2 * Copyright (C) 2002 ARM Ltd.
3 * Copyright (C) 2008 STMicroelctronics.
4 * Copyright (C) 2009 ST-Ericsson.
5 * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
7 * This file is based on arm realview platform
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/smp.h>
20 #include <asm/cacheflush.h>
21 #include <asm/localtimer.h>
22 #include <asm/smp_scu.h>
23 #include <mach/hardware.h>
26 * control for which core is the next to come out of the secondary
29 volatile int __cpuinitdata pen_release = -1;
31 static unsigned int __init get_core_count(void)
33 return scu_get_core_count(__io_address(UX500_SCU_BASE));
37 * Write pen_release in a way that is guaranteed to be visible to all
38 * observers, irrespective of whether they're taking part in coherency
39 * or not. This is necessary for the hotplug code to work reliably.
41 static void write_pen_release(int val)
45 __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
46 outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
49 static DEFINE_SPINLOCK(boot_lock);
51 void __cpuinit platform_secondary_init(unsigned int cpu)
56 * if any interrupts are already enabled for the primary
57 * core (e.g. timer irq), then they will not have been enabled
60 gic_cpu_init(0, __io_address(UX500_GIC_CPU_BASE));
63 * let the primary processor know we're out of the
64 * pen, then head off into the C entry point
66 write_pen_release(-1);
69 * Synchronise with the boot thread.
71 spin_lock(&boot_lock);
72 spin_unlock(&boot_lock);
75 int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
77 unsigned long timeout;
80 * set synchronisation state between this boot processor
81 * and the secondary one
83 spin_lock(&boot_lock);
86 * The secondary processor is waiting to be released from
87 * the holding pen - release it, then wait for it to flag
88 * that it has been released by resetting pen_release.
90 write_pen_release(cpu);
92 timeout = jiffies + (1 * HZ);
93 while (time_before(jiffies, timeout)) {
94 if (pen_release == -1)
99 * now the secondary core is starting up let it run its
100 * calibrations, then wait for it to finish
102 spin_unlock(&boot_lock);
104 return pen_release != -1 ? -ENOSYS : 0;
107 static void __init wakeup_secondary(void)
110 * write the address of secondary startup into the backup ram register
111 * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
112 * backup ram register at offset 0x1FF0, which is what boot rom code
113 * is waiting for. This would wake up the secondary core from WFE
115 #define U8500_CPU1_JUMPADDR_OFFSET 0x1FF4
116 __raw_writel(virt_to_phys(u8500_secondary_startup),
117 __io_address(UX500_BACKUPRAM0_BASE) +
118 U8500_CPU1_JUMPADDR_OFFSET);
120 #define U8500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
121 __raw_writel(0xA1FEED01,
122 __io_address(UX500_BACKUPRAM0_BASE) +
123 U8500_CPU1_WAKEMAGIC_OFFSET);
125 /* make sure write buffer is drained */
130 * Initialise the CPU possible map early - this describes the CPUs
131 * which may be present or become present in the system.
133 void __init smp_init_cpus(void)
135 unsigned int i, ncores = get_core_count();
137 for (i = 0; i < ncores; i++)
138 set_cpu_possible(i, true);
141 void __init smp_prepare_cpus(unsigned int max_cpus)
143 unsigned int ncores = get_core_count();
144 unsigned int cpu = smp_processor_id();
150 "U8500: strange CM count of 0? Default to 1\n");
154 if (ncores > num_possible_cpus()) {
156 "U8500: no. of cores (%d) greater than configured "
157 "maximum of %d - clipping\n",
158 ncores, num_possible_cpus());
159 ncores = num_possible_cpus();
162 smp_store_cpu_info(cpu);
165 * are we trying to boot more cores than exist?
167 if (max_cpus > ncores)
171 * Initialise the present map, which describes the set of CPUs
172 * actually populated at the present time.
174 for (i = 0; i < max_cpus; i++)
175 set_cpu_present(i, true);
179 * Enable the local timer or broadcast device for the
180 * boot CPU, but only if we have more than one CPU.
182 percpu_timer_setup();
183 scu_enable(__io_address(UX500_SCU_BASE));