diff options
Diffstat (limited to 'include/linux/context_tracking_state.h')
| -rw-r--r-- | include/linux/context_tracking_state.h | 96 |
1 files changed, 63 insertions, 33 deletions
diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h index bbff5f7f8803..0b81248aa03e 100644 --- a/include/linux/context_tracking_state.h +++ b/include/linux/context_tracking_state.h @@ -7,23 +7,17 @@ #include <linux/context_tracking_irq.h> /* Offset to allow distinguishing irq vs. task-based idle entry/exit. */ -#define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1) +#define CT_NESTING_IRQ_NONIDLE ((LONG_MAX / 2) + 1) enum ctx_state { - CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */ - CONTEXT_KERNEL = 0, - CONTEXT_IDLE = 1, - CONTEXT_USER = 2, - CONTEXT_GUEST = 3, - CONTEXT_MAX = 4, + CT_STATE_DISABLED = -1, /* returned by ct_state() if unknown */ + CT_STATE_KERNEL = 0, + CT_STATE_IDLE = 1, + CT_STATE_USER = 2, + CT_STATE_GUEST = 3, + CT_STATE_MAX = 4, }; -/* Even value for idle, else odd. */ -#define RCU_DYNTICKS_IDX CONTEXT_MAX - -#define CT_STATE_MASK (CONTEXT_MAX - 1) -#define CT_DYNTICKS_MASK (~CT_STATE_MASK) - struct context_tracking { #ifdef CONFIG_CONTEXT_TRACKING_USER /* @@ -39,14 +33,50 @@ struct context_tracking { atomic_t state; #endif #ifdef CONFIG_CONTEXT_TRACKING_IDLE - long dynticks_nesting; /* Track process nesting level. */ - long dynticks_nmi_nesting; /* Track irq/NMI nesting level. */ + long nesting; /* Track process nesting level. */ + long nmi_nesting; /* Track irq/NMI nesting level. */ #endif }; +/* + * We cram two different things within the same atomic variable: + * + * CT_RCU_WATCHING_START CT_STATE_START + * | | + * v v + * MSB [ RCU watching counter ][ context_state ] LSB + * ^ ^ + * | | + * CT_RCU_WATCHING_END CT_STATE_END + * + * Bits are used from the LSB upwards, so unused bits (if any) will always be in + * upper bits of the variable. + */ #ifdef CONFIG_CONTEXT_TRACKING +#define CT_SIZE (sizeof(((struct context_tracking *)0)->state) * BITS_PER_BYTE) + +#define CT_STATE_WIDTH bits_per(CT_STATE_MAX - 1) +#define CT_STATE_START 0 +#define CT_STATE_END (CT_STATE_START + CT_STATE_WIDTH - 1) + +#define CT_RCU_WATCHING_MAX_WIDTH (CT_SIZE - CT_STATE_WIDTH) +#define CT_RCU_WATCHING_WIDTH (IS_ENABLED(CONFIG_RCU_DYNTICKS_TORTURE) ? 2 : CT_RCU_WATCHING_MAX_WIDTH) +#define CT_RCU_WATCHING_START (CT_STATE_END + 1) +#define CT_RCU_WATCHING_END (CT_RCU_WATCHING_START + CT_RCU_WATCHING_WIDTH - 1) +#define CT_RCU_WATCHING BIT(CT_RCU_WATCHING_START) + +#define CT_STATE_MASK GENMASK(CT_STATE_END, CT_STATE_START) +#define CT_RCU_WATCHING_MASK GENMASK(CT_RCU_WATCHING_END, CT_RCU_WATCHING_START) + +#define CT_UNUSED_WIDTH (CT_RCU_WATCHING_MAX_WIDTH - CT_RCU_WATCHING_WIDTH) + +static_assert(CT_STATE_WIDTH + + CT_RCU_WATCHING_WIDTH + + CT_UNUSED_WIDTH == + CT_SIZE); + DECLARE_PER_CPU(struct context_tracking, context_tracking); -#endif +#endif /* CONFIG_CONTEXT_TRACKING */ #ifdef CONFIG_CONTEXT_TRACKING_USER static __always_inline int __ct_state(void) @@ -56,47 +86,47 @@ static __always_inline int __ct_state(void) #endif #ifdef CONFIG_CONTEXT_TRACKING_IDLE -static __always_inline int ct_dynticks(void) +static __always_inline int ct_rcu_watching(void) { - return atomic_read(this_cpu_ptr(&context_tracking.state)) & CT_DYNTICKS_MASK; + return atomic_read(this_cpu_ptr(&context_tracking.state)) & CT_RCU_WATCHING_MASK; } -static __always_inline int ct_dynticks_cpu(int cpu) +static __always_inline int ct_rcu_watching_cpu(int cpu) { struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu); - return atomic_read(&ct->state) & CT_DYNTICKS_MASK; + return atomic_read(&ct->state) & CT_RCU_WATCHING_MASK; } -static __always_inline int ct_dynticks_cpu_acquire(int cpu) +static __always_inline int ct_rcu_watching_cpu_acquire(int cpu) { struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu); - return atomic_read_acquire(&ct->state) & CT_DYNTICKS_MASK; + return atomic_read_acquire(&ct->state) & CT_RCU_WATCHING_MASK; } -static __always_inline long ct_dynticks_nesting(void) +static __always_inline long ct_nesting(void) { - return __this_cpu_read(context_tracking.dynticks_nesting); + return __this_cpu_read(context_tracking.nesting); } -static __always_inline long ct_dynticks_nesting_cpu(int cpu) +static __always_inline long ct_nesting_cpu(int cpu) { struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu); - return ct->dynticks_nesting; + return ct->nesting; } -static __always_inline long ct_dynticks_nmi_nesting(void) +static __always_inline long ct_nmi_nesting(void) { - return __this_cpu_read(context_tracking.dynticks_nmi_nesting); + return __this_cpu_read(context_tracking.nmi_nesting); } -static __always_inline long ct_dynticks_nmi_nesting_cpu(int cpu) +static __always_inline long ct_nmi_nesting_cpu(int cpu) { struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu); - return ct->dynticks_nmi_nesting; + return ct->nmi_nesting; } #endif /* #ifdef CONFIG_CONTEXT_TRACKING_IDLE */ @@ -113,7 +143,7 @@ static __always_inline bool context_tracking_enabled_cpu(int cpu) return context_tracking_enabled() && per_cpu(context_tracking.active, cpu); } -static inline bool context_tracking_enabled_this_cpu(void) +static __always_inline bool context_tracking_enabled_this_cpu(void) { return context_tracking_enabled() && __this_cpu_read(context_tracking.active); } @@ -123,14 +153,14 @@ static inline bool context_tracking_enabled_this_cpu(void) * * Returns the current cpu's context tracking state if context tracking * is enabled. If context tracking is disabled, returns - * CONTEXT_DISABLED. This should be used primarily for debugging. + * CT_STATE_DISABLED. This should be used primarily for debugging. */ static __always_inline int ct_state(void) { int ret; if (!context_tracking_enabled()) - return CONTEXT_DISABLED; + return CT_STATE_DISABLED; preempt_disable(); ret = __ct_state(); |