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Diffstat (limited to 'include/asm-sparc/spinlock_64.h')
| -rw-r--r-- | include/asm-sparc/spinlock_64.h | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/include/asm-sparc/spinlock_64.h b/include/asm-sparc/spinlock_64.h new file mode 100644 index 0000000..0006fe9 --- /dev/null +++ b/include/asm-sparc/spinlock_64.h @@ -0,0 +1,250 @@ +/* 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/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. + */ + +#define __raw_spin_is_locked(lp) ((lp)->lock != 0) + +#define __raw_spin_unlock_wait(lp) \ + do { rmb(); \ + } while((lp)->lock) + +static inline void __raw_spin_lock(raw_spinlock_t *lock) +{ + unsigned long tmp; + + __asm__ __volatile__( +"1: ldstub [%1], %0\n" +" membar #StoreLoad | #StoreStore\n" +" brnz,pn %0, 2f\n" +" nop\n" +" .subsection 2\n" +"2: ldub [%1], %0\n" +" membar #LoadLoad\n" +" brnz,pt %0, 2b\n" +" nop\n" +" ba,a,pt %%xcc, 1b\n" +" .previous" + : "=&r" (tmp) + : "r" (lock) + : "memory"); +} + +static inline int __raw_spin_trylock(raw_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(raw_spinlock_t *lock) +{ + __asm__ __volatile__( +" membar #StoreStore | #LoadStore\n" +" stb %%g0, [%0]" + : /* No outputs */ + : "r" (lock) + : "memory"); +} + +static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) +{ + unsigned long tmp1, tmp2; + + __asm__ __volatile__( +"1: ldstub [%2], %0\n" +" membar #StoreLoad | #StoreStore\n" +" brnz,pn %0, 2f\n" +" nop\n" +" .subsection 2\n" +"2: rdpr %%pil, %1\n" +" wrpr %3, %%pil\n" +"3: ldub [%2], %0\n" +" membar #LoadLoad\n" +" brnz,pt %0, 3b\n" +" nop\n" +" ba,pt %%xcc, 1b\n" +" wrpr %1, %%pil\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r"(lock), "r"(flags) + : "memory"); +} + +/* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */ + +static void inline __read_lock(raw_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" +" membar #StoreLoad | #StoreStore\n" +" bne,pn %%icc, 1b\n" +" nop\n" +" .subsection 2\n" +"2: ldsw [%2], %0\n" +" membar #LoadLoad\n" +" brlz,pt %0, 2b\n" +" nop\n" +" ba,a,pt %%xcc, 4b\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock) + : "memory"); +} + +static int inline __read_trylock(raw_rwlock_t *lock) +{ + int tmp1, tmp2; + + __asm__ __volatile__ ( +"1: ldsw [%2], %0\n" +" brlz,a,pn %0, 2f\n" +" mov 0, %0\n" +" add %0, 1, %1\n" +" cas [%2], %0, %1\n" +" cmp %0, %1\n" +" membar #StoreLoad | #StoreStore\n" +" bne,pn %%icc, 1b\n" +" mov 1, %0\n" +"2:" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock) + : "memory"); + + return tmp1; +} + +static void inline __read_unlock(raw_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(raw_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" +" membar #StoreLoad | #StoreStore\n" +" bne,pn %%icc, 1b\n" +" nop\n" +" .subsection 2\n" +"2: lduw [%2], %0\n" +" membar #LoadLoad\n" +" brnz,pt %0, 2b\n" +" nop\n" +" ba,a,pt %%xcc, 4b\n" +" .previous" + : "=&r" (tmp1), "=&r" (tmp2) + : "r" (lock), "r" (mask) + : "memory"); +} + +static void inline __write_unlock(raw_rwlock_t *lock) +{ + __asm__ __volatile__( +" membar #LoadStore | #StoreStore\n" +" stw %%g0, [%0]" + : /* no outputs */ + : "r" (lock) + : "memory"); +} + +static int inline __write_trylock(raw_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" +" membar #StoreLoad | #StoreStore\n" +" bne,pn %%icc, 1b\n" +" nop\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_trylock(p) __read_trylock(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) + +#define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL)) +#define __raw_write_can_lock(rw) (!(rw)->lock) + +#define _raw_spin_relax(lock) cpu_relax() +#define _raw_read_relax(lock) cpu_relax() +#define _raw_write_relax(lock) cpu_relax() + +#endif /* !(__ASSEMBLY__) */ + +#endif /* !(__SPARC64_SPINLOCK_H) */ |
