Initial import

1 files changed, 169 insertions, 0 deletions

diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
new file mode 100644
index 000000000..a44967f31
--- /dev/null
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2002 ARM Ltd.
+ * Copyright (C) 2008 STMicroelctronics.
+ * Copyright (C) 2009 ST-Ericsson.
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ *
+ * This file is based on arm realview platform
+ *
+ * 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/smp.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#include "setup.h"
+
+#include "db8500-regs.h"
+#include "id.h"
+
+/* This is called from headsmp.S to wakeup the secondary core */
+extern void u8500_secondary_startup(void);
+
+/*
+ * 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();
+	sync_cache_w(&pen_release);
+}
+
+static void __iomem *scu_base_addr(void)
+{
+	if (cpu_is_u8500_family() || cpu_is_ux540_family())
+		return __io_address(U8500_SCU_BASE);
+	else
+		ux500_unknown_soc();
+
+	return NULL;
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void ux500_secondary_init(unsigned int cpu)
+{
+	/*
+	 * 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);
+}
+
+static int ux500_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.
+	 */
+	write_pen_release(cpu_logical_map(cpu));
+
+	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		if (pen_release == -1)
+			break;
+	}
+
+	/*
+	 * 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;
+}
+
+static void __init wakeup_secondary(void)
+{
+	void __iomem *backupram;
+
+	if (cpu_is_u8500_family() || cpu_is_ux540_family())
+		backupram = __io_address(U8500_BACKUPRAM0_BASE);
+	else
+		ux500_unknown_soc();
+
+	/*
+	 * write the address of secondary startup into the backup ram register
+	 * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
+	 * backup ram register at offset 0x1FF0, which is what boot rom code
+	 * is waiting for. This would wake up the secondary core from WFE
+	 */
+#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
+	__raw_writel(virt_to_phys(u8500_secondary_startup),
+		     backupram + UX500_CPU1_JUMPADDR_OFFSET);
+
+#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
+	__raw_writel(0xA1FEED01,
+		     backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
+
+	/* make sure write buffer is drained */
+	mb();
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+static void __init ux500_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_cpu_ids) {
+		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
+			ncores, nr_cpu_ids);
+		ncores = nr_cpu_ids;
+	}
+
+	for (i = 0; i < ncores; i++)
+		set_cpu_possible(i, true);
+}
+
+static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
+{
+
+	scu_enable(scu_base_addr());
+	wakeup_secondary();
+}
+
+struct smp_operations ux500_smp_ops __initdata = {
+	.smp_init_cpus		= ux500_smp_init_cpus,
+	.smp_prepare_cpus	= ux500_smp_prepare_cpus,
+	.smp_secondary_init	= ux500_secondary_init,
+	.smp_boot_secondary	= ux500_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= ux500_cpu_die,
+#endif
+};