1 files changed, 262 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
new file mode 100644
index 00000000000..50b9aad5e27
--- /dev/null
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -0,0 +1,262 @@
+/* linux/arch/arm/mach-exynos4/platsmp.c
+ *
+ * Copyright (c) 2010-2011 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 <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+#include <asm/firmware.h>
+
+#include "common.h"
+#include "regs-pmu.h"
+
+extern void exynos4_secondary_startup(void);
+
+static inline void __iomem *cpu_boot_reg_base(void)
+{
+	if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
+		return S5P_INFORM5;
+	return sysram_base_addr;
+}
+
+static inline void __iomem *cpu_boot_reg(int cpu)
+{
+	void __iomem *boot_reg;
+
+	boot_reg = cpu_boot_reg_base();
+	if (!boot_reg)
+		return ERR_PTR(-ENODEV);
+	if (soc_is_exynos4412())
+		boot_reg += 4*cpu;
+	else if (soc_is_exynos5420() || soc_is_exynos5800())
+		boot_reg += 4;
+	return boot_reg;
+}
+
+/*
+ * 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)
+{
+	return (void __iomem *)(S5P_VA_SCU);
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void exynos_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 exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	unsigned long timeout;
+	u32 mpidr = cpu_logical_map(cpu);
+	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	int ret = -ENOSYS;
+
+	/*
+	 * 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 core ID, whereas
+	 * "cpu" is Linux's internal ID.
+	 */
+	write_pen_release(core_id);
+
+	if (!exynos_cpu_power_state(core_id)) {
+		exynos_cpu_power_up(core_id);
+		timeout = 10;
+
+		/* wait max 10 ms until cpu1 is on */
+		while (exynos_cpu_power_state(core_id)
+		       != S5P_CORE_LOCAL_PWR_EN) {
+			if (timeout-- == 0)
+				break;
+
+			mdelay(1);
+		}
+
+		if (timeout == 0) {
+			printk(KERN_ERR "cpu1 power enable failed");
+			spin_unlock(&boot_lock);
+			return -ETIMEDOUT;
+		}
+	}
+	/*
+	 * 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.
+	 */
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		unsigned long boot_addr;
+
+		smp_rmb();
+
+		boot_addr = virt_to_phys(exynos4_secondary_startup);
+
+		/*
+		 * Try to set boot address using firmware first
+		 * and fall back to boot register if it fails.
+		 */
+		ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
+		if (ret && ret != -ENOSYS)
+			goto fail;
+		if (ret == -ENOSYS) {
+			void __iomem *boot_reg = cpu_boot_reg(core_id);
+
+			if (IS_ERR(boot_reg)) {
+				ret = PTR_ERR(boot_reg);
+				goto fail;
+			}
+			__raw_writel(boot_addr, cpu_boot_reg(core_id));
+		}
+
+		call_firmware_op(cpu_boot, core_id);
+
+		arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+		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
+	 */
+fail:
+	spin_unlock(&boot_lock);
+
+	return pen_release != -1 ? ret : 0;
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+
+static void __init exynos_smp_init_cpus(void)
+{
+	void __iomem *scu_base = scu_base_addr();
+	unsigned int i, ncores;
+
+	if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
+		ncores = scu_base ? scu_get_core_count(scu_base) : 1;
+	else
+		/*
+		 * CPU Nodes are passed thru DT and set_cpu_possible
+		 * is set by "arm_dt_init_cpu_maps".
+		 */
+		return;
+
+	/* 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 exynos_smp_prepare_cpus(unsigned int max_cpus)
+{
+	int i;
+
+	exynos_sysram_init();
+
+	if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
+		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.
+	 *
+	 * Try using firmware operation first and fall back to
+	 * boot register if it fails.
+	 */
+	for (i = 1; i < max_cpus; ++i) {
+		unsigned long boot_addr;
+		u32 mpidr;
+		u32 core_id;
+		int ret;
+
+		mpidr = cpu_logical_map(i);
+		core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+		boot_addr = virt_to_phys(exynos4_secondary_startup);
+
+		ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
+		if (ret && ret != -ENOSYS)
+			break;
+		if (ret == -ENOSYS) {
+			void __iomem *boot_reg = cpu_boot_reg(core_id);
+
+			if (IS_ERR(boot_reg))
+				break;
+			__raw_writel(boot_addr, cpu_boot_reg(core_id));
+		}
+	}
+}
+
+struct smp_operations exynos_smp_ops __initdata = {
+	.smp_init_cpus		= exynos_smp_init_cpus,
+	.smp_prepare_cpus	= exynos_smp_prepare_cpus,
+	.smp_secondary_init	= exynos_secondary_init,
+	.smp_boot_secondary	= exynos_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= exynos_cpu_die,
+#endif
+};