Here several things need be done:
1) If iommu is pre-enabled in a normal kernel, just disable it and print
warning.
2) If failed to copy dev table of old kernel, continue to proceed as
it does in normal kernel.
3) Re-enable event/cmd buffer and install the new DTE table to reg.
4) Flush all caches
Signed-off-by: Baoquan He <b...@redhat.com>
---
drivers/iommu/amd_iommu_init.c | 44 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 41 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index ce49641..47a8fc9 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -34,7 +34,7 @@
#include <asm/iommu_table.h>
#include <asm/io_apic.h>
#include <asm/irq_remapping.h>
-
+#include <linux/crash_dump.h>
#include "amd_iommu_proto.h"
#include "amd_iommu_types.h"
#include "irq_remapping.h"
@@ -1344,6 +1344,12 @@ static int __init init_iommu_one(struct amd_iommu
*iommu, struct ivhd_header *h)
iommu->int_enabled = false;
init_translation_status(iommu);
+ if (translation_pre_enabled(iommu) && !is_kdump_kernel()) {
+ iommu_disable(iommu);
+ clear_translation_pre_enabled(iommu);
+ pr_warn("Translation was enabled for IOMMU:%d but we are not in
kdump mode\n",
+ iommu->index);
+ }
if (translation_pre_enabled(iommu))
pr_warn("Translation is already enabled - trying to copy
translation structures\n");
@@ -1946,9 +1952,41 @@ static void early_enable_iommu(struct amd_iommu *iommu)
static void early_enable_iommus(void)
{
struct amd_iommu *iommu;
+ bool is_pre_enabled=false;
- for_each_iommu(iommu)
- early_enable_iommu(iommu);
+ for_each_iommu(iommu) {
+ if ( translation_pre_enabled(iommu) ) {
+ is_pre_enabled = true;
+ break;
+ }
+ }
+
+ if ( !is_pre_enabled) {
+ for_each_iommu(iommu)
+ early_enable_iommu(iommu);
+ } else {
+ if (copy_dev_tables()) {
+ pr_err("Failed to copy DEV table from previous
kernel.\n");
+ /*
+ * If failed to copy dev tables from old kernel,
continue to proceed
+ * as it does in normal kernel.
+ */
+ for_each_iommu(iommu) {
+ clear_translation_pre_enabled(iommu);
+ early_enable_iommu(iommu);
+ }
+ } else {
+ pr_info("Copied DEV table from previous kernel.\n");
+ for_each_iommu(iommu) {
+ iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
+ iommu_feature_disable(iommu,
CONTROL_EVT_LOG_EN);
+ iommu_enable_command_buffer(iommu);
+ iommu_enable_event_buffer(iommu);
+ iommu_set_device_table(iommu);
+ iommu_flush_all_caches(iommu);
+ }
+ }
+ }
}
static void enable_iommus_v2(void)
--
2.5.5
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