[PATCH] i386 CPU hotplug

[safe/jmp/linux-2.6] / arch / i386 / kernel / process.c

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 2468ab7..c1b11e8 100644 (file)
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -13,6 +13,7 @@
 
 #include <stdarg.h>
 
+#include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/fs.h>
@@ -37,6 +38,7 @@
 #include <linux/kallsyms.h>
 #include <linux/ptrace.h>
 #include <linux/random.h>
+#include <linux/kprobes.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -54,6 +56,9 @@
 #include <linux/irq.h>
 #include <linux/err.h>
 
+#include <asm/tlbflush.h>
+#include <asm/cpu.h>
+
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 static int hlt_counter;
@@ -142,14 +147,44 @@ static void poll_idle (void)
        }
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+#include <asm/nmi.h>
+/* We don't actually take CPU down, just spin without interrupts. */
+static inline void play_dead(void)
+{
+       /* Ack it */
+       __get_cpu_var(cpu_state) = CPU_DEAD;
+
+       /* We shouldn't have to disable interrupts while dead, but
+        * some interrupts just don't seem to go away, and this makes
+        * it "work" for testing purposes. */
+       /* Death loop */
+       while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
+               cpu_relax();
+
+       local_irq_disable();
+       __flush_tlb_all();
+       cpu_set(smp_processor_id(), cpu_online_map);
+       enable_APIC_timer();
+       local_irq_enable();
+}
+#else
+static inline void play_dead(void)
+{
+       BUG();
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
 /*
  * The idle thread. There's no useful work to be
  * done, so just try to conserve power and have a
  * low exit latency (ie sit in a loop waiting for
  * somebody to say that they'd like to reschedule)
  */
-void cpu_idle (void)
+void cpu_idle(void)
 {
+       int cpu = raw_smp_processor_id();
+
        /* endless idle loop with no priority at all */
        while (1) {
                while (!need_resched()) {
@@ -164,6 +199,9 @@ void cpu_idle (void)
                        if (!idle)
                                idle = default_idle;
 
+                       if (cpu_is_offline(cpu))
+                               play_dead();
+
                        __get_cpu_var(irq_stat).idle_timestamp = jiffies;
                        idle();
                }
@@ -266,7 +304,7 @@ void show_regs(struct pt_regs * regs)
        printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id());
        print_symbol("EIP is at %s\n", regs->eip);
 
-       if (regs->xcs & 3)
+       if (user_mode(regs))
                printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
        printk(" EFLAGS: %08lx    %s  (%s)\n",
               regs->eflags, print_tainted(), system_utsname.release);
@@ -339,6 +377,13 @@ void exit_thread(void)
        struct task_struct *tsk = current;
        struct thread_struct *t = &tsk->thread;
 
+       /*
+        * Remove function-return probe instances associated with this task
+        * and put them back on the free list. Do not insert an exit probe for
+        * this function, it will be disabled by kprobe_flush_task if you do.
+        */
+       kprobe_flush_task(tsk);
+
        /* The process may have allocated an io port bitmap... nuke it. */
        if (unlikely(NULL != t->io_bitmap_ptr)) {
                int cpu = get_cpu();
@@ -362,6 +407,13 @@ void flush_thread(void)
 {
        struct task_struct *tsk = current;
 
+       /*
+        * Remove function-return probe instances associated with this task
+        * and put them back on the free list. Do not insert an exit probe for
+        * this function, it will be disabled by kprobe_flush_task if you do.
+        */
+       kprobe_flush_task(tsk);
+
        memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
        memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));        
        /*