diff options
| -rw-r--r-- | arch/ia64/kernel/salinfo.c | 38 |
1 files changed, 10 insertions, 28 deletions
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c index 1eeffb7fbb16..5313007d5423 100644 --- a/arch/ia64/kernel/salinfo.c +++ b/arch/ia64/kernel/salinfo.c @@ -141,7 +141,7 @@ enum salinfo_state { struct salinfo_data { cpumask_t cpu_event; /* which cpus have outstanding events */ - struct semaphore mutex; + wait_queue_head_t read_wait; u8 *log_buffer; u64 log_size; u8 *oemdata; /* decoded oem data */ @@ -182,21 +182,6 @@ struct salinfo_platform_oemdata_parms { int ret; }; -/* Kick the mutex that tells user space that there is work to do. Instead of - * trying to track the state of the mutex across multiple cpus, in user - * context, interrupt context, non-maskable interrupt context and hotplug cpu, - * it is far easier just to grab the mutex if it is free then release it. - * - * This routine must be called with data_saved_lock held, to make the down/up - * operation atomic. - */ -static void -salinfo_work_to_do(struct salinfo_data *data) -{ - (void)(down_trylock(&data->mutex) ?: 0); - up(&data->mutex); -} - static void salinfo_platform_oemdata_cpu(void *context) { @@ -258,7 +243,7 @@ salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe) } cpumask_set_cpu(smp_processor_id(), &data->cpu_event); if (irqsafe) { - salinfo_work_to_do(data); + wake_up_interruptible(&data->read_wait); spin_unlock_irqrestore(&data_saved_lock, flags); } } @@ -271,14 +256,10 @@ extern void ia64_mlogbuf_dump(void); static void salinfo_timeout_check(struct salinfo_data *data) { - unsigned long flags; if (!data->open) return; - if (!cpumask_empty(&data->cpu_event)) { - spin_lock_irqsave(&data_saved_lock, flags); - salinfo_work_to_do(data); - spin_unlock_irqrestore(&data_saved_lock, flags); - } + if (!cpumask_empty(&data->cpu_event)) + wake_up_interruptible(&data->read_wait); } static void @@ -308,10 +289,11 @@ salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t int i, n, cpu = -1; retry: - if (cpumask_empty(&data->cpu_event) && down_trylock(&data->mutex)) { + if (cpumask_empty(&data->cpu_event)) { if (file->f_flags & O_NONBLOCK) return -EAGAIN; - if (down_interruptible(&data->mutex)) + if (wait_event_interruptible(data->read_wait, + !cpumask_empty(&data->cpu_event))) return -EINTR; } @@ -510,7 +492,7 @@ salinfo_log_clear(struct salinfo_data *data, int cpu) if (data->state == STATE_LOG_RECORD) { spin_lock_irqsave(&data_saved_lock, flags); cpumask_set_cpu(cpu, &data->cpu_event); - salinfo_work_to_do(data); + wake_up_interruptible(&data->read_wait); spin_unlock_irqrestore(&data_saved_lock, flags); } return 0; @@ -582,7 +564,7 @@ salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu i < ARRAY_SIZE(salinfo_data); ++i, ++data) { cpumask_set_cpu(cpu, &data->cpu_event); - salinfo_work_to_do(data); + wake_up_interruptible(&data->read_wait); } spin_unlock_irqrestore(&data_saved_lock, flags); break; @@ -640,7 +622,7 @@ salinfo_init(void) for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) { data = salinfo_data + i; data->type = i; - sema_init(&data->mutex, 1); + init_waitqueue_head(&data->read_wait); dir = proc_mkdir(salinfo_log_name[i], salinfo_dir); if (!dir) continue; |