On 23/11/2022 21:46, Sibi Sankar wrote:
> From: Guru Das Srinagesh <quic_gurus@xxxxxxxxxxx>
>
> When the firmware (FW) supports multiple requests per VM, multiple requests
> from the same/different VM can reach the firmware at the same time. Since
> the firmware currently being used has limited resources, it guards them
> with a resource lock and puts requests on a wait-queue internally and
> signals to HLOS that it is doing so. It does this by returning a new return
> value in addition to success or error: SCM_WAITQ_SLEEP. A sleeping SCM call
> can be woken up by an interrupt that the FW raises.
Just two nitpicks while browsing the code...
> static int qcom_scm_probe(struct platform_device *pdev)
> {
> struct qcom_scm *scm;
> unsigned long clks;
> - int ret;
> + int irq, ret;
>
> scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
> if (!scm)
> @@ -1399,9 +1486,29 @@ static int qcom_scm_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + platform_set_drvdata(pdev, scm);
> +
> __scm = scm;
> __scm->dev = &pdev->dev;
>
> + spin_lock_init(&__scm->waitq.idr_lock);
> + idr_init(&__scm->waitq.idr);
> + init_completion(&__scm->waitq.waitq_comp);
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + if (irq != -ENXIO)
> + return irq;
> + } else {
> + ret = devm_request_threaded_irq(__scm->dev, irq, NULL, qcom_scm_irq_handler,
> + IRQF_ONESHOT, "qcom-scm", __scm);
> + if (ret < 0) {
> + dev_err(scm->dev, "Failed to request qcom-scm irq: %d\n", ret);
> + idr_destroy(&__scm->waitq.idr);
> + return ret;
return dev_err_probe().
> + }
> + }
> +
> __get_convention();
>
> /*
> @@ -1417,6 +1524,12 @@ static int qcom_scm_probe(struct platform_device *pdev)
>
> static void qcom_scm_shutdown(struct platform_device *pdev)
> {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&__scm->waitq.idr_lock, flags);
> + idr_destroy(&__scm->waitq.idr);
> + spin_unlock_irqrestore(&__scm->waitq.idr_lock, flags);
> +
> /* Clean shutdown, disable download mode to allow normal restart */
> if (download_mode)
> qcom_scm_set_download_mode(false);
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index db3d08a01209..323cb49d4976 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -60,6 +60,10 @@ struct qcom_scm_res {
> u64 result[MAX_QCOM_SCM_RETS];
> };
>
> +struct qcom_scm;
> +extern struct completion *qcom_scm_lookup_wq(struct qcom_scm *scm, u32 wq_ctx);
> +extern int scm_get_wq_ctx(u32 *wq_ctx, u32 *flags, u32 *more_pending);
No need for externs for new entries.
Best regards,
Krzysztof
