n_smux: add debugfs node for printing channel states
Add debugfs node that prints detailed state information
for all smux channels.
Change-Id: I727f1c53797ee317856056b8e4d9a8686940ce0f
Signed-off-by: Brent Hronik <bhronik@codeaurora.org>
Signed-off-by: Angshuman Sarkar <angshuman@codeaurora.org>
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>
diff --git a/drivers/tty/n_smux.c b/drivers/tty/n_smux.c
index be4db95..20ed9fc 100644
--- a/drivers/tty/n_smux.c
+++ b/drivers/tty/n_smux.c
@@ -178,59 +178,6 @@
SMUX_PWR_OFF_FLUSH,
};
-/**
- * Logical Channel Structure. One instance per channel.
- *
- * Locking Hierarchy
- * Each lock has a postfix that describes the locking level. If multiple locks
- * are required, only increasing lock hierarchy numbers may be locked which
- * ensures avoiding a deadlock.
- *
- * Locking Example
- * If state_lock_lhb1 is currently held and the TX list needs to be
- * manipulated, then tx_lock_lhb2 may be locked since it's locking hierarchy
- * is greater. However, if tx_lock_lhb2 is held, then state_lock_lhb1 may
- * not be acquired since it would result in a deadlock.
- *
- * Note that the Line Discipline locks (*_lha) should always be acquired
- * before the logical channel locks.
- */
-struct smux_lch_t {
- /* channel state */
- spinlock_t state_lock_lhb1;
- uint8_t lcid;
- unsigned local_state;
- unsigned local_mode;
- uint8_t local_tiocm;
- unsigned options;
-
- unsigned remote_state;
- unsigned remote_mode;
- uint8_t remote_tiocm;
-
- int tx_flow_control;
- int rx_flow_control_auto;
- int rx_flow_control_client;
-
- /* client callbacks and private data */
- void *priv;
- void (*notify)(void *priv, int event_type, const void *metadata);
- int (*get_rx_buffer)(void *priv, void **pkt_priv, void **buffer,
- int size);
-
- /* RX Info */
- struct list_head rx_retry_queue;
- unsigned rx_retry_queue_cnt;
- struct delayed_work rx_retry_work;
-
- /* TX Info */
- spinlock_t tx_lock_lhb2;
- struct list_head tx_queue;
- struct list_head tx_ready_list;
- unsigned tx_pending_data_cnt;
- unsigned notify_lwm;
-};
-
union notifier_metadata {
struct smux_meta_disconnected disconnected;
struct smux_meta_read read;
@@ -310,7 +257,7 @@
/* data structures */
-static struct smux_lch_t smux_lch[SMUX_NUM_LOGICAL_CHANNELS];
+struct smux_lch_t smux_lch[SMUX_NUM_LOGICAL_CHANNELS];
static struct smux_ldisc_t smux;
static const char *tty_error_type[] = {
[TTY_NORMAL] = "normal",
@@ -320,7 +267,7 @@
[TTY_FRAME] = "framing",
};
-static const char *smux_cmds[] = {
+static const char * const smux_cmds[] = {
[SMUX_CMD_DATA] = "DATA",
[SMUX_CMD_OPEN_LCH] = "OPEN",
[SMUX_CMD_CLOSE_LCH] = "CLOSE",
@@ -343,8 +290,30 @@
[SMUX_RX_RETRY_LOW_WM_HIT] = "RX_RETRY_LOW_WM_HIT",
};
-static void *log_ctx;
+static const char * const smux_local_state[] = {
+ [SMUX_LCH_LOCAL_CLOSED] = "CLOSED",
+ [SMUX_LCH_LOCAL_OPENING] = "OPENING",
+ [SMUX_LCH_LOCAL_OPENED] = "OPENED",
+ [SMUX_LCH_LOCAL_CLOSING] = "CLOSING",
+};
+static const char * const smux_remote_state[] = {
+ [SMUX_LCH_REMOTE_CLOSED] = "CLOSED",
+ [SMUX_LCH_REMOTE_OPENED] = "OPENED",
+};
+
+static const char * const smux_mode[] = {
+ [SMUX_LCH_MODE_NORMAL] = "N",
+ [SMUX_LCH_MODE_LOCAL_LOOPBACK] = "L",
+ [SMUX_LCH_MODE_REMOTE_LOOPBACK] = "R",
+};
+
+static const char * const smux_undef[] = {
+ [SMUX_UNDEF_LONG] = "UNDEF",
+ [SMUX_UNDEF_SHORT] = "U",
+};
+
+static void *log_ctx;
static void smux_notify_local_fn(struct work_struct *work);
static DECLARE_WORK(smux_notify_local, smux_notify_local_fn);
@@ -370,7 +339,6 @@
static DECLARE_DELAYED_WORK(smux_delayed_inactivity_work,
smux_inactivity_worker);
-static long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch);
static void list_channel(struct smux_lch_t *ch);
static int smux_send_status_cmd(struct smux_lch_t *ch);
static int smux_dispatch_rx_pkt(struct smux_pkt_t *pkt);
@@ -387,6 +355,45 @@
static void smux_pdev_release(struct device *dev);
/**
+ * local_lch_state() - Return human readable form of local logical state.
+ * @state: Local logical channel state enum.
+ *
+ */
+const char *local_lch_state(unsigned state)
+{
+ if (state < ARRAY_SIZE(smux_local_state))
+ return smux_local_state[state];
+ else
+ return smux_undef[SMUX_UNDEF_LONG];
+}
+
+/**
+ * remote_lch_state() - Return human readable for of remote logical state.
+ * @state: Remote logical channel state enum.
+ *
+ */
+const char *remote_lch_state(unsigned state)
+{
+ if (state < ARRAY_SIZE(smux_remote_state))
+ return smux_remote_state[state];
+ else
+ return smux_undef[SMUX_UNDEF_LONG];
+}
+
+/**
+ * lch_mode() - Return human readable form of mode.
+ * @mode: Mode of the logical channel.
+ *
+ */
+const char *lch_mode(unsigned mode)
+{
+ if (mode < ARRAY_SIZE(smux_mode))
+ return smux_mode[mode];
+ else
+ return smux_undef[SMUX_UNDEF_SHORT];
+}
+
+/**
* Convert TTY Error Flags to string for logging purposes.
*
* @flag TTY_* flag
@@ -434,6 +441,9 @@
smux.in_reset = 1;
}
+/**
+ * Initialize the lch_structs.
+ */
static int lch_init(void)
{
unsigned int id;
@@ -3307,7 +3317,7 @@
*
* @returns TIOCM status
*/
-static long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch)
+long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch)
{
long status = 0x0;