diff options
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/Kconfig | 4 | ||||
| -rw-r--r-- | arch/ia64/include/asm/spinlock.h | 175 | ||||
| -rw-r--r-- | arch/ia64/include/asm/spinlock_types.h | 2 | ||||
| -rw-r--r-- | arch/ia64/kernel/head.S | 89 | ||||
| -rw-r--r-- | arch/ia64/kernel/ia64_ksyms.c | 20 | ||||
| -rw-r--r-- | arch/ia64/oprofile/backtrace.c | 20 |
6 files changed, 92 insertions, 218 deletions
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 6851e52ed5a..1ee596cd942 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -60,9 +60,7 @@ config IOMMU_HELPER bool config GENERIC_LOCKBREAK - bool - default y - depends on SMP && PREEMPT + def_bool n config RWSEM_XCHGADD_ALGORITHM bool diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h index 13ab71576bc..30bb930e111 100644 --- a/arch/ia64/include/asm/spinlock.h +++ b/arch/ia64/include/asm/spinlock.h @@ -19,103 +19,106 @@ #define __raw_spin_lock_init(x) ((x)->lock = 0) -#ifdef ASM_SUPPORTED /* - * Try to get the lock. If we fail to get the lock, make a non-standard call to - * ia64_spinlock_contention(). We do not use a normal call because that would force all - * callers of __raw_spin_lock() to be non-leaf routines. Instead, ia64_spinlock_contention() is - * carefully coded to touch only those registers that __raw_spin_lock() marks "clobbered". + * Ticket locks are conceptually two parts, one indicating the current head of + * the queue, and the other indicating the current tail. The lock is acquired + * by atomically noting the tail and incrementing it by one (thus adding + * ourself to the queue and noting our position), then waiting until the head + * becomes equal to the the initial value of the tail. + * + * 63 32 31 0 + * +----------------------------------------------------+ + * | next_ticket_number | now_serving | + * +----------------------------------------------------+ */ -#define IA64_SPINLOCK_CLOBBERS "ar.ccv", "ar.pfs", "p14", "p15", "r27", "r28", "r29", "r30", "b6", "memory" +#define TICKET_SHIFT 32 -static inline void -__raw_spin_lock_flags (raw_spinlock_t *lock, unsigned long flags) +static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) { - register volatile unsigned int *ptr asm ("r31") = &lock->lock; - -#if (__GNUC__ == 3 && __GNUC_MINOR__ < 3) -# ifdef CONFIG_ITANIUM - /* don't use brl on Itanium... */ - asm volatile ("{\n\t" - " mov ar.ccv = r0\n\t" - " mov r28 = ip\n\t" - " mov r30 = 1;;\n\t" - "}\n\t" - "cmpxchg4.acq r30 = [%1], r30, ar.ccv\n\t" - "movl r29 = ia64_spinlock_contention_pre3_4;;\n\t" - "cmp4.ne p14, p0 = r30, r0\n\t" - "mov b6 = r29;;\n\t" - "mov r27=%2\n\t" - "(p14) br.cond.spnt.many b6" - : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); -# else - asm volatile ("{\n\t" - " mov ar.ccv = r0\n\t" - " mov r28 = ip\n\t" - " mov r30 = 1;;\n\t" - "}\n\t" - "cmpxchg4.acq r30 = [%1], r30, ar.ccv;;\n\t" - "cmp4.ne p14, p0 = r30, r0\n\t" - "mov r27=%2\n\t" - "(p14) brl.cond.spnt.many ia64_spinlock_contention_pre3_4;;" - : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); -# endif /* CONFIG_MCKINLEY */ -#else -# ifdef CONFIG_ITANIUM - /* don't use brl on Itanium... */ - /* mis-declare, so we get the entry-point, not it's function descriptor: */ - asm volatile ("mov r30 = 1\n\t" - "mov r27=%2\n\t" - "mov ar.ccv = r0;;\n\t" - "cmpxchg4.acq r30 = [%0], r30, ar.ccv\n\t" - "movl r29 = ia64_spinlock_contention;;\n\t" - "cmp4.ne p14, p0 = r30, r0\n\t" - "mov b6 = r29;;\n\t" - "(p14) br.call.spnt.many b6 = b6" - : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); -# else - asm volatile ("mov r30 = 1\n\t" - "mov r27=%2\n\t" - "mov ar.ccv = r0;;\n\t" - "cmpxchg4.acq r30 = [%0], r30, ar.ccv;;\n\t" - "cmp4.ne p14, p0 = r30, r0\n\t" - "(p14) brl.call.spnt.many b6=ia64_spinlock_contention;;" - : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); -# endif /* CONFIG_MCKINLEY */ -#endif + int *p = (int *)&lock->lock, turn, now_serving; + + now_serving = *p; + turn = ia64_fetchadd(1, p+1, acq); + + if (turn == now_serving) + return; + + do { + cpu_relax(); + } while (ACCESS_ONCE(*p) != turn); } -#define __raw_spin_lock(lock) __raw_spin_lock_flags(lock, 0) +static __always_inline int __ticket_spin_trylock(raw_spinlock_t *lock) +{ + long tmp = ACCESS_ONCE(lock->lock), try; -/* Unlock by doing an ordered store and releasing the cacheline with nta */ -static inline void __raw_spin_unlock(raw_spinlock_t *x) { - barrier(); - asm volatile ("st4.rel.nta [%0] = r0\n\t" :: "r"(x)); + if (!(((tmp >> TICKET_SHIFT) ^ tmp) & ((1L << TICKET_SHIFT) - 1))) { + try = tmp + (1L << TICKET_SHIFT); + + return ia64_cmpxchg(acq, &lock->lock, tmp, try, sizeof (tmp)) == tmp; + } + return 0; } -#else /* !ASM_SUPPORTED */ -#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) -# define __raw_spin_lock(x) \ -do { \ - __u32 *ia64_spinlock_ptr = (__u32 *) (x); \ - __u64 ia64_spinlock_val; \ - ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0); \ - if (unlikely(ia64_spinlock_val)) { \ - do { \ - while (*ia64_spinlock_ptr) \ - ia64_barrier(); \ - ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0); \ - } while (ia64_spinlock_val); \ - } \ -} while (0) -#define __raw_spin_unlock(x) do { barrier(); ((raw_spinlock_t *) x)->lock = 0; } while (0) -#endif /* !ASM_SUPPORTED */ +static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock) +{ + int *p = (int *)&lock->lock; + + (void)ia64_fetchadd(1, p, rel); +} + +static inline int __ticket_spin_is_locked(raw_spinlock_t *lock) +{ + long tmp = ACCESS_ONCE(lock->lock); + + return !!(((tmp >> TICKET_SHIFT) ^ tmp) & ((1L << TICKET_SHIFT) - 1)); +} + +static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) +{ + long tmp = ACCESS_ONCE(lock->lock); -#define __raw_spin_is_locked(x) ((x)->lock != 0) -#define __raw_spin_trylock(x) (cmpxchg_acq(&(x)->lock, 0, 1) == 0) -#define __raw_spin_unlock_wait(lock) \ - do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) + return (((tmp >> TICKET_SHIFT) - tmp) & ((1L << TICKET_SHIFT) - 1)) > 1; +} + +static inline int __raw_spin_is_locked(raw_spinlock_t *lock) +{ + return __ticket_spin_is_locked(lock); +} + +static inline int __raw_spin_is_contended(raw_spinlock_t *lock) +{ + return __ticket_spin_is_contended(lock); +} +#define __raw_spin_is_contended __raw_spin_is_contended + +static __always_inline void __raw_spin_lock(raw_spinlock_t *lock) +{ + __ticket_spin_lock(lock); +} + +static __always_inline int __raw_spin_trylock(raw_spinlock_t *lock) +{ + return __ticket_spin_trylock(lock); +} + +static __always_inline void __raw_spin_unlock(raw_spinlock_t *lock) +{ + __ticket_spin_unlock(lock); +} + +static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock, + unsigned long flags) +{ + __raw_spin_lock(lock); +} + +static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock) +{ + while (__raw_spin_is_locked(lock)) + cpu_relax(); +} #define __raw_read_can_lock(rw) (*(volatile int *)(rw) >= 0) #define __raw_write_can_lock(rw) (*(volatile int *)(rw) == 0) diff --git a/arch/ia64/include/asm/spinlock_types.h b/arch/ia64/include/asm/spinlock_types.h index 474e46f1ab4..b61d136d9bc 100644 --- a/arch/ia64/include/asm/spinlock_types.h +++ b/arch/ia64/include/asm/spinlock_types.h @@ -6,7 +6,7 @@ #endif typedef struct { - volatile unsigned int lock; + volatile unsigned long lock; } raw_spinlock_t; #define __RAW_SPIN_LOCK_UNLOCKED { 0 } diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index 1a6e44515eb..696eff28a0c 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -1130,95 +1130,6 @@ SET_REG(b5); #endif /* CONFIG_IA64_BRL_EMU */ #ifdef CONFIG_SMP - /* - * This routine handles spinlock contention. It uses a non-standard calling - * convention to avoid converting leaf routines into interior routines. Because - * of this special convention, there are several restrictions: - * - * - do not use gp relative variables, this code is called from the kernel - * and from modules, r1 is undefined. - * - do not use stacked registers, the caller owns them. - * - do not use the scratch stack space, the caller owns it. - * - do not use any registers other than the ones listed below - * - * Inputs: - * ar.pfs - saved CFM of caller - * ar.ccv - 0 (and available for use) - * r27 - flags from spin_lock_irqsave or 0. Must be preserved. - * r28 - available for use. - * r29 - available for use. - * r30 - available for use. - * r31 - address of lock, available for use. - * b6 - return address - * p14 - available for use. - * p15 - used to track flag status. - * - * If you patch this code to use more registers, do not forget to update - * the clobber lists for spin_lock() in arch/ia64/include/asm/spinlock.h. - */ - -#if (__GNUC__ == 3 && __GNUC_MINOR__ < 3) - -GLOBAL_ENTRY(ia64_spinlock_contention_pre3_4) - .prologue - .save ar.pfs, r0 // this code effectively has a zero frame size - .save rp, r28 - .body - nop 0 - tbit.nz p15,p0=r27,IA64_PSR_I_BIT - .restore sp // pop existing prologue after next insn - mov b6 = r28 - .prologue - .save ar.pfs, r0 - .altrp b6 - .body - ;; -(p15) ssm psr.i // reenable interrupts if they were on - // DavidM says that srlz.d is slow and is not required in this case -.wait: - // exponential backoff, kdb, lockmeter etc. go in here - hint @pause - ld4 r30=[r31] // don't use ld4.bias; if it's contended, we won't write the word - nop 0 - ;; - cmp4.ne p14,p0=r30,r0 -(p14) br.cond.sptk.few .wait -(p15) rsm psr.i // disable interrupts if we reenabled them - br.cond.sptk.few b6 // lock is now free, try to acquire - .global ia64_spinlock_contention_pre3_4_end // for kernprof -ia64_spinlock_contention_pre3_4_end: -END(ia64_spinlock_contention_pre3_4) - -#else - -GLOBAL_ENTRY(ia64_spinlock_contention) - .prologue - .altrp b6 - .body - tbit.nz p15,p0=r27,IA64_PSR_I_BIT - ;; -.wait: -(p15) ssm psr.i // reenable interrupts if they were on - // DavidM says that srlz.d is slow and is not required in this case -.wait2: - // exponential backoff, kdb, lockmeter etc. go in here - hint @pause - ld4 r30=[r31] // don't use ld4.bias; if it's contended, we won't write the word - ;; - cmp4.ne p14,p0=r30,r0 - mov r30 = 1 -(p14) br.cond.sptk.few .wait2 -(p15) rsm psr.i // disable interrupts if we reenabled them - ;; - cmpxchg4.acq r30=[r31], r30, ar.ccv - ;; - cmp4.ne p14,p0=r0,r30 -(p14) br.cond.sptk.few .wait - - br.ret.sptk.many b6 // lock is now taken -END(ia64_spinlock_contention) - -#endif #ifdef CONFIG_HOTPLUG_CPU GLOBAL_ENTRY(ia64_jump_to_sal) diff --git a/arch/ia64/kernel/ia64_ksyms.c b/arch/ia64/kernel/ia64_ksyms.c index 8ebccb589e1..14d39e30062 100644 --- a/arch/ia64/kernel/ia64_ksyms.c +++ b/arch/ia64/kernel/ia64_ksyms.c @@ -84,26 +84,6 @@ EXPORT_SYMBOL(ia64_save_scratch_fpregs); #include <asm/unwind.h> EXPORT_SYMBOL(unw_init_running); -#ifdef ASM_SUPPORTED -# ifdef CONFIG_SMP -# if (__GNUC__ == 3 && __GNUC_MINOR__ < 3) -/* - * This is not a normal routine and we don't want a function descriptor for it, so we use - * a fake declaration here. - */ -extern char ia64_spinlock_contention_pre3_4; -EXPORT_SYMBOL(ia64_spinlock_contention_pre3_4); -# else -/* - * This is not a normal routine and we don't want a function descriptor for it, so we use - * a fake declaration here. - */ -extern char ia64_spinlock_contention; -EXPORT_SYMBOL(ia64_spinlock_contention); -# endif -# endif -#endif - #if defined(CONFIG_IA64_ESI) || defined(CONFIG_IA64_ESI_MODULE) extern void esi_call_phys (void); EXPORT_SYMBOL_GPL(esi_call_phys); diff --git a/arch/ia64/oprofile/backtrace.c b/arch/ia64/oprofile/backtrace.c index adb01566bd5..5cdd7e4a597 100644 --- a/arch/ia64/oprofile/backtrace.c +++ b/arch/ia64/oprofile/backtrace.c @@ -32,24 +32,6 @@ typedef struct u64 *prev_pfs_loc; /* state for WAR for old spinlock ool code */ } ia64_backtrace_t; -#if (__GNUC__ == 3 && __GNUC_MINOR__ < 3) -/* - * Returns non-zero if the PC is in the spinlock contention out-of-line code - * with non-standard calling sequence (on older compilers). - */ -static __inline__ int in_old_ool_spinlock_code(unsigned long pc) -{ - extern const char ia64_spinlock_contention_pre3_4[] __attribute__ ((weak)); - extern const char ia64_spinlock_contention_pre3_4_end[] __attribute__ ((weak)); - unsigned long sc_start = (unsigned long)ia64_spinlock_contention_pre3_4; - unsigned long sc_end = (unsigned long)ia64_spinlock_contention_pre3_4_end; - return (sc_start && sc_end && pc >= sc_start && pc < sc_end); -} -#else -/* Newer spinlock code does a proper br.call and works fine with the unwinder */ -#define in_old_ool_spinlock_code(pc) 0 -#endif - /* Returns non-zero if the PC is in the Interrupt Vector Table */ static __inline__ int in_ivt_code(unsigned long pc) { @@ -80,7 +62,7 @@ static __inline__ int next_frame(ia64_backtrace_t *bt) */ if (bt->prev_pfs_loc && bt->regs && bt->frame.pfs_loc == bt->prev_pfs_loc) bt->frame.pfs_loc = &bt->regs->ar_pfs; - bt->prev_pfs_loc = (in_old_ool_spinlock_code(bt->frame.ip) ? bt->frame.pfs_loc : NULL); + bt->prev_pfs_loc = NULL; return unw_unwind(&bt->frame) == 0; } |