From: Julian Wiedmann Date: Wed, 6 May 2020 08:09:46 +0000 (+0200) Subject: s390/qeth: indicate contiguous TX buffer elements X-Git-Tag: v5.8-rc1~165^2~292^2~3 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a875fd1620ffb65f4e0d488f7fe1fba62cf9fedd;p=linux-2.6-block.git s390/qeth: indicate contiguous TX buffer elements The TX path usually maps the full content of a page into a buffer element. But there's specific skb layouts (ie. linearized TSO skbs) where the HW header (1) requires a separate buffer element, and (2) is page-contiguous with the packet data that's mapped into the next buffer element. Flag such buffer elements accordingly, so that HW can optimize its data access for them. Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller --- diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 9c9a6edb5384..4d1d053eebb7 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -4110,8 +4110,16 @@ static unsigned int qeth_fill_buffer(struct qeth_qdio_out_buffer *buf, buffer->element[element].addr = virt_to_phys(hdr); buffer->element[element].length = hd_len; buffer->element[element].eflags = SBAL_EFLAGS_FIRST_FRAG; - /* remember to free cache-allocated HW header: */ - buf->is_header[element] = ((void *)hdr != skb->data); + + /* HW header is allocated from cache: */ + if ((void *)hdr != skb->data) + buf->is_header[element] = 1; + /* HW header was pushed and is contiguous with linear part: */ + else if (length > 0 && !PAGE_ALIGNED(data) && + (data == (char *)hdr + hd_len)) + buffer->element[element].eflags |= + SBAL_EFLAGS_CONTIGUOUS; + element++; }