From e937dd5782688928d8c4050237b93b0a51faebee Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 16 Aug 2016 11:29:17 +0100 Subject: [PATCH] arm64: debug: convert OS lock CPU hotplug notifier to new infrastructure The arm64 debug monitor initialisation code uses a CPU hotplug notifier to clear the OS lock when CPUs come online. This patch converts the code to the new hotplug mechanism. Cc: Sebastian Andrzej Siewior Reviewed-by: Lorenzo Pieralisi Signed-off-by: Will Deacon --- arch/arm64/kernel/debug-monitors.c | 30 ++++++------------------------ include/linux/cpuhotplug.h | 1 + 2 files changed, 7 insertions(+), 24 deletions(-) diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 2751ff9c0934..30821928106f 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -132,36 +132,18 @@ NOKPROBE_SYMBOL(disable_debug_monitors); /* * OS lock clearing. */ -static void clear_os_lock(void *unused) +static int clear_os_lock(unsigned int cpu) { asm volatile("msr oslar_el1, %0" : : "r" (0)); + isb(); + return 0; } -static int os_lock_notify(struct notifier_block *self, - unsigned long action, void *data) -{ - if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE) - clear_os_lock(NULL); - return NOTIFY_OK; -} - -static struct notifier_block os_lock_nb = { - .notifier_call = os_lock_notify, -}; - static int debug_monitors_init(void) { - cpu_notifier_register_begin(); - - /* Clear the OS lock. */ - on_each_cpu(clear_os_lock, NULL, 1); - isb(); - - /* Register hotplug handler. */ - __register_cpu_notifier(&os_lock_nb); - - cpu_notifier_register_done(); - return 0; + return cpuhp_setup_state(CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING, + "CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING", + clear_os_lock, NULL); } postcore_initcall(debug_monitors_init); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 3758fe6d5968..8c999a202452 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_ARM64_DEBUG_MONITORS_STARTING, CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING, CPUHP_AP_PERF_ARM_STARTING, CPUHP_AP_ARM_L2X0_STARTING,