cxgb4: Add support to initialise/read SRQ entries

- This patch adds support to initialise srq table and read srq entries
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/Makefile

@@ -6,7 +6,7 @@
 obj-$(CONFIG_CHELSIO_T4) += cxgb4.o
 
 cxgb4-objs := cxgb4_main.o l2t.o smt.o t4_hw.o sge.o clip_tbl.o cxgb4_ethtool.o \
-	      cxgb4_uld.o sched.o cxgb4_filter.o cxgb4_tc_u32.o \
+	      cxgb4_uld.o srq.o sched.o cxgb4_filter.o cxgb4_tc_u32.o \
 	      cxgb4_ptp.o cxgb4_tc_flower.o cxgb4_cudbg.o \
 	      cudbg_common.o cudbg_lib.o cudbg_zlib.o
 cxgb4-$(CONFIG_CHELSIO_T4_DCB) +=  cxgb4_dcb.o

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -960,6 +960,8 @@ struct adapter {
 
 	/* HMA */
 	struct hma_data hma;
+
+	struct srq_data *srq;
 };
 
 /* Support for "sched-class" command to allow a TX Scheduling Class to be

drivers/net/ethernet/chelsio/cxgb4/srq.c

+/*
+ * This file is part of the Chelsio T6 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2017-2018 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "cxgb4.h"
+#include "t4_msg.h"
+#include "srq.h"
+
+struct srq_data *t4_init_srq(int srq_size)
+{
+	struct srq_data *s;
+
+	s = kvzalloc(sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return NULL;
+
+	s->srq_size = srq_size;
+	init_completion(&s->comp);
+	mutex_init(&s->lock);
+
+	return s;
+}
+
+/* cxgb4_get_srq_entry: read the SRQ table entry
+ * @dev: Pointer to the net_device
+ * @idx: Index to the srq
+ * @entryp: pointer to the srq entry
+ *
+ * Sends CPL_SRQ_TABLE_REQ message for the given index.
+ * Contents will be returned in CPL_SRQ_TABLE_RPL message.
+ *
+ * Returns zero if the read is successful, else a error
+ * number will be returned. Caller should not use the srq
+ * entry if the return value is non-zero.
+ *
+ *
+ */
+int cxgb4_get_srq_entry(struct net_device *dev,
+			int srq_idx, struct srq_entry *entryp)
+{
+	struct cpl_srq_table_req *req;
+	struct adapter *adap;
+	struct sk_buff *skb;
+	struct srq_data *s;
+	int rc = -ENODEV;
+
+	adap = netdev2adap(dev);
+	s = adap->srq;
+
+	if (!(adap->flags & FULL_INIT_DONE) || !s)
+		goto out;
+
+	skb = alloc_skb(sizeof(*req), GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+	req = (struct cpl_srq_table_req *)
+		__skb_put(skb, sizeof(*req));
+	memset(req, 0, sizeof(*req));
+	INIT_TP_WR(req, 0);
+	OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_SRQ_TABLE_REQ,
+					      TID_TID_V(srq_idx) |
+				TID_QID_V(adap->sge.fw_evtq.abs_id)));
+	req->idx = srq_idx;
+
+	mutex_lock(&s->lock);
+
+	s->entryp = entryp;
+	t4_mgmt_tx(adap, skb);
+
+	rc = wait_for_completion_timeout(&s->comp, SRQ_WAIT_TO);
+	if (rc)
+		rc = 0;
+	else /* !rc means we timed out */
+		rc = -ETIMEDOUT;
+
+	WARN_ON_ONCE(entryp->idx != srq_idx);
+	mutex_unlock(&s->lock);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(cxgb4_get_srq_entry);
+
+void do_srq_table_rpl(struct adapter *adap,
+		      const struct cpl_srq_table_rpl *rpl)
+{
+	unsigned int idx = TID_TID_G(GET_TID(rpl));
+	struct srq_data *s = adap->srq;
+	struct srq_entry *e;
+
+	if (unlikely(rpl->status != CPL_CONTAINS_READ_RPL)) {
+		dev_err(adap->pdev_dev,
+			"Unexpected SRQ_TABLE_RPL status %u for entry %u\n",
+				rpl->status, idx);
+		goto out;
+	}
+
+	/* Store the read entry */
+	e = s->entryp;
+	e->valid = 1;
+	e->idx = idx;
+	e->pdid = SRQT_PDID_G(be64_to_cpu(rpl->rsvd_pdid));
+	e->qlen = SRQT_QLEN_G(be32_to_cpu(rpl->qlen_qbase));
+	e->qbase = SRQT_QBASE_G(be32_to_cpu(rpl->qlen_qbase));
+	e->cur_msn = be16_to_cpu(rpl->cur_msn);
+	e->max_msn = be16_to_cpu(rpl->max_msn);
+out:
+	complete(&s->comp);
+}

drivers/net/ethernet/chelsio/cxgb4/srq.h

+/*
+ * This file is part of the Chelsio T6 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2017-2018 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef __CXGB4_SRQ_H
+#define __CXGB4_SRQ_H
+
+struct adapter;
+struct cpl_srq_table_rpl;
+
+#define SRQ_WAIT_TO	(HZ * 5)
+
+struct srq_entry {
+	u8 valid;
+	u8 idx;
+	u8 qlen;
+	u16 pdid;
+	u16 cur_msn;
+	u16 max_msn;
+	u32 qbase;
+};
+
+struct srq_data {
+	unsigned int srq_size;
+	struct srq_entry *entryp;
+	struct completion comp;
+	struct mutex lock; /* generic mutex for srq data */
+};
+
+struct srq_data *t4_init_srq(int srq_size);
+int cxgb4_get_srq_entry(struct net_device *dev,
+			int srq_idx, struct srq_entry *entryp);
+void do_srq_table_rpl(struct adapter *adap,
+		      const struct cpl_srq_table_rpl *rpl);
+#endif  /* __CXGB4_SRQ_H */