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author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-11-17 19:35:36 +0100 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2016-11-22 23:34:41 +0100 |
commit | 9b377e217f0bd07f972d89ed0963df92818beffd (patch) | |
tree | 49b001930d18b9f9651ac9b3199fb7e0deca58df | |
parent | arm/bL_switcher: Convert to hotplug state machine (diff) | |
download | linux-9b377e217f0bd07f972d89ed0963df92818beffd.tar.xz linux-9b377e217f0bd07f972d89ed0963df92818beffd.zip |
ARM/hw_breakpoint: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
smp_call_function_single() has been removed because the function is already
invoked on the target CPU.
[ tglx: Added protection agaist hotplug back according to discussion with Will ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: rt@linuxtronix.de
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20161117183541.8588-16-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index b8df45883cf7..188180b5523d 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -925,9 +925,9 @@ static bool core_has_os_save_restore(void) } } -static void reset_ctrl_regs(void *unused) +static void reset_ctrl_regs(unsigned int cpu) { - int i, raw_num_brps, err = 0, cpu = smp_processor_id(); + int i, raw_num_brps, err = 0; u32 val; /* @@ -1020,25 +1020,20 @@ out_mdbgen: cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu)); } -static int dbg_reset_notify(struct notifier_block *self, - unsigned long action, void *cpu) +static int dbg_reset_online(unsigned int cpu) { - if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE) - smp_call_function_single((int)cpu, reset_ctrl_regs, NULL, 1); - - return NOTIFY_OK; + local_irq_disable(); + reset_ctrl_regs(cpu); + local_irq_enable(); + return 0; } -static struct notifier_block dbg_reset_nb = { - .notifier_call = dbg_reset_notify, -}; - #ifdef CONFIG_CPU_PM static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action, void *v) { if (action == CPU_PM_EXIT) - reset_ctrl_regs(NULL); + reset_ctrl_regs(smp_processor_id()); return NOTIFY_OK; } @@ -1059,6 +1054,8 @@ static inline void pm_init(void) static int __init arch_hw_breakpoint_init(void) { + int ret; + debug_arch = get_debug_arch(); if (!debug_arch_supported()) { @@ -1072,25 +1069,28 @@ static int __init arch_hw_breakpoint_init(void) core_num_brps = get_num_brps(); core_num_wrps = get_num_wrps(); - cpu_notifier_register_begin(); - /* * We need to tread carefully here because DBGSWENABLE may be * driven low on this core and there isn't an architected way to * determine that. */ + get_online_cpus(); register_undef_hook(&debug_reg_hook); /* - * Reset the breakpoint resources. We assume that a halting - * debugger will leave the world in a nice state for us. + * Register CPU notifier which resets the breakpoint resources. We + * assume that a halting debugger will leave the world in a nice state + * for us. */ - on_each_cpu(reset_ctrl_regs, NULL, 1); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/hw_breakpoint:online", + dbg_reset_online, NULL); unregister_undef_hook(&debug_reg_hook); - if (!cpumask_empty(&debug_err_mask)) { + if (WARN_ON(ret < 0) || !cpumask_empty(&debug_err_mask)) { core_num_brps = 0; core_num_wrps = 0; - cpu_notifier_register_done(); + if (ret > 0) + cpuhp_remove_state_nocalls(ret); + put_online_cpus(); return 0; } @@ -1108,12 +1108,9 @@ static int __init arch_hw_breakpoint_init(void) TRAP_HWBKPT, "watchpoint debug exception"); hook_ifault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP, TRAP_HWBKPT, "breakpoint debug exception"); + put_online_cpus(); - /* Register hotplug and PM notifiers. */ - __register_cpu_notifier(&dbg_reset_nb); - - cpu_notifier_register_done(); - + /* Register PM notifiers. */ pm_init(); return 0; } |