1 files changed, 96 insertions, 0 deletions
diff --git a/arch/arm/mach-oxnas/platsmp.c b/arch/arm/mach-oxnas/platsmp.c
new file mode 100644
index 000000000..f0a50b9e6
--- /dev/null
+++ b/arch/arm/mach-oxnas/platsmp.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ */
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+extern void ox820_secondary_startup(void);
+
+static void __iomem *cpu_ctrl;
+static void __iomem *gic_cpu_ctrl;
+
+#define HOLDINGPEN_CPU_OFFSET		0xc8
+#define HOLDINGPEN_LOCATION_OFFSET	0xc4
+
+#define GIC_NCPU_OFFSET(cpu)		(0x100 + (cpu)*0x100)
+#define GIC_CPU_CTRL			0x00
+#define GIC_CPU_CTRL_ENABLE		1
+
+static int __init ox820_boot_secondary(unsigned int cpu,
+		struct task_struct *idle)
+{
+	/*
+	 * 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.
+	 */
+	writel(virt_to_phys(ox820_secondary_startup),
+			cpu_ctrl + HOLDINGPEN_LOCATION_OFFSET);
+
+	writel(cpu, cpu_ctrl + HOLDINGPEN_CPU_OFFSET);
+
+	/*
+	 * Enable GIC cpu interface in CPU Interface Control Register
+	 */
+	writel(GIC_CPU_CTRL_ENABLE,
+		gic_cpu_ctrl + GIC_NCPU_OFFSET(cpu) + GIC_CPU_CTRL);
+
+	/*
+	 * 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.
+	 */
+	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+	return 0;
+}
+
+static void __init ox820_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *np;
+	void __iomem *scu_base;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-scu");
+	scu_base = of_iomap(np, 0);
+	of_node_put(np);
+	if (!scu_base)
+		return;
+
+	/* Remap CPU Interrupt Interface Registers */
+	np = of_find_compatible_node(NULL, NULL, "arm,arm11mp-gic");
+	gic_cpu_ctrl = of_iomap(np, 1);
+	of_node_put(np);
+	if (!gic_cpu_ctrl)
+		goto unmap_scu;
+
+	np = of_find_compatible_node(NULL, NULL, "oxsemi,ox820-sys-ctrl");
+	cpu_ctrl = of_iomap(np, 0);
+	of_node_put(np);
+	if (!cpu_ctrl)
+		goto unmap_scu;
+
+	scu_enable(scu_base);
+	flush_cache_all();
+
+unmap_scu:
+	iounmap(scu_base);
+}
+
+static const struct smp_operations ox820_smp_ops __initconst = {
+	.smp_prepare_cpus	= ox820_smp_prepare_cpus,
+	.smp_boot_secondary	= ox820_boot_secondary,
+};
+
+CPU_METHOD_OF_DECLARE(ox820_smp, "oxsemi,ox820-smp", &ox820_smp_ops);