RDMA/sa_query: Support IB service records resolution

Add an SA query API ib_sa_service_rec_get() to support building and
sending SA query MADs that ask for service records with a specific
name or ID, and receiving and parsing responses from the SM.

Signed-off-by: Or Har-Toov <[e-mail]>
Signed-off-by: Mark Zhang <[e-mail]>
Reviewed-by: Vlad Dumitrescu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Leon Romanovsky <[e-mail]>

drivers/infiniband/core/sa_query.c

···
 	struct ib_sa_query sa_query;
 };
 
+struct ib_sa_service_query {
+	void (*callback)(int status, struct sa_service_rec *rec,
+			 unsigned int num_services, void *context);
+	void *context;
+	struct ib_sa_query sa_query;
+};
+
 static LIST_HEAD(ib_nl_request_list);
 static DEFINE_SPINLOCK(ib_nl_request_lock);
 static atomic_t ib_nl_sa_request_seq;
···
 	  .offset_words = 2,
 	  .offset_bits  = 0,
 	  .size_bits    = 512 },
+};
+
+#define SERVICE_REC_FIELD(field) \
+	.struct_offset_bytes = offsetof(struct sa_service_rec, field),     \
+	.struct_size_bytes   = sizeof_field(struct sa_service_rec, field), \
+	.field_name          = "sa_service_rec:" #field
+
+static const struct ib_field service_rec_table[] = {
+	{ SERVICE_REC_FIELD(id),
+	  .offset_words = 0,
+	  .offset_bits  = 0,
+	  .size_bits    = 64 },
+	{ SERVICE_REC_FIELD(gid),
+	  .offset_words = 2,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
+	{ SERVICE_REC_FIELD(pkey),
+	  .offset_words = 6,
+	  .offset_bits  = 0,
+	  .size_bits    = 16 },
+	{ RESERVED,
+	  .offset_words = 6,
+	  .offset_bits  = 16,
+	  .size_bits    = 16 },
+	{ SERVICE_REC_FIELD(lease),
+	  .offset_words = 7,
+	  .offset_bits  = 0,
+	  .size_bits    = 32 },
+	{ SERVICE_REC_FIELD(key),
+	  .offset_words = 8,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
+	{ SERVICE_REC_FIELD(name),
+	  .offset_words = 12,
+	  .offset_bits  = 0,
+	  .size_bits    = 512 },
+	{ SERVICE_REC_FIELD(data_8),
+	  .offset_words = 28,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
+	{ SERVICE_REC_FIELD(data_16),
+	  .offset_words = 32,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
+	{ SERVICE_REC_FIELD(data_32),
+	  .offset_words = 36,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
+	{ SERVICE_REC_FIELD(data_64),
+	  .offset_words = 40,
+	  .offset_bits  = 0,
+	  .size_bits    = 128 },
 };
 
 #define RDMA_PRIMARY_PATH_MAX_REC_NUM 3
···
 }
 EXPORT_SYMBOL(ib_sa_pack_path);
 
+void ib_sa_pack_service(struct sa_service_rec *rec, void *attribute)
+{
+	ib_pack(service_rec_table, ARRAY_SIZE(service_rec_table), rec,
+		attribute);
+}
+EXPORT_SYMBOL(ib_sa_pack_service);
+
+void ib_sa_unpack_service(void *attribute, struct sa_service_rec *rec)
+{
+	ib_unpack(service_rec_table, ARRAY_SIZE(service_rec_table), attribute,
+		  rec);
+}
+EXPORT_SYMBOL(ib_sa_unpack_service);
+
 static bool ib_sa_opa_pathrecord_support(struct ib_sa_client *client,
 					 struct ib_sa_device *sa_dev,
 					 u32 port_num)
···
 	}
 }
 
+#define IB_SA_DATA_OFFS 56
+#define IB_SERVICE_REC_SZ 176
+
+static void ib_unpack_service_rmpp(struct sa_service_rec *rec,
+				   struct ib_mad_recv_wc *mad_wc,
+				   int num_services)
+{
+	unsigned int cp_sz, data_i, data_size, rec_i = 0, buf_i = 0;
+	struct ib_mad_recv_buf *mad_buf;
+	u8 buf[IB_SERVICE_REC_SZ];
+	u8 *data;
+
+	data_size = sizeof(((struct ib_sa_mad *) mad_buf->mad)->data);
+
+	list_for_each_entry(mad_buf, &mad_wc->rmpp_list, list) {
+		data = ((struct ib_sa_mad *) mad_buf->mad)->data;
+		data_i = 0;
+		while (data_i < data_size && rec_i < num_services) {
+			cp_sz = min(IB_SERVICE_REC_SZ - buf_i,
+				    data_size - data_i);
+			memcpy(buf + buf_i, data + data_i, cp_sz);
+			data_i += cp_sz;
+			buf_i += cp_sz;
+			if (buf_i == IB_SERVICE_REC_SZ) {
+				ib_sa_unpack_service(buf, rec + rec_i);
+				buf_i = 0;
+				rec_i++;
+			}
+		}
+	}
+}
+
+static void ib_sa_service_rec_callback(struct ib_sa_query *sa_query, int status,
+				       struct ib_mad_recv_wc *mad_wc)
+{
+	struct ib_sa_service_query *query =
+		container_of(sa_query, struct ib_sa_service_query, sa_query);
+	struct sa_service_rec *rec;
+	int num_services;
+
+	if (!mad_wc || !mad_wc->recv_buf.mad) {
+		query->callback(status, NULL, 0, query->context);
+		return;
+	}
+
+	num_services = (mad_wc->mad_len - IB_SA_DATA_OFFS) / IB_SERVICE_REC_SZ;
+	if (!num_services) {
+		query->callback(-ENODATA, NULL, 0, query->context);
+		return;
+	}
+
+	rec = kmalloc_array(num_services, sizeof(*rec), GFP_KERNEL);
+	if (!rec) {
+		query->callback(-ENOMEM, NULL, 0, query->context);
+		return;
+	}
+
+	ib_unpack_service_rmpp(rec, mad_wc, num_services);
+	query->callback(status, rec, num_services, query->context);
+	kfree(rec);
+}
+
 static void ib_sa_path_rec_release(struct ib_sa_query *sa_query)
 {
 	struct ib_sa_path_query *query =
 		container_of(sa_query, struct ib_sa_path_query, sa_query);
 
 	kfree(query->conv_pr);
+	kfree(query);
+}
+
+static void ib_sa_service_rec_release(struct ib_sa_query *sa_query)
+{
+	struct ib_sa_service_query *query =
+		container_of(sa_query, struct ib_sa_service_query, sa_query);
+
 	kfree(query);
 }
 
···
 	return ret;
 }
 EXPORT_SYMBOL(ib_sa_path_rec_get);
+
+/**
+ * ib_sa_service_rec_get - Start a Service get query
+ * @client: SA client
+ * @device: device to send query on
+ * @port_num: port number to send query on
+ * @rec: Service Record to send in query
+ * @comp_mask: component mask to send in query
+ * @timeout_ms: time to wait for response
+ * @gfp_mask: GFP mask to use for internal allocations
+ * @callback: function called when query completes, times out or is
+ * canceled
+ * @context: opaque user context passed to callback
+ * @sa_query: query context, used to cancel query
+ *
+ * Send a Service Record Get query to the SA to look up a path.  The
+ * callback function will be called when the query completes (or
+ * fails); status is 0 for a successful response, -EINTR if the query
+ * is canceled, -ETIMEDOUT is the query timed out, or -EIO if an error
+ * occurred sending the query.  The resp parameter of the callback is
+ * only valid if status is 0.
+ *
+ * If the return value of ib_sa_service_rec_get() is negative, it is an
+ * error code. Otherwise it is a query ID that can be used to cancel
+ * the query.
+ */
+int ib_sa_service_rec_get(struct ib_sa_client *client,
+			  struct ib_device *device, u32 port_num,
+			  struct sa_service_rec *rec,
+			  ib_sa_comp_mask comp_mask,
+			  unsigned long timeout_ms, gfp_t gfp_mask,
+			  void (*callback)(int status,
+					   struct sa_service_rec *resp,
+					   unsigned int num_services,
+					   void *context),
+			  void *context, struct ib_sa_query **sa_query)
+{
+	struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
+	struct ib_sa_service_query *query;
+	struct ib_mad_agent *agent;
+	struct ib_sa_port   *port;
+	struct ib_sa_mad *mad;
+	int ret;
+
+	if (!sa_dev)
+		return -ENODEV;
+
+	port = &sa_dev->port[port_num - sa_dev->start_port];
+	agent = port->agent;
+
+	query = kzalloc(sizeof(*query), gfp_mask);
+	if (!query)
+		return -ENOMEM;
+
+	query->sa_query.port = port;
+
+	ret = alloc_mad(&query->sa_query, gfp_mask);
+	if (ret)
+		goto err1;
+
+	ib_sa_client_get(client);
+	query->sa_query.client = client;
+	query->callback        = callback;
+	query->context         = context;
+
+	mad = query->sa_query.mad_buf->mad;
+	init_mad(&query->sa_query, agent);
+
+	query->sa_query.rmpp_callback = callback ? ib_sa_service_rec_callback :
+		NULL;
+	query->sa_query.release = ib_sa_service_rec_release;
+	mad->mad_hdr.method	= IB_MGMT_METHOD_GET_TABLE;
+	mad->mad_hdr.attr_id	= cpu_to_be16(IB_SA_ATTR_SERVICE_REC);
+	mad->sa_hdr.comp_mask	= comp_mask;
+
+	ib_sa_pack_service(rec, mad->data);
+
+	*sa_query = &query->sa_query;
+	query->sa_query.mad_buf->context[1] = rec;
+
+	ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
+	if (ret < 0)
+		goto err2;
+
+	return ret;
+
+err2:
+	*sa_query = NULL;
+	ib_sa_client_put(query->sa_query.client);
+	free_mad(&query->sa_query);
+err1:
+	kfree(query);
+	return ret;
+}
+EXPORT_SYMBOL(ib_sa_service_rec_get);
 
 static void ib_sa_mcmember_rec_callback(struct ib_sa_query *sa_query,
 					int status, struct ib_sa_mad *mad)

include/rdma/ib_mad.h

···
 #define IB_MGMT_METHOD_REPORT			0x06
 #define IB_MGMT_METHOD_REPORT_RESP		0x86
 #define IB_MGMT_METHOD_TRAP_REPRESS		0x07
+#define IB_MGMT_METHOD_GET_TABLE		0x12
 
 #define IB_MGMT_METHOD_RESP			0x80
 #define IB_BM_ATTR_MOD_RESP			cpu_to_be32(1)

include/rdma/ib_sa.h

···
 	u32 flags;
 };
 
+struct sa_service_rec {
+	__be64 id;
+	__u8 gid[16];
+	__be16 pkey;
+	__u8 reserved[2];
+	__be32 lease;
+	__u8 key[16];
+	__u8 name[64];
+	__u8 data_8[16];
+	__be16 data_16[8];
+	__be32 data_32[4];
+	__be64 data_64[2];
+};
+
 static inline enum ib_gid_type
 		sa_conv_pathrec_to_gid_type(struct sa_path_rec *rec)
 {
···
 					unsigned int num_prs, void *context),
 		       void *context, struct ib_sa_query **query);
 
+int ib_sa_service_rec_get(struct ib_sa_client *client,
+			  struct ib_device *device, u32 port_num,
+			  struct sa_service_rec *rec,
+			  ib_sa_comp_mask comp_mask,
+			  unsigned long timeout_ms, gfp_t gfp_mask,
+			  void (*callback)(int status,
+					   struct sa_service_rec *resp,
+					   unsigned int num_services,
+					   void *context),
+			  void *context, struct ib_sa_query **sa_query);
+
 struct ib_sa_multicast {
 	struct ib_sa_mcmember_rec rec;
 	ib_sa_comp_mask		comp_mask;
···
  * to IB MAD wire format.
  */
 void ib_sa_pack_path(struct sa_path_rec *rec, void *attribute);
+
+/**
+ * ib_sa_pack_service - Convert a service record from struct ib_sa_service_rec
+ * to IB MAD wire format.
+ */
+void ib_sa_pack_service(struct sa_service_rec *rec, void *attribute);
+
+/**
+ * ib_sa_unpack_service - Convert a service record from MAD format to struct
+ * ib_sa_service_rec.
+ */
+void ib_sa_unpack_service(void *attribute, struct sa_service_rec *rec);
 
 /**
  * ib_sa_unpack_path - Convert a path record from MAD format to struct