[PATCH 2/4] iommu/mediatek: Add irq handle for secure bank

[Yong Wu]

The secure bank registers are protected and can only be accessed in
the secure world, thus it won't be initialised in linux. In kernel, we only
need register the irq handle to report which iommu HW the secure
translation fault happen in.

We will enter the ATF to read the detail fault information. If ATF fail or
ATF isn't the debug load, we won't get the fault information, just print
a simple "secure bank fault" log.

Signed-off-by: Anan Sun <anan.sun at mediatek.com>
Signed-off-by: Yong Wu <yong.wu at mediatek.com>
---
 drivers/iommu/mtk_iommu.c  | 61 +++++++++++++++++++++++++++-----------
 include/soc/mediatek/smi.h |  1 +
 2 files changed, 45 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 4a2cffb28c61..e1faf2339b9a 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -465,22 +465,38 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
 	struct mtk_iommu_data *data = bank->parent_data;
 	struct mtk_iommu_domain *dom = bank->m4u_dom;
 	unsigned int fault_larb = MTK_INVALID_LARBID, fault_port = 0, sub_comm = 0;
-	u32 int_state, regval, va34_32, pa34_32;
 	const struct mtk_iommu_plat_data *plat_data = data->plat_data;
+	u32 int_state = ~0, regval = 0, va34_32, pa34_32;
+	u64 fault_iova = ~0ULL, fault_pa = ~0ULL;
 	void __iomem *base = bank->base;
-	u64 fault_iova, fault_pa;
+	struct arm_smccc_res res;
 	bool layer, write;
 
-	/* Read error info from registers */
-	int_state = readl_relaxed(base + REG_MMU_FAULT_ST1);
-	if (int_state & F_REG_MMU0_FAULT_MASK) {
-		regval = readl_relaxed(base + REG_MMU0_INT_ID);
-		fault_iova = readl_relaxed(base + REG_MMU0_FAULT_VA);
-		fault_pa = readl_relaxed(base + REG_MMU0_INVLD_PA);
+	if (bank->is_secure) {
+		/* Enter to secure world to Read fault status if it is secure bank. */
+		arm_smccc_smc(MTK_SIP_KERNEL_IOMMU_CONTROL,
+			      IOMMU_ATF_CMD_GET_SECURE_IOMMU_STATUS,
+			      bank->sec_bank_base, 0, 0, 0, 0, 0, &res);
+		if (res.a0 == 0) {
+			fault_iova = res.a1;
+			fault_pa = res.a2;
+			regval = res.a3;
+		} else {
+			dev_err_ratelimited(bank->parent_dev, "secure bank fault\n");
+			goto tlb_flush_all;
+		}
 	} else {
-		regval = readl_relaxed(base + REG_MMU1_INT_ID);
-		fault_iova = readl_relaxed(base + REG_MMU1_FAULT_VA);
-		fault_pa = readl_relaxed(base + REG_MMU1_INVLD_PA);
+		/* Read error info from registers */
+		int_state = readl_relaxed(base + REG_MMU_FAULT_ST1);
+		if (int_state & F_REG_MMU0_FAULT_MASK) {
+			regval = readl_relaxed(base + REG_MMU0_INT_ID);
+			fault_iova = readl_relaxed(base + REG_MMU0_FAULT_VA);
+			fault_pa = readl_relaxed(base + REG_MMU0_INVLD_PA);
+		} else {
+			regval = readl_relaxed(base + REG_MMU1_INT_ID);
+			fault_iova = readl_relaxed(base + REG_MMU1_FAULT_VA);
+			fault_pa = readl_relaxed(base + REG_MMU1_INVLD_PA);
+		}
 	}
 	layer = fault_iova & F_MMU_FAULT_VA_LAYER_BIT;
 	write = fault_iova & F_MMU_FAULT_VA_WRITE_BIT;
@@ -515,16 +531,19 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
 			       write ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ)) {
 		dev_err_ratelimited(
 			bank->parent_dev,
-			"fault type=0x%x iova=0x%llx pa=0x%llx master=0x%x(larb=%d port=%d) layer=%d %s\n",
-			int_state, fault_iova, fault_pa, regval, fault_larb, fault_port,
+			"bank(%u) fault type=0x%x iova=0x%llx pa=0x%llx master=0x%x(larb=%d port=%d) layer=%d %s\n",
+			bank->id, int_state, fault_iova, fault_pa, regval, fault_larb, fault_port,
 			layer, write ? "write" : "read");
 	}
 
 	/* Interrupt clear */
-	regval = readl_relaxed(base + REG_MMU_INT_CONTROL0);
-	regval |= F_INT_CLR_BIT;
-	writel_relaxed(regval, base + REG_MMU_INT_CONTROL0);
+	if (!bank->is_secure) {
+		regval = readl_relaxed(base + REG_MMU_INT_CONTROL0);
+		regval |= F_INT_CLR_BIT;
+		writel_relaxed(regval, base + REG_MMU_INT_CONTROL0);
+	}
 
+tlb_flush_all:
 	mtk_iommu_tlb_flush_all(data);
 
 	return IRQ_HANDLED;
@@ -1333,6 +1352,14 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 		bank->parent_dev = dev;
 		bank->parent_data = data;
 		spin_lock_init(&bank->tlb_lock);
+
+		/* Secure bank is initialised in secure world. Only need register irq here */
+		if (!bank->is_secure)
+			continue;
+		ret = devm_request_irq(bank->parent_dev, bank->irq, mtk_iommu_isr,
+				       0, dev_name(bank->parent_dev), (void *)bank);
+		if (ret)
+			return ret;
 	} while (++i < banks_num);
 
 	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_BCLK)) {
@@ -1426,7 +1453,7 @@ static void mtk_iommu_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	for (i = 0; i < data->plat_data->banks_num; i++) {
 		bank = &data->bank[i];
-		if (!bank->m4u_dom)
+		if (!bank->m4u_dom && !data->bank[i].is_secure)
 			continue;
 		devm_free_irq(&pdev->dev, bank->irq, bank);
 	}
diff --git a/include/soc/mediatek/smi.h b/include/soc/mediatek/smi.h
index 000eb1cf68b7..294550240aa6 100644
--- a/include/soc/mediatek/smi.h
+++ b/include/soc/mediatek/smi.h
@@ -14,6 +14,7 @@
 enum iommu_atf_cmd {
 	IOMMU_ATF_CMD_CONFIG_SMI_LARB,		/* For mm master to en/disable iommu */
 	IOMMU_ATF_CMD_CONFIG_INFRA_IOMMU,	/* For infra master to enable iommu */
+	IOMMU_ATF_CMD_GET_SECURE_IOMMU_STATUS,	/* Get secure iommu translation fault status */
 	IOMMU_ATF_CMD_MAX,
 };
 
-- 
2.25.1