diff options
Diffstat (limited to 'arch/arm/mach-mvebu/platsmp-a9.c')
| -rw-r--r-- | arch/arm/mach-mvebu/platsmp-a9.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/arch/arm/mach-mvebu/platsmp-a9.c b/arch/arm/mach-mvebu/platsmp-a9.c new file mode 100644 index 000000000..785ee2af5 --- /dev/null +++ b/arch/arm/mach-mvebu/platsmp-a9.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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> + */ + +#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 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 const struct smp_operations mvebu_cortex_a9_smp_ops __initconst = { + .smp_boot_secondary = mvebu_cortex_a9_boot_secondary, +}; + +static const struct smp_operations armada_38x_smp_ops __initconst = { + .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); +CPU_METHOD_OF_DECLARE(mvebu_armada_390_smp, "marvell,armada-390-smp", + &armada_38x_smp_ops); |