Queue: Add functionality needed by new USART stream driver

Previously there was no way to remove multiple units at a time
from the queue, and the queue was wasting an entry to disambiguate
full from empty.  There was also no way to get the free entry
count from the queue, only the ability to query if it was above
a required amount.  The queue was also storing its constant
compile time configuration as well as its dynamic state in the
same structure.  This wasted RAM on configuration information
that doesn't change.

This refactor fixes these issues, making the queue suitable for
use in the new USART stream driver.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
TEST=make buildall -j

Change-Id: I284cee52d8189928dbc4c499f87ab34e14019e5a
Reviewed-on: https://chromium-review.googlesource.com/210533
Reviewed-by: Vic Yang <victoryang@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>
Tested-by: Anton Staaf <robotboy@chromium.org>

1 files changed, 28 insertions, 26 deletions

diff --git a/common/keyboard_8042.c b/common/keyboard_8042.c
index 9a87f5257f..217bf52339 100644
--- a/common/keyboard_8042.c
+++ b/common/keyboard_8042.c
@@ -68,12 +68,7 @@ enum scancode_set_list {
  */
 static struct mutex to_host_mutex;
 
-static uint8_t to_host_buffer[16];
-static struct queue to_host = {
-	.buf_bytes  = sizeof(to_host_buffer),
-	.unit_bytes = sizeof(uint8_t),
-	.buf        = to_host_buffer,
-};
+QUEUE_CONFIG(to_host, 16, uint8_t);
 
 /* Queue command/data from the host */
 enum {
@@ -96,12 +91,7 @@ struct host_byte {
  *
  * Hence, 5 (actually 4 plus one spare) is large enough, but use 8 for safety.
  */
-static uint8_t from_host_buffer[8 * sizeof(struct host_byte)];
-static struct queue from_host = {
-	.buf_bytes  = sizeof(from_host_buffer),
-	.unit_bytes = sizeof(struct host_byte),
-	.buf        = from_host_buffer,
-};
+QUEUE_CONFIG(from_host, 8, struct host_byte);
 
 static int i8042_irq_enabled;
 
@@ -235,6 +225,11 @@ struct kblog_t {
 	 *
 	 * k = to-host queue head pointer before byte dequeued
 	 * K = byte actually sent to host via LPC
+	 *
+	 * The to-host head and tail pointers are logged pre-wrapping to the
+	 * queue size.  This means that they continually increment as units
+	 * are dequeued and enqueued respectively.  Since only the bottom
+	 * byte of the value is logged they will wrap every 256 units.
 	 */
 	uint8_t type;
 	uint8_t byte;
@@ -263,7 +258,7 @@ void keyboard_host_write(int data, int is_cmd)
 
 	h.type = is_cmd ? HOST_COMMAND : HOST_DATA;
 	h.byte = data;
-	queue_add_units(&from_host, &h, 1);
+	queue_add_unit(&from_host, &h);
 	task_wake(TASK_ID_KEYPROTO);
 }
 
@@ -300,8 +295,8 @@ static void i8042_send_to_host(int len, const uint8_t *bytes)
 
 	/* Enqueue output data if there's space */
 	mutex_lock(&to_host_mutex);
-	if (queue_has_space(&to_host, len)) {
-		kblog_put('t', to_host.tail);
+	if (queue_space(&to_host) >= len) {
+		kblog_put('t', to_host.state->tail);
 		queue_add_units(&to_host, bytes, len);
 	}
 	mutex_unlock(&to_host_mutex);
@@ -433,7 +428,7 @@ static void reset_rate_and_delay(void)
 void keyboard_clear_buffer(void)
 {
 	mutex_lock(&to_host_mutex);
-	queue_reset(&to_host);
+	queue_init(&to_host);
 	mutex_unlock(&to_host_mutex);
 	lpc_keyboard_clear_buffer();
 }
@@ -962,7 +957,7 @@ void keyboard_protocol_task(void)
 			}
 
 			/* Get a char from buffer. */
-			kblog_put('k', to_host.head);
+			kblog_put('k', to_host.state->head);
 			queue_remove_unit(&to_host, &chr);
 			kblog_put('K', chr);
 
@@ -1186,17 +1181,24 @@ static int command_8042_internal(int argc, char **argv)
 	ccprintf("controller_ram_address=0x%02x\n", controller_ram_address);
 	ccprintf("A20_status=%d\n", A20_status);
 
-	ccprintf("from_host.buf[]={");
-	for (i = from_host.head; i != from_host.tail;
-			i = (i + 1) % from_host.buf_bytes)
-		ccprintf("0x%02x, ", from_host.buf[i]);
+	ccprintf("from_host[]={");
+	for (i = 0; i < queue_count(&from_host); ++i) {
+		struct host_byte entry;
+
+		queue_peek_units(&from_host, &entry, i, 1);
+
+		ccprintf("0x%02x, 0x%02x, ", entry.type, entry.byte);
+	}
 	ccprintf("}\n");
 
-	ccprintf("to_host.buf[]={");
-	for (i = to_host.head;
-			i != to_host.tail;
-			i = (i + 1) % to_host.buf_bytes)
-		ccprintf("0x%02x, ", to_host.buf[i]);
+	ccprintf("to_host[]={");
+	for (i = 0; i < queue_count(&to_host); ++i) {
+		uint8_t entry;
+
+		queue_peek_units(&to_host, &entry, i, 1);
+
+		ccprintf("0x%02x, ", entry);
+	}
 	ccprintf("}\n");
 
 	return EC_SUCCESS;