Re: [PATCH 2/3] firmware: qcom: scm: Add function to set the maximum IOMMU pool size

[Alex Elder <elder@xxxxxxxxxx>]

On 12/8/21 2:34 AM, Marijn Suijten wrote:
> From: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
>
> This is not necessary for basic functionality of the IOMMU, but
> it's an optimization that tells to the TZ what's the maximum
> mappable size for the secure IOMMUs, so that it can optimize
> the data structures in the TZ itself.

Are there no users of this function?	-Alex

> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> [Marijn: ported from 5.3 to the unified architecture in 5.11]
> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
> ---
>   drivers/firmware/qcom_scm.c | 15 +++++++++++++++
>   drivers/firmware/qcom_scm.h |  1 +
>   include/linux/qcom_scm.h    |  1 +
>   3 files changed, 17 insertions(+)
>
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index 3f67bf774821..d5a9ba15e2ba 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -759,6 +759,21 @@ int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare)
>   }
>   EXPORT_SYMBOL(qcom_scm_iommu_secure_ptbl_init);
>   
> +int qcom_scm_iommu_set_cp_pool_size(u32 spare, u32 size)
> +{
> +	struct qcom_scm_desc desc = {
> +		.svc = QCOM_SCM_SVC_MP,
> +		.cmd = QCOM_SCM_MP_IOMMU_SET_CP_POOL_SIZE,
> +		.arginfo = QCOM_SCM_ARGS(2),
> +		.args[0] = size,
> +		.args[1] = spare,
> +		.owner = ARM_SMCCC_OWNER_SIP,
> +	};
> +
> +	return qcom_scm_call(__scm->dev, &desc, NULL);
> +}
> +EXPORT_SYMBOL(qcom_scm_iommu_set_cp_pool_size);
> +
>   int qcom_scm_mem_protect_video_var(u32 cp_start, u32 cp_size,
>   				   u32 cp_nonpixel_start,
>   				   u32 cp_nonpixel_size)
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index d92156ceb3ac..bb627941702b 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -100,6 +100,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
>   #define QCOM_SCM_MP_RESTORE_SEC_CFG		0x02
>   #define QCOM_SCM_MP_IOMMU_SECURE_PTBL_SIZE	0x03
>   #define QCOM_SCM_MP_IOMMU_SECURE_PTBL_INIT	0x04
> +#define QCOM_SCM_MP_IOMMU_SET_CP_POOL_SIZE	0x05
>   #define QCOM_SCM_MP_VIDEO_VAR			0x08
>   #define QCOM_SCM_MP_ASSIGN			0x16
>   
> diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> index 81cad9e1e412..8a065f8660c1 100644
> --- a/include/linux/qcom_scm.h
> +++ b/include/linux/qcom_scm.h
> @@ -83,6 +83,7 @@ extern bool qcom_scm_restore_sec_cfg_available(void);
>   extern int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);
>   extern int qcom_scm_iommu_secure_ptbl_size(u32 spare, size_t *size);
>   extern int qcom_scm_iommu_secure_ptbl_init(u64 addr, u32 size, u32 spare);
> +extern int qcom_scm_iommu_set_cp_pool_size(u32 spare, u32 size);
>   extern int qcom_scm_mem_protect_video_var(u32 cp_start, u32 cp_size,
>   					  u32 cp_nonpixel_start,
>   					  u32 cp_nonpixel_size);