s390/qeth: indicate contiguous TX buffer elements (a875fd16) · Commits · 戴 / test

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 <jwi@linux.ibm.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core_main.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -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++;
		}

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