Fixed MTP to work with TWRP

arch/arm/mach-sti/platsmp.c

@@ -0,0 +1,116 @@
+/*
+ *  arch/arm/mach-sti/platsmp.c
+ *
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited.
+ *		http://www.st.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/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#include "smp.h"
+
+static void write_pen_release(int val)
+{
+	pen_release = val;
+	smp_wmb();
+	sync_cache_w(&pen_release);
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void sti_secondary_init(unsigned int cpu)
+{
+	trace_hardirqs_off();
+
+	/*
+	 * 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 sti_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.
+	 *
+	 * Note that "pen_release" is the hardware CPU ID, whereas
+	 * "cpu" is Linux's internal ID.
+	 */
+	write_pen_release(cpu_logical_map(cpu));
+
+	/*
+	 * Send the secondary CPU a soft interrupt, thereby causing
+	 * it to jump to the secondary entrypoint.
+	 */
+	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		smp_rmb();
+		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
+	 */
+	spin_unlock(&boot_lock);
+
+	return pen_release != -1 ? -ENOSYS : 0;
+}
+
+static void __init sti_smp_prepare_cpus(unsigned int max_cpus)
+{
+	void __iomem *scu_base = NULL;
+	struct device_node *np = of_find_compatible_node(
+					NULL, NULL, "arm,cortex-a9-scu");
+	if (np) {
+		scu_base = of_iomap(np, 0);
+		scu_enable(scu_base);
+		of_node_put(np);
+	}
+}
+
+struct smp_operations __initdata sti_smp_ops = {
+	.smp_prepare_cpus	= sti_smp_prepare_cpus,
+	.smp_secondary_init	= sti_secondary_init,
+	.smp_boot_secondary	= sti_boot_secondary,
+};