ARM: zx: enable SMP and hotplug for zx296702

Bring up the secondary core. Enable hotplug with supporting
powering off secondary core.
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-zx/Makefile

 obj-$(CONFIG_SOC_ZX296702) += zx296702.o
+obj-$(CONFIG_SMP) += headsmp.o platsmp.o

arch/arm/mach-zx/core.h

+/*
+ * Copyright 2014 Linaro Ltd.
+ * Copyright (C) 2014 ZTE Corporation.
+ *
+ * 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.
+ */
+
+#ifndef __MACH_ZX_CORE_H
+#define __MACH_ZX_CORE_H
+
+extern void zx_resume_jump(void);
+extern size_t zx_suspend_iram_sz;
+extern unsigned long zx_secondary_startup_pa;
+
+void zx_secondary_startup(void);
+
+#endif /* __MACH_ZX_CORE_H */

arch/arm/mach-zx/headsmp.S

+/*
+ * Copyright 2014 Linaro Ltd.
+ * Copyright (C) 2014 ZTE Corporation.
+ *
+ * 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/linkage.h>
+
+	.align 3
+
+/* It runs from physical address */
+ENTRY(zx_resume_jump)
+	adr	r1, zx_secondary_startup_pa
+	ldr	r0, [r1]
+	bx	r0
+ENDPROC(zx_resume_jump)
+
+ENTRY(zx_secondary_startup_pa)
+	.word	zx_secondary_startup_pa
+
+ENTRY(zx_suspend_iram_sz)
+        .word	. - zx_resume_jump
+ENDPROC(zx_secondary_startup_pa)
+
+
+ENTRY(zx_secondary_startup)
+	bl	v7_invalidate_l1
+	b	secondary_startup
+ENDPROC(zx_secondary_startup)

arch/arm/mach-zx/platsmp.c

+/*
+ * Copyright 2014 Linaro Ltd.
+ * Copyright (C) 2014 ZTE Corporation.
+ *
+ * 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/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/fncpy.h>
+#include <asm/proc-fns.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_plat.h>
+
+#include "core.h"
+
+#define AON_SYS_CTRL_RESERVED1		0xa8
+
+#define BUS_MATRIX_REMAP_CONFIG		0x00
+
+#define PCU_CPU0_CTRL			0x00
+#define PCU_CPU1_CTRL			0x04
+#define PCU_CPU1_ST			0x0c
+#define PCU_GLOBAL_CTRL			0x14
+#define PCU_EXPEND_CONTROL		0x34
+
+#define ZX_IRAM_BASE			0x00200000
+
+static void __iomem *pcu_base;
+static void __iomem *matrix_base;
+static void __iomem *scu_base;
+
+void __init zx_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *np;
+	unsigned long base = 0;
+	void __iomem *aonsysctrl_base;
+	void __iomem *sys_iram;
+
+	base = scu_a9_get_base();
+	scu_base = ioremap(base, SZ_256);
+	if (!scu_base) {
+		pr_err("%s: failed to map scu\n", __func__);
+		return;
+	}
+
+	scu_enable(scu_base);
+
+	np = of_find_compatible_node(NULL, NULL, "zte,sysctrl");
+	if (!np) {
+		pr_err("%s: failed to find sysctrl node\n", __func__);
+		return;
+	}
+
+	aonsysctrl_base = of_iomap(np, 0);
+	if (!aonsysctrl_base) {
+		pr_err("%s: failed to map aonsysctrl\n", __func__);
+		of_node_put(np);
+		return;
+	}
+
+	/*
+	 * Write the address of secondary startup into the
+	 * system-wide flags register. The BootMonitor waits
+	 * until it receives a soft interrupt, and then the
+	 * secondary CPU branches to this address.
+	 */
+	__raw_writel(virt_to_phys(zx_secondary_startup),
+		     aonsysctrl_base + AON_SYS_CTRL_RESERVED1);
+
+	iounmap(aonsysctrl_base);
+	of_node_put(np);
+
+	np = of_find_compatible_node(NULL, NULL, "zte,zx296702-pcu");
+	pcu_base = of_iomap(np, 0);
+	of_node_put(np);
+	WARN_ON(!pcu_base);
+
+	np = of_find_compatible_node(NULL, NULL, "zte,zx-bus-matrix");
+	matrix_base = of_iomap(np, 0);
+	of_node_put(np);
+	WARN_ON(!matrix_base);
+
+	/* Map the first 4 KB IRAM for suspend usage */
+	sys_iram = __arm_ioremap_exec(ZX_IRAM_BASE, PAGE_SIZE, false);
+	zx_secondary_startup_pa = virt_to_phys(zx_secondary_startup);
+	fncpy(sys_iram, &zx_resume_jump, zx_suspend_iram_sz);
+}
+
+static int zx_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	static bool first_boot = true;
+
+	if (first_boot) {
+		arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+		first_boot = false;
+		return 0;
+	}
+
+	/* Swap the base address mapping between IRAM and IROM */
+	writel_relaxed(0x1, matrix_base + BUS_MATRIX_REMAP_CONFIG);
+
+	/* Power on CPU1 */
+	writel_relaxed(0x0, pcu_base + PCU_CPU1_CTRL);
+
+	/* Wait for power on ack */
+	while (readl_relaxed(pcu_base + PCU_CPU1_ST) & 0x4)
+		cpu_relax();
+
+	/* Swap back the mapping of IRAM and IROM */
+	writel_relaxed(0x0, matrix_base + BUS_MATRIX_REMAP_CONFIG);
+
+	return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static inline void cpu_enter_lowpower(void)
+{
+	unsigned int v;
+
+	asm volatile(
+		"mcr	p15, 0, %1, c7, c5, 0\n"
+	"	mcr	p15, 0, %1, c7, c10, 4\n"
+	/*
+	 * Turn off coherency
+	 */
+	"	mrc	p15, 0, %0, c1, c0, 1\n"
+	"	bic	%0, %0, %3\n"
+	"	mcr	p15, 0, %0, c1, c0, 1\n"
+	"	mrc	p15, 0, %0, c1, c0, 0\n"
+	"	bic	%0, %0, %2\n"
+	"	mcr	p15, 0, %0, c1, c0, 0\n"
+	  : "=&r" (v)
+	  : "r" (0), "Ir" (CR_C), "Ir" (0x40)
+	  : "cc");
+}
+
+static int zx_cpu_kill(unsigned int cpu)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(2000);
+
+	writel_relaxed(0x2, pcu_base + PCU_CPU1_CTRL);
+
+	while ((readl_relaxed(pcu_base + PCU_CPU1_ST) & 0x3) != 0x0) {
+		if (time_after(jiffies, timeout)) {
+			pr_err("*** cpu1 poweroff timeout\n");
+			break;
+		}
+	}
+	return 1;
+}
+
+static void zx_cpu_die(unsigned int cpu)
+{
+	scu_power_mode(scu_base, SCU_PM_POWEROFF);
+	cpu_enter_lowpower();
+
+	while (1)
+		cpu_do_idle();
+}
+#endif
+
+static void zx_secondary_init(unsigned int cpu)
+{
+	scu_power_mode(scu_base, SCU_PM_NORMAL);
+}
+
+struct smp_operations zx_smp_ops __initdata = {
+	.smp_prepare_cpus	= zx_smp_prepare_cpus,
+	.smp_secondary_init	= zx_secondary_init,
+	.smp_boot_secondary	= zx_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_kill		= zx_cpu_kill,
+	.cpu_die		= zx_cpu_die,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(zx_smp, "zte,zx296702-smp", &zx_smp_ops);