mapping, the tlb flush is unnecessay since we already have tlb_flush_all
in the pm_runtime_resume callback. When the iommu's power status is
changed to active, the tlb always is clean.

In addition, there still are 2 reasons that don't add PM status checking
in the tlb flush all:
a) Write tlb flush all register also is ok even though the HW has no
power and clocks. Write ignore.
b) pm_runtime_get_if_in_use(m4udev) is 0 when the tlb_flush_all
is called frm pm_runtime_resume cb. From this point, we can not add
this code above in this tlb_flush_all.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
  drivers/iommu/mtk_iommu.c | 20 +++++++-------------
  1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index e9e94944ed91..4a33b6c6b1db 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c

@@ -204,10 +204,14 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
  	return container_of(dom, struct mtk_iommu_domain, domain);
  }
  
-static void mtk_iommu_tlb_do_flush_all(struct mtk_iommu_data *data)
+static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
  {
  	unsigned long flags;
  
+	/*
+	 * No need get power status since the HW PM status nearly is active
+	 * when entering here.
+	 */
  	spin_lock_irqsave(&data->tlb_lock, flags);
  	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
  		       data->base + data->plat_data->inv_sel_reg);

@@ -216,16 +220,6 @@ static void mtk_iommu_tlb_do_flush_all(struct mtk_iommu_data *data)
  	spin_unlock_irqrestore(&data->tlb_lock, flags);
  }
  
-static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
-{
-	if (pm_runtime_get_if_in_use(data->dev) <= 0)
-		return;
-
-	mtk_iommu_tlb_do_flush_all(data);
-
-	pm_runtime_put(data->dev);
-}
-
  static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
  					   struct mtk_iommu_data *data)
  {

@@ -263,7 +257,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
  		if (ret) {
  			dev_warn(data->dev,
  				 "Partial TLB flush timed out, falling back to full flush\n");
-			mtk_iommu_tlb_do_flush_all(data);
+			mtk_iommu_tlb_flush_all(data);
  		}
  
  		if (has_pm)

@@ -993,7 +987,7 @@ static int __maybe_unused mtk_iommu_runtime_resume(struct device *dev)
  	 *
  	 * Thus, Make sure the tlb always is clean after each PM resume.
  	 */
-	mtk_iommu_tlb_do_flush_all(data);
+	mtk_iommu_tlb_flush_all(data);
  
  	/*
  	 * Uppon first resume, only enable the clk and return, since the values of the