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304a0d699a
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>
111 lines
2.6 KiB
ArmAsm
111 lines
2.6 KiB
ArmAsm
/* atomic.S: These things are too big to do inline.
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*
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* Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net)
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*/
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#include <linux/linkage.h>
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#include <asm/asi.h>
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#include <asm/backoff.h>
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.text
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/* Two versions of the atomic routines, one that
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* does not return a value and does not perform
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* memory barriers, and a second which returns
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* a value and does the barriers.
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*/
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#define ATOMIC_OP(op) \
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ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
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BACKOFF_SETUP(%o2); \
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1: lduw [%o1], %g1; \
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op %g1, %o0, %g7; \
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cas [%o1], %g1, %g7; \
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cmp %g1, %g7; \
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bne,pn %icc, BACKOFF_LABEL(2f, 1b); \
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nop; \
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retl; \
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nop; \
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2: BACKOFF_SPIN(%o2, %o3, 1b); \
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ENDPROC(atomic_##op); \
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#define ATOMIC_OP_RETURN(op) \
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ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
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BACKOFF_SETUP(%o2); \
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1: lduw [%o1], %g1; \
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op %g1, %o0, %g7; \
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cas [%o1], %g1, %g7; \
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cmp %g1, %g7; \
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bne,pn %icc, BACKOFF_LABEL(2f, 1b); \
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op %g1, %o0, %g1; \
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retl; \
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sra %g1, 0, %o0; \
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2: BACKOFF_SPIN(%o2, %o3, 1b); \
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ENDPROC(atomic_##op##_return);
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#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
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ATOMIC_OPS(add)
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ATOMIC_OPS(sub)
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ATOMIC_OP(and)
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ATOMIC_OP(or)
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ATOMIC_OP(xor)
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#undef ATOMIC_OPS
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#undef ATOMIC_OP_RETURN
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#undef ATOMIC_OP
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#define ATOMIC64_OP(op) \
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ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */ \
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BACKOFF_SETUP(%o2); \
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1: ldx [%o1], %g1; \
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op %g1, %o0, %g7; \
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casx [%o1], %g1, %g7; \
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cmp %g1, %g7; \
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bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \
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nop; \
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retl; \
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nop; \
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2: BACKOFF_SPIN(%o2, %o3, 1b); \
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ENDPROC(atomic64_##op); \
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#define ATOMIC64_OP_RETURN(op) \
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ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */ \
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BACKOFF_SETUP(%o2); \
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1: ldx [%o1], %g1; \
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op %g1, %o0, %g7; \
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casx [%o1], %g1, %g7; \
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cmp %g1, %g7; \
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bne,pn %xcc, BACKOFF_LABEL(2f, 1b); \
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nop; \
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retl; \
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op %g1, %o0, %o0; \
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2: BACKOFF_SPIN(%o2, %o3, 1b); \
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ENDPROC(atomic64_##op##_return);
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#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
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ATOMIC64_OPS(add)
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ATOMIC64_OPS(sub)
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ATOMIC64_OP(and)
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ATOMIC64_OP(or)
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ATOMIC64_OP(xor)
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#undef ATOMIC64_OPS
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#undef ATOMIC64_OP_RETURN
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#undef ATOMIC64_OP
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ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
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BACKOFF_SETUP(%o2)
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1: ldx [%o0], %g1
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brlez,pn %g1, 3f
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sub %g1, 1, %g7
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casx [%o0], %g1, %g7
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cmp %g1, %g7
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bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
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nop
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3: retl
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sub %g1, 1, %o0
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2: BACKOFF_SPIN(%o2, %o3, 1b)
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ENDPROC(atomic64_dec_if_positive)
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