diff options
Diffstat (limited to 'arch/arm64/include/asm/spinlock.h')
-rw-r--r-- | arch/arm64/include/asm/spinlock.h | 117 |
1 files changed, 1 insertions, 116 deletions
diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index 26c5bd7d88d8..38116008d18b 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -16,123 +16,8 @@ #ifndef __ASM_SPINLOCK_H #define __ASM_SPINLOCK_H -#include <asm/lse.h> -#include <asm/spinlock_types.h> -#include <asm/processor.h> - -/* - * Spinlock implementation. - * - * The memory barriers are implicit with the load-acquire and store-release - * instructions. - */ - -static inline void arch_spin_lock(arch_spinlock_t *lock) -{ - unsigned int tmp; - arch_spinlock_t lockval, newval; - - asm volatile( - /* Atomically increment the next ticket. */ - ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ -" prfm pstl1strm, %3\n" -"1: ldaxr %w0, %3\n" -" add %w1, %w0, %w5\n" -" stxr %w2, %w1, %3\n" -" cbnz %w2, 1b\n", - /* LSE atomics */ -" mov %w2, %w5\n" -" ldadda %w2, %w0, %3\n" - __nops(3) - ) - - /* Did we get the lock? */ -" eor %w1, %w0, %w0, ror #16\n" -" cbz %w1, 3f\n" - /* - * No: spin on the owner. Send a local event to avoid missing an - * unlock before the exclusive load. - */ -" sevl\n" -"2: wfe\n" -" ldaxrh %w2, %4\n" -" eor %w1, %w2, %w0, lsr #16\n" -" cbnz %w1, 2b\n" - /* We got the lock. Critical section starts here. */ -"3:" - : "=&r" (lockval), "=&r" (newval), "=&r" (tmp), "+Q" (*lock) - : "Q" (lock->owner), "I" (1 << TICKET_SHIFT) - : "memory"); -} - -static inline int arch_spin_trylock(arch_spinlock_t *lock) -{ - unsigned int tmp; - arch_spinlock_t lockval; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - " prfm pstl1strm, %2\n" - "1: ldaxr %w0, %2\n" - " eor %w1, %w0, %w0, ror #16\n" - " cbnz %w1, 2f\n" - " add %w0, %w0, %3\n" - " stxr %w1, %w0, %2\n" - " cbnz %w1, 1b\n" - "2:", - /* LSE atomics */ - " ldr %w0, %2\n" - " eor %w1, %w0, %w0, ror #16\n" - " cbnz %w1, 1f\n" - " add %w1, %w0, %3\n" - " casa %w0, %w1, %2\n" - " sub %w1, %w1, %3\n" - " eor %w1, %w1, %w0\n" - "1:") - : "=&r" (lockval), "=&r" (tmp), "+Q" (*lock) - : "I" (1 << TICKET_SHIFT) - : "memory"); - - return !tmp; -} - -static inline void arch_spin_unlock(arch_spinlock_t *lock) -{ - unsigned long tmp; - - asm volatile(ARM64_LSE_ATOMIC_INSN( - /* LL/SC */ - " ldrh %w1, %0\n" - " add %w1, %w1, #1\n" - " stlrh %w1, %0", - /* LSE atomics */ - " mov %w1, #1\n" - " staddlh %w1, %0\n" - __nops(1)) - : "=Q" (lock->owner), "=&r" (tmp) - : - : "memory"); -} - -static inline int arch_spin_value_unlocked(arch_spinlock_t lock) -{ - return lock.owner == lock.next; -} - -static inline int arch_spin_is_locked(arch_spinlock_t *lock) -{ - return !arch_spin_value_unlocked(READ_ONCE(*lock)); -} - -static inline int arch_spin_is_contended(arch_spinlock_t *lock) -{ - arch_spinlock_t lockval = READ_ONCE(*lock); - return (lockval.next - lockval.owner) > 1; -} -#define arch_spin_is_contended arch_spin_is_contended - #include <asm/qrwlock.h> +#include <asm/qspinlock.h> /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() |