Re: [PATCH v3 3/5] soc: qcom: smem: introduce qcom_smem_get_msm_id()

[Kathiravan T <quic_kathirav@quicinc.com>]

On 5/25/2023 5:39 PM, Robert Marko wrote:
> Introduce a helper to return the SoC SMEM ID, which is used to identify the
> exact SoC model as there may be differences in the same SoC family.
>
> Currently, cpufreq-nvmem does this completely in the driver and there has
> been more interest expresed for other drivers to use this information so
> lets expose a common helper to prevent redoing it in individual drivers
> since this field is present on every SMEM table version.
>
> Signed-off-by: Robert Marko <robimarko@gmail.com>
> ---
> Changes in v3:
> * Change export to EXPORT_SYMBOL_GPL
> * Use an argument for returning SoC ID
> * Update kerneldoc
> ---
>   drivers/soc/qcom/smem.c       | 24 ++++++++++++++++++++++++
>   include/linux/soc/qcom/smem.h |  2 ++
>   2 files changed, 26 insertions(+)
>
> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
> index bc98520c4969..185ed0da11a1 100644
> --- a/drivers/soc/qcom/smem.c
> +++ b/drivers/soc/qcom/smem.c
> @@ -14,6 +14,7 @@
>   #include <linux/sizes.h>
>   #include <linux/slab.h>
>   #include <linux/soc/qcom/smem.h>
> +#include <linux/soc/qcom/socinfo.h>
>   
>   /*
>    * The Qualcomm shared memory system is a allocate only heap structure that
> @@ -772,6 +773,29 @@ phys_addr_t qcom_smem_virt_to_phys(void *p)
>   }
>   EXPORT_SYMBOL_GPL(qcom_smem_virt_to_phys);
>   
> +/**
> + * qcom_smem_get_msm_id() - return the SoC ID
> + * @id:	On success, we return the SoC ID here.
> + *
> + * Look up SoC ID from HW/SW build ID and return it.
> + *
> + * Return: 0 on success, negative errno on failure.
> + */
> +int qcom_smem_get_msm_id(u32 *id)


I think, MSM  is not the only platform which will leverage this API. 
qcom_smem_get_soc_id() / qcom_smem_get_cpu_id() would make more sense 
than qcom_smem_get_msm_id() ?


> +{
> +	size_t len;
> +	struct socinfo *info;
> +
> +	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_HW_SW_BUILD_ID, &len);


len is unused after this, can we just pass NULL? Did a quick check on 
the code, if we pass the address, size of the item will be updated, else no.


> +	if (IS_ERR(info))
> +		return PTR_ERR(info);
> +
> +	*id = info->id;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_smem_get_msm_id);
> +
>   static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
>   {
>   	struct smem_header *header;
> diff --git a/include/linux/soc/qcom/smem.h b/include/linux/soc/qcom/smem.h
> index 86e1b358688a..cb204ad6373c 100644
> --- a/include/linux/soc/qcom/smem.h
> +++ b/include/linux/soc/qcom/smem.h
> @@ -11,4 +11,6 @@ int qcom_smem_get_free_space(unsigned host);
>   
>   phys_addr_t qcom_smem_virt_to_phys(void *p);
>   
> +int qcom_smem_get_msm_id(u32 *id);
> +
>   #endif