Input: ili210x - use kvmalloc() to allocate buffer for firmware update

Allocating a contiguous buffer of 64K may fail if memory is sufficiently
fragmented, and may cause OOM kill of an unrelated process. However we
do not need to have contiguous memory. We also do not need to zero
out the buffer since it will be overwritten with firmware data.

Switch to using kvmalloc() instead of kzalloc().

Link: https://lore.kernel.org/r/20240609234757.610273-1-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: dtor

drivers/input/touchscreen/ili210x.c

@@ -597,7 +597,7 @@ static int ili251x_firmware_to_buffer(const struct firmware *fw,
 	 * once, copy them all into this buffer at the right locations, and then
 	 * do all operations on this linear buffer.
 	 */
-	fw_buf = kzalloc(SZ_64K, GFP_KERNEL);
+	fw_buf = kvmalloc(SZ_64K, GFP_KERNEL);
 	if (!fw_buf)
 		return -ENOMEM;
 
@@ -627,7 +627,7 @@ static int ili251x_firmware_to_buffer(const struct firmware *fw,
 	return 0;
 
 err_big:
-	kfree(fw_buf);
+	kvfree(fw_buf);
 	return error;
 }
 
@@ -870,7 +870,7 @@ static ssize_t ili210x_firmware_update_store(struct device *dev,
 	ili210x_hardware_reset(priv->reset_gpio);
 	dev_dbg(dev, "Firmware update ended, error=%i\n", error);
 	enable_irq(client->irq);
-	kfree(fwbuf);
+	kvfree(fwbuf);
 	return error;
 }