diff options
Diffstat (limited to 'drivers/ntb/test/ntb_pingpong.c')
| -rw-r--r-- | drivers/ntb/test/ntb_pingpong.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c new file mode 100644 index 000000000000..fe1600566981 --- /dev/null +++ b/drivers/ntb/test/ntb_pingpong.c @@ -0,0 +1,250 @@ +/* + * 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); |