On Fri, Jun 09, 2023 at 04:01:46AM -0700, Selvin Xavier wrote:
> From: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx>
>
> This interface will be used if the driver has not enabled interrupt
> and/or interrupt is disabled for a short period of time.
> Completion is not possible from interrupt so this interface does
> self-polling.
>
> Signed-off-by: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx>
> Signed-off-by: Selvin Xavier <selvin.xavier@xxxxxxxxxxxx>
> ---
> drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 44 +++++++++++++++++++++++++++++-
> drivers/infiniband/hw/bnxt_re/qplib_rcfw.h | 1 +
> 2 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> index 15f6793..3215f8a 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
> @@ -260,6 +260,44 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw,
> return 0;
> }
>
> +/**
> + * __poll_for_resp - self poll completion for rcfw command
> + * @rcfw - rcfw channel instance of rdev
> + * @cookie - cookie to track the command
> + * @opcode - rcfw submitted for given opcode
> + *
> + * It works same as __wait_for_resp except this function will
> + * do self polling in sort interval since interrupt is disabled.
> + * This function can not be called from non-sleepable context.
> + *
> + * Returns:
> + * -ETIMEOUT if command is not completed in specific time interval.
> + * 0 if command is completed by firmware.
> + */
> +static int __poll_for_resp(struct bnxt_qplib_rcfw *rcfw, u16 cookie,
> + u8 opcode)
> +{
> + struct bnxt_qplib_cmdq_ctx *cmdq = &rcfw->cmdq;
> + unsigned long issue_time;
> + u16 cbit;
> +
> + cbit = cookie % rcfw->cmdq_depth;
> + issue_time = jiffies;
> +
> + do {
> + if (test_bit(ERR_DEVICE_DETACHED, &cmdq->flags))
> + return bnxt_qplib_map_rc(opcode);
> +
> + usleep_range(1000, 1001);
> +
> + bnxt_qplib_service_creq(&rcfw->creq.creq_tasklet);
> + if (!test_bit(cbit, cmdq->cmdq_bitmap))
> + return 0;
> + if (jiffies_to_msecs(jiffies - issue_time) > 10000)
> + return -ETIMEDOUT;
> + } while (true);
> +};
> +
> static int __send_message_basic_sanity(struct bnxt_qplib_rcfw *rcfw,
> struct bnxt_qplib_cmdqmsg *msg)
> {
> @@ -328,8 +366,10 @@ static int __bnxt_qplib_rcfw_send_message(struct bnxt_qplib_rcfw *rcfw,
>
> if (msg->block)
> rc = __block_for_resp(rcfw, cookie, opcode);
> - else
> + else if (atomic_read(&rcfw->rcfw_intr_enabled))
Why atomic_t? It doesn't eliminate the need of locking and if locking
exists, you don't need atomic_t.
> rc = __wait_for_resp(rcfw, cookie, opcode);
> + else
> + rc = __poll_for_resp(rcfw, cookie, opcode);
> if (rc) {
> /* timed out */
> dev_err(&rcfw->pdev->dev, "cmdq[%#x]=%#x timedout (%d)msec\n",
> @@ -796,6 +836,7 @@ void bnxt_qplib_rcfw_stop_irq(struct bnxt_qplib_rcfw *rcfw, bool kill)
> kfree(creq->irq_name);
> creq->irq_name = NULL;
> creq->requested = false;
> + atomic_set(&rcfw->rcfw_intr_enabled, 0);
> }
>
> void bnxt_qplib_disable_rcfw_channel(struct bnxt_qplib_rcfw *rcfw)
> @@ -857,6 +898,7 @@ int bnxt_qplib_rcfw_start_irq(struct bnxt_qplib_rcfw *rcfw, int msix_vector,
> creq->requested = true;
>
> bnxt_qplib_ring_nq_db(&creq->creq_db.dbinfo, res->cctx, true);
> + atomic_inc(&rcfw->rcfw_intr_enabled);
>
> return 0;
> }
> diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> index b7bbbae..089e616 100644
> --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.h
> @@ -221,6 +221,7 @@ struct bnxt_qplib_rcfw {
> u64 oos_prev;
> u32 init_oos_stats;
> u32 cmdq_depth;
> + atomic_t rcfw_intr_enabled;
> struct semaphore rcfw_inflight;
> };
>
> --
> 2.5.5
>
