diff options
| author | Julian Wiedmann <jwi@linux.vnet.ibm.com> | 2017-03-23 14:55:08 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-25 14:23:40 +0100 |
| commit | 118b0404d68d4019ff7906175b3b85fb50f06e84 (patch) | |
| tree | 50f6dbe5a0765447f44e6140a63e1bab62d075f0 /drivers/s390/net/qeth_core_main.c | |
| parent | 60d59823046a7cfbfb6fe13ed9d320aafe1338a2 (diff) | |
s390/qeth: size calculation outbound buffers
[ Upstream commit 7d969d2e8890f546c8cec634b3aa5f57d4eef883 ]
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 <jwi@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390/net/qeth_core_main.c')
| -rw-r--r-- | drivers/s390/net/qeth_core_main.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index b5fa6bb56b29..838ed6213118 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -3842,6 +3842,7 @@ 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 @@ -3849,10 +3850,10 @@ 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); |