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[PATCH -v2 08/33] locking,blackfin: Implement atomic_fetch_{add,sub,and,or,xor}()

From Peter Zijlstra <peterz@infradead.org>
Newsgroups linux.kernel
Subject [PATCH -v2 08/33] locking,blackfin: Implement atomic_fetch_{add,sub,and,or,xor}()
Date 2016-05-31 12:40 +0200
Message-ID <rEPfC-1vx-101@gated-at.bofh.it> (permalink)
References <rEPfz-1vx-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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/blackfin/include/asm/atomic.h |    8 ++++++
 arch/blackfin/kernel/bfin_ksyms.c  |    1 
 arch/blackfin/mach-bf561/atomic.S  |   43 ++++++++++++++++++++++++++-----------
 3 files changed, 40 insertions(+), 12 deletions(-)

--- a/arch/blackfin/include/asm/atomic.h
+++ b/arch/blackfin/include/asm/atomic.h
@@ -17,6 +17,7 @@
 
 asmlinkage int __raw_uncached_fetch_asm(const volatile int *ptr);
 asmlinkage int __raw_atomic_add_asm(volatile int *ptr, int value);
+asmlinkage int __raw_atomic_xadd_asm(volatile int *ptr, int value);
 
 asmlinkage int __raw_atomic_and_asm(volatile int *ptr, int value);
 asmlinkage int __raw_atomic_or_asm(volatile int *ptr, int value);
@@ -28,10 +29,17 @@ asmlinkage int __raw_atomic_test_asm(con
 #define atomic_add_return(i, v) __raw_atomic_add_asm(&(v)->counter, i)
 #define atomic_sub_return(i, v) __raw_atomic_add_asm(&(v)->counter, -(i))
 
+#define atomic_fetch_add(i, v) __raw_atomic_xadd_asm(&(v)->counter, i)
+#define atomic_fetch_sub(i, v) __raw_atomic_xadd_asm(&(v)->counter, -(i))
+
 #define atomic_or(i, v)  (void)__raw_atomic_or_asm(&(v)->counter, i)
 #define atomic_and(i, v) (void)__raw_atomic_and_asm(&(v)->counter, i)
 #define atomic_xor(i, v) (void)__raw_atomic_xor_asm(&(v)->counter, i)
 
+#define atomic_fetch_or(i, v)  __raw_atomic_or_asm(&(v)->counter, i)
+#define atomic_fetch_and(i, v) __raw_atomic_and_asm(&(v)->counter, i)
+#define atomic_fetch_xor(i, v) __raw_atomic_xor_asm(&(v)->counter, i)
+
 #endif
 
 #include <asm-generic/atomic.h>
--- a/arch/blackfin/kernel/bfin_ksyms.c
+++ b/arch/blackfin/kernel/bfin_ksyms.c
@@ -84,6 +84,7 @@ EXPORT_SYMBOL(insl_16);
 
 #ifdef CONFIG_SMP
 EXPORT_SYMBOL(__raw_atomic_add_asm);
+EXPORT_SYMBOL(__raw_atomic_xadd_asm);
 EXPORT_SYMBOL(__raw_atomic_and_asm);
 EXPORT_SYMBOL(__raw_atomic_or_asm);
 EXPORT_SYMBOL(__raw_atomic_xor_asm);
--- a/arch/blackfin/mach-bf561/atomic.S
+++ b/arch/blackfin/mach-bf561/atomic.S
@@ -607,6 +607,28 @@ ENDPROC(___raw_atomic_add_asm)
 
 /*
  * r0 = ptr
+ * r1 = value
+ *
+ * ADD a signed value to a 32bit word and return the old value atomically.
+ * Clobbers: r3:0, p1:0
+ */
+ENTRY(___raw_atomic_xadd_asm)
+	p1 = r0;
+	r3 = r1;
+	[--sp] = rets;
+	call _get_core_lock;
+	r3 = [p1];
+	r2 = r3 + r2;
+	[p1] = r2;
+	r1 = p1;
+	call _put_core_lock;
+	r0 = r3;
+	rets = [sp++];
+	rts;
+ENDPROC(___raw_atomic_add_asm)
+
+/*
+ * r0 = ptr
  * r1 = mask
  *
  * AND the mask bits from a 32bit word and return the old 32bit value
@@ -618,10 +640,9 @@ ENTRY(___raw_atomic_and_asm)
 	r3 = r1;
 	[--sp] = rets;
 	call _get_core_lock;
-	r2 = [p1];
-	r3 = r2 & r3;
-	[p1] = r3;
-	r3 = r2;
+	r3 = [p1];
+	r2 = r2 & r3;
+	[p1] = r2;
 	r1 = p1;
 	call _put_core_lock;
 	r0 = r3;
@@ -642,10 +663,9 @@ ENTRY(___raw_atomic_or_asm)
 	r3 = r1;
 	[--sp] = rets;
 	call _get_core_lock;
-	r2 = [p1];
-	r3 = r2 | r3;
-	[p1] = r3;
-	r3 = r2;
+	r3 = [p1];
+	r2 = r2 | r3;
+	[p1] = r2;
 	r1 = p1;
 	call _put_core_lock;
 	r0 = r3;
@@ -666,10 +686,9 @@ ENTRY(___raw_atomic_xor_asm)
 	r3 = r1;
 	[--sp] = rets;
 	call _get_core_lock;
-	r2 = [p1];
-	r3 = r2 ^ r3;
-	[p1] = r3;
-	r3 = r2;
+	r3 = [p1];
+	r2 = r2 ^ r3;
+	[p1] = r2;
 	r1 = p1;
 	call _put_core_lock;
 	r0 = r3;

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[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

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