diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/parisc/include/asm/spinlock.h | 160 | ||||
| -rw-r--r-- | arch/parisc/include/asm/spinlock_types.h | 14 | ||||
| -rw-r--r-- | arch/parisc/kernel/alternative.c | 37 | ||||
| -rw-r--r-- | arch/parisc/kernel/irq.c | 22 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 2 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscalls/syscalltbl.sh | 4 |
6 files changed, 112 insertions, 127 deletions
diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h index 197d2247e4db..70fecb8dc4e2 100644 --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -10,25 +10,34 @@ static inline int arch_spin_is_locked(arch_spinlock_t *x) { volatile unsigned int *a = __ldcw_align(x); + smp_mb(); return *a == 0; } -#define arch_spin_lock(lock) arch_spin_lock_flags(lock, 0) +static inline void arch_spin_lock(arch_spinlock_t *x) +{ + volatile unsigned int *a; + + a = __ldcw_align(x); + while (__ldcw(a) == 0) + while (*a == 0) + cpu_relax(); +} static inline void arch_spin_lock_flags(arch_spinlock_t *x, unsigned long flags) { volatile unsigned int *a; + unsigned long flags_dis; a = __ldcw_align(x); - while (__ldcw(a) == 0) + while (__ldcw(a) == 0) { + local_save_flags(flags_dis); + local_irq_restore(flags); while (*a == 0) - if (flags & PSW_SM_I) { - local_irq_enable(); - cpu_relax(); - local_irq_disable(); - } else - cpu_relax(); + cpu_relax(); + local_irq_restore(flags_dis); + } } #define arch_spin_lock_flags arch_spin_lock_flags @@ -58,116 +67,93 @@ static inline int arch_spin_trylock(arch_spinlock_t *x) /* * Read-write spinlocks, allowing multiple readers but only one writer. - * Linux rwlocks are unfair to writers; they can be starved for an indefinite - * time by readers. With care, they can also be taken in interrupt context. + * Unfair locking as Writers could be starved indefinitely by Reader(s) * - * In the PA-RISC implementation, we have a spinlock and a counter. - * Readers use the lock to serialise their access to the counter (which - * records how many readers currently hold the lock). - * Writers hold the spinlock, preventing any readers or other writers from - * grabbing the rwlock. + * The spinlock itself is contained in @counter and access to it is + * serialized with @lock_mutex. */ -/* Note that we have to ensure interrupts are disabled in case we're - * interrupted by some other code that wants to grab the same read lock */ -static __inline__ void arch_read_lock(arch_rwlock_t *rw) +/* 1 - lock taken successfully */ +static inline int arch_read_trylock(arch_rwlock_t *rw) { + int ret = 0; unsigned long flags; - local_irq_save(flags); - arch_spin_lock_flags(&rw->lock, flags); - rw->counter++; - arch_spin_unlock(&rw->lock); - local_irq_restore(flags); -} -/* Note that we have to ensure interrupts are disabled in case we're - * interrupted by some other code that wants to grab the same read lock */ -static __inline__ void arch_read_unlock(arch_rwlock_t *rw) -{ - unsigned long flags; local_irq_save(flags); - arch_spin_lock_flags(&rw->lock, flags); - rw->counter--; - arch_spin_unlock(&rw->lock); + arch_spin_lock(&(rw->lock_mutex)); + + /* + * zero means writer holds the lock exclusively, deny Reader. + * Otherwise grant lock to first/subseq reader + */ + if (rw->counter > 0) { + rw->counter--; + ret = 1; + } + + arch_spin_unlock(&(rw->lock_mutex)); local_irq_restore(flags); + + return ret; } -/* Note that we have to ensure interrupts are disabled in case we're - * interrupted by some other code that wants to grab the same read lock */ -static __inline__ int arch_read_trylock(arch_rwlock_t *rw) +/* 1 - lock taken successfully */ +static inline int arch_write_trylock(arch_rwlock_t *rw) { + int ret = 0; unsigned long flags; - retry: + local_irq_save(flags); - if (arch_spin_trylock(&rw->lock)) { - rw->counter++; - arch_spin_unlock(&rw->lock); - local_irq_restore(flags); - return 1; + arch_spin_lock(&(rw->lock_mutex)); + + /* + * If reader(s) hold lock (lock < __ARCH_RW_LOCK_UNLOCKED__), + * deny writer. Otherwise if unlocked grant to writer + * Hence the claim that Linux rwlocks are unfair to writers. + * (can be starved for an indefinite time by readers). + */ + if (rw->counter == __ARCH_RW_LOCK_UNLOCKED__) { + rw->counter = 0; + ret = 1; } - + arch_spin_unlock(&(rw->lock_mutex)); local_irq_restore(flags); - /* If write-locked, we fail to acquire the lock */ - if (rw->counter < 0) - return 0; - /* Wait until we have a realistic chance at the lock */ - while (arch_spin_is_locked(&rw->lock) && rw->counter >= 0) + return ret; +} + +static inline void arch_read_lock(arch_rwlock_t *rw) +{ + while (!arch_read_trylock(rw)) cpu_relax(); +} - goto retry; +static inline void arch_write_lock(arch_rwlock_t *rw) +{ + while (!arch_write_trylock(rw)) + cpu_relax(); } -/* Note that we have to ensure interrupts are disabled in case we're - * interrupted by some other code that wants to read_trylock() this lock */ -static __inline__ void arch_write_lock(arch_rwlock_t *rw) +static inline void arch_read_unlock(arch_rwlock_t *rw) { unsigned long flags; -retry: - local_irq_save(flags); - arch_spin_lock_flags(&rw->lock, flags); - if (rw->counter != 0) { - arch_spin_unlock(&rw->lock); - local_irq_restore(flags); - - while (rw->counter != 0) - cpu_relax(); - - goto retry; - } - - rw->counter = -1; /* mark as write-locked */ - mb(); + local_irq_save(flags); + arch_spin_lock(&(rw->lock_mutex)); + rw->counter++; + arch_spin_unlock(&(rw->lock_mutex)); local_irq_restore(flags); } -static __inline__ void arch_write_unlock(arch_rwlock_t *rw) -{ - rw->counter = 0; - arch_spin_unlock(&rw->lock); -} - -/* Note that we have to ensure interrupts are disabled in case we're - * interrupted by some other code that wants to read_trylock() this lock */ -static __inline__ int arch_write_trylock(arch_rwlock_t *rw) +static inline void arch_write_unlock(arch_rwlock_t *rw) { unsigned long flags; - int result = 0; local_irq_save(flags); - if (arch_spin_trylock(&rw->lock)) { - if (rw->counter == 0) { - rw->counter = -1; - result = 1; - } else { - /* Read-locked. Oh well. */ - arch_spin_unlock(&rw->lock); - } - } + arch_spin_lock(&(rw->lock_mutex)); + rw->counter = __ARCH_RW_LOCK_UNLOCKED__; + arch_spin_unlock(&(rw->lock_mutex)); local_irq_restore(flags); - - return result; } #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/parisc/include/asm/spinlock_types.h b/arch/parisc/include/asm/spinlock_types.h index 42979c5704dc..ca39ee350c3f 100644 --- a/arch/parisc/include/asm/spinlock_types.h +++ b/arch/parisc/include/asm/spinlock_types.h @@ -12,11 +12,19 @@ typedef struct { #endif } arch_spinlock_t; + +/* counter: + * Unlocked : 0x0100_0000 + * Read lock(s) : 0x00FF_FFFF to 0x01 (Multiple Readers decrement it) + * Write lock : 0x0, but only if prior value is "unlocked" 0x0100_0000 + */ typedef struct { - arch_spinlock_t lock; - volatile int counter; + arch_spinlock_t lock_mutex; + volatile unsigned int counter; } arch_rwlock_t; -#define __ARCH_RW_LOCK_UNLOCKED { __ARCH_SPIN_LOCK_UNLOCKED, 0 } +#define __ARCH_RW_LOCK_UNLOCKED__ 0x01000000 +#define __ARCH_RW_LOCK_UNLOCKED { .lock_mutex = __ARCH_SPIN_LOCK_UNLOCKED, \ + .counter = __ARCH_RW_LOCK_UNLOCKED__ } #endif diff --git a/arch/parisc/kernel/alternative.c b/arch/parisc/kernel/alternative.c index 3c66d5c4d90d..fa28c4c9f972 100644 --- a/arch/parisc/kernel/alternative.c +++ b/arch/parisc/kernel/alternative.c @@ -25,6 +25,22 @@ void __init_or_module apply_alternatives(struct alt_instr *start, struct alt_instr *entry; int index = 0, applied = 0; int num_cpus = num_online_cpus(); + u32 cond_check; + + cond_check = ALT_COND_ALWAYS | + ((num_cpus == 1) ? ALT_COND_NO_SMP : 0) | + ((cache_info.dc_size == 0) ? ALT_COND_NO_DCACHE : 0) | + ((cache_info.ic_size == 0) ? ALT_COND_NO_ICACHE : 0) | + (running_on_qemu ? ALT_COND_RUN_ON_QEMU : 0) | + ((split_tlb == 0) ? ALT_COND_NO_SPLIT_TLB : 0) | + /* + * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit + * set (bit #61, big endian), we have to flush and sync every + * time IO-PDIR is changed in Ike/Astro. + */ + (((boot_cpu_data.cpu_type > pcxw_) && + ((boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC) == 0)) + ? ALT_COND_NO_IOC_FDC : 0); for (entry = start; entry < end; entry++, index++) { @@ -38,29 +54,14 @@ void __init_or_module apply_alternatives(struct alt_instr *start, WARN_ON(!cond); - if (cond != ALT_COND_ALWAYS && no_alternatives) + if ((cond & ALT_COND_ALWAYS) == 0 && no_alternatives) continue; pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n", index, cond, len, from, replacement); - if ((cond & ALT_COND_NO_SMP) && (num_cpus != 1)) - continue; - if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0)) - continue; - if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0)) - continue; - if ((cond & ALT_COND_RUN_ON_QEMU) && !running_on_qemu) - continue; - - /* - * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit - * set (bit #61, big endian), we have to flush and sync every - * time IO-PDIR is changed in Ike/Astro. - */ - if ((cond & ALT_COND_NO_IOC_FDC) && - ((boot_cpu_data.cpu_type <= pcxw_) || - (boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC))) + /* Bounce out if none of the conditions are true. */ + if ((cond & cond_check) == 0) continue; /* Want to replace pdtlb by a pdtlb,l instruction? */ diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index e5fcfb70cc7c..e76c86619949 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -560,33 +560,23 @@ void do_cpu_irq_mask(struct pt_regs *regs) goto out; } -static struct irqaction timer_action = { - .handler = timer_interrupt, - .name = "timer", - .flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL, -}; - -#ifdef CONFIG_SMP -static struct irqaction ipi_action = { - .handler = ipi_interrupt, - .name = "IPI", - .flags = IRQF_PERCPU, -}; -#endif - static void claim_cpu_irqs(void) { + unsigned long flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL; int i; + for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) { irq_set_chip_and_handler(i, &cpu_interrupt_type, handle_percpu_irq); } irq_set_handler(TIMER_IRQ, handle_percpu_irq); - setup_irq(TIMER_IRQ, &timer_action); + if (request_irq(TIMER_IRQ, timer_interrupt, flags, "timer", NULL)) + pr_err("Failed to register timer interrupt\n"); #ifdef CONFIG_SMP irq_set_handler(IPI_IRQ, handle_percpu_irq); - setup_irq(IPI_IRQ, &ipi_action); + if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL)) + pr_err("Failed to register IPI interrupt\n"); #endif } diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 97ac707c6bff..f05c9d5b6b9e 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -935,7 +935,7 @@ ENTRY(lws_table) END(lws_table) /* End of lws table */ -#define __SYSCALL(nr, entry, nargs) ASM_ULONG_INSN entry +#define __SYSCALL(nr, entry) ASM_ULONG_INSN entry .align 8 ENTRY(sys_call_table) .export sys_call_table,data diff --git a/arch/parisc/kernel/syscalls/syscalltbl.sh b/arch/parisc/kernel/syscalls/syscalltbl.sh index 45b5bae26240..f7393a7b18aa 100644 --- a/arch/parisc/kernel/syscalls/syscalltbl.sh +++ b/arch/parisc/kernel/syscalls/syscalltbl.sh @@ -13,10 +13,10 @@ emit() { t_entry="$3" while [ $t_nxt -lt $t_nr ]; do - printf "__SYSCALL(%s, sys_ni_syscall, )\n" "${t_nxt}" + printf "__SYSCALL(%s,sys_ni_syscall)\n" "${t_nxt}" t_nxt=$((t_nxt+1)) done - printf "__SYSCALL(%s, %s, )\n" "${t_nxt}" "${t_entry}" + printf "__SYSCALL(%s,%s)\n" "${t_nxt}" "${t_entry}" } grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | ( |