File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c
new file mode 100644
index 0000000..7f27001
--- /dev/null
+++ b/arch/arm/mach-imx/platsmp.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+#include <asm/smp_scu.h>
+#include <asm/mach/map.h>
+
+#include "common.h"
+#include "hardware.h"
+
+u32 g_diag_reg;
+static void __iomem *scu_base;
+
+static struct map_desc scu_io_desc __initdata = {
+	/* .virtual and .pfn are run-time assigned */
+	.length		= SZ_4K,
+	.type		= MT_DEVICE,
+};
+
+void __init imx_scu_map_io(void)
+{
+	unsigned long base;
+
+	/* Get SCU base */
+	asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (base));
+
+	scu_io_desc.virtual = IMX_IO_P2V(base);
+	scu_io_desc.pfn = __phys_to_pfn(base);
+	iotable_init(&scu_io_desc, 1);
+
+	scu_base = IMX_IO_ADDRESS(base);
+}
+
+static int imx_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	imx_set_cpu_jump(cpu, v7_secondary_startup);
+	imx_enable_cpu(cpu, true);
+	return 0;
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+static void __init imx_smp_init_cpus(void)
+{
+	int i, ncores;
+
+	ncores = scu_get_core_count(scu_base);
+
+	for (i = ncores; i < NR_CPUS; i++)
+		set_cpu_possible(i, false);
+}
+
+void imx_smp_prepare(void)
+{
+	scu_enable(scu_base);
+}
+
+static void __init imx_smp_prepare_cpus(unsigned int max_cpus)
+{
+	imx_smp_prepare();
+
+	/*
+	 * The diagnostic register holds the errata bits.  Mostly bootloader
+	 * does not bring up secondary cores, so that when errata bits are set
+	 * in bootloader, they are set only for boot cpu.  But on a SMP
+	 * configuration, it should be equally done on every single core.
+	 * Read the register from boot cpu here, and will replicate it into
+	 * secondary cores when booting them.
+	 */
+	asm("mrc p15, 0, %0, c15, c0, 1" : "=r" (g_diag_reg) : : "cc");
+	sync_cache_w(&g_diag_reg);
+}
+
+struct smp_operations  imx_smp_ops __initdata = {
+	.smp_init_cpus		= imx_smp_init_cpus,
+	.smp_prepare_cpus	= imx_smp_prepare_cpus,
+	.smp_boot_secondary	= imx_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= imx_cpu_die,
+	.cpu_kill		= imx_cpu_kill,
+#endif
+};
+
+#define DCFG_CCSR_SCRATCHRW1	0x200
+
+static int ls1021a_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+	return 0;
+}
+
+static void __init ls1021a_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *np;
+	void __iomem *dcfg_base;
+	unsigned long paddr;
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,ls1021a-dcfg");
+	dcfg_base = of_iomap(np, 0);
+	BUG_ON(!dcfg_base);
+
+	paddr = virt_to_phys(secondary_startup);
+	writel_relaxed(cpu_to_be32(paddr), dcfg_base + DCFG_CCSR_SCRATCHRW1);
+
+	iounmap(dcfg_base);
+}
+
+struct smp_operations  ls1021a_smp_ops __initdata = {
+	.smp_prepare_cpus	= ls1021a_smp_prepare_cpus,
+	.smp_boot_secondary	= ls1021a_boot_secondary,
+};