Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
---
arch/arm/kernel/topology.c | 113 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 113 insertions(+), 0 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 945b980..053ce9c 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -25,6 +25,11 @@
#include <linux/cpufreq.h>
#endif
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/uaccess.h> /* for copy_from_user */
+#endif
+
#include <asm/cputype.h>
#include <asm/topology.h>
@@ -474,3 +479,111 @@ void init_cpu_topology(void)
}
smp_wmb();
}
+
+/*
+ * debugfs interface for scaling cpu power
+ */
+
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *topo_debugfs_root;
+
+static ssize_t dbg_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *off)
+{
+ unsigned int *value = file->f_dentry->d_inode->i_private;
+ char cdata[128];
+ unsigned long tmp;
+ unsigned int cpu;
+
+ if (size < (sizeof(cdata)-1)) {
+ if (copy_from_user(cdata, buf, size))
+ return -EFAULT;
+ cdata[size] = 0;
+ if (!strict_strtoul(cdata, 10, &tmp)) {
+ *value = tmp;
+
+#ifdef CONFIG_CPU_FREQ
+ for_each_online_cpu(cpu)
+ set_power_scale(cpu, cpu_power[cpu].id);
+#endif
+ }
+ return size;
+ }
+ return -EINVAL;
+}
+
+static ssize_t dbg_read(struct file *file, char __user *buf,
+ size_t size, loff_t *off)
+{
+ unsigned int *value = file->f_dentry->d_inode->i_private;
+ char cdata[128];
+ unsigned int len;
+
+ len = sprintf(cdata, "%u\n", *value);
+ return simple_read_from_buffer(buf, size, off, cdata, len);
+}
+
+static const struct file_operations debugfs_fops = {
+ .read = dbg_read,
+ .write = dbg_write,
+};
+
+static struct dentry *topo_debugfs_register(unsigned int cpu,
+ struct dentry *parent)
+{
+ struct dentry *cpu_d, *d;
+ char cpu_name[16];
+
+ sprintf(cpu_name, "cpu%u", cpu);
+
+ cpu_d = debugfs_create_dir(cpu_name, parent);
+ if (!cpu_d)
+ return NULL;
+
+ d = debugfs_create_file("cpu_power", S_IRUGO | S_IWUGO,
+ cpu_d, &per_cpu(cpu_scale, cpu), &debugfs_fops);
+ if (!d)
+ goto err_out;
+
+#ifdef CONFIG_CPU_FREQ
+ d = debugfs_create_file("scale", S_IRUGO | S_IWUGO,
+ cpu_d, &cpu_power[cpu].id, &debugfs_fops);
+ if (!d)
+ goto err_out;
+
+ d = debugfs_create_file("freq", S_IRUGO,
+ cpu_d, &cpu_power[cpu].freq, &debugfs_fops);
+ if (!d)
+ goto err_out;
+#endif
+ return cpu_d;
+
+err_out:
+ debugfs_remove_recursive(cpu_d);
+ return NULL;
+}
+
+static int __init topo_debugfs_init(void)
+{
+ struct dentry *d;
+ unsigned int cpu;
+
+ d = debugfs_create_dir("cpu_topo", NULL);
+ if (!d)
+ return -ENOMEM;
+ topo_debugfs_root = d;
+
+ for_each_possible_cpu(cpu) {
+ d = topo_debugfs_register(cpu, topo_debugfs_root);
+ if (d == NULL)
+ goto err_out;
+ }
+ return 0;
+
+err_out:
+ debugfs_remove_recursive(topo_debugfs_root);
+ return -ENOMEM;
+}
+
+late_initcall(topo_debugfs_init);
+#endif
--
1.7.4.1
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