[PATCH] NFC: port100: Introduce the use of function put_unaligned_le16

From: Vaishali Thakkar
Date: Wed Dec 24 2014 - 08:12:46 EST


This patch introduces the use of function put_unaligned_le16.

This is done using Coccinelle and semantic patch used is as follows:

@a@
typedef u16, __le16;
{u16,__le16} e16;
identifier tmp;
expression ptr;
expression y,e;
type T;
@@

- tmp = cpu_to_le16(y);

<+... when != tmp
(
- memcpy(ptr, (T)&tmp, \(2\|sizeof(u16)\|sizeof(__le16)\|sizeof(e16)\));
+ put_unaligned_le16(y,ptr);
|
- memcpy(ptr, (T)&tmp, ...);
+ put_unaligned_le16(y,ptr);
)
...+>
? tmp = e

@@ type T; identifier a.tmp; @@

- T tmp;
...when != tmp

Signed-off-by: Vaishali Thakkar <vthakkar1994@xxxxxxxxx>
---
Changes since v1:
<asm/unaligned.h> has arch-specific knowlege of which of
the implementations needs to be used. So, include it instaed
of <linux/unaligned/access_ok.h>.
Changes since v2:
Fix typing mistake in subject

drivers/nfc/port100.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/nfc/port100.c b/drivers/nfc/port100.c
index 4ac4d31..440f0f3 100644
--- a/drivers/nfc/port100.c
+++ b/drivers/nfc/port100.c
@@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/usb.h>
#include <net/nfc/digital.h>
+#include <asm/unaligned.h>

#define VERSION "0.1"

@@ -1136,7 +1137,6 @@ static int port100_in_send_cmd(struct nfc_digital_dev *ddev,
{
struct port100 *dev = nfc_digital_get_drvdata(ddev);
struct port100_cb_arg *cb_arg;
- __le16 timeout;

cb_arg = kzalloc(sizeof(struct port100_cb_arg), GFP_KERNEL);
if (!cb_arg)
@@ -1145,9 +1145,7 @@ static int port100_in_send_cmd(struct nfc_digital_dev *ddev,
cb_arg->complete_cb = cb;
cb_arg->complete_arg = arg;

- timeout = cpu_to_le16(_timeout * 10);
-
- memcpy(skb_push(skb, sizeof(__le16)), &timeout, sizeof(__le16));
+ put_unaligned_le16(_timeout * 10, skb_push(skb, sizeof(__le16)));

return port100_send_cmd_async(dev, PORT100_CMD_IN_COMM_RF, skb,
port100_in_comm_rf_complete, cb_arg);
--
1.9.1

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