iwmc3200wifi: Avoid an offset calculation for each management frame.

Determine the offset at compile time.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 13 deletions

diff --git a/drivers/net/wireless/iwmc3200wifi/rx.c b/drivers/net/wireless/iwmc3200wifi/rx.c
index 6bd253ac533f..0619d6a1103c 100644
--- a/drivers/net/wireless/iwmc3200wifi/rx.c
+++ b/drivers/net/wireless/iwmc3200wifi/rx.c
@@ -868,36 +868,35 @@ static int iwm_mlme_mgt_frame(struct iwm_priv *iwm, u8 *buf,
         struct iwm_umac_notif_mgt_frame *mgt_frame =
                         (struct iwm_umac_notif_mgt_frame *)buf;
         struct ieee80211_mgmt *mgt = (struct ieee80211_mgmt *)mgt_frame->frame;
-        u8 *ie;
 
         IWM_HEXDUMP(iwm, DBG, MLME, "MGT: ", mgt_frame->frame,
                     le16_to_cpu(mgt_frame->len));
 
         if (ieee80211_is_assoc_req(mgt->frame_control)) {
-                ie = mgt->u.assoc_req.variable;;
-                iwm->req_ie_len =
-                                le16_to_cpu(mgt_frame->len) - (ie - (u8 *)mgt);
+                iwm->req_ie_len = le16_to_cpu(mgt_frame->len)
+                                  - offsetof(struct ieee80211_mgmt,
+                                             u.assoc_req.variable);
                 kfree(iwm->req_ie);
                 iwm->req_ie = kmemdup(mgt->u.assoc_req.variable,
                                       iwm->req_ie_len, GFP_KERNEL);
         } else if (ieee80211_is_reassoc_req(mgt->frame_control)) {
-                ie = mgt->u.reassoc_req.variable;;
-                iwm->req_ie_len =
-                                le16_to_cpu(mgt_frame->len) - (ie - (u8 *)mgt);
+                iwm->req_ie_len = le16_to_cpu(mgt_frame->len)
+                                  - offsetof(struct ieee80211_mgmt,
+                                             u.reassoc_req.variable);
                 kfree(iwm->req_ie);
                 iwm->req_ie = kmemdup(mgt->u.reassoc_req.variable,
                                       iwm->req_ie_len, GFP_KERNEL);
         } else if (ieee80211_is_assoc_resp(mgt->frame_control)) {
-                ie = mgt->u.assoc_resp.variable;;
-                iwm->resp_ie_len =
-                                le16_to_cpu(mgt_frame->len) - (ie - (u8 *)mgt);
+                iwm->resp_ie_len = le16_to_cpu(mgt_frame->len)
+                                   - offsetof(struct ieee80211_mgmt,
+                                              u.assoc_resp.variable);
                 kfree(iwm->resp_ie);
                 iwm->resp_ie = kmemdup(mgt->u.assoc_resp.variable,
                                        iwm->resp_ie_len, GFP_KERNEL);
         } else if (ieee80211_is_reassoc_resp(mgt->frame_control)) {
-                ie = mgt->u.reassoc_resp.variable;;
-                iwm->resp_ie_len =
-                                le16_to_cpu(mgt_frame->len) - (ie - (u8 *)mgt);
+                iwm->resp_ie_len = le16_to_cpu(mgt_frame->len)
+                                   - offsetof(struct ieee80211_mgmt,
+                                              u.reassoc_resp.variable);
                 kfree(iwm->resp_ie);
                 iwm->resp_ie = kmemdup(mgt->u.reassoc_resp.variable,
                                        iwm->resp_ie_len, GFP_KERNEL);