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- /* 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
-
- #ifndef __ASSEMBLY__
-
- #ifndef __SMP__
-
- typedef unsigned char spinlock_t;
- #define SPIN_LOCK_UNLOCKED 0
-
- #define spin_lock_init(lock) do { } while(0)
- #define spin_lock(lock) do { } while(0)
- #define spin_trylock(lock) do { } while(0)
- #define spin_unlock_wait(lock) do { } while(0)
- #define spin_unlock(lock) do { } while(0)
- #define spin_lock_irq(lock) cli()
- #define spin_unlock_irq(lock) sti()
-
- #define spin_lock_irqsave(lock, flags) save_and_cli(flags)
- #define spin_unlock_irqrestore(lock, flags) restore_flags(flags)
-
- /*
- * 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 unsigned long rwlock_t;
- #define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
-
- #define read_lock(lock) do { } while(0)
- #define read_unlock(lock) do { } while(0)
- #define write_lock(lock) do { } while(0)
- #define write_unlock(lock) do { } while(0)
- #define read_lock_irq(lock) cli()
- #define read_unlock_irq(lock) sti()
- #define write_lock_irq(lock) cli()
- #define write_unlock_irq(lock) sti()
-
- #define read_lock_irqsave(lock, flags) save_and_cli(flags)
- #define read_unlock_irqrestore(lock, flags) restore_flags(flags)
- #define write_lock_irqsave(lock, flags) save_and_cli(flags)
- #define write_unlock_irqrestore(lock, flags) restore_flags(flags)
-
- #else /* !(__SMP__) */
-
- /* To get debugging spinlocks which detect and catch
- * deadlock situations, set DEBUG_SPINLOCKS in the sparc64
- * specific makefile 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 SPIN_LOCK_DEBUG
-
- 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))
-
- extern __inline__ void spin_lock(spinlock_t *lock)
- {
- __asm__ __volatile__("
- 1: ldstub [%0], %%g7
- brnz,pn %%g7, 2f
- membar #StoreLoad | #StoreStore
- .subsection 2
- 2: ldub [%0], %%g7
- brnz,pt %%g7, 2b
- membar #LoadLoad
- b,a,pt %%xcc, 1b
- .previous
- " : /* no outputs */
- : "r" (lock)
- : "g7", "memory");
- }
-
- extern __inline__ int spin_trylock(spinlock_t *lock)
- {
- unsigned int result;
- __asm__ __volatile__("ldstub [%1], %0\n\t"
- "membar #StoreLoad | #StoreStore"
- : "=r" (result)
- : "r" (lock)
- : "memory");
- return (result == 0);
- }
-
- extern __inline__ void spin_unlock(spinlock_t *lock)
- {
- __asm__ __volatile__("membar #StoreStore | #LoadStore\n\t"
- "stb %%g0, [%0]\n\t"
- : /* No outputs */
- : "r" (lock)
- : "memory");
- }
-
- extern __inline__ void spin_lock_irq(spinlock_t *lock)
- {
- __asm__ __volatile__("
- wrpr %%g0, 15, %%pil
- 1: ldstub [%0], %%g7
- brnz,pn %%g7, 2f
- membar #StoreLoad | #StoreStore
- .subsection 2
- 2: ldub [%0], %%g7
- brnz,pt %%g7, 2b
- membar #LoadLoad
- b,a,pt %%xcc, 1b
- .previous
- " : /* no outputs */
- : "r" (lock)
- : "g7", "memory");
- }
-
- extern __inline__ void spin_unlock_irq(spinlock_t *lock)
- {
- __asm__ __volatile__("
- membar #StoreStore | #LoadStore
- stb %%g0, [%0]
- wrpr %%g0, 0x0, %%pil
- " : /* no outputs */
- : "r" (lock)
- : "memory");
- }
-
- #define spin_lock_irqsave(__lock, flags) \
- do { register spinlock_t *__lp asm("g1"); \
- __lp = (__lock); \
- __asm__ __volatile__( \
- "\n rdpr %%pil, %0\n" \
- " wrpr %%g0, 15, %%pil\n" \
- "1: ldstub [%1], %%g7\n" \
- " brnz,pn %%g7, 2f\n" \
- " membar #StoreLoad | #StoreStore\n" \
- " .subsection 2\n" \
- "2: ldub [%1], %%g7\n" \
- " brnz,pt %%g7, 2b\n" \
- " membar #LoadLoad\n" \
- " b,a,pt %%xcc, 1b\n" \
- " .previous\n" \
- : "=&r" (flags) \
- : "r" (__lp) \
- : "g7", "memory"); \
- } while(0)
-
- extern __inline__ void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
- {
- __asm__ __volatile__("
- membar #StoreStore | #LoadStore
- stb %%g0, [%0]
- wrpr %1, 0x0, %%pil
- " : /* no outputs */
- : "r" (lock), "r" (flags)
- : "memory");
- }
-
- #else /* !(SPIN_LOCK_DEBUG) */
-
- typedef struct {
- unsigned char lock;
- unsigned int owner_pc, owner_cpu;
- } spinlock_t;
- #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, NO_PROC_ID }
- #define spin_lock_init(__lock) \
- do { (__lock)->lock = 0; \
- (__lock)->owner_pc = 0; \
- (__lock)->owner_cpu = NO_PROC_ID; \
- } 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 _spin_trylock (spinlock_t *lock);
-
- #define spin_trylock(lp) _spin_trylock(lp)
- #define spin_lock(lock) _do_spin_lock(lock, "spin_lock")
- #define spin_lock_irq(lock) do { __cli(); _do_spin_lock(lock, "spin_lock_irq"); } while(0)
- #define spin_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_spin_lock(lock, "spin_lock_irqsave"); } while(0)
- #define spin_unlock(lock) _do_spin_unlock(lock)
- #define spin_unlock_irq(lock) do { _do_spin_unlock(lock); __sti(); } while(0)
- #define spin_unlock_irqrestore(lock, flags) do { _do_spin_unlock(lock); __restore_flags(flags); } while(0)
-
- #endif /* SPIN_LOCK_DEBUG */
-
- /* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */
-
- #ifndef SPIN_LOCK_DEBUG
-
- typedef unsigned long rwlock_t;
- #define RW_LOCK_UNLOCKED 0
-
- extern __inline__ void read_lock(rwlock_t *rw)
- {
- __asm__ __volatile__("
- 1: ldx [%0], %%g5
- brlz,pn %%g5, 2f
- 4: add %%g5, 1, %%g7
- casx [%0], %%g5, %%g7
- cmp %%g5, %%g7
- bne,pn %%xcc, 1b
- membar #StoreLoad | #StoreStore
- .subsection 2
- 2: ldx [%0], %%g5
- brlz,pt %%g5, 2b
- membar #LoadLoad
- b,a,pt %%xcc, 4b
- .previous
- " : /* no outputs */
- : "r" (rw)
- : "g5", "g7", "cc", "memory");
- }
-
- extern __inline__ void read_unlock(rwlock_t *rw)
- {
- __asm__ __volatile__("
- 1: ldx [%0], %%g5
- sub %%g5, 1, %%g7
- casx [%0], %%g5, %%g7
- cmp %%g5, %%g7
- bne,pn %%xcc, 1b
- membar #StoreLoad | #StoreStore
- " : /* no outputs */
- : "r" (rw)
- : "g5", "g7", "cc", "memory");
- }
-
- extern __inline__ void write_lock(rwlock_t *rw)
- {
- __asm__ __volatile__("
- sethi %%uhi(0x8000000000000000), %%g3
- sllx %%g3, 32, %%g3
- 1: ldx [%0], %%g5
- brlz,pn %%g5, 5f
- 4: or %%g5, %%g3, %%g7
- casx [%0], %%g5, %%g7
- cmp %%g5, %%g7
- bne,pn %%xcc, 1b
- andncc %%g7, %%g3, %%g0
- bne,pn %%xcc, 7f
- membar #StoreLoad | #StoreStore
- .subsection 2
- 7: ldx [%0], %%g5
- andn %%g5, %%g3, %%g7
- casx [%0], %%g5, %%g7
- cmp %%g5, %%g7
- bne,pn %%xcc, 7b
- membar #StoreLoad | #StoreStore
- 5: ldx [%0], %%g5
- brnz,pt %%g5, 5b
- membar #LoadLoad
- b,a,pt %%xcc, 4b
- .previous
- " : /* no outputs */
- : "r" (rw)
- : "g3", "g5", "g7", "memory", "cc");
- }
-
- extern __inline__ void write_unlock(rwlock_t *rw)
- {
- __asm__ __volatile__("
- sethi %%uhi(0x8000000000000000), %%g3
- sllx %%g3, 32, %%g3
- 1: ldx [%0], %%g5
- andn %%g5, %%g3, %%g7
- casx [%0], %%g5, %%g7
- cmp %%g5, %%g7
- bne,pn %%xcc, 1b
- membar #StoreLoad | #StoreStore
- " : /* no outputs */
- : "r" (rw)
- : "g3", "g5", "g7", "memory", "cc");
- }
-
- #define read_lock_irq(lock) do { __cli(); read_lock(lock); } while (0)
- #define read_unlock_irq(lock) do { read_unlock(lock); __sti(); } while (0)
- #define write_lock_irq(lock) do { __cli(); write_lock(lock); } while (0)
- #define write_unlock_irq(lock) do { write_unlock(lock); __sti(); } while (0)
-
- #define read_lock_irqsave(lock, flags) \
- do { __save_and_cli(flags); read_lock(lock); } while (0)
- #define read_unlock_irqrestore(lock, flags) \
- do { read_unlock(lock); __restore_flags(flags); } while (0)
- #define write_lock_irqsave(lock, flags) \
- do { __save_and_cli(flags); write_lock(lock); } while (0)
- #define write_unlock_irqrestore(lock, flags) \
- do { write_unlock(lock); __restore_flags(flags); } while (0)
-
- #else /* !(SPIN_LOCK_DEBUG) */
-
- typedef struct {
- unsigned long lock;
- unsigned int writer_pc, writer_cpu;
- unsigned int reader_pc[4];
- } rwlock_t;
- #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, NO_PROC_ID, { 0, 0, 0, 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);
-
- #define read_lock(lock) \
- do { unsigned long flags; \
- __save_and_cli(flags); \
- _do_read_lock(lock, "read_lock"); \
- __restore_flags(flags); \
- } while(0)
- #define read_lock_irq(lock) do { __cli(); _do_read_lock(lock, "read_lock_irq"); } while(0)
- #define read_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_read_lock(lock, "read_lock_irqsave"); } while(0)
-
- #define read_unlock(lock) \
- do { unsigned long flags; \
- __save_and_cli(flags); \
- _do_read_unlock(lock, "read_unlock"); \
- __restore_flags(flags); \
- } while(0)
- #define read_unlock_irq(lock) do { _do_read_unlock(lock, "read_unlock_irq"); __sti() } while(0)
- #define read_unlock_irqrestore(lock, flags) do { _do_read_unlock(lock, "read_unlock_irqrestore"); __restore_flags(flags); } while(0)
-
- #define write_lock(lock) \
- do { unsigned long flags; \
- __save_and_cli(flags); \
- _do_write_lock(lock, "write_lock"); \
- __restore_flags(flags); \
- } while(0)
- #define write_lock_irq(lock) do { __cli(); _do_write_lock(lock, "write_lock_irq"); } while(0)
- #define write_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_write_lock(lock, "write_lock_irqsave"); } while(0)
-
- #define write_unlock(lock) \
- do { unsigned long flags; \
- __save_and_cli(flags); \
- _do_write_unlock(lock); \
- __restore_flags(flags); \
- } while(0)
- #define write_unlock_irq(lock) do { _do_write_unlock(lock); __sti(); } while(0)
- #define write_unlock_irqrestore(lock, flags) do { _do_write_unlock(lock); __restore_flags(flags); } while(0)
-
- #endif /* SPIN_LOCK_DEBUG */
-
- #endif /* __SMP__ */
-
- #endif /* !(__ASSEMBLY__) */
-
- #endif /* !(__SPARC64_SPIN%0_H) */
-