Re: [PATCH v5 08/20] iommu/mediatek: Add larb-id remapped support

From: Evan Green <evgreen-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
To: Yong Wu <yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Cc: youlin.pei-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Nicolas Boichat
	<drinkcat-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>,
	srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org,
	Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>,
	Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>,
	LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Tomasz Figa <tfiga-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Matthias Brugger
	<matthias.bgg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	yingjoe.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org,
	Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH v5 08/20] iommu/mediatek: Add larb-id remapped support
Date: Wed, 30 Jan 2019 10:29:33 -0800	[thread overview]
Message-ID: <CAE=gft7FOfqJir8n6wGvOcs0pdxtuvmd9jonHwD4Q_1Q8wM5oQ@mail.gmail.com> (raw)
In-Reply-To: <1546314952-15990-9-git-send-email-yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

On Mon, Dec 31, 2018 at 7:58 PM Yong Wu <yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> wrote:
>
> The larb-id may be remapped in the smi-common, this means the
> larb-id reported in the mtk_iommu_isr isn't the real larb-id,
>
> Take mt8183 as a example:
>                        M4U
>                         |
> ---------------------------------------------
> |               SMI common                  |
> -0-----7-----5-----6-----1-----2------3-----4- <- Id remapped
>  |     |     |     |     |     |      |     |
> larb0 larb1 IPU0  IPU1 larb4 larb5  larb6  CCU
> disp  vdec  img   cam   venc  img    cam
> As above, larb0 connects with the id 0 in smi-common.
>           larb1 connects with the id 7 in smi-common.
>           ...
> If the larb-id reported in the isr is 7, actually it's larb1(vdec).
> In order to output the right larb-id in the isr, we add a larb-id
> remapping relationship in this patch.
>
> If there is no this larb-id remapping in some SoCs, use the linear
> mapping array instead.
>
> This also is a preparing patch for mt8183.
>
> Signed-off-by: Yong Wu <yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>  drivers/iommu/mtk_iommu.c | 4 ++++
>  drivers/iommu/mtk_iommu.h | 2 ++
>  2 files changed, 6 insertions(+)
>
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 847082c..eca1536 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -220,6 +220,8 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
>         fault_larb = F_MMU0_INT_ID_LARB_ID(regval);
>         fault_port = F_MMU0_INT_ID_PORT_ID(regval);
>
> +       fault_larb = data->plat_data->larbid_remap[fault_larb];
> +
>         if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
>                                write ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ)) {
>                 dev_err_ratelimited(
> @@ -742,12 +744,14 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
>         .m4u_plat     = M4U_MT2712,
>         .has_4gb_mode = true,
>         .has_bclk     = true,
> +       .larbid_remap = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
>  };
>
>  static const struct mtk_iommu_plat_data mt8173_data = {
>         .m4u_plat     = M4U_MT8173,
>         .has_4gb_mode = true,
>         .has_bclk     = true,
> +       .larbid_remap = {0, 1, 2, 3, 4, 5}, /* Linear mapping. */

I briefly considered bikeshedding about how to define these arrays in
a way that might save memory for linear-map devices, but then decided
this is fine.

Reviewed-by: Evan Green <evgreen-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>