ARM: S5PV310: Add new CPU initialization support

This patch adds Samsung S5PV310/S5PC210 CPU support.
The S5PV310/S5PC210 integrates a ARM Cortex A9 multi-core.

Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Jongpill Lee <boyko.lee@samsung.com>
Signed-off-by: Jiseong Oh <jiseong.oh@samsung.com>
[kgene.kim@samsung.com: fix build errors]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 192 insertions, 0 deletions

diff --git a/arch/arm/mach-s5pv310/platsmp.c b/arch/arm/mach-s5pv310/platsmp.c
new file mode 100644
index 00000000000..fe9469abd00
--- /dev/null
+++ b/arch/arm/mach-s5pv310/platsmp.c
@@ -0,0 +1,192 @@
+/* linux/arch/arm/mach-s5pv310/platsmp.c
+ *
+ * Copyright (c) 2010 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/localtimer.h>
+#include <asm/smp_scu.h>
+#include <asm/unified.h>
+
+#include <mach/hardware.h>
+#include <mach/regs-clock.h>
+
+extern void s5pv310_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;
+
+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)
+{
+	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, gic_cpu_base_addr);
+
+	/*
+	 * let the primary processor know we're out of the
+	 * pen, then head off into the C entry point
+	 */
+	pen_release = -1;
+	smp_wmb();
+
+	/*
+	 * 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.
+	 */
+	pen_release = cpu;
+	__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
+	outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+
+	/*
+	 * 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));
+
+	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 == 0) {
+		printk(KERN_ERR
+		       "S5PV310: strange CM count of 0? Default to 1\n");
+
+		ncores = 1;
+	}
+
+	if (ncores > NR_CPUS) {
+		printk(KERN_WARNING
+		       "S5PV310: 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 smp_prepare_cpus(unsigned int max_cpus)
+{
+	unsigned int ncores = num_possible_cpus();
+	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.
+	 */
+	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(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(s5pv310_secondary_startup)), S5P_INFORM0);
+	}
+}