diff options
| -rw-r--r-- | arch/sparc/kernel/sparc_ksyms.c | 4 | ||||
| -rw-r--r-- | arch/sparc/lib/locks.S | 20 | ||||
| -rw-r--r-- | include/asm-sparc/spinlock.h | 28 |
3 files changed, 50 insertions, 2 deletions
diff --git a/arch/sparc/kernel/sparc_ksyms.c b/arch/sparc/kernel/sparc_ksyms.c index 4d441a554d3..33dadd9f287 100644 --- a/arch/sparc/kernel/sparc_ksyms.c +++ b/arch/sparc/kernel/sparc_ksyms.c @@ -87,6 +87,7 @@ extern void ___set_bit(void); extern void ___clear_bit(void); extern void ___change_bit(void); extern void ___rw_read_enter(void); +extern void ___rw_read_try(void); extern void ___rw_read_exit(void); extern void ___rw_write_enter(void); @@ -104,8 +105,9 @@ extern unsigned _Urem(unsigned, unsigned); EXPORT_SYMBOL(sparc_cpu_model); EXPORT_SYMBOL(kernel_thread); #ifdef CONFIG_SMP -// XXX find what uses (or used) these. +// XXX find what uses (or used) these. AV: see asm/spinlock.h EXPORT_SYMBOL(___rw_read_enter); +EXPORT_SYMBOL(___rw_read_try); EXPORT_SYMBOL(___rw_read_exit); EXPORT_SYMBOL(___rw_write_enter); #endif diff --git a/arch/sparc/lib/locks.S b/arch/sparc/lib/locks.S index 95fa4842496..b1df55cb221 100644 --- a/arch/sparc/lib/locks.S +++ b/arch/sparc/lib/locks.S @@ -25,6 +25,15 @@ ___rw_read_enter_spin_on_wlock: ldstub [%g1 + 3], %g2 b ___rw_read_enter_spin_on_wlock ldub [%g1 + 3], %g2 +___rw_read_try_spin_on_wlock: + andcc %g2, 0xff, %g0 + be,a ___rw_read_try + ldstub [%g1 + 3], %g2 + xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */ + bne,a ___rw_read_enter_spin_on_wlock + ld [%g1], %g2 + retl + mov %g4, %o7 ___rw_read_exit_spin_on_wlock: orcc %g2, 0x0, %g0 be,a ___rw_read_exit @@ -60,6 +69,17 @@ ___rw_read_exit: retl mov %g4, %o7 + .globl ___rw_read_try +___rw_read_try: + orcc %g2, 0x0, %g0 + bne ___rw_read_try_spin_on_wlock + ld [%g1], %g2 + add %g2, 1, %g2 + st %g2, [%g1] + set 1, %o1 + retl + mov %g4, %o7 + .globl ___rw_write_enter ___rw_write_enter: orcc %g2, 0x0, %g0 diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h index 557d08959d2..de2249b267c 100644 --- a/include/asm-sparc/spinlock.h +++ b/include/asm-sparc/spinlock.h @@ -129,6 +129,7 @@ static inline void __raw_write_lock(raw_rwlock_t *rw) : /* no outputs */ : "r" (lp) : "g2", "g4", "memory", "cc"); + *(volatile __u32 *)&lp->lock = ~0U; } static inline int __raw_write_trylock(raw_rwlock_t *rw) @@ -144,15 +145,40 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw) val = rw->lock & ~0xff; if (val) ((volatile u8*)&rw->lock)[3] = 0; + else + *(volatile u32*)&rw->lock = ~0U; } return (val == 0); } +static inline int __read_trylock(raw_rwlock_t *rw) +{ + register raw_rwlock_t *lp asm("g1"); + register int res asm("o0"); + lp = rw; + __asm__ __volatile__( + "mov %%o7, %%g4\n\t" + "call ___rw_read_try\n\t" + " ldstub [%%g1 + 3], %%g2\n" + : "=r" (res) + : "r" (lp) + : "g2", "g4", "memory", "cc"); + return res; +} + +#define __raw_read_trylock(lock) \ +({ unsigned long flags; \ + int res; \ + local_irq_save(flags); \ + res = __read_trylock(lock); \ + local_irq_restore(flags); \ + res; \ +}) + #define __raw_write_unlock(rw) do { (rw)->lock = 0; } while(0) #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) -#define __raw_read_trylock(lock) generic__raw_read_trylock(lock) #define _raw_spin_relax(lock) cpu_relax() #define _raw_read_relax(lock) cpu_relax() |