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From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Fri, 31 Jul 2020 00:14:20 +0800
Message-ID: <CAAOTY_9HXv+OsSRF7P9=cRy9AYZ0vwffgo3Kc8V=qQ6ce90uJw@mail.gmail.com>
Subject: Re: [PATCH v4 2/2] soc: mediatek: add mtk-devapc driver
To:     Neal Liu <neal.liu@mediatek.com>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        devicetree@vger.kernel.org,
        wsd_upstream <wsd_upstream@mediatek.com>,
        lkml <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
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Hi, Neal:

Neal Liu <neal.liu@mediatek.com> =E6=96=BC 2020=E5=B9=B47=E6=9C=8829=E6=97=
=A5 =E9=80=B1=E4=B8=89 =E4=B8=8B=E5=8D=884:29=E5=AF=AB=E9=81=93=EF=BC=9A
>
> MediaTek bus fabric provides TrustZone security support and data
> protection to prevent slaves from being accessed by unexpected
> masters.
> The security violation is logged and sent to the processor for
> further analysis or countermeasures.
>
> Any occurrence of security violation would raise an interrupt, and
> it will be handled by mtk-devapc driver. The violation
> information is printed in order to find the murderer.
>
> Signed-off-by: Neal Liu <neal.liu@mediatek.com>
> ---

[snip]

> +
> +/*
> + * devapc_extract_vio_dbg - extract full violation information after doi=
ng
> + *                          shift mechanism.
> + */
> +static void devapc_extract_vio_dbg(struct mtk_devapc_context *ctx)
> +{
> +       const struct mtk_devapc_vio_dbgs *vio_dbgs;
> +       struct mtk_devapc_vio_info *vio_info;
> +       void __iomem *vio_dbg0_reg;
> +       void __iomem *vio_dbg1_reg;
> +       u32 dbg0;
> +
> +       vio_dbg0_reg =3D ctx->devapc_pd_base + ctx->offset->vio_dbg0;
> +       vio_dbg1_reg =3D ctx->devapc_pd_base + ctx->offset->vio_dbg1;
> +
> +       vio_dbgs =3D ctx->vio_dbgs;
> +       vio_info =3D ctx->vio_info;
> +
> +       /* Starts to extract violation information */
> +       dbg0 =3D readl(vio_dbg0_reg);
> +       vio_info->vio_addr =3D readl(vio_dbg1_reg);
> +
> +       vio_info->master_id =3D (dbg0 & vio_dbgs->mstid.mask) >>
> +                             vio_dbgs->mstid.start;
> +       vio_info->domain_id =3D (dbg0 & vio_dbgs->dmnid.mask) >>
> +                             vio_dbgs->dmnid.start;
> +       vio_info->write =3D ((dbg0 & vio_dbgs->vio_w.mask) >>
> +                           vio_dbgs->vio_w.start) =3D=3D 1;
> +       vio_info->read =3D ((dbg0 & vio_dbgs->vio_r.mask) >>
> +                         vio_dbgs->vio_r.start) =3D=3D 1;
> +       vio_info->vio_addr_high =3D (dbg0 & vio_dbgs->addr_h.mask) >>
> +                                 vio_dbgs->addr_h.start;


I would like to define the type of ctx->vio_info to be

struct mtk_devapc_vio_dbgs {
    u32 mstid:16;
    u32 dmnid:6;
    u32 vio_w:1;
    u32 vio_r:1;
    u32 addr_h:4;
    u32 resv:4;
};

so the code would like the simple way

ctx->vio_info =3D (struct mtk_devapc_vio_dbgs)readl(vio_dbg1_reg);

Regards,
Chun-Kuang.

> +
> +       devapc_vio_info_print(ctx);
> +}
> +