From 5420b4b156179ec634d9e42279b6898b85852960 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Fri, 9 Oct 2015 13:38:57 +0200 Subject: ARM: realview: add an DT SMP boot method This adds an SMP boot method for the ARM RealView reference designs. We also select HAVE_SMP by default and make it use SMP_ON_UP so we only need to support one single kernel across the RealView reference designs when using DT. The RealViews need to have the SCU (Snoop Control Unit) activated on boot, and this is now done by looking up its address from the device tree and initializing it and counting the available cores. The RealViews boot by using a magic address register in the system controller (SYS_FLAGS) to store the boot address, the ROM will then read this register to the PC when the CPUs are taken out of WFI. This code uses a handle to the syscon regmap to access this register. Signed-off-by: Linus Walleij --- arch/arm/mach-realview/platsmp-dt.c | 91 +++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 arch/arm/mach-realview/platsmp-dt.c (limited to 'arch/arm/mach-realview/platsmp-dt.c') diff --git a/arch/arm/mach-realview/platsmp-dt.c b/arch/arm/mach-realview/platsmp-dt.c new file mode 100644 index 000000000000..65585392655b --- /dev/null +++ b/arch/arm/mach-realview/platsmp-dt.c @@ -0,0 +1,91 @@ +/* + * Copyright (C) 2015 Linus Walleij + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +#include "core.h" + +#define REALVIEW_SYS_FLAGSSET_OFFSET 0x30 + +static const struct of_device_id realview_scu_match[] = { + { .compatible = "arm,arm11mp-scu", }, + { .compatible = "arm,cortex-a9-scu", }, + { .compatible = "arm,cortex-a5-scu", }, + { } +}; + +static const struct of_device_id realview_syscon_match[] = { + { .compatible = "arm,core-module-integrator", }, + { .compatible = "arm,realview-eb-syscon", }, + { .compatible = "arm,realview-pb11mp-syscon", }, + { .compatible = "arm,realview-pbx-syscon", }, + { }, +}; + +static void __init realview_smp_prepare_cpus(unsigned int max_cpus) +{ + struct device_node *np; + void __iomem *scu_base; + struct regmap *map; + unsigned int ncores; + int i; + + np = of_find_matching_node(NULL, realview_scu_match); + if (!np) { + pr_err("PLATSMP: No SCU base address\n"); + return; + } + scu_base = of_iomap(np, 0); + of_node_put(np); + if (!scu_base) { + pr_err("PLATSMP: No SCU remap\n"); + return; + } + + scu_enable(scu_base); + ncores = scu_get_core_count(scu_base); + pr_info("SCU: %d cores detected\n", ncores); + for (i = 0; i < ncores; i++) + set_cpu_possible(i, true); + iounmap(scu_base); + + /* The syscon contains the magic SMP start address registers */ + np = of_find_matching_node(NULL, realview_syscon_match); + if (!np) { + pr_err("PLATSMP: No syscon match\n"); + return; + } + map = syscon_node_to_regmap(np); + if (IS_ERR(map)) { + pr_err("PLATSMP: No syscon regmap\n"); + return; + } + /* Put the boot address in this magic register */ + regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET, + virt_to_phys(versatile_secondary_startup)); +} + +struct smp_operations realview_dt_smp_ops __initdata = { + .smp_prepare_cpus = realview_smp_prepare_cpus, + .smp_secondary_init = versatile_secondary_init, + .smp_boot_secondary = versatile_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = realview_cpu_die, +#endif +}; +CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops); -- cgit