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-rw-r--r--arch/arm/mach-omap2/omap-smp.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
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+/*
+ * 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/smp.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <asm/hardware/gic.h>
+#include <asm/smp_scu.h>
+#include <mach/hardware.h>
+#include <mach/omap4-common.h>
+
+/* SCU base address */
+static void __iomem *scu_base;
+
+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);
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /*
+ * Set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ /*
+ * Update the AuxCoreBoot0 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
+ */
+ omap_modify_auxcoreboot0(0x200, 0xfffffdff);
+ flush_cache_all();
+ smp_wmb();
+ gic_raise_softirq(cpumask_of(cpu), 1);
+
+ /*
+ * 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
+ * AuxCoreBoot1 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
+ */
+ omap_auxcoreboot_addr(virt_to_phys(omap_secondary_startup));
+ smp_wmb();
+
+ /*
+ * Send a 'sev' to wake the secondary core from WFE.
+ * Drain the outstanding writes to memory
+ */
+ dsb_sev();
+ 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;
+
+ /* Never released */
+ scu_base = ioremap(OMAP44XX_SCU_BASE, SZ_256);
+ BUG_ON(!scu_base);
+
+ ncores = scu_get_core_count(scu_base);
+
+ /* sanity check */
+ 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;
+ }
+
+ for (i = 0; i < ncores; i++)
+ set_cpu_possible(i, true);
+
+ set_smp_cross_call(gic_raise_softirq);
+}
+
+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);
+
+ /*
+ * Initialise the SCU and wake up the secondary core using
+ * wakeup_secondary().
+ */
+ scu_enable(scu_base);
+ wakeup_secondary();
+}