1 files changed, 253 insertions, 0 deletions

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
new file mode 100644
index 000000000000..b662300a88f3
--- /dev/null
+++ b/arch/x86/kernel/smp.c
@@ -0,0 +1,253 @@
+#include <linux/init.h>
+
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/kernel_stat.h>
+#include <linux/mc146818rtc.h>
+#include <linux/cache.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+
+#include <asm/mtrr.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/proto.h>
+#ifdef CONFIG_X86_32
+#include <mach_apic.h>
+#include <mach_ipi.h>
+#else
+#include <asm/mach_apic.h>
+#endif
+
+/*
+ * this function sends a 'reschedule' IPI to another CPU.
+ * it goes straight through and wastes no time serializing
+ * anything. Worst case is that we lose a reschedule ...
+ */
+static void native_smp_send_reschedule(int cpu)
+{
+        WARN_ON(cpu_is_offline(cpu));
+        send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
+}
+
+/*
+ * Structure and data for smp_call_function(). This is designed to minimise
+ * static memory requirements. It also looks cleaner.
+ */
+static DEFINE_SPINLOCK(call_lock);
+
+struct call_data_struct {
+        void (*func) (void *info);
+        void *info;
+        atomic_t started;
+        atomic_t finished;
+        int wait;
+};
+
+void lock_ipi_call_lock(void)
+{
+        spin_lock_irq(&call_lock);
+}
+
+void unlock_ipi_call_lock(void)
+{
+        spin_unlock_irq(&call_lock);
+}
+
+static struct call_data_struct *call_data;
+
+static void __smp_call_function(void (*func) (void *info), void *info,
+                                int nonatomic, int wait)
+{
+        struct call_data_struct data;
+        int cpus = num_online_cpus() - 1;
+
+        if (!cpus)
+                return;
+
+        data.func = func;
+        data.info = info;
+        atomic_set(&data.started, 0);
+        data.wait = wait;
+        if (wait)
+                atomic_set(&data.finished, 0);
+
+        call_data = &data;
+        mb();
+
+        /* Send a message to all other CPUs and wait for them to respond */
+        send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+
+        /* Wait for response */
+        while (atomic_read(&data.started) != cpus)
+                cpu_relax();
+
+        if (wait)
+                while (atomic_read(&data.finished) != cpus)
+                        cpu_relax();
+}
+
+
+/**
+ * smp_call_function_mask(): Run a function on a set of other CPUs.
+ * @mask: The set of cpus to run on.  Must not include the current cpu.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ *
+  * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+static int
+native_smp_call_function_mask(cpumask_t mask,
+                              void (*func)(void *), void *info,
+                              int wait)
+{
+        struct call_data_struct data;
+        cpumask_t allbutself;
+        int cpus;
+
+        /* Can deadlock when called with interrupts disabled */
+        WARN_ON(irqs_disabled());
+
+        /* Holding any lock stops cpus from going down. */
+        spin_lock(&call_lock);
+
+        allbutself = cpu_online_map;
+        cpu_clear(smp_processor_id(), allbutself);
+
+        cpus_and(mask, mask, allbutself);
+        cpus = cpus_weight(mask);
+
+        if (!cpus) {
+                spin_unlock(&call_lock);
+                return 0;
+        }
+
+        data.func = func;
+        data.info = info;
+        atomic_set(&data.started, 0);
+        data.wait = wait;
+        if (wait)
+                atomic_set(&data.finished, 0);
+
+        call_data = &data;
+        wmb();
+
+        /* Send a message to other CPUs */
+        if (cpus_equal(mask, allbutself))
+                send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+        else
+                send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
+
+        /* Wait for response */
+        while (atomic_read(&data.started) != cpus)
+                cpu_relax();
+
+        if (wait)
+                while (atomic_read(&data.finished) != cpus)
+                        cpu_relax();
+        spin_unlock(&call_lock);
+
+        return 0;
+}
+
+static void stop_this_cpu(void *dummy)
+{
+        local_irq_disable();
+        /*
+         * Remove this CPU:
+         */
+        cpu_clear(smp_processor_id(), cpu_online_map);
+        disable_local_APIC();
+        if (hlt_works(smp_processor_id()))
+                for (;;) halt();
+        for (;;);
+}
+
+/*
+ * this function calls the 'stop' function on all other CPUs in the system.
+ */
+
+static void native_smp_send_stop(void)
+{
+        int nolock;
+        unsigned long flags;
+
+        if (reboot_force)
+                return;
+
+        /* Don't deadlock on the call lock in panic */
+        nolock = !spin_trylock(&call_lock);
+        local_irq_save(flags);
+        __smp_call_function(stop_this_cpu, NULL, 0, 0);
+        if (!nolock)
+                spin_unlock(&call_lock);
+        disable_local_APIC();
+        local_irq_restore(flags);
+}
+
+/*
+ * Reschedule call back. Nothing to do,
+ * all the work is done automatically when
+ * we return from the interrupt.
+ */
+void smp_reschedule_interrupt(struct pt_regs *regs)
+{
+        ack_APIC_irq();
+#ifdef CONFIG_X86_32
+        __get_cpu_var(irq_stat).irq_resched_count++;
+#else
+        add_pda(irq_resched_count, 1);
+#endif
+}
+
+void smp_call_function_interrupt(struct pt_regs *regs)
+{
+        void (*func) (void *info) = call_data->func;
+        void *info = call_data->info;
+        int wait = call_data->wait;
+
+        ack_APIC_irq();
+        /*
+         * Notify initiating CPU that I've grabbed the data and am
+         * about to execute the function
+         */
+        mb();
+        atomic_inc(&call_data->started);
+        /*
+         * At this point the info structure may be out of scope unless wait==1
+         */
+        irq_enter();
+        (*func)(info);
+#ifdef CONFIG_X86_32
+        __get_cpu_var(irq_stat).irq_call_count++;
+#else
+        add_pda(irq_call_count, 1);
+#endif
+        irq_exit();
+
+        if (wait) {
+                mb();
+                atomic_inc(&call_data->finished);
+        }
+}
+
+struct smp_ops smp_ops = {
+        .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
+        .smp_prepare_cpus = native_smp_prepare_cpus,
+        .cpu_up = native_cpu_up,
+        .smp_cpus_done = native_smp_cpus_done,
+
+        .smp_send_stop = native_smp_send_stop,
+        .smp_send_reschedule = native_smp_send_reschedule,
+        .smp_call_function_mask = native_smp_call_function_mask,
+};
+EXPORT_SYMBOL_GPL(smp_ops);
+