1 files changed, 172 insertions, 0 deletions

diff --git a/arch/arm/mach-exynos4/platsmp.c b/arch/arm/mach-exynos4/platsmp.c
new file mode 100644
index 000000000000..6d35878ec1aa
--- /dev/null
+++ b/arch/arm/mach-exynos4/platsmp.c
@@ -0,0 +1,172 @@
+/* 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_scu.h>
+#include <asm/unified.h>
+
+#include <mach/hardware.h>
+#include <mach/regs-clock.h>
+
+extern void exynos4_secondary_startup(void);
+
+/*
+ * control for which core is the next to come out of the secondary
+ * boot "holding pen"
+ */
+
+volatile int __cpuinitdata pen_release = -1;
+
+/*
+ * 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);
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+        /*
+         * 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_secondary_init(0);
+
+        /*
+         * 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);
+}
+
+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.
+         *
+         * Note that "pen_release" is the hardware CPU ID, whereas
+         * "cpu" is Linux's internal ID.
+         */
+        write_pen_release(cpu);
+
+        /*
+         * 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.
+         */
+        smp_cross_call(cpumask_of(cpu), 1);
+
+        timeout = jiffies + (1 * HZ);
+        while (time_before(jiffies, timeout)) {
+                smp_rmb();
+                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.
+ */
+
+void __init smp_init_cpus(void)
+{
+        void __iomem *scu_base = scu_base_addr();
+        unsigned int i, ncores;
+
+        ncores = scu_base ? scu_get_core_count(scu_base) : 1;
+
+        /* sanity check */
+        if (ncores > NR_CPUS) {
+                printk(KERN_WARNING
+                       "EXYNOS4: no. of cores (%d) greater than configured "
+                       "maximum of %d - clipping\n",
+                       ncores, NR_CPUS);
+                ncores = NR_CPUS;
+        }
+
+        for (i = 0; i < ncores; i++)
+                set_cpu_possible(i, true);
+}
+
+void __init platform_smp_prepare_cpus(unsigned int max_cpus)
+{
+        int i;
+
+        /*
+         * 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);
+
+        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.
+         */
+        __raw_writel(BSYM(virt_to_phys(exynos4_secondary_startup)), S5P_VA_SYSRAM);
+}