--- /dev/null
+/*
+ * 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);
Code Review / kvmfornfv.git / blobdiff