From 579afe866f52adcd921272a224ab36733051059c Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Tue, 1 Jan 2019 14:08:32 -0800 Subject: xtensa: use generic spinlock/rwlock implementation Drop custom spinlock/rwlock code and use ones from asm-generic. This way there is less code duplication (atomic primitives are reused). Signed-off-by: Max Filippov --- arch/xtensa/include/asm/spinlock.h | 185 +------------------------------------ 1 file changed, 3 insertions(+), 182 deletions(-) (limited to 'arch/xtensa/include/asm/spinlock.h') diff --git a/arch/xtensa/include/asm/spinlock.h b/arch/xtensa/include/asm/spinlock.h index c6e1290dcbb7..584b0de6f2ca 100644 --- a/arch/xtensa/include/asm/spinlock.h +++ b/arch/xtensa/include/asm/spinlock.h @@ -12,188 +12,9 @@ #define _XTENSA_SPINLOCK_H #include -#include +#include +#include -/* - * spinlock - * - * There is at most one owner of a spinlock. There are not different - * types of spinlock owners like there are for rwlocks (see below). - * - * When trying to obtain a spinlock, the function "spins" forever, or busy- - * waits, until the lock is obtained. When spinning, presumably some other - * owner will soon give up the spinlock making it available to others. Use - * the trylock functions to avoid spinning forever. - * - * possible values: - * - * 0 nobody owns the spinlock - * 1 somebody owns the spinlock - */ - -#define arch_spin_is_locked(x) ((x)->slock != 0) - -static inline void arch_spin_lock(arch_spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " wsr %0, scompare1\n" - "1: movi %0, 1\n" - " s32c1i %0, %1, 0\n" - " bnez %0, 1b\n" - : "=&a" (tmp) - : "a" (&lock->slock) - : "memory"); -} - -/* Returns 1 if the lock is obtained, 0 otherwise. */ - -static inline int arch_spin_trylock(arch_spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " wsr %0, scompare1\n" - " movi %0, 1\n" - " s32c1i %0, %1, 0\n" - : "=&a" (tmp) - : "a" (&lock->slock) - : "memory"); - - return tmp == 0 ? 1 : 0; -} - -static inline void arch_spin_unlock(arch_spinlock_t *lock) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " s32ri %0, %1, 0\n" - : "=&a" (tmp) - : "a" (&lock->slock) - : "memory"); -} - -/* - * rwlock - * - * Read-write locks are really a more flexible spinlock. They allow - * multiple readers but only one writer. Write ownership is exclusive - * (i.e., all other readers and writers are blocked from ownership while - * there is a write owner). These rwlocks are unfair to writers. Writers - * can be starved for an indefinite time by readers. - * - * possible values: - * - * 0 nobody owns the rwlock - * >0 one or more readers own the rwlock - * (the positive value is the actual number of readers) - * 0x80000000 one writer owns the rwlock, no other writers, no readers - */ - -static inline void arch_write_lock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " wsr %0, scompare1\n" - "1: movi %0, 1\n" - " slli %0, %0, 31\n" - " s32c1i %0, %1, 0\n" - " bnez %0, 1b\n" - : "=&a" (tmp) - : "a" (&rw->lock) - : "memory"); -} - -/* Returns 1 if the lock is obtained, 0 otherwise. */ - -static inline int arch_write_trylock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " wsr %0, scompare1\n" - " movi %0, 1\n" - " slli %0, %0, 31\n" - " s32c1i %0, %1, 0\n" - : "=&a" (tmp) - : "a" (&rw->lock) - : "memory"); - - return tmp == 0 ? 1 : 0; -} - -static inline void arch_write_unlock(arch_rwlock_t *rw) -{ - unsigned long tmp; - - __asm__ __volatile__( - " movi %0, 0\n" - " s32ri %0, %1, 0\n" - : "=&a" (tmp) - : "a" (&rw->lock) - : "memory"); -} - -static inline void arch_read_lock(arch_rwlock_t *rw) -{ - unsigned long tmp; - unsigned long result; - - __asm__ __volatile__( - "1: l32i %1, %2, 0\n" - " bltz %1, 1b\n" - " wsr %1, scompare1\n" - " addi %0, %1, 1\n" - " s32c1i %0, %2, 0\n" - " bne %0, %1, 1b\n" - : "=&a" (result), "=&a" (tmp) - : "a" (&rw->lock) - : "memory"); -} - -/* Returns 1 if the lock is obtained, 0 otherwise. */ - -static inline int arch_read_trylock(arch_rwlock_t *rw) -{ - unsigned long result; - unsigned long tmp; - - __asm__ __volatile__( - " l32i %1, %2, 0\n" - " addi %0, %1, 1\n" - " bltz %0, 1f\n" - " wsr %1, scompare1\n" - " s32c1i %0, %2, 0\n" - " sub %0, %0, %1\n" - "1:\n" - : "=&a" (result), "=&a" (tmp) - : "a" (&rw->lock) - : "memory"); - - return result == 0; -} - -static inline void arch_read_unlock(arch_rwlock_t *rw) -{ - unsigned long tmp1, tmp2; - - __asm__ __volatile__( - "1: l32i %1, %2, 0\n" - " addi %0, %1, -1\n" - " wsr %1, scompare1\n" - " s32c1i %0, %2, 0\n" - " bne %0, %1, 1b\n" - : "=&a" (tmp1), "=&a" (tmp2) - : "a" (&rw->lock) - : "memory"); -} +#define smp_mb__after_spinlock() smp_mb() #endif /* _XTENSA_SPINLOCK_H */ -- cgit v1.2.3-59-g8ed1b