as the per-CPU initialization can fail, we need to deal with this
situation in cpufreq_remove_dev as the sysdev core doesn't (yet) do
this for us. The solution: add a "struct cpufreq_policy
*cpufreq_cpu_data[NR_CPUS]" array, which has a NULL pointer for each
CPU not managed by cpufreq (yet) and a pointer to the per-CPU data
for each CPU managed by cpufreq. It is locked by cpufreq_driver_lock.

diff -ruN linux-original/kernel/cpufreq.c linux/kernel/cpufreq.c
--- linux-original/kernel/cpufreq.c	2003-07-12 22:01:26.000000000 +0200
+++ linux/kernel/cpufreq.c	2003-07-12 22:11:50.000000000 +0200
@@ -27,10 +27,11 @@
 
 /**
  * The "cpufreq driver" - the arch- or hardware-dependend low
- * level driver of CPUFreq support, and its spinlock.
- * cpu_max_freq is in kHz.
+ * level driver of CPUFreq support, and its spinlock. This lock
+ * also protects the cpufreq_cpu_data array.
  */
 static struct cpufreq_driver   	*cpufreq_driver;
+static struct cpufreq_policy	*cpufreq_cpu_data[NR_CPUS];
 static spinlock_t		cpufreq_driver_lock = SPIN_LOCK_UNLOCKED;
 
 /* will go away once the locking mess is cleaned up */
@@ -71,7 +72,10 @@
 
 
 	/* get the CPU */
-	data = &cpufreq_driver->policy[cpu];
+	data = cpufreq_cpu_data[cpu];
+
+	if (!data)
+		goto err_out_put_module;
 
 	if (!kobject_get(&data->kobj))
 		goto err_out_put_module;
@@ -352,11 +356,12 @@
 	if (!try_module_get(cpufreq_driver->owner))
 		return -EINVAL;
 
+	policy = &cpufreq_driver->policy[cpu];
+	policy->cpu = cpu;
+
 	/* call driver. From then on the cpufreq must be able
 	 * to accept all calls to ->verify and ->setpolicy for this CPU
 	 */
-	policy = &cpufreq_driver->policy[cpu];
-	policy->cpu = cpu;
 	ret = cpufreq_driver->init(policy);
 	if (ret)
 		goto out;
@@ -386,10 +391,17 @@
 		sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
 		drv_attr++;
 	}
+
+	spin_lock(&cpufreq_driver_lock);
+	cpufreq_cpu_data[cpu] = policy;
+	spin_unlock(&cpufreq_driver_lock);
 	
 	/* set default policy */
 	ret = cpufreq_set_policy(&new_policy);
 	if (ret) {
+		spin_lock(&cpufreq_driver_lock);
+		cpufreq_cpu_data[cpu] = NULL;
+		spin_unlock(&cpufreq_driver_lock);
 		kobject_unregister(&policy->kobj);
 		wait_for_completion(&policy->kobj_unregister);
 	}
@@ -409,6 +421,14 @@
 {
 	unsigned int cpu = sys_dev->id;
 
+	spin_lock(&cpufreq_driver_lock);
+	if (!cpufreq_cpu_data[cpu]) {
+		spin_unlock(&cpufreq_driver_lock);
+		return -EINVAL;
+	}
+	cpufreq_cpu_data[cpu] = NULL;
+	spin_unlock(&cpufreq_driver_lock);
+
 	if (!kobject_get(&cpufreq_driver->policy[cpu].kobj))
 		return -EFAULT;