[PATCH 3/3] iommu/amd: Set IOTLB invalidation timeout

From: Joerg Roedel
Date: Thu Dec 22 2011 - 09:01:33 EST


To protect the command buffer from hanging when a device
does not respond to an IOTLB invalidation, set a timeout of
1s for outstanding IOTLB invalidations.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 13 +++++++++++++
drivers/iommu/amd_iommu_types.h | 10 ++++++++++
2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 38784733..bdea288 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -306,6 +306,16 @@ static void iommu_feature_disable(struct amd_iommu *iommu, u8 bit)
writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET);
}

+static void iommu_set_inv_tlb_timeout(struct amd_iommu *iommu, int timeout)
+{
+ u32 ctrl;
+
+ ctrl = readl(iommu->mmio_base + MMIO_CONTROL_OFFSET);
+ ctrl &= ~CTRL_INV_TO_MASK;
+ ctrl |= (timeout << CONTROL_INV_TIMEOUT) & CTRL_INV_TO_MASK;
+ writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET);
+}
+
/* Function to enable the hardware */
static void iommu_enable(struct amd_iommu *iommu)
{
@@ -1300,6 +1310,9 @@ static void iommu_init_flags(struct amd_iommu *iommu)
* make IOMMU memory accesses cache coherent
*/
iommu_feature_enable(iommu, CONTROL_COHERENT_EN);
+
+ /* Set IOTLB invalidation timeout to 1s */
+ iommu_set_inv_tlb_timeout(iommu, CTRL_INV_TO_1S);
}

static void iommu_apply_resume_quirks(struct amd_iommu *iommu)
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 6ad8b10..2452f3b 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -127,6 +127,7 @@
#define CONTROL_EVT_LOG_EN 0x02ULL
#define CONTROL_EVT_INT_EN 0x03ULL
#define CONTROL_COMWAIT_EN 0x04ULL
+#define CONTROL_INV_TIMEOUT 0x05ULL
#define CONTROL_PASSPW_EN 0x08ULL
#define CONTROL_RESPASSPW_EN 0x09ULL
#define CONTROL_COHERENT_EN 0x0aULL
@@ -137,6 +138,15 @@
#define CONTROL_PPR_EN 0x0fULL
#define CONTROL_GT_EN 0x10ULL

+#define CTRL_INV_TO_MASK (7 << CONTROL_INV_TIMEOUT)
+#define CTRL_INV_TO_NONE 0
+#define CTRL_INV_TO_1MS 1
+#define CTRL_INV_TO_10MS 2
+#define CTRL_INV_TO_100MS 3
+#define CTRL_INV_TO_1S 4
+#define CTRL_INV_TO_10S 5
+#define CTRL_INV_TO_100S 6
+
/* command specific defines */
#define CMD_COMPL_WAIT 0x01
#define CMD_INV_DEV_ENTRY 0x02
--
1.7.5.4


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