Re: [PATCH v4 2/2] soc: mediatek: add mtk-devapc driver

Chun-Kuang Hu
2020-07-30T16:16:44Z

Hi, Neal:

Neal Liu <neal.liu@mediatek.com> 於 2020年7月29日 週三 下午4:29寫道：
>
> 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 doing
> + * 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 = ctx->devapc_pd_base + ctx->offset->vio_dbg0;
> + vio_dbg1_reg = ctx->devapc_pd_base + ctx->offset->vio_dbg1;
> +
> + vio_dbgs = ctx->vio_dbgs;
> + vio_info = ctx->vio_info;
> +
> + /* Starts to extract violation information */
> + dbg0 = readl(vio_dbg0_reg);
> + vio_info->vio_addr = readl(vio_dbg1_reg);
> +
> + vio_info->master_id = (dbg0 & vio_dbgs->mstid.mask) >>
> + vio_dbgs->mstid.start;
> + vio_info->domain_id = (dbg0 & vio_dbgs->dmnid.mask) >>
> + vio_dbgs->dmnid.start;
> + vio_info->write = ((dbg0 & vio_dbgs->vio_w.mask) >>
> + vio_dbgs->vio_w.start) == 1;
> + vio_info->read = ((dbg0 & vio_dbgs->vio_r.mask) >>
> + vio_dbgs->vio_r.start) == 1;
> + vio_info->vio_addr_high = (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 = (struct mtk_devapc_vio_dbgs)readl(vio_dbg1_reg);

Regards,
Chun-Kuang.

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