From 7d969d2e8890f546c8cec634b3aa5f57d4eef883 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Thu, 23 Mar 2017 14:55:08 +0100 Subject: s390/qeth: size calculation outbound buffers Depending on the device type, hard_start_xmit() builds different output buffer formats. For instance with HiperSockets, on both L2 and L3 we strip the ETH header from the skb - L3 doesn't need it, and L2 carries it in the buffer's header element. For this, we pass data_offset = ETH_HLEN all the way down to __qeth_fill_buffer(), where skb->data is then adjusted accordingly. But the initial size calculation still considers the *full* skb length (including the ETH header). So qeth_get_elements_no() can erroneously reject a skb as too big, even though it would actually fit into an output buffer once the ETH header has been trimmed off later. Fix this by passing an additional offset to qeth_get_elements_no(), that indicates where in the skb the on-wire data actually begins. Since the current code uses data_offset=-1 for some special handling on OSA, we need to clamp data_offset to 0... On HiperSockets this helps when sending ~MTU-size skbs with weird page alignment. No change for OSA or AF_IUCV. Signed-off-by: Julian Wiedmann Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- drivers/s390/net/qeth_core.h | 3 ++- drivers/s390/net/qeth_core_main.c | 5 +++-- drivers/s390/net/qeth_l2_main.c | 5 +++-- drivers/s390/net/qeth_l3_main.c | 5 +++-- 4 files changed, 11 insertions(+), 7 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index e7addea8741b..d9561e39c3b2 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -961,7 +961,8 @@ int qeth_bridgeport_query_ports(struct qeth_card *card, int qeth_bridgeport_setrole(struct qeth_card *card, enum qeth_sbp_roles role); int qeth_bridgeport_an_set(struct qeth_card *card, int enable); int qeth_get_priority_queue(struct qeth_card *, struct sk_buff *, int, int); -int qeth_get_elements_no(struct qeth_card *, struct sk_buff *, int); +int qeth_get_elements_no(struct qeth_card *card, struct sk_buff *skb, + int extra_elems, int data_offset); int qeth_get_elements_for_frags(struct sk_buff *); int qeth_do_send_packet_fast(struct qeth_card *, struct qeth_qdio_out_q *, struct sk_buff *, struct qeth_hdr *, int, int, int); diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 315d8a2db7c0..9a5f99ccb122 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -3837,6 +3837,7 @@ EXPORT_SYMBOL_GPL(qeth_get_elements_for_frags); * @card: qeth card structure, to check max. elems. * @skb: SKB address * @extra_elems: extra elems needed, to check against max. + * @data_offset: range starts at skb->data + data_offset * * Returns the number of pages, and thus QDIO buffer elements, needed to cover * skb data, including linear part and fragments. Checks if the result plus @@ -3844,10 +3845,10 @@ EXPORT_SYMBOL_GPL(qeth_get_elements_for_frags); * Note: extra_elems is not included in the returned result. */ int qeth_get_elements_no(struct qeth_card *card, - struct sk_buff *skb, int extra_elems) + struct sk_buff *skb, int extra_elems, int data_offset) { int elements = qeth_get_elements_for_range( - (addr_t)skb->data, + (addr_t)skb->data + data_offset, (addr_t)skb->data + skb_headlen(skb)) + qeth_get_elements_for_frags(skb); diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index bea483307618..af4e6a639fec 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -849,7 +849,7 @@ static int qeth_l2_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) * chaining we can not send long frag lists */ if ((card->info.type != QETH_CARD_TYPE_IQD) && - !qeth_get_elements_no(card, new_skb, 0)) { + !qeth_get_elements_no(card, new_skb, 0, 0)) { int lin_rc = skb_linearize(new_skb); if (card->options.performance_stats) { @@ -894,7 +894,8 @@ static int qeth_l2_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) } } - elements = qeth_get_elements_no(card, new_skb, elements_needed); + elements = qeth_get_elements_no(card, new_skb, elements_needed, + (data_offset > 0) ? data_offset : 0); if (!elements) { if (data_offset >= 0) kmem_cache_free(qeth_core_header_cache, hdr); diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 06d0addcc058..72aa9537a725 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -2867,7 +2867,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) */ if ((card->info.type != QETH_CARD_TYPE_IQD) && ((use_tso && !qeth_l3_get_elements_no_tso(card, new_skb, 1)) || - (!use_tso && !qeth_get_elements_no(card, new_skb, 0)))) { + (!use_tso && !qeth_get_elements_no(card, new_skb, 0, 0)))) { int lin_rc = skb_linearize(new_skb); if (card->options.performance_stats) { @@ -2909,7 +2909,8 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) elements = use_tso ? qeth_l3_get_elements_no_tso(card, new_skb, hdr_elements) : - qeth_get_elements_no(card, new_skb, hdr_elements); + qeth_get_elements_no(card, new_skb, hdr_elements, + (data_offset > 0) ? data_offset : 0); if (!elements) { if (data_offset >= 0) kmem_cache_free(qeth_core_header_cache, hdr); -- cgit v1.2.3 From acd9776b5c45ef02d1a210969a6fcc058afb76e3 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Thu, 23 Mar 2017 14:55:09 +0100 Subject: s390/qeth: no ETH header for outbound AF_IUCV With AF_IUCV traffic, the skb passed to hard_start_xmit() has a 14 byte slot at skb->data, intended for an ETH header. qeth_l3_fill_af_iucv_hdr() fills this ETH header... and then immediately moves it to the skb's headroom, where it disappears and is never seen again. But it's still possible for us to return NETDEV_TX_BUSY after the skb has been modified. Since we didn't get a private copy of the skb, the next time the skb is delivered to hard_start_xmit() it no longer has the expected layout (we moved the ETH header to the headroom, so skb->data now starts at the IUCV_TRANS header). So when qeth_l3_fill_af_iucv_hdr() does another round of rebuilding, the resulting qeth header ends up all wrong. On transmission, the buffer is then rejected by the HiperSockets device with SBALF15 = x'04'. When this error is passed back to af_iucv as TX_NOTIFY_UNREACHABLE, it tears down the offending socket. As the ETH header for AF_IUCV serves no purpose, just align the code to what we do for IP traffic on L3 HiperSockets: keep the ETH header at skb->data, and pass down data_offset = ETH_HLEN to qeth_fill_buffer(). When mapping the payload into the SBAL elements, the ETH header is then stripped off. This avoids the skb manipulations in qeth_l3_fill_af_iucv_hdr(), and any buffer re-entering hard_start_xmit() after NETDEV_TX_BUSY is now processed properly. Signed-off-by: Julian Wiedmann Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- drivers/s390/net/qeth_l3_main.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 72aa9537a725..653f0fb76573 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -2609,17 +2609,13 @@ static void qeth_l3_fill_af_iucv_hdr(struct qeth_card *card, char daddr[16]; struct af_iucv_trans_hdr *iucv_hdr; - skb_pull(skb, 14); - card->dev->header_ops->create(skb, card->dev, 0, - card->dev->dev_addr, card->dev->dev_addr, - card->dev->addr_len); - skb_pull(skb, 14); - iucv_hdr = (struct af_iucv_trans_hdr *)skb->data; memset(hdr, 0, sizeof(struct qeth_hdr)); hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3; hdr->hdr.l3.ext_flags = 0; - hdr->hdr.l3.length = skb->len; + hdr->hdr.l3.length = skb->len - ETH_HLEN; hdr->hdr.l3.flags = QETH_HDR_IPV6 | QETH_CAST_UNICAST; + + iucv_hdr = (struct af_iucv_trans_hdr *) (skb->data + ETH_HLEN); memset(daddr, 0, sizeof(daddr)); daddr[0] = 0xfe; daddr[1] = 0x80; @@ -2823,10 +2819,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) if ((card->info.type == QETH_CARD_TYPE_IQD) && !skb_is_nonlinear(skb)) { new_skb = skb; - if (new_skb->protocol == ETH_P_AF_IUCV) - data_offset = 0; - else - data_offset = ETH_HLEN; + data_offset = ETH_HLEN; hdr = kmem_cache_alloc(qeth_core_header_cache, GFP_ATOMIC); if (!hdr) goto tx_drop; -- cgit v1.2.3