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authorTakao Indoh <indou.takao@jp.fujitsu.com>2013-04-23 17:35:03 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-28 07:06:46 -0700
commit21870a3ce73bc351e2e3adffdea863e681556f2d (patch)
tree3d4527b65cf5029c7295c16c27a111436e67045b
parent5dc1c8851364ffb79cb9403f72c712ee83cce755 (diff)
iommu/vt-d: Disable translation if already enabled
commit 3a93c841c2b3b14824f7728dd74bd00a1cedb806 upstream. 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> [wyj: Backported to 3.4: adjust context] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 97b2e21ac46a..cf065df9bb18 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -582,7 +582,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
{
struct intel_iommu *iommu;
int map_size;
- u32 ver;
+ u32 ver, sts;
static int iommu_allocated = 0;
int agaw = 0;
int msagaw = 0;
@@ -652,6 +652,15 @@ 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 4e1c6bfc9c8d..dd255c578ad9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3659,6 +3659,7 @@ 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();
@@ -3669,6 +3670,20 @@ 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");