[PATCH v1 02/15] IB/pvrdma: Add device command support

Adit Ranadive
2016-07-06T06:14:35Z

This patch enables posting Verb requests and receiving responses to/from
the backend PVRDMA emulation layer.

Reviewed-by: Jorgen Hansen <jhansen-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Reviewed-by: George Zhang <georgezhang-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Reviewed-by: Aditya Sarwade <asarwade-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Reviewed-by: Bryan Tan <bryantan-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Signed-off-by: Adit Ranadive <aditr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
---
drivers/infiniband/hw/pvrdma/pvrdma_cmd.c | 104 ++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)
create mode 100644 drivers/infiniband/hw/pvrdma/pvrdma_cmd.c

diff --git a/drivers/infiniband/hw/pvrdma/pvrdma_cmd.c b/drivers/infiniband/hw/pvrdma/pvrdma_cmd.c
new file mode 100644
index 0000000..c22debf
--- /dev/null
+++ b/drivers/infiniband/hw/pvrdma/pvrdma_cmd.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2012-2016 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of EITHER the GNU General Public License
+ * version 2 as published by the Free Software Foundation or the BSD
+ * 2-Clause License. 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 version 2 for more details at
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program available in the file COPYING in the main
+ * directory of this source tree.
+ *
+ * The BSD 2-Clause License
+ *
+ * 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
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * 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 HOLDER 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.
+ */
+
+#include <linux/list.h>
+
+#include "pvrdma.h"
+
+#define PVRDMA_CMD_TIMEOUT 10000 /* ms */
+
+static int pvrdma_cmd_recv(struct pvrdma_dev *dev, union pvrdma_cmd_resp *resp)
+{
+ dev_dbg(&dev->pdev->dev, "receive response from device\n");
+
+ spin_lock(&dev->cmd_lock);
+ memcpy(resp, dev->resp_slot, sizeof(*resp));
+ spin_unlock(&dev->cmd_lock);
+
+ return 0;
+}
+
+int
+pvrdma_cmd_post(struct pvrdma_dev *dev, union pvrdma_cmd_req *req,
+ bool expect_resp, union pvrdma_cmd_resp *resp)
+{
+ int err;
+
+ dev_dbg(&dev->pdev->dev, "post request to device\n");
+
+ /* Serializiation */
+ down(&dev->cmd_sema);
+
+ spin_lock(&dev->cmd_lock);
+ memcpy(dev->cmd_slot, req, sizeof(*req));
+ spin_unlock(&dev->cmd_lock);
+
+ init_completion(&dev->cmd_done);
+ pvrdma_write_reg(dev, PVRDMA_REG_REQUEST, 0);
+
+ /* Make sure the request is written before reading status. */
+ mb();
+ err = pvrdma_read_reg(dev, PVRDMA_REG_ERR);
+ if (err == 0) {
+ if (expect_resp) {
+ err = wait_for_completion_interruptible_timeout(
+ &dev->cmd_done,
+ msecs_to_jiffies(PVRDMA_CMD_TIMEOUT));
+ if (err == 0) {
+ dev_warn(&dev->pdev->dev,
+ "completion timeout\n");
+ err = -ETIMEDOUT;
+ } else {
+ err = pvrdma_cmd_recv(dev, resp);
+ }
+ }
+ } else {
+ dev_warn(&dev->pdev->dev, "failed to write request %d\n", err);
+ }
+
+ up(&dev->cmd_sema);
+
+ return err;