platsmp-a9.rar_A9 SMP_smp

/* * Symmetric Multi Processing (SMP) support for Marvell EBU Cortex-A9 * based SOCs (Armada 375/38x). * * Copyright (C) 2014 Marvell * * Gregory CLEMENT <gregory.clement@free-electrons.com> * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/init.h> #include <linux/io.h> #include <linux/of.h> #include <linux/smp.h> #include <linux/mbus.h> #include <asm/smp_scu.h> #include <asm/smp_plat.h> #include "common.h" #include "pmsu.h" extern void mvebu_cortex_a9_secondary_startup(void); static int __cpuinit mvebu_cortex_a9_boot_secondary(unsigned int cpu, struct task_struct *idle) { int ret, hw_cpu; pr_info("Booting CPU %d\n", cpu); /* * Write the address of secondary startup into the system-wide * flags register. The boot monitor waits until it receives a * soft interrupt, and then the secondary CPU branches to this * address. */ hw_cpu = cpu_logical_map(cpu); if (of_machine_is_compatible("marvell,armada375")) mvebu_system_controller_set_cpu_boot_addr(mvebu_cortex_a9_secondary_startup); else mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cortex_a9_secondary_startup); smp_wmb(); /* * Doing this before deasserting the CPUs is needed to wake up CPUs * in the offline state after using CPU hotplug. */ arch_send_wakeup_ipi_mask(cpumask_of(cpu)); ret = mvebu_cpu_reset_deassert(hw_cpu); if (ret) { pr_err("Could not start the secondary CPU: %d\n", ret); return ret; } return 0; } /* * When a CPU is brought back online, either through CPU hotplug, or * because of the boot of a kexec'ed kernel, the PMSU configuration * for this CPU might be in the deep idle state, preventing this CPU * from receiving interrupts. Here, we therefore take out the current * CPU from this state, which was entered by armada_38x_cpu_die() * below. */ static void armada_38x_secondary_init(unsigned int cpu) { mvebu_v7_pmsu_idle_exit(); } #ifdef CONFIG_HOTPLUG_CPU static void armada_38x_cpu_die(unsigned int cpu) { /* * CPU hotplug is implemented by putting offline CPUs into the * deep idle sleep state. */ armada_38x_do_cpu_suspend(true); } /* * We need a dummy function, so that platform_can_cpu_hotplug() knows * we support CPU hotplug. However, the function does not need to do * anything, because CPUs going offline can enter the deep idle state * by themselves, without any help from a still alive CPU. */ static int armada_38x_cpu_kill(unsigned int cpu) { return 1; } #endif static struct smp_operations mvebu_cortex_a9_smp_ops __initdata = { .smp_boot_secondary = mvebu_cortex_a9_boot_secondary, }; static struct smp_operations armada_38x_smp_ops __initdata = { .smp_boot_secondary = mvebu_cortex_a9_boot_secondary, .smp_secondary_init = armada_38x_secondary_init, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = armada_38x_cpu_die, .cpu_kill = armada_38x_cpu_kill, #endif }; CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp", &mvebu_cortex_a9_smp_ops); CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp", &armada_38x_smp_ops);