Signed-off-by: Bill Sumner <bill.sumner@xxxxxx>
---
drivers/iommu/intel-iommu.c | 75 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 15e9b57..a0e8a76 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -48,6 +48,7 @@
#include "irq_remapping.h"
#include "pci.h"
+#include <linux/crash_dump.h>
#define ROOT_SIZE VTD_PAGE_SIZE
#define CONTEXT_SIZE VTD_PAGE_SIZE
@@ -164,6 +165,80 @@ static inline unsigned long virt_to_dma_pfn(void *p)
return page_to_dma_pfn(virt_to_page(p));
}
+#ifdef CONFIG_CRASH_DUMP
+/* ===================================================================
+ * Crashdump Accepting Active IOMMU
+ * Enhances the crashdump kernel to deal with an active iommu
+ * and legacy DMA from the (old) panic'd 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.
+ *
+ * This code:
+ * 1. accepts the iommu hardware in an active state from the old kernel,
+ * 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.
+ * -------------------------------------------------------------------
+ */
+
+/* Flags for Crashdump Accepting Active IOMMU */
+
+static int crashdump_accepting_active_iommu; /* activate this feature */
+static int intel_iommu_translation_tables_are_mapped; /* table copy done */
+
+static struct { /* run-time pr_debug() flags */
+ unsigned in_crashdump:1; /* if crashdump_accepting_active_iommu */
+ unsigned domain_get:1; /* pr_debug in domain_get* functions */
+ unsigned copy_page_table:1; /* enter/leave copy_page_table() */
+ unsigned copy_page_addr:1; /* enter/leave copy_page_addr() */
+ unsigned addr_ranges:1; /* accumulated addr ranges */
+ unsigned reserved_ranges:1; /* accumulated addr ranges reserved */
+ unsigned page_addr:1; /* adr(each page table) */
+ unsigned enter_oldcopy:1; /* enter oldcopy() parameters */
+ unsigned leave_oldcopy:1; /* leave oldcopy() parameters */
+} pr_dbg = { /* Enable flags below here */
+ .in_crashdump = 1,
+ .domain_get = 1,
+ .copy_page_table = 1,
+ .copy_page_addr = 0,
+ .addr_ranges = 0,
+ .reserved_ranges = 0,
+ .page_addr = 0,
+ .enter_oldcopy = 0,
+ .leave_oldcopy = 0,
+};
+
+/* Prototypes of interface functions for Crashdump Accepting Active IOMMU */
+
+static int
+copy_intel_iommu_translation_tables(struct dmar_drhd_unit *drhd,
+ struct root_entry **root_old_p, struct root_entry **root_new_p);
+
+static int
+domain_get_did_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev);
+
+static int
+domain_get_gaw_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev);
+
+static u64
+domain_get_pgd_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev);
+
+static void
+domain_get_ranges_from_old_kernel(struct dmar_domain *domain,
+ struct intel_iommu *iommu, struct pci_dev *pdev);
+static int
+intel_iommu_get_dids_from_old_kernel(struct intel_iommu *iommu);
+
+/* Debug-print functions for Crashdump Accepting Active IOMMU */
+
+static void
+print_intel_iommu_registers(struct dmar_drhd_unit *drhd);
+#endif /* CONFIG_CRASH_DUMP */
+
+
/* global iommu list, set NULL for ignored DMAR units */
static struct intel_iommu **g_iommus;
--
Bill Sumner <bill.sumner@xxxxxx>
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