[mirror_ubuntu-bionic-kernel.git] / drivers / ntb / test / ntb_pingpong.c

/*
 * 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.
 *
 *   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.
 *
 *   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
 *
 * Contact Information:
 * Allen Hubbe <Allen.Hubbe@emc.com>
 */

/* Note: load this module with option 'dyndbg=+p' */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

#include <linux/dma-mapping.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <linux/ntb.h>

#define DRIVER_NAME			"ntb_pingpong"
#define DRIVER_DESCRIPTION		"PCIe NTB Simple Pingpong Client"

#define DRIVER_LICENSE			"Dual BSD/GPL"
#define DRIVER_VERSION			"1.0"
#define DRIVER_RELDATE			"24 March 2015"
#define DRIVER_AUTHOR			"Allen Hubbe <Allen.Hubbe@emc.com>"

MODULE_LICENSE(DRIVER_LICENSE);
MODULE_VERSION(DRIVER_VERSION);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION);

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");

static unsigned long db_init = 0x7;
module_param(db_init, ulong, 0644);
MODULE_PARM_DESC(delay_ms, "Initial doorbell bits to ring on the peer");

struct pp_ctx {
	struct ntb_dev			*ntb;
	u64				db_bits;
	/* synchronize access to db_bits by ping and pong */
	spinlock_t			db_lock;
	struct timer_list		db_timer;
	unsigned long			db_delay;
};

static void pp_ping(unsigned long ctx)
{
	struct pp_ctx *pp = (void *)ctx;
	unsigned long irqflags;
	u64 db_bits, db_mask;
	u32 spad_rd, spad_wr;

	spin_lock_irqsave(&pp->db_lock, irqflags);
	{
		db_mask = ntb_db_valid_mask(pp->ntb);
		db_bits = ntb_db_read(pp->ntb);

		if (db_bits) {
			dev_dbg(&pp->ntb->dev,
				"Masked pongs %#llx\n",
				db_bits);
			ntb_db_clear(pp->ntb, db_bits);
		}

		db_bits = ((pp->db_bits | db_bits) << 1) & db_mask;

		if (!db_bits)
			db_bits = db_init;

		spad_rd = ntb_spad_read(pp->ntb, 0);
		spad_wr = spad_rd + 1;

		dev_dbg(&pp->ntb->dev,
			"Ping bits %#llx read %#x write %#x\n",
			db_bits, spad_rd, spad_wr);

		ntb_peer_spad_write(pp->ntb, 0, spad_wr);
		ntb_peer_db_set(pp->ntb, db_bits);
		ntb_db_clear_mask(pp->ntb, db_mask);

		pp->db_bits = 0;
	}
	spin_unlock_irqrestore(&pp->db_lock, irqflags);
}

static void pp_link_event(void *ctx)
{
	struct pp_ctx *pp = ctx;

	if (ntb_link_is_up(pp->ntb, NULL, NULL) == 1) {
		dev_dbg(&pp->ntb->dev, "link is up\n");
		pp_ping((unsigned long)pp);
	} else {
		dev_dbg(&pp->ntb->dev, "link is down\n");
		del_timer(&pp->db_timer);
	}
}

static void pp_db_event(void *ctx, int vec)
{
	struct pp_ctx *pp = ctx;
	u64 db_bits, db_mask;
	unsigned long irqflags;

	spin_lock_irqsave(&pp->db_lock, irqflags);
	{
		db_mask = ntb_db_vector_mask(pp->ntb, vec);
		db_bits = db_mask & ntb_db_read(pp->ntb);
		ntb_db_set_mask(pp->ntb, db_mask);
		ntb_db_clear(pp->ntb, db_bits);

		pp->db_bits |= db_bits;

		mod_timer(&pp->db_timer, jiffies + pp->db_delay);

		dev_dbg(&pp->ntb->dev,
			"Pong vec %d bits %#llx\n",
			vec, db_bits);
	}
	spin_unlock_irqrestore(&pp->db_lock, irqflags);
}

static const struct ntb_ctx_ops pp_ops = {
	.link_event = pp_link_event,
	.db_event = pp_db_event,
};

static int pp_probe(struct ntb_client *client,
		    struct ntb_dev *ntb)
{
	struct pp_ctx *pp;
	int rc;

	if (ntb_db_is_unsafe(ntb)) {
		dev_dbg(&ntb->dev, "doorbell is unsafe\n");
		if (!unsafe) {
			rc = -EINVAL;
			goto err_pp;
		}
	}

	if (ntb_spad_is_unsafe(ntb)) {
		dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
		if (!unsafe) {
			rc = -EINVAL;
			goto err_pp;
		}
	}

	pp = kmalloc(sizeof(*pp), GFP_KERNEL);
	if (!pp) {
		rc = -ENOMEM;
		goto err_pp;
	}

	pp->ntb = ntb;
	pp->db_bits = 0;
	spin_lock_init(&pp->db_lock);
	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
	pp->db_delay = msecs_to_jiffies(delay_ms);

	rc = ntb_set_ctx(ntb, pp, &pp_ops);
	if (rc)
		goto err_ctx;

	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
	ntb_link_event(ntb);

	return 0;

err_ctx:
	kfree(pp);
err_pp:
	return rc;
}

static void pp_remove(struct ntb_client *client,
		      struct ntb_dev *ntb)
{
	struct pp_ctx *pp = ntb->ctx;

	ntb_clear_ctx(ntb);
	del_timer_sync(&pp->db_timer);
	ntb_link_disable(ntb);

	kfree(pp);
}

static struct ntb_client pp_client = {
	.ops = {
		.probe = pp_probe,
		.remove = pp_remove,
	},
};
module_ntb_client(pp_client);
Commit	Line	Data
963de473 AH	1	/*
	2	* This file is provided under a dual BSD/GPLv2 license. When using or
	3	* redistributing this file, you may do so under either license.
	4	*
	5	* GPL LICENSE SUMMARY
	6	*
	7	* Copyright (C) 2015 EMC Corporation. All Rights Reserved.
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of version 2 of the GNU General Public License as
	11	* published by the Free Software Foundation.
	12	*
	13	* This program is distributed in the hope that it will be useful, but
	14	* WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* General Public License for more details.
	17	*
	18	* BSD LICENSE
	19	*
	20	* Copyright (C) 2015 EMC Corporation. All Rights Reserved.
	21	*
	22	* Redistribution and use in source and binary forms, with or without
	23	* modification, are permitted provided that the following conditions
	24	* are met:
	25	*
	26	* * Redistributions of source code must retain the above copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* * Redistributions in binary form must reproduce the above copy
	29	* notice, this list of conditions and the following disclaimer in
	30	* the documentation and/or other materials provided with the
	31	* distribution.
	32	* * Neither the name of Intel Corporation nor the names of its
	33	* contributors may be used to endorse or promote products derived
	34	* from this software without specific prior written permission.
	35	*
	36	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	37	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	38	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	39	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	40	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	41	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	42	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	43	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	44	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	45	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	46	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	47	*
	48	* PCIe NTB Pingpong Linux driver
	49	*
	50	* Contact Information:
	51	* Allen Hubbe <Allen.Hubbe@emc.com>
	52	*/
	53
	54	/* Note: load this module with option 'dyndbg=+p' */
	55
	56	#include <linux/init.h>
	57	#include <linux/kernel.h>
	58	#include <linux/module.h>
	59
	60	#include <linux/dma-mapping.h>
	61	#include <linux/pci.h>
	62	#include <linux/slab.h>
	63	#include <linux/spinlock.h>
	64
65	#include <linux/ntb.h>
66
67	#define DRIVER_NAME "ntb_pingpong"
68	#define DRIVER_DESCRIPTION "PCIe NTB Simple Pingpong Client"
69
70	#define DRIVER_LICENSE "Dual BSD/GPL"
71	#define DRIVER_VERSION "1.0"
72	#define DRIVER_RELDATE "24 March 2015"
73	#define DRIVER_AUTHOR "Allen Hubbe <Allen.Hubbe@emc.com>"
74
75	MODULE_LICENSE(DRIVER_LICENSE);
76	MODULE_VERSION(DRIVER_VERSION);
77	MODULE_AUTHOR(DRIVER_AUTHOR);
78	MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
79
80	static unsigned int unsafe;
81	module_param(unsafe, uint, 0644);
82	MODULE_PARM_DESC(unsafe, "Run even though ntb operations may be unsafe");
83
84	static unsigned int delay_ms = 1000;
85	module_param(delay_ms, uint, 0644);
86	MODULE_PARM_DESC(delay_ms, "Milliseconds to delay the response to peer");
87
88	static unsigned long db_init = 0x7;
89	module_param(db_init, ulong, 0644);
90	MODULE_PARM_DESC(delay_ms, "Initial doorbell bits to ring on the peer");
91
92	struct pp_ctx {
93	struct ntb_dev *ntb;
94	u64 db_bits;
95	/* synchronize access to db_bits by ping and pong */
96	spinlock_t db_lock;
97	struct timer_list db_timer;
98	unsigned long db_delay;
99	};
100
101	static void pp_ping(unsigned long ctx)
102	{
103	struct pp_ctx pp = (void )ctx;
104	unsigned long irqflags;
105	u64 db_bits, db_mask;
106	u32 spad_rd, spad_wr;
107
108	spin_lock_irqsave(&pp->db_lock, irqflags);
109	{
110	db_mask = ntb_db_valid_mask(pp->ntb);
111	db_bits = ntb_db_read(pp->ntb);
112
113	if (db_bits) {
114	dev_dbg(&pp->ntb->dev,
115	"Masked pongs %#llx\n",
116	db_bits);
117	ntb_db_clear(pp->ntb, db_bits);
118	}
119
120	db_bits = ((pp->db_bits \| db_bits) << 1) & db_mask;
121
122	if (!db_bits)
123	db_bits = db_init;
124
125	spad_rd = ntb_spad_read(pp->ntb, 0);
126	spad_wr = spad_rd + 1;
127
128	dev_dbg(&pp->ntb->dev,
129	"Ping bits %#llx read %#x write %#x\n",
130	db_bits, spad_rd, spad_wr);
131
132	ntb_peer_spad_write(pp->ntb, 0, spad_wr);
133	ntb_peer_db_set(pp->ntb, db_bits);
134	ntb_db_clear_mask(pp->ntb, db_mask);
135
136	pp->db_bits = 0;
137	}
138	spin_unlock_irqrestore(&pp->db_lock, irqflags);
139	}
140
141	static void pp_link_event(void *ctx)
142	{
143	struct pp_ctx *pp = ctx;
144
145	if (ntb_link_is_up(pp->ntb, NULL, NULL) == 1) {
146	dev_dbg(&pp->ntb->dev, "link is up\n");
147	pp_ping((unsigned long)pp);
148	} else {
149	dev_dbg(&pp->ntb->dev, "link is down\n");
150	del_timer(&pp->db_timer);
151	}
152	}
153
154	static void pp_db_event(void *ctx, int vec)
155	{
156	struct pp_ctx *pp = ctx;
157	u64 db_bits, db_mask;
158	unsigned long irqflags;
159
160	spin_lock_irqsave(&pp->db_lock, irqflags);
161	{
162	db_mask = ntb_db_vector_mask(pp->ntb, vec);
163	db_bits = db_mask & ntb_db_read(pp->ntb);
164	ntb_db_set_mask(pp->ntb, db_mask);
165	ntb_db_clear(pp->ntb, db_bits);
166
167	pp->db_bits \|= db_bits;
168
169	mod_timer(&pp->db_timer, jiffies + pp->db_delay);
170
171	dev_dbg(&pp->ntb->dev,
172	"Pong vec %d bits %#llx\n",
173	vec, db_bits);
174	}
175	spin_unlock_irqrestore(&pp->db_lock, irqflags);
176	}
177
178	static const struct ntb_ctx_ops pp_ops = {
179	.link_event = pp_link_event,
180	.db_event = pp_db_event,
181	};
182
183	static int pp_probe(struct ntb_client *client,
184	struct ntb_dev *ntb)
185	{
186	struct pp_ctx *pp;
187	int rc;
188
189	if (ntb_db_is_unsafe(ntb)) {
190	dev_dbg(&ntb->dev, "doorbell is unsafe\n");
191	if (!unsafe) {
192	rc = -EINVAL;
193	goto err_pp;
194	}
195	}
196
197	if (ntb_spad_is_unsafe(ntb)) {
198	dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
199	if (!unsafe) {
200	rc = -EINVAL;
201	goto err_pp;
202	}
203	}
204
205	pp = kmalloc(sizeof(*pp), GFP_KERNEL);
206	if (!pp) {
207	rc = -ENOMEM;
208	goto err_pp;
209	}
210
211	pp->ntb = ntb;
212	pp->db_bits = 0;
213	spin_lock_init(&pp->db_lock);
214	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
215	pp->db_delay = msecs_to_jiffies(delay_ms);
216
217	rc = ntb_set_ctx(ntb, pp, &pp_ops);
218	if (rc)
219	goto err_ctx;
220
221	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
222	ntb_link_event(ntb);
223
224	return 0;
225
226	err_ctx:
227	kfree(pp);
228	err_pp:
229	return rc;
230	}
231
232	static void pp_remove(struct ntb_client *client,
233	struct ntb_dev *ntb)
234	{
235	struct pp_ctx *pp = ntb->ctx;
236
237	ntb_clear_ctx(ntb);
238	del_timer_sync(&pp->db_timer);
239	ntb_link_disable(ntb);
240
241	kfree(pp);
242	}
243
244	static struct ntb_client pp_client = {
245	.ops = {
246	.probe = pp_probe,
247	.remove = pp_remove,
248	},
249	};
250	module_ntb_client(pp_client);