wifi: cfg80211: Add parameters to radio-specific debugfs directories

In multi-radio wiphy architecture, where a single wiphy can have
multiple radios tied to it, radio specific configuration parameters
and global wiphy parameters are maintained for the entire physical
device and common to all radios. But, each radio in a wiphy can
have different values for each radio configuration parameter like
RTS threshold. With the current debugfs directory structure, the
values of global wiphy configuration parameters can be viewed, but,
values of individual radio configuration parameters cannot be viewed.

To address this requirement, maintain separate entries of each radio
configuration parameter i.e., RTS threshold in corresponding radio-
specific debugfs directory. This way, radio-specific configuration
parameters can be maintained along with global wiphy configuration
parameters. Whenever the values are changed for one radio, the values
for rest of the radios in the wiphy and the global wiphy parameter
value will remain intact.

Sample output:
/# iw phy#0 set rts 100 radio 1
/# iw phy#0 set rts 468 radio 0
/# cat /sys/kernel/debug/ieee80211/phy0/rts_threshold
-1
/# cat /sys/kernel/debug/ieee80211/phy0/radio0/radio_rts_threshold
468
/# cat /sys/kernel/debug/ieee80211/phy0/radio1/radio_rts_threshold
100

/# iw phy#0 set rts 500
/# cat /sys/kernel/debug/ieee80211/phy0/rts_threshold
500
/# cat /sys/kernel/debug/ieee80211/phy0/radio0/radio_rts_threshold
500
/# cat /sys/kernel/debug/ieee80211/phy0/radio1/radio_rts_threshold
500

Signed-off-by: Roopni Devanathan <quic_rdevanat@quicinc.com>
Link: https://patch.msgid.link/20251024044649.483557-3-quic_rdevanat@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/net/wireless/debugfs.c b/net/wireless/debugfs.c
index 40e49074e2ee..f9e7fff1ef25 100644
--- a/net/wireless/debugfs.c
+++ b/net/wireless/debugfs.c
@@ -29,6 +29,24 @@ static const struct file_operations name## _ops = {			\
 	.llseek = generic_file_llseek,					\
 }
 
+#define DEBUGFS_RADIO_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_radio_cfg *radio_cfg = 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",
@@ -38,6 +56,9 @@ DEBUGFS_READONLY_FILE(short_retry_limit, 20, "%d",
 DEBUGFS_READONLY_FILE(long_retry_limit, 20, "%d",
 		      wiphy->retry_long);
 
+DEBUGFS_RADIO_READONLY_FILE(radio_rts_threshold, 20, "%d",
+			    radio_cfg->rts_threshold);
+
 static int ht_print_chan(struct ieee80211_channel *chan,
 			 char *buf, int buf_size, int offset)
 {
@@ -100,15 +121,27 @@ static const struct file_operations ht40allow_map_ops = {
 #define DEBUGFS_ADD(name)						\
 	debugfs_create_file(#name, 0444, phyd, &rdev->wiphy, &name## _ops)
 
+#define DEBUGFS_RADIO_ADD(name, radio_idx)				\
+	debugfs_create_file(#name, 0444, radiod,			\
+			    &rdev->wiphy.radio_cfg[radio_idx],		\
+			    &name## _ops)
+
 void cfg80211_debugfs_rdev_add(struct cfg80211_registered_device *rdev)
 {
 	struct dentry *phyd = rdev->wiphy.debugfsdir;
+	struct dentry *radiod;
+	u8 i;
 
 	DEBUGFS_ADD(rts_threshold);
 	DEBUGFS_ADD(fragmentation_threshold);
 	DEBUGFS_ADD(short_retry_limit);
 	DEBUGFS_ADD(long_retry_limit);
 	DEBUGFS_ADD(ht40allow_map);
+
+	for (i = 0; i < rdev->wiphy.n_radio; i++) {
+		radiod = rdev->wiphy.radio_cfg[i].radio_debugfsdir;
+		DEBUGFS_RADIO_ADD(radio_rts_threshold, i);
+	}
 }
 
 struct debugfs_read_work {