From: Thomas Gleixner Date: Fri, 13 Nov 2020 15:02:17 +0100 Subject: [PATCH 10/12] preempt: Cleanup the macro maze a bit Make the macro maze consistent and prepare it for adding the RT variant for BH accounting. - Use nmi_count() for the NMI portion of preempt count - Introduce in_hardirq() to make the naming consistent and non-ambiguos - Use the macros to create combined checks (e.g. in_task()) so the softirq representation for RT just falls into place. - Update comments and move the deprecated macros aside Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20201113141733.864469886@linutronix.de Signed-off-by: Sebastian Andrzej Siewior --- include/linux/preempt.h | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -77,31 +77,33 @@ /* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */ #include +#define nmi_count() (preempt_count() & NMI_MASK) #define hardirq_count() (preempt_count() & HARDIRQ_MASK) #define softirq_count() (preempt_count() & SOFTIRQ_MASK) -#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \ - | NMI_MASK)) +#define irq_count() (nmi_count() | hardirq_count() | softirq_count()) /* - * Are we doing bottom half or hardware interrupt processing? + * Macros to retrieve the current execution context: * - * in_irq() - We're in (hard) IRQ context + * in_nmi() - We're in NMI context + * in_hardirq() - We're in hard IRQ context + * in_serving_softirq() - We're in softirq context + * in_task() - We're in task context + */ +#define in_nmi() (nmi_count()) +#define in_hardirq() (hardirq_count()) +#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) +#define in_task() (!(in_nmi() | in_hardirq() | in_serving_softirq())) + +/* + * The following macros are deprecated and should not be used in new code: + * in_irq() - Obsolete version of in_hardirq() * in_softirq() - We have BH disabled, or are processing softirqs * in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled - * in_serving_softirq() - We're in softirq context - * in_nmi() - We're in NMI context - * in_task() - We're in task context - * - * Note: due to the BH disabled confusion: in_softirq(),in_interrupt() really - * should not be used in new code. */ #define in_irq() (hardirq_count()) #define in_softirq() (softirq_count()) #define in_interrupt() (irq_count()) -#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET) -#define in_nmi() (preempt_count() & NMI_MASK) -#define in_task() (!(preempt_count() & \ - (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET))) /* * The preempt_count offset after preempt_disable();