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2016-11-11s390/atomic: refactor atomic primitivesMartin Schwidefsky1-168/+39
Rework atomic.h to make the low level functions avaible for use in other headers without using atomic_t, e.g. in bitops.h. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-16locking/atomic: Remove linux/atomic.h:atomic_fetch_or()Peter Zijlstra1-2/+0
Since all architectures have this implemented now natively, remove this dead code. 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-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16locking/atomic, arch/s390: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()Peter Zijlstra1-10/+32
Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> 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-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-14s390/barrier: remove unnecessary serialization in atomics and bitopsMartin Schwidefsky1-2/+0
The principles of operation states reads are in order, writes are in order, writes can be reordered after reads, but no reads can be reordered after writes. The atomic and bitops variantes for z196 use the interlocked-access facility instructions with a memory barrier before and after the instruction. Because of the memory ordering the first barrier is unnecessary and can be removed. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-27atomic: Collapse all atomic_{set,clear}_mask definitionsPeter Zijlstra1-10/+0
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>
2015-07-27atomic: Provide atomic_{or,xor,and}Peter Zijlstra1-2/+0
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>
2015-07-27s390: Provide atomic_{or,xor,and}Peter Zijlstra1-14/+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>
2015-03-25s390: remove 31 bit supportHeiko Carstens1-95/+0
Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-18arch,s390: Convert smp_mb__*()Peter Zijlstra1-5/+0
As per the existing implementation; implement the new one using smp_mb(). AFAICT the s390 compare-and-swap does imply a barrier, however there are some immediate ops that seem to be singly-copy atomic and do not imply a barrier. One such is the "ni" op (which would be and-immediate) which is used for the constant clear_bit implementation. Therefore s390 needs full barriers for the {before,after} atomic ops. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-kme5dz5hcobpnufnnkh1ech2@git.kernel.org Cc: Chen Gang <gang.chen@asianux.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux390@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-01s390/bitops,atomic: add missing memory barriersHeiko Carstens1-28/+42
When reworking the bitops and atomic ops I missed that those instructions that got atomic behaviour only perform a "specific-operand-serialization" instead of a full "serialization". The compare-and-swap instruction used before performs a full serialization before and after the instruction is executed, which means it has full memory barrier semantics. In order to give the new bitops and atomic ops functions also full memory barrier semantics add a "bcr 14,0" before and after each of those new instructions which performs full serialization as well. This restores memory barrier semantics for bitops and atomic ops functions which return values, like e.g. atomic_add_return(), but not for functions which do not return a value, like e.g. atomic_add(). This is consistent to other architectures and what common code requires. Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/atomic: use 'unsigned int' instead of 'unsigned long' for atomic_*_mask()Chen Gang1-2/+2
The type of 'v->counter' is always 'int', and related inline assembly code also process 'int', so use 'unsigned int' instead of 'unsigned long' for the 'mask'. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/atomic: various small cleanupsHeiko Carstens1-18/+24
- add a typecheck to the defines to make sure they operate on an atomic_t - simplify inline assembly constraints - keep variable names common between functions Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/atomic: optimize atomic_add() for constant valuesHeiko Carstens1-8/+40
If the interlocked-access facility 1 is available we can use the asi and agsi instructions for interlocked updates if the to be added value is a contanst and small (in the range of -128..127). asi and agsi do not not return the old or new value, therefore these instructions can only be used for atomic_(add|sub|inc|dec)[64]. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/atomic: make use of interlocked-access facility 1 instructionsHeiko Carstens1-12/+65
Same as for bitops: make use of the interlocked-access facility 1 instructions which allow to atomically update storage locations without a compare-and-swap loop. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/atomic: implement atomic_sub_return() with atomic_add_return()Heiko Carstens1-21/+2
Get rid of the own atomic_sub_return() implementation. Otherwise we can't make use of the interlocked-access facility 1 instructions for atomic_sub_return(), since there is no "load and subtract" instruction available. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-20s390/comments: unify copyright messages and remove file namesHeiko Carstens1-4/+4
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-03-28Disintegrate asm/system.h for S390David Howells1-1/+1
Disintegrate asm/system.h for S390. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-s390@vger.kernel.org
2011-07-26atomic: cleanup asm-generic atomic*.h inclusionArun Sharma1-2/+0
After changing all consumers of atomics to include <linux/atomic.h>, we ran into some compile time errors due to this dependency chain: linux/atomic.h -> asm/atomic.h -> asm-generic/atomic-long.h where atomic-long.h could use funcs defined later in linux/atomic.h without a prototype. This patches moves the code that includes asm-generic/atomic*.h to linux/atomic.h. Archs that need <asm-generic/atomic64.h> need to select CONFIG_GENERIC_ATOMIC64 from now on (some of them used to include it unconditionally). Compile tested on i386 and x86_64 with allnoconfig. Signed-off-by: Arun Sharma <asharma@fb.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26atomic: move atomic_add_unless to generic codeArun Sharma1-2/+2
This is in preparation for more generic atomic primitives based on __atomic_add_unless. Signed-off-by: Arun Sharma <asharma@fb.com> Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma1-1/+0
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-31Fix common misspellingsLucas De Marchi1-1/+1
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-02-17[S390] atomic: use inline asmHeiko Carstens1-4/+18
Use inline assemblies for atomic_read/set(). This way there shouldn't be any questions or subtle volatile semantics left. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-02-17[S390] atomic: use ACCESS_ONCE() for atomic_read()Heiko Carstens1-6/+2
Let's make atomic_read() and atomic_set() behave like on all/most other architectures. Generated code is identical with gcc 4.5.2. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-26[S390] atomic: implement atomic64_dec_if_positiveHeiko Carstens1-0/+19
Implement atomic64_dec_if_positive and add missing system.h header include. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] use inline assembly contraints available with gcc 3.3.3Martin Schwidefsky1-75/+11
Drop support to compile the kernel with gcc versions older than 3.3.3. This allows us to use the "Q" inline assembly contraint on some more inline assemblies without duplicating a lot of complex code (e.g. __xchg and __cmpxchg). The distinction for older gcc versions can be removed which saves a few lines and simplifies the code. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] Improve code generated by atomic operations.Martin Schwidefsky1-4/+4
Git commit ea435467500612636f8f4fb639ff6e76b2496e4b changed the definition of atomic_t and atomic64_t for s390 by adding the volatile modifier to the counter field. This has an unfortunate side effect with newer versions of the gcc. The typeof operator now picks up the volatile modifier from the expression. This causes the compiler to think that it has to store the two temporary variable old_val and new_val in the __CS_LOOP for the different atomic operations to the stack as the variables are now volatile. Both stores are superfluous. The hack to replace typeof(ptr->counter) with int in __CS_LOOP and and long long in __CSG_LOOP avoids the two stores. A better solution would be to drop the volatile from the counter field of the atomic_t and atomic64_t definition. But that is a touchy subject .. Cc: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] atomic ops: small cleanupsHeiko Carstens1-22/+19
Couple of coding style fixes, replace __inline__ with inline and remove #ifdef __KERNEL_- since the header file isn't exported. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] atomic ops: add effecient atomic64 support for 31 bitHeiko Carstens1-37/+127
Use compare double and swap to implement efficient atomic64 ops for 31 bit. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-07-07[S390] add generic atomic64 support for 31 bitHeiko Carstens1-1/+6
Performance counters need 64 bit atomic operations. To keep the patch small we use the simple generic atomic64_t implementation. The native implementation follows with the next kernel. Fixes this build bug: In file included from kernel/sched.c:42: include/linux/perf_counter.h:427: error: expected specifier-qualifier-list before 'atomic64_t' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-11asm-generic: rename atomic.h to atomic-long.hArnd Bergmann1-1/+1
The existing asm-generic/atomic.h only defines the atomic_long type. This renames it to atomic-long.h so we have a place to add a truly generic atomic.h that can be used on all non-SMP systems. Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-01-06atomic_t: unify all arch definitionsMatthew Wilcox1-6/+1
The atomic_t type cannot currently be used in some header files because it would create an include loop with asm/atomic.h. Move the type definition to linux/types.h to break the loop. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-01[S390] move include/asm-s390 to arch/s390/include/asmMartin Schwidefsky1-0/+285
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>