From 5356297d12d9ee6f70d09485878904bc41bac422 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 12 May 2023 23:07:30 +0200 Subject: cpu/hotplug: Remove cpu_report_state() and related unused cruft No more users. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Oleksandr Natalenko Tested-by: Helge Deller # parisc Tested-by: Guilherme G. Piccoli # Steam Deck Link: https://lore.kernel.org/r/20230512205256.582584351@linutronix.de --- include/linux/cpu.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/cpu.h') diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 8582a7142623..68f69e8e4f19 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -184,8 +184,6 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void __noreturn arch_cpu_idle_dead(void); -int cpu_report_state(int cpu); -int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); void play_idle_precise(u64 duration_ns, u64 latency_ns); -- cgit v1.2.3 From bc088f9a0d5bdf12bb18980739336dfcc092e55b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 12 May 2023 23:07:41 +0200 Subject: cpu/hotplug: Remove unused state functions All users converted to the hotplug core mechanism. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Oleksandr Natalenko Tested-by: Helge Deller # parisc Tested-by: Guilherme G. Piccoli # Steam Deck Link: https://lore.kernel.org/r/20230512205256.972894276@linutronix.de --- include/linux/cpu.h | 2 -- kernel/smpboot.c | 75 ----------------------------------------------------- 2 files changed, 77 deletions(-) (limited to 'include/linux/cpu.h') diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 68f69e8e4f19..d321dbd53405 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -193,8 +193,6 @@ static inline void play_idle(unsigned long duration_us) } #ifdef CONFIG_HOTPLUG_CPU -bool cpu_wait_death(unsigned int cpu, int seconds); -bool cpu_report_death(void); void cpuhp_report_idle_dead(void); #else static inline void cpuhp_report_idle_dead(void) { } diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 1940f33a40a3..f47d8f375946 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -325,78 +325,3 @@ void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread) cpus_read_unlock(); } EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); - -#ifndef CONFIG_HOTPLUG_CORE_SYNC -static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) = ATOMIC_INIT(CPU_POST_DEAD); - -#ifdef CONFIG_HOTPLUG_CPU -/* - * Wait for the specified CPU to exit the idle loop and die. - */ -bool cpu_wait_death(unsigned int cpu, int seconds) -{ - int jf_left = seconds * HZ; - int oldstate; - bool ret = true; - int sleep_jf = 1; - - might_sleep(); - - /* The outgoing CPU will normally get done quite quickly. */ - if (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) == CPU_DEAD) - goto update_state_early; - udelay(5); - - /* But if the outgoing CPU dawdles, wait increasingly long times. */ - while (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) != CPU_DEAD) { - schedule_timeout_uninterruptible(sleep_jf); - jf_left -= sleep_jf; - if (jf_left <= 0) - break; - sleep_jf = DIV_ROUND_UP(sleep_jf * 11, 10); - } -update_state_early: - oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); -update_state: - if (oldstate == CPU_DEAD) { - /* Outgoing CPU died normally, update state. */ - smp_mb(); /* atomic_read() before update. */ - atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_POST_DEAD); - } else { - /* Outgoing CPU still hasn't died, set state accordingly. */ - if (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - &oldstate, CPU_BROKEN)) - goto update_state; - ret = false; - } - return ret; -} - -/* - * Called by the outgoing CPU to report its successful death. Return - * false if this report follows the surviving CPU's timing out. - * - * A separate "CPU_DEAD_FROZEN" is used when the surviving CPU - * timed out. This approach allows architectures to omit calls to - * cpu_check_up_prepare() and cpu_set_state_online() without defeating - * the next cpu_wait_death()'s polling loop. - */ -bool cpu_report_death(void) -{ - int oldstate; - int newstate; - int cpu = smp_processor_id(); - - oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); - do { - if (oldstate != CPU_BROKEN) - newstate = CPU_DEAD; - else - newstate = CPU_DEAD_FROZEN; - } while (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - &oldstate, newstate)); - return newstate == CPU_DEAD; -} - -#endif /* #ifdef CONFIG_HOTPLUG_CPU */ -#endif /* !CONFIG_HOTPLUG_CORE_SYNC */ -- cgit v1.2.3 From 7725acaa4f0c04fbefb0e0d342635b967bb7d414 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 14 Jun 2023 01:39:22 +0200 Subject: init: Provide arch_cpu_finalize_init() check_bugs() has become a dumping ground for all sorts of activities to finalize the CPU initialization before running the rest of the init code. Most are empty, a few do actual bug checks, some do alternative patching and some cobble a CPU advertisement string together.... Aside of that the current implementation requires duplicated function declaration and mostly empty header files for them. Provide a new function arch_cpu_finalize_init(). Provide a generic declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub inline otherwise. This requires a temporary #ifdef in start_kernel() which will be removed along with check_bugs() once the architectures are converted over. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de --- arch/Kconfig | 3 +++ include/linux/cpu.h | 6 ++++++ init/main.c | 4 ++++ 3 files changed, 13 insertions(+) (limited to 'include/linux/cpu.h') diff --git a/arch/Kconfig b/arch/Kconfig index 205fd23e0cad..171e6b5e61b8 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -285,6 +285,9 @@ config ARCH_HAS_DMA_SET_UNCACHED config ARCH_HAS_DMA_CLEAR_UNCACHED bool +config ARCH_HAS_CPU_FINALIZE_INIT + bool + # Select if arch init_task must go in the __init_task_data section config ARCH_TASK_STRUCT_ON_STACK bool diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 8582a7142623..4893c4ac026d 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -184,6 +184,12 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void __noreturn arch_cpu_idle_dead(void); +#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT +void arch_cpu_finalize_init(void); +#else +static inline void arch_cpu_finalize_init(void) { } +#endif + int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); diff --git a/init/main.c b/init/main.c index af50044deed5..77d53167f4c7 100644 --- a/init/main.c +++ b/init/main.c @@ -1078,7 +1078,11 @@ asmlinkage __visible void __init __no_sanitize_address __noreturn start_kernel(v taskstats_init_early(); delayacct_init(); + arch_cpu_finalize_init(); + /* Temporary conditional until everything has been converted */ +#ifndef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT check_bugs(); +#endif acpi_subsystem_init(); arch_post_acpi_subsys_init(); -- cgit v1.2.3