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Release 4.14 drivers/ntb/test/ntb_pingpong.c

Directory: drivers/ntb/test
/*
 * 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");

/* Only two-ports NTB devices are supported */

#define PIDX		NTB_DEF_PEER_IDX


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, PIDX, 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); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe19999.00%150.00%
Serge Semin21.00%150.00%
Total201100.00%2100.00%


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); } }

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PersonTokensPropCommitsCommitProp
Allen Hubbe78100.00%1100.00%
Total78100.00%1100.00%


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); }

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PersonTokensPropCommitsCommitProp
Allen Hubbe12794.07%150.00%
Logan Gunthorpe85.93%150.00%
Total135100.00%2100.00%


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; }

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PersonTokensPropCommitsCommitProp
Logan Gunthorpe92100.00%1100.00%
Total92100.00%1100.00%

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_count(ntb) < 1) { dev_dbg(&ntb->dev, "no enough scratchpads\n"); 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; } } if (ntb_peer_port_count(ntb) != NTB_DEF_PEER_CNT) dev_warn(&ntb->dev, "multi-port NTB is unsupported\n"); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe21374.74%125.00%
Serge Semin4816.84%250.00%
Logan Gunthorpe248.42%125.00%
Total285100.00%4100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe4887.27%150.00%
Logan Gunthorpe712.73%150.00%
Total55100.00%2100.00%

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; }

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Logan Gunthorpe54100.00%1100.00%
Total54100.00%1100.00%

module_init(pp_init);
static void __exit pp_exit(void) { ntb_unregister_client(&pp_client); debugfs_remove_recursive(pp_debugfs_dir); }

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Logan Gunthorpe1680.00%150.00%
Allen Hubbe420.00%150.00%
Total20100.00%2100.00%

module_exit(pp_exit);

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PersonTokensPropCommitsCommitProp
Allen Hubbe87075.06%120.00%
Logan Gunthorpe23320.10%120.00%
Serge Semin554.75%240.00%
Wei Yongjun10.09%120.00%
Total1159100.00%5100.00%
Directory: drivers/ntb/test
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