1 files changed, 452 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
new file mode 100644
index 000000000..d7fedbb2e
--- /dev/null
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+// 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
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/soc/samsung/exynos-regs-pmu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+#include <asm/firmware.h>
+
+#include "common.h"
+
+extern void exynos4_secondary_startup(void);
+
+/* XXX exynos_pen_release is cargo culted code - DO NOT COPY XXX */
+volatile int exynos_pen_release = -1;
+
+#ifdef CONFIG_HOTPLUG_CPU
+static inline void cpu_leave_lowpower(u32 core_id)
+{
+	unsigned int v;
+
+	asm volatile(
+	"mrc	p15, 0, %0, c1, c0, 0\n"
+	"	orr	%0, %0, %1\n"
+	"	mcr	p15, 0, %0, c1, c0, 0\n"
+	"	mrc	p15, 0, %0, c1, c0, 1\n"
+	"	orr	%0, %0, %2\n"
+	"	mcr	p15, 0, %0, c1, c0, 1\n"
+	  : "=&r" (v)
+	  : "Ir" (CR_C), "Ir" (0x40)
+	  : "cc");
+}
+
+static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
+{
+	u32 mpidr = cpu_logical_map(cpu);
+	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+	for (;;) {
+
+		/* Turn the CPU off on next WFI instruction. */
+		exynos_cpu_power_down(core_id);
+
+		wfi();
+
+		if (exynos_pen_release == core_id) {
+			/*
+			 * OK, proper wakeup, we're done
+			 */
+			break;
+		}
+
+		/*
+		 * Getting here, means that we have come out of WFI without
+		 * having been woken up - this shouldn't happen
+		 *
+		 * Just note it happening - when we're woken, we can report
+		 * its occurrence.
+		 */
+		(*spurious)++;
+	}
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+/**
+ * exynos_core_power_down : power down the specified cpu
+ * @cpu : the cpu to power down
+ *
+ * Power down the specified cpu. The sequence must be finished by a
+ * call to cpu_do_idle()
+ *
+ */
+void exynos_cpu_power_down(int cpu)
+{
+	u32 core_conf;
+
+	if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
+		/*
+		 * Bypass power down for CPU0 during suspend. Check for
+		 * the SYS_PWR_REG value to decide if we are suspending
+		 * the system.
+		 */
+		int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+
+		if (!(val & S5P_CORE_LOCAL_PWR_EN))
+			return;
+	}
+
+	core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu));
+	core_conf &= ~S5P_CORE_LOCAL_PWR_EN;
+	pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
+}
+
+/**
+ * exynos_cpu_power_up : power up the specified cpu
+ * @cpu : the cpu to power up
+ *
+ * Power up the specified cpu
+ */
+void exynos_cpu_power_up(int cpu)
+{
+	u32 core_conf = S5P_CORE_LOCAL_PWR_EN;
+
+	if (soc_is_exynos3250())
+		core_conf |= S5P_CORE_AUTOWAKEUP_EN;
+
+	pmu_raw_writel(core_conf,
+			EXYNOS_ARM_CORE_CONFIGURATION(cpu));
+}
+
+/**
+ * exynos_cpu_power_state : returns the power state of the cpu
+ * @cpu : the cpu to retrieve the power state from
+ *
+ */
+int exynos_cpu_power_state(int cpu)
+{
+	return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
+			S5P_CORE_LOCAL_PWR_EN);
+}
+
+/**
+ * exynos_cluster_power_down : power down the specified cluster
+ * @cluster : the cluster to power down
+ */
+void exynos_cluster_power_down(int cluster)
+{
+	pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
+}
+
+/**
+ * exynos_cluster_power_up : power up the specified cluster
+ * @cluster : the cluster to power up
+ */
+void exynos_cluster_power_up(int cluster)
+{
+	pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
+			EXYNOS_COMMON_CONFIGURATION(cluster));
+}
+
+/**
+ * exynos_cluster_power_state : returns the power state of the cluster
+ * @cluster : the cluster to retrieve the power state from
+ *
+ */
+int exynos_cluster_power_state(int cluster)
+{
+	return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
+		S5P_CORE_LOCAL_PWR_EN);
+}
+
+/**
+ * exynos_scu_enable : enables SCU for Cortex-A9 based system
+ */
+void exynos_scu_enable(void)
+{
+	struct device_node *np;
+	static void __iomem *scu_base;
+
+	if (!scu_base) {
+		np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+		if (np) {
+			scu_base = of_iomap(np, 0);
+			of_node_put(np);
+		} else {
+			scu_base = ioremap(scu_a9_get_base(), SZ_4K);
+		}
+	}
+	scu_enable(scu_base);
+}
+
+static void __iomem *cpu_boot_reg_base(void)
+{
+	if (soc_is_exynos4210() && exynos_rev() == EXYNOS4210_REV_1_1)
+		return pmu_base_addr + 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 IOMEM_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;
+}
+
+/*
+ * Set wake up by local power mode and execute software reset for given core.
+ *
+ * Currently this is needed only when booting secondary CPU on Exynos3250.
+ */
+void exynos_core_restart(u32 core_id)
+{
+	unsigned int timeout = 16;
+	u32 val;
+
+	if (!of_machine_is_compatible("samsung,exynos3250"))
+		return;
+
+	while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
+		timeout--;
+		udelay(10);
+	}
+	if (timeout == 0) {
+		pr_err("cpu core %u restart failed\n", core_id);
+		return;
+	}
+	udelay(10);
+
+	val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
+	val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
+	pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
+
+	pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
+}
+
+/*
+ * XXX CARGO CULTED CODE - DO NOT COPY XXX
+ *
+ * Write exynos_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 exynos_write_pen_release(int val)
+{
+	exynos_pen_release = val;
+	smp_wmb();
+	sync_cache_w(&exynos_pen_release);
+}
+
+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
+	 */
+	exynos_write_pen_release(-1);
+
+	/*
+	 * Synchronise with the boot thread.
+	 */
+	spin_lock(&boot_lock);
+	spin_unlock(&boot_lock);
+}
+
+int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
+{
+	int ret;
+
+	/*
+	 * 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;
+		}
+		writel_relaxed(boot_addr, boot_reg);
+		ret = 0;
+	}
+fail:
+	return ret;
+}
+
+int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
+{
+	int ret;
+
+	/*
+	 * Try to get boot address using firmware first
+	 * and fall back to boot register if it fails.
+	 */
+	ret = call_firmware_op(get_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;
+		}
+		*boot_addr = readl_relaxed(boot_reg);
+		ret = 0;
+	}
+fail:
+	return ret;
+}
+
+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 exynos_pen_release.
+	 *
+	 * Note that "exynos_pen_release" is the hardware CPU core ID, whereas
+	 * "cpu" is Linux's internal ID.
+	 */
+	exynos_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;
+			timeout--;
+			mdelay(1);
+		}
+
+		if (timeout == 0) {
+			printk(KERN_ERR "cpu1 power enable failed");
+			spin_unlock(&boot_lock);
+			return -ETIMEDOUT;
+		}
+	}
+
+	exynos_core_restart(core_id);
+
+	/*
+	 * 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 = __pa_symbol(exynos4_secondary_startup);
+
+		ret = exynos_set_boot_addr(core_id, boot_addr);
+		if (ret)
+			goto fail;
+
+		call_firmware_op(cpu_boot, core_id);
+
+		if (soc_is_exynos3250())
+			dsb_sev();
+		else
+			arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+		if (exynos_pen_release == -1)
+			break;
+
+		udelay(10);
+	}
+
+	if (exynos_pen_release != -1)
+		ret = -ETIMEDOUT;
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+fail:
+	spin_unlock(&boot_lock);
+
+	return exynos_pen_release != -1 ? ret : 0;
+}
+
+static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
+{
+	exynos_sysram_init();
+
+	exynos_set_delayed_reset_assertion(true);
+
+	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
+		exynos_scu_enable();
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+static void exynos_cpu_die(unsigned int cpu)
+{
+	int spurious = 0;
+	u32 mpidr = cpu_logical_map(cpu);
+	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+	v7_exit_coherency_flush(louis);
+
+	platform_do_lowpower(cpu, &spurious);
+
+	/*
+	 * bring this CPU back into the world of cache
+	 * coherency, and then restore interrupts
+	 */
+	cpu_leave_lowpower(core_id);
+
+	if (spurious)
+		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+const struct smp_operations exynos_smp_ops __initconst = {
+	.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
+};