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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/ntb/test/ntb_pingpong.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/ntb/test/ntb_pingpong.c')
-rw-r--r-- | drivers/ntb/test/ntb_pingpong.c | 433 |
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); |