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Diffstat (limited to 'include/asm-sparc64/spinlock.h')
| -rw-r--r-- | include/asm-sparc64/spinlock.h | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/include/asm-sparc64/spinlock.h b/include/asm-sparc64/spinlock.h new file mode 100644 index 000000000000..11efa474865b --- /dev/null +++ b/include/asm-sparc64/spinlock.h @@ -0,0 +1,310 @@ +/* spinlock.h: 64-bit Sparc spinlock support. + * + * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) + */ + +#ifndef __SPARC64_SPINLOCK_H +#define __SPARC64_SPINLOCK_H + +#include <linux/config.h> +#include <linux/threads.h> /* For NR_CPUS */ + +#ifndef __ASSEMBLY__ + +/* To get debugging spinlocks which detect and catch + * deadlock situations, set CONFIG_DEBUG_SPINLOCK + * and rebuild your kernel. + */ + +/* All of these locking primitives are expected to work properly + * even in an RMO memory model, which currently is what the kernel + * runs in. + * + * There is another issue. Because we play games to save cycles + * in the non-contention case, we need to be extra careful about + * branch targets into the "spinning" code. They live in their + * own section, but the newer V9 branches have a shorter range + * than the traditional 32-bit sparc branch variants. The rule + * is that the branches that go into and out of the spinner sections + * must be pre-V9 branches. + */ + +#ifndef CONFIG_DEBUG_SPINLOCK + +typedef unsigned char spinlock_t; +#define SPIN_LOCK_UNLOCKED 0 + +#define spin_lock_init(lock) (*((unsigned char *)(lock)) = 0) +#define spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) + +#define spin_unlock_wait(lock) \ +do { membar("#LoadLoad"); \ +} while(*((volatile unsigned char *)lock)) + +static inline void _raw_spin_lock(spinlock_t *lock) +{ + unsigned long tmp; + + __asm__ __volatile__( +"1: ldstub [%1], %0\n" +" brnz,pn %0, 2f\n" +" membar #StoreLoad | #StoreStore\n" +" .subsection 2\n" +"2: ldub [%1], %0\n" +" brnz,pt %0, 2b\n" +" membar #LoadLoad\n" +" ba,a,pt %%xcc, 1b\n" +" .previous" + : "=&r" (tmp) + : "r" (lock) + : "memory"); +} + +static inline int _raw_spin_trylock(spinlock_t *lock) +{ + unsigned long result; + + __asm__ __volatile__( +" ldstub [%1], %0\n" +" membar #StoreLoad | #StoreStore" + : "=r" (result) + : "r" (lock) + : "memory"); + + return (result == 0UL); +} + +static inline void _raw_spin_unlock(spinlock_t *lock) +{ + __asm__ __volatile__( +" membar #StoreStore | #LoadStore\n" +" stb %%g0, [%0]" + : /* No outputs */ + : "r" (lock) + : "memory"); +} + +static inline void _raw_spin_lock_flags(spinlock_t *lock, unsigned long flags) +{ + unsigned long tmp1, tmp2; + + __asm__ __volatile__( +"1: ldstub [%2], %0\n" +" brnz,pn %0, 2f\n" +" membar #StoreLoad | #StoreStore\n" +" .subsection 2\n" +"2: rdpr %%pil, %1\n" +" wrpr %3, %%pil\n" +"3: ldub [%2], %0\n" +" brnz,pt %0, 3b\n" +" membar #LoadLoad\n" +" ba,pt %%xcc, 1b\n" +" wrpr %1, %%pil\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r"(lock), "r"(flags) + : "memory"); +} + +#else /* !(CONFIG_DEBUG_SPINLOCK) */ + +typedef struct { + unsigned char lock; + unsigned int owner_pc, owner_cpu; +} spinlock_t; +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0xff } +#define spin_lock_init(__lock) \ +do { (__lock)->lock = 0; \ + (__lock)->owner_pc = 0; \ + (__lock)->owner_cpu = 0xff; \ +} while(0) +#define spin_is_locked(__lock) (*((volatile unsigned char *)(&((__lock)->lock))) != 0) +#define spin_unlock_wait(__lock) \ +do { \ + membar("#LoadLoad"); \ +} while(*((volatile unsigned char *)(&((__lock)->lock)))) + +extern void _do_spin_lock (spinlock_t *lock, char *str); +extern void _do_spin_unlock (spinlock_t *lock); +extern int _do_spin_trylock (spinlock_t *lock); + +#define _raw_spin_trylock(lp) _do_spin_trylock(lp) +#define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_lock") +#define _raw_spin_unlock(lock) _do_spin_unlock(lock) +#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) + +#endif /* CONFIG_DEBUG_SPINLOCK */ + +/* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */ + +#ifndef CONFIG_DEBUG_SPINLOCK + +typedef unsigned int rwlock_t; +#define RW_LOCK_UNLOCKED 0 +#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) + +static void inline __read_lock(rwlock_t *lock) +{ + unsigned long tmp1, tmp2; + + __asm__ __volatile__ ( +"1: ldsw [%2], %0\n" +" brlz,pn %0, 2f\n" +"4: add %0, 1, %1\n" +" cas [%2], %0, %1\n" +" cmp %0, %1\n" +" bne,pn %%icc, 1b\n" +" membar #StoreLoad | #StoreStore\n" +" .subsection 2\n" +"2: ldsw [%2], %0\n" +" brlz,pt %0, 2b\n" +" membar #LoadLoad\n" +" ba,a,pt %%xcc, 4b\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock) + : "memory"); +} + +static void inline __read_unlock(rwlock_t *lock) +{ + unsigned long tmp1, tmp2; + + __asm__ __volatile__( +" membar #StoreLoad | #LoadLoad\n" +"1: lduw [%2], %0\n" +" sub %0, 1, %1\n" +" cas [%2], %0, %1\n" +" cmp %0, %1\n" +" bne,pn %%xcc, 1b\n" +" nop" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock) + : "memory"); +} + +static void inline __write_lock(rwlock_t *lock) +{ + unsigned long mask, tmp1, tmp2; + + mask = 0x80000000UL; + + __asm__ __volatile__( +"1: lduw [%2], %0\n" +" brnz,pn %0, 2f\n" +"4: or %0, %3, %1\n" +" cas [%2], %0, %1\n" +" cmp %0, %1\n" +" bne,pn %%icc, 1b\n" +" membar #StoreLoad | #StoreStore\n" +" .subsection 2\n" +"2: lduw [%2], %0\n" +" brnz,pt %0, 2b\n" +" membar #LoadLoad\n" +" ba,a,pt %%xcc, 4b\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock), "r" (mask) + : "memory"); +} + +static void inline __write_unlock(rwlock_t *lock) +{ + __asm__ __volatile__( +" membar #LoadStore | #StoreStore\n" +" stw %%g0, [%0]" + : /* no outputs */ + : "r" (lock) + : "memory"); +} + +static int inline __write_trylock(rwlock_t *lock) +{ + unsigned long mask, tmp1, tmp2, result; + + mask = 0x80000000UL; + + __asm__ __volatile__( +" mov 0, %2\n" +"1: lduw [%3], %0\n" +" brnz,pn %0, 2f\n" +" or %0, %4, %1\n" +" cas [%3], %0, %1\n" +" cmp %0, %1\n" +" bne,pn %%icc, 1b\n" +" membar #StoreLoad | #StoreStore\n" +" mov 1, %2\n" +"2:" + : "=&r" (tmp1), "=&r" (tmp2), "=&r" (result) + : "r" (lock), "r" (mask) + : "memory"); + + return result; +} + +#define _raw_read_lock(p) __read_lock(p) +#define _raw_read_unlock(p) __read_unlock(p) +#define _raw_write_lock(p) __write_lock(p) +#define _raw_write_unlock(p) __write_unlock(p) +#define _raw_write_trylock(p) __write_trylock(p) + +#else /* !(CONFIG_DEBUG_SPINLOCK) */ + +typedef struct { + unsigned long lock; + unsigned int writer_pc, writer_cpu; + unsigned int reader_pc[NR_CPUS]; +} rwlock_t; +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0xff, { } } +#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) + +extern void _do_read_lock(rwlock_t *rw, char *str); +extern void _do_read_unlock(rwlock_t *rw, char *str); +extern void _do_write_lock(rwlock_t *rw, char *str); +extern void _do_write_unlock(rwlock_t *rw); +extern int _do_write_trylock(rwlock_t *rw, char *str); + +#define _raw_read_lock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_read_lock(lock, "read_lock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_read_unlock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_read_unlock(lock, "read_unlock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_write_lock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_write_lock(lock, "write_lock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_write_unlock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_write_unlock(lock); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_write_trylock(lock) \ +({ unsigned long flags; \ + int val; \ + local_irq_save(flags); \ + val = _do_write_trylock(lock, "write_trylock"); \ + local_irq_restore(flags); \ + val; \ +}) + +#endif /* CONFIG_DEBUG_SPINLOCK */ + +#define _raw_read_trylock(lock) generic_raw_read_trylock(lock) + +#endif /* !(__ASSEMBLY__) */ + +#endif /* !(__SPARC64_SPINLOCK_H) */ |
