summaryrefslogtreecommitdiff
path: root/arch/arm/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/arm/kernel/smp.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.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/arm/kernel/smp.c')
-rw-r--r--arch/arm/kernel/smp.c396
1 files changed, 396 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
new file mode 100644
index 00000000000..ecc8c333240
--- /dev/null
+++ b/arch/arm/kernel/smp.c
@@ -0,0 +1,396 @@
+/*
+ * linux/arch/arm/kernel/smp.c
+ *
+ * Copyright (C) 2002 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/config.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/cache.h>
+#include <linux/profile.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/seq_file.h>
+
+#include <asm/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu.h>
+#include <asm/processor.h>
+#include <asm/tlbflush.h>
+#include <asm/ptrace.h>
+
+/*
+ * bitmask of present and online CPUs.
+ * The present bitmask indicates that the CPU is physically present.
+ * The online bitmask indicates that the CPU is up and running.
+ */
+cpumask_t cpu_present_mask;
+cpumask_t cpu_online_map;
+
+/*
+ * structures for inter-processor calls
+ * - A collection of single bit ipi messages.
+ */
+struct ipi_data {
+ spinlock_t lock;
+ unsigned long ipi_count;
+ unsigned long bits;
+};
+
+static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
+ .lock = SPIN_LOCK_UNLOCKED,
+};
+
+enum ipi_msg_type {
+ IPI_TIMER,
+ IPI_RESCHEDULE,
+ IPI_CALL_FUNC,
+ IPI_CPU_STOP,
+};
+
+struct smp_call_struct {
+ void (*func)(void *info);
+ void *info;
+ int wait;
+ cpumask_t pending;
+ cpumask_t unfinished;
+};
+
+static struct smp_call_struct * volatile smp_call_function_data;
+static DEFINE_SPINLOCK(smp_call_function_lock);
+
+int __init __cpu_up(unsigned int cpu)
+{
+ struct task_struct *idle;
+ int ret;
+
+ /*
+ * Spawn a new process manually. Grab a pointer to
+ * its task struct so we can mess with it
+ */
+ idle = fork_idle(cpu);
+ if (IS_ERR(idle)) {
+ printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
+ return PTR_ERR(idle);
+ }
+
+ /*
+ * Now bring the CPU into our world.
+ */
+ ret = boot_secondary(cpu, idle);
+ if (ret) {
+ printk(KERN_CRIT "cpu_up: processor %d failed to boot\n", cpu);
+ /*
+ * FIXME: We need to clean up the new idle thread. --rmk
+ */
+ }
+
+ return ret;
+}
+
+/*
+ * Called by both boot and secondaries to move global data into
+ * per-processor storage.
+ */
+void __init smp_store_cpu_info(unsigned int cpuid)
+{
+ struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
+
+ cpu_info->loops_per_jiffy = loops_per_jiffy;
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+ int cpu;
+ unsigned long bogosum = 0;
+
+ for_each_online_cpu(cpu)
+ bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
+
+ printk(KERN_INFO "SMP: Total of %d processors activated "
+ "(%lu.%02lu BogoMIPS).\n",
+ num_online_cpus(),
+ bogosum / (500000/HZ),
+ (bogosum / (5000/HZ)) % 100);
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ cpu_set(cpu, cpu_present_mask);
+ cpu_set(cpu, cpu_online_map);
+}
+
+static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
+{
+ unsigned long flags;
+ unsigned int cpu;
+
+ local_irq_save(flags);
+
+ for_each_cpu_mask(cpu, callmap) {
+ struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
+
+ spin_lock(&ipi->lock);
+ ipi->bits |= 1 << msg;
+ spin_unlock(&ipi->lock);
+ }
+
+ /*
+ * Call the platform specific cross-CPU call function.
+ */
+ smp_cross_call(callmap);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * You must not call this function with disabled interrupts, from a
+ * hardware interrupt handler, nor from a bottom half handler.
+ */
+int smp_call_function_on_cpu(void (*func)(void *info), void *info, int retry,
+ int wait, cpumask_t callmap)
+{
+ struct smp_call_struct data;
+ unsigned long timeout;
+ int ret = 0;
+
+ data.func = func;
+ data.info = info;
+ data.wait = wait;
+
+ cpu_clear(smp_processor_id(), callmap);
+ if (cpus_empty(callmap))
+ goto out;
+
+ data.pending = callmap;
+ if (wait)
+ data.unfinished = callmap;
+
+ /*
+ * try to get the mutex on smp_call_function_data
+ */
+ spin_lock(&smp_call_function_lock);
+ smp_call_function_data = &data;
+
+ send_ipi_message(callmap, IPI_CALL_FUNC);
+
+ timeout = jiffies + HZ;
+ while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
+ barrier();
+
+ /*
+ * did we time out?
+ */
+ if (!cpus_empty(data.pending)) {
+ /*
+ * this may be causing our panic - report it
+ */
+ printk(KERN_CRIT
+ "CPU%u: smp_call_function timeout for %p(%p)\n"
+ " callmap %lx pending %lx, %swait\n",
+ smp_processor_id(), func, info, callmap, data.pending,
+ wait ? "" : "no ");
+
+ /*
+ * TRACE
+ */
+ timeout = jiffies + (5 * HZ);
+ while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
+ barrier();
+
+ if (cpus_empty(data.pending))
+ printk(KERN_CRIT " RESOLVED\n");
+ else
+ printk(KERN_CRIT " STILL STUCK\n");
+ }
+
+ /*
+ * whatever happened, we're done with the data, so release it
+ */
+ smp_call_function_data = NULL;
+ spin_unlock(&smp_call_function_lock);
+
+ if (!cpus_empty(data.pending)) {
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ if (wait)
+ while (!cpus_empty(data.unfinished))
+ barrier();
+ out:
+
+ return 0;
+}
+
+int smp_call_function(void (*func)(void *info), void *info, int retry,
+ int wait)
+{
+ return smp_call_function_on_cpu(func, info, retry, wait,
+ cpu_online_map);
+}
+
+void show_ipi_list(struct seq_file *p)
+{
+ unsigned int cpu;
+
+ seq_puts(p, "IPI:");
+
+ for_each_online_cpu(cpu)
+ seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
+
+ seq_putc(p, '\n');
+}
+
+static void ipi_timer(struct pt_regs *regs)
+{
+ int user = user_mode(regs);
+
+ irq_enter();
+ profile_tick(CPU_PROFILING, regs);
+ update_process_times(user);
+ irq_exit();
+}
+
+/*
+ * ipi_call_function - handle IPI from smp_call_function()
+ *
+ * Note that we copy data out of the cross-call structure and then
+ * let the caller know that we're here and have done with their data
+ */
+static void ipi_call_function(unsigned int cpu)
+{
+ struct smp_call_struct *data = smp_call_function_data;
+ void (*func)(void *info) = data->func;
+ void *info = data->info;
+ int wait = data->wait;
+
+ cpu_clear(cpu, data->pending);
+
+ func(info);
+
+ if (wait)
+ cpu_clear(cpu, data->unfinished);
+}
+
+static DEFINE_SPINLOCK(stop_lock);
+
+/*
+ * ipi_cpu_stop - handle IPI from smp_send_stop()
+ */
+static void ipi_cpu_stop(unsigned int cpu)
+{
+ spin_lock(&stop_lock);
+ printk(KERN_CRIT "CPU%u: stopping\n", cpu);
+ dump_stack();
+ spin_unlock(&stop_lock);
+
+ cpu_clear(cpu, cpu_online_map);
+
+ local_fiq_disable();
+ local_irq_disable();
+
+ while (1)
+ cpu_relax();
+}
+
+/*
+ * Main handler for inter-processor interrupts
+ *
+ * For ARM, the ipimask now only identifies a single
+ * category of IPI (Bit 1 IPIs have been replaced by a
+ * different mechanism):
+ *
+ * Bit 0 - Inter-processor function call
+ */
+void do_IPI(struct pt_regs *regs)
+{
+ unsigned int cpu = smp_processor_id();
+ struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
+
+ ipi->ipi_count++;
+
+ for (;;) {
+ unsigned long msgs;
+
+ spin_lock(&ipi->lock);
+ msgs = ipi->bits;
+ ipi->bits = 0;
+ spin_unlock(&ipi->lock);
+
+ if (!msgs)
+ break;
+
+ do {
+ unsigned nextmsg;
+
+ nextmsg = msgs & -msgs;
+ msgs &= ~nextmsg;
+ nextmsg = ffz(~nextmsg);
+
+ switch (nextmsg) {
+ case IPI_TIMER:
+ ipi_timer(regs);
+ break;
+
+ case IPI_RESCHEDULE:
+ /*
+ * nothing more to do - eveything is
+ * done on the interrupt return path
+ */
+ break;
+
+ case IPI_CALL_FUNC:
+ ipi_call_function(cpu);
+ break;
+
+ case IPI_CPU_STOP:
+ ipi_cpu_stop(cpu);
+ break;
+
+ default:
+ printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
+ cpu, nextmsg);
+ break;
+ }
+ } while (msgs);
+ }
+}
+
+void smp_send_reschedule(int cpu)
+{
+ send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
+}
+
+void smp_send_timer(void)
+{
+ cpumask_t mask = cpu_online_map;
+ cpu_clear(smp_processor_id(), mask);
+ send_ipi_message(mask, IPI_TIMER);
+}
+
+void smp_send_stop(void)
+{
+ cpumask_t mask = cpu_online_map;
+ cpu_clear(smp_processor_id(), mask);
+ send_ipi_message(mask, IPI_CPU_STOP);
+}
+
+/*
+ * not supported here
+ */
+int __init setup_profiling_timer(unsigned int multiplier)
+{
+ return -EINVAL;
+}