Same with the previous patch, add a mutex for the "data" in the
mtk_iommu_domain. Just improve the safety for multi devices
enter attach_device at the same time. We don't get the real issue
for this.
Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
drivers/iommu/mtk_iommu.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 3413cc98e57e..ecdce5d3e8cf 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -128,6 +128,8 @@ struct mtk_iommu_domain {
struct mtk_iommu_data *data;
struct iommu_domain domain;
+
+ struct mutex mutex; /* Protect "data" in this structure */
};
static const struct iommu_ops mtk_iommu_ops;
@@ -434,6 +436,7 @@ static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
dom = kzalloc(sizeof(*dom), GFP_KERNEL);
if (!dom)
return NULL;
+ mutex_init(&dom->mutex);
return &dom->domain;
}
@@ -455,14 +458,19 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
if (domid < 0)
return domid;
+ mutex_lock(&dom->mutex);
if (!dom->data) {
/* Data is in the frstdata in sharing pgtable case. */
frstdata = mtk_iommu_get_m4u_data();
- if (mtk_iommu_domain_finalise(dom, frstdata, domid))
+ ret = mtk_iommu_domain_finalise(dom, frstdata, domid);
+ if (ret) {
+ mutex_unlock(&dom->mutex);
return -ENODEV;
+ }
dom->data = data;
}
+ mutex_unlock(&dom->mutex);
mutex_lock(&data->mutex);
if (!data->m4u_dom) { /* Initialize the M4U HW */
--
2.18.0
