fsi/gpio: Include command build in locked section

For implementing relative addressing mode, we'll need to build a command
that is coherent with CFAM state. To do that, include the
build_command_* functions in the locked section of read/write/term.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>

drivers/fsi/fsi-master-gpio.c

@@ -463,14 +463,10 @@ static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave,
 {
 	int rc;
 
-	mutex_lock(&master->cmd_lock);
-
 	rc = send_request(master, cmd);
 	if (!rc)
 		rc = poll_for_response(master, slave, resp_len, resp);
 
-	mutex_unlock(&master->cmd_lock);
-
 	return rc;
 }
 
@@ -479,12 +475,17 @@ static int fsi_master_gpio_read(struct fsi_master *_master, int link,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
+	mutex_lock(&master->cmd_lock);
 	build_abs_ar_command(&cmd, id, addr, size, NULL);
-	return fsi_master_gpio_xfer(master, id, &cmd, size, val);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, size, val);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_write(struct fsi_master *_master, int link,
@@ -492,12 +493,17 @@ static int fsi_master_gpio_write(struct fsi_master *_master, int link,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
+	mutex_lock(&master->cmd_lock);
 	build_abs_ar_command(&cmd, id, addr, size, val);
-	return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_term(struct fsi_master *_master,
@@ -505,12 +511,17 @@ static int fsi_master_gpio_term(struct fsi_master *_master,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
+	mutex_lock(&master->cmd_lock);
 	build_term_command(&cmd, id);
-	return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_break(struct fsi_master *_master, int link)