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authorChris Wright <chrisw@sous-sol.org>2009-06-15 15:53:45 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2009-06-15 15:53:45 +0200
commita8c485bb6857811807d42f9fd1fde2f5f89cc5c9 (patch)
treea87f877258454e5d48a39162d895a0fada250a36 /arch/x86
parent42a49f965a8d24ed92af04f5b564d63f17fd9c56 (diff)
amd-iommu: disable cmd buffer and evt logging before reprogramming iommu
The IOMMU spec states that IOMMU behavior may be undefined when the IOMMU registers are rewritten while command or event buffer is enabled. Disable them in IOMMU disable path. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/amd_iommu_init.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 575ca46211b..48a79b9b2f9 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -260,6 +260,14 @@ static void iommu_enable(struct amd_iommu *iommu)
static void iommu_disable(struct amd_iommu *iommu)
{
+ /* Disable command buffer */
+ iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
+
+ /* Disable event logging and event interrupts */
+ iommu_feature_disable(iommu, CONTROL_EVT_INT_EN);
+ iommu_feature_disable(iommu, CONTROL_EVT_LOG_EN);
+
+ /* Disable IOMMU hardware itself */
iommu_feature_disable(iommu, CONTROL_IOMMU_EN);
}
@@ -1042,6 +1050,7 @@ static void enable_iommus(void)
struct amd_iommu *iommu;
for_each_iommu(iommu) {
+ iommu_disable(iommu);
iommu_set_device_table(iommu);
iommu_enable_command_buffer(iommu);
iommu_enable_event_buffer(iommu);