1 /* linux/arch/arm/mach-exynos4/platsmp.c
3 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com
6 * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
8 * Copyright (C) 2002 ARM Ltd.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/init.h>
17 #include <linux/errno.h>
18 #include <linux/delay.h>
19 #include <linux/device.h>
20 #include <linux/jiffies.h>
21 #include <linux/smp.h>
23 #include <linux/irqchip/arm-gic.h>
25 #include <asm/cacheflush.h>
26 #include <asm/smp_plat.h>
27 #include <asm/smp_scu.h>
28 #include <asm/firmware.h>
30 #include <mach/hardware.h>
31 #include <mach/regs-clock.h>
32 #include <mach/regs-pmu.h>
38 extern void exynos4_secondary_startup(void);
40 static inline void __iomem *cpu_boot_reg_base(void)
42 if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
47 static inline void __iomem *cpu_boot_reg(int cpu)
49 void __iomem *boot_reg;
51 boot_reg = cpu_boot_reg_base();
52 if (soc_is_exynos4412())
58 * Write pen_release in a way that is guaranteed to be visible to all
59 * observers, irrespective of whether they're taking part in coherency
60 * or not. This is necessary for the hotplug code to work reliably.
62 static void write_pen_release(int val)
66 __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
67 outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
70 static void __iomem *scu_base_addr(void)
72 return (void __iomem *)(S5P_VA_SCU);
75 static DEFINE_SPINLOCK(boot_lock);
77 static void __cpuinit exynos_secondary_init(unsigned int cpu)
80 * if any interrupts are already enabled for the primary
81 * core (e.g. timer irq), then they will not have been enabled
84 gic_secondary_init(0);
87 * let the primary processor know we're out of the
88 * pen, then head off into the C entry point
90 write_pen_release(-1);
93 * Synchronise with the boot thread.
95 spin_lock(&boot_lock);
96 spin_unlock(&boot_lock);
99 static int __cpuinit exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
101 unsigned long timeout;
102 unsigned long phys_cpu = cpu_logical_map(cpu);
105 * Set synchronisation state between this boot processor
106 * and the secondary one
108 spin_lock(&boot_lock);
111 * The secondary processor is waiting to be released from
112 * the holding pen - release it, then wait for it to flag
113 * that it has been released by resetting pen_release.
115 * Note that "pen_release" is the hardware CPU ID, whereas
116 * "cpu" is Linux's internal ID.
118 write_pen_release(phys_cpu);
120 if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN)) {
121 __raw_writel(S5P_CORE_LOCAL_PWR_EN,
122 S5P_ARM_CORE1_CONFIGURATION);
126 /* wait max 10 ms until cpu1 is on */
127 while ((__raw_readl(S5P_ARM_CORE1_STATUS)
128 & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN) {
136 printk(KERN_ERR "cpu1 power enable failed");
137 spin_unlock(&boot_lock);
142 * Send the secondary CPU a soft interrupt, thereby causing
143 * the boot monitor to read the system wide flags register,
144 * and branch to the address found there.
147 timeout = jiffies + (1 * HZ);
148 while (time_before(jiffies, timeout)) {
149 unsigned long boot_addr;
153 boot_addr = virt_to_phys(exynos4_secondary_startup);
156 * Try to set boot address using firmware first
157 * and fall back to boot register if it fails.
159 if (call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr))
160 __raw_writel(boot_addr, cpu_boot_reg(phys_cpu));
162 call_firmware_op(cpu_boot, phys_cpu);
164 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
166 if (pen_release == -1)
173 * now the secondary core is starting up let it run its
174 * calibrations, then wait for it to finish
176 spin_unlock(&boot_lock);
178 return pen_release != -1 ? -ENOSYS : 0;
182 * Initialise the CPU possible map early - this describes the CPUs
183 * which may be present or become present in the system.
186 static void __init exynos_smp_init_cpus(void)
188 void __iomem *scu_base = scu_base_addr();
189 unsigned int i, ncores;
191 if (soc_is_exynos5250())
194 ncores = scu_base ? scu_get_core_count(scu_base) : 1;
197 if (ncores > nr_cpu_ids) {
198 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
203 for (i = 0; i < ncores; i++)
204 set_cpu_possible(i, true);
207 static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
211 if (!(soc_is_exynos5250() || soc_is_exynos5440()))
212 scu_enable(scu_base_addr());
215 * Write the address of secondary startup into the
216 * system-wide flags register. The boot monitor waits
217 * until it receives a soft interrupt, and then the
218 * secondary CPU branches to this address.
220 * Try using firmware operation first and fall back to
221 * boot register if it fails.
223 for (i = 1; i < max_cpus; ++i) {
224 unsigned long phys_cpu;
225 unsigned long boot_addr;
227 phys_cpu = cpu_logical_map(i);
228 boot_addr = virt_to_phys(exynos4_secondary_startup);
230 if (call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr))
231 __raw_writel(boot_addr, cpu_boot_reg(phys_cpu));
235 struct smp_operations exynos_smp_ops __initdata = {
236 .smp_init_cpus = exynos_smp_init_cpus,
237 .smp_prepare_cpus = exynos_smp_prepare_cpus,
238 .smp_secondary_init = exynos_secondary_init,
239 .smp_boot_secondary = exynos_boot_secondary,
240 #ifdef CONFIG_HOTPLUG_CPU
241 .cpu_die = exynos_cpu_die,