These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 209 insertions, 0 deletions

diff --git a/kernel/arch/arm/mach-uniphier/platsmp.c b/kernel/arch/arm/mach-uniphier/platsmp.c
new file mode 100644
index 000000000..f05776646
--- /dev/null
+++ b/kernel/arch/arm/mach-uniphier/platsmp.c
@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt)		"uniphier: " fmt
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/sizes.h>
+#include <asm/cacheflush.h>
+#include <asm/hardware/cache-uniphier.h>
+#include <asm/pgtable.h>
+#include <asm/smp.h>
+#include <asm/smp_scu.h>
+
+/*
+ * The secondary CPUs check this register from the boot ROM for the jump
+ * destination.  After that, it can be reused as a scratch register.
+ */
+#define UNIPHIER_SBC_ROM_BOOT_RSV2	0x1208
+
+static void __iomem *uniphier_smp_rom_boot_rsv2;
+static unsigned int uniphier_smp_max_cpus;
+
+extern char uniphier_smp_trampoline;
+extern char uniphier_smp_trampoline_jump;
+extern char uniphier_smp_trampoline_poll_addr;
+extern char uniphier_smp_trampoline_end;
+
+/*
+ * Copy trampoline code to the tail of the 1st section of the page table used
+ * in the boot ROM.  This area is directly accessible by the secondary CPUs
+ * for all the UniPhier SoCs.
+ */
+static const phys_addr_t uniphier_smp_trampoline_dest_end = SECTION_SIZE;
+static phys_addr_t uniphier_smp_trampoline_dest;
+
+static int __init uniphier_smp_copy_trampoline(phys_addr_t poll_addr)
+{
+	size_t trmp_size;
+	static void __iomem *trmp_base;
+
+	if (!uniphier_cache_l2_is_enabled()) {
+		pr_warn("outer cache is needed for SMP, but not enabled\n");
+		return -ENODEV;
+	}
+
+	uniphier_cache_l2_set_locked_ways(1);
+
+	outer_flush_all();
+
+	trmp_size = &uniphier_smp_trampoline_end - &uniphier_smp_trampoline;
+	uniphier_smp_trampoline_dest = uniphier_smp_trampoline_dest_end -
+								trmp_size;
+
+	uniphier_cache_l2_touch_range(uniphier_smp_trampoline_dest,
+				      uniphier_smp_trampoline_dest_end);
+
+	trmp_base = ioremap_cache(uniphier_smp_trampoline_dest, trmp_size);
+	if (!trmp_base) {
+		pr_err("failed to map trampoline destination area\n");
+		return -ENOMEM;
+	}
+
+	memcpy(trmp_base, &uniphier_smp_trampoline, trmp_size);
+
+	writel(virt_to_phys(secondary_startup),
+	       trmp_base + (&uniphier_smp_trampoline_jump -
+			    &uniphier_smp_trampoline));
+
+	writel(poll_addr, trmp_base + (&uniphier_smp_trampoline_poll_addr -
+				       &uniphier_smp_trampoline));
+
+	flush_cache_all();	/* flush out trampoline code to outer cache */
+
+	iounmap(trmp_base);
+
+	return 0;
+}
+
+static int __init uniphier_smp_prepare_trampoline(unsigned int max_cpus)
+{
+	struct device_node *np;
+	struct resource res;
+	phys_addr_t rom_rsv2_phys;
+	int ret;
+
+	np = of_find_compatible_node(NULL, NULL,
+				"socionext,uniphier-system-bus-controller");
+	ret = of_address_to_resource(np, 1, &res);
+	if (ret) {
+		pr_err("failed to get resource of system-bus-controller\n");
+		return ret;
+	}
+
+	rom_rsv2_phys = res.start + UNIPHIER_SBC_ROM_BOOT_RSV2;
+
+	ret = uniphier_smp_copy_trampoline(rom_rsv2_phys);
+	if (ret)
+		return ret;
+
+	uniphier_smp_rom_boot_rsv2 = ioremap(rom_rsv2_phys, sizeof(SZ_4));
+	if (!uniphier_smp_rom_boot_rsv2) {
+		pr_err("failed to map ROM_BOOT_RSV2 register\n");
+		return -ENOMEM;
+	}
+
+	writel(uniphier_smp_trampoline_dest, uniphier_smp_rom_boot_rsv2);
+	asm("sev"); /* Bring up all secondary CPUs to the trampoline code */
+
+	uniphier_smp_max_cpus = max_cpus;	/* save for later use */
+
+	return 0;
+}
+
+static void __init uniphier_smp_unprepare_trampoline(void)
+{
+	iounmap(uniphier_smp_rom_boot_rsv2);
+
+	if (uniphier_smp_trampoline_dest)
+		outer_inv_range(uniphier_smp_trampoline_dest,
+				uniphier_smp_trampoline_dest_end);
+
+	uniphier_cache_l2_set_locked_ways(0);
+}
+
+static int __init uniphier_smp_enable_scu(void)
+{
+	unsigned long scu_base_phys = 0;
+	void __iomem *scu_base;
+
+	if (scu_a9_has_base())
+		scu_base_phys = scu_a9_get_base();
+
+	if (!scu_base_phys) {
+		pr_err("failed to get scu base\n");
+		return -ENODEV;
+	}
+
+	scu_base = ioremap(scu_base_phys, SZ_128);
+	if (!scu_base) {
+		pr_err("failed to map scu base\n");
+		return -ENOMEM;
+	}
+
+	scu_enable(scu_base);
+	iounmap(scu_base);
+
+	return 0;
+}
+
+static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus)
+{
+	static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 };
+	int ret;
+
+	ret = uniphier_smp_prepare_trampoline(max_cpus);
+	if (ret)
+		goto err;
+
+	ret = uniphier_smp_enable_scu();
+	if (ret)
+		goto err;
+
+	return;
+err:
+	pr_warn("disabling SMP\n");
+	init_cpu_present(&only_cpu_0);
+	uniphier_smp_unprepare_trampoline();
+}
+
+static int __init uniphier_smp_boot_secondary(unsigned int cpu,
+					      struct task_struct *idle)
+{
+	if (WARN_ON_ONCE(!uniphier_smp_rom_boot_rsv2))
+		return -EFAULT;
+
+	writel(cpu, uniphier_smp_rom_boot_rsv2);
+	readl(uniphier_smp_rom_boot_rsv2); /* relax */
+
+	asm("sev"); /* wake up secondary CPUs sleeping in the trampoline */
+
+	if (cpu == uniphier_smp_max_cpus - 1) {
+		/* clean up resources if this is the last CPU */
+		uniphier_smp_unprepare_trampoline();
+	}
+
+	return 0;
+}
+
+static struct smp_operations uniphier_smp_ops __initdata = {
+	.smp_prepare_cpus	= uniphier_smp_prepare_cpus,
+	.smp_boot_secondary	= uniphier_smp_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(uniphier_smp, "socionext,uniphier-smp",
+		      &uniphier_smp_ops);