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authorTakao Indoh <indou.takao@jp.fujitsu.com>2013-04-23 17:35:03 +0900
committerJoerg Roedel <joro@8bytes.org>2013-04-23 14:47:08 +0200
commit3a93c841c2b3b14824f7728dd74bd00a1cedb806 (patch)
tree7b4a66f8caceac55b0832b635d537f7a04126eae
parent35d3d814cbd46a85bed97cd74ba97fbbb51e0ccd (diff)
iommu/vt-d: Disable translation if already enabled
This patch disables translation(dma-remapping) before its initialization if it is already enabled. This is needed for kexec/kdump boot. If dma-remapping is enabled in the first kernel, it need to be disabled before initializing its page table during second kernel boot. Wei Hu also reported that this is needed when second kernel boots with intel_iommu=off. Basically iommu->gcmd is used to know whether translation is enabled or disabled, but it is always zero at boot time even when translation is enabled since iommu->gcmd is initialized without considering such a case. Therefor this patch synchronizes iommu->gcmd value with global command register when iommu structure is allocated. Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
-rw-r--r--drivers/iommu/dmar.c11
-rw-r--r--drivers/iommu/intel-iommu.c15
2 files changed, 25 insertions, 1 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 9f8aa07360ba..f7890edb22f5 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -645,7 +645,7 @@ out:
int alloc_iommu(struct dmar_drhd_unit *drhd)
{
struct intel_iommu *iommu;
- u32 ver;
+ u32 ver, sts;
static int iommu_allocated = 0;
int agaw = 0;
int msagaw = 0;
@@ -695,6 +695,15 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
(unsigned long long)iommu->cap,
(unsigned long long)iommu->ecap);
+ /* Reflect status in gcmd */
+ sts = readl(iommu->reg + DMAR_GSTS_REG);
+ if (sts & DMA_GSTS_IRES)
+ iommu->gcmd |= DMA_GCMD_IRE;
+ if (sts & DMA_GSTS_TES)
+ iommu->gcmd |= DMA_GCMD_TE;
+ if (sts & DMA_GSTS_QIES)
+ iommu->gcmd |= DMA_GCMD_QIE;
+
raw_spin_lock_init(&iommu->register_lock);
drhd->iommu = iommu;
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0099667a397e..414d2d20dd59 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3665,6 +3665,7 @@ static struct notifier_block device_nb = {
int __init intel_iommu_init(void)
{
int ret = 0;
+ struct dmar_drhd_unit *drhd;
/* VT-d is required for a TXT/tboot launch, so enforce that */
force_on = tboot_force_iommu();
@@ -3675,6 +3676,20 @@ int __init intel_iommu_init(void)
return -ENODEV;
}
+ /*
+ * Disable translation if already enabled prior to OS handover.
+ */
+ for_each_drhd_unit(drhd) {
+ struct intel_iommu *iommu;
+
+ if (drhd->ignored)
+ continue;
+
+ iommu = drhd->iommu;
+ if (iommu->gcmd & DMA_GCMD_TE)
+ iommu_disable_translation(iommu);
+ }
+
if (dmar_dev_scope_init() < 0) {
if (force_on)
panic("tboot: Failed to initialize DMAR device scope\n");