zephyr: change host console shim interface

Allow passing a whole string to the console buffer, which is sent to
host.

This should speed up printing because a mutex doesn't have to be locked
for every char separately.

BUG=b:191724484
BRANCH=none
TEST=Make sure buffering of console to host works with the
'ectool console' command

Signed-off-by: Dawid Niedzwiecki <dn@semihalf.com>
Change-Id: I5b081984bfa4f930ad4729b19975b1c2eb4bbd18
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2988193
Reviewed-by: Keith Short <keithshort@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

3 files changed, 26 insertions, 19 deletions

diff --git a/zephyr/shim/include/zephyr_console_shim.h b/zephyr/shim/include/zephyr_console_shim.h
index 03e2d115c6..df9f189c9a 100644
--- a/zephyr/shim/include/zephyr_console_shim.h
+++ b/zephyr/shim/include/zephyr_console_shim.h
@@ -56,11 +56,12 @@ int zshim_run_ec_console_command(int (*handler)(int argc, char **argv),
 	_ZEPHYR_SHELL_COMMAND_SHIM(NAME, ROUTINE, ARGDESC, HELP)
 
 /**
- * console_buf_notify_char() - Notify the console host command buffer
- * of a new character on the console.
+ * console_buf_notify_chars() - Notify the console host command buffer
+ * of bytes on the console.
  *
- * @c:			The character that appeared on the console.
+ * @s:			The pointer to the string.
+ * @len:		The size of the string.
  */
-void console_buf_notify_char(char c);
+void console_buf_notify_chars(const char *s, size_t len);
 
 #endif  /* __CROS_EC_ZEPHYR_CONSOLE_SHIM_H */
diff --git a/zephyr/shim/src/console.c b/zephyr/shim/src/console.c
index 5d4e2de16f..28f0067249 100644
--- a/zephyr/shim/src/console.c
+++ b/zephyr/shim/src/console.c
@@ -220,7 +220,7 @@ void uart_write_char(char c)
 	printk("%c", c);
 
 	if (IS_ENABLED(CONFIG_PLATFORM_EC_HOSTCMD_CONSOLE))
-		console_buf_notify_char(c);
+		console_buf_notify_chars(&c, 1);
 }
 
 void uart_flush_output(void)
diff --git a/zephyr/shim/src/console_buffer.c b/zephyr/shim/src/console_buffer.c
index aa3a2300e6..427ae47768 100644
--- a/zephyr/shim/src/console_buffer.c
+++ b/zephyr/shim/src/console_buffer.c
@@ -22,31 +22,37 @@ static inline uint32_t next_idx(uint32_t cur_idx)
 
 K_MUTEX_DEFINE(console_write_lock);
 
-void console_buf_notify_char(char c)
+void console_buf_notify_chars(const char *s, size_t len)
 {
-	/* Don't copy null byte into buffer */
-	if (!c)
-		return;
-
 	/*
-	 * This is just notifying of a console character for debugging
+	 * This is just notifying of console characters for debugging
 	 * output, so if we are unable to lock the mutex immediately,
-	 * then just drop the character.
+	 * then just drop the string.
 	 */
-	if (!k_mutex_lock(&console_write_lock, K_NO_WAIT)) {
-		/* We got the mutex. */
+	if (k_mutex_lock(&console_write_lock, K_NO_WAIT))
+		return;
+	/* We got the mutex. */
+	while (len--) {
+		/* Don't copy null byte into buffer */
+		if (!(*s))
+			continue;
+
 		uint32_t new_tail = next_idx(tail_idx);
 
-		/* Check if we are starting to overwrite our snapshot heads */
+		/* Check if we are starting to overwrite our snapshot
+		 * heads
+		 */
 		if (new_tail == previous_snapshot_idx)
-			previous_snapshot_idx = next_idx(previous_snapshot_idx);
+			previous_snapshot_idx =
+				next_idx(previous_snapshot_idx);
 		if (new_tail == current_snapshot_idx)
-			current_snapshot_idx = next_idx(current_snapshot_idx);
+			current_snapshot_idx =
+				next_idx(current_snapshot_idx);
 
-		console_buf[new_tail] = c;
+		console_buf[new_tail] = *s++;
 		tail_idx = new_tail;
-		k_mutex_unlock(&console_write_lock);
 	}
+	k_mutex_unlock(&console_write_lock);
 }
 
 enum ec_status uart_console_read_buffer_init(void)