[ARM] tegra: SMP support

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>

1 files changed, 156 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
new file mode 100644
index 000000000000..1c0fd92cab39
--- /dev/null
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -0,0 +1,156 @@
+/*
+ *  linux/arch/arm/mach-tegra/platsmp.c
+ *
+ *  Copyright (C) 2002 ARM Ltd.
+ *  All Rights Reserved
+ *
+ *  Copyright (C) 2009 Palm
+ *  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 <mach/hardware.h>
+#include <asm/mach-types.h>
+#include <asm/localtimer.h>
+#include <asm/smp_scu.h>
+
+#include <mach/iomap.h>
+
+extern void tegra_secondary_startup(void);
+
+static DEFINE_SPINLOCK(boot_lock);
+static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
+
+#define EVP_CPU_RESET_VECTOR \
+	(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
+#define CLK_RST_CONTROLLER_CLK_CPU_CMPLX \
+	(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x4c)
+#define CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR \
+	(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x344)
+
+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(TEGRA_ARM_PERIF_BASE) + 0x100);
+
+	/*
+	 * 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 old_boot_vector;
+	unsigned long boot_vector;
+	unsigned long timeout;
+	u32 reg;
+
+	/*
+	 * set synchronisation state between this boot processor
+	 * and the secondary one
+	 */
+	spin_lock(&boot_lock);
+
+
+	/* set the reset vector to point to the secondary_startup routine */
+
+	boot_vector = virt_to_phys(tegra_secondary_startup);
+	old_boot_vector = readl(EVP_CPU_RESET_VECTOR);
+	writel(boot_vector, EVP_CPU_RESET_VECTOR);
+
+	/* enable cpu clock on cpu1 */
+	reg = readl(CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+	writel(reg & ~(1<<9), CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
+
+	reg = (1<<13) | (1<<9) | (1<<5) | (1<<1);
+	writel(reg, CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR);
+
+	smp_wmb();
+	flush_cache_all();
+
+	/* unhalt the cpu */
+	writel(0, IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + 0x14);
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		if (readl(EVP_CPU_RESET_VECTOR) != boot_vector)
+			break;
+		udelay(10);
+	}
+
+	/* put the old boot vector back */
+	writel(old_boot_vector, EVP_CPU_RESET_VECTOR);
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+	spin_unlock(&boot_lock);
+
+	return 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)
+{
+	unsigned int i, ncores = scu_get_core_count(scu_base);
+
+	for (i = 0; i < ncores; i++)
+		cpu_set(i, cpu_possible_map);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+	unsigned int ncores = scu_get_core_count(scu_base);
+	unsigned int cpu = smp_processor_id();
+	int i;
+
+	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);
+
+	/*
+	 * Initialise the SCU if there are more than one CPU and let
+	 * them know where to start. Note that, on modern versions of
+	 * MILO, the "poke" doesn't actually do anything until each
+	 * individual core is sent a soft interrupt to get it out of
+	 * WFI
+	 */
+	if (max_cpus > 1) {
+		percpu_timer_setup();
+		scu_enable(scu_base);
+	}
+}