support for read/write-lock and read/write-trylock
Change-Id: I609071c0f6234d0d413c8b312d8a8379abf6846e Refs: #1323
This commit is contained in:
Tomoki Shirasawa
committed by
Masamichi Takagi
Masamichi Takagi
parent
8efced7bf7
commit
258156b57e
@ -659,5 +659,102 @@ static inline int irqflags_can_interrupt(unsigned long flags)
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}
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#endif /* CONFIG_HAS_NMI */
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struct ihk_rwlock {
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unsigned int lock;
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};
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static inline void ihk_mc_rwlock_init(struct ihk_rwlock *rw)
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{
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rw->lock = 0;
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}
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static inline void ihk_mc_read_lock(struct ihk_rwlock *rw)
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{
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unsigned int tmp, tmp2;
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asm volatile(
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" sevl\n"
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"1: wfe\n"
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"2: ldaxr %w0, %2\n"
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" add %w0, %w0, #1\n"
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" tbnz %w0, #31, 1b\n"
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" stxr %w1, %w0, %2\n"
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" cbnz %w1, 2b\n"
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: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
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:
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: "cc", "memory");
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}
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static inline int ihk_mc_read_trylock(struct ihk_rwlock *rw)
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{
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unsigned int tmp, tmp2 = 1;
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asm volatile(
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" ldaxr %w0, %2\n"
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" add %w0, %w0, #1\n"
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" tbnz %w0, #31, 1f\n"
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" stxr %w1, %w0, %2\n"
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"1:\n"
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: "=&r" (tmp), "+r" (tmp2), "+Q" (rw->lock)
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:
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: "cc", "memory");
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return !tmp2;
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}
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static inline void ihk_mc_read_unlock(struct ihk_rwlock *rw)
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{
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unsigned int tmp, tmp2;
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asm volatile(
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"1: ldxr %w0, %2\n"
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" sub %w0, %w0, #1\n"
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" stlxr %w1, %w0, %2\n"
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" cbnz %w1, 1b\n"
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: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
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:
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: "cc", "memory");
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}
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static inline void ihk_mc_write_lock(struct ihk_rwlock *rw)
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{
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unsigned int tmp;
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asm volatile(
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" sevl\n"
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"1: wfe\n"
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"2: ldaxr %w0, %1\n"
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" cbnz %w0, 1b\n"
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" stxr %w0, %w2, %1\n"
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" cbnz %w0, 2b\n"
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: "=&r" (tmp), "+Q" (rw->lock)
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: "r" (0x80000000)
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: "cc", "memory");
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}
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static inline int ihk_mc_write_trylock(struct ihk_rwlock *rw)
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{
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unsigned int tmp;
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asm volatile(
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" ldaxr %w0, %1\n"
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" cbnz %w0, 1f\n"
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" stxr %w0, %w2, %1\n"
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"1:\n"
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: "=&r" (tmp), "+Q" (rw->lock)
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: "r" (0x80000000)
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: "cc", "memory");
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return !tmp;
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}
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static inline void ihk_mc_write_unlock(struct ihk_rwlock *rw)
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{
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asm volatile(
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" stlr %w1, %0\n"
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: "=Q" (rw->lock) : "r" (0) : "memory");
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}
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#define ihk_mc_read_can_lock(rw) ((rw)->lock < 0x80000000)
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#define ihk_mc_write_can_lock(rw) ((rw)->lock == 0)
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#endif /* !__HEADER_ARM64_COMMON_ARCH_LOCK_H */
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@ -592,4 +592,90 @@ static inline int irqflags_can_interrupt(unsigned long flags)
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return !!(flags & 0x200);
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}
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struct ihk_rwlock {
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union {
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long lock;
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struct {
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unsigned int read;
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int write;
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};
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} lock;
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};
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static inline void ihk_mc_rwlock_init(struct ihk_rwlock *rw)
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{
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rw->lock.read = 0;
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rw->lock.write = 1;
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}
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static inline void ihk_mc_read_lock(struct ihk_rwlock *rw)
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{
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asm volatile("1:\t"
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"lock; decq %0\n\t"
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"jns 3f\n\t"
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"lock incq %0\n\t"
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"2:\t"
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"pause\n\t"
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"cmpq $0x1, %0\n\t"
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"jns 1b\n\t"
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"jmp 2b\n\t"
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"3:"
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: "+m" (rw->lock.lock) : : "memory");
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}
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static inline void ihk_mc_write_lock(struct ihk_rwlock *rw)
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{
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asm volatile("1:\t"
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"lock; decl %0\n\t"
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"je 3f\n\t"
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"lock; incl %0\n\t"
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"2:\t"
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"pause\n\t"
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"cmpl $0x1,%0\n\t"
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"je 1b\n\t"
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"jmp 2b\n\t"
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"3:"
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: "+m" (rw->lock.write) : "i" (((1L) << 32)) : "memory");
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}
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static inline int ihk_mc_read_trylock(struct ihk_rwlock *rw)
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{
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ihk_atomic64_t *count = (ihk_atomic64_t *)rw;
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if (ihk_atomic64_sub_return(1, count) >= 0)
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return 1;
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ihk_atomic64_inc(count);
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return 0;
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}
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static inline int ihk_mc_write_trylock(struct ihk_rwlock *rw)
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{
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ihk_atomic_t *count = (ihk_atomic_t *)&rw->lock.write;
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if (ihk_atomic_dec_and_test(count))
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return 1;
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ihk_atomic_inc(count);
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return 0;
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}
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static inline void ihk_mc_read_unlock(struct ihk_rwlock *rw)
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{
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asm volatile("lock; incq %0" : "+m" (rw->lock.lock) : : "memory");
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}
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static inline void ihk_mc_write_unlock(struct ihk_rwlock *rw)
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{
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asm volatile("lock; incl %0"
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: "+m" (rw->lock.write) : "i" (((1L) << 32)) : "memory");
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}
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static inline int ihk_mc_write_can_lock(struct ihk_rwlock *rw)
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{
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return rw->lock.write == 1;
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}
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static inline int ihk_mc_read_can_lock(struct ihk_rwlock *rw)
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{
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return rw->lock.lock > 0;
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}
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#endif
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@ -126,6 +126,22 @@ static inline void ihk_atomic64_inc(ihk_atomic64_t *v)
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asm volatile ("lock incq %0" : "+m"(v->counter64));
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}
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static inline long ihk_atomic64_add_return(long i, ihk_atomic64_t *v)
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{
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long __i;
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__i = i;
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asm volatile("lock xaddq %0, %1"
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: "+r" (i), "+m" (v->counter64)
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: : "memory");
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return i + __i;
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}
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static inline long ihk_atomic64_sub_return(long i, ihk_atomic64_t *v)
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{
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return ihk_atomic64_add_return(-i, v);
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}
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/***********************************************************************
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* others
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*/
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