diff options
| -rw-r--r-- | arch/s390/kernel/smp.c | 181 |
1 files changed, 77 insertions, 104 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 83a4ea6e3d60..432deb2d9795 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -54,19 +54,18 @@ cpumask_t cpu_possible_map = CPU_MASK_NONE; static struct task_struct *current_set[NR_CPUS]; static void smp_ext_bitcall(int, ec_bit_sig); -static void smp_ext_bitcall_others(ec_bit_sig); /* - * Structure and data for smp_call_function(). This is designed to minimise - * static memory requirements. It also looks cleaner. + * Structure and data for __smp_call_function_map(). This is designed to + * minimise static memory requirements. It also looks cleaner. */ static DEFINE_SPINLOCK(call_lock); struct call_data_struct { void (*func) (void *info); void *info; - atomic_t started; - atomic_t finished; + cpumask_t started; + cpumask_t finished; int wait; }; @@ -81,118 +80,113 @@ static void do_call_function(void) void *info = call_data->info; int wait = call_data->wait; - atomic_inc(&call_data->started); + cpu_set(smp_processor_id(), call_data->started); (*func)(info); if (wait) - atomic_inc(&call_data->finished); + cpu_set(smp_processor_id(), call_data->finished);; } -/* - * this function sends a 'generic call function' IPI to all other CPUs - * in the system. - */ - -int smp_call_function (void (*func) (void *info), void *info, int nonatomic, - int wait) -/* - * [SUMMARY] Run a function on all other CPUs. - * <func> The function to run. This must be fast and non-blocking. - * <info> An arbitrary pointer to pass to the function. - * <nonatomic> currently unused. - * <wait> If true, wait (atomically) until function has completed on other CPUs. - * [RETURNS] 0 on success, else a negative status code. Does not return until - * remote CPUs are nearly ready to execute <<func>> or are or have executed. - * - * You must not call this function with disabled interrupts or from a - * hardware interrupt handler. - */ +static void __smp_call_function_map(void (*func) (void *info), void *info, + int nonatomic, int wait, cpumask_t map) { struct call_data_struct data; - int cpus = num_online_cpus()-1; + int cpu, local = 0; - if (cpus <= 0) - return 0; + /* + * Can deadlock when interrupts are disabled or if in wrong context, + * caller must disable preemption + */ + WARN_ON(irqs_disabled() || in_irq() || preemptible()); - /* Can deadlock when interrupts are disabled or if in wrong context */ - WARN_ON(irqs_disabled() || in_irq()); + /* + * Check for local function call. We have to have the same call order + * as in on_each_cpu() because of machine_restart_smp(). + */ + if (cpu_isset(smp_processor_id(), map)) { + local = 1; + cpu_clear(smp_processor_id(), map); + } + + cpus_and(map, map, cpu_online_map); + if (cpus_empty(map)) + goto out; data.func = func; data.info = info; - atomic_set(&data.started, 0); + data.started = CPU_MASK_NONE; data.wait = wait; if (wait) - atomic_set(&data.finished, 0); + data.finished = CPU_MASK_NONE; spin_lock_bh(&call_lock); call_data = &data; - /* Send a message to all other CPUs and wait for them to respond */ - smp_ext_bitcall_others(ec_call_function); + + for_each_cpu_mask(cpu, map) + smp_ext_bitcall(cpu, ec_call_function); /* Wait for response */ - while (atomic_read(&data.started) != cpus) + while (!cpus_equal(map, data.started)) cpu_relax(); if (wait) - while (atomic_read(&data.finished) != cpus) + while (!cpus_equal(map, data.finished)) cpu_relax(); + spin_unlock_bh(&call_lock); - return 0; +out: + local_irq_disable(); + if (local) + func(info); + local_irq_enable(); } /* - * Call a function on one CPU - * cpu : the CPU the function should be executed on + * smp_call_function: + * @func: the function to run; this must be fast and non-blocking + * @info: an arbitrary pointer to pass to the function + * @nonatomic: unused + * @wait: if true, wait (atomically) until function has completed on other CPUs * - * You must not call this function with disabled interrupts or from a - * hardware interrupt handler. You may call it from a bottom half. + * Run a function on all other CPUs. * - * It is guaranteed that the called function runs on the specified CPU, - * preemption is disabled. + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler. Must be called with preemption disabled. + * You may call it from a bottom half. */ -int smp_call_function_on(void (*func) (void *info), void *info, - int nonatomic, int wait, int cpu) +int smp_call_function(void (*func) (void *info), void *info, int nonatomic, + int wait) { - struct call_data_struct data; - int curr_cpu; - - if (!cpu_online(cpu)) - return -EINVAL; - - /* Can deadlock when interrupts are disabled or if in wrong context */ - WARN_ON(irqs_disabled() || in_irq()); - - /* disable preemption for local function call */ - curr_cpu = get_cpu(); - - if (curr_cpu == cpu) { - /* direct call to function */ - func(info); - put_cpu(); - return 0; - } - - data.func = func; - data.info = info; - atomic_set(&data.started, 0); - data.wait = wait; - if (wait) - atomic_set(&data.finished, 0); - - spin_lock_bh(&call_lock); - call_data = &data; - smp_ext_bitcall(cpu, ec_call_function); + cpumask_t map; - /* Wait for response */ - while (atomic_read(&data.started) != 1) - cpu_relax(); + map = cpu_online_map; + cpu_clear(smp_processor_id(), map); + __smp_call_function_map(func, info, nonatomic, wait, map); + return 0; +} +EXPORT_SYMBOL(smp_call_function); - if (wait) - while (atomic_read(&data.finished) != 1) - cpu_relax(); +/* + * smp_call_function_on: + * @func: the function to run; this must be fast and non-blocking + * @info: an arbitrary pointer to pass to the function + * @nonatomic: unused + * @wait: if true, wait (atomically) until function has completed on other CPUs + * @cpu: the CPU where func should run + * + * Run a function on one processor. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler. Must be called with preemption disabled. + * You may call it from a bottom half. + */ +int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic, + int wait, int cpu) +{ + cpumask_t map = CPU_MASK_NONE; - spin_unlock_bh(&call_lock); - put_cpu(); + cpu_set(cpu, map); + __smp_call_function_map(func, info, nonatomic, wait, map); return 0; } EXPORT_SYMBOL(smp_call_function_on); @@ -325,26 +319,6 @@ static void smp_ext_bitcall(int cpu, ec_bit_sig sig) udelay(10); } -/* - * Send an external call sigp to every other cpu in the system and - * return without waiting for its completion. - */ -static void smp_ext_bitcall_others(ec_bit_sig sig) -{ - int cpu; - - for_each_online_cpu(cpu) { - if (cpu == smp_processor_id()) - continue; - /* - * Set signaling bit in lowcore of target cpu and kick it - */ - set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast); - while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy) - udelay(10); - } -} - #ifndef CONFIG_64BIT /* * this function sends a 'purge tlb' signal to another CPU. @@ -807,6 +781,5 @@ EXPORT_SYMBOL(cpu_possible_map); EXPORT_SYMBOL(lowcore_ptr); EXPORT_SYMBOL(smp_ctl_set_bit); EXPORT_SYMBOL(smp_ctl_clear_bit); -EXPORT_SYMBOL(smp_call_function); EXPORT_SYMBOL(smp_get_cpu); EXPORT_SYMBOL(smp_put_cpu); |
