Subject: Re: [PATCH v3 1/2] acpica: iort: Update SMMUv3 header for proximity
 domain mapping
To: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org
Cc: Will.Deacon@arm.com, lorenzo.pieralisi@arm.com, hanjun.guo@linaro.org,
        sudeep.holla@arm.com, lv.zheng@intel.com, joro@8bytes.org,
        rjw@rjwysocki.net, lenb@kernel.org, jnair@caviumnetworks.com,
        gpkulkarni@gmail.com
References: <1496897059-8272-1-git-send-email-ganapatrao.kulkarni@cavium.com>
 <1496897059-8272-2-git-send-email-ganapatrao.kulkarni@cavium.com>
From: Robin Murphy <robin.murphy@arm.com>
Message-ID: <0d0d6cb6-7674-5751-d780-af5114ddd569@arm.com>
Date: Mon, 19 Jun 2017 18:54:52 +0100
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On 08/06/17 05:44, Ganapatrao Kulkarni wrote:
> ARM IORT specification (rev. C) has added two new fields to define
> proximity domain for the SMMUv3 node in the IORT table.
> 
> Proximity Domain Valid:
> 	Set to 1 if the value provided in the Proximity Domain field is
> 	valid. Set to 0 otherwise.
> 
> Proximity domain:
> 	If the Proximity Domain Valid flag is set to 1, this entry
> 	provides the proximity domain to which this SMMU
> 	instance belongs.
> 
> Update header file to reflect this.
> 
> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> ---
>  include/acpi/actbl2.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
> index 4b306a6..389e91f 100644
> --- a/include/acpi/actbl2.h
> +++ b/include/acpi/actbl2.h
> @@ -805,6 +805,9 @@ struct acpi_iort_smmu_v3 {
>  	u32 pri_gsiv;
>  	u32 gerr_gsiv;
>  	u32 sync_gsiv;
> +	u8 pxm;
> +	u8 reserved1;
> +	u16 reserved2;

Why add the padding if you're not also adding the following field that
it aligns? (side note: could it not just be a u8[3]?)

If the actual structure definition is changing, do there not need to be
corresponding IASL changes too?

>  };
>  
>  /* Values for Model field above */
> @@ -817,6 +820,7 @@ struct acpi_iort_smmu_v3 {
>  
>  #define ACPI_IORT_SMMU_V3_COHACC_OVERRIDE   (1)
>  #define ACPI_IORT_SMMU_V3_HTTU_OVERRIDE     (1<<1)
> +#define ACPI_IORT_SMMU_V3_PXM_VALID         (1<<3)

Maybe it's just me, but "PXM" seems incredibly cryptic.

Robin.

>  
>  /*******************************************************************************
>   *
>