[PATCH 01/03] ARM: mach-shmobile: SMP base support
Magnus Damm
magnus.damm at gmail.com
Tue Dec 14 02:56:55 EST 2010
From: Magnus Damm <damm at opensource.se>
Add SMP base support for R-Mobile / SH-Mobile processors.
This patch contains all base code to support CONFIG_SMP
regardless of ARCH_SHMOBILE processor type. Both local timer
and CPU hotplug are supported, but no processor specific
code is included.
At this point only the default behavior is in place, so
a single core will always be used even though CONFIG_SMP
is enabled on multicore systems.
The SMP Kconfig entry for arch/arm/Kconfig is excluded from
this patch to simplify merging.
Signed-off-by: Magnus Damm <damm at opensource.se>
---
Future patches may be required to sync up the framework
bits with current/upcoming changes in RMKs git repository.
arch/arm/mach-shmobile/Makefile | 6 +
arch/arm/mach-shmobile/headsmp.S | 26 +++++
arch/arm/mach-shmobile/hotplug.c | 41 ++++++++
arch/arm/mach-shmobile/include/mach/common.h | 1
arch/arm/mach-shmobile/include/mach/entry-macro-intc.S | 6 +
arch/arm/mach-shmobile/include/mach/smp.h | 16 +++
arch/arm/mach-shmobile/localtimer.c | 25 +++++
arch/arm/mach-shmobile/platsmp.c | 73 ++++++++++++++++
8 files changed, 194 insertions(+)
--- 0006/arch/arm/mach-shmobile/Makefile
+++ work/arch/arm/mach-shmobile/Makefile 2010-12-14 13:50:20.000000000 +0900
@@ -11,6 +11,11 @@ obj-$(CONFIG_ARCH_SH7377) += setup-sh737
obj-$(CONFIG_ARCH_SH7372) += setup-sh7372.o clock-sh7372.o intc-sh7372.o
obj-$(CONFIG_ARCH_SH73A0) += setup-sh73a0.o clock-sh73a0.o
+# SMP objects
+smp-y := platsmp.o headsmp.o
+smp-$(CONFIG_HOTPLUG_CPU) += hotplug.o
+smp-$(CONFIG_LOCAL_TIMERS) += localtimer.o
+
# Pinmux setup
pfc-y :=
pfc-$(CONFIG_ARCH_SH7367) += pfc-sh7367.o
@@ -26,4 +31,5 @@ obj-$(CONFIG_MACH_AG5EVM) += board-ag5ev
obj-$(CONFIG_MACH_MACKEREL) += board-mackerel.o
# Framework support
+obj-$(CONFIG_SMP) += $(smp-y)
obj-$(CONFIG_GENERIC_GPIO) += $(pfc-y)
--- /dev/null
+++ work/arch/arm/mach-shmobile/headsmp.S 2010-12-14 13:50:21.000000000 +0900
@@ -0,0 +1,26 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile
+ *
+ * Copyright (C) 2010 Magnus Damm
+ * Copyright (C) 2010 Takashi Yoshii
+ *
+ * Based on vexpress, Copyright (c) 2003 ARM Limited, 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/linkage.h>
+#include <linux/init.h>
+
+ __INIT
+
+/*
+ * Reset vector for secondary CPUs.
+ * This will be mapped at address 0 by SBAR register.
+ * We need _long_ jump to the physical address.
+ */
+ .align 12
+ENTRY(shmobile_secondary_vector)
+ ldr pc, 1f
+1: .long secondary_startup - CONFIG_PAGE_OFFSET + CONFIG_MEMORY_START
--- /dev/null
+++ work/arch/arm/mach-shmobile/hotplug.c 2010-12-14 13:50:21.000000000 +0900
@@ -0,0 +1,41 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile
+ *
+ * Copyright (C) 2010 Magnus Damm
+ *
+ * Based on realview, 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/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+int platform_cpu_kill(unsigned int cpu)
+{
+ return 1;
+}
+
+void platform_cpu_die(unsigned int cpu)
+{
+ while (1) {
+ /*
+ * here's the WFI
+ */
+ asm(".word 0xe320f003\n"
+ :
+ :
+ : "memory", "cc");
+ }
+}
+
+int platform_cpu_disable(unsigned int cpu)
+{
+ /*
+ * we don't allow CPU 0 to be shutdown (it is still too special
+ * e.g. clock tick interrupts)
+ */
+ return cpu == 0 ? -EPERM : 0;
+}
--- 0001/arch/arm/mach-shmobile/include/mach/common.h
+++ work/arch/arm/mach-shmobile/include/mach/common.h 2010-12-14 13:50:20.000000000 +0900
@@ -3,6 +3,7 @@
extern struct sys_timer shmobile_timer;
extern void shmobile_setup_console(void);
+extern void shmobile_secondary_vector(void);
struct clk;
extern int clk_init(void);
--- 0001/arch/arm/mach-shmobile/include/mach/entry-macro-intc.S
+++ work/arch/arm/mach-shmobile/include/mach/entry-macro-intc.S 2010-12-14 13:50:20.000000000 +0900
@@ -17,6 +17,12 @@
#include <mach/hardware.h>
#include <mach/irqs.h>
+ .macro test_for_ipi, irqnr, irqstat, base, tmp
+ .endm
+
+ .macro test_for_ltirq, irqnr, irqstat, base, tmp
+ .endm
+
.macro disable_fiq
.endm
--- /dev/null
+++ work/arch/arm/mach-shmobile/include/mach/smp.h 2010-12-14 13:50:21.000000000 +0900
@@ -0,0 +1,16 @@
+#ifndef __MACH_SMP_H
+#define __MACH_SMP_H
+
+#include <asm/hardware/gic.h>
+#include <asm/smp_mpidr.h>
+
+/*
+ * We use IRQ1 as the IPI
+ */
+static inline void smp_cross_call(const struct cpumask *mask)
+{
+#if defined(CONFIG_ARM_GIC)
+ gic_raise_softirq(mask, 1);
+#endif
+}
+#endif
--- /dev/null
+++ work/arch/arm/mach-shmobile/localtimer.c 2010-12-14 14:31:51.000000000 +0900
@@ -0,0 +1,25 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile - local timer portion
+ *
+ * Copyright (C) 2010 Magnus Damm
+ *
+ * Based on vexpress, 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/smp.h>
+#include <linux/clockchips.h>
+#include <asm/smp_twd.h>
+#include <asm/localtimer.h>
+
+/*
+ * Setup the local clock events for a CPU.
+ */
+void __cpuinit local_timer_setup(struct clock_event_device *evt)
+{
+ evt->irq = 29;
+ twd_timer_setup(evt);
+}
--- /dev/null
+++ work/arch/arm/mach-shmobile/platsmp.c 2010-12-14 14:32:27.000000000 +0900
@@ -0,0 +1,73 @@
+/*
+ * SMP support for R-Mobile / SH-Mobile
+ *
+ * Copyright (C) 2010 Magnus Damm
+ *
+ * Based on vexpress, 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/device.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <asm/localtimer.h>
+
+static unsigned int __init shmobile_smp_get_core_count(void)
+{
+ return 1;
+}
+
+static void __init shmobile_smp_prepare_cpus(void)
+{
+ /* do nothing for now */
+}
+
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+ trace_hardirqs_off();
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ return -ENOSYS;
+}
+
+void __init smp_init_cpus(void)
+{
+ unsigned int ncores = shmobile_smp_get_core_count();
+ unsigned int i;
+
+ for (i = 0; i < ncores; i++)
+ set_cpu_possible(i, true);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int ncores = shmobile_smp_get_core_count();
+ unsigned int cpu = smp_processor_id();
+ int i;
+
+ smp_store_cpu_info(cpu);
+
+ if (max_cpus > ncores)
+ max_cpus = ncores;
+
+ for (i = 0; i < max_cpus; i++)
+ set_cpu_present(i, true);
+
+ if (max_cpus > 1) {
+ shmobile_smp_prepare_cpus();
+
+ /*
+ * Enable the local timer or broadcast device for the
+ * boot CPU, but only if we have more than one CPU.
+ */
+ percpu_timer_setup();
+ }
+}
More information about the linux-arm-kernel
mailing list