From ce320f44d677549a29ae8d6ae79e66d1c997f87a Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 12 Feb 2014 18:58:34 +0000 Subject: [PATCH] sfc: Cache skb->data in local variable in efx_ptp_rx() Signed-off-by: Ben Hutchings Signed-off-by: Shradha Shah Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ptp.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c index 52be63dc68cf..7d0de5002f41 100644 --- a/drivers/net/ethernet/sfc/ptp.c +++ b/drivers/net/ethernet/sfc/ptp.c @@ -1366,6 +1366,7 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb) struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb; u8 *match_data_012, *match_data_345; unsigned int version; + u8 *data; match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS); @@ -1374,7 +1375,8 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb) if (!pskb_may_pull(skb, PTP_V1_MIN_LENGTH)) { return false; } - version = ntohs(*(__be16 *)&skb->data[PTP_V1_VERSION_OFFSET]); + data = skb->data; + version = ntohs(*(__be16 *)&data[PTP_V1_VERSION_OFFSET]); if (version != PTP_VERSION_V1) { return false; } @@ -1382,13 +1384,14 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb) /* PTP V1 uses all six bytes of the UUID to match the packet * to the timestamp */ - match_data_012 = skb->data + PTP_V1_UUID_OFFSET; - match_data_345 = skb->data + PTP_V1_UUID_OFFSET + 3; + match_data_012 = data + PTP_V1_UUID_OFFSET; + match_data_345 = data + PTP_V1_UUID_OFFSET + 3; } else { if (!pskb_may_pull(skb, PTP_V2_MIN_LENGTH)) { return false; } - version = skb->data[PTP_V2_VERSION_OFFSET]; + data = skb->data; + version = data[PTP_V2_VERSION_OFFSET]; if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) { return false; } @@ -1400,17 +1403,17 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb) * enhanced mode fixes this issue and uses bytes 0-2 * and byte 5-7 of the UUID. */ - match_data_345 = skb->data + PTP_V2_UUID_OFFSET + 5; + match_data_345 = data + PTP_V2_UUID_OFFSET + 5; if (ptp->mode == MC_CMD_PTP_MODE_V2) { - match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 2; + match_data_012 = data + PTP_V2_UUID_OFFSET + 2; } else { - match_data_012 = skb->data + PTP_V2_UUID_OFFSET + 0; + match_data_012 = data + PTP_V2_UUID_OFFSET + 0; BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2_ENHANCED); } } /* Does this packet require timestamping? */ - if (ntohs(*(__be16 *)&skb->data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) { + if (ntohs(*(__be16 *)&data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) { match->state = PTP_PACKET_STATE_UNMATCHED; /* We expect the sequence number to be in the same position in @@ -1426,8 +1429,8 @@ static bool efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb) (match_data_345[0] << 24)); match->words[1] = (match_data_345[1] | (match_data_345[2] << 8) | - (skb->data[PTP_V1_SEQUENCE_OFFSET + - PTP_V1_SEQUENCE_LENGTH - 1] << + (data[PTP_V1_SEQUENCE_OFFSET + + PTP_V1_SEQUENCE_LENGTH - 1] << 16)); } else { match->state = PTP_PACKET_STATE_MATCH_UNWANTED; -- GitLab