Re: [PATCH 6/8] RDMA/bng_re: Enable Firmware channel and query device attributes

On Fri, Aug 29, 2025 at 12:30:40PM +0000, Siva Reddy Kallam wrote:

Enable Firmware channel and query device attributes

Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
Reviewed-by: Usman Ansari <redacted>

...

...

+int bng_re_get_dev_attr(struct bng_re_rcfw *rcfw)
+{
+	struct bng_re_dev_attr *attr = rcfw->res->dattr;
+	struct creq_query_func_resp resp = {};
+	struct bng_re_cmdqmsg msg = {};
+	struct creq_query_func_resp_sb *sb;
+	struct bng_re_rcfw_sbuf sbuf;
+	struct bng_re_chip_ctx *cctx;
+	struct cmdq_query_func req = {};
+	u8 *tqm_alloc;
+	int i, rc;
+	u32 temp;
+
+	cctx = rcfw->res->cctx;

Similar to my comment on an earlier patch in this series,
cctx appears to be initialised but otherwise unused in this function.

+	bng_re_rcfw_cmd_prep((struct cmdq_base *)&req,
+			     CMDQ_BASE_OPCODE_QUERY_FUNC,
+			     sizeof(req));
+
+	sbuf.size = ALIGN(sizeof(*sb), BNG_FW_CMDQE_UNITS);
+	sbuf.sb = dma_alloc_coherent(&rcfw->pdev->dev, sbuf.size,
+				     &sbuf.dma_addr, GFP_KERNEL);
+	if (!sbuf.sb)
+		return -ENOMEM;
+	sb = sbuf.sb;
+	req.resp_size = sbuf.size / BNG_FW_CMDQE_UNITS;
+	bng_re_fill_cmdqmsg(&msg, &req, &resp, &sbuf, sizeof(req),
+			    sizeof(resp), 0);
+	rc = bng_re_rcfw_send_message(rcfw, &msg);
+	if (rc)
+		goto bail;
+	/* Extract the context from the side buffer */
+	attr->max_qp = le32_to_cpu(sb->max_qp);
+	/* max_qp value reported by FW doesn't include the QP1 */
+	attr->max_qp += 1;
+	attr->max_qp_rd_atom =
+		sb->max_qp_rd_atom > BNG_RE_MAX_OUT_RD_ATOM ?
+		BNG_RE_MAX_OUT_RD_ATOM : sb->max_qp_rd_atom;
+	attr->max_qp_init_rd_atom =
+		sb->max_qp_init_rd_atom > BNG_RE_MAX_OUT_RD_ATOM ?
+		BNG_RE_MAX_OUT_RD_ATOM : sb->max_qp_init_rd_atom;
+	attr->max_qp_wqes = le16_to_cpu(sb->max_qp_wr) - 1;
+
+	/* Adjust for max_qp_wqes for variable wqe */
+	attr->max_qp_wqes = min_t(u32, attr->max_qp_wqes, BNG_VAR_MAX_WQE - 1);
+
+	attr->max_qp_sges = min_t(u32, sb->max_sge_var_wqe, BNG_VAR_MAX_SGE);
+	attr->max_cq = le32_to_cpu(sb->max_cq);
+	attr->max_cq_wqes = le32_to_cpu(sb->max_cqe);
+	attr->max_cq_sges = attr->max_qp_sges;
+	attr->max_mr = le32_to_cpu(sb->max_mr);
+	attr->max_mw = le32_to_cpu(sb->max_mw);
+
+	attr->max_mr_size = le64_to_cpu(sb->max_mr_size);
+	attr->max_pd = 64 * 1024;
+	attr->max_raw_ethy_qp = le32_to_cpu(sb->max_raw_eth_qp);
+	attr->max_ah = le32_to_cpu(sb->max_ah);
+
+	attr->max_srq = le16_to_cpu(sb->max_srq);
+	attr->max_srq_wqes = le32_to_cpu(sb->max_srq_wr) - 1;
+	attr->max_srq_sges = sb->max_srq_sge;
+	attr->max_pkey = 1;
+	attr->max_inline_data = le32_to_cpu(sb->max_inline_data);
+	/*
+	 * Read the max gid supported by HW.
+	 * For each entry in HW  GID in HW table, we consume 2
+	 * GID entries in the kernel GID table.  So max_gid reported
+	 * to stack can be up to twice the value reported by the HW, up to 256 gids.
+	 */
+	attr->max_sgid = le32_to_cpu(sb->max_gid);
+	attr->max_sgid = min_t(u32, BNG_RE_NUM_GIDS_SUPPORTED, 2 * attr->max_sgid);
+	attr->dev_cap_flags = le16_to_cpu(sb->dev_cap_flags);
+	attr->dev_cap_flags2 = le16_to_cpu(sb->dev_cap_ext_flags_2);
+
+	if (_is_max_srq_ext_supported(attr->dev_cap_flags2))
+		attr->max_srq += le16_to_cpu(sb->max_srq_ext);
+
+	bng_re_query_version(rcfw, attr->fw_ver);
+	for (i = 0; i < BNG_MAX_TQM_ALLOC_REQ / 4; i++) {
+		temp = le32_to_cpu(sb->tqm_alloc_reqs[i]);
+		tqm_alloc = (u8 *)&temp;
+		attr->tqm_alloc_reqs[i * 4] = *tqm_alloc;
+		attr->tqm_alloc_reqs[i * 4 + 1] = *(++tqm_alloc);
+		attr->tqm_alloc_reqs[i * 4 + 2] = *(++tqm_alloc);
+		attr->tqm_alloc_reqs[i * 4 + 3] = *(++tqm_alloc);
+	}
+
+	attr->max_dpi = le32_to_cpu(sb->max_dpi);
+	attr->is_atomic = bng_re_is_atomic_cap(rcfw);
+bail:
+	dma_free_coherent(&rcfw->pdev->dev, sbuf.size,
+			  sbuf.sb, sbuf.dma_addr);
+	return rc;
+}

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