#ifndef _ASM_M32R_SPINLOCK_H #define _ASM_M32R_SPINLOCK_H /* * linux/include/asm-m32r/spinlock.h * * M32R version: * Copyright (C) 2001, 2002 Hitoshi Yamamoto * Copyright (C) 2004 Hirokazu Takata */ #include /* CONFIG_DEBUG_SPINLOCK, CONFIG_SMP */ #include #include #include extern int printk(const char * fmt, ...) __attribute__ ((format (printf, 1, 2))); #define RW_LOCK_BIAS 0x01000000 #define RW_LOCK_BIAS_STR "0x01000000" /* * Your basic SMP spinlocks, allowing only a single CPU anywhere */ typedef struct { volatile int slock; #ifdef CONFIG_DEBUG_SPINLOCK unsigned magic; #endif #ifdef CONFIG_PREEMPT unsigned int break_lock; #endif } spinlock_t; #define SPINLOCK_MAGIC 0xdead4ead #ifdef CONFIG_DEBUG_SPINLOCK #define SPINLOCK_MAGIC_INIT , SPINLOCK_MAGIC #else #define SPINLOCK_MAGIC_INIT /* */ #endif #define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT } #define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) /* * Simple spin lock operations. There are two variants, one clears IRQ's * on the local processor, one does not. * * We make no fairness assumptions. They have a cost. */ #define spin_is_locked(x) (*(volatile int *)(&(x)->slock) <= 0) #define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x)) #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) /** * _raw_spin_trylock - Try spin lock and return a result * @lock: Pointer to the lock variable * * _raw_spin_trylock() tries to get the lock and returns a result. * On the m32r, the result value is 1 (= Success) or 0 (= Failure). */ static inline int _raw_spin_trylock(spinlock_t *lock) { int oldval; unsigned long tmp1, tmp2; /* * lock->slock : =1 : unlock * : <=0 : lock * { * oldval = lock->slock; <--+ need atomic operation * lock->slock = 0; <--+ * } */ __asm__ __volatile__ ( "# spin_trylock \n\t" "ldi %1, #0; \n\t" "mvfc %2, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r6", "%3") "lock %0, @%3; \n\t" "unlock %1, @%3; \n\t" "mvtc %2, psw; \n\t" : "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2) : "r" (&lock->slock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r6" #endif /* CONFIG_CHIP_M32700_TS1 */ ); return (oldval > 0); } static inline void _raw_spin_lock(spinlock_t *lock) { unsigned long tmp0, tmp1; #ifdef CONFIG_DEBUG_SPINLOCK if (unlikely(lock->magic != SPINLOCK_MAGIC)) { printk("pc: %p\n", __builtin_return_address(0)); BUG(); } #endif /* * lock->slock : =1 : unlock * : <=0 : lock * * for ( ; ; ) { * lock->slock -= 1; <-- need atomic operation * if (lock->slock == 0) break; * for ( ; lock->slock <= 0 ; ); * } */ __asm__ __volatile__ ( "# spin_lock \n\t" ".fillinsn \n" "1: \n\t" "mvfc %1, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r6", "%2") "lock %0, @%2; \n\t" "addi %0, #-1; \n\t" "unlock %0, @%2; \n\t" "mvtc %1, psw; \n\t" "bltz %0, 2f; \n\t" LOCK_SECTION_START(".balign 4 \n\t") ".fillinsn \n" "2: \n\t" "ld %0, @%2; \n\t" "bgtz %0, 1b; \n\t" "bra 2b; \n\t" LOCK_SECTION_END : "=&r" (tmp0), "=&r" (tmp1) : "r" (&lock->slock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r6" #endif /* CONFIG_CHIP_M32700_TS1 */ ); } static inline void _raw_spin_unlock(spinlock_t *lock) { #ifdef CONFIG_DEBUG_SPINLOCK BUG_ON(lock->magic != SPINLOCK_MAGIC); BUG_ON(!spin_is_locked(lock)); #endif mb(); lock->slock = 1; } /* * Read-write spinlocks, allowing multiple readers * but only one writer. * * NOTE! it is quite common to have readers in interrupts * but no interrupt writers. For those circumstances we * can "mix" irq-safe locks - any writer needs to get a * irq-safe write-lock, but readers can get non-irqsafe * read-locks. */ typedef struct { volatile int lock; #ifdef CONFIG_DEBUG_SPINLOCK unsigned magic; #endif #ifdef CONFIG_PREEMPT unsigned int break_lock; #endif } rwlock_t; #define RWLOCK_MAGIC 0xdeaf1eed #ifdef CONFIG_DEBUG_SPINLOCK #define RWLOCK_MAGIC_INIT , RWLOCK_MAGIC #else #define RWLOCK_MAGIC_INIT /* */ #endif #define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT } #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) /** * read_can_lock - would read_trylock() succeed? * @lock: the rwlock in question. */ #define read_can_lock(x) ((int)(x)->lock > 0) /** * write_can_lock - would write_trylock() succeed? * @lock: the rwlock in question. */ #define write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) /* * On x86, we implement read-write locks as a 32-bit counter * with the high bit (sign) being the "contended" bit. * * The inline assembly is non-obvious. Think about it. * * Changed to use the same technique as rw semaphores. See * semaphore.h for details. -ben */ /* the spinlock helpers are in arch/i386/kernel/semaphore.c */ static inline void _raw_read_lock(rwlock_t *rw) { unsigned long tmp0, tmp1; #ifdef CONFIG_DEBUG_SPINLOCK BUG_ON(rw->magic != RWLOCK_MAGIC); #endif /* * rw->lock : >0 : unlock * : <=0 : lock * * for ( ; ; ) { * rw->lock -= 1; <-- need atomic operation * if (rw->lock >= 0) break; * rw->lock += 1; <-- need atomic operation * for ( ; rw->lock <= 0 ; ); * } */ __asm__ __volatile__ ( "# read_lock \n\t" ".fillinsn \n" "1: \n\t" "mvfc %1, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r6", "%2") "lock %0, @%2; \n\t" "addi %0, #-1; \n\t" "unlock %0, @%2; \n\t" "mvtc %1, psw; \n\t" "bltz %0, 2f; \n\t" LOCK_SECTION_START(".balign 4 \n\t") ".fillinsn \n" "2: \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r6", "%2") "lock %0, @%2; \n\t" "addi %0, #1; \n\t" "unlock %0, @%2; \n\t" "mvtc %1, psw; \n\t" ".fillinsn \n" "3: \n\t" "ld %0, @%2; \n\t" "bgtz %0, 1b; \n\t" "bra 3b; \n\t" LOCK_SECTION_END : "=&r" (tmp0), "=&r" (tmp1) : "r" (&rw->lock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r6" #endif /* CONFIG_CHIP_M32700_TS1 */ ); } static inline void _raw_write_lock(rwlock_t *rw) { unsigned long tmp0, tmp1, tmp2; #ifdef CONFIG_DEBUG_SPINLOCK BUG_ON(rw->magic != RWLOCK_MAGIC); #endif /* * rw->lock : =RW_LOCK_BIAS_STR : unlock * : !=RW_LOCK_BIAS_STR : lock * * for ( ; ; ) { * rw->lock -= RW_LOCK_BIAS_STR; <-- need atomic operation * if (rw->lock == 0) break; * rw->lock += RW_LOCK_BIAS_STR; <-- need atomic operation * for ( ; rw->lock != RW_LOCK_BIAS_STR ; ) ; * } */ __asm__ __volatile__ ( "# write_lock \n\t" "seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t" "or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t" ".fillinsn \n" "1: \n\t" "mvfc %2, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r7", "%3") "lock %0, @%3; \n\t" "sub %0, %1; \n\t" "unlock %0, @%3; \n\t" "mvtc %2, psw; \n\t" "bnez %0, 2f; \n\t" LOCK_SECTION_START(".balign 4 \n\t") ".fillinsn \n" "2: \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r7", "%3") "lock %0, @%3; \n\t" "add %0, %1; \n\t" "unlock %0, @%3; \n\t" "mvtc %2, psw; \n\t" ".fillinsn \n" "3: \n\t" "ld %0, @%3; \n\t" "beq %0, %1, 1b; \n\t" "bra 3b; \n\t" LOCK_SECTION_END : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2) : "r" (&rw->lock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r7" #endif /* CONFIG_CHIP_M32700_TS1 */ ); } static inline void _raw_read_unlock(rwlock_t *rw) { unsigned long tmp0, tmp1; __asm__ __volatile__ ( "# read_unlock \n\t" "mvfc %1, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r6", "%2") "lock %0, @%2; \n\t" "addi %0, #1; \n\t" "unlock %0, @%2; \n\t" "mvtc %1, psw; \n\t" : "=&r" (tmp0), "=&r" (tmp1) : "r" (&rw->lock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r6" #endif /* CONFIG_CHIP_M32700_TS1 */ ); } static inline void _raw_write_unlock(rwlock_t *rw) { unsigned long tmp0, tmp1, tmp2; __asm__ __volatile__ ( "# write_unlock \n\t" "seth %1, #high(" RW_LOCK_BIAS_STR "); \n\t" "or3 %1, %1, #low(" RW_LOCK_BIAS_STR "); \n\t" "mvfc %2, psw; \n\t" "clrpsw #0x40 -> nop; \n\t" DCACHE_CLEAR("%0", "r7", "%3") "lock %0, @%3; \n\t" "add %0, %1; \n\t" "unlock %0, @%3; \n\t" "mvtc %2, psw; \n\t" : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2) : "r" (&rw->lock) : "memory" #ifdef CONFIG_CHIP_M32700_TS1 , "r7" #endif /* CONFIG_CHIP_M32700_TS1 */ ); } #define _raw_read_trylock(lock) generic_raw_read_trylock(lock) static inline int _raw_write_trylock(rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; if (atomic_sub_and_test(RW_LOCK_BIAS, count)) return 1; atomic_add(RW_LOCK_BIAS, count); return 0; } #endif /* _ASM_M32R_SPINLOCK_H */