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authorSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>2013-03-27 18:51:52 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-07 12:49:35 -0700
commita5d3e60fa23aa401a2f14ed58af32405c9915351 (patch)
treedf6244c5f03257f21ea5f8e6eb28139cc5aca123 /drivers
parentbaff3c88fd65974bc8d11bd7bab0d60bbe0325a6 (diff)
downloadlwn-a5d3e60fa23aa401a2f14ed58af32405c9915351.tar.gz
lwn-a5d3e60fa23aa401a2f14ed58af32405c9915351.zip
iommu/amd: Re-enable IOMMU event log interrupt after handling.
commit 925fe08bce38d1ff052fe2209b9e2b8d5fbb7f98 upstream. 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 <suravee.suthikulpanit@amd.com> Signed-off-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/amd_iommu.c3
-rw-r--r--drivers/iommu/amd_iommu_types.h1
2 files changed, 4 insertions, 0 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 0569843756e5..48f416aca055 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -534,6 +534,9 @@ 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 24355559a2ad..c4ffacb033f2 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)