diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index 26a6bf77d272..948b73148d56 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -857,7 +857,7 @@ void hw_breakpoint_thread_switch(struct task_struct *next) /* * CPU initialisation. */ -static void hw_breakpoint_reset(void *unused) +static int hw_breakpoint_reset(unsigned int cpu) { int i; struct perf_event **slots; @@ -888,28 +888,14 @@ static void hw_breakpoint_reset(void *unused) write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL); } } -} -static int hw_breakpoint_reset_notify(struct notifier_block *self, - unsigned long action, - void *hcpu) -{ - if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE) { - local_irq_disable(); - hw_breakpoint_reset(NULL); - local_irq_enable(); - } - return NOTIFY_OK; + return 0; } -static struct notifier_block hw_breakpoint_reset_nb = { - .notifier_call = hw_breakpoint_reset_notify, -}; - #ifdef CONFIG_CPU_PM -extern void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)); +extern void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int)); #else -static inline void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) +static inline void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int)) { } #endif @@ -919,36 +905,34 @@ static inline void cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) */ static int __init arch_hw_breakpoint_init(void) { + int ret; + core_num_brps = get_num_brps(); core_num_wrps = get_num_wrps(); pr_info("found %d breakpoint and %d watchpoint registers.\n", core_num_brps, core_num_wrps); - cpu_notifier_register_begin(); - - /* - * Reset the breakpoint resources. We assume that a halting - * debugger will leave the world in a nice state for us. - */ - smp_call_function(hw_breakpoint_reset, NULL, 1); - hw_breakpoint_reset(NULL); - /* Register debug fault handlers. */ hook_debug_fault_code(DBG_ESR_EVT_HWBP, breakpoint_handler, SIGTRAP, TRAP_HWBKPT, "hw-breakpoint handler"); hook_debug_fault_code(DBG_ESR_EVT_HWWP, watchpoint_handler, SIGTRAP, TRAP_HWBKPT, "hw-watchpoint handler"); - /* Register hotplug notifier. */ - __register_cpu_notifier(&hw_breakpoint_reset_nb); - - cpu_notifier_register_done(); + /* + * Reset the breakpoint resources. We assume that a halting + * debugger will leave the world in a nice state for us. + */ + ret = cpuhp_setup_state(CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING, + "CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING", + hw_breakpoint_reset, NULL); + if (ret) + pr_err("failed to register CPU hotplug notifier: %d\n", ret); /* Register cpu_suspend hw breakpoint restore hook */ cpu_suspend_set_dbg_restorer(hw_breakpoint_reset); - return 0; + return ret; } arch_initcall(arch_hw_breakpoint_init); diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index b616e365cee3..ad734142070d 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -23,8 +23,8 @@ unsigned long *sleep_save_stash; * time the notifier runs debug exceptions might have been enabled already, * with HW breakpoints registers content still in an unknown state. */ -static void (*hw_breakpoint_restore)(void *); -void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) +static int (*hw_breakpoint_restore)(unsigned int); +void __init cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int)) { /* Prevent multiple restore hook initializations */ if (WARN_ON(hw_breakpoint_restore)) @@ -34,6 +34,8 @@ void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) void notrace __cpu_suspend_exit(void) { + unsigned int cpu = smp_processor_id(); + /* * We are resuming from reset with the idmap active in TTBR0_EL1. * We must uninstall the idmap and restore the expected MMU @@ -45,7 +47,7 @@ void notrace __cpu_suspend_exit(void) * Restore per-cpu offset before any kernel * subsystem relying on it has a chance to run. */ - set_my_cpu_offset(per_cpu_offset(smp_processor_id())); + set_my_cpu_offset(per_cpu_offset(cpu)); /* * Restore HW breakpoint registers to sane values @@ -53,7 +55,7 @@ void notrace __cpu_suspend_exit(void) * through local_dbg_restore. */ if (hw_breakpoint_restore) - hw_breakpoint_restore(NULL); + hw_breakpoint_restore(cpu); } /* diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 242bf530edfc..3758fe6d5968 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -45,6 +45,7 @@ enum cpuhp_state { CPUHP_AP_PERF_METAG_STARTING, CPUHP_AP_MIPS_OP_LOONGSON3_STARTING, CPUHP_AP_ARM_VFP_STARTING, + CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING, CPUHP_AP_PERF_ARM_STARTING, CPUHP_AP_ARM_L2X0_STARTING, CPUHP_AP_ARM_ARCH_TIMER_STARTING,