aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/kernel/smp.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh/kernel/smp.c
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sh/kernel/smp.c')
-rw-r--r--arch/sh/kernel/smp.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
new file mode 100644
index 000000000000..56a39d69e080
--- /dev/null
+++ b/arch/sh/kernel/smp.c
@@ -0,0 +1,199 @@
+/*
+ * arch/sh/kernel/smp.c
+ *
+ * SMP support for the SuperH processors.
+ *
+ * Copyright (C) 2002, 2003 Paul Mundt
+ *
+ * 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.
+ */
+#include <linux/config.h>
+#include <linux/cache.h>
+#include <linux/cpumask.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/threads.h>
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/sched.h>
+
+#include <asm/atomic.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/mmu_context.h>
+#include <asm/smp.h>
+
+/*
+ * This was written with the Sega Saturn (SMP SH-2 7604) in mind,
+ * but is designed to be usable regardless if there's an MMU
+ * present or not.
+ */
+struct sh_cpuinfo cpu_data[NR_CPUS];
+
+extern void per_cpu_trap_init(void);
+
+cpumask_t cpu_possible_map;
+cpumask_t cpu_online_map;
+static atomic_t cpus_booted = ATOMIC_INIT(0);
+
+/* These are defined by the board-specific code. */
+
+/*
+ * Cause the function described by call_data to be executed on the passed
+ * cpu. When the function has finished, increment the finished field of
+ * call_data.
+ */
+void __smp_send_ipi(unsigned int cpu, unsigned int action);
+
+/*
+ * Find the number of available processors
+ */
+unsigned int __smp_probe_cpus(void);
+
+/*
+ * Start a particular processor
+ */
+void __smp_slave_init(unsigned int cpu);
+
+/*
+ * Run specified function on a particular processor.
+ */
+void __smp_call_function(unsigned int cpu);
+
+static inline void __init smp_store_cpu_info(unsigned int cpu)
+{
+ cpu_data[cpu].loops_per_jiffy = loops_per_jiffy;
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int cpu = smp_processor_id();
+ int i;
+
+ atomic_set(&cpus_booted, 1);
+ smp_store_cpu_info(cpu);
+
+ for (i = 0; i < __smp_probe_cpus(); i++)
+ cpu_set(i, cpu_possible_map);
+}
+
+void __devinit smp_prepare_boot_cpu(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ cpu_set(cpu, cpu_online_map);
+ cpu_set(cpu, cpu_possible_map);
+}
+
+int __cpu_up(unsigned int cpu)
+{
+ struct task_struct *tsk;
+
+ tsk = fork_idle(cpu);
+
+ if (IS_ERR(tsk))
+ panic("Failed forking idle task for cpu %d\n", cpu);
+
+ tsk->thread_info->cpu = cpu;
+
+ cpu_set(cpu, cpu_online_map);
+
+ return 0;
+}
+
+int start_secondary(void *unused)
+{
+ unsigned int cpu = smp_processor_id();
+
+ atomic_inc(&init_mm.mm_count);
+ current->active_mm = &init_mm;
+
+ smp_store_cpu_info(cpu);
+
+ __smp_slave_init(cpu);
+ per_cpu_trap_init();
+
+ atomic_inc(&cpus_booted);
+
+ cpu_idle();
+ return 0;
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+ smp_mb();
+}
+
+void smp_send_reschedule(int cpu)
+{
+ __smp_send_ipi(cpu, SMP_MSG_RESCHEDULE);
+}
+
+static void stop_this_cpu(void *unused)
+{
+ cpu_clear(smp_processor_id(), cpu_online_map);
+ local_irq_disable();
+
+ for (;;)
+ cpu_relax();
+}
+
+void smp_send_stop(void)
+{
+ smp_call_function(stop_this_cpu, 0, 1, 0);
+}
+
+
+struct smp_fn_call_struct smp_fn_call = {
+ .lock = SPIN_LOCK_UNLOCKED,
+ .finished = ATOMIC_INIT(0),
+};
+
+/*
+ * The caller of this wants the passed function to run on every cpu. If wait
+ * is set, wait until all cpus have finished the function before returning.
+ * The lock is here to protect the call structure.
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
+{
+ unsigned int nr_cpus = atomic_read(&cpus_booted);
+ int i;
+
+ if (nr_cpus < 2)
+ return 0;
+
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ spin_lock(&smp_fn_call.lock);
+
+ atomic_set(&smp_fn_call.finished, 0);
+ smp_fn_call.fn = func;
+ smp_fn_call.data = info;
+
+ for (i = 0; i < nr_cpus; i++)
+ if (i != smp_processor_id())
+ __smp_call_function(i);
+
+ if (wait)
+ while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
+
+ spin_unlock(&smp_fn_call.lock);
+
+ return 0;
+}
+
+/* Not really SMP stuff ... */
+int setup_profiling_timer(unsigned int multiplier)
+{
+ return 0;
+}
+