From b1d57302177b30b71f1ca7c27cbb56ec82c75777 Mon Sep 17 00:00:00 2001
From: Simon Xue <xxm@rock-chips.com>
Date: Wed, 28 Oct 2020 09:15:51 +0800
Subject: [PATCH] iommu/rockchip: add irq mask cb

Change-Id: I5d2d565340395fb3573c7f25d764ed9f66333aeb
Signed-off-by: Simon Xue <xxm@rock-chips.com>
---
 drivers/iommu/rockchip-iommu.c | 42 +++++++++++++++++++++++++++++++++-
 include/linux/iommu.h          | 10 ++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 254aac857137..30329d79da30 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -690,6 +690,7 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
 	struct rk_iommu *iommu = dev_id;
 	u32 status;
 	u32 int_status;
+	u32 int_mask;
 	dma_addr_t iova;
 	irqreturn_t ret = IRQ_NONE;
 	int i, err;
@@ -734,7 +735,15 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
 				dev_err(iommu->dev, "Page fault while iommu not attached to domain?\n");
 
 			rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
-			rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_PAGE_FAULT_DONE);
+
+			/*
+			 * Master may clear the int_mask to prevent iommu
+			 * re-enter interrupt when mapping. So we postpone
+			 * sending PAGE_FAULT_DONE command to mapping finished.
+			 */
+			int_mask = rk_iommu_read(iommu->bases[i], RK_MMU_INT_MASK);
+			if (int_mask != 0x0)
+				rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_PAGE_FAULT_DONE);
 		}
 
 		if (int_status & RK_MMU_IRQ_BUS_ERROR)
@@ -1553,6 +1562,37 @@ static int rk_iommu_of_xlate(struct device *dev,
 	return 0;
 }
 
+void rk_iommu_mask_irq(struct device *dev)
+{
+	struct rk_iommu *iommu = rk_iommu_from_dev(dev);
+	int i;
+
+	if (!iommu)
+		return;
+
+	for (i = 0; i < iommu->num_mmu; i++)
+		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, 0);
+}
+EXPORT_SYMBOL(rk_iommu_mask_irq);
+
+void rk_iommu_unmask_irq(struct device *dev)
+{
+	struct rk_iommu *iommu = rk_iommu_from_dev(dev);
+	int i;
+
+	if (!iommu)
+		return;
+
+	for (i = 0; i < iommu->num_mmu; i++) {
+		/* Need to zap tlb in case of mapping during pagefault */
+		rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
+		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, RK_MMU_IRQ_MASK);
+		/* Leave iommu in pagefault state until mapping finished */
+		rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_PAGE_FAULT_DONE);
+	}
+}
+EXPORT_SYMBOL(rk_iommu_unmask_irq);
+
 static const struct iommu_ops rk_iommu_ops = {
 	.domain_alloc = rk_iommu_domain_alloc,
 	.domain_free = rk_iommu_domain_free,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4950233a1e96..c5470ac7451c 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -465,6 +465,8 @@ extern void iommu_reg_write(struct iommu_domain *domain, unsigned long offset,
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */
 extern struct iommu_group *generic_device_group(struct device *dev);
+extern void rk_iommu_mask_irq(struct device *dev);
+extern void rk_iommu_unmask_irq(struct device *dev);
 
 static inline void iommu_tlbiall(struct iommu_domain *domain)
 {
@@ -837,6 +839,14 @@ static inline int iommu_is_available(struct device *dev)
 {
 	return -ENODEV;
 }
+
+static inline void rk_iommu_mask_irq(struct device *dev)
+{
+}
+
+static inline void rk_iommu_unmask_irq(struct device *dev)
+{
+}
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_DEBUGFS