[PATCH v8 10/10] iommu/vt-d: Use old irte in kdump kernel

From: Li, Zhen-Hua
Date: Mon Jan 12 2015 - 02:09:40 EST


Fix the intr-remapping fault.

[1.594890] dmar: DRHD: handling fault status reg 2
[1.594894] dmar: INTR-REMAP: Request device [[41:00.0] fault index 4d
[1.594894] INTR-REMAP:[fault reason 34] Present field in the IRTE entry
is clear

Use old irte in kdump kernel, do not disable and re-enable interrupt
remapping.

Signed-off-by: Li, Zhen-Hua <zhen-hual@xxxxxx>
---
drivers/iommu/intel_irq_remapping.c | 42 ++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index d37fd62..58356cb 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -198,6 +198,11 @@ static int modify_irte(int irq, struct irte *irte_modified)

set_64bit(&irte->low, irte_modified->low);
set_64bit(&irte->high, irte_modified->high);
+
+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel())
+ __iommu_update_old_irte(iommu, index);
+#endif
__iommu_flush_cache(iommu, irte, sizeof(*irte));

rc = qi_flush_iec(iommu, index, 0);
@@ -259,6 +264,11 @@ static int clear_entries(struct irq_2_iommu *irq_iommu)
bitmap_release_region(iommu->ir_table->bitmap, index,
irq_iommu->irte_mask);

+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel())
+ __iommu_update_old_irte(iommu, -1);
+#endif
+
return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
}

@@ -640,11 +650,20 @@ static int __init intel_enable_irq_remapping(void)
*/
dmar_fault(-1, iommu);

- /*
- * Disable intr remapping and queued invalidation, if already
- * enabled prior to OS handover.
- */
- iommu_disable_irq_remapping(iommu);
+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel()) {
+ /* Do notdisable irq and then re-enable again. */
+ } else {
+#endif
+ /*
+ * Disable intr remapping and queued invalidation,
+ * if already enabled prior to OS handover.
+ */
+ iommu_disable_irq_remapping(iommu);
+
+#ifdef CONFIG_CRASH_DUMP
+ }
+#endif

dmar_disable_qi(iommu);
}
@@ -687,7 +706,20 @@ static int __init intel_enable_irq_remapping(void)
if (intel_setup_irq_remapping(iommu))
goto error;

+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel()) {
+ unsigned long long q;
+
+ q = dmar_readq(iommu->reg + DMAR_IRTA_REG);
+ iommu->ir_table->base_old_phys = q & VTD_PAGE_MASK;
+ iommu->ir_table->base_old_virt = ioremap_cache(
+ iommu->ir_table->base_old_phys,
+ INTR_REMAP_TABLE_ENTRIES*sizeof(struct irte));
+ __iommu_load_old_irte(iommu);
+ } else
+#endif
iommu_set_irq_remapping(iommu, eim);
+
setup = 1;
}

--
2.0.0-rc0

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