[PATCH v2 4/5] iommu/mediatek: Add tlb_lock in tlb_flush_all

[Dafna Hirschfeld]

From: Yong Wu <yong.wu at mediatek.com>

The tlb_flush_all touches the registers controlling tlb operations.
Protect it with the tlb_lock spinlock.
This also require the range_sync func to release that spinlock before
calling tlb_flush_all.

Signed-off-by: Yong Wu <yong.wu at mediatek.com>
[refactor commit log]
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld at collabora.com>
---
 drivers/iommu/mtk_iommu.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index e30ac68fab48..195a411e3087 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -210,10 +210,14 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
 
 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&data->tlb_lock, flags);
 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
 		       data->base + data->plat_data->inv_sel_reg);
 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
 	wmb(); /* Make sure the tlb flush all done */
+	spin_unlock_irqrestore(&data->tlb_lock, flags);
 }
 
 static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
@@ -242,14 +246,16 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
 		/* tlb sync */
 		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
 						tmp, tmp != 0, 10, 1000);
+
+		/* Clear the CPE status */
+		writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
+		spin_unlock_irqrestore(&data->tlb_lock, flags);
+
 		if (ret) {
 			dev_warn(data->dev,
 				 "Partial TLB flush timed out, falling back to full flush\n");
 			mtk_iommu_tlb_flush_all(data);
 		}
-		/* Clear the CPE status */
-		writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
-		spin_unlock_irqrestore(&data->tlb_lock, flags);
 
 		pm_runtime_put(data->dev);
 	}
-- 
2.17.1