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Commit fbde2d7d authored by Qais Yousef's avatar Qais Yousef Committed by Thomas Gleixner
Browse files

MIPS: Add generic SMP IPI support 



Use the new generic IPI layer to provide generic SMP IPI support if the irqchip
supports it.

Signed-off-by: default avatarQais Yousef <qais.yousef@imgtec.com>
Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-17-git-send-email-qais.yousef@imgtec.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 78930f09

arch/mips/kernel/smp.c

+136 −0
Original line number Diff line number Diff line
@@ -33,12 +33,16 @@ 
#include <linux/cpu.h>

#include <linux/err.h>

#include <linux/ftrace.h>

#include <linux/irqdomain.h>

#include <linux/of.h>

#include <linux/of_irq.h>



#include <linux/atomic.h>

#include <asm/cpu.h>

#include <asm/processor.h>

#include <asm/idle.h>

#include <asm/r4k-timer.h>

#include <asm/mips-cpc.h>

#include <asm/mmu_context.h>

#include <asm/time.h>

#include <asm/setup.h>
@@ -79,6 +83,11 @@ static cpumask_t cpu_core_setup_map; 


cpumask_t cpu_coherent_mask;



#ifdef CONFIG_GENERIC_IRQ_IPI

static struct irq_desc *call_desc;

static struct irq_desc *sched_desc;

#endif



static inline void set_cpu_sibling_map(int cpu)

{

	int i;
@@ -145,6 +154,133 @@ void register_smp_ops(struct plat_smp_ops *ops) 
	mp_ops = ops;

}



#ifdef CONFIG_GENERIC_IRQ_IPI

void mips_smp_send_ipi_single(int cpu, unsigned int action)

{

	mips_smp_send_ipi_mask(cpumask_of(cpu), action);

}



void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)

{

	unsigned long flags;

	unsigned int core;

	int cpu;



	local_irq_save(flags);



	switch (action) {

	case SMP_CALL_FUNCTION:

		__ipi_send_mask(call_desc, mask);

		break;



	case SMP_RESCHEDULE_YOURSELF:

		__ipi_send_mask(sched_desc, mask);

		break;



	default:

		BUG();

	}



	if (mips_cpc_present()) {

		for_each_cpu(cpu, mask) {

			core = cpu_data[cpu].core;



			if (core == current_cpu_data.core)

				continue;



			while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {

				mips_cpc_lock_other(core);

				write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);

				mips_cpc_unlock_other();

			}

		}

	}



	local_irq_restore(flags);

}





static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)

{

	scheduler_ipi();



	return IRQ_HANDLED;

}



static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)

{

	generic_smp_call_function_interrupt();



	return IRQ_HANDLED;

}



static struct irqaction irq_resched = {

	.handler	= ipi_resched_interrupt,

	.flags		= IRQF_PERCPU,

	.name		= "IPI resched"

};



static struct irqaction irq_call = {

	.handler	= ipi_call_interrupt,

	.flags		= IRQF_PERCPU,

	.name		= "IPI call"

};



static __init void smp_ipi_init_one(unsigned int virq,

				    struct irqaction *action)

{

	int ret;



	irq_set_handler(virq, handle_percpu_irq);

	ret = setup_irq(virq, action);

	BUG_ON(ret);

}



static int __init mips_smp_ipi_init(void)

{

	unsigned int call_virq, sched_virq;

	struct irq_domain *ipidomain;

	struct device_node *node;



	node = of_irq_find_parent(of_root);

	ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);



	/*

	 * Some platforms have half DT setup. So if we found irq node but

	 * didn't find an ipidomain, try to search for one that is not in the

	 * DT.

	 */

	if (node && !ipidomain)

		ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);



	BUG_ON(!ipidomain);



	call_virq = irq_reserve_ipi(ipidomain, cpu_possible_mask);

	BUG_ON(!call_virq);



	sched_virq = irq_reserve_ipi(ipidomain, cpu_possible_mask);

	BUG_ON(!sched_virq);



	if (irq_domain_is_ipi_per_cpu(ipidomain)) {

		int cpu;



		for_each_cpu(cpu, cpu_possible_mask) {

			smp_ipi_init_one(call_virq + cpu, &irq_call);

			smp_ipi_init_one(sched_virq + cpu, &irq_resched);

		}

	} else {

		smp_ipi_init_one(call_virq, &irq_call);

		smp_ipi_init_one(sched_virq, &irq_resched);

	}



	call_desc = irq_to_desc(call_virq);

	sched_desc = irq_to_desc(sched_virq);



	return 0;

}

early_initcall(mips_smp_ipi_init);

#endif



/*

 * First C code run on the secondary CPUs after being started up by

 * the master.