[PATCH 3/4] tty: serial: men_z135_uart: replace __get_free_page() with kmalloc()

[Mike Rapoport (Microsoft)]

men_z135_probe() allocates a receive staging buffer filled by the
CPU via memcpy_fromio() from the device MMIO region.

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_free_page() with kmalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 drivers/tty/serial/men_z135_uart.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c
index 6fad57fee912..9c32b01edc9e 100644
--- a/drivers/tty/serial/men_z135_uart.c
+++ b/drivers/tty/serial/men_z135_uart.c
@@ -17,6 +17,7 @@
 #include <linux/bitops.h>
 #include <linux/mcb.h>
 
+#include <linux/slab.h>
 #define MEN_Z135_MAX_PORTS		12
 #define MEN_Z135_BASECLK		29491200
 #define MEN_Z135_FIFO_SIZE		1024
@@ -811,7 +812,7 @@ static int men_z135_probe(struct mcb_device *mdev,
 	if (!uart)
 		return -ENOMEM;
 
-	uart->rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
+	uart->rxbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!uart->rxbuf)
 		return -ENOMEM;
 
@@ -841,7 +842,7 @@ static int men_z135_probe(struct mcb_device *mdev,
 	return 0;
 
 err:
-	free_page((unsigned long) uart->rxbuf);
+	kfree(uart->rxbuf);
 	dev_err(dev, "Failed to add UART: %d\n", err);
 
 	return err;
@@ -858,7 +859,7 @@ static void men_z135_remove(struct mcb_device *mdev)
 
 	line--;
 	uart_remove_one_port(&men_z135_driver, &uart->port);
-	free_page((unsigned long) uart->rxbuf);
+	kfree(uart->rxbuf);
 }
 
 static const struct mcb_device_id men_z135_ids[] = {

-- 
2.53.0