sh: add SMP support for J2 (b4214e41) · Commits · 戴 / test

arch/sh/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -261,6 +261,8 @@ config CPU_SUBTYPE_SH7619
		config CPU_SUBTYPE_J2
		bool "Support J2 processor"
		select CPU_J2
		select SYS_SUPPORTS_SMP
		select GENERIC_CLOCKEVENTS_BROADCAST if SMP

		# SH-2A Processor Support

arch/sh/kernel/cpu/sh2/Makefile

+4 −0

Original line number	Diff line number	Diff line
		@@ -5,3 +5,7 @@
		obj-y := ex.o probe.o entry.o

		obj-$(CONFIG_CPU_SUBTYPE_SH7619) += setup-sh7619.o clock-sh7619.o

		# SMP setup
		smp-$(CONFIG_CPU_J2) := smp-j2.o
		obj-$(CONFIG_SMP) += $(smp-y)

arch/sh/kernel/cpu/sh2/smp-j2.c

0 → 100644

+139 −0

Original line number	Diff line number	Diff line
		/*
		* SMP support for J2 processor
		*
		* Copyright (C) 2015-2016 Smart Energy Instruments, Inc.
		*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file "COPYING" in the main directory of this archive
		* for more details.
		*/

		#include <linux/smp.h>
		#include <linux/interrupt.h>
		#include <linux/io.h>
		#include <linux/of_address.h>
		#include <linux/of_irq.h>
		#include <asm/cmpxchg.h>

		DEFINE_PER_CPU(unsigned, j2_ipi_messages);

		extern u32 *sh2_cpuid_addr;
		static u32 *j2_ipi_trigger;
		static int j2_ipi_irq;

		static irqreturn_t j2_ipi_interrupt_handler(int irq, void *arg)
		{
		unsigned cpu = hard_smp_processor_id();
		volatile unsigned *pmsg = &per_cpu(j2_ipi_messages, cpu);
		unsigned messages, i;

		do messages = *pmsg;
		while (cmpxchg(pmsg, messages, 0) != messages);

		if (!messages) return IRQ_NONE;

		for (i=0; i<SMP_MSG_NR; i++)
		if (messages & (1U<<i))
		smp_message_recv(i);

		return IRQ_HANDLED;
		}

		static void j2_smp_setup(void)
		{
		}

		static void j2_prepare_cpus(unsigned int max_cpus)
		{
		struct device_node *np;
		unsigned i, max = 1;

		np = of_find_compatible_node(NULL, NULL, "jcore,ipi-controller");
		if (!np)
		goto out;

		j2_ipi_irq = irq_of_parse_and_map(np, 0);
		j2_ipi_trigger = of_iomap(np, 0);
		if (!j2_ipi_irq \|\| !j2_ipi_trigger)
		goto out;

		np = of_find_compatible_node(NULL, NULL, "jcore,cpuid-mmio");
		if (!np)
		goto out;

		sh2_cpuid_addr = of_iomap(np, 0);
		if (!sh2_cpuid_addr)
		goto out;

		if (request_irq(j2_ipi_irq, j2_ipi_interrupt_handler, IRQF_PERCPU,
		"ipi", (void *)j2_ipi_interrupt_handler) != 0)
		goto out;

		max = max_cpus;
		out:
		/* Disable any cpus past max_cpus, or all secondaries if we didn't
		* get the necessary resources to support SMP. */
		for (i=max; i<NR_CPUS; i++) {
		set_cpu_possible(i, false);
		set_cpu_present(i, false);
		}
		}

		static void j2_start_cpu(unsigned int cpu, unsigned long entry_point)
		{
		struct device_node *np;
		u32 regs[2];
		void __iomem release, initpc;

		if (!cpu) return;

		np = of_get_cpu_node(cpu, NULL);
		if (!np) return;

		if (of_property_read_u32_array(np, "cpu-release-addr", regs, 2)) return;
		release = ioremap_nocache(regs[0], sizeof(u32));
		initpc = ioremap_nocache(regs[1], sizeof(u32));

		__raw_writel(entry_point, initpc);
		__raw_writel(1, release);

		iounmap(initpc);
		iounmap(release);

		pr_info("J2 SMP: requested start of cpu %u\n", cpu);
		}

		static unsigned int j2_smp_processor_id(void)
		{
		return __raw_readl(sh2_cpuid_addr);
		}

		static void j2_send_ipi(unsigned int cpu, unsigned int message)
		{
		volatile unsigned *pmsg;
		unsigned old;
		unsigned long val;

		/* There is only one IPI interrupt shared by all messages, so
		* we keep a separate interrupt flag per message type in sw. */
		pmsg = &per_cpu(j2_ipi_messages, cpu);
		do old = *pmsg;
		while (cmpxchg(pmsg, old, old\|(1U<<message)) != old);

		/* Generate the actual interrupt by writing to CCRn bit 28. */
		val = __raw_readl(j2_ipi_trigger + cpu);
		__raw_writel(val \| (1U<<28), j2_ipi_trigger + cpu);
		}

		static struct plat_smp_ops j2_smp_ops = {
		.smp_setup = j2_smp_setup,
		.prepare_cpus = j2_prepare_cpus,
		.start_cpu = j2_start_cpu,
		.smp_processor_id = j2_smp_processor_id,
		.send_ipi = j2_send_ipi,
		.cpu_die = native_cpu_die,
		.cpu_disable = native_cpu_disable,
		.play_dead = native_play_dead,
		};

		CPU_METHOD_OF_DECLARE(j2_cpu_method, "jcore,spin-table", &j2_smp_ops);

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