Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 207 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
new file mode 100644
index 0000000..d32bf35
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -0,0 +1,207 @@
+/*
+ *  linux/drivers/cpufreq/cpufreq_userspace.c
+ *
+ *  Copyright (C)  2001 Russell King
+ *            (C)  2002 - 2004 Dominik Brodowski <linux@brodo.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/cpufreq.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+
+#include <asm/uaccess.h>
+
+
+/**
+ * A few values needed by the userspace governor
+ */
+static unsigned int	cpu_max_freq[NR_CPUS];
+static unsigned int	cpu_min_freq[NR_CPUS];
+static unsigned int	cpu_cur_freq[NR_CPUS]; /* current CPU freq */
+static unsigned int	cpu_set_freq[NR_CPUS]; /* CPU freq desired by userspace */
+static unsigned int	cpu_is_managed[NR_CPUS];
+static struct cpufreq_policy current_policy[NR_CPUS];
+
+static DECLARE_MUTEX	(userspace_sem); 
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg)
+
+/* keep track of frequency transitions */
+static int 
+userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+                       void *data)
+{
+        struct cpufreq_freqs *freq = data;
+
+	dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n", freq->cpu, freq->new);
+	cpu_cur_freq[freq->cpu] = freq->new;
+
+        return 0;
+}
+
+static struct notifier_block userspace_cpufreq_notifier_block = {
+        .notifier_call  = userspace_cpufreq_notifier
+};
+
+
+/** 
+ * cpufreq_set - set the CPU frequency
+ * @freq: target frequency in kHz
+ * @cpu: CPU for which the frequency is to be set
+ *
+ * Sets the CPU frequency to freq.
+ */
+static int cpufreq_set(unsigned int freq, unsigned int cpu)
+{
+	int ret = -EINVAL;
+
+	dprintk("cpufreq_set for cpu %u, freq %u kHz\n", cpu, freq);
+
+	down(&userspace_sem);
+	if (!cpu_is_managed[cpu])
+		goto err;
+
+	cpu_set_freq[cpu] = freq;
+
+	if (freq < cpu_min_freq[cpu])
+		freq = cpu_min_freq[cpu];
+	if (freq > cpu_max_freq[cpu])
+		freq = cpu_max_freq[cpu];
+
+	/*
+	 * We're safe from concurrent calls to ->target() here
+	 * as we hold the userspace_sem lock. If we were calling
+	 * cpufreq_driver_target, a deadlock situation might occur:
+	 * A: cpufreq_set (lock userspace_sem) -> cpufreq_driver_target(lock policy->lock)
+	 * B: cpufreq_set_policy(lock policy->lock) -> __cpufreq_governor -> cpufreq_governor_userspace (lock userspace_sem)
+	 */
+	ret = __cpufreq_driver_target(&current_policy[cpu], freq, 
+	      CPUFREQ_RELATION_L);
+
+ err:
+	up(&userspace_sem);
+	return ret;
+}
+
+
+/************************** sysfs interface ************************/
+static ssize_t show_speed (struct cpufreq_policy *policy, char *buf)
+{
+	return sprintf (buf, "%u\n", cpu_cur_freq[policy->cpu]);
+}
+
+static ssize_t 
+store_speed (struct cpufreq_policy *policy, const char *buf, size_t count) 
+{
+	unsigned int freq = 0;
+	unsigned int ret;
+
+	ret = sscanf (buf, "%u", &freq);
+	if (ret != 1)
+		return -EINVAL;
+
+	cpufreq_set(freq, policy->cpu);
+
+	return count;
+}
+
+static struct freq_attr freq_attr_scaling_setspeed = 
+{
+	.attr = { .name = "scaling_setspeed", .mode = 0644, .owner = THIS_MODULE },
+	.show = show_speed,
+	.store = store_speed,
+};
+
+static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
+				   unsigned int event)
+{
+	unsigned int cpu = policy->cpu;
+	switch (event) {
+	case CPUFREQ_GOV_START:
+		if (!cpu_online(cpu))
+			return -EINVAL;
+		BUG_ON(!policy->cur);
+		down(&userspace_sem);
+		cpu_is_managed[cpu] = 1;		
+		cpu_min_freq[cpu] = policy->min;
+		cpu_max_freq[cpu] = policy->max;
+		cpu_cur_freq[cpu] = policy->cur;
+		cpu_set_freq[cpu] = policy->cur;
+		sysfs_create_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
+		memcpy (&current_policy[cpu], policy, sizeof(struct cpufreq_policy));
+		dprintk("managing cpu %u started (%u - %u kHz, currently %u kHz)\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu]);
+		up(&userspace_sem);
+		break;
+	case CPUFREQ_GOV_STOP:
+		down(&userspace_sem);
+		cpu_is_managed[cpu] = 0;
+		cpu_min_freq[cpu] = 0;
+		cpu_max_freq[cpu] = 0;
+		cpu_set_freq[cpu] = 0;
+		sysfs_remove_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
+		dprintk("managing cpu %u stopped\n", cpu);
+		up(&userspace_sem);
+		break;
+	case CPUFREQ_GOV_LIMITS:
+		down(&userspace_sem);
+		cpu_min_freq[cpu] = policy->min;
+		cpu_max_freq[cpu] = policy->max;
+		dprintk("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n", cpu, cpu_min_freq[cpu], cpu_max_freq[cpu], cpu_cur_freq[cpu], cpu_set_freq[cpu]);
+		if (policy->max < cpu_set_freq[cpu]) {
+			__cpufreq_driver_target(&current_policy[cpu], policy->max, 
+			      CPUFREQ_RELATION_H);
+		} else if (policy->min > cpu_set_freq[cpu]) {
+			__cpufreq_driver_target(&current_policy[cpu], policy->min, 
+			      CPUFREQ_RELATION_L);
+		} else {
+			__cpufreq_driver_target(&current_policy[cpu], cpu_set_freq[cpu],
+			      CPUFREQ_RELATION_L);
+		}
+		memcpy (&current_policy[cpu], policy, sizeof(struct cpufreq_policy));
+		up(&userspace_sem);
+		break;
+	}
+	return 0;
+}
+
+
+struct cpufreq_governor cpufreq_gov_userspace = {
+	.name		= "userspace",
+	.governor	= cpufreq_governor_userspace,
+	.owner		= THIS_MODULE,
+};
+EXPORT_SYMBOL(cpufreq_gov_userspace);
+
+static int __init cpufreq_gov_userspace_init(void)
+{
+	cpufreq_register_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
+	return cpufreq_register_governor(&cpufreq_gov_userspace);
+}
+
+
+static void __exit cpufreq_gov_userspace_exit(void)
+{
+	cpufreq_unregister_governor(&cpufreq_gov_userspace);
+        cpufreq_unregister_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+
+MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>, Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION ("CPUfreq policy governor 'userspace'");
+MODULE_LICENSE ("GPL");
+
+fs_initcall(cpufreq_gov_userspace_init);
+module_exit(cpufreq_gov_userspace_exit);