[PATCH net-next 3/8] ice: use kzalloc() to allocate staging buffer for reading from GNSS

[Mike Rapoport (Microsoft)]

ice_gnss_read() uses get_zeroed_page() to  allocate a staging buffer for
reading GNSS module data via I2C bus.

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.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

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 at kernel.org>
---
 drivers/net/ethernet/intel/ice/ice_gnss.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
index 8fd954f1ebd6..7d21c3417b0b 100644
--- a/drivers/net/ethernet/intel/ice/ice_gnss.c
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
@@ -2,6 +2,7 @@
 /* Copyright (C) 2021-2022, Intel Corporation. */
 
 #include "ice.h"
+#include <linux/slab.h>
 #include "ice_lib.h"
 
 /**
@@ -124,7 +125,7 @@ static void ice_gnss_read(struct kthread_work *work)
 
 	data_len = min_t(typeof(data_len), data_len, PAGE_SIZE);
 
-	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf) {
 		err = -ENOMEM;
 		goto requeue;
@@ -151,7 +152,7 @@ static void ice_gnss_read(struct kthread_work *work)
 			 count, i);
 	delay = ICE_GNSS_TIMER_DELAY_TIME;
 free_buf:
-	free_page((unsigned long)buf);
+	kfree(buf);
 requeue:
 	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, delay);
 	if (err)

-- 
2.53.0