// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com> * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com> * Copyright (C) 2002 ARM Ltd. * All Rights Reserved */ #include <linux/io.h> #include <linux/delay.h> #include <linux/of.h> #include <linux/of_address.h> #include <asm/cacheflush.h> #include <asm/cp15.h> #include <asm/smp_plat.h> #include <asm/smp_scu.h> extern void ox820_secondary_startup(void); static void __iomem *cpu_ctrl; static void __iomem *gic_cpu_ctrl; #define HOLDINGPEN_CPU_OFFSET 0xc8 #define HOLDINGPEN_LOCATION_OFFSET 0xc4 #define GIC_NCPU_OFFSET(cpu) (0x100 + (cpu)*0x100) #define GIC_CPU_CTRL 0x00 #define GIC_CPU_CTRL_ENABLE 1 int __init ox820_boot_secondary(unsigned int cpu, struct task_struct *idle) { /* * Write the address of secondary startup into the * system-wide flags register. The BootMonitor waits * until it receives a soft interrupt, and then the * secondary CPU branches to this address. */ writel(virt_to_phys(ox820_secondary_startup), cpu_ctrl + HOLDINGPEN_LOCATION_OFFSET); writel(cpu, cpu_ctrl + HOLDINGPEN_CPU_OFFSET); /* * Enable GIC cpu interface in CPU Interface Control Register */ writel(GIC_CPU_CTRL_ENABLE, gic_cpu_ctrl + GIC_NCPU_OFFSET(cpu) + GIC_CPU_CTRL); /* * Send the secondary CPU a soft interrupt, thereby causing * the boot monitor to read the system wide flags register, * and branch to the address found there. */ arch_send_wakeup_ipi_mask(cpumask_of(cpu)); return 0; } static void __init ox820_smp_prepare_cpus(unsigned int max_cpus) { struct device_node *np; void __iomem *scu_base; np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-scu"); scu_base = of_iomap(np, 0); of_node_put(np); if (!scu_base) return; /* Remap CPU Interrupt Interface Registers */ np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-gic"); gic_cpu_ctrl = of_iomap(np, 1); of_node_put(np); if (!gic_cpu_ctrl) goto unmap_scu; np = of_find_compatible_node(NULL, NULL, "oxsemi,ox820-sys-ctrl"); cpu_ctrl = of_iomap(np, 0); of_node_put(np); if (!cpu_ctrl) goto unmap_scu; scu_enable(scu_base); flush_cache_all(); unmap_scu: iounmap(scu_base); } static const struct smp_operations ox820_smp_ops __initconst = { .smp_prepare_cpus = ox820_smp_prepare_cpus, .smp_boot_secondary = ox820_boot_secondary, }; CPU_METHOD_OF_DECLARE(ox820_smp, "oxsemi,ox820-smp", &ox820_smp_ops);