[PATCH v2 4/5] iommu/exynos: Add iommu fault handler

[Kukjin Kim]

From: KyongHo Cho <pullip.cho at samsung.com>

This adds IOMMU fault handler that is suggested by Ohad Ben-Cohen.

Users of IOMMU API can register its own fault handler with
iommu_set_fault_handler() and the handler is called by IRQ handler
of System MMU.

If no user installs fault handler, IOMMU driver prints debugging
message and generates kernel oops.

Signed-off-by: KyongHo Cho <pullip.cho at samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
---
 drivers/iommu/exynos_iommu.c |   21 +++++++++++++--------
 1 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/exynos_iommu.c b/drivers/iommu/exynos_iommu.c
index 33fa4a8..d355a2e 100644
--- a/drivers/iommu/exynos_iommu.c
+++ b/drivers/iommu/exynos_iommu.c
@@ -207,28 +207,33 @@ static int default_fault_handler(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
 static irqreturn_t exynos_sysmmu_irq(int irq, void * dev_id)
 {
 	/* SYSMMU is in blocked when interrupt occurred. */
+	unsigned long addr;
 	struct sysmmu_drvdata *data = dev_id;
 	enum S5P_SYSMMU_INTERRUPT_TYPE itype;
-	bool handled = false;
+	int ret = -ENOSYS;
 
 	WARN_ON(!is_sysmmu_active(data));
 
 	itype = (enum S5P_SYSMMU_INTERRUPT_TYPE)
 		__ffs(__raw_readl(data->sfrbase + S5P_INT_STATUS));
 
-	if (WARN_ON((itype < 0) && (itype >= 8))) {
+	if (WARN_ON((itype < 0) && (itype >= 8)))
 		itype = SYSMMU_FAULT_UNKNOWN;
-	} else if (data->fault_handler) {
+
+	addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);
+
+	if (data->domain)
+		ret = report_iommu_fault(data->domain, data->owner, addr,
+									itype);
+
+	if ((ret == -ENOSYS) && (data->fault_handler)) {
 		unsigned long base;
-		unsigned long addr;
-		addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);
 		base = __raw_readl(data->sfrbase + S5P_PT_BASE_ADDR);
 
-		if (!data->fault_handler(itype, base, addr))
-			handled = true;
+		ret = data->fault_handler(itype, base, addr);
 	}
 
-	if (handled)
+	if (ret == 0)
 		__raw_writel(1 << itype, data->sfrbase + S5P_INT_CLEAR);
 	else
 		dev_dbg(data->dev, "%s is not handled.\n",
-- 
1.7.1