1 files changed, 168 insertions, 0 deletions

diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index 5c090e41d9bb..fa16e54980a1 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -17,6 +17,172 @@
 
 #define DEBUGFS_FORMAT_BUFFER_SIZE 100
 
+#define TX_LATENCY_BIN_DELIMTER_C ','
+#define TX_LATENCY_BIN_DELIMTER_S ","
+#define TX_LATENCY_BINS_DISABLED "enable(bins disabled)\n"
+#define TX_LATENCY_DISABLED "disable\n"
+
+
+/*
+ * Display if Tx latency statistics & bins are enabled/disabled
+ */
+static ssize_t sta_tx_latency_stat_read(struct file *file,
+                                        char __user *userbuf,
+                                        size_t count, loff_t *ppos)
+{
+        struct ieee80211_local *local = file->private_data;
+        struct ieee80211_tx_latency_bin_ranges  *tx_latency;
+        char *buf;
+        int bufsz, i, ret;
+        int pos = 0;
+
+        rcu_read_lock();
+
+        tx_latency = rcu_dereference(local->tx_latency);
+
+        if (tx_latency && tx_latency->n_ranges) {
+                bufsz = tx_latency->n_ranges * 15;
+                buf = kzalloc(bufsz, GFP_ATOMIC);
+                if (!buf)
+                        goto err;
+
+                for (i = 0; i < tx_latency->n_ranges; i++)
+                        pos += scnprintf(buf + pos, bufsz - pos, "%d,",
+                                         tx_latency->ranges[i]);
+                pos += scnprintf(buf + pos, bufsz - pos, "\n");
+        } else if (tx_latency) {
+                bufsz = sizeof(TX_LATENCY_BINS_DISABLED) + 1;
+                buf = kzalloc(bufsz, GFP_ATOMIC);
+                if (!buf)
+                        goto err;
+
+                pos += scnprintf(buf + pos, bufsz - pos, "%s\n",
+                                 TX_LATENCY_BINS_DISABLED);
+        } else {
+                bufsz = sizeof(TX_LATENCY_DISABLED) + 1;
+                buf = kzalloc(bufsz, GFP_ATOMIC);
+                if (!buf)
+                        goto err;
+
+                pos += scnprintf(buf + pos, bufsz - pos, "%s\n",
+                                 TX_LATENCY_DISABLED);
+        }
+
+        rcu_read_unlock();
+
+        ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+        kfree(buf);
+
+        return ret;
+err:
+        rcu_read_unlock();
+        return -ENOMEM;
+}
+
+/*
+ * Receive input from user regarding Tx latency statistics
+ * The input should indicate if Tx latency statistics and bins are
+ * enabled/disabled.
+ * If bins are enabled input should indicate the amount of different bins and
+ * their ranges. Each bin will count how many Tx frames transmitted within the
+ * appropriate latency.
+ * Legal input is:
+ * a) "enable(bins disabled)" - to enable only general statistics
+ * b) "a,b,c,d,...z" - to enable general statistics and bins, where all are
+ * numbers and a < b < c < d.. < z
+ * c) "disable" - disable all statistics
+ * NOTE: must configure Tx latency statistics bins before stations connected.
+ */
+
+static ssize_t sta_tx_latency_stat_write(struct file *file,
+                                         const char __user *userbuf,
+                                         size_t count, loff_t *ppos)
+{
+        struct ieee80211_local *local = file->private_data;
+        char buf[128] = {};
+        char *bins = buf;
+        char *token;
+        int buf_size, i, alloc_size;
+        int prev_bin = 0;
+        int n_ranges = 0;
+        int ret = count;
+        struct ieee80211_tx_latency_bin_ranges  *tx_latency;
+
+        if (sizeof(buf) <= count)
+                return -EINVAL;
+        buf_size = count;
+        if (copy_from_user(buf, userbuf, buf_size))
+                return -EFAULT;
+
+        mutex_lock(&local->sta_mtx);
+
+        /* cannot change config once we have stations */
+        if (local->num_sta)
+                goto unlock;
+
+        tx_latency =
+                rcu_dereference_protected(local->tx_latency,
+                                          lockdep_is_held(&local->sta_mtx));
+
+        /* disable Tx statistics */
+        if (!strcmp(buf, TX_LATENCY_DISABLED)) {
+                if (!tx_latency)
+                        goto unlock;
+                rcu_assign_pointer(local->tx_latency, NULL);
+                synchronize_rcu();
+                kfree(tx_latency);
+                goto unlock;
+        }
+
+        /* Tx latency already enabled */
+        if (tx_latency)
+                goto unlock;
+
+        if (strcmp(TX_LATENCY_BINS_DISABLED, buf)) {
+                /* check how many bins and between what ranges user requested */
+                token = buf;
+                while (*token != '\0') {
+                        if (*token == TX_LATENCY_BIN_DELIMTER_C)
+                                n_ranges++;
+                        token++;
+                }
+                n_ranges++;
+        }
+
+        alloc_size = sizeof(struct ieee80211_tx_latency_bin_ranges) +
+                     n_ranges * sizeof(u32);
+        tx_latency = kzalloc(alloc_size, GFP_ATOMIC);
+        if (!tx_latency) {
+                ret = -ENOMEM;
+                goto unlock;
+        }
+        tx_latency->n_ranges = n_ranges;
+        for (i = 0; i < n_ranges; i++) { /* setting bin ranges */
+                token = strsep(&bins, TX_LATENCY_BIN_DELIMTER_S);
+                sscanf(token, "%d", &tx_latency->ranges[i]);
+                /* bins values should be in ascending order */
+                if (prev_bin >= tx_latency->ranges[i]) {
+                        ret = -EINVAL;
+                        kfree(tx_latency);
+                        goto unlock;
+                }
+                prev_bin = tx_latency->ranges[i];
+        }
+        rcu_assign_pointer(local->tx_latency, tx_latency);
+
+unlock:
+        mutex_unlock(&local->sta_mtx);
+
+        return ret;
+}
+
+static const struct file_operations stats_tx_latency_ops = {
+        .write = sta_tx_latency_stat_write,
+        .read = sta_tx_latency_stat_read,
+        .open = simple_open,
+        .llseek = generic_file_llseek,
+};
+
 int mac80211_format_buffer(char __user *userbuf, size_t count,
                                   loff_t *ppos, char *fmt, ...)
 {
@@ -315,4 +481,6 @@ void debugfs_hw_add(struct ieee80211_local *local)
         DEBUGFS_DEVSTATS_ADD(dot11RTSFailureCount);
         DEBUGFS_DEVSTATS_ADD(dot11FCSErrorCount);
         DEBUGFS_DEVSTATS_ADD(dot11RTSSuccessCount);
+
+        DEBUGFS_DEVSTATS_ADD(tx_latency);
 }