[PATCH 2/4] tty: amiserial: replace get_zeroed_page() with kzalloc()

["Mike Rapoport (Microsoft)" <rppt@kernel.org>]

rs_startup() allocates a transmit ring buffer that is used to buffer reads
and writes from/to serial data register.

This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 drivers/tty/amiserial.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 81eaca751541..28af0fd98181 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -443,23 +443,23 @@ static int rs_startup(struct tty_struct *tty, struct serial_state *info)
 	struct tty_port *port = &info->tport;
 	unsigned long flags;
 	int	retval=0;
-	unsigned long page;
+	void *buffer;
 
-	page = get_zeroed_page(GFP_KERNEL);
-	if (!page)
+	buffer = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!buffer)
 		return -ENOMEM;
 
 	local_irq_save(flags);
 
 	if (tty_port_initialized(port)) {
-		free_page(page);
+		kfree(buffer);
 		goto errout;
 	}
 
 	if (info->xmit.buf)
-		free_page(page);
+		kfree(buffer);
 	else
-		info->xmit.buf = (unsigned char *) page;
+		info->xmit.buf = buffer;
 
 #ifdef SERIAL_DEBUG_OPEN
 	printk("starting up ttys%d ...", info->line);
@@ -537,7 +537,7 @@ static void rs_shutdown(struct tty_struct *tty, struct serial_state *info)
 	 */
 	free_irq(IRQ_AMIGA_VERTB, info);
 
-	free_page((unsigned long)info->xmit.buf);
+	kfree(info->xmit.buf);
 	info->xmit.buf = NULL;
 
 	info->IER = 0;

-- 
2.53.0