[PATCH 2/14] hvc_console: Match vio and console devices using vterm numbers

[Anton Blanchard]

From: Milton Miller <miltonm at bga.com>

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: Milton Miller <miltonm at bga.com>
Signed-off-by: Anton Blanchard <anton at samba.org>

diff -puN drivers/char/hvc_console.c~hvc-console-matching drivers/char/hvc_console.c
--- gr_work_udbg/drivers/char/hvc_console.c~hvc-console-matching	2005-02-08 00:42:37.166135407 -0600
+++ gr_work_udbg-miltonm/drivers/char/hvc_console.c	2005-02-08 00:42:37.177133662 -0600
@@ -102,10 +102,11 @@ static struct list_head hvc_structs = LI
 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, in
 		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);
 
_