The size of struct th_header is 8 byte and the size of struct th_sweep
is 16 byte. The memory for is allocated, initialized, used and
deallocated a few lines later.
It is more efficient to avoid the allocation/free dance and keeping the
variable on stack. Especially since the compiler is smart enough to not
allocate the memory on stack but assign the values directly.
Declare struct th_sweep/th_header on stack and initialize it to zero.
Use the local variable instead of the pointer.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/s390/net/ctcm_fsms.c | 17 +++++-----------
drivers/s390/net/ctcm_main.c | 39 ++++++++----------------------------
drivers/s390/net/ctcm_mpc.c | 21 ++++---------------
3 files changed, 17 insertions(+), 60 deletions(-)
diff --git a/drivers/s390/net/ctcm_fsms.c b/drivers/s390/net/ctcm_fsms.c
index 661d2a49bce96..d6592d576d1dd 100644
--- a/drivers/s390/net/ctcm_fsms.c
+++ b/drivers/s390/net/ctcm_fsms.c
@@ -1220,7 +1220,7 @@ static void ctcmpc_chx_txdone(fsm_instance *fi, int event, void *arg)
unsigned long duration;
struct sk_buff *peekskb;
int rc;
- struct th_header *header;
+ struct th_header header = {0, };
struct pdu *p_header;
unsigned long done_stamp = jiffies;
@@ -1303,24 +1303,17 @@ static void ctcmpc_chx_txdone(fsm_instance *fi, int event, void *arg)
/* p_header points to the last one we handled */
if (p_header)
p_header->pdu_flag |= PDU_LAST; /*Say it's the last one*/
- header = kzalloc(TH_HEADER_LENGTH, gfp_type());
- if (!header) {
- spin_unlock(&ch->collect_lock);
- fsm_event(priv->mpcg->fsm, MPCG_EVENT_INOP, dev);
- goto done;
- }
- header->th_ch_flag = TH_HAS_PDU; /* Normal data */
+
+ header.th_ch_flag = TH_HAS_PDU; /* Normal data */
ch->th_seq_num++;
- header->th_seq_num = ch->th_seq_num;
+ header.th_seq_num = ch->th_seq_num;
CTCM_PR_DBGDATA("%s: ToVTAM_th_seq= %08x\n" ,
__func__, ch->th_seq_num);
- memcpy(skb_push(ch->trans_skb, TH_HEADER_LENGTH), header,
+ memcpy(skb_push(ch->trans_skb, TH_HEADER_LENGTH), &header,
TH_HEADER_LENGTH); /* put the TH on the packet */
- kfree(header);
-
CTCM_PR_DBGDATA("%s: trans_skb len:%04x \n",
__func__, ch->trans_skb->len);
CTCM_PR_DBGDATA("%s: up-to-50 bytes of trans_skb "
diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c
index d06809eac16d3..6c7d6bbd27406 100644
--- a/drivers/s390/net/ctcm_main.c
+++ b/drivers/s390/net/ctcm_main.c
@@ -599,7 +599,7 @@ static void ctcmpc_send_sweep_req(struct channel *rch)
struct net_device *dev = rch->netdev;
struct ctcm_priv *priv;
struct mpc_group *grp;
- struct th_sweep *header;
+ struct th_sweep header = { 0, };
struct sk_buff *sweep_skb;
struct channel *ch;
/* int rc = 0; */
@@ -623,24 +623,10 @@ static void ctcmpc_send_sweep_req(struct channel *rch)
goto nomem;
}
- header = kmalloc(TH_SWEEP_LENGTH, gfp_type());
+ header.th.th_ch_flag = TH_SWEEP_REQ; /* 0x0f */
+ header.sw.th_last_seq = ch->th_seq_num;
- if (!header) {
- dev_kfree_skb_any(sweep_skb);
- /* rc = -ENOMEM; */
- goto nomem;
- }
-
- header->th.th_seg = 0x00 ;
- header->th.th_ch_flag = TH_SWEEP_REQ; /* 0x0f */
- header->th.th_blk_flag = 0x00;
- header->th.th_is_xid = 0x00;
- header->th.th_seq_num = 0x00;
- header->sw.th_last_seq = ch->th_seq_num;
-
- skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH);
-
- kfree(header);
+ skb_put_data(sweep_skb, &header, TH_SWEEP_LENGTH);
netif_trans_update(dev);
skb_queue_tail(&ch->sweep_queue, sweep_skb);
@@ -666,7 +652,7 @@ static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
struct net_device *dev = ch->netdev;
struct ctcm_priv *priv = dev->ml_priv;
struct mpc_group *grp = priv->mpcg;
- struct th_header *header;
+ struct th_header header = { 0, };
struct sk_buff *nskb;
int rc = 0;
int ccw_idx;
@@ -768,24 +754,15 @@ static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb)
ch->prof.txlen += skb->len - PDU_HEADER_LENGTH;
- header = kmalloc(TH_HEADER_LENGTH, gfp_type());
- if (!header)
- goto nomem_exit;
-
- header->th_seg = 0x00;
- header->th_ch_flag = TH_HAS_PDU; /* Normal data */
- header->th_blk_flag = 0x00;
- header->th_is_xid = 0x00; /* Just data here */
+ header.th_ch_flag = TH_HAS_PDU; /* Normal data */
ch->th_seq_num++;
- header->th_seq_num = ch->th_seq_num;
+ header.th_seq_num = ch->th_seq_num;
CTCM_PR_DBGDATA("%s(%s) ToVTAM_th_seq= %08x\n" ,
__func__, dev->name, ch->th_seq_num);
/* put the TH on the packet */
- memcpy(skb_push(skb, TH_HEADER_LENGTH), header, TH_HEADER_LENGTH);
-
- kfree(header);
+ memcpy(skb_push(skb, TH_HEADER_LENGTH), &header, TH_HEADER_LENGTH);
CTCM_PR_DBGDATA("%s(%s): skb len: %04x\n - pdu header and data for "
"up to 32 bytes sent to vtam:\n",
diff --git a/drivers/s390/net/ctcm_mpc.c b/drivers/s390/net/ctcm_mpc.c
index 85a1a4533cbeb..04a51cc89e74c 100644
--- a/drivers/s390/net/ctcm_mpc.c
+++ b/drivers/s390/net/ctcm_mpc.c
@@ -641,7 +641,7 @@ static void ctcmpc_send_sweep_resp(struct channel *rch)
struct net_device *dev = rch->netdev;
struct ctcm_priv *priv = dev->ml_priv;
struct mpc_group *grp = priv->mpcg;
- struct th_sweep *header;
+ struct th_sweep header = { 0, };
struct sk_buff *sweep_skb;
struct channel *ch = priv->channel[CTCM_WRITE];
@@ -655,23 +655,10 @@ static void ctcmpc_send_sweep_resp(struct channel *rch)
goto done;
}
- header = kmalloc(sizeof(struct th_sweep), gfp_type());
+ header.th.th_ch_flag = TH_SWEEP_RESP;
+ header.sw.th_last_seq = ch->th_seq_num;
- if (!header) {
- dev_kfree_skb_any(sweep_skb);
- goto done;
- }
-
- header->th.th_seg = 0x00 ;
- header->th.th_ch_flag = TH_SWEEP_RESP;
- header->th.th_blk_flag = 0x00;
- header->th.th_is_xid = 0x00;
- header->th.th_seq_num = 0x00;
- header->sw.th_last_seq = ch->th_seq_num;
-
- skb_put_data(sweep_skb, header, TH_SWEEP_LENGTH);
-
- kfree(header);
+ skb_put_data(sweep_skb, &header, TH_SWEEP_LENGTH);
netif_trans_update(dev);
skb_queue_tail(&ch->sweep_queue, sweep_skb);
--
2.29.2
