+/*
+ * OMAP4 SMP source file. It contains platform specific fucntions
+ * needed for the linux smp kernel.
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ *
+ * Author:
+ * Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * Platform file needed for the OMAP4 SMP. This file is based on arm
+ * realview smp platform.
+ * * Copyright (c) 2002 ARM Limited.
+ *
+ * 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/device.h>
+#include <linux/jiffies.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+
+#include <asm/localtimer.h>
+#include <asm/smp_scu.h>
+#include <mach/hardware.h>
+
+/* Registers used for communicating startup information */
+#define OMAP4_AUXCOREBOOT_REG0 (OMAP44XX_VA_WKUPGEN_BASE + 0x800)
+#define OMAP4_AUXCOREBOOT_REG1 (OMAP44XX_VA_WKUPGEN_BASE + 0x804)
+
+/* SCU base address */
+static void __iomem *scu_base = OMAP44XX_VA_SCU_BASE;
+
+/*
+ * Use SCU config register to count number of cores
+ */
+static inline unsigned int get_core_count(void)
+{
+ if (scu_base)
+ return scu_get_core_count(scu_base);
+ return 1;
+}
+
+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(OMAP44XX_GIC_CPU_BASE));
+
+ /*
+ * 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);
+
+ /*
+ * Update the AuxCoreBoot1 with boot state for secondary core.
+ * omap_secondary_startup() routine will hold the secondary core till
+ * the AuxCoreBoot1 register is updated with cpu state
+ * A barrier is added to ensure that write buffer is drained
+ */
+ __raw_writel(cpu, OMAP4_AUXCOREBOOT_REG1);
+ smp_wmb();
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout))
+ ;
+
+ /*
+ * Now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return 0;
+}
+
+static void __init wakeup_secondary(void)
+{
+ /*
+ * Write the address of secondary startup routine into the
+ * AuxCoreBoot0 where ROM code will jump and start executing
+ * on secondary core once out of WFE
+ * A barrier is added to ensure that write buffer is drained
+ */
+ __raw_writel(virt_to_phys(omap_secondary_startup), \
+ OMAP4_AUXCOREBOOT_REG0);
+ smp_wmb();
+
+ /*
+ * Send a 'sev' to wake the secondary core from WFE.
+ */
+ set_event();
+ 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
+ "OMAP4: strange core count of 0? Default to 1\n");
+ ncores = 1;
+ }
+
+ if (ncores > NR_CPUS) {
+ printk(KERN_WARNING
+ "OMAP4: no. of cores (%d) greater than configured "
+ "maximum of %d - clipping\n",
+ ncores, NR_CPUS);
+ ncores = NR_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();
+
+ /*
+ * Initialise the SCU and wake up the secondary core using
+ * wakeup_secondary().
+ */
+ scu_enable(scu_base);
+ wakeup_secondary();
+ }
+}
git.openpandora.org / pandora-kernel.git / commitdiff