[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/debugfs.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(db_init, "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;
	struct dentry			*debugfs_node_dir;
	struct dentry			*debugfs_count;
	atomic_t			count;
};

static struct dentry *pp_debugfs_dir;

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);
		atomic_inc(&pp->count);
	}
	spin_unlock_irqrestore(&pp->db_lock, irqflags);
}

static int pp_debugfs_setup(struct pp_ctx *pp)
{
	struct pci_dev *pdev = pp->ntb->pdev;

	if (!pp_debugfs_dir)
		return -ENODEV;

	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
						  pp_debugfs_dir);
	if (!pp->debugfs_node_dir)
		return -ENODEV;

	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR | S_IWUSR,
						    pp->debugfs_node_dir,
						    &pp->count);
	if (!pp->debugfs_count)
		return -ENODEV;

	return 0;
}

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;
	atomic_set(&pp->count, 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;

	rc = pp_debugfs_setup(pp);
	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;

	debugfs_remove_recursive(pp->debugfs_node_dir);

	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,
	},
};

static int __init pp_init(void)
{
	int rc;

	if (debugfs_initialized())
		pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);

	rc = ntb_register_client(&pp_client);
	if (rc)
		goto err_client;

	return 0;

err_client:
	debugfs_remove_recursive(pp_debugfs_dir);
	return rc;
}
module_init(pp_init);

static void __exit pp_exit(void)
{
	ntb_unregister_client(&pp_client);
	debugfs_remove_recursive(pp_debugfs_dir);
}
module_exit(pp_exit);
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>
20572ee1	64	#include <linux/debugfs.h>
963de473 AH	65
	66	#include <linux/ntb.h>
	67
	68	#define DRIVER_NAME "ntb_pingpong"
	69	#define DRIVER_DESCRIPTION "PCIe NTB Simple Pingpong Client"
	70
	71	#define DRIVER_LICENSE "Dual BSD/GPL"
	72	#define DRIVER_VERSION "1.0"
	73	#define DRIVER_RELDATE "24 March 2015"
	74	#define DRIVER_AUTHOR "Allen Hubbe <Allen.Hubbe@emc.com>"
	75
	76	MODULE_LICENSE(DRIVER_LICENSE);
	77	MODULE_VERSION(DRIVER_VERSION);
	78	MODULE_AUTHOR(DRIVER_AUTHOR);
	79	MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
	80
	81	static unsigned int unsafe;
	82	module_param(unsafe, uint, 0644);
	83	MODULE_PARM_DESC(unsafe, "Run even though ntb operations may be unsafe");
	84
	85	static unsigned int delay_ms = 1000;
	86	module_param(delay_ms, uint, 0644);
	87	MODULE_PARM_DESC(delay_ms, "Milliseconds to delay the response to peer");
	88
	89	static unsigned long db_init = 0x7;
	90	module_param(db_init, ulong, 0644);
cedecbc5	91	MODULE_PARM_DESC(db_init, "Initial doorbell bits to ring on the peer");
963de473 AH	92
	93	struct pp_ctx {
	94	struct ntb_dev *ntb;
	95	u64 db_bits;
	96	/* synchronize access to db_bits by ping and pong */
	97	spinlock_t db_lock;
	98	struct timer_list db_timer;
	99	unsigned long db_delay;
20572ee1 LG	100	struct dentry *debugfs_node_dir;
	101	struct dentry *debugfs_count;
	102	atomic_t count;
963de473 AH	103	};
963de473 AH	104
20572ee1 LG	105	static struct dentry *pp_debugfs_dir;
20572ee1 LG	106
963de473 AH	107	static void pp_ping(unsigned long ctx)
	108	{
	109	struct pp_ctx pp = (void )ctx;
	110	unsigned long irqflags;
	111	u64 db_bits, db_mask;
	112	u32 spad_rd, spad_wr;
	113
	114	spin_lock_irqsave(&pp->db_lock, irqflags);
	115	{
	116	db_mask = ntb_db_valid_mask(pp->ntb);
	117	db_bits = ntb_db_read(pp->ntb);
	118
	119	if (db_bits) {
	120	dev_dbg(&pp->ntb->dev,
	121	"Masked pongs %#llx\n",
	122	db_bits);
	123	ntb_db_clear(pp->ntb, db_bits);
	124	}
	125
	126	db_bits = ((pp->db_bits \| db_bits) << 1) & db_mask;
	127
	128	if (!db_bits)
	129	db_bits = db_init;
	130
	131	spad_rd = ntb_spad_read(pp->ntb, 0);
	132	spad_wr = spad_rd + 1;
	133
	134	dev_dbg(&pp->ntb->dev,
	135	"Ping bits %#llx read %#x write %#x\n",
	136	db_bits, spad_rd, spad_wr);
	137
	138	ntb_peer_spad_write(pp->ntb, 0, spad_wr);
	139	ntb_peer_db_set(pp->ntb, db_bits);
	140	ntb_db_clear_mask(pp->ntb, db_mask);
	141
	142	pp->db_bits = 0;
	143	}
	144	spin_unlock_irqrestore(&pp->db_lock, irqflags);
	145	}
	146
	147	static void pp_link_event(void *ctx)
	148	{
	149	struct pp_ctx *pp = ctx;
	150
	151	if (ntb_link_is_up(pp->ntb, NULL, NULL) == 1) {
	152	dev_dbg(&pp->ntb->dev, "link is up\n");
	153	pp_ping((unsigned long)pp);
	154	} else {
	155	dev_dbg(&pp->ntb->dev, "link is down\n");
	156	del_timer(&pp->db_timer);
	157	}
	158	}
	159
	160	static void pp_db_event(void *ctx, int vec)
	161	{
	162	struct pp_ctx *pp = ctx;
	163	u64 db_bits, db_mask;
	164	unsigned long irqflags;
	165
	166	spin_lock_irqsave(&pp->db_lock, irqflags);
	167	{
	168	db_mask = ntb_db_vector_mask(pp->ntb, vec);
	169	db_bits = db_mask & ntb_db_read(pp->ntb);
	170	ntb_db_set_mask(pp->ntb, db_mask);
171	ntb_db_clear(pp->ntb, db_bits);
172
173	pp->db_bits \|= db_bits;
174
175	mod_timer(&pp->db_timer, jiffies + pp->db_delay);
176
177	dev_dbg(&pp->ntb->dev,
178	"Pong vec %d bits %#llx\n",
179	vec, db_bits);
20572ee1	180	atomic_inc(&pp->count);
963de473 AH	181	}
	182	spin_unlock_irqrestore(&pp->db_lock, irqflags);
	183	}
	184
20572ee1 LG	185	static int pp_debugfs_setup(struct pp_ctx *pp)
	186	{
	187	struct pci_dev *pdev = pp->ntb->pdev;
	188
	189	if (!pp_debugfs_dir)
	190	return -ENODEV;
	191
	192	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
	193	pp_debugfs_dir);
	194	if (!pp->debugfs_node_dir)
	195	return -ENODEV;
	196
	197	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR \| S_IWUSR,
	198	pp->debugfs_node_dir,
	199	&pp->count);
	200	if (!pp->debugfs_count)
	201	return -ENODEV;
	202
	203	return 0;
	204	}
	205
963de473 AH	206	static const struct ntb_ctx_ops pp_ops = {
	207	.link_event = pp_link_event,
	208	.db_event = pp_db_event,
	209	};
	210
	211	static int pp_probe(struct ntb_client *client,
	212	struct ntb_dev *ntb)
	213	{
	214	struct pp_ctx *pp;
	215	int rc;
	216
	217	if (ntb_db_is_unsafe(ntb)) {
	218	dev_dbg(&ntb->dev, "doorbell is unsafe\n");
	219	if (!unsafe) {
	220	rc = -EINVAL;
	221	goto err_pp;
	222	}
	223	}
	224
	225	if (ntb_spad_is_unsafe(ntb)) {
	226	dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
	227	if (!unsafe) {
	228	rc = -EINVAL;
	229	goto err_pp;
	230	}
	231	}
	232
	233	pp = kmalloc(sizeof(*pp), GFP_KERNEL);
	234	if (!pp) {
	235	rc = -ENOMEM;
	236	goto err_pp;
	237	}
	238
	239	pp->ntb = ntb;
	240	pp->db_bits = 0;
20572ee1	241	atomic_set(&pp->count, 0);
963de473 AH	242	spin_lock_init(&pp->db_lock);
	243	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
	244	pp->db_delay = msecs_to_jiffies(delay_ms);
	245
	246	rc = ntb_set_ctx(ntb, pp, &pp_ops);
	247	if (rc)
	248	goto err_ctx;
	249
20572ee1 LG	250	rc = pp_debugfs_setup(pp);
	251	if (rc)
	252	goto err_ctx;
	253
963de473 AH	254	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
	255	ntb_link_event(ntb);
	256
	257	return 0;
	258
	259	err_ctx:
	260	kfree(pp);
	261	err_pp:
	262	return rc;
	263	}
	264
	265	static void pp_remove(struct ntb_client *client,
	266	struct ntb_dev *ntb)
	267	{
	268	struct pp_ctx *pp = ntb->ctx;
	269
20572ee1 LG	270	debugfs_remove_recursive(pp->debugfs_node_dir);
20572ee1 LG	271
963de473 AH	272	ntb_clear_ctx(ntb);
	273	del_timer_sync(&pp->db_timer);
	274	ntb_link_disable(ntb);
	275
	276	kfree(pp);
	277	}
	278
	279	static struct ntb_client pp_client = {
	280	.ops = {
	281	.probe = pp_probe,
	282	.remove = pp_remove,
	283	},
	284	};
20572ee1 LG	285
	286	static int __init pp_init(void)
	287	{
	288	int rc;
	289
	290	if (debugfs_initialized())
	291	pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
	292
	293	rc = ntb_register_client(&pp_client);
	294	if (rc)
	295	goto err_client;
	296
	297	return 0;
	298
	299	err_client:
	300	debugfs_remove_recursive(pp_debugfs_dir);
	301	return rc;
	302	}
	303	module_init(pp_init);
	304
	305	static void __exit pp_exit(void)
	306	{
	307	ntb_unregister_client(&pp_client);
	308	debugfs_remove_recursive(pp_debugfs_dir);
	309	}
	310	module_exit(pp_exit);