diff options
Diffstat (limited to 'include/linux/smp.h')
| -rw-r--r-- | include/linux/smp.h | 176 |
1 files changed, 128 insertions, 48 deletions
diff --git a/include/linux/smp.h b/include/linux/smp.h index a56f08ff3097..91d0ecf3b8d3 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -12,57 +12,108 @@ #include <linux/list.h> #include <linux/cpumask.h> #include <linux/init.h> -#include <linux/llist.h> +#include <linux/smp_types.h> typedef void (*smp_call_func_t)(void *info); +typedef bool (*smp_cond_func_t)(int cpu, void *info); + +/* + * structure shares (partial) layout with struct irq_work + */ struct __call_single_data { - struct llist_node llist; + struct __call_single_node node; smp_call_func_t func; void *info; - unsigned int flags; }; +#define CSD_INIT(_func, _info) \ + (struct __call_single_data){ .func = (_func), .info = (_info), } + /* Use __aligned() to avoid to use 2 cache lines for 1 csd */ typedef struct __call_single_data call_single_data_t __aligned(sizeof(struct __call_single_data)); +#define INIT_CSD(_csd, _func, _info) \ +do { \ + *(_csd) = CSD_INIT((_func), (_info)); \ +} while (0) + +/* + * Enqueue a llist_node on the call_single_queue; be very careful, read + * flush_smp_call_function_queue() in detail. + */ +extern void __smp_call_single_queue(int cpu, struct llist_node *node); + /* total number of cpus in this system (may exceed NR_CPUS) */ extern unsigned int total_cpus; int smp_call_function_single(int cpuid, smp_call_func_t func, void *info, int wait); +void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, + void *info, bool wait, const struct cpumask *mask); + +int smp_call_function_single_async(int cpu, call_single_data_t *csd); + /* - * Call a function on all processors + * Cpus stopping functions in panic. All have default weak definitions. + * Architecture-dependent code may override them. */ -int on_each_cpu(smp_call_func_t func, void *info, int wait); +void __noreturn panic_smp_self_stop(void); +void __noreturn nmi_panic_self_stop(struct pt_regs *regs); +void crash_smp_send_stop(void); /* - * Call a function on processors specified by mask, which might include - * the local one. + * Call a function on all processors */ -void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, - void *info, bool wait); +static inline void on_each_cpu(smp_call_func_t func, void *info, int wait) +{ + on_each_cpu_cond_mask(NULL, func, info, wait, cpu_online_mask); +} + +/** + * on_each_cpu_mask(): Run a function on processors specified by + * cpumask, which may include the local processor. + * @mask: The set of cpus to run on (only runs on online subset). + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @wait: If true, wait (atomically) until function has completed + * on other CPUs. + * + * If @wait is true, then returns once @func has returned. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. The + * exception is that it may be used during early boot while + * early_boot_irqs_disabled is set. + */ +static inline void on_each_cpu_mask(const struct cpumask *mask, + smp_call_func_t func, void *info, bool wait) +{ + on_each_cpu_cond_mask(NULL, func, info, wait, mask); +} /* * Call a function on each processor for which the supplied function * cond_func returns a positive value. This may include the local - * processor. + * processor. May be used during early boot while early_boot_irqs_disabled is + * set. Use local_irq_save/restore() instead of local_irq_disable/enable(). */ -void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), - smp_call_func_t func, void *info, bool wait, - gfp_t gfp_flags); - -void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info), - smp_call_func_t func, void *info, bool wait, - gfp_t gfp_flags, const struct cpumask *mask); +static inline void on_each_cpu_cond(smp_cond_func_t cond_func, + smp_call_func_t func, void *info, bool wait) +{ + on_each_cpu_cond_mask(cond_func, func, info, wait, cpu_online_mask); +} -int smp_call_function_single_async(int cpu, call_single_data_t *csd); +/* + * Architecture specific boot CPU setup. Defined as empty weak function in + * init/main.c. Architectures can override it. + */ +void __init smp_prepare_boot_cpu(void); #ifdef CONFIG_SMP #include <linux/preempt.h> -#include <linux/kernel.h> #include <linux/compiler.h> #include <linux/thread_info.h> #include <asm/smp.h> @@ -80,8 +131,15 @@ extern void smp_send_stop(void); /* * sends a 'reschedule' event to another CPU: */ -extern void smp_send_reschedule(int cpu); - +extern void arch_smp_send_reschedule(int cpu); +/* + * scheduler_ipi() is inline so can't be passed as callback reason, but the + * callsite IP should be sufficient for root-causing IPIs sent from here. + */ +#define smp_send_reschedule(cpu) ({ \ + trace_ipi_send_cpu(cpu, _RET_IP_, NULL); \ + arch_smp_send_reschedule(cpu); \ +}) /* * Prepare machine for booting other CPUs. @@ -101,7 +159,7 @@ extern void smp_cpus_done(unsigned int max_cpus); /* * Call a function on all other processors */ -int smp_call_function(smp_call_func_t func, void *info, int wait); +void smp_call_function(smp_call_func_t func, void *info, int wait); void smp_call_function_many(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait); @@ -110,6 +168,7 @@ int smp_call_function_any(const struct cpumask *mask, void kick_all_cpus_sync(void); void wake_up_all_idle_cpus(void); +bool cpus_peek_for_pending_ipi(const struct cpumask *mask); /* * Generic and arch helpers @@ -119,12 +178,6 @@ void generic_smp_call_function_single_interrupt(void); #define generic_smp_call_function_interrupt \ generic_smp_call_function_single_interrupt -/* - * Mark the boot cpu "online" so that it can call console drivers in - * printk() and can access its per-cpu storage. - */ -void smp_prepare_boot_cpu(void); - extern unsigned int setup_max_cpus; extern void __init setup_nr_cpu_ids(void); extern void __init smp_init(void); @@ -144,15 +197,13 @@ static inline void smp_send_stop(void) { } * These macros fold the SMP functionality into a single CPU system */ #define raw_smp_processor_id() 0 -static inline int up_smp_call_function(smp_call_func_t func, void *info) +static inline void up_smp_call_function(smp_call_func_t func, void *info) { - return 0; } #define smp_call_function(func, info, wait) \ (up_smp_call_function(func, info)) static inline void smp_send_reschedule(int cpu) { } -#define smp_prepare_boot_cpu() do {} while (0) #define smp_call_function_many(mask, func, info, wait) \ (up_smp_call_function(func, info)) static inline void call_function_init(void) { } @@ -166,10 +217,16 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, static inline void kick_all_cpus_sync(void) { } static inline void wake_up_all_idle_cpus(void) { } +static inline bool cpus_peek_for_pending_ipi(const struct cpumask *mask) +{ + return false; +} + +#define setup_max_cpus 0 #ifdef CONFIG_UP_LATE_INIT extern void __init up_late_init(void); -static inline void smp_init(void) { up_late_init(); } +static __always_inline void smp_init(void) { up_late_init(); } #else static inline void smp_init(void) { } #endif @@ -181,29 +238,46 @@ static inline int get_boot_cpu_id(void) #endif /* !SMP */ -/* - * smp_processor_id(): get the current CPU ID. +/** + * raw_smp_processor_id() - get the current (unstable) CPU id * - * if DEBUG_PREEMPT is enabled then we check whether it is - * used in a preemption-safe way. (smp_processor_id() is safe - * if it's used in a preemption-off critical section, or in - * a thread that is bound to the current CPU.) + * For then you know what you are doing and need an unstable + * CPU id. + */ + +/** + * smp_processor_id() - get the current (stable) CPU id + * + * This is the normal accessor to the CPU id and should be used + * whenever possible. + * + * The CPU id is stable when: * - * NOTE: raw_smp_processor_id() is for internal use only - * (smp_processor_id() is the preferred variant), but in rare - * instances it might also be used to turn off false positives - * (i.e. smp_processor_id() use that the debugging code reports but - * which use for some reason is legal). Don't use this to hack around - * the warning message, as your code might not work under PREEMPT. + * - IRQs are disabled; + * - preemption is disabled; + * - the task is CPU affine. + * + * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN + * when smp_processor_id() is used when the CPU id is not stable. + */ + +/* + * Allow the architecture to differentiate between a stable and unstable read. + * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a + * regular asm read for the stable. */ +#ifndef __smp_processor_id +#define __smp_processor_id() raw_smp_processor_id() +#endif + #ifdef CONFIG_DEBUG_PREEMPT extern unsigned int debug_smp_processor_id(void); # define smp_processor_id() debug_smp_processor_id() #else -# define smp_processor_id() raw_smp_processor_id() +# define smp_processor_id() __smp_processor_id() #endif -#define get_cpu() ({ preempt_disable(); smp_processor_id(); }) +#define get_cpu() ({ preempt_disable(); __smp_processor_id(); }) #define put_cpu() preempt_enable() /* @@ -212,8 +286,8 @@ static inline int get_boot_cpu_id(void) */ extern void arch_disable_smp_support(void); -extern void arch_enable_nonboot_cpus_begin(void); -extern void arch_enable_nonboot_cpus_end(void); +extern void arch_thaw_secondary_cpus_begin(void); +extern void arch_thaw_secondary_cpus_end(void); void smp_setup_processor_id(void); @@ -225,4 +299,10 @@ int smpcfd_prepare_cpu(unsigned int cpu); int smpcfd_dead_cpu(unsigned int cpu); int smpcfd_dying_cpu(unsigned int cpu); +#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG +bool csd_lock_is_stuck(void); +#else +static inline bool csd_lock_is_stuck(void) { return false; } +#endif + #endif /* __LINUX_SMP_H */ |