[PATCH 3/4] USB: speedtch: replace __get_free_page() with kmalloc()

[Mike Rapoport (Microsoft)]

speedtch_upload_firmware() allocates a temporary buffer used to feed the
firmware to the device.

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

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
Assisted-by: copilot:claude-opus
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 drivers/usb/atm/speedtch.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/atm/speedtch.c b/drivers/usb/atm/speedtch.c
index 9d28c652bcd8..e5e021aafbd3 100644
--- a/drivers/usb/atm/speedtch.c
+++ b/drivers/usb/atm/speedtch.c
@@ -241,7 +241,7 @@ static int speedtch_upload_firmware(struct speedtch_instance_data *instance,
 
 	usb_dbg(usbatm, "%s entered\n", __func__);
 
-	buffer = (unsigned char *)__get_free_page(GFP_KERNEL);
+	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buffer) {
 		ret = -ENOMEM;
 		usb_dbg(usbatm, "%s: no memory for buffer!\n", __func__);
@@ -340,7 +340,7 @@ static int speedtch_upload_firmware(struct speedtch_instance_data *instance,
 	ret = 0;
 
 out_free:
-	free_page((unsigned long)buffer);
+	kfree(buffer);
 out:
 	return ret;
 }

-- 
2.53.0