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-rw-r--r--arch/arm/mach-ux500/platsmp.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
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+/*
+ * Copyright (C) 2002 ARM Ltd.
+ * Copyright (C) 2008 STMicroelctronics.
+ * Copyright (C) 2009 ST-Ericsson.
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ *
+ * This file is based on arm realview platform
+ *
+ * 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/smp.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <asm/localtimer.h>
+#include <asm/smp_scu.h>
+#include <mach/hardware.h>
+
+/*
+ * control for which core is the next to come out of the secondary
+ * boot "holding pen"
+ */
+volatile int __cpuinitdata pen_release = -1;
+
+static unsigned int __init get_core_count(void)
+{
+ return scu_get_core_count(__io_address(U8500_SCU_BASE));
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+ trace_hardirqs_off();
+
+ /*
+ * if any interrupts are already enabled for the primary
+ * core (e.g. timer irq), then they will not have been enabled
+ * for us: do so
+ */
+ gic_cpu_init(0, __io_address(U8500_GIC_CPU_BASE));
+
+ /*
+ * let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ pen_release = -1;
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+
+ /*
+ * 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.
+ */
+ pen_release = cpu;
+ flush_cache_all();
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ if (pen_release == -1)
+ break;
+ }
+
+ /*
+ * 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;
+}
+
+static void __init wakeup_secondary(void)
+{
+ /* nobody is to be released from the pen yet */
+ pen_release = -1;
+
+ /*
+ * write the address of secondary startup into the backup ram register
+ * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
+ * backup ram register at offset 0x1FF0, which is what boot rom code
+ * is waiting for. This would wake up the secondary core from WFE
+ */
+#define U8500_CPU1_JUMPADDR_OFFSET 0x1FF4
+ __raw_writel(virt_to_phys(u8500_secondary_startup),
+ (void __iomem *)IO_ADDRESS(U8500_BACKUPRAM0_BASE) +
+ U8500_CPU1_JUMPADDR_OFFSET);
+
+#define U8500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
+ __raw_writel(0xA1FEED01,
+ (void __iomem *)IO_ADDRESS(U8500_BACKUPRAM0_BASE) +
+ U8500_CPU1_WAKEMAGIC_OFFSET);
+
+ /* make sure write buffer is drained */
+ mb();
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+void __init smp_init_cpus(void)
+{
+ unsigned int i, ncores = get_core_count();
+
+ for (i = 0; i < ncores; i++)
+ set_cpu_possible(i, true);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int ncores = get_core_count();
+ unsigned int cpu = smp_processor_id();
+ int i;
+
+ /* sanity check */
+ if (ncores == 0) {
+ printk(KERN_ERR
+ "U8500: strange CM count of 0? Default to 1\n");
+ ncores = 1;
+ }
+
+ if (ncores > num_possible_cpus()) {
+ printk(KERN_WARNING
+ "U8500: no. of cores (%d) greater than configured "
+ "maximum of %d - clipping\n",
+ ncores, num_possible_cpus());
+ ncores = num_possible_cpus();
+ }
+
+ smp_store_cpu_info(cpu);
+
+ /*
+ * are we trying to boot more cores than exist?
+ */
+ if (max_cpus > ncores)
+ max_cpus = ncores;
+
+ /*
+ * Initialise the present map, which describes the set of CPUs
+ * actually populated at the present time.
+ */
+ for (i = 0; i < max_cpus; i++)
+ set_cpu_present(i, true);
+
+ if (max_cpus > 1) {
+ /*
+ * Enable the local timer or broadcast device for the
+ * boot CPU, but only if we have more than one CPU.
+ */
+ percpu_timer_setup();
+ scu_enable(__io_address(U8500_SCU_BASE));
+ wakeup_secondary();
+ }
+}