Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / kernel / power / smp.c

diff --git a/kernel/power/smp.c b/kernel/power/smp.c
index cba3584..5957312 100644 (file)
--- a/kernel/power/smp.c
+++ b/kernel/power/smp.c
@@ -13,73 +13,50 @@
 #include <linux/interrupt.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
+#include <linux/cpu.h>
 #include <asm/atomic.h>
 #include <asm/tlbflush.h>
 
-static atomic_t cpu_counter, freeze;
-
-
-static void smp_pause(void * data)
-{
-       struct saved_context ctxt;
-       __save_processor_state(&ctxt);
-       printk("Sleeping in:\n");
-       dump_stack();
-       atomic_inc(&cpu_counter);
-       while (atomic_read(&freeze)) {
-               /* FIXME: restore takes place at random piece inside this.
-                  This should probably be written in assembly, and
-                  preserve general-purpose registers, too
-
-                  What about stack? We may need to move to new stack here.
-
-                  This should better be ran with interrupts disabled.
-                */
-               cpu_relax();
-               barrier();
-       }
-       atomic_dec(&cpu_counter);
-       __restore_processor_state(&ctxt);
-}
-
-static cpumask_t oldmask;
+/* This is protected by pm_sem semaphore */
+static cpumask_t frozen_cpus;
 
 void disable_nonboot_cpus(void)
 {
-       oldmask = current->cpus_allowed;
-       set_cpus_allowed(current, cpumask_of_cpu(0));
-       printk("Freezing CPUs (at %d)", _smp_processor_id());
-       current->state = TASK_INTERRUPTIBLE;
-       schedule_timeout(HZ);
-       printk("...");
-       BUG_ON(_smp_processor_id() != 0);
-
-       /* FIXME: for this to work, all the CPUs must be running
-        * "idle" thread (or we deadlock). Is that guaranteed? */
-
-       atomic_set(&cpu_counter, 0);
-       atomic_set(&freeze, 1);
-       smp_call_function(smp_pause, NULL, 0, 0);
-       while (atomic_read(&cpu_counter) < (num_online_cpus() - 1)) {
-               cpu_relax();
-               barrier();
+       int cpu, error;
+
+       error = 0;
+       cpus_clear(frozen_cpus);
+       printk("Freezing cpus ...\n");
+       for_each_online_cpu(cpu) {
+               if (cpu == 0)
+                       continue;
+               error = cpu_down(cpu);
+               if (!error) {
+                       cpu_set(cpu, frozen_cpus);
+                       printk("CPU%d is down\n", cpu);
+                       continue;
+               }
+               printk("Error taking cpu %d down: %d\n", cpu, error);
        }
-       printk("ok\n");
+       BUG_ON(raw_smp_processor_id() != 0);
+       if (error)
+               panic("cpus not sleeping");
 }
 
 void enable_nonboot_cpus(void)
 {
-       printk("Restarting CPUs");
-       atomic_set(&freeze, 0);
-       while (atomic_read(&cpu_counter)) {
-               cpu_relax();
-               barrier();
+       int cpu, error;
+
+       printk("Thawing cpus ...\n");
+       for_each_cpu_mask(cpu, frozen_cpus) {
+               error = cpu_up(cpu);
+               if (!error) {
+                       printk("CPU%d is up\n", cpu);
+                       continue;
+               }
+               printk("Error taking cpu %d up: %d\n", cpu, error);
+               panic("Not enough cpus");
        }
-       printk("...");
-       set_cpus_allowed(current, oldmask);
-       schedule();
-       printk("ok\n");
-
+       cpus_clear(frozen_cpus);
 }
 
-