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- /*
- * 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 = -1, spad_data = -1;
- 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);
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