[SCSI] zfcp: Add support for unchained FSF requests

Add the support to send CT and ELS requests as unchained FSF requests. This is
required for older hardware and was somehow omitted during the cleanup of the
FSF layer. The req_count and resp_count attributes are unused, so remove them
instead of adding a special case for setting them. Also add debug data and a
warning, when the ct request hits a limit.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 31 insertions, 24 deletions

diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 217c3b0..eabdfe2 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -40,9 +40,12 @@ struct gpn_ft_resp_acc {
 	u64 wwpn;
 } __attribute__ ((packed));
 
-#define ZFCP_GPN_FT_ENTRIES ((PAGE_SIZE - sizeof(struct ct_hdr)) \
-				/ sizeof(struct gpn_ft_resp_acc))
+#define ZFCP_CT_SIZE_ONE_PAGE	(PAGE_SIZE - sizeof(struct ct_hdr))
+#define ZFCP_GPN_FT_ENTRIES	(ZFCP_CT_SIZE_ONE_PAGE \
+					/ sizeof(struct gpn_ft_resp_acc))
 #define ZFCP_GPN_FT_BUFFERS 4
+#define ZFCP_GPN_FT_MAX_SIZE (ZFCP_GPN_FT_BUFFERS * PAGE_SIZE \
+				- sizeof(struct ct_hdr))
 #define ZFCP_GPN_FT_MAX_ENTRIES ZFCP_GPN_FT_BUFFERS * (ZFCP_GPN_FT_ENTRIES + 1)
 
 struct ct_iu_gpn_ft_resp {
@@ -282,8 +285,6 @@ int static zfcp_fc_ns_gid_pn_request(struct zfcp_erp_action *erp_action,
 	gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
 	gid_pn->ct.req = &gid_pn->req;
 	gid_pn->ct.resp = &gid_pn->resp;
-	gid_pn->ct.req_count = 1;
-	gid_pn->ct.resp_count = 1;
 	sg_init_one(&gid_pn->req, &gid_pn->ct_iu_req,
 		    sizeof(struct ct_iu_gid_pn_req));
 	sg_init_one(&gid_pn->resp, &gid_pn->ct_iu_resp,
@@ -295,7 +296,7 @@ int static zfcp_fc_ns_gid_pn_request(struct zfcp_erp_action *erp_action,
 	gid_pn->ct_iu_req.header.gs_subtype = ZFCP_CT_NAME_SERVER;
 	gid_pn->ct_iu_req.header.options = ZFCP_CT_SYNCHRONOUS;
 	gid_pn->ct_iu_req.header.cmd_rsp_code = ZFCP_CT_GID_PN;
-	gid_pn->ct_iu_req.header.max_res_size = ZFCP_CT_MAX_SIZE;
+	gid_pn->ct_iu_req.header.max_res_size = ZFCP_CT_SIZE_ONE_PAGE / 4;
 	gid_pn->ct_iu_req.wwpn = erp_action->port->wwpn;
 
 	init_completion(&compl_rec.done);
@@ -405,8 +406,6 @@ static int zfcp_fc_adisc(struct zfcp_port *port)
 	sg_init_one(adisc->els.resp, &adisc->ls_adisc_acc,
 		    sizeof(struct zfcp_ls_adisc));
 
-	adisc->els.req_count = 1;
-	adisc->els.resp_count = 1;
 	adisc->els.adapter = adapter;
 	adisc->els.port = port;
 	adisc->els.d_id = port->d_id;
@@ -446,17 +445,17 @@ void zfcp_test_link(struct zfcp_port *port)
 		zfcp_erp_port_forced_reopen(port, 0, 65, NULL);
 }
 
-static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft)
+static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft, int buf_num)
 {
 	struct scatterlist *sg = &gpn_ft->sg_req;
 
 	kfree(sg_virt(sg)); /* free request buffer */
-	zfcp_sg_free_table(gpn_ft->sg_resp, ZFCP_GPN_FT_BUFFERS);
+	zfcp_sg_free_table(gpn_ft->sg_resp, buf_num);
 
 	kfree(gpn_ft);
 }
 
-static struct zfcp_gpn_ft *zfcp_alloc_sg_env(void)
+static struct zfcp_gpn_ft *zfcp_alloc_sg_env(int buf_num)
 {
 	struct zfcp_gpn_ft *gpn_ft;
 	struct ct_iu_gpn_ft_req *req;
@@ -473,8 +472,8 @@ static struct zfcp_gpn_ft *zfcp_alloc_sg_env(void)
 	}
 	sg_init_one(&gpn_ft->sg_req, req, sizeof(*req));
 
-	if (zfcp_sg_setup_table(gpn_ft->sg_resp, ZFCP_GPN_FT_BUFFERS)) {
-		zfcp_free_sg_env(gpn_ft);
+	if (zfcp_sg_setup_table(gpn_ft->sg_resp, buf_num)) {
+		zfcp_free_sg_env(gpn_ft, buf_num);
 		gpn_ft = NULL;
 	}
 out:
@@ -483,7 +482,8 @@ out:
 
 
 static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
-				  struct zfcp_adapter *adapter)
+				  struct zfcp_adapter *adapter,
+				  int max_bytes)
 {
 	struct zfcp_send_ct *ct = &gpn_ft->ct;
 	struct ct_iu_gpn_ft_req *req = sg_virt(&gpn_ft->sg_req);
@@ -496,8 +496,7 @@ static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
 	req->header.gs_subtype = ZFCP_CT_NAME_SERVER;
 	req->header.options = ZFCP_CT_SYNCHRONOUS;
 	req->header.cmd_rsp_code = ZFCP_CT_GPN_FT;
-	req->header.max_res_size = (sizeof(struct gpn_ft_resp_acc) *
-					(ZFCP_GPN_FT_MAX_ENTRIES - 1)) >> 2;
+	req->header.max_res_size = max_bytes / 4;
 	req->flags = 0;
 	req->domain_id_scope = 0;
 	req->area_id_scope = 0;
@@ -510,8 +509,6 @@ static int zfcp_scan_issue_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
 	ct->timeout = 10;
 	ct->req = &gpn_ft->sg_req;
 	ct->resp = gpn_ft->sg_resp;
-	ct->req_count = 1;
-	ct->resp_count = ZFCP_GPN_FT_BUFFERS;
 
 	init_completion(&compl_rec.done);
 	compl_rec.handler = NULL;
@@ -538,7 +535,7 @@ static void zfcp_validate_port(struct zfcp_port *port)
 	zfcp_port_dequeue(port);
 }
 
-static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft)
+static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
 {
 	struct zfcp_send_ct *ct = &gpn_ft->ct;
 	struct scatterlist *sg = gpn_ft->sg_resp;
@@ -558,13 +555,17 @@ static int zfcp_scan_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft)
 		return -EIO;
 	}
 
-	if (hdr->max_res_size)
+	if (hdr->max_res_size) {
+		dev_warn(&adapter->ccw_device->dev,
+			 "The name server reported %d words residual data\n",
+			 hdr->max_res_size);
 		return -E2BIG;
+	}
 
 	down(&zfcp_data.config_sema);
 
 	/* first entry is the header */
-	for (x = 1; x < ZFCP_GPN_FT_MAX_ENTRIES && !last; x++) {
+	for (x = 1; x < max_entries && !last; x++) {
 		if (x % (ZFCP_GPN_FT_ENTRIES + 1))
 			acc++;
 		else
@@ -609,6 +610,12 @@ int zfcp_scan_ports(struct zfcp_adapter *adapter)
 {
 	int ret, i;
 	struct zfcp_gpn_ft *gpn_ft;
+	int chain, max_entries, buf_num, max_bytes;
+
+	chain = adapter->adapter_features & FSF_FEATURE_ELS_CT_CHAINED_SBALS;
+	buf_num = chain ? ZFCP_GPN_FT_BUFFERS : 1;
+	max_entries = chain ? ZFCP_GPN_FT_MAX_ENTRIES : ZFCP_GPN_FT_ENTRIES;
+	max_bytes = chain ? ZFCP_GPN_FT_MAX_SIZE : ZFCP_CT_SIZE_ONE_PAGE;
 
 	if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT)
 		return 0;
@@ -617,23 +624,23 @@ int zfcp_scan_ports(struct zfcp_adapter *adapter)
 	if (ret)
 		return ret;
 
-	gpn_ft = zfcp_alloc_sg_env();
+	gpn_ft = zfcp_alloc_sg_env(buf_num);
 	if (!gpn_ft) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
 	for (i = 0; i < 3; i++) {
-		ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter);
+		ret = zfcp_scan_issue_gpn_ft(gpn_ft, adapter, max_bytes);
 		if (!ret) {
-			ret = zfcp_scan_eval_gpn_ft(gpn_ft);
+			ret = zfcp_scan_eval_gpn_ft(gpn_ft, max_entries);
 			if (ret == -EAGAIN)
 				ssleep(1);
 			else
 				break;
 		}
 	}
-	zfcp_free_sg_env(gpn_ft);
+	zfcp_free_sg_env(gpn_ft, buf_num);
 out:
 	zfcp_wka_port_put(&adapter->nsp);
 	return ret;