Fix resume regression caused by changes in 2.6.25 cpuidle code

1 files changed, 146 insertions, 0 deletions

diff --git a/patches/revert-cpuidle-simplification.patch b/patches/revert-cpuidle-simplification.patch
new file mode 100644
index 0000000..cec5196
--- /dev/null
+++ b/patches/revert-cpuidle-simplification.patch
@@ -0,0 +1,146 @@
+reverted:
+--- b/arch/x86/kernel/process_32.c
++++ a/arch/x86/kernel/process_32.c
+@@ -82,6 +82,7 @@
+  */
+ void (*pm_idle)(void);
+ EXPORT_SYMBOL(pm_idle);
++static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
+ 
+ void disable_hlt(void)
+ {
+@@ -189,6 +190,9 @@
+ 		while (!need_resched()) {
+ 			void (*idle)(void);
+ 
++			if (__get_cpu_var(cpu_idle_state))
++				__get_cpu_var(cpu_idle_state) = 0;
++
+ 			check_pgt_cache();
+ 			rmb();
+ 			idle = pm_idle;
+@@ -216,19 +220,40 @@
+ {
+ }
+ 
+-/*
+- * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+- * pm_idle and update to new pm_idle value. Required while changing pm_idle
+- * handler on SMP systems.
+- *
+- * Caller must have changed pm_idle to the new value before the call. Old
+- * pm_idle value will not be used by any CPU after the return of this function.
+- */
+ void cpu_idle_wait(void)
+ {
++	unsigned int cpu, this_cpu = get_cpu();
++	cpumask_t map, tmp = current->cpus_allowed;
++
++	set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
++	put_cpu();
++
++	cpus_clear(map);
++	for_each_online_cpu(cpu) {
++		per_cpu(cpu_idle_state, cpu) = 1;
++		cpu_set(cpu, map);
++	}
++
++	__get_cpu_var(cpu_idle_state) = 0;
++
++	wmb();
++	do {
++		ssleep(1);
++		for_each_online_cpu(cpu) {
++			if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
++				cpu_clear(cpu, map);
++		}
++		cpus_and(map, map, cpu_online_map);
++		/*
++		 * We waited 1 sec, if a CPU still did not call idle
++		 * it may be because it is in idle and not waking up
++		 * because it has nothing to do.
++		 * Give all the remaining CPUS a kick.
++		 */
++		smp_call_function_mask(map, do_nothing, NULL, 0);
++	} while (!cpus_empty(map));
++
++	set_cpus_allowed(current, tmp);
+-	smp_mb();
+-	/* kick all the CPUs so that they exit out of pm_idle */
+-	smp_call_function(do_nothing, NULL, 0, 1);
+ }
+ EXPORT_SYMBOL_GPL(cpu_idle_wait);
+ 
+reverted:
+--- b/arch/x86/kernel/process_64.c
++++ a/arch/x86/kernel/process_64.c
+@@ -63,6 +63,7 @@
+  */
+ void (*pm_idle)(void);
+ EXPORT_SYMBOL(pm_idle);
++static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
+ 
+ static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+ 
+@@ -172,6 +173,9 @@
+ 		while (!need_resched()) {
+ 			void (*idle)(void);
+ 
++			if (__get_cpu_var(cpu_idle_state))
++				__get_cpu_var(cpu_idle_state) = 0;
++
+ 			rmb();
+ 			idle = pm_idle;
+ 			if (!idle)
+@@ -203,19 +207,40 @@
+ {
+ }
+ 
+-/*
+- * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+- * pm_idle and update to new pm_idle value. Required while changing pm_idle
+- * handler on SMP systems.
+- *
+- * Caller must have changed pm_idle to the new value before the call. Old
+- * pm_idle value will not be used by any CPU after the return of this function.
+- */
+ void cpu_idle_wait(void)
+ {
++	unsigned int cpu, this_cpu = get_cpu();
++	cpumask_t map, tmp = current->cpus_allowed;
++
++	set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
++	put_cpu();
++
++	cpus_clear(map);
++	for_each_online_cpu(cpu) {
++		per_cpu(cpu_idle_state, cpu) = 1;
++		cpu_set(cpu, map);
++	}
++
++	__get_cpu_var(cpu_idle_state) = 0;
++
++	wmb();
++	do {
++		ssleep(1);
++		for_each_online_cpu(cpu) {
++			if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
++				cpu_clear(cpu, map);
++		}
++		cpus_and(map, map, cpu_online_map);
++		/*
++		 * We waited 1 sec, if a CPU still did not call idle
++		 * it may be because it is in idle and not waking up
++		 * because it has nothing to do.
++		 * Give all the remaining CPUS a kick.
++		 */
++		smp_call_function_mask(map, do_nothing, 0, 0);
++	} while (!cpus_empty(map));
++
++	set_cpus_allowed(current, tmp);
+-	smp_mb();
+-	/* kick all the CPUs so that they exit out of pm_idle */
+-	smp_call_function(do_nothing, NULL, 0, 1);
+ }
+ EXPORT_SYMBOL_GPL(cpu_idle_wait);
+