1 files changed, 433 insertions, 0 deletions
diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
new file mode 100644
index 000000000..8aeca7914
--- /dev/null
+++ b/drivers/ntb/test/ntb_pingpong.c
@@ -0,0 +1,433 @@
+/*
+ *   This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   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 copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Pingpong Linux driver
+ */
+
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
+ * Suppose aside from local device there is at least one remote device
+ * connected to NTB with index 0.
+ *-----------------------------------------------------------------------------
+ * Eg: install driver with specified delay between doorbell event and response
+ *
+ * root@self# insmod ntb_pingpong.ko delay_ms=1000
+ *-----------------------------------------------------------------------------
+ * Eg: get number of ping-pong cycles performed
+ *
+ * root@self# cat $DBG_DIR/count
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
+
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/hrtimer.h>
+#include <linux/debugfs.h>
+
+#include <linux/ntb.h>
+
+#define DRIVER_NAME		"ntb_pingpong"
+#define DRIVER_VERSION		"2.0"
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR("Allen Hubbe <Allen.Hubbe@emc.com>");
+MODULE_DESCRIPTION("PCIe NTB Simple Pingpong Client");
+
+static unsigned int unsafe;
+module_param(unsafe, uint, 0644);
+MODULE_PARM_DESC(unsafe, "Run even though ntb operations may be unsafe");
+
+static unsigned int delay_ms = 1000;
+module_param(delay_ms, uint, 0644);
+MODULE_PARM_DESC(delay_ms, "Milliseconds to delay the response to peer");
+
+struct pp_ctx {
+	struct ntb_dev *ntb;
+	struct hrtimer timer;
+	u64 in_db;
+	u64 out_db;
+	int out_pidx;
+	u64 nmask;
+	u64 pmask;
+	atomic_t count;
+	spinlock_t lock;
+	struct dentry *dbgfs_dir;
+};
+#define to_pp_timer(__timer) \
+	container_of(__timer, struct pp_ctx, timer)
+
+static struct dentry *pp_dbgfs_topdir;
+
+static int pp_find_next_peer(struct pp_ctx *pp)
+{
+	u64 link, out_db;
+	int pidx;
+
+	link = ntb_link_is_up(pp->ntb, NULL, NULL);
+
+	/* Find next available peer */
+	if (link & pp->nmask)
+		pidx = __ffs64(link & pp->nmask);
+	else if (link & pp->pmask)
+		pidx = __ffs64(link & pp->pmask);
+	else
+		return -ENODEV;
+
+	out_db = BIT_ULL(ntb_peer_port_number(pp->ntb, pidx));
+
+	spin_lock(&pp->lock);
+	pp->out_pidx = pidx;
+	pp->out_db = out_db;
+	spin_unlock(&pp->lock);
+
+	return 0;
+}
+
+static void pp_setup(struct pp_ctx *pp)
+{
+	int ret;
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+
+	hrtimer_cancel(&pp->timer);
+
+	ret = pp_find_next_peer(pp);
+	if (ret == -ENODEV) {
+		dev_dbg(&pp->ntb->dev, "Got no peers, so cancel\n");
+		return;
+	}
+
+	dev_dbg(&pp->ntb->dev, "Ping-pong started with port %d, db %#llx\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), pp->out_db);
+
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+}
+
+static void pp_clear(struct pp_ctx *pp)
+{
+	hrtimer_cancel(&pp->timer);
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+
+	dev_dbg(&pp->ntb->dev, "Ping-pong cancelled\n");
+}
+
+static void pp_ping(struct pp_ctx *pp)
+{
+	u32 count;
+
+	count = atomic_read(&pp->count);
+
+	spin_lock(&pp->lock);
+	ntb_peer_spad_write(pp->ntb, pp->out_pidx, 0, count);
+	ntb_peer_msg_write(pp->ntb, pp->out_pidx, 0, count);
+
+	dev_dbg(&pp->ntb->dev, "Ping port %d spad %#x, msg %#x\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), count, count);
+
+	ntb_peer_db_set(pp->ntb, pp->out_db);
+	ntb_db_clear_mask(pp->ntb, pp->in_db);
+	spin_unlock(&pp->lock);
+}
+
+static void pp_pong(struct pp_ctx *pp)
+{
+	u32 msg_data, spad_data;
+	int pidx = 0;
+
+	/* Read pong data */
+	spad_data = ntb_spad_read(pp->ntb, 0);
+	msg_data = ntb_msg_read(pp->ntb, &pidx, 0);
+	ntb_msg_clear_sts(pp->ntb, -1);
+
+	/*
+	 * Scratchpad and message data may differ, since message register can't
+	 * be rewritten unless status is cleared. Additionally either of them
+	 * might be unsupported
+	 */
+	dev_dbg(&pp->ntb->dev, "Pong spad %#x, msg %#x (port %d)\n",
+		spad_data, msg_data, ntb_peer_port_number(pp->ntb, pidx));
+
+	atomic_inc(&pp->count);
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+	ntb_db_clear(pp->ntb, pp->in_db);
+
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+}
+
+static enum hrtimer_restart pp_timer_func(struct hrtimer *t)
+{
+	struct pp_ctx *pp = to_pp_timer(t);
+
+	pp_ping(pp);
+
+	return HRTIMER_NORESTART;
+}
+
+static void pp_link_event(void *ctx)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_setup(pp);
+}
+
+static void pp_db_event(void *ctx, int vec)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_pong(pp);
+}
+
+static const struct ntb_ctx_ops pp_ops = {
+	.link_event = pp_link_event,
+	.db_event = pp_db_event
+};
+
+static int pp_check_ntb(struct ntb_dev *ntb)
+{
+	u64 pmask;
+
+	if (ntb_db_is_unsafe(ntb)) {
+		dev_dbg(&ntb->dev, "Doorbell is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
+	}
+
+	if (ntb_spad_is_unsafe(ntb)) {
+		dev_dbg(&ntb->dev, "Scratchpad is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
+	}
+
+	pmask = GENMASK_ULL(ntb_peer_port_count(ntb), 0);
+	if ((ntb_db_valid_mask(ntb) & pmask) != pmask) {
+		dev_err(&ntb->dev, "Unsupported DB configuration\n");
+		return -EINVAL;
+	}
+
+	if (ntb_spad_count(ntb) < 1 && ntb_msg_count(ntb) < 1) {
+		dev_err(&ntb->dev, "Scratchpads and messages unsupported\n");
+		return -EINVAL;
+	} else if (ntb_spad_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Scratchpads unsupported\n");
+	} else if (ntb_msg_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Messages unsupported\n");
+	}
+
+	return 0;
+}
+
+static struct pp_ctx *pp_create_data(struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+
+	pp = devm_kzalloc(&ntb->dev, sizeof(*pp), GFP_KERNEL);
+	if (!pp)
+		return ERR_PTR(-ENOMEM);
+
+	pp->ntb = ntb;
+	atomic_set(&pp->count, 0);
+	spin_lock_init(&pp->lock);
+	hrtimer_init(&pp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	pp->timer.function = pp_timer_func;
+
+	return pp;
+}
+
+static void pp_init_flds(struct pp_ctx *pp)
+{
+	int pidx, lport, pcnt;
+
+	/* Find global port index */
+	lport = ntb_port_number(pp->ntb);
+	pcnt = ntb_peer_port_count(pp->ntb);
+	for (pidx = 0; pidx < pcnt; pidx++) {
+		if (lport < ntb_peer_port_number(pp->ntb, pidx))
+			break;
+	}
+
+	pp->in_db = BIT_ULL(lport);
+	pp->pmask = GENMASK_ULL(pidx, 0) >> 1;
+	pp->nmask = GENMASK_ULL(pcnt - 1, pidx);
+
+	dev_dbg(&pp->ntb->dev, "Inbound db %#llx, prev %#llx, next %#llx\n",
+		pp->in_db, pp->pmask, pp->nmask);
+}
+
+static int pp_mask_events(struct pp_ctx *pp)
+{
+	u64 db_mask, msg_mask;
+	int ret;
+
+	db_mask = ntb_db_valid_mask(pp->ntb);
+	ret = ntb_db_set_mask(pp->ntb, db_mask);
+	if (ret)
+		return ret;
+
+	/* Skip message events masking if unsupported */
+	if (ntb_msg_count(pp->ntb) < 1)
+		return 0;
+
+	msg_mask = ntb_msg_outbits(pp->ntb) | ntb_msg_inbits(pp->ntb);
+	return ntb_msg_set_mask(pp->ntb, msg_mask);
+}
+
+static int pp_setup_ctx(struct pp_ctx *pp)
+{
+	int ret;
+
+	ret = ntb_set_ctx(pp->ntb, pp, &pp_ops);
+	if (ret)
+		return ret;
+
+	ntb_link_enable(pp->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	/* Might be not necessary */
+	ntb_link_event(pp->ntb);
+
+	return 0;
+}
+
+static void pp_clear_ctx(struct pp_ctx *pp)
+{
+	ntb_link_disable(pp->ntb);
+
+	ntb_clear_ctx(pp->ntb);
+}
+
+static void pp_setup_dbgfs(struct pp_ctx *pp)
+{
+	struct pci_dev *pdev = pp->ntb->pdev;
+
+	pp->dbgfs_dir = debugfs_create_dir(pci_name(pdev), pp_dbgfs_topdir);
+
+	debugfs_create_atomic_t("count", 0600, pp->dbgfs_dir, &pp->count);
+}
+
+static void pp_clear_dbgfs(struct pp_ctx *pp)
+{
+	debugfs_remove_recursive(pp->dbgfs_dir);
+}
+
+static int pp_probe(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+	int ret;
+
+	ret = pp_check_ntb(ntb);
+	if (ret)
+		return ret;
+
+	pp = pp_create_data(ntb);
+	if (IS_ERR(pp))
+		return PTR_ERR(pp);
+
+	pp_init_flds(pp);
+
+	ret = pp_mask_events(pp);
+	if (ret)
+		return ret;
+
+	ret = pp_setup_ctx(pp);
+	if (ret)
+		return ret;
+
+	pp_setup_dbgfs(pp);
+
+	return 0;
+}
+
+static void pp_remove(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp = ntb->ctx;
+
+	pp_clear_dbgfs(pp);
+
+	pp_clear_ctx(pp);
+
+	pp_clear(pp);
+}
+
+static struct ntb_client pp_client = {
+	.ops = {
+		.probe = pp_probe,
+		.remove = pp_remove
+	}
+};
+
+static int __init pp_init(void)
+{
+	int ret;
+
+	if (debugfs_initialized())
+		pp_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = ntb_register_client(&pp_client);
+	if (ret)
+		debugfs_remove_recursive(pp_dbgfs_topdir);
+
+	return ret;
+}
+module_init(pp_init);
+
+static void __exit pp_exit(void)
+{
+	ntb_unregister_client(&pp_client);
+	debugfs_remove_recursive(pp_dbgfs_topdir);
+}
+module_exit(pp_exit);