freebsd-skq/sys/dev/mlx5/mlx5_ib/mlx5_ib_ah.c
Hans Petter Selasky 1456d97c01 Optimize ibcore RoCE address handle creation from user-space.
Creating a UD address handle from user-space or from the kernel-space,
when the link layer is ethernet, requires resolving the remote L3
address into a L2 address. Doing this from the kernel is easy because
the required ARP(IPv4) and ND6(IPv6) address resolving APIs are readily
available. In userspace such an interface does not exist and kernel
help is required.

It should be noted that in an IP-based GID environment, the GID itself
does not contain all the information needed to resolve the destination
IP address. For example information like VLAN ID and SCOPE ID, is not
part of the GID and must be fetched from the GID attributes. Therefore
a source GID should always be referred to as a GID index. Instead of
going through various racy steps to obtain information about the
GID attributes from user-space, this is now all done by the kernel.

This patch optimises the L3 to L2 address resolving using the existing
create address handle uverbs interface, retrieving back the L2 address
as an additional user-space information structure.

This commit combines the following Linux upstream commits:

IB/core: Let create_ah return extended response to user
IB/core: Change ib_resolve_eth_dmac to use it in create AH
IB/mlx5: Make create/destroy_ah available to userspace
IB/mlx5: Use kernel driver to help userspace create ah
IB/mlx5: Report that device has udata response in create_ah

MFC after:	1 week
Sponsored by:	Mellanox Technologies
2018-03-05 14:34:52 +00:00

131 lines
4.0 KiB
C

/*-
* Copyright (c) 2013-2015, Mellanox Technologies, Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include "mlx5_ib.h"
static struct ib_ah *create_ib_ah(struct mlx5_ib_dev *dev,
struct mlx5_ib_ah *ah,
struct ib_ah_attr *ah_attr,
enum rdma_link_layer ll)
{
if (ah_attr->ah_flags & IB_AH_GRH) {
memcpy(ah->av.rgid, &ah_attr->grh.dgid, 16);
ah->av.grh_gid_fl = cpu_to_be32(ah_attr->grh.flow_label |
(1 << 30) |
ah_attr->grh.sgid_index << 20);
ah->av.hop_limit = ah_attr->grh.hop_limit;
ah->av.tclass = ah_attr->grh.traffic_class;
}
ah->av.stat_rate_sl = (ah_attr->static_rate << 4);
if (ll == IB_LINK_LAYER_ETHERNET) {
memcpy(ah->av.rmac, ah_attr->dmac, sizeof(ah_attr->dmac));
ah->av.udp_sport =
mlx5_get_roce_udp_sport(dev,
ah_attr->port_num,
ah_attr->grh.sgid_index);
ah->av.stat_rate_sl |= (ah_attr->sl & 0x7) << 1;
} else {
ah->av.rlid = cpu_to_be16(ah_attr->dlid);
ah->av.fl_mlid = ah_attr->src_path_bits & 0x7f;
ah->av.stat_rate_sl |= (ah_attr->sl & 0xf);
}
return &ah->ibah;
}
struct ib_ah *mlx5_ib_create_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr,
struct ib_udata *udata)
{
struct mlx5_ib_ah *ah;
struct mlx5_ib_dev *dev = to_mdev(pd->device);
enum rdma_link_layer ll;
ll = pd->device->get_link_layer(pd->device, ah_attr->port_num);
if (ll == IB_LINK_LAYER_ETHERNET && !(ah_attr->ah_flags & IB_AH_GRH))
return ERR_PTR(-EINVAL);
if (ll == IB_LINK_LAYER_ETHERNET && udata) {
int err;
struct mlx5_ib_create_ah_resp resp = {};
u32 min_resp_len = offsetof(typeof(resp), dmac) +
sizeof(resp.dmac);
if (udata->outlen < min_resp_len)
return ERR_PTR(-EINVAL);
resp.response_length = min_resp_len;
err = ib_resolve_eth_dmac(pd->device, ah_attr);
if (err)
return ERR_PTR(err);
memcpy(resp.dmac, ah_attr->dmac, ETH_ALEN);
err = ib_copy_to_udata(udata, &resp, resp.response_length);
if (err)
return ERR_PTR(err);
}
ah = kzalloc(sizeof(*ah), GFP_ATOMIC);
if (!ah)
return ERR_PTR(-ENOMEM);
return create_ib_ah(dev, ah, ah_attr, ll); /* never fails */
}
int mlx5_ib_query_ah(struct ib_ah *ibah, struct ib_ah_attr *ah_attr)
{
struct mlx5_ib_ah *ah = to_mah(ibah);
u32 tmp;
memset(ah_attr, 0, sizeof(*ah_attr));
tmp = be32_to_cpu(ah->av.grh_gid_fl);
if (tmp & (1 << 30)) {
ah_attr->ah_flags = IB_AH_GRH;
ah_attr->grh.sgid_index = (tmp >> 20) & 0xff;
ah_attr->grh.flow_label = tmp & 0xfffff;
memcpy(&ah_attr->grh.dgid, ah->av.rgid, 16);
ah_attr->grh.hop_limit = ah->av.hop_limit;
ah_attr->grh.traffic_class = ah->av.tclass;
}
ah_attr->dlid = be16_to_cpu(ah->av.rlid);
ah_attr->static_rate = ah->av.stat_rate_sl >> 4;
ah_attr->sl = ah->av.stat_rate_sl & 0xf;
return 0;
}
int mlx5_ib_destroy_ah(struct ib_ah *ah)
{
kfree(to_mah(ah));
return 0;
}