From fae620b2b6a3160ecbd6216a01b806141fc1abdb Mon Sep 17 00:00:00 2001
From: Simon Xue <xxm@rock-chips.com>
Date: Wed, 7 Apr 2021 09:15:54 +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 202ea0e1d334..d55e1e0fb6c8 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -699,6 +699,7 @@ 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;
@@ -743,7 +744,15 @@ 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)
@@ -1570,6 +1579,37 @@ 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 d40451269cc5..01294da9bd07 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -579,6 +579,8 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain,
 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);
 /* FSL-MC device grouping function */
 struct iommu_group *fsl_mc_device_group(struct device *dev);
 
@@ -1087,6 +1089,14 @@ static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
 {
 	return NULL;
 }
+
+static inline void rk_iommu_mask_irq(struct device *dev)
+{
+}
+
+static inline void rk_iommu_unmask_irq(struct device *dev)
+{
+}
 #endif /* CONFIG_IOMMU_API */
 
 /**