drivers/infiniband/hw/mlx5/ah.c

Source file repositories/reference/linux-study-clean/drivers/infiniband/hw/mlx5/ah.c

File Facts

System
Linux kernel
Corpus path
drivers/infiniband/hw/mlx5/ah.c
Extension
.c
Size
4877 bytes
Lines
155
Domain
Driver Families
Bucket
drivers/infiniband
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#include "mlx5_ib.h"

static __be16 mlx5_ah_get_udp_sport(const struct mlx5_ib_dev *dev,
				  const struct rdma_ah_attr *ah_attr)
{
	enum ib_gid_type gid_type = ah_attr->grh.sgid_attr->gid_type;
	__be16 sport;

	if ((gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP) &&
	    (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) &&
	    (ah_attr->grh.flow_label & IB_GRH_FLOWLABEL_MASK))
		sport = cpu_to_be16(
			rdma_flow_label_to_udp_sport(ah_attr->grh.flow_label));
	else
		sport = mlx5_get_roce_udp_sport_min(dev,
						    ah_attr->grh.sgid_attr);

	return sport;
}

static int create_ib_ah(struct mlx5_ib_dev *dev, struct mlx5_ib_ah *ah,
			 struct rdma_ah_init_attr *init_attr)
{
	struct rdma_ah_attr *ah_attr = init_attr->ah_attr;
	enum ib_gid_type gid_type;
	int rate_val;

	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
		const struct ib_global_route *grh = rdma_ah_read_grh(ah_attr);

		memcpy(ah->av.rgid, &grh->dgid, 16);
		ah->av.grh_gid_fl = cpu_to_be32(grh->flow_label |
						(1 << 30) |
						grh->sgid_index << 20);
		ah->av.hop_limit = grh->hop_limit;
		ah->av.tclass = grh->traffic_class;
	}

	rate_val = mlx5r_ib_rate(dev, rdma_ah_get_static_rate(ah_attr));
	if (rate_val < 0)
		return rate_val;
	ah->av.stat_rate_sl = rate_val << 4;

	if (ah_attr->type == RDMA_AH_ATTR_TYPE_ROCE) {
		if (init_attr->xmit_slave)
			ah->xmit_port =
				mlx5_lag_get_slave_port(dev->mdev,
							init_attr->xmit_slave);
		gid_type = ah_attr->grh.sgid_attr->gid_type;

		memcpy(ah->av.rmac, ah_attr->roce.dmac,
		       sizeof(ah_attr->roce.dmac));
		ah->av.udp_sport = mlx5_ah_get_udp_sport(dev, ah_attr);
		ah->av.stat_rate_sl |= (rdma_ah_get_sl(ah_attr) & 0x7) << 1;
		if (gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP)
#define MLX5_ECN_ENABLED BIT(1)
			ah->av.tclass |= MLX5_ECN_ENABLED;
	} else {
		ah->av.rlid = cpu_to_be16(rdma_ah_get_dlid(ah_attr));
		ah->av.fl_mlid = rdma_ah_get_path_bits(ah_attr) & 0x7f;
		ah->av.stat_rate_sl |= (rdma_ah_get_sl(ah_attr) & 0xf);
	}

	return 0;
}

int mlx5_ib_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
		      struct ib_udata *udata)

{
	struct rdma_ah_attr *ah_attr = init_attr->ah_attr;
	struct mlx5_ib_ah *ah = to_mah(ibah);
	struct mlx5_ib_dev *dev = to_mdev(ibah->device);
	enum rdma_ah_attr_type ah_type = ah_attr->type;

	if ((ah_type == RDMA_AH_ATTR_TYPE_ROCE) &&
	    !(rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH))
		return -EINVAL;

	if (ah_type == RDMA_AH_ATTR_TYPE_ROCE && udata) {
		int err;
		struct mlx5_ib_create_ah_resp resp = {};
		u32 min_resp_len =
			offsetofend(struct mlx5_ib_create_ah_resp, dmac);

		if (udata->outlen < min_resp_len)
			return -EINVAL;

		resp.response_length = min_resp_len;

Annotation

Implementation Notes