From 925fe08bce38d1ff052fe2209b9e2b8d5fbb7f98 Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Wed, 27 Mar 2013 18:51:52 -0500 Subject: [PATCH] iommu/amd: Re-enable IOMMU event log interrupt after handling. Current driver does not clear the IOMMU event log interrupt bit in the IOMMU status register after processing an interrupt. This causes the IOMMU hardware to generate event log interrupt only once. This has been observed in both IOMMU v1 and V2 hardware. This patch clears the bit by writing 1 to bit 1 of the IOMMU status register (MMIO Offset 2020h) Signed-off-by: Suravee Suthikulpanit Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 3 +++ drivers/iommu/amd_iommu_types.h | 1 + 2 files changed, 4 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index b287ca33833d..d6433e2a3bb4 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -703,6 +703,9 @@ static void iommu_poll_events(struct amd_iommu *iommu) u32 head, tail; unsigned long flags; + /* enable event interrupts again */ + writel(MMIO_STATUS_EVT_INT_MASK, iommu->mmio_base + MMIO_STATUS_OFFSET); + spin_lock_irqsave(&iommu->lock, flags); head = readl(iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index e38ab438bb34..083f98c0488b 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -99,6 +99,7 @@ #define PASID_MASK 0x000fffff /* MMIO status bits */ +#define MMIO_STATUS_EVT_INT_MASK (1 << 1) #define MMIO_STATUS_COM_WAIT_INT_MASK (1 << 2) #define MMIO_STATUS_PPR_INT_MASK (1 << 6) -- 2.20.1