mirror of
https://github.com/checkpoint-restore/criu.git
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70833bcf29
Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Adrian Reber <areber@redhat.com>
103 lines
2.1 KiB
C
103 lines
2.1 KiB
C
#ifndef __CR_ATOMIC_H__
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#define __CR_ATOMIC_H__
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typedef struct {
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int counter;
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} atomic_t;
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/* Copied from the Linux header arch/arm/include/asm/barrier.h */
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#define smp_mb() asm volatile("dmb ish" : : : "memory")
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/* Copied from the Linux kernel header arch/arm64/include/asm/atomic.h */
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static inline int atomic_read(const atomic_t *v)
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{
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return (*(volatile int *)&(v)->counter);
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}
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static inline void atomic_set(atomic_t *v, int i)
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{
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v->counter = i;
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}
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#define atomic_get atomic_read
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static inline int atomic_add_return(int i, atomic_t *v)
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{
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unsigned long tmp;
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int result;
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asm volatile("1: ldxr %w0, %2\n"
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" add %w0, %w0, %w3\n"
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" stlxr %w1, %w0, %2\n"
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" cbnz %w1, 1b"
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: "=&r"(result), "=&r"(tmp), "+Q"(v->counter)
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: "Ir"(i)
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: "cc", "memory");
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smp_mb();
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return result;
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}
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static inline int atomic_sub_return(int i, atomic_t *v)
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{
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unsigned long tmp;
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int result;
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asm volatile("1: ldxr %w0, %2\n"
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" sub %w0, %w0, %w3\n"
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" stlxr %w1, %w0, %2\n"
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" cbnz %w1, 1b"
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: "=&r"(result), "=&r"(tmp), "+Q"(v->counter)
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: "Ir"(i)
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: "cc", "memory");
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smp_mb();
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return result;
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}
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static inline int atomic_inc(atomic_t *v)
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{
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return atomic_add_return(1, v) - 1;
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}
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static inline int atomic_add(int val, atomic_t *v)
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{
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return atomic_add_return(val, v) - val;
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}
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static inline int atomic_dec(atomic_t *v)
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{
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return atomic_sub_return(1, v) + 1;
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}
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/* true if the result is 0, or false for all other cases. */
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#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
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#define atomic_dec_return(v) (atomic_sub_return(1, v))
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#define atomic_inc_return(v) (atomic_add_return(1, v))
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static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
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{
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unsigned long tmp;
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int oldval;
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smp_mb();
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asm volatile("// atomic_cmpxchg\n"
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"1: ldxr %w1, %2\n"
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" cmp %w1, %w3\n"
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" b.ne 2f\n"
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" stxr %w0, %w4, %2\n"
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" cbnz %w0, 1b\n"
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"2:"
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: "=&r"(tmp), "=&r"(oldval), "+Q"(ptr->counter)
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: "Ir"(old), "r"(new)
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: "cc");
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smp_mb();
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return oldval;
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}
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#endif /* __CR_ATOMIC_H__ */
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