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authorLinus Walleij <linus.walleij@linaro.org>2015-10-09 13:38:57 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-12-15 09:42:52 +0100
commit5420b4b156179ec634d9e42279b6898b85852960 (patch)
tree43ebde876ef96fa3881e159d24b8e3f76ea12717 /arch/arm/mach-realview
parentca5b21fa6ec61cdf8906265141a9f15169d2808b (diff)
downloadlinux-next-5420b4b156179ec634d9e42279b6898b85852960.tar.gz
ARM: realview: add an DT SMP boot method
This adds an SMP boot method for the ARM RealView reference designs. We also select HAVE_SMP by default and make it use SMP_ON_UP so we only need to support one single kernel across the RealView reference designs when using DT. The RealViews need to have the SCU (Snoop Control Unit) activated on boot, and this is now done by looking up its address from the device tree and initializing it and counting the available cores. The RealViews boot by using a magic address register in the system controller (SYS_FLAGS) to store the boot address, the ROM will then read this register to the PC when the CPUs are taken out of WFI. This code uses a handle to the syscon regmap to access this register. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'arch/arm/mach-realview')
-rw-r--r--arch/arm/mach-realview/Kconfig2
-rw-r--r--arch/arm/mach-realview/Makefile2
-rw-r--r--arch/arm/mach-realview/platsmp-dt.c91
3 files changed, 94 insertions, 1 deletions
diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index edbc925e42c2..7316fff0f3ba 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -5,11 +5,13 @@ config REALVIEW_DT
bool "Support RealView(R) Device Tree based boot"
select ARM_GIC
select CLK_SP810
+ select HAVE_SMP
select ICST
select MFD_SYSCON
select POWER_RESET
select POWER_RESET_VERSATILE
select POWER_SUPPLY
+ select SMP_ON_UP
select SOC_REALVIEW
select USE_OF
help
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index e07fdf7ae8a7..a46fa694cf07 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -3,7 +3,7 @@
#
obj-y := core.o
-obj-$(CONFIG_REALVIEW_DT) += realview-dt.o
+obj-$(CONFIG_REALVIEW_DT) += realview-dt.o platsmp-dt.o
obj-$(CONFIG_MACH_REALVIEW_EB) += realview_eb.o
obj-$(CONFIG_MACH_REALVIEW_PB11MP) += realview_pb11mp.o
obj-$(CONFIG_MACH_REALVIEW_PB1176) += realview_pb1176.o
diff --git a/arch/arm/mach-realview/platsmp-dt.c b/arch/arm/mach-realview/platsmp-dt.c
new file mode 100644
index 000000000000..65585392655b
--- /dev/null
+++ b/arch/arm/mach-realview/platsmp-dt.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2015 Linus Walleij
+ *
+ * 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/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#include <plat/platsmp.h>
+
+#include "core.h"
+
+#define REALVIEW_SYS_FLAGSSET_OFFSET 0x30
+
+static const struct of_device_id realview_scu_match[] = {
+ { .compatible = "arm,arm11mp-scu", },
+ { .compatible = "arm,cortex-a9-scu", },
+ { .compatible = "arm,cortex-a5-scu", },
+ { }
+};
+
+static const struct of_device_id realview_syscon_match[] = {
+ { .compatible = "arm,core-module-integrator", },
+ { .compatible = "arm,realview-eb-syscon", },
+ { .compatible = "arm,realview-pb11mp-syscon", },
+ { .compatible = "arm,realview-pbx-syscon", },
+ { },
+};
+
+static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *np;
+ void __iomem *scu_base;
+ struct regmap *map;
+ unsigned int ncores;
+ int i;
+
+ np = of_find_matching_node(NULL, realview_scu_match);
+ if (!np) {
+ pr_err("PLATSMP: No SCU base address\n");
+ return;
+ }
+ scu_base = of_iomap(np, 0);
+ of_node_put(np);
+ if (!scu_base) {
+ pr_err("PLATSMP: No SCU remap\n");
+ return;
+ }
+
+ scu_enable(scu_base);
+ ncores = scu_get_core_count(scu_base);
+ pr_info("SCU: %d cores detected\n", ncores);
+ for (i = 0; i < ncores; i++)
+ set_cpu_possible(i, true);
+ iounmap(scu_base);
+
+ /* The syscon contains the magic SMP start address registers */
+ np = of_find_matching_node(NULL, realview_syscon_match);
+ if (!np) {
+ pr_err("PLATSMP: No syscon match\n");
+ return;
+ }
+ map = syscon_node_to_regmap(np);
+ if (IS_ERR(map)) {
+ pr_err("PLATSMP: No syscon regmap\n");
+ return;
+ }
+ /* Put the boot address in this magic register */
+ regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
+ virt_to_phys(versatile_secondary_startup));
+}
+
+struct smp_operations realview_dt_smp_ops __initdata = {
+ .smp_prepare_cpus = realview_smp_prepare_cpus,
+ .smp_secondary_init = versatile_secondary_init,
+ .smp_boot_secondary = versatile_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = realview_cpu_die,
+#endif
+};
+CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);