Commit 98903688 authored by Helge Deller's avatar Helge Deller
Browse files

parisc: Rewrite arch_cpu_idle_dead() for CPU hotplugging 



Let the PDC firmware put the CPU into firmware idle loop with the
pdc_cpu_rendezvous() function.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 88b3aac6

arch/parisc/kernel/process.c

+24 −3
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <linux/rcupdate.h>

#include <linux/random.h>

#include <linux/nmi.h>

#include <linux/sched/hotplug.h>



#include <asm/io.h>

#include <asm/asm-offsets.h>
@@ -46,6 +47,7 @@ 
#include <asm/pdc_chassis.h>

#include <asm/unwind.h>

#include <asm/sections.h>

#include <asm/cacheflush.h>



#define COMMAND_GLOBAL  F_EXTEND(0xfffe0030)

#define CMD_RESET       5       /* reset any module */
@@ -158,10 +160,29 @@ void release_thread(struct task_struct *dead_task) 
int running_on_qemu __ro_after_init;

EXPORT_SYMBOL(running_on_qemu);



void __cpuidle arch_cpu_idle_dead(void)

/*

 * Called from the idle thread for the CPU which has been shutdown.

 */

void arch_cpu_idle_dead(void)

{

	/* nop on real hardware, qemu will offline CPU. */

	asm volatile("or %%r31,%%r31,%%r31\n":::);

#ifdef CONFIG_HOTPLUG_CPU

	idle_task_exit();



	local_irq_disable();



	/* Tell __cpu_die() that this CPU is now safe to dispose of. */

	(void)cpu_report_death();



	/* Ensure that the cache lines are written out. */

	flush_cache_all_local();

	flush_tlb_all_local(NULL);



	/* Let PDC firmware put CPU into firmware idle loop. */

	__pdc_cpu_rendezvous();



	pr_warn("PDC does not provide rendezvous function.\n");

#endif

	while (1);

}



void __cpuidle arch_cpu_idle(void)