diff --git a/Documentation/ntb.txt b/Documentation/ntb.txt
index e5d1591478ca925ca71210c1f556b9113e5c85c2..b48249a7b6075bc9ae6649ba49ef2a17c77b8945 100644
--- a/Documentation/ntb.txt
+++ b/Documentation/ntb.txt
@@ -64,6 +64,38 @@ Module Parameters:
* dyndbg - It is suggested to specify dyndbg=+p when loading this module, and
then to observe debugging output on the console.
+### NTB Tool Test Client (ntb\_tool)
+
+The Tool test client serves for debugging, primarily, ntb hardware and drivers.
+The Tool provides access through debugfs for reading, setting, and clearing the
+NTB doorbell, and reading and writing scratchpads.
+
+The Tool does not currently have any module parameters.
+
+Debugfs Files:
+
+* *debugfs*/ntb\_tool/*hw*/ - A directory in debugfs will be created for each
+ NTB device probed by the tool. This directory is shortened to *hw*
+ below.
+* *hw*/db - This file is used to read, set, and clear the local doorbell. Not
+ all operations may be supported by all hardware. To read the doorbell,
+ read the file. To set the doorbell, write `s` followed by the bits to
+ set (eg: `echo 's 0x0101' > db`). To clear the doorbell, write `c`
+ followed by the bits to clear.
+* *hw*/mask - This file is used to read, set, and clear the local doorbell mask.
+ See *db* for details.
+* *hw*/peer\_db - This file is used to read, set, and clear the peer doorbell.
+ See *db* for details.
+* *hw*/peer\_mask - This file is used to read, set, and clear the peer doorbell
+ mask. See *db* for details.
+* *hw*/spad - This file is used to read and write local scratchpads. To read
+ the values of all scratchpads, read the file. To write values, write a
+ series of pairs of scratchpad number and value
+ (eg: `echo '4 0x123 7 0xabc' > spad`
+ # to set scratchpads `4` and `7` to `0x123` and `0xabc`, respectively).
+* *hw*/peer\_spad - This file is used to read and write peer scratchpads. See
+ *spad* for details.
+
## NTB Hardware Drivers
NTB hardware drivers should register devices with the NTB core driver. After
diff --git a/drivers/ntb/test/Kconfig b/drivers/ntb/test/Kconfig
index 72d255d220c818b39ab91a7cf415c790357b2fee..01852f98a843db8b9d04e4a9e5e115bce756a4b0 100644
--- a/drivers/ntb/test/Kconfig
+++ b/drivers/ntb/test/Kconfig
@@ -6,3 +6,14 @@ config NTB_PINGPONG
your ntb hardware and drivers are functioning at a basic level.
If unsure, say N.
+
+config NTB_TOOL
+ tristate "NTB Debugging Tool Test Client"
+ help
+ This is a simple debugging driver that enables the doorbell and
+ scratchpad registers to be read and written from the debugfs. This
+ enables more complicated debugging to be scripted from user space.
+ This driver may be used to test that your ntb hardware and drivers are
+ functioning at a basic level.
+
+ If unsure, say N.
diff --git a/drivers/ntb/test/Makefile b/drivers/ntb/test/Makefile
index b32309307771686ea624637adc8d3d00e0e6bea6..0ea32a324b6ca206a6f9beeaa4b86c75f0cab3e1 100644
--- a/drivers/ntb/test/Makefile
+++ b/drivers/ntb/test/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_NTB_PINGPONG) += ntb_pingpong.o
+obj-$(CONFIG_NTB_TOOL) += ntb_tool.o
diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
new file mode 100644
index 0000000000000000000000000000000000000000..6f5dc6ca673d37a1ed226b7cddbc22bd6cc51da0
--- /dev/null
+++ b/drivers/ntb/test/ntb_tool.c
@@ -0,0 +1,556 @@
+/*
+ * 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 Debugging Tool Linux driver
+ *
+ * Contact Information:
+ * Allen Hubbe <Allen.Hubbe@emc.com>
+ */
+
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_tool/0000:00:03.0'
+ *
+ * Eg: check if clearing the doorbell mask generates an interrupt.
+ *
+ * # Set the doorbell mask
+ * root@self# echo 's 1' > $DBG_DIR/mask
+ *
+ * # Ring the doorbell from the peer
+ * root@peer# echo 's 1' > $DBG_DIR/peer_db
+ *
+ * # Clear the doorbell mask
+ * root@self# echo 'c 1' > $DBG_DIR/mask
+ *
+ * Observe debugging output in dmesg or your console. You should see a
+ * doorbell event triggered by clearing the mask. If not, this may indicate an
+ * issue with the hardware that needs to be worked around in the driver.
+ *
+ * Eg: read and write scratchpad registers
+ *
+ * root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad
+ *
+ * root@self# cat $DBG_DIR/spad
+ *
+ * Observe that spad 0 and 1 have the values set by the peer.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include <linux/ntb.h>
+
+#define DRIVER_NAME "ntb_tool"
+#define DRIVER_DESCRIPTION "PCIe NTB Debugging Tool"
+
+#define DRIVER_LICENSE "Dual BSD/GPL"
+#define DRIVER_VERSION "1.0"
+#define DRIVER_RELDATE "22 April 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 struct dentry *tool_dbgfs;
+
+struct tool_ctx {
+ struct ntb_dev *ntb;
+ struct dentry *dbgfs;
+};
+
+#define SPAD_FNAME_SIZE 0x10
+#define INT_PTR(x) ((void *)(unsigned long)x)
+#define PTR_INT(x) ((int)(unsigned long)x)
+
+#define TOOL_FOPS_RDWR(__name, __read, __write) \
+ const struct file_operations __name = { \
+ .owner = THIS_MODULE, \
+ .open = simple_open, \
+ .read = __read, \
+ .write = __write, \
+ }
+
+static void tool_link_event(void *ctx)
+{
+ struct tool_ctx *tc = ctx;
+ enum ntb_speed speed;
+ enum ntb_width width;
+ int up;
+
+ up = ntb_link_is_up(tc->ntb, &speed, &width);
+
+ dev_dbg(&tc->ntb->dev, "link is %s speed %d width %d\n",
+ up ? "up" : "down", speed, width);
+}
+
+static void tool_db_event(void *ctx, int vec)
+{
+ struct tool_ctx *tc = ctx;
+ u64 db_bits, db_mask;
+
+ db_mask = ntb_db_vector_mask(tc->ntb, vec);
+ db_bits = ntb_db_read(tc->ntb);
+
+ dev_dbg(&tc->ntb->dev, "doorbell vec %d mask %#llx bits %#llx\n",
+ vec, db_mask, db_bits);
+}
+
+static const struct ntb_ctx_ops tool_ops = {
+ .link_event = tool_link_event,
+ .db_event = tool_db_event,
+};
+
+static ssize_t tool_dbfn_read(struct tool_ctx *tc, char __user *ubuf,
+ size_t size, loff_t *offp,
+ u64 (*db_read_fn)(struct ntb_dev *))
+{
+ size_t buf_size;
+ char *buf;
+ ssize_t pos, rc;
+
+ if (!db_read_fn)
+ return -EINVAL;
+
+ buf_size = min_t(size_t, size, 0x20);
+
+ buf = kmalloc(buf_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ pos = scnprintf(buf, buf_size, "%#llx\n",
+ db_read_fn(tc->ntb));
+
+ rc = simple_read_from_buffer(ubuf, size, offp, buf, pos);
+
+ kfree(buf);
+
+ return rc;
+}
+
+static ssize_t tool_dbfn_write(struct tool_ctx *tc,
+ const char __user *ubuf,
+ size_t size, loff_t *offp,
+ int (*db_set_fn)(struct ntb_dev *, u64),
+ int (*db_clear_fn)(struct ntb_dev *, u64))
+{
+ u64 db_bits;
+ char *buf, cmd;
+ ssize_t rc;
+ int n;
+
+ buf = kmalloc(size + 1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ rc = simple_write_to_buffer(buf, size, offp, ubuf, size);
+ if (rc < 0) {
+ kfree(buf);
+ return rc;
+ }
+
+ buf[size] = 0;
+
+ n = sscanf(buf, "%c %lli", &cmd, &db_bits);
+
+ kfree(buf);
+
+ if (n != 2) {
+ rc = -EINVAL;
+ } else if (cmd == 's') {
+ if (!db_set_fn)
+ rc = -EINVAL;
+ else
+ rc = db_set_fn(tc->ntb, db_bits);
+ } else if (cmd == 'c') {
+ if (!db_clear_fn)
+ rc = -EINVAL;
+ else
+ rc = db_clear_fn(tc->ntb, db_bits);
+ } else {
+ rc = -EINVAL;
+ }
+
+ return rc ? : size;
+}
+
+static ssize_t tool_spadfn_read(struct tool_ctx *tc, char __user *ubuf,
+ size_t size, loff_t *offp,
+ u32 (*spad_read_fn)(struct ntb_dev *, int))
+{
+ size_t buf_size;
+ char *buf;
+ ssize_t pos, rc;
+ int i, spad_count;
+
+ if (!spad_read_fn)
+ return -EINVAL;
+
+ buf_size = min_t(size_t, size, 0x100);
+
+ buf = kmalloc(buf_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ pos = 0;
+
+ spad_count = ntb_spad_count(tc->ntb);
+ for (i = 0; i < spad_count; ++i) {
+ pos += scnprintf(buf + pos, buf_size - pos, "%d\t%#x\n",
+ i, spad_read_fn(tc->ntb, i));
+ }
+
+ rc = simple_read_from_buffer(ubuf, size, offp, buf, pos);
+
+ kfree(buf);
+
+ return rc;
+}
+
+static ssize_t tool_spadfn_write(struct tool_ctx *tc,
+ const char __user *ubuf,
+ size_t size, loff_t *offp,
+ int (*spad_write_fn)(struct ntb_dev *,
+ int, u32))
+{
+ int spad_idx;
+ u32 spad_val;
+ char *buf;
+ int pos, n;
+ ssize_t rc;
+
+ if (!spad_write_fn) {
+ dev_dbg(&tc->ntb->dev, "no spad write fn\n");
+ return -EINVAL;
+ }
+
+ buf = kmalloc(size + 1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ rc = simple_write_to_buffer(buf, size, offp, ubuf, size);
+ if (rc < 0) {
+ kfree(buf);
+ return rc;
+ }
+
+ buf[size] = 0;
+
+ n = sscanf(buf, "%d %i%n", &spad_idx, &spad_val, &pos);
+ while (n == 2) {
+ rc = spad_write_fn(tc->ntb, spad_idx, spad_val);
+ if (rc)
+ break;
+
+ n = sscanf(buf + pos, "%d %i%n", &spad_idx, &spad_val, &pos);
+ }
+
+ if (n < 0)
+ rc = n;
+
+ kfree(buf);
+
+ return rc ? : size;
+}
+
+static ssize_t tool_db_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->db_read);
+}
+
+static ssize_t tool_db_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->db_set,
+ tc->ntb->ops->db_clear);
+}
+
+static TOOL_FOPS_RDWR(tool_db_fops,
+ tool_db_read,
+ tool_db_write);
+
+static ssize_t tool_mask_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->db_read_mask);
+}
+
+static ssize_t tool_mask_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->db_set_mask,
+ tc->ntb->ops->db_clear_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_mask_fops,
+ tool_mask_read,
+ tool_mask_write);
+
+static ssize_t tool_peer_db_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_db_read);
+}
+
+static ssize_t tool_peer_db_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_db_set,
+ tc->ntb->ops->peer_db_clear);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_db_fops,
+ tool_peer_db_read,
+ tool_peer_db_write);
+
+static ssize_t tool_peer_mask_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_db_read_mask);
+}
+
+static ssize_t tool_peer_mask_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_dbfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_db_set_mask,
+ tc->ntb->ops->peer_db_clear_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_mask_fops,
+ tool_peer_mask_read,
+ tool_peer_mask_write);
+
+static ssize_t tool_spad_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_spadfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->spad_read);
+}
+
+static ssize_t tool_spad_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_spadfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->spad_write);
+}
+
+static TOOL_FOPS_RDWR(tool_spad_fops,
+ tool_spad_read,
+ tool_spad_write);
+
+static ssize_t tool_peer_spad_read(struct file *filep, char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_spadfn_read(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_spad_read);
+}
+
+static ssize_t tool_peer_spad_write(struct file *filep, const char __user *ubuf,
+ size_t size, loff_t *offp)
+{
+ struct tool_ctx *tc = filep->private_data;
+
+ return tool_spadfn_write(tc, ubuf, size, offp,
+ tc->ntb->ops->peer_spad_write);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_spad_fops,
+ tool_peer_spad_read,
+ tool_peer_spad_write);
+
+static void tool_setup_dbgfs(struct tool_ctx *tc)
+{
+ /* This modules is useless without dbgfs... */
+ if (!tool_dbgfs) {
+ tc->dbgfs = NULL;
+ return;
+ }
+
+ tc->dbgfs = debugfs_create_dir(dev_name(&tc->ntb->dev),
+ tool_dbgfs);
+ if (!tc->dbgfs)
+ return;
+
+ debugfs_create_file("db", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_db_fops);
+
+ debugfs_create_file("mask", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_mask_fops);
+
+ debugfs_create_file("peer_db", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_peer_db_fops);
+
+ debugfs_create_file("peer_mask", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_peer_mask_fops);
+
+ debugfs_create_file("spad", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_spad_fops);
+
+ debugfs_create_file("peer_spad", S_IRUSR | S_IWUSR, tc->dbgfs,
+ tc, &tool_peer_spad_fops);
+}
+
+static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
+{
+ struct tool_ctx *tc;
+ int rc;
+
+ if (ntb_db_is_unsafe(ntb))
+ dev_dbg(&ntb->dev, "doorbell is unsafe\n");
+
+ if (ntb_spad_is_unsafe(ntb))
+ dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
+
+ tc = kmalloc(sizeof(*tc), GFP_KERNEL);
+ if (!tc) {
+ rc = -ENOMEM;
+ goto err_tc;
+ }
+
+ tc->ntb = ntb;
+
+ tool_setup_dbgfs(tc);
+
+ rc = ntb_set_ctx(ntb, tc, &tool_ops);
+ if (rc)
+ goto err_ctx;
+
+ ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+ ntb_link_event(ntb);
+
+ return 0;
+
+err_ctx:
+ debugfs_remove_recursive(tc->dbgfs);
+ kfree(tc);
+err_tc:
+ return rc;
+}
+
+static void tool_remove(struct ntb_client *self, struct ntb_dev *ntb)
+{
+ struct tool_ctx *tc = ntb->ctx;
+
+ ntb_clear_ctx(ntb);
+ ntb_link_disable(ntb);
+
+ debugfs_remove_recursive(tc->dbgfs);
+ kfree(tc);
+}
+
+static struct ntb_client tool_client = {
+ .ops = {
+ .probe = tool_probe,
+ .remove = tool_remove,
+ },
+};
+
+static int __init tool_init(void)
+{
+ int rc;
+
+ if (debugfs_initialized())
+ tool_dbgfs = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+ rc = ntb_register_client(&tool_client);
+ if (rc)
+ goto err_client;
+
+ return 0;
+
+err_client:
+ debugfs_remove_recursive(tool_dbgfs);
+ return rc;
+}
+module_init(tool_init);
+
+static void __exit tool_exit(void)
+{
+ ntb_unregister_client(&tool_client);
+ debugfs_remove_recursive(tool_dbgfs);
+}
+module_exit(tool_exit);