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support for read/write-lock and read/write-trylock

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Change-Id: I609071c0f6234d0d413c8b312d8a8379abf6846e
Refs: #1323
This commit is contained in:
Tomoki Shirasawa
2019-07-29 14:11:13 +09:00
committed by Masamichi Takagi
parent 8efced7bf7
commit 258156b57e
9 changed files with 570 additions and 0 deletions
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97
arch/arm64/kernel/include/arch-lock.h
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@ -659,5 +659,102 @@ static inline int irqflags_can_interrupt(unsigned long flags)
}
#endif /* CONFIG_HAS_NMI */
struct ihk_rwlock {
unsigned int lock;
};
static inline void ihk_mc_rwlock_init(struct ihk_rwlock *rw)
{
rw->lock = 0;
}
static inline void ihk_mc_read_lock(struct ihk_rwlock *rw)
{
unsigned int tmp, tmp2;
asm volatile(
" sevl\n"
"1: wfe\n"
"2: ldaxr %w0, %2\n"
" add %w0, %w0, #1\n"
" tbnz %w0, #31, 1b\n"
" stxr %w1, %w0, %2\n"
" cbnz %w1, 2b\n"
: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
:
: "cc", "memory");
}
static inline int ihk_mc_read_trylock(struct ihk_rwlock *rw)
{
unsigned int tmp, tmp2 = 1;
asm volatile(
" ldaxr %w0, %2\n"
" add %w0, %w0, #1\n"
" tbnz %w0, #31, 1f\n"
" stxr %w1, %w0, %2\n"
"1:\n"
: "=&r" (tmp), "+r" (tmp2), "+Q" (rw->lock)
:
: "cc", "memory");
return !tmp2;
}
static inline void ihk_mc_read_unlock(struct ihk_rwlock *rw)
{
unsigned int tmp, tmp2;
asm volatile(
"1: ldxr %w0, %2\n"
" sub %w0, %w0, #1\n"
" stlxr %w1, %w0, %2\n"
" cbnz %w1, 1b\n"
: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
:
: "cc", "memory");
}
static inline void ihk_mc_write_lock(struct ihk_rwlock *rw)
{
unsigned int tmp;
asm volatile(
" sevl\n"
"1: wfe\n"
"2: ldaxr %w0, %1\n"
" cbnz %w0, 1b\n"
" stxr %w0, %w2, %1\n"
" cbnz %w0, 2b\n"
: "=&r" (tmp), "+Q" (rw->lock)
: "r" (0x80000000)
: "cc", "memory");
}
static inline int ihk_mc_write_trylock(struct ihk_rwlock *rw)
{
unsigned int tmp;
asm volatile(
" ldaxr %w0, %1\n"
" cbnz %w0, 1f\n"
" stxr %w0, %w2, %1\n"
"1:\n"
: "=&r" (tmp), "+Q" (rw->lock)
: "r" (0x80000000)
: "cc", "memory");
return !tmp;
}
static inline void ihk_mc_write_unlock(struct ihk_rwlock *rw)
{
asm volatile(
" stlr %w1, %0\n"
: "=Q" (rw->lock) : "r" (0) : "memory");
}
#define ihk_mc_read_can_lock(rw) ((rw)->lock < 0x80000000)
#define ihk_mc_write_can_lock(rw) ((rw)->lock == 0)
#endif /* !__HEADER_ARM64_COMMON_ARCH_LOCK_H */