Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e5b61baf authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

arm: Convert VFP hotplug notifiers to state machine 



Straight forward conversion plus commentary why code which is executed
in hotplug callbacks needs to be invoked before installing them.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.713612993@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 148b9e2a

arch/arm/vfp/vfpmodule.c

+17 −11
Original line number Diff line number Diff line
@@ -643,19 +643,19 @@ int vfp_restore_user_hwstate(struct user_vfp __user *ufp, 
 * hardware state at every thread switch.  We clear our held state when

 * a CPU has been killed, indicating that the VFP hardware doesn't contain

 * a threads VFP state.  When a CPU starts up, we re-enable access to the

 * VFP hardware.

 *

 * Both CPU_DYING and CPU_STARTING are called on the CPU which

 * VFP hardware. The callbacks below are called on the CPU which

 * is being offlined/onlined.

 */

static int vfp_hotplug(struct notifier_block *b, unsigned long action,

	void *hcpu)

static int vfp_dying_cpu(unsigned int cpu)

{

	vfp_force_reload(cpu, current_thread_info());

	return 0;

}



static int vfp_starting_cpu(unsigned int unused)

{

	if (action == CPU_DYING || action == CPU_DYING_FROZEN)

		vfp_current_hw_state[(long)hcpu] = NULL;

	else if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)

	vfp_enable(NULL);

	return NOTIFY_OK;

	return 0;

}



void vfp_kmode_exception(void)
@@ -732,6 +732,10 @@ static int __init vfp_init(void) 
	unsigned int vfpsid;

	unsigned int cpu_arch = cpu_architecture();



	/*

	 * Enable the access to the VFP on all online CPUs so the

	 * following test on FPSID will succeed.

	 */

	if (cpu_arch >= CPU_ARCH_ARMv6)

		on_each_cpu(vfp_enable, NULL, 1);
@@ -794,7 +798,9 @@ static int __init vfp_init(void) 
		VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT;

	}



	hotcpu_notifier(vfp_hotplug, 0);

	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_VFP_STARTING,

				  "AP_ARM_VFP_STARTING", vfp_starting_cpu,

				  vfp_dying_cpu);



	vfp_vector = vfp_support_entry;

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ enum cpuhp_state { 
	CPUHP_AP_PERF_X86_CQM_STARTING,

	CPUHP_AP_PERF_X86_CSTATE_STARTING,

	CPUHP_AP_PERF_XTENSA_STARTING,

	CPUHP_AP_ARM_VFP_STARTING,

	CPUHP_AP_NOTIFY_STARTING,

	CPUHP_AP_ONLINE,

	CPUHP_TEARDOWN_CPU,