Items needed for fixing crashdump.
Signed-off-by: Bill Sumner <bill.sumner@xxxxxx>
---
drivers/iommu/intel-iommu-private.h | 92 +++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/drivers/iommu/intel-iommu-private.h b/drivers/iommu/intel-iommu-private.h
index 73dabec..b436cd8 100644
--- a/drivers/iommu/intel-iommu-private.h
+++ b/drivers/iommu/intel-iommu-private.h
@@ -349,3 +349,95 @@ static inline void free_pgtable_page(void *vaddr)
free_page((unsigned long)vaddr);
}
+#ifdef CONFIG_CRASH_DUMP
+/*
+ * Fix Crashdump failure caused by leftover DMA through a hardware IOMMU
+ *
+ * Fixes the crashdump kernel to deal with an active iommu and legacy
+ * DMA from the (old) panicked kernel in a manner similar to how legacy
+ * DMA is handled when no hardware iommu was in use by the old kernel --
+ * allow the legacy DMA to continue into its current buffers.
+ *
+ * In the crashdump kernel, this code:
+ * 1. skips disabling the IOMMU's translating of IO Virtual Addresses (IOVA)
+ * 2. leaves the current translations in-place so that legacy DMA will
+ * continue to use its current buffers,
+ * 3. allocates to the device drivers in the crashdump kernel
+ * portions of the iova address ranges that are different
+ * from the iova address ranges that were being used by the old kernel
+ * at the time of the panic.
+ *
+ */
+
+struct domain_values_entry {
+ struct list_head link; /* link entries into a list */
+ struct iova_domain iovad; /* iova's that belong to this domain */
+ struct dma_pte *pgd; /* virtual address */
+ int did; /* domain id */
+ int gaw; /* max guest address width */
+ int iommu_superpage; /* Level of superpages supported:
+ 0 == 4KiB (no superpages), 1 == 2MiB,
+ 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
+};
+
+
+
+/* ------------------------------------------------------------------------
+ * Prototypes of interface functions
+ * ------------------------------------------------------------------------
+ */
+
+extern int
+intel_iommu_copy_translation_tables(struct dmar_drhd_unit *drhd,
+ struct root_entry **root_old_p, struct root_entry **root_new_p,
+ int g_num_of_iommus);
+
+extern int
+intel_iommu_get_dids_from_old_kernel(struct intel_iommu *iommu);
+
+extern struct domain_values_entry *
+intel_iommu_did_to_domain_values_entry(int did, struct intel_iommu *iommu);
+
+
+/* ------------------------------------------------------------------------
+ * Utility functions for accessing the iommu Translation Tables
+ * ------------------------------------------------------------------------
+ */
+
+static inline struct context_entry *
+get_context_phys_from_root(struct root_entry *root)
+{
+ return (struct context_entry *)
+ (root_present(root) ? (void *) (root->val & VTD_PAGE_MASK)
+ : NULL);
+}
+
+static inline int
+context_get_p(struct context_entry *c) {return((c->lo >> 0) & 0x1); }
+
+static inline int
+context_get_fpdi(struct context_entry *c) {return((c->lo >> 1) & 0x1); }
+
+static inline int
+context_get_t(struct context_entry *c) {return((c->lo >> 2) & 0x3); }
+
+static inline u64
+context_get_asr(struct context_entry *c) {return((c->lo >> 12)); }
+
+static inline int
+context_get_aw(struct context_entry *c) {return((c->hi >> 0) & 0x7); }
+
+static inline int
+context_get_aval(struct context_entry *c) {return((c->hi >> 3) & 0xf); }
+
+static inline int
+context_get_did(struct context_entry *c) {return((c->hi >> 8) & 0xffff); }
+
+static inline void
+context_put_asr(struct context_entry *c, unsigned long asr)
+{
+ c->lo &= (~VTD_PAGE_MASK);
+ c->lo |= (asr << VTD_PAGE_SHIFT);
+}
+
+#endif /* CONFIG_CRASH_DUMP */
--
Bill Sumner <bill.sumner@xxxxxx>
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