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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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62e8a3258b
This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().
We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().
And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.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: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
118 lines
3.0 KiB
C
118 lines
3.0 KiB
C
/* atomic.h: Thankfully the V9 is at least reasonable for this
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* stuff.
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*
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* Copyright (C) 1996, 1997, 2000, 2012 David S. Miller (davem@redhat.com)
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*/
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#ifndef __ARCH_SPARC64_ATOMIC__
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#define __ARCH_SPARC64_ATOMIC__
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#include <linux/types.h>
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#include <asm/cmpxchg.h>
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#include <asm/barrier.h>
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#define ATOMIC_INIT(i) { (i) }
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#define ATOMIC64_INIT(i) { (i) }
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#define atomic_read(v) READ_ONCE((v)->counter)
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#define atomic64_read(v) READ_ONCE((v)->counter)
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#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
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#define atomic64_set(v, i) WRITE_ONCE(((v)->counter), (i))
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#define ATOMIC_OP(op) \
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void atomic_##op(int, atomic_t *); \
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void atomic64_##op(long, atomic64_t *);
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#define ATOMIC_OP_RETURN(op) \
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int atomic_##op##_return(int, atomic_t *); \
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long atomic64_##op##_return(long, atomic64_t *);
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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 atomic_dec_return(v) atomic_sub_return(1, v)
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#define atomic64_dec_return(v) atomic64_sub_return(1, v)
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#define atomic_inc_return(v) atomic_add_return(1, v)
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#define atomic64_inc_return(v) atomic64_add_return(1, v)
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/*
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* atomic_inc_and_test - increment and test
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* @v: pointer of type atomic_t
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*
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* Atomically increments @v by 1
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* and returns true if the result is zero, or false for all
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* other cases.
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*/
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#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
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#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
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#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
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#define atomic64_sub_and_test(i, v) (atomic64_sub_return(i, v) == 0)
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#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
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#define atomic64_dec_and_test(v) (atomic64_sub_return(1, v) == 0)
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#define atomic_inc(v) atomic_add(1, v)
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#define atomic64_inc(v) atomic64_add(1, v)
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#define atomic_dec(v) atomic_sub(1, v)
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#define atomic64_dec(v) atomic64_sub(1, v)
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#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
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#define atomic64_add_negative(i, v) (atomic64_add_return(i, v) < 0)
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#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
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#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
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static inline int __atomic_add_unless(atomic_t *v, int a, int u)
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{
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int c, old;
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c = atomic_read(v);
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for (;;) {
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if (unlikely(c == (u)))
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break;
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old = atomic_cmpxchg((v), c, c + (a));
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if (likely(old == c))
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break;
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c = old;
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}
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return c;
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}
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#define atomic64_cmpxchg(v, o, n) \
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((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
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#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
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static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
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{
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long c, old;
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c = atomic64_read(v);
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for (;;) {
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if (unlikely(c == (u)))
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break;
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old = atomic64_cmpxchg((v), c, c + (a));
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if (likely(old == c))
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break;
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c = old;
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}
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return c != (u);
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}
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#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
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long atomic64_dec_if_positive(atomic64_t *v);
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#endif /* !(__ARCH_SPARC64_ATOMIC__) */
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