linux-kernel - [PATCH v10 04/13] iommu/mediatek: Add probe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220117070510.17642-5-yong.wu@mediatek.com>
Date:   Mon, 17 Jan 2022 15:05:01 +0800
From:   Yong Wu <yong.wu@...iatek.com>
To:     Matthias Brugger <matthias.bgg@...il.com>,
        Hans Verkuil <hverkuil@...all.nl>,
        Joerg Roedel <jroedel@...e.de>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>,
        David Airlie <airlied@...ux.ie>,
        "Mauro Carvalho Chehab" <mchehab@...nel.org>
CC:     Evan Green <evgreen@...omium.org>,
        Robin Murphy <robin.murphy@....com>,
        Tomasz Figa <tfiga@...omium.org>,
        Will Deacon <will.deacon@....com>,
        <linux-mediatek@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <iommu@...ts.linux-foundation.org>, <yong.wu@...iatek.com>,
        <youlin.pei@...iatek.com>, Matthias Kaehlcke <mka@...omium.org>,
        <anan.sun@...iatek.com>, <yi.kuo@...iatek.com>,
        <acourbot@...omium.org>, <linux-media@...r.kernel.org>,
        <dri-devel@...ts.freedesktop.org>, Daniel Vetter <daniel@...ll.ch>,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Tiffany Lin <tiffany.lin@...iatek.com>,
        "Dafna Hirschfeld" <dafna.hirschfeld@...labora.com>,
        Hsin-Yi Wang <hsinyi@...omium.org>,
        Eizan Miyamoto <eizan@...omium.org>,
        <anthony.huang@...iatek.com>,
        Frank Wunderlich <frank-w@...lic-files.de>,
        <mingyuan.ma@...iatek.com>, <yf.wang@...iatek.com>,
        <libo.kang@...iatek.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
Subject: [PATCH v10 04/13] iommu/mediatek: Add probe_defer for smi-larb

Prepare for adding device_link.

The iommu consumer should use device_link to connect with the
smi-larb(supplier). then the smi-larb should run before the iommu
consumer. Here we delay the iommu driver until the smi driver is ready,
then all the iommu consumers always are after the smi driver.

When there is no this patch, if some consumer drivers run before
smi-larb, the supplier link_status is DL_DEV_NO_DRIVER(0) in the
device_link_add, then device_links_driver_bound will use WARN_ON
to complain that the link_status of supplier is not right.

device_is_bound may be more elegant here. but it is not allowed to
EXPORT from https://lore.kernel.org/patchwork/patch/1334670/.

Signed-off-by: Yong Wu <yong.wu@...iatek.com>
Tested-by: Frank Wunderlich <frank-w@...lic-files.de> # BPI-R2/MT7623
Acked-by: Joerg Roedel <jroedel@...e.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
---
 drivers/iommu/mtk_iommu.c    | 4 ++++
 drivers/iommu/mtk_iommu_v1.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 77ae20ff9b35..5cff5bc556d4 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -850,6 +850,10 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 			of_node_put(larbnode);
 			return -ENODEV;
 		}
+		if (!plarbdev->dev.driver) {
+			of_node_put(larbnode);
+			return -EPROBE_DEFER;
+		}
 		data->larb_imu[id].dev = &plarbdev->dev;
 
 		component_match_add_release(dev, &match, release_of,
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 68bf02f87cfd..4089077256f4 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -606,6 +606,10 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 			of_node_put(larbnode);
 			return -ENODEV;
 		}
+		if (!plarbdev->dev.driver) {
+			of_node_put(larbnode);
+			return -EPROBE_DEFER;
+		}
 		data->larb_imu[i].dev = &plarbdev->dev;
 
 		component_match_add_release(dev, &match, release_of,
-- 
2.18.0