diff mbox series

[v4,07/35] iommu/mediatek: Add mutex for data in the mtk_iommu_domain

Message ID 20220125085634.17972-8-yong.wu@mediatek.com
State Accepted
Commit ddf67a87bebf2a8750d86f67cb298313ee93db31
Headers show
Series None | expand

Commit Message

Yong Wu (吴勇) Jan. 25, 2022, 8:56 a.m. UTC
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@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 095736bfb7b4..e6e4ee471867 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 */