1 files changed, 16 insertions, 32 deletions

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);