[PATCH v7 07/36] iommu/mediatek: Add mutex for m4u_group and m4u_dom in data

[Yong Wu via iommu]

Add a mutex to protect the data in the structure mtk_iommu_data,
like ->"m4u_group" ->"m4u_dom". For the internal data, we should
protect it in ourselves driver. Add a mutex for this.
This could be a fix for the multi-groups support.

Fixes: c3045f39244e ("iommu/mediatek: Support for multi domains")
Signed-off-by: Yunfei Wang <yf.w...@mediatek.com>
Signed-off-by: Yong Wu <yong...@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno 
<angelogioacchino.delre...@collabora.com>
---
 drivers/iommu/mtk_iommu.c | 13 +++++++++++--
 drivers/iommu/mtk_iommu.h |  2 ++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 81b8db450eac..3413cc98e57e 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -464,15 +464,16 @@ static int mtk_iommu_attach_device(struct iommu_domain 
*domain,
                dom->data = data;
        }
 
+       mutex_lock(&data->mutex);
        if (!data->m4u_dom) { /* Initialize the M4U HW */
                ret = pm_runtime_resume_and_get(m4udev);
                if (ret < 0)
-                       return ret;
+                       goto err_unlock;
 
                ret = mtk_iommu_hw_init(data);
                if (ret) {
                        pm_runtime_put(m4udev);
-                       return ret;
+                       goto err_unlock;
                }
                data->m4u_dom = dom;
                writel(dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK,
@@ -480,9 +481,14 @@ static int mtk_iommu_attach_device(struct iommu_domain 
*domain,
 
                pm_runtime_put(m4udev);
        }
+       mutex_unlock(&data->mutex);
 
        mtk_iommu_config(data, dev, true, domid);
        return 0;
+
+err_unlock:
+       mutex_unlock(&data->mutex);
+       return ret;
 }
 
 static void mtk_iommu_detach_device(struct iommu_domain *domain,
@@ -622,6 +628,7 @@ static struct iommu_group *mtk_iommu_device_group(struct 
device *dev)
        if (domid < 0)
                return ERR_PTR(domid);
 
+       mutex_lock(&data->mutex);
        group = data->m4u_group[domid];
        if (!group) {
                group = iommu_group_alloc();
@@ -630,6 +637,7 @@ static struct iommu_group *mtk_iommu_device_group(struct 
device *dev)
        } else {
                iommu_group_ref_get(group);
        }
+       mutex_unlock(&data->mutex);
        return group;
 }
 
@@ -910,6 +918,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
        }
 
        platform_set_drvdata(pdev, data);
+       mutex_init(&data->mutex);
 
        ret = iommu_device_sysfs_add(&data->iommu, dev, NULL,
                                     "mtk-iommu.%pa", &ioaddr);
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index b742432220c5..5e8da947affc 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -80,6 +80,8 @@ struct mtk_iommu_data {
 
        struct dma_iommu_mapping        *mapping; /* For mtk_iommu_v1.c */
 
+       struct mutex                    mutex; /* Protect m4u_group/m4u_dom 
above */
+
        struct list_head                list;
        struct mtk_smi_larb_iommu       larb_imu[MTK_LARB_NR_MAX];
 };
-- 
2.18.0

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