| /* linux/arch/arm/mach-exynos4/platsmp.c |
| * |
| * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. |
| * http://www.samsung.com |
| * |
| * Cloned from linux/arch/arm/mach-vexpress/platsmp.c |
| * |
| * Copyright (C) 2002 ARM Ltd. |
| * All Rights Reserved |
| * |
| * 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 <linux/init.h> |
| #include <linux/errno.h> |
| #include <linux/delay.h> |
| #include <linux/device.h> |
| #include <linux/jiffies.h> |
| #include <linux/smp.h> |
| #include <linux/io.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/smp_plat.h> |
| #include <asm/smp_scu.h> |
| #include <asm/firmware.h> |
| |
| #include <mach/hardware.h> |
| #include <mach/regs-clock.h> |
| #include <mach/regs-pmu.h> |
| |
| #include <plat/cpu.h> |
| |
| #include "common.h" |
| |
| extern void exynos4_secondary_startup(void); |
| |
| static inline void __iomem *cpu_boot_reg_base(void) |
| { |
| if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1) |
| return S5P_INFORM5; |
| return S5P_VA_SYSRAM; |
| } |
| |
| static inline void __iomem *cpu_boot_reg(int cpu) |
| { |
| void __iomem *boot_reg; |
| |
| boot_reg = cpu_boot_reg_base(); |
| if (soc_is_exynos4412()) |
| boot_reg += 4*cpu; |
| return boot_reg; |
| } |
| |
| /* |
| * Write pen_release in a way that is guaranteed to be visible to all |
| * observers, irrespective of whether they're taking part in coherency |
| * or not. This is necessary for the hotplug code to work reliably. |
| */ |
| static void write_pen_release(int val) |
| { |
| pen_release = val; |
| smp_wmb(); |
| __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); |
| outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); |
| } |
| |
| static void __iomem *scu_base_addr(void) |
| { |
| return (void __iomem *)(S5P_VA_SCU); |
| } |
| |
| static DEFINE_SPINLOCK(boot_lock); |
| |
| static void __cpuinit exynos_secondary_init(unsigned int cpu) |
| { |
| /* |
| * let the primary processor know we're out of the |
| * pen, then head off into the C entry point |
| */ |
| write_pen_release(-1); |
| |
| /* |
| * Synchronise with the boot thread. |
| */ |
| spin_lock(&boot_lock); |
| spin_unlock(&boot_lock); |
| } |
| |
| static int __cpuinit exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) |
| { |
| unsigned long timeout; |
| unsigned long phys_cpu = cpu_logical_map(cpu); |
| |
| /* |
| * Set synchronisation state between this boot processor |
| * and the secondary one |
| */ |
| spin_lock(&boot_lock); |
| |
| /* |
| * The secondary processor is waiting to be released from |
| * the holding pen - release it, then wait for it to flag |
| * that it has been released by resetting pen_release. |
| * |
| * Note that "pen_release" is the hardware CPU ID, whereas |
| * "cpu" is Linux's internal ID. |
| */ |
| write_pen_release(phys_cpu); |
| |
| if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN)) { |
| __raw_writel(S5P_CORE_LOCAL_PWR_EN, |
| S5P_ARM_CORE1_CONFIGURATION); |
| |
| timeout = 10; |
| |
| /* wait max 10 ms until cpu1 is on */ |
| while ((__raw_readl(S5P_ARM_CORE1_STATUS) |
| & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN) { |
| if (timeout-- == 0) |
| break; |
| |
| mdelay(1); |
| } |
| |
| if (timeout == 0) { |
| printk(KERN_ERR "cpu1 power enable failed"); |
| spin_unlock(&boot_lock); |
| return -ETIMEDOUT; |
| } |
| } |
| /* |
| * 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. |
| */ |
| |
| timeout = jiffies + (1 * HZ); |
| while (time_before(jiffies, timeout)) { |
| unsigned long boot_addr; |
| |
| smp_rmb(); |
| |
| boot_addr = virt_to_phys(exynos4_secondary_startup); |
| |
| /* |
| * Try to set boot address using firmware first |
| * and fall back to boot register if it fails. |
| */ |
| if (call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr)) |
| __raw_writel(boot_addr, cpu_boot_reg(phys_cpu)); |
| |
| call_firmware_op(cpu_boot, phys_cpu); |
| |
| arch_send_wakeup_ipi_mask(cpumask_of(cpu)); |
| |
| if (pen_release == -1) |
| break; |
| |
| udelay(10); |
| } |
| |
| /* |
| * now the secondary core is starting up let it run its |
| * calibrations, then wait for it to finish |
| */ |
| spin_unlock(&boot_lock); |
| |
| return pen_release != -1 ? -ENOSYS : 0; |
| } |
| |
| /* |
| * Initialise the CPU possible map early - this describes the CPUs |
| * which may be present or become present in the system. |
| */ |
| |
| static void __init exynos_smp_init_cpus(void) |
| { |
| void __iomem *scu_base = scu_base_addr(); |
| unsigned int i, ncores; |
| |
| if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9) |
| ncores = scu_base ? scu_get_core_count(scu_base) : 1; |
| else |
| /* |
| * CPU Nodes are passed thru DT and set_cpu_possible |
| * is set by "arm_dt_init_cpu_maps". |
| */ |
| return; |
| |
| /* sanity check */ |
| if (ncores > nr_cpu_ids) { |
| pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", |
| ncores, nr_cpu_ids); |
| ncores = nr_cpu_ids; |
| } |
| |
| for (i = 0; i < ncores; i++) |
| set_cpu_possible(i, true); |
| } |
| |
| static void __init exynos_smp_prepare_cpus(unsigned int max_cpus) |
| { |
| int i; |
| |
| if (!(soc_is_exynos5250() || soc_is_exynos5440())) |
| scu_enable(scu_base_addr()); |
| |
| /* |
| * 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. |
| * |
| * Try using firmware operation first and fall back to |
| * boot register if it fails. |
| */ |
| for (i = 1; i < max_cpus; ++i) { |
| unsigned long phys_cpu; |
| unsigned long boot_addr; |
| |
| phys_cpu = cpu_logical_map(i); |
| boot_addr = virt_to_phys(exynos4_secondary_startup); |
| |
| if (call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr)) |
| __raw_writel(boot_addr, cpu_boot_reg(phys_cpu)); |
| } |
| } |
| |
| struct smp_operations exynos_smp_ops __initdata = { |
| .smp_init_cpus = exynos_smp_init_cpus, |
| .smp_prepare_cpus = exynos_smp_prepare_cpus, |
| .smp_secondary_init = exynos_secondary_init, |
| .smp_boot_secondary = exynos_boot_secondary, |
| #ifdef CONFIG_HOTPLUG_CPU |
| .cpu_die = exynos_cpu_die, |
| #endif |
| }; |