomics (e.g. atomic_add). - *_acquire: ACQUIRE semantics, similar to smp_load_acquire. - *_release: RELEASE semantics, similar to smp_store_release. In memory-ordering speak, this means that the acquire/release semantics are RCpc as opposed to RCsc. Consequently a RELEASE followed by an ACQUIRE does not imply a full barrier, as already documented in memory-barriers.txt. Currently, all the new macros are conditionally mapped to the full-mb variants, however if the *_relaxed version is provided by the architecture, then the acquire/release variants are constructed by supplementing the relaxed routine with an explicit barrier. Signed-off-by: Will Deacon <will.deacon@arm.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: Waiman.Long@hp.com Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1438880084-18856-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * locking, compiler.h: Cast away attributes in the WRITE_ONCE() magicChristian Borntraeger2015-08-121-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel build bot showed a new warning triggered by commit: 76695af20c01 ("locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire()") because Sparse does not like WRITE_ONCE() accessing elements from the (sparse) RCU address space: fs/afs/inode.c:448:9: sparse: incorrect type in initializer (different address spaces) fs/afs/inode.c:448:9: expected struct afs_permits *__val fs/afs/inode.c:448:9: got void [noderef] <asn:4>*<noident> Solution is to force cast away the sparse attributes for the initializer of the union in WRITE_ONCE(). (And as this now gets too long, also split the macro into multiple lines.) Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrey Konovalov <andreyknvl@google.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> Link: http://lkml.kernel.org/r/1438674948-38310-2-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge branch 'locking/arch-atomic' into locking/core, because it's ready for ↵Ingo Molnar2015-08-1265-1015/+841
| |\ | | | | | | | | | | | | | | | upstream Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * atomic: Add simple atomic_t testsPeter Zijlstra2015-07-271-21/+47
| | | | | | | | | | | | | | | | | | | | | | | | Add a few atomic_t tests, gets some compile coverage for the new operations. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * atomic: Replace atomic_{set,clear}_mask() usagePeter Zijlstra2015-07-2714-97/+97
| | | | | | | | | | | | | | | | | | | | | | | | Replace the deprecated atomic_{set,clear}_mask() usage with the now ubiquous atomic_{or,andnot}() functions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * atomic: Collapse all atomic_{set,clear}_mask definitionsPeter Zijlstra2015-07-2716-174/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the now generic definitions of atomic_{set,clear}_mask() into linux/atomic.h to avoid endless and pointless repetition. Also, provide an atomic_andnot() wrapper for those few archs that can implement that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * atomic: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-2729-68/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * tile: Provide atomic_{or,xor,and}Chris Metcalf2015-07-274-0/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. For tilegx, these are relatively straightforward; the architecture provides atomic "or" and "and", both 32-bit and 64-bit. To support xor we provide a loop using "cmpexch". For the older 32-bit tilepro architecture, we have to extend the set of low-level assembly routines to include 32-bit "and", as well as all three 64-bit routines. Somewhat confusingly, some 32-bit versions are already used by the bitops inlines, with parameter types appropriate for bitops, so we have to do a bit of casting to match "int" to "unsigned long". Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1436474297-32187-1-git-send-email-cmetcalf@ezchip.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * h8300: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-95/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and} These will replace the atomic_{set,clear}_mask functions that are available on some archs. Also rework the atomic implementation in terms of CPP macros to avoid the typical repetition -- I seem to have missed this arch the last time around when I did that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * frv: Rewrite atomic implementationPeter Zijlstra2015-07-279-355/+259
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly complete rewrite of the FRV atomic implementation, instead of using assembly files, use inline assembler. The out-of-line CONFIG option makes a bit of a mess of things, but a little CPP trickery gets that done too. FRV already had the atomic logic ops but under a non standard name, the reimplementation provides the generic names and provides the intermediate form required for the bitops implementation. The slightly inconsistent __atomic32_fetch_##op naming is because __atomic_fetch_##op conlicts with GCC builtin functions. The 64bit atomic ops use the inline assembly %Ln construct to access the low word register (r+1), afaik this construct was not previously used in the kernel and is completely undocumented, but I found it in the FRV GCC code and it seems to work. FRV had a non-standard definition of atomic_{clear,set}_mask() which would work types other than atomic_t, the one user relying on that (arch/frv/kernel/dma.c) got converted to use the new intermediate form. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * x86: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-273-8/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * s390: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-14/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * xtensa: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-69/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * sparc: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-275-3/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * sh: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-274-85/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * powerpc: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * parisc: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * mn10300: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-47/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * mips: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * metag: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-272-42/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * m68k: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * m32r: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-34/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * ia64: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * hexagon: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * blackfin: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-273-25/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. TODO: use inline asm or at least asm macros to collapse the lot. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * avr32: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * arm64: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * arm: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * arc: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * alpha: Provide atomic_{or,xor,and}Peter Zijlstra2015-07-271-15/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement atomic logic ops -- atomic_{or,xor,and}. These will replace the atomic_{set,clear}_mask functions that are available on some archs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * atomic: Prepare generic atomic implementation for logic opsPeter Zijlstra2015-07-271-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | Clean up the #ifdef guards a bit to prepare for architectures to supply their own logic ops. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | locking/static_keys: Make verify_keys() statickbuild test robot2015-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150803184748.GA80634@lkp-ib04 Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | jump label, locking/static_keys: Update docsJason Baron2015-08-032-68/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: bp@alien8.de Cc: davem@davemloft.net Cc: ddaney@caviumnetworks.com Cc: heiko.carstens@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: liuj97@gmail.com Cc: luto@amacapital.net Cc: michael@ellerman.id.au Cc: rabin@rab.in Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: vbabka@suse.cz Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/6b50f2f6423a2244f37f4b1d2d6c211b9dcdf4f8.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | locking/static_keys: Provide a selftestIngo Molnar2015-08-038-253/+253
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'jump label' self-test is in reality testing static keys - rename things accordingly. Also prettify the code in various places while at it. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: bp@alien8.de Cc: davem@davemloft.net Cc: ddaney@caviumnetworks.com Cc: heiko.carstens@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: liuj97@gmail.com Cc: luto@amacapital.net Cc: michael@ellerman.id.au Cc: rabin@rab.in Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: vbabka@suse.cz Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | jump_label: Provide a self-testJason Baron2015-08-037-0/+329
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: bp@alien8.de Cc: davem@davemloft.net Cc: ddaney@caviumnetworks.com Cc: heiko.carstens@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: liuj97@gmail.com Cc: luto@amacapital.net Cc: michael@ellerman.id.au Cc: rabin@rab.in Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: shuahkh@osg.samsung.com Cc: vbabka@suse.cz Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | s390/uaccess, locking/static_keys: employ static_branch_likely()Heiko Carstens2015-08-031-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the new static_branch_likely() primitive to make sure that the most likely case is executed without taking an unconditional branch. This wasn't possible with the old jump label primitives. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150729064600.GB3953@osiris Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86, tsc, locking/static_keys: Employ static_branch_likely()Peter Zijlstra2015-08-031-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because of the static_key restrictions we had to take an unconditional jump for the most likely case, causing $I bloat. Rewrite to use the new primitives. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | locking/static_keys: Add selftestPeter Zijlstra2015-08-032-1/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a little selftest that validates all combinations. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | locking/static_keys: Add a new static_key interfacePeter Zijlstra2015-08-039-44/+298
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are various problems and short-comings with the current static_key interface: - static_key_{true,false}() read like a branch depending on the key value, instead of the actual likely/unlikely branch depending on init value. - static_key_{true,false}() are, as stated above, tied to the static_key init values STATIC_KEY_INIT_{TRUE,FALSE}. - we're limited to the 2 (out of 4) possible options that compile to a default NOP because that's what our arch_static_branch() assembly emits. So provide a new static_key interface: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); Which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. This means adding a second arch_static_branch_jump() assembly helper which emits a JMP per default. In order to determine the right instruction for the right state, encode the branch type in the LSB of jump_entry::key. This is the final step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") ... but it also allows new static key combinations that will give us performance enhancements in the subsequent patches. Tested-by: Rabin Vincent <rabin@rab.in> # arm Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> # ppc Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | locking/static_keys: Rework update logicPeter Zijlstra2015-08-031-50/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of spreading the branch_default logic all over the place, concentrate it into the one jump_label_type() function. This does mean we need to actually increment/decrement the enabled count _before_ calling the update path, otherwise jump_label_type() will not see the right state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | locking/static_keys: Add static_key_{en,dis}able() helpersPeter Zijlstra2015-08-032-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two helpers to make it easier to treat the refcount as boolean. Suggested-by: Jason Baron <jasonbaron0@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>