lkml.org 
[lkml]   [2022]   [Jul]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH v2 24/25] usb: gadget: f_tcm: Check overlapped command
    If there's an overlapped command tag, cancel the command and respond
    with RC_OVERLAPPED_TAG to host.

    Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
    ---
    Changes in v2:
    - New patch. It was part of TASK MANAGEMENT change.
    - Directly respond to host on overlapped tag instead of reporting to target
    core.

    drivers/usb/gadget/function/f_tcm.c | 75 ++++++++++++++++++++++++++++-
    1 file changed, 73 insertions(+), 2 deletions(-)

    diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
    index 8b99ee07df87..dfa3e7c043a3 100644
    --- a/drivers/usb/gadget/function/f_tcm.c
    +++ b/drivers/usb/gadget/function/f_tcm.c
    @@ -692,6 +692,15 @@ static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req)
    break;

    case UASP_QUEUE_COMMAND:
    + /*
    + * Overlapped command detected and cancelled.
    + * So send overlapped attempted status.
    + */
    + if (cmd->tmr_rsp == RC_OVERLAPPED_TAG &&
    + req->status == -ECONNRESET) {
    + uasp_send_tm_response(cmd);
    + return;
    + }

    stream->cmd = NULL;

    @@ -700,7 +709,8 @@ static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req)
    * bitmap index. This is for the cases where f_tcm handles
    * status response instead of the target core.
    */
    - if (cmd->tmr_rsp != RC_RESPONSE_UNKNOWN) {
    + if (cmd->tmr_rsp != RC_OVERLAPPED_TAG &&
    + cmd->tmr_rsp != RC_RESPONSE_UNKNOWN) {
    struct se_session *se_sess;

    se_sess = fu->tpg->tpg_nexus->tvn_se_sess;
    @@ -1080,6 +1090,14 @@ static void usbg_data_write_cmpl(struct usb_ep *ep, struct usb_request *req)

    cleanup:
    target_put_sess_cmd(se_cmd);
    +
    + /* Command was aborted due to overlapped tag */
    + if (cmd->state == UASP_QUEUE_COMMAND &&
    + cmd->tmr_rsp == RC_OVERLAPPED_TAG) {
    + uasp_send_tm_response(cmd);
    + return;
    + }
    +
    transport_send_check_condition_and_sense(se_cmd,
    TCM_CHECK_CONDITION_ABORT_CMD, 0);
    }
    @@ -1148,9 +1166,10 @@ static int usbg_send_read_response(struct se_cmd *se_cmd)
    return uasp_send_read_response(cmd);
    }

    +static void usbg_aborted_task(struct se_cmd *se_cmd);
    +
    static void usbg_submit_tmr(struct usbg_cmd *cmd)
    {
    - struct usbg_cmd *cmd = container_of(work, struct usbg_cmd, work);
    struct se_session *se_sess;
    struct se_cmd *se_cmd;
    int flags = TARGET_SCF_ACK_KREF;
    @@ -1214,6 +1233,51 @@ static void usbg_cmd_work(struct work_struct *work)
    return;

    skip:
    + if (cmd->tmr_rsp == RC_OVERLAPPED_TAG) {
    + struct se_session *se_sess;
    + struct uas_stream *stream;
    +
    + se_sess = cmd->fu->tpg->tpg_nexus->tvn_se_sess;
    + stream = uasp_get_stream_by_tag(cmd->fu, cmd->tag);
    +
    + /*
    + * There's no guarantee of a matching completion order between
    + * different endpoints. i.e. The device may receive a new (CDB)
    + * command request completion of the command endpoint before it
    + * gets notified of the previous command status completion from
    + * a status endpoint. The driver still needs to detect
    + * misbehaving host and respond with an overlap command tag. To
    + * prevent false overlapped tag failure, give the active and
    + * matching stream id a short time (1ms) to complete before
    + * respond with overlapped command failure.
    + */
    + msleep(1);
    +
    + /* If the stream is completed, retry the command. */
    + if (!stream->cmd) {
    + usbg_submit_command(cmd->fu, cmd->req);
    + return;
    + }
    +
    + /*
    + * The command isn't submitted to the target core, so we're safe
    + * to remove the bitmap index from the session tag pool.
    + */
    + sbitmap_queue_clear(&se_sess->sess_tag_pool,
    + cmd->se_cmd.map_tag,
    + cmd->se_cmd.map_cpu);
    +
    + /*
    + * Overlap command tag detected. Cancel any pending transfer of
    + * the command submitted to target core.
    + */
    + stream->cmd->tmr_rsp = RC_OVERLAPPED_TAG;
    + usbg_aborted_task(&stream->cmd->se_cmd);
    +
    + /* Send the response after the transfer is aborted. */
    + return;
    + }
    +
    uasp_send_tm_response(cmd);
    }

    @@ -1282,6 +1346,13 @@ static int usbg_submit_command(struct f_uas *fu, struct usb_request *req)
    goto skip;
    }

    + stream = uasp_get_stream_by_tag(fu, scsi_tag);
    + if (stream->cmd) {
    + pr_err("Command tag %d overlapped\n", scsi_tag);
    + cmd->tmr_rsp = RC_OVERLAPPED_TAG;
    + goto skip;
    + }
    +
    stream->cmd = cmd;

    if (iu->iu_id == IU_ID_TASK_MGMT) {
    --
    2.28.0
    \
     
     \ /
      Last update: 2022-07-19 03:54    [W:4.043 / U:0.344 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site