In case the AMD IOMMU driver fails to enable interrupt, it currently
results in failure to boot due to invalid dma_ops for buses and devices
previously set when they were added to the IOMMU.
Therefore, fix this by unsetting the bus's iommu, and setup end-point
devices to use dma_direct_ops.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
drivers/iommu/amd_iommu.c | 14 +++++++++++++-
drivers/iommu/amd_iommu_init.c | 19 +++++++++++++++++--
drivers/iommu/amd_iommu_proto.h | 2 ++
3 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 5337fb2..3446763 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -381,6 +381,9 @@ static bool check_device(struct device *dev)
{
int devid;
+ if (amd_iommu_failed_initialize())
+ return false;
+
if (!dev || !dev->dma_mask)
return false;
@@ -486,7 +489,7 @@ static void iommu_uninit_device(struct device *dev)
iommu_group_remove_device(dev);
/* Remove dma-ops */
- dev->dma_ops = NULL;
+ dev->dma_ops = &dma_direct_ops;
/*
* We keep dev_data around for unplugged devices and reuse it when the
@@ -2722,6 +2725,15 @@ static int init_reserved_iova_ranges(void)
return 0;
}
+void __init amd_iommu_uninit_api(void)
+{
+ bus_unset_iommu(&pci_bus_type, &amd_iommu_ops);
+#ifdef CONFIG_ARM_AMBA
+ bus_unset_iommu(&amba_bustype, &amd_iommu_ops);
+#endif
+ bus_unset_iommu(&platform_bus_type, &amd_iommu_ops);
+}
+
int __init amd_iommu_init_api(void)
{
int ret, err = 0;
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 09d271e..d3f9cb3 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -245,6 +245,7 @@ enum iommu_init_state {
IOMMU_INITIALIZED,
IOMMU_NOT_FOUND,
IOMMU_INIT_ERROR,
+ IOMMU_RESOURCE_FREE,
IOMMU_CMDLINE_DISABLED,
};
@@ -307,6 +308,11 @@ int amd_iommu_get_num_iommus(void)
return amd_iommus_present;
}
+bool amd_iommu_failed_initialize(void)
+{
+ return init_state == IOMMU_RESOURCE_FREE;
+}
+
/* Access to l1 and l2 indexed register spaces */
static u32 iommu_read_l1(struct amd_iommu *iommu, u16 l1, u8 address)
@@ -2331,10 +2337,14 @@ static void __init free_iommu_resources(void)
free_iommu_all();
+ /*
+ * We failed to initialize the AMD IOMMU driver,
+ * and all resources are freed.
+ */
+ init_state = IOMMU_RESOURCE_FREE;
#ifdef CONFIG_GART_IOMMU
/*
- * We failed to initialize the AMD IOMMU - try fallback to GART
- * if possible.
+ * try fallback to GART if possible.
*/
gart_iommu_init();
@@ -2583,6 +2593,8 @@ static int amd_iommu_enable_interrupts(void)
}
out:
+ if (ret)
+ pr_err("AMD-Vi: Failed to enable IOMMU interrupts.\n");
return ret;
}
@@ -2665,6 +2677,7 @@ static int __init state_next(void)
break;
case IOMMU_NOT_FOUND:
case IOMMU_INIT_ERROR:
+ case IOMMU_RESOURCE_FREE:
case IOMMU_CMDLINE_DISABLED:
/* Error states => do nothing */
ret = -EINVAL;
@@ -2684,6 +2697,7 @@ static int __init iommu_go_to_state(enum iommu_init_state
state)
while (init_state != state) {
if (init_state == IOMMU_NOT_FOUND ||
init_state == IOMMU_INIT_ERROR ||
+ init_state == IOMMU_RESOURCE_FREE ||
init_state == IOMMU_CMDLINE_DISABLED)
break;
ret = state_next();
@@ -2747,6 +2761,7 @@ static int __init amd_iommu_init(void)
ret = iommu_go_to_state(IOMMU_INITIALIZED);
if (ret) {
+ amd_iommu_uninit_api();
free_dma_resources();
if (!irq_remapping_enabled) {
disable_iommus();
diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index 640c286..7d81254 100644
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -32,6 +32,8 @@ extern int amd_iommu_init_devices(void);
extern void amd_iommu_uninit_devices(void);
extern void amd_iommu_init_notifier(void);
extern int amd_iommu_init_api(void);
+extern void amd_iommu_uninit_api(void);
+extern bool amd_iommu_failed_initialize(void);
/* Needed for interrupt remapping */
extern int amd_iommu_prepare(void);
--
2.7.4
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