[PATCH v8 4/8] interconnect: Add debugfs support

[Georgi Djakov]

Add a functionality to provide information about the current constraints
per each node and provider.

Signed-off-by: Georgi Djakov <georgi.dja...@linaro.org>
Reviewed-by: Evan Green <evgr...@chromium.org>
---
 drivers/interconnect/core.c | 78 +++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 8f874d1b0a0f..288ef83c3bc0 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -6,6 +6,7 @@
  * Author: Georgi Djakov <georgi.dja...@linaro.org>
  */
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/init.h>
@@ -17,10 +18,12 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/overflow.h>
+#include <linux/uaccess.h>
 
 static DEFINE_IDR(icc_idr);
 static LIST_HEAD(icc_provider_list);
 static DEFINE_MUTEX(icc_lock);
+static struct dentry *icc_debugfs_dir;
 
 /**
  * struct icc_req - constraints that are attached to each node
@@ -49,6 +52,62 @@ struct icc_path {
        struct icc_req reqs[];
 };
 
+#ifdef CONFIG_DEBUG_FS
+
+static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
+{
+       if (!n)
+               return;
+
+       seq_printf(s, "%-30s %12d %12d\n",
+                  n->name, n->avg_bw, n->peak_bw);
+}
+
+static int icc_summary_show(struct seq_file *s, void *data)
+{
+       struct icc_provider *provider;
+
+       seq_puts(s, " node                                   avg         
peak\n");
+       seq_puts(s, 
"--------------------------------------------------------\n");
+
+       mutex_lock(&icc_lock);
+
+       list_for_each_entry(provider, &icc_provider_list, provider_list) {
+               struct icc_node *n;
+
+               list_for_each_entry(n, &provider->nodes, node_list) {
+                       struct icc_req *r;
+
+                       icc_summary_show_one(s, n);
+                       hlist_for_each_entry(r, &n->req_list, req_node) {
+                               if (!r->dev)
+                                       continue;
+
+                               seq_printf(s, "    %-26s %12d %12d\n",
+                                          dev_name(r->dev), r->avg_bw,
+                                          r->peak_bw);
+                       }
+               }
+       }
+
+       mutex_unlock(&icc_lock);
+
+       return 0;
+}
+
+static int icc_summary_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, icc_summary_show, inode->i_private);
+}
+
+static const struct file_operations icc_summary_fops = {
+       .open           = icc_summary_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+#endif
+
 static struct icc_node *node_find(const int id)
 {
        return idr_find(&icc_idr, id);
@@ -646,6 +705,25 @@ int icc_provider_del(struct icc_provider *provider)
 }
 EXPORT_SYMBOL_GPL(icc_provider_del);
 
+static int __init icc_init(void)
+{
+#ifdef CONFIG_DEBUG_FS
+       icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
+       debugfs_create_file("interconnect_summary", 0444,
+                           icc_debugfs_dir, NULL, &icc_summary_fops);
+#endif
+       return 0;
+}
+
+static void __exit icc_exit(void)
+{
+#ifdef CONFIG_DEBUG_FS
+       debugfs_remove_recursive(icc_debugfs_dir);
+#endif
+}
+module_init(icc_init);
+module_exit(icc_exit);
+
 MODULE_AUTHOR("Georgi Djakov <georgi.dja...@linaro.org");
 MODULE_DESCRIPTION("Interconnect Driver Core");
 MODULE_LICENSE("GPL v2");