Move buffer management into kbd and kbdmux drivers.

These two drivers seem to be the last consumers of clists. clists are
quite overengineered for simple circular buffers, so I'm adding similar
buffer management routines to the kbd and kbdmux drivers. The input
buffer is now part of the softc structures, instead of having
dynamically allocated cblocks.

1 files changed, 42 insertions, 22 deletions

diff --git a/sys/dev/kbdmux/kbdmux.c b/sys/dev/kbdmux/kbdmux.c
index ac6095c..0f1fe42 100644
--- a/sys/dev/kbdmux/kbdmux.c
+++ b/sys/dev/kbdmux/kbdmux.c
@@ -36,7 +36,6 @@
 
 #include <sys/param.h>
 #include <sys/bus.h>
-#include <sys/clist.h>
 #include <sys/conf.h>
 #include <sys/consio.h>
 #include <sys/fcntl.h>
@@ -134,7 +133,9 @@ typedef struct kbdmux_kbd	kbdmux_kbd_t;
  */
 struct kbdmux_state
 {
-	struct clist		 ks_inq;	/* input chars queue */
+	char			 ks_inq[KBDMUX_Q_SIZE]; /* input chars queue */
+	unsigned int		 ks_inq_start;
+	unsigned int		 ks_inq_length;
 	struct task		 ks_task;	/* interrupt task */
 	struct callout		 ks_timo;	/* timeout handler */
 #define TICKS			(hz)		/* rate */
@@ -167,6 +168,34 @@ static task_fn_t		kbdmux_kbd_intr;
 static timeout_t		kbdmux_kbd_intr_timo;
 static kbd_callback_func_t	kbdmux_kbd_event;
 
+static void
+kbdmux_kbd_putc(kbdmux_state_t *state, char c)
+{
+	unsigned int p;
+
+	if (state->ks_inq_length == KBDMUX_Q_SIZE)
+		return;
+
+	p = (state->ks_inq_start + state->ks_inq_length) % KBDMUX_Q_SIZE;
+	state->ks_inq[p] = c;
+	state->ks_inq_length++;
+}
+
+static char
+kbdmux_kbd_getc(kbdmux_state_t *state)
+{
+	char c;
+
+	if (state->ks_inq_length == 0)
+		return (-1);
+
+	c = state->ks_inq[state->ks_inq_start];
+	state->ks_inq_start = (state->ks_inq_start + 1) % KBDMUX_Q_SIZE;
+	state->ks_inq_length--;
+
+	return (c);
+}
+
 /*
  * Interrupt handler task
  */
@@ -205,7 +234,7 @@ kbdmux_kbd_intr_timo(void *xstate)
 	callout_deactivate(&state->ks_timo);
 
 	/* queue interrupt task if needed */
-	if (state->ks_inq.c_cc > 0 && !(state->ks_flags & TASK) &&
+	if (state->ks_inq_length > 0 && !(state->ks_flags & TASK) &&
 	    KBDMUX_QUEUE_INTR(state) == 0)
 		state->ks_flags |= TASK;
 
@@ -246,11 +275,11 @@ kbdmux_kbd_event(keyboard_t *kbd, int event, void *arg)
 			if (!KBD_IS_BUSY(kbd))
 				continue; /* not open - discard the input */
 
-			putc(c, &state->ks_inq);
+			kbdmux_kbd_putc(state, c);
 		}
 
 		/* queue interrupt task if needed */
-		if (state->ks_inq.c_cc > 0 && !(state->ks_flags & TASK) &&
+		if (state->ks_inq_length > 0 && !(state->ks_flags & TASK) &&
 		    KBDMUX_QUEUE_INTR(state) == 0)
 			state->ks_flags |= TASK;
 
@@ -384,8 +413,6 @@ kbdmux_init(int unit, keyboard_t **kbdp, void *arg, int flags)
 		}
 
 		KBDMUX_LOCK_INIT(state);
-		clist_alloc_cblocks(&state->ks_inq,
-				KBDMUX_Q_SIZE, KBDMUX_Q_SIZE / 2);
 		TASK_INIT(&state->ks_task, 0, kbdmux_kbd_intr, (void *) kbd);
 		KBDMUX_CALLOUT_INIT(state);
 		SLIST_INIT(&state->ks_kbds);
@@ -448,10 +475,8 @@ kbdmux_init(int unit, keyboard_t **kbdp, void *arg, int flags)
 	return (0);
 bad:
 	if (needfree) {
-		if (state != NULL) {
-			clist_free_cblocks(&state->ks_inq);
+		if (state != NULL)
 			free(state, M_KBDMUX);
-		}
 		if (keymap != NULL)
 			free(keymap, M_KBDMUX);
 		if (accmap != NULL)
@@ -495,10 +520,6 @@ kbdmux_term(keyboard_t *kbd)
 		free(k, M_KBDMUX);
 	}
 
-	/* flush input queue */
-	ndflush(&state->ks_inq, state->ks_inq.c_cc);
-	clist_free_cblocks(&state->ks_inq);
-
 	KBDMUX_UNLOCK(state);
 
 	kbd_unregister(kbd);
@@ -577,7 +598,7 @@ kbdmux_read(keyboard_t *kbd, int wait)
 	int		 c;
 
 	KBDMUX_LOCK(state);
-	c = getc(&state->ks_inq);
+	c = kbdmux_kbd_getc(state);
 	KBDMUX_UNLOCK(state);
 
 	if (c != -1)
@@ -599,7 +620,7 @@ kbdmux_check(keyboard_t *kbd)
 		return (FALSE);
 
 	KBDMUX_LOCK(state);
-	ready = (state->ks_inq.c_cc > 0)? TRUE : FALSE;
+	ready = (state->ks_inq_length > 0) ? TRUE : FALSE;
 	KBDMUX_UNLOCK(state);
 
 	return (ready);
@@ -635,7 +656,7 @@ next_code:
 	}
 
 	/* see if there is something in the keyboard queue */
-	scancode = getc(&state->ks_inq);
+	scancode = kbdmux_kbd_getc(state);
 	if (scancode == -1) {
 		if (state->ks_flags & POLLING) {
 			kbdmux_kbd_t	*k;
@@ -650,11 +671,11 @@ next_code:
 					if (!KBD_IS_BUSY(k->kbd))
 						continue; 
 
-					putc(scancode, &state->ks_inq);
+					kbdmux_kbd_putc(state, scancode);
 				}
 			}
 
-			if (state->ks_inq.c_cc > 0)
+			if (state->ks_inq_length > 0)
 				goto next_code;
 		}
 
@@ -895,7 +916,7 @@ kbdmux_check_char(keyboard_t *kbd)
 	if (!(state->ks_flags & COMPOSE) && (state->ks_composed_char != 0))
 		ready = TRUE;
 	else
-		ready = (state->ks_inq.c_cc > 0)? TRUE : FALSE;
+		ready = (state->ks_inq_length > 0) ? TRUE : FALSE;
 
 	KBDMUX_UNLOCK(state);
 
@@ -1219,8 +1240,7 @@ kbdmux_clear_state_locked(kbdmux_state_t *state)
 	state->ks_accents = 0;
 	state->ks_composed_char = 0;
 /*	state->ks_prefix = 0;		XXX */
-
-	ndflush(&state->ks_inq, state->ks_inq.c_cc);
+	state->ks_inq_length = 0;
 }
 
 static void