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Unverified Commit 1447864b authored by Dengcheng Zhu's avatar Dengcheng Zhu Committed by Paul Burton
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MIPS: kexec: CPS systems to halt nonboot CPUs 



Share code between play_dead() and cps_kexec_nonboot_cpu(). Register the
latter to mp_ops for kexec.

Signed-off-by: default avatarDengcheng Zhu <dzhu@wavecomp.com>
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20567/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: rachel.mozes@intel.com
parent 62cac480

arch/mips/kernel/smp-cps.c

+55 −25
Original line number Diff line number Diff line
@@ -398,6 +398,55 @@ static void cps_smp_finish(void) 
	local_irq_enable();

}



#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_KEXEC)



enum cpu_death {

	CPU_DEATH_HALT,

	CPU_DEATH_POWER,

};



static void cps_shutdown_this_cpu(enum cpu_death death)

{

	unsigned int cpu, core, vpe_id;



	cpu = smp_processor_id();

	core = cpu_core(&cpu_data[cpu]);



	if (death == CPU_DEATH_HALT) {

		vpe_id = cpu_vpe_id(&cpu_data[cpu]);



		pr_debug("Halting core %d VP%d\n", core, vpe_id);

		if (cpu_has_mipsmt) {

			/* Halt this TC */

			write_c0_tchalt(TCHALT_H);

			instruction_hazard();

		} else if (cpu_has_vp) {

			write_cpc_cl_vp_stop(1 << vpe_id);



			/* Ensure that the VP_STOP register is written */

			wmb();

		}

	} else {

		pr_debug("Gating power to core %d\n", core);

		/* Power down the core */

		cps_pm_enter_state(CPS_PM_POWER_GATED);

	}

}



#ifdef CONFIG_KEXEC



static void cps_kexec_nonboot_cpu(void)

{

	if (cpu_has_mipsmt || cpu_has_vp)

		cps_shutdown_this_cpu(CPU_DEATH_HALT);

	else

		cps_shutdown_this_cpu(CPU_DEATH_POWER);

}



#endif /* CONFIG_KEXEC */



#endif /* CONFIG_HOTPLUG_CPU || CONFIG_KEXEC */



#ifdef CONFIG_HOTPLUG_CPU



static int cps_cpu_disable(void)
@@ -421,19 +470,15 @@ static int cps_cpu_disable(void) 
}



static unsigned cpu_death_sibling;

static enum {

	CPU_DEATH_HALT,

	CPU_DEATH_POWER,

} cpu_death;

static enum cpu_death cpu_death;



void play_dead(void)

{

	unsigned int cpu, core, vpe_id;

	unsigned int cpu;



	local_irq_disable();

	idle_task_exit();

	cpu = smp_processor_id();

	core = cpu_core(&cpu_data[cpu]);

	cpu_death = CPU_DEATH_POWER;



	pr_debug("CPU%d going offline\n", cpu);
@@ -456,25 +501,7 @@ void play_dead(void) 
	/* This CPU has chosen its way out */

	(void)cpu_report_death();



	if (cpu_death == CPU_DEATH_HALT) {

		vpe_id = cpu_vpe_id(&cpu_data[cpu]);



		pr_debug("Halting core %d VP%d\n", core, vpe_id);

		if (cpu_has_mipsmt) {

			/* Halt this TC */

			write_c0_tchalt(TCHALT_H);

			instruction_hazard();

		} else if (cpu_has_vp) {

			write_cpc_cl_vp_stop(1 << vpe_id);



			/* Ensure that the VP_STOP register is written */

			wmb();

		}

	} else {

		pr_debug("Gating power to core %d\n", core);

		/* Power down the core */

		cps_pm_enter_state(CPS_PM_POWER_GATED);

	}

	cps_shutdown_this_cpu(cpu_death);



	/* This should never be reached */

	panic("Failed to offline CPU %u", cpu);
@@ -593,6 +620,9 @@ static const struct plat_smp_ops cps_smp_ops = { 
	.cpu_disable		= cps_cpu_disable,

	.cpu_die		= cps_cpu_die,

#endif

#ifdef CONFIG_KEXEC

	.kexec_nonboot_cpu	= cps_kexec_nonboot_cpu,

#endif

};



bool mips_cps_smp_in_use(void)