kernel/arch/powerpc/include/asm/atomic.h, branch linux-4.3.y

atomic: Provide atomic_{or,xor,and}

2015-07-27T12:06:24Z

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) Signed-off-by: Thomas Gleixner

powerpc: Provide atomic_{or,xor,and}

2015-07-27T12:06:23Z

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 Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner

locking,arch,powerpc: Fold atomic_ops

2014-08-14T10:48:11Z

Many of the atomic op implementations are the same except for one instruction; fold the lot into a few CPP macros and reduce LoC. Requires asm_op because PPC asm is weird :-) Signed-off-by: Peter Zijlstra Cc: Benjamin Herrenschmidt Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Paul Mackerras Cc: Mahesh Salgaonkar Cc: Paul Gortmaker Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20140508135852.713980957@infradead.org Signed-off-by: Ingo Molnar

arch,powerpc: Convert smp_mb__*()

2014-04-18T12:20:41Z

Powerpc allows reordering over its ll/sc implementation. Implement the two new barriers as appropriate. Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-gg2ffgq32sjgy9b8lj6m3hsc@git.kernel.org Cc: Benjamin Herrenschmidt Cc: Linus Torvalds Cc: Mahesh Salgaonkar Cc: Paul Gortmaker Cc: Paul Mackerras Cc: Will Deacon Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Ingo Molnar

atomic: implement generic atomic_dec_if_positive()

2012-10-09T07:22:46Z

The x86 implementation of atomic_dec_if_positive is quite generic, so make it available to all architectures. This is needed for "swap: add a simple detector for inappropriate swapin readahead". [akpm@linux-foundation.org: do the "#define foo foo" trick in the conventional manner] Signed-off-by: Shaohua Li Cc: Stephen Rothwell Cc: "David S. Miller" Cc: Rik van Riel Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Benjamin Herrenschmidt Cc: Michal Simek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Disintegrate asm/system.h for PowerPC

2012-03-28T17:30:02Z

Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells Acked-by: Benjamin Herrenschmidt cc: linuxppc-dev@lists.ozlabs.org

powerpc/atomic: Implement atomic*_inc_not_zero

2012-03-07T06:06:08Z

Implement atomic_inc_not_zero and atomic64_inc_not_zero. At the moment we use atomic*_add_unless which requires us to put 0 and 1 constants into registers. We can also avoid a subtract by saving the original value in a second temporary. This removes 3 instructions from fget: - c0000000001b63c0: 39 00 00 00 li r8,0 - c0000000001b63c4: 39 40 00 01 li r10,1 ... - c0000000001b63e8: 7c 0a 00 50 subf r0,r10,r0 Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix atomic_xxx_return barrier semantics

2011-11-17T05:26:07Z

The Documentation/memory-barriers.txt document requires that atomic operations that return a value act as a memory barrier both before and after the actual atomic operation. Our current implementation doesn't guarantee this. More specifically, while a load following the isync can not be issued before stwcx. has completed, that completion doesn't architecturally means that the result of stwcx. is visible to other processors (or any previous stores for that matter) (typically, the other processors L1 caches can still hold the old value). This has caused an actual crash in RCU torture testing on Power 7 This fixes it by changing those atomic ops to use new macros instead of RELEASE/ACQUIRE barriers, called ATOMIC_ENTRY and ATMOIC_EXIT barriers, which are then defined respectively to lwsync and sync. I haven't had a chance to measure the performance impact (or rather what I measured with kernel compiles is in the noise, I yet have to find a more precise benchmark) Signed-off-by: Benjamin Herrenschmidt Acked-by: Paul E. McKenney

atomic: cleanup asm-generic atomic*.h inclusion

2011-07-26T23:49:47Z

After changing all consumers of atomics to include , 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 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 Cc: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

atomic: move atomic_add_unless to generic code

2011-07-26T23:49:47Z

This is in preparation for more generic atomic primitives based on __atomic_add_unless. Signed-off-by: Arun Sharma Signed-off-by: Hans-Christian Egtvedt Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds