Re: [PATCH v2 6/7] remoteproc: qcom_q6v5_pas: Add support to attach a DSP

Melody Olvera
2023-03-20T23:48:05Z

On 3/15/2023 7:27 PM, Bjorn Andersson wrote:
> On Mon, Mar 06, 2023 at 03:12:01PM -0800, Melody Olvera wrote:
>> Some chipsets will have DSPs which will have begun running prior
>> to linux booting, so add support to late attach these DSPs by
>> adding support for:
>> - run-time checking of an offline or running DSP via rmb register
>> - a late attach framework to attach to the running DSP
>> - a handshake mechanism to ensure full and proper booting via rmb
>>
>> Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>
>> ---
>> drivers/remoteproc/qcom_q6v5_pas.c | 103 ++++++++++++++++++++++++++++-
>> 1 file changed, 102 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
>> index 0871108fb4dc..e22be6a029a8 100644
>> --- a/drivers/remoteproc/qcom_q6v5_pas.c
>> +++ b/drivers/remoteproc/qcom_q6v5_pas.c
>> @@ -242,10 +242,89 @@ static int adsp_load(struct rproc *rproc, const struct firmware *fw)
>> return ret;
>> }
>>
>> +static int adsp_attach(struct rproc *rproc)
>> +{
>> + struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
>> + int i, ret;
>> +
>> + ret = qcom_q6v5_prepare(&adsp->q6v5);
>> + if (ret)
>> + return ret;
>> +
>> + ret = adsp_pds_enable(adsp, adsp->proxy_pds, adsp->proxy_pd_count);
>> + if (ret < 0)
>> + goto disable_irqs;
>> +
>> + ret = clk_prepare_enable(adsp->xo);
>> + if (ret)
>> + goto disable_proxy_pds;
>> +
>> + ret = clk_prepare_enable(adsp->aggre2_clk);
>> + if (ret)
>> + goto disable_xo_clk;
>> +
>> + if (adsp->cx_supply) {
>> + ret = regulator_enable(adsp->cx_supply);
>> + if (ret)
>> + goto disable_aggre2_clk;
>> + }
>> +
>> + if (adsp->px_supply) {
>> + ret = regulator_enable(adsp->px_supply);
>> + if (ret)
>> + goto disable_cx_supply;
>> + }
>> +
>> + /* if needed, signal Q6 to continute booting */
>> + if (adsp->q6v5.rmb_base) {
>> + for (i = 0; i < RMB_POLL_MAX_TIMES; i++) {
>> + if (readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
>> + writel_relaxed(1, adsp->q6v5.rmb_base + RMB_BOOT_CONT_REG);
>> + break;
>> + }
>> + msleep(20);
>> + }
>> +
>> + if (!readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
>> + dev_err(adsp->dev, "Didn't get rmb signal from %s\n", rproc->name);
>> + goto disable_px_supply;
>> + }
>> + }
>> +
>> + ret = qcom_q6v5_wait_for_start(&adsp->q6v5, msecs_to_jiffies(5000));
>> + if (ret == -ETIMEDOUT) {
>> + dev_err(adsp->dev, "start timed out\n");
>> + qcom_scm_pas_shutdown(adsp->pas_id);
>> + goto disable_px_supply;
>> + }
>> +
>> + return 0;
>> +
>> +disable_px_supply:
>> + if (adsp->px_supply)
>> + regulator_disable(adsp->px_supply);
>> +disable_cx_supply:
>> + if (adsp->cx_supply)
>> + regulator_disable(adsp->cx_supply);
>> +disable_aggre2_clk:
>> + clk_disable_unprepare(adsp->aggre2_clk);
>> +disable_xo_clk:
>> + clk_disable_unprepare(adsp->xo);
>> +disable_proxy_pds:
>> + adsp_pds_disable(adsp, adsp->proxy_pds, adsp->proxy_pd_count);
>> +disable_irqs:
>> + qcom_q6v5_unprepare(&adsp->q6v5);
>> +
>> + /* Remove pointer to the loaded firmware, only valid in adsp_load() & adsp_start() */
>> + adsp->firmware = NULL;
>> +
>> + return ret;
>> +}
>> +
>> static int adsp_start(struct rproc *rproc)
>> {
>> struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
>> - int ret;
>> + int i, ret;
>>
>> ret = qcom_q6v5_prepare(&adsp->q6v5);
>> if (ret)
>> @@ -304,6 +383,22 @@ static int adsp_start(struct rproc *rproc)
>> goto release_pas_metadata;
>> }
>>
>> + /* if needed, signal Q6 to continute booting */
> Why does this come before the wait_for_start()? Is the DSP actually up
> and running when you hit attach, or is it just loaded?

Yeah so DSP is loaded and partially booted, but it's waiting for a signal from our driver
to complete the boot process through to err_ready.

>
>> + if (adsp->q6v5.rmb_base) {
> Afaict this is copy-paste from attach, please move it to a helper
> function.

Sure.

>
>> + for (i = 0; i < RMB_POLL_MAX_TIMES; i++) {
>> + if (readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
>> + writel_relaxed(1, adsp->q6v5.rmb_base + RMB_BOOT_CONT_REG);
>> + break;
>> + }
>> + msleep(20);
>> + }
>> +
>> + if (!readl_relaxed(adsp->q6v5.rmb_base + RMB_BOOT_WAIT_REG)) {
> If you hit the break above, there should be no reason to read this
> register again.
>
> Seems cleaner to write this as:
>
> ret = readl_poll_timeout();
> if (ret < 0)
> goto release;
>
> writel(1, ...);

That is much cleaner; I didn't know about the poll timeout function. Will rewrite using it.

Thanks,
Melody
>
> Regards,
> Bjorn
>
>> + dev_err(adsp->dev, "Didn't get rmb signal from %s\n", rproc->name);
>> + goto release_pas_metadata;
>> + }
>> + }
>> +
>> ret = qcom_q6v5_wait_for_start(&adsp->q6v5, msecs_to_jiffies(5000));
>> if (ret == -ETIMEDOUT) {
>> dev_err(adsp->dev, "start timed out\n");
>> @@ -413,6 +508,7 @@ static unsigned long adsp_panic(struct rproc *rproc)
>> static const struct rproc_ops adsp_ops = {
>> .unprepare = adsp_unprepare,
>> .start = adsp_start,
>> + .attach = adsp_attach,
>> .stop = adsp_stop,
>> .da_to_va = adsp_da_to_va,
>> .parse_fw = qcom_register_dump_segments,
>> @@ -423,6 +519,7 @@ static const struct rproc_ops adsp_ops = {
>> static const struct rproc_ops adsp_minidump_ops = {
>> .unprepare = adsp_unprepare,
>> .start = adsp_start,
>> + .attach = adsp_attach,
>> .stop = adsp_stop,
>> .da_to_va = adsp_da_to_va,
>> .load = adsp_load,
>> @@ -728,6 +825,10 @@ static int adsp_probe(struct platform_device *pdev)
>> if (ret)
>> goto detach_proxy_pds;
>>
>> + if (adsp->q6v5.rmb_base &&
>> + readl_relaxed(adsp->q6v5.rmb_base + RMB_Q6_BOOT_STATUS_REG))
>> + rproc->state = RPROC_DETACHED;
>> +
>> qcom_add_glink_subdev(rproc, &adsp->glink_subdev, desc->ssr_name);
>> qcom_add_smd_subdev(rproc, &adsp->smd_subdev);
>> adsp->sysmon = qcom_add_sysmon_subdev(rproc,
>> --
>> 2.25.1
>>