v4.19.13 snapshot.
diff --git a/net/wireless/debugfs.c b/net/wireless/debugfs.c
new file mode 100644
index 0000000..30fc6eb
--- /dev/null
+++ b/net/wireless/debugfs.c
@@ -0,0 +1,117 @@
+/*
+ * cfg80211 debugfs
+ *
+ * Copyright 2009 Luis R. Rodriguez <lrodriguez@atheros.com>
+ * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
+ *
+ * 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/slab.h>
+#include "core.h"
+#include "debugfs.h"
+
+#define DEBUGFS_READONLY_FILE(name, buflen, fmt, value...) \
+static ssize_t name## _read(struct file *file, char __user *userbuf, \
+ size_t count, loff_t *ppos) \
+{ \
+ struct wiphy *wiphy = file->private_data; \
+ char buf[buflen]; \
+ int res; \
+ \
+ res = scnprintf(buf, buflen, fmt "\n", ##value); \
+ return simple_read_from_buffer(userbuf, count, ppos, buf, res); \
+} \
+ \
+static const struct file_operations name## _ops = { \
+ .read = name## _read, \
+ .open = simple_open, \
+ .llseek = generic_file_llseek, \
+}
+
+DEBUGFS_READONLY_FILE(rts_threshold, 20, "%d",
+ wiphy->rts_threshold);
+DEBUGFS_READONLY_FILE(fragmentation_threshold, 20, "%d",
+ wiphy->frag_threshold);
+DEBUGFS_READONLY_FILE(short_retry_limit, 20, "%d",
+ wiphy->retry_short);
+DEBUGFS_READONLY_FILE(long_retry_limit, 20, "%d",
+ wiphy->retry_long);
+
+static int ht_print_chan(struct ieee80211_channel *chan,
+ char *buf, int buf_size, int offset)
+{
+ if (WARN_ON(offset > buf_size))
+ return 0;
+
+ if (chan->flags & IEEE80211_CHAN_DISABLED)
+ return scnprintf(buf + offset,
+ buf_size - offset,
+ "%d Disabled\n",
+ chan->center_freq);
+
+ return scnprintf(buf + offset,
+ buf_size - offset,
+ "%d HT40 %c%c\n",
+ chan->center_freq,
+ (chan->flags & IEEE80211_CHAN_NO_HT40MINUS) ?
+ ' ' : '-',
+ (chan->flags & IEEE80211_CHAN_NO_HT40PLUS) ?
+ ' ' : '+');
+}
+
+static ssize_t ht40allow_map_read(struct file *file,
+ char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct wiphy *wiphy = file->private_data;
+ char *buf;
+ unsigned int offset = 0, buf_size = PAGE_SIZE, i, r;
+ enum nl80211_band band;
+ struct ieee80211_supported_band *sband;
+
+ buf = kzalloc(buf_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ rtnl_lock();
+
+ for (band = 0; band < NUM_NL80211_BANDS; band++) {
+ sband = wiphy->bands[band];
+ if (!sband)
+ continue;
+ for (i = 0; i < sband->n_channels; i++)
+ offset += ht_print_chan(&sband->channels[i],
+ buf, buf_size, offset);
+ }
+
+ rtnl_unlock();
+
+ r = simple_read_from_buffer(user_buf, count, ppos, buf, offset);
+
+ kfree(buf);
+
+ return r;
+}
+
+static const struct file_operations ht40allow_map_ops = {
+ .read = ht40allow_map_read,
+ .open = simple_open,
+ .llseek = default_llseek,
+};
+
+#define DEBUGFS_ADD(name) \
+ debugfs_create_file(#name, 0444, phyd, &rdev->wiphy, &name## _ops)
+
+void cfg80211_debugfs_rdev_add(struct cfg80211_registered_device *rdev)
+{
+ struct dentry *phyd = rdev->wiphy.debugfsdir;
+
+ DEBUGFS_ADD(rts_threshold);
+ DEBUGFS_ADD(fragmentation_threshold);
+ DEBUGFS_ADD(short_retry_limit);
+ DEBUGFS_ADD(long_retry_limit);
+ DEBUGFS_ADD(ht40allow_map);
+}