Minor question/suggestion inline. (sorry for missing it till now). Yuval On Sat, Sep 24, 2016 at 04:21:32PM -0700, Adit Ranadive wrote: > This patch enables posting Verb requests and receiving responses to/from > the backend PVRDMA emulation layer. > > Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx> > Reviewed-by: Jorgen Hansen <jhansen@xxxxxxxxxx> > Reviewed-by: George Zhang <georgezhang@xxxxxxxxxx> > Reviewed-by: Aditya Sarwade <asarwade@xxxxxxxxxx> > Reviewed-by: Bryan Tan <bryantan@xxxxxxxxxx> > Signed-off-by: Adit Ranadive <aditr@xxxxxxxxxx> > --- > Changes v4->v5: > - Moved the timeout to pvrdma_cmd_recv. > - Added additional response code parameter to pvrdma_cmd_post. > > Changes v3->v4: > - Removed the min check and added a BUILD_BUG_ON check for size. > > Changes v2->v3: > - Converted pvrdma_cmd_recv to inline. > - Added a min check in the memcpy to cmd_slot. > - Removed the boolean from pvrdma_cmd_post. > --- > drivers/infiniband/hw/pvrdma/pvrdma_cmd.c | 117 ++++++++++++++++++++++++++++++ > 1 file changed, 117 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..21f1af8 > --- /dev/null > +++ b/drivers/infiniband/hw/pvrdma/pvrdma_cmd.c > @@ -0,0 +1,117 @@ > +/* > + * 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 inline int pvrdma_cmd_recv(struct pvrdma_dev *dev, > + union pvrdma_cmd_resp *resp, > + unsigned resp_code) > +{ > + int err; > + > + dev_dbg(&dev->pdev->dev, "receive response from device\n"); > + > + err = wait_for_completion_interruptible_timeout(&dev->cmd_done, > + msecs_to_jiffies(PVRDMA_CMD_TIMEOUT)); > + if (err == 0 || err == -ERESTARTSYS) { > + dev_warn(&dev->pdev->dev, > + "completion timeout or interrupted\n"); > + return -ETIMEDOUT; > + } > + > + spin_lock(&dev->cmd_lock); > + memcpy(resp, dev->resp_slot, sizeof(*resp)); > + spin_unlock(&dev->cmd_lock); > + > + if (resp->hdr.ack != resp_code) { > + dev_warn(&dev->pdev->dev, > + "unknown response %#x expected %#x\n", > + resp->hdr.ack, resp_code); > + return -EFAULT; > + } > + > + return 0; > +} > + > +int > +pvrdma_cmd_post(struct pvrdma_dev *dev, union pvrdma_cmd_req *req, > + union pvrdma_cmd_resp *resp, unsigned resp_code) > +{ > + int err; > + > + dev_dbg(&dev->pdev->dev, "post request to device\n"); > + > + /* Serializiation */ > + down(&dev->cmd_sema); > + > + BUILD_BUG_ON(sizeof(union pvrdma_cmd_req) != > + sizeof(struct pvrdma_cmd_modify_qp)); > + > + 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 (resp != NULL) > + err = pvrdma_cmd_recv(dev, resp, resp_code); > + } else { > + dev_warn(&dev->pdev->dev, "failed to write request %d\n", err); > + } Please note that callers checks if err<0 while here err!=0 considered as error. Looking at similar code in pvrdma_pci_probe i can see that function "translates" this error to -EINVAL. Suggesting to do the same here (although -EINVAL is not a good choice, if device can be more friendly with the return code then we can propagate it up or just print a suitable error i.e. EAGAIN or ENOMEM otherwise EFAULT should be sufficient). > + > + up(&dev->cmd_sema); > + > + return err; > +} > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
