meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0005-firmware-arm_scmi-Add-xfer_init_buffers-transport-op.patch

   1 From fddb9bcd706ed3bb262f4f37707616dd06c7a4cc Mon Sep 17 00:00:00 2001
   2 From: Igor Skalkin <igor.skalkin@opensynergy.com>
   3 Date: Thu, 5 Nov 2020 22:21:11 +0100
   4 Subject: [PATCH] firmware: arm_scmi: Add xfer_init_buffers transport op
   5
   6 The virtio transport in this patch series can be simplified by using the
   7 scmi_xfer tx/rx buffers for data exchange with the virtio device, and
   8 for saving the message state. But the virtio transport requires
   9 prepending a transport-specific header. Also, for data exchange using
  10 virtqueues, the tx and rx buffers should not overlap.
  11
  12 After the previous patch, this is the second and final step to enable
  13 the virtio transport to use the scmi_xfer buffers for data exchange.
  14
  15 Add an optional op through which the transport can allocate the tx/rx
  16 buffers along with room for the prepended transport-specific headers.
  17
  18 Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
  19 Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
  20 Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
  21 Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
  22 ---
  23  drivers/firmware/arm_scmi/common.h |  3 +++
  24  drivers/firmware/arm_scmi/driver.c | 21 +++++++++++++++------
  25  2 files changed, 18 insertions(+), 6 deletions(-)
  26
  27 diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
  28 index c998ec29018e..ae5db602e45d 100644
  29 --- a/drivers/firmware/arm_scmi/common.h
  30 +++ b/drivers/firmware/arm_scmi/common.h
  31 @@ -208,6 +208,7 @@ struct scmi_chan_info {
  32   * @get_max_msg: Optional callback to provide max_msg dynamically
  33   *     @max_msg: Maximum number of messages for the channel type (tx or rx)
  34   *             that can be pending simultaneously in the system
  35 + * @xfer_init_buffers: Callback to initialize buffers for scmi_xfer
  36   * @send_message: Callback to send a message
  37   * @mark_txdone: Callback to mark tx as done
  38   * @fetch_response: Callback to fetch response
  39 @@ -222,6 +223,8 @@ struct scmi_transport_ops {
  40         int (*chan_free)(int id, void *p, void *data);
  41         int (*get_max_msg)(bool tx, struct scmi_chan_info *base_cinfo,
  42                            int *max_msg);
  43 +       int (*xfer_init_buffers)(struct scmi_chan_info *cinfo,
  44 +                                struct scmi_xfer *xfer, int max_msg_size);
  45         int (*send_message)(struct scmi_chan_info *cinfo,
  46                             struct scmi_xfer *xfer);
  47         void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
  48 diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
  49 index 5baa23789a49..27dd43dcff5b 100644
  50 --- a/drivers/firmware/arm_scmi/driver.c
  51 +++ b/drivers/firmware/arm_scmi/driver.c
  52 @@ -640,12 +640,21 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo,
  53
  54         /* Pre-initialize the buffer pointer to pre-allocated buffers */
  55         for (i = 0, xfer = info->xfer_block; i < info->max_msg; i++, xfer++) {
  56 -               xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size,
  57 -                                           GFP_KERNEL);
  58 -               if (!xfer->rx.buf)
  59 -                       return -ENOMEM;
  60 -
  61 -               xfer->tx.buf = xfer->rx.buf;
  62 +               if (desc->ops->xfer_init_buffers) {
  63 +                       int ret = desc->ops->xfer_init_buffers(
  64 +                               base_cinfo, xfer, desc->max_msg_size);
  65 +
  66 +                       if (ret)
  67 +                               return ret;
  68 +               } else {
  69 +                       xfer->rx.buf = devm_kcalloc(dev, sizeof(u8),
  70 +                                                   desc->max_msg_size,
  71 +                                                   GFP_KERNEL);
  72 +                       if (!xfer->rx.buf)
  73 +                               return -ENOMEM;
  74 +
  75 +                       xfer->tx.buf = xfer->rx.buf;
  76 +               }
  77                 init_completion(&xfer->done);
  78         }
  79