diff options
Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 76 |
1 files changed, 66 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index ee4c7609b649..bf90361bb70f 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -38,9 +38,11 @@ #include <asm/syscalls.h> #include <asm/smp.h> #include <asm/atomic.h> +#include <asm/time.h> +#include <asm/mmu.h> struct rtas_t rtas = { - .lock = SPIN_LOCK_UNLOCKED + .lock = __RAW_SPIN_LOCK_UNLOCKED }; EXPORT_SYMBOL(rtas); @@ -67,6 +69,28 @@ unsigned long rtas_rmo_buf; void (*rtas_flash_term_hook)(int); EXPORT_SYMBOL(rtas_flash_term_hook); +/* RTAS use home made raw locking instead of spin_lock_irqsave + * because those can be called from within really nasty contexts + * such as having the timebase stopped which would lockup with + * normal locks and spinlock debugging enabled + */ +static unsigned long lock_rtas(void) +{ + unsigned long flags; + + local_irq_save(flags); + preempt_disable(); + __raw_spin_lock_flags(&rtas.lock, flags); + return flags; +} + +static void unlock_rtas(unsigned long flags) +{ + __raw_spin_unlock(&rtas.lock); + local_irq_restore(flags); + preempt_enable(); +} + /* * call_rtas_display_status and call_rtas_display_status_delay * are designed only for very early low-level debugging, which @@ -79,7 +103,7 @@ static void call_rtas_display_status(char c) if (!rtas.base) return; - spin_lock_irqsave(&rtas.lock, s); + s = lock_rtas(); args->token = 10; args->nargs = 1; @@ -89,7 +113,7 @@ static void call_rtas_display_status(char c) enter_rtas(__pa(args)); - spin_unlock_irqrestore(&rtas.lock, s); + unlock_rtas(s); } static void call_rtas_display_status_delay(char c) @@ -411,8 +435,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) return -1; - /* Gotta do something different here, use global lock for now... */ - spin_lock_irqsave(&rtas.lock, s); + s = lock_rtas(); rtas_args = &rtas.args; rtas_args->token = token; @@ -439,8 +462,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...) outputs[i] = rtas_args->rets[i+1]; ret = (nret > 0)? rtas_args->rets[0]: 0; - /* Gotta do something different here, use global lock for now... */ - spin_unlock_irqrestore(&rtas.lock, s); + unlock_rtas(s); if (buff_copy) { log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0); @@ -692,6 +714,7 @@ static void rtas_percpu_suspend_me(void *info) { long rc = H_SUCCESS; unsigned long msr_save; + u16 slb_size = mmu_slb_size; int cpu; struct rtas_suspend_me_data *data = (struct rtas_suspend_me_data *)info; @@ -714,13 +737,16 @@ static void rtas_percpu_suspend_me(void *info) /* All other cpus are in H_JOIN, this cpu does * the suspend. */ + slb_set_size(SLB_MIN_SIZE); printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id()); data->error = rtas_call(data->token, 0, 1, NULL); - if (data->error) + if (data->error) { printk(KERN_DEBUG "ibm,suspend-me returned %d\n", data->error); + slb_set_size(slb_size); + } } else { printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n", smp_processor_id(), rc); @@ -837,7 +863,7 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) buff_copy = get_errorlog_buffer(); - spin_lock_irqsave(&rtas.lock, flags); + flags = lock_rtas(); rtas.args = args; enter_rtas(__pa(&rtas.args)); @@ -848,7 +874,7 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs) if (args.rets[0] == -1) errbuf = __fetch_rtas_last_error(buff_copy); - spin_unlock_irqrestore(&rtas.lock, flags); + unlock_rtas(flags); if (buff_copy) { if (errbuf) @@ -951,3 +977,33 @@ int __init early_init_dt_scan_rtas(unsigned long node, /* break now */ return 1; } + +static raw_spinlock_t timebase_lock; +static u64 timebase = 0; + +void __cpuinit rtas_give_timebase(void) +{ + unsigned long flags; + + local_irq_save(flags); + hard_irq_disable(); + __raw_spin_lock(&timebase_lock); + rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); + timebase = get_tb(); + __raw_spin_unlock(&timebase_lock); + + while (timebase) + barrier(); + rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); + local_irq_restore(flags); +} + +void __cpuinit rtas_take_timebase(void) +{ + while (!timebase) + barrier(); + __raw_spin_lock(&timebase_lock); + set_tb(timebase >> 32, timebase & 0xffffffff); + timebase = 0; + __raw_spin_unlock(&timebase_lock); +} |