Re: [PATCH v6 06/10] soc: qcom: rpmhpd: Add RPMh power domain driver

Rajendra Nayak
2018-12-12T05:04:54Z

On 12/12/2018 3:31 AM, Stephen Boyd wrote:
> Quoting Rajendra Nayak (2018-12-11 01:49:34)
>> The RPMh power domain driver aggregates the corner votes from various
>> consumers for the ARC resources and communicates it to RPMh.
>>
>> With RPMh we use 2 different numbering space for corners, one used
>> by the clients to express their performance needs, and another used
>> to communicate to RPMh hardware.
>>
>> The clients express their performance requirements using a sparse
>> numbering space which are mapped to meaningful levels like RET, SVS,
>> NOMINAL, TURBO etc which then get mapped to another number space
>> between 0 and 15 which is communicated to RPMh. The sparse number space,
>> also referred to as vlvl is mapped to the continuous number space of 0
>> to 15, also referred to as hlvl, using command DB.
>>
>> Some power domain clients could request a performance state only while
>> the CPU is active, while some others could request for a certain
>> performance state all the time regardless of the state of the CPU.
>> We handle this by internally aggregating the votes from both type of
>> clients and then send the aggregated votes to RPMh.
>>
>> There are also 3 different types of Votes that are comunicated to RPMh
>
> Why capitalize vote?

will fix,

>
>> for every resource.
>> 1. ACTIVE_ONLY: This specifies the requirement for the resource when the
>> CPU is active
>> 2. SLEEP: This specifies the requirement for the resource when the CPU
>> is going to sleep
>> 3. WAKE_ONLY: This specifies the requirement for the resource when the
>> CPU is coming out of sleep to active state
>
> Can you tab these in?

sure, will do

>
>>
>> We add data for all power domains on sdm845 SoC as part of the patch.
>> The driver can be extended to support other SoCs which support RPMh
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
>
> Just minor nitpicks ahead and a warning.
>
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index f1b25fdcf2ad..dd6ca92985ee 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -22,3 +22,4 @@ obj-$(CONFIG_QCOM_APR) += apr.o
>> obj-$(CONFIG_QCOM_LLCC) += llcc-slice.o
>> obj-$(CONFIG_QCOM_SDM845_LLCC) += llcc-sdm845.o
>> obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
>> +obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
>
> Put this before RPMPD? At least it would be semi-sorted then.

okay, will do

>
>> diff --git a/drivers/soc/qcom/rpmhpd.c b/drivers/soc/qcom/rpmhpd.c
>> new file mode 100644
>> index 000000000000..f993a86be48c
>> --- /dev/null
>> +++ b/drivers/soc/qcom/rpmhpd.c
>> @@ -0,0 +1,417 @@
> [..]
>> +
>> +static int rpmhpd_update_level_mapping(struct rpmhpd *rpmhpd)
>> +{
>> + u8 buf[RPMH_ARC_MAX_LEVELS * RPMH_ARC_LEVEL_SIZE];
>> + int i, j, len, ret;
>> +
>> + len = cmd_db_read_aux_data_len(rpmhpd->res_name);
>> + if (len <= 0)
>> + return len;
>> + else if (len > RPMH_ARC_MAX_LEVELS * RPMH_ARC_LEVEL_SIZE)
>> + return -EINVAL;
>> +
>> + ret = cmd_db_read_aux_data(rpmhpd->res_name, buf, len);
>> + if (ret < 0)
>> + return ret;
>
> I've changed cmd_db_read_aux_data() and that change is winding through
> the arm-soc tree. This will break in the compilation phase in
> linux-next.

will resend these based on Andy's for-next

>
>> +
>> + rpmhpd->level_count = len / RPMH_ARC_LEVEL_SIZE;
>> +
>> + for (i = 0; i < rpmhpd->level_count; i++) {
>> + rpmhpd->level[i] = 0;
>> + for (j = 0; j < RPMH_ARC_LEVEL_SIZE; j++)
>> + rpmhpd->level[i] |=
>> + buf[i * RPMH_ARC_LEVEL_SIZE + j] << (8 * j);
>> +
>> + /*
>> + * The AUX data may be zero padded. These 0 valued entries at
>> + * the end of the map must be ignored.
>> + */
>> + if (i > 0 && rpmhpd->level[i] == 0) {
>> + rpmhpd->level_count = i;
>> + break;
>> + }
>> + pr_debug("%s: ARC hlvl=%2d --> vlvl=%4u\n", rpmhpd->res_name, i,
>> + rpmhpd->level[i]);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int rpmhpd_probe(struct platform_device *pdev)
>> +{
>> + int i, ret;
>> + size_t num_pds;
>> + struct device *dev = &pdev->dev;
>> + struct genpd_onecell_data *data;
>> + struct rpmhpd **rpmhpds;
>> + const struct rpmhpd_desc *desc;
>> +
>> + desc = of_device_get_match_data(dev);
>> + if (!desc)
>> + return -EINVAL;
>> +
>> + rpmhpds = desc->rpmhpds;
>> + num_pds = desc->num_pds;
>> +
>> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + data->domains = devm_kcalloc(dev, num_pds, sizeof(*data->domains),
>> + GFP_KERNEL);
>> + if (!data->domains)
>> + return -ENOMEM;
>> +
>> + data->num_domains = num_pds;
>> +
>> + ret = cmd_db_ready();
>
> Does this matter? I thought we forced cmd_db_ready() in the rpmh driver
> probe, and that was the parent of all rpmh devices so we should be fine
> to not need to check it again here?

sure, will remove.

thanks for the review.

>
>> + if (ret) {
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(dev, "Command DB unavailable, ret=%d\n", ret);
>> + return ret;
>> + }
>> +