Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1410135

[PATCH -v2 11/33] locking,hexagon: Implement atomic_fetch_{add,sub,and,or,xor}()

From Peter Zijlstra <peterz@infradead.org>
Newsgroups linux.kernel
Subject [PATCH -v2 11/33] locking,hexagon: Implement atomic_fetch_{add,sub,and,or,xor}()
Date 2016-05-31 12:50 +0200
Message-ID <rEPpg-1AT-23@gated-at.bofh.it> (permalink)
References <rEPfz-1vx-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


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>
---
 arch/hexagon/include/asm/atomic.h |   33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

--- a/arch/hexagon/include/asm/atomic.h
+++ b/arch/hexagon/include/asm/atomic.h
@@ -110,7 +110,7 @@ static inline void atomic_##op(int i, at
 	);								\
 }									\
 
-#define ATOMIC_OP_RETURN(op)							\
+#define ATOMIC_OP_RETURN(op)						\
 static inline int atomic_##op##_return(int i, atomic_t *v)		\
 {									\
 	int output;							\
@@ -127,16 +127,39 @@ static inline int atomic_##op##_return(i
 	return output;							\
 }
 
-#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
+#define ATOMIC_FETCH_OP(op)						\
+static inline int atomic_fetch_##op(int i, atomic_t *v)			\
+{									\
+	int output, val;						\
+									\
+	__asm__ __volatile__ (						\
+		"1:	%0 = memw_locked(%2);\n"			\
+		"	%1 = "#op "(%0,%3);\n"				\
+		"	memw_locked(%2,P3)=%1;\n"			\
+		"	if !P3 jump 1b;\n"				\
+		: "=&r" (output), "=&r" (val)				\
+		: "r" (&v->counter), "r" (i)				\
+		: "memory", "p3"					\
+	);								\
+	return output;							\
+}
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
 
 ATOMIC_OPS(add)
 ATOMIC_OPS(sub)
 
-ATOMIC_OP(and)
-ATOMIC_OP(or)
-ATOMIC_OP(xor)
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
+
+#define atomic_fetch_or atomic_fetch_or
+
+ATOMIC_OPS(and)
+ATOMIC_OPS(or)
+ATOMIC_OPS(xor)
 
 #undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
 #undef ATOMIC_OP_RETURN
 #undef ATOMIC_OP
 

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH -v2 00/33] implement atomic_fetch_$op Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 23/33] locking,tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 31/33] locking,mips: Convert to _relaxed atomics Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 01/33] locking,alpha: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 17/33] locking,mn10300: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 07/33] locking,avr32: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 29/33] locking: Remove the deprecated atomic_{set,clear}_mask() functions Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 21/33] locking,sh: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 30/33] locking,alpha: Convert to _relaxed atomics Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 02/33] locking,arc: Implement atomic_fetch_{add,sub,and,andnot,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 08/33] locking,blackfin: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 16/33] locking,mips: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 05/33] arm64: atomic: generate LSE non-return cases using common macros Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 10/33] locking,h8300: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 22/33] locking,sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
    Re: [PATCH -v2 22/33] locking,sparc: Implement  atomic{,64}_fetch_{add,sub,and,or,xor}() David Miller <davem@davemloft.net> - 2016-05-31 20:00 +0200
  [PATCH -v2 12/33] locking,ia64: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 04/33] locking,arm64: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 33/33] locking,rwsem: Employ atomic_long_fetch_add() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 13/33] locking,m32r: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 06/33] locking,arm64: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() for LSE instructions Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 26/33] locking: Fix atomic64_relaxed bits Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 27/33] locking: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:40 +0200
  [PATCH -v2 11/33] locking,hexagon: Implement atomic_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:50 +0200
  [PATCH -v2 20/33] locking,s390: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:50 +0200
  Re: [PATCH -v2 00/33] implement atomic_fetch_$op Will Deacon <will.deacon@arm.com> - 2016-06-01 16:10 +0200
  Re: [PATCH -v2 00/33] implement atomic_fetch_$op Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2016-06-02 11:30 +0200
    Re: [PATCH -v2 00/33] implement atomic_fetch_$op Peter Zijlstra <peterz@infradead.org> - 2016-06-02 11:40 +0200
      Re: [PATCH -v2 00/33] implement atomic_fetch_$op Peter Zijlstra <peterz@infradead.org> - 2016-06-08 14:50 +0200
        Re: [PATCH -v2 00/33] implement atomic_fetch_$op Ingo Molnar <mingo@kernel.org> - 2016-06-08 15:00 +0200
          Re: [PATCH -v2 00/33] implement atomic_fetch_$op Peter Zijlstra <peterz@infradead.org> - 2016-06-08 15:40 +0200
            Re: [PATCH -v2 00/33] implement atomic_fetch_$op Vineet Gupta <vgupta@synopsys.com> - 2016-06-08 16:30 +0200
              Re: [PATCH -v2 00/33] implement atomic_fetch_$op Peter Zijlstra <peterz@infradead.org> - 2016-06-08 16:40 +0200

csiph-web