[PATCH] hvc_console: Match vio and console devices using vterm numbers

Use the vterm numbers to match the vio devices being probed with the indices
already allocated via the console initcall function hvc_find_vtys.

The old code required hvc_find_vtys to "guess" the matching devices the vio
subsystem would find and its probe order.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/char/hvc_console.c

@@ -102,10 +102,11 @@ static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
 static DEFINE_SPINLOCK(hvc_structs_lock);
 
 /*
- * This value is used to associate a tty->index value to a hvc_struct based
- * upon order of exposure via hvc_probe().
+ * This value is used to assign a tty->index value to a hvc_struct based
+ * upon order of exposure via hvc_probe(), when we can not match it to
+ * a console canidate registered with hvc_instantiate().
  */
-static int hvc_count = -1;
+static int last_hvc = -1;
 
 /*
  * Do not call this function with either the hvc_strucst_lock or the hvc_struct
@@ -224,9 +225,10 @@ static int __init hvc_console_init(void)
 console_initcall(hvc_console_init);
 
 /*
- * hvc_instantiate() is an early console discovery method which locates consoles
- * prior to the vio subsystem discovering them.  Hotplugged vty adapters do NOT
- * get an hvc_instantiate() callback since the appear after early console init.
+ * hvc_instantiate() is an early console discovery method which locates
+ * consoles * prior to the vio subsystem discovering them.  Hotplugged
+ * vty adapters do NOT get an hvc_instantiate() callback since they
+ * appear after early console init.
  */
 int hvc_instantiate(uint32_t vtermno, int index)
 {
@@ -237,6 +239,11 @@ int hvc_instantiate(uint32_t vtermno, int index)
 		return -1;
 
 	vtermnos[index] = vtermno;
+
+	/* reserve all indices upto and including this index */
+	if (last_hvc < index)
+		last_hvc = index;
+
 	return 0;
 }
 
@@ -697,6 +704,7 @@ static int __devinit hvc_probe(
 		const struct vio_device_id *id)
 {
 	struct hvc_struct *hp;
+	int i;
 
 	/* probed with invalid parameters. */
 	if (!dev || !id)
@@ -717,7 +725,21 @@ static int __devinit hvc_probe(
 
 	spin_lock_init(&hp->lock);
 	spin_lock(&hvc_structs_lock);
-	hp->index = ++hvc_count;
+
+	/*
+	 * find index to use:
+	 * see if this vterm id matches one registered for console.
+	 */
+	for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
+		if (vtermnos[i] == hp->vtermno)
+			break;
+
+	/* no matching slot, just use a counter */
+	if (i >= MAX_NR_HVC_CONSOLES)
+		i = ++last_hvc;
+
+	hp->index = i;
+
 	list_add_tail(&(hp->next), &hvc_structs);
 	spin_unlock(&hvc_structs_lock);