[PATCH 2/3] iommu/vt-d: Clear Page Request Overflow fault bit

From: Lu Baolu
Date: Wed Oct 18 2017 - 20:44:55 EST


Currently Page Request Overflow bit in IOMMU Fault Status register
is not cleared. Not clearing this bit would mean that any future
page-request is going to be automatically dropped by IOMMU.

Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/dmar.c | 3 ++-
include/linux/intel-iommu.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 1ea7cd5..9a7ffd1 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1679,7 +1679,8 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
raw_spin_lock_irqsave(&iommu->register_lock, flag);
}

- writel(DMA_FSTS_PFO | DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);
+ writel(DMA_FSTS_PFO | DMA_FSTS_PPF | DMA_FSTS_PRO,
+ iommu->reg + DMAR_FSTS_REG);

unlock_exit:
raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 485a5b4..f3274d9 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -212,6 +212,7 @@
#define DMA_FSTS_IQE (1 << 4)
#define DMA_FSTS_ICE (1 << 5)
#define DMA_FSTS_ITE (1 << 6)
+#define DMA_FSTS_PRO (1 << 7)
#define dma_fsts_fault_record_index(s) (((s) >> 8) & 0xff)

/* FRCD_REG, 32 bits access */
--
2.7.4