Commit-ID: fe2a5cd8aa038e2b02fda983afc2083e94c04b4f Gitweb: http://git.kernel.org/tip/fe2a5cd8aa038e2b02fda983afc2083e94c04b4f Author: Sebastian Andrzej Siewior <bige...@linutronix.de> AuthorDate: Wed, 24 May 2017 10:15:25 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 26 May 2017 10:10:40 +0200
ARM/hw_breakpoint: Use cpuhp_setup_state_cpuslocked() arch_hw_breakpoint_init() holds get_online_cpus() while registerring the hotplug callbacks. cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Convert *_online_cpus() to the new interfaces while at it. Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Ingo Molnar <mi...@kernel.org> Acked-by: Mark Rutland <mark.rutl...@arm.com> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Will Deacon <will.dea...@arm.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Russell King <li...@armlinux.org.uk> Cc: linux-arm-ker...@lists.infradead.org Link: http://lkml.kernel.org/r/20170524081548.170940...@linutronix.de --- arch/arm/kernel/hw_breakpoint.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index be3b3fb..63cb4c7 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1090,7 +1090,7 @@ static int __init arch_hw_breakpoint_init(void) * driven low on this core and there isn't an architected way to * determine that. */ - get_online_cpus(); + cpus_read_lock(); register_undef_hook(&debug_reg_hook); /* @@ -1098,15 +1098,16 @@ static int __init arch_hw_breakpoint_init(void) * assume that a halting debugger will leave the world in a nice state * for us. */ - ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/hw_breakpoint:online", - dbg_reset_online, NULL); + ret = cpuhp_setup_state_cpuslocked(CPUHP_AP_ONLINE_DYN, + "arm/hw_breakpoint:online", + dbg_reset_online, NULL); unregister_undef_hook(&debug_reg_hook); if (WARN_ON(ret < 0) || !cpumask_empty(&debug_err_mask)) { core_num_brps = 0; core_num_wrps = 0; if (ret > 0) cpuhp_remove_state_nocalls(ret); - put_online_cpus(); + cpus_read_unlock(); return 0; } @@ -1124,7 +1125,7 @@ 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(); + cpus_read_unlock(); /* Register PM notifiers. */ pm_init();
