2 * linux/arch/arm/mach-realview/platsmp.c
4 * Copyright (C) 2002 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/jiffies.h>
16 #include <linux/smp.h>
19 #include <asm/cacheflush.h>
20 #include <mach/hardware.h>
21 #include <asm/mach-types.h>
22 #include <asm/localtimer.h>
24 #include <mach/board-eb.h>
25 #include <mach/board-pb11mp.h>
30 extern void realview_secondary_startup(void);
33 * control for which core is the next to come out of the secondary
36 volatile int __cpuinitdata pen_release = -1;
38 static void __iomem *scu_base_addr(void)
40 if (machine_is_realview_eb_mp())
41 return __io_address(REALVIEW_EB11MP_SCU_BASE);
42 else if (machine_is_realview_pb11mp())
43 return __io_address(REALVIEW_TC11MP_SCU_BASE);
45 return (void __iomem *)0;
48 static unsigned int __init get_core_count(void)
51 void __iomem *scu_base = scu_base_addr();
54 ncores = __raw_readl(scu_base + SCU_CONFIG);
55 ncores = (ncores & 0x03) + 1;
65 static void scu_enable(void)
68 void __iomem *scu_base = scu_base_addr();
70 scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
72 __raw_writel(scu_ctrl, scu_base + SCU_CTRL);
75 static DEFINE_SPINLOCK(boot_lock);
77 void __cpuinit platform_secondary_init(unsigned int cpu)
82 * if any interrupts are already enabled for the primary
83 * core (e.g. timer irq), then they will not have been enabled
86 gic_cpu_init(0, gic_cpu_base_addr);
89 * let the primary processor know we're out of the
90 * pen, then head off into the C entry point
96 * Synchronise with the boot thread.
98 spin_lock(&boot_lock);
99 spin_unlock(&boot_lock);
102 int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
104 unsigned long timeout;
107 * set synchronisation state between this boot processor
108 * and the secondary one
110 spin_lock(&boot_lock);
113 * The secondary processor is waiting to be released from
114 * the holding pen - release it, then wait for it to flag
115 * that it has been released by resetting pen_release.
117 * Note that "pen_release" is the hardware CPU ID, whereas
118 * "cpu" is Linux's internal ID.
126 * This is a later addition to the booting protocol: the
127 * bootMonitor now puts secondary cores into WFI, so
128 * poke_milo() no longer gets the cores moving; we need
129 * to send a soft interrupt to wake the secondary core.
130 * Use smp_cross_call() for this, since there's little
131 * point duplicating the code here
133 smp_cross_call(cpumask_of(cpu));
135 timeout = jiffies + (1 * HZ);
136 while (time_before(jiffies, timeout)) {
138 if (pen_release == -1)
145 * now the secondary core is starting up let it run its
146 * calibrations, then wait for it to finish
148 spin_unlock(&boot_lock);
150 return pen_release != -1 ? -ENOSYS : 0;
153 static void __init poke_milo(void)
155 extern void secondary_startup(void);
157 /* nobody is to be released from the pen yet */
161 * write the address of secondary startup into the system-wide
162 * flags register, then clear the bottom two bits, which is what
163 * BootMonitor is waiting for
166 #define REALVIEW_SYS_FLAGSS_OFFSET 0x30
167 __raw_writel(virt_to_phys(realview_secondary_startup),
168 __io_address(REALVIEW_SYS_BASE) +
169 REALVIEW_SYS_FLAGSS_OFFSET);
170 #define REALVIEW_SYS_FLAGSC_OFFSET 0x34
172 __io_address(REALVIEW_SYS_BASE) +
173 REALVIEW_SYS_FLAGSC_OFFSET);
180 * Initialise the CPU possible map early - this describes the CPUs
181 * which may be present or become present in the system.
183 void __init smp_init_cpus(void)
185 unsigned int i, ncores = get_core_count();
187 for (i = 0; i < ncores; i++)
188 cpu_set(i, cpu_possible_map);
191 void __init smp_prepare_cpus(unsigned int max_cpus)
193 unsigned int ncores = get_core_count();
194 unsigned int cpu = smp_processor_id();
200 "Realview: strange CM count of 0? Default to 1\n");
205 if (ncores > NR_CPUS) {
207 "Realview: no. of cores (%d) greater than configured "
208 "maximum of %d - clipping\n",
213 smp_store_cpu_info(cpu);
216 * are we trying to boot more cores than exist?
218 if (max_cpus > ncores)
222 * Initialise the present map, which describes the set of CPUs
223 * actually populated at the present time.
225 for (i = 0; i < max_cpus; i++)
226 cpu_set(i, cpu_present_map);
229 * Initialise the SCU if there are more than one CPU and let
230 * them know where to start. Note that, on modern versions of
231 * MILO, the "poke" doesn't actually do anything until each
232 * individual core is sent a soft interrupt to get it out of
237 * Enable the local timer or broadcast device for the
238 * boot CPU, but only if we have more than one CPU.
240 percpu_timer_setup();