[PATCH for-next 4/4] RDMA/efa: Expose RDMA read related attributes

[Gal Pressman <galpress@amazon.com>]

From: Daniel Kranzdorf <dkkranzd@amazon.com>

Query the device attributes for RDMA operations, including maximum
transfer size and maximum number of SGEs per RDMA WR, and report them
back to the userspace library.

Signed-off-by: Daniel Kranzdorf <dkkranzd@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
---
 drivers/infiniband/hw/efa/efa_admin_cmds_defs.h | 17 +++++++++++++++++
 drivers/infiniband/hw/efa/efa_com_cmd.c         |  2 ++
 drivers/infiniband/hw/efa/efa_com_cmd.h         |  2 ++
 drivers/infiniband/hw/efa/efa_verbs.c           |  2 ++
 include/uapi/rdma/efa-abi.h                     |  3 +++
 5 files changed, 26 insertions(+)

diff --git a/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h b/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
index 7fa9d532db61..e96bcb16bd2b 100644
--- a/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
+++ b/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
@@ -562,6 +562,16 @@ struct efa_admin_feature_device_attr_desc {
 
 	/* Indicates how many bits are used virtual address access */
 	u8 virt_addr_width;
+
+	/*
+	 * 0 : rdma_read - If set, RDMA Read is supported on
+	 *    TX queues
+	 * 31:1 : reserved - MBZ
+	 */
+	u32 device_caps;
+
+	/* Max RDMA transfer size in bytes */
+	u32 max_rdma_size;
 };
 
 struct efa_admin_feature_queue_attr_desc {
@@ -608,6 +618,9 @@ struct efa_admin_feature_queue_attr_desc {
 
 	/* The maximum size of LLQ in bytes */
 	u32 max_llq_size;
+
+	/* Maximum number of SGEs for a single RDMA read WQE */
+	u16 max_wr_rdma_sges;
 };
 
 struct efa_admin_feature_aenq_desc {
@@ -622,6 +635,7 @@ struct efa_admin_feature_network_attr_desc {
 	/* Raw address data in network byte order */
 	u8 addr[16];
 
+	/* max packet payload size in bytes */
 	u32 mtu;
 };
 
@@ -797,4 +811,7 @@ struct efa_admin_mmio_req_read_less_resp {
 /* get_set_feature_common_desc */
 #define EFA_ADMIN_GET_SET_FEATURE_COMMON_DESC_SELECT_MASK   GENMASK(1, 0)
 
+/* feature_device_attr_desc */
+#define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_RDMA_READ_MASK   BIT(0)
+
 #endif /* _EFA_ADMIN_CMDS_H_ */
diff --git a/drivers/infiniband/hw/efa/efa_com_cmd.c b/drivers/infiniband/hw/efa/efa_com_cmd.c
index 520c9d920f9e..0e6796f11e52 100644
--- a/drivers/infiniband/hw/efa/efa_com_cmd.c
+++ b/drivers/infiniband/hw/efa/efa_com_cmd.c
@@ -444,6 +444,7 @@ int efa_com_get_device_attr(struct efa_com_dev *edev,
 	result->phys_addr_width = resp.u.device_attr.phys_addr_width;
 	result->virt_addr_width = resp.u.device_attr.virt_addr_width;
 	result->db_bar = resp.u.device_attr.db_bar;
+	result->max_rdma_size = resp.u.device_attr.max_rdma_size;
 
 	if (result->admin_api_version < 1) {
 		ibdev_err_ratelimited(
@@ -477,6 +478,7 @@ int efa_com_get_device_attr(struct efa_com_dev *edev,
 	result->max_ah = resp.u.queue_attr.max_ah;
 	result->max_llq_size = resp.u.queue_attr.max_llq_size;
 	result->sub_cqs_per_cq = resp.u.queue_attr.sub_cqs_per_cq;
+	result->max_wr_rdma_sge = resp.u.queue_attr.max_wr_rdma_sges;
 
 	err = efa_com_get_feature(edev, &resp, EFA_ADMIN_NETWORK_ATTR);
 	if (err) {
diff --git a/drivers/infiniband/hw/efa/efa_com_cmd.h b/drivers/infiniband/hw/efa/efa_com_cmd.h
index d119186c41d0..4dd3452d0b41 100644
--- a/drivers/infiniband/hw/efa/efa_com_cmd.h
+++ b/drivers/infiniband/hw/efa/efa_com_cmd.h
@@ -121,9 +121,11 @@ struct efa_com_get_device_attr_result {
 	u32 max_pd;
 	u32 max_ah;
 	u32 max_llq_size;
+	u32 max_rdma_size;
 	u16 sub_cqs_per_cq;
 	u16 max_sq_sge;
 	u16 max_rq_sge;
+	u16 max_wr_rdma_sge;
 	u8 db_bar;
 };
 
diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 0011e2c1c8a6..188fcb41218d 100644
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -313,6 +313,8 @@ int efa_query_device(struct ib_device *ibdev,
 		resp.max_rq_sge = dev_attr->max_rq_sge;
 		resp.max_sq_wr = dev_attr->max_sq_depth;
 		resp.max_rq_wr = dev_attr->max_rq_depth;
+		resp.max_rdma_size = dev_attr->max_rdma_size;
+		resp.max_wr_rdma_sge = dev_attr->max_wr_rdma_sge;
 
 		err = ib_copy_to_udata(udata, &resp,
 				       min(sizeof(resp), udata->outlen));
diff --git a/include/uapi/rdma/efa-abi.h b/include/uapi/rdma/efa-abi.h
index 9599a2a62be8..269424c2a8a7 100644
--- a/include/uapi/rdma/efa-abi.h
+++ b/include/uapi/rdma/efa-abi.h
@@ -96,6 +96,9 @@ struct efa_ibv_ex_query_device_resp {
 	__u32 max_rq_wr;
 	__u16 max_sq_sge;
 	__u16 max_rq_sge;
+	__u32 max_rdma_size;
+	__u16 max_wr_rdma_sge;
+	__u8 reserved_b0[2];
 };
 
 #endif /* EFA_ABI_USER_H */
-- 
2.23.0