[PATCH 3/6] Crashdump-Accepting-Active-IOMMU-Domain-Interfaces
Bill Sumner
bill.sumner at hp.com
Tue Dec 3 14:41:31 EST 2013
Signed-off-by: Bill Sumner <bill.sumner at hp.com>
---
drivers/iommu/intel-iommu.c | 266 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 266 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index b68b962..ee68f42 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4527,3 +4527,269 @@ static int oldcopy(void *to, void *from, int size)
return (int) ret;
}
#endif /* CONFIG_CRASH_DUMP */
+#ifdef CONFIG_CRASH_DUMP
+
+
+
+/* ------------------------------------------------------------------------
+ * Interfaces for when a new domain in the new kernel needs some values
+ * from the old kernel's context entries
+ * ------------------------------------------------------------------------
+ */
+
+/* List to hold domain values found during the copy operation */
+static struct list_head *device_domain_values_list;
+
+
+/* Utility function for interface functions that follow. */
+static int
+context_get_entry(struct context_entry *context_addr,
+ struct intel_iommu *iommu, u32 bus, int devfn)
+{
+ unsigned long long q; /* quadword scratch */
+ struct root_entry *root_phys; /* Phys adr (root table entry) */
+ struct root_entry root_temp; /* Local copy of root_entry */
+ struct context_entry *context_phys; /* Phys adr */
+
+ if (pr_dbg.domain_get)
+ pr_debug("ENTER %s B:D:F=%2.2x:%2.2x:%1.1x &context_entry:0x%llx &intel_iommu:0x%llx\n",
+ __func__, bus, devfn>>3, devfn&7,
+ (u64)context_addr, (u64)iommu);
+
+ if (bus > 255) /* Sanity check */
+ return -5;
+ if (devfn > 255 || devfn < 0) /* Sanity check */
+ return -6;
+
+ q = readq(iommu->reg + DMAR_RTADDR_REG);
+ pr_debug("IOMMU %d: DMAR_RTADDR_REG:0x%16.16llx\n", iommu->seq_id, q);
+ if (!q)
+ return -1;
+
+ root_phys = (struct root_entry *) q; /* Adr(base of vector) */
+ root_phys += bus; /* Adr(entry we want) */
+
+ oldcopy(&root_temp, root_phys, sizeof(root_temp));
+
+ pr_debug("root_temp.val:0x%llx .rsvd1:0x%llx root_phys:0x%llx\n",
+ root_temp.val, root_temp.rsvd1, (u64)root_phys);
+
+ if (!root_present(&root_temp))
+ return -2;
+
+ pr_debug("B:D:F=%2.2x:%2.2x:%1.1x root_temp.val: %llx .rsvd1: %llx\n",
+ bus, devfn >> 3, devfn & 7, root_temp.val, root_temp.rsvd1);
+
+ if (root_temp.rsvd1) /* If (root_entry is bad) */
+ return -3;
+
+ context_phys = get_context_phys_from_root(&root_temp);
+ if (!context_phys)
+ return -4;
+
+ context_phys += devfn; /* Adr(context_entry we want) */
+
+
+ oldcopy(context_addr, context_phys, sizeof(*context_addr));
+
+ if (pr_dbg.domain_get)
+ pr_debug("LEAVE %s returning: phys:0x%12.12llx hi:0x%16.16llx lo:0x%16.16llx\n",
+ __func__, (u64) context_phys,
+ context_addr->hi, context_addr->lo);
+ return 0;
+}
+
+
+/* Get address_width of iova for a device from old kernel (if device existed) */
+static int
+domain_get_gaw_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev)
+{
+ int ret;
+ struct context_entry context_temp;
+
+ if (pr_dbg.domain_get)
+ pr_debug("ENTER %s B:D:F=%2.2x:%2.2x:%1.1x iommu:%d\n",
+ __func__, pdev->bus->number,
+ pdev->devfn >> 3, pdev->devfn & 7,
+ iommu->seq_id);
+
+ ret = context_get_entry(&context_temp, iommu,
+ pdev->bus->number, pdev->devfn);
+ if (ret < 0)
+ return ret;
+
+ return (int) agaw_to_width(context_get_aw(&context_temp));
+}
+
+
+/* Get domain_id for a device from old kernel (if device existed) */
+static int
+domain_get_did_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev)
+{
+ int ret;
+ struct context_entry context_temp;
+
+ if (pr_dbg.domain_get)
+ pr_debug("ENTER %s B:D:F=%2.2x:%2.2x:%1.1x iommu:%d\n",
+ __func__, pdev->bus->number,
+ pdev->devfn >> 3, pdev->devfn & 7,
+ iommu->seq_id);
+
+ ret = context_get_entry(&context_temp, iommu,
+ pdev->bus->number, pdev->devfn);
+ if (ret < 0)
+ return ret;
+
+ return (int) context_get_did(&context_temp);
+}
+
+
+/* Get adr(top page_table) for a device from old kernel (if device exists) */
+static u64
+domain_get_pgd_from_old_kernel(struct intel_iommu *iommu, struct pci_dev *pdev)
+{
+ int ret;
+ struct context_entry context_temp;
+ u64 phys;
+ u64 virt;
+
+ if (pr_dbg.domain_get)
+ pr_debug("ENTER %s B:D:F=%2.2x:%2.2x:%1.1x iommu:%d\n",
+ __func__, pdev->bus->number,
+ pdev->devfn >> 3, pdev->devfn & 7,
+ iommu->seq_id);
+
+ ret = context_get_entry(&context_temp, iommu,
+ pdev->bus->number, pdev->devfn);
+ if (ret < 0)
+ return 0;
+ if (!context_get_p(&context_temp))
+ return 0;
+
+ phys = context_get_asr(&context_temp) << VTD_PAGE_SHIFT;
+ if (pr_dbg.domain_get)
+ pr_debug("%s, phys: 0x%16.16llx\n", __func__, (u64) phys);
+
+ if (!phys)
+ return 0;
+
+ virt = (u64) phys_to_virt(phys);
+ if (pr_dbg.domain_get)
+ pr_debug("%s, virt: 0x%16.16llx\n", __func__, (u64) virt);
+
+ return virt;
+}
+
+
+/* Mark IOVAs that are in-use at time of panic by a device of the old kernel.
+ * Mark IOVAs in the domain for that device in the new kernel
+ * so that all new requests from the device driver for an IOVA will avoid
+ * re-using any IOVA that was in-use by the old kernel.
+ */
+static void
+domain_get_ranges_from_old_kernel(struct dmar_domain *domain,
+ struct intel_iommu *iommu,
+ struct pci_dev *pdev)
+{
+ u32 bus = pdev->bus->number;
+ int devfn = pdev->devfn;
+ struct device_domain_info *i = NULL; /* iterator for foreach */
+
+ pr_debug("ENTER %s, iommu=%d, B:D:F=%2.2x:%2.2x:%1.1x\n",
+ __func__, iommu->seq_id,
+ bus, devfn >> 3, devfn & 0x3);
+
+ list_for_each_entry(i, &device_domain_values_list[iommu->seq_id],
+ global) {
+ if (i->bus == bus && i->devfn == devfn) {
+ if (i->domain == NULL) {
+ pr_err("ERROR %s, iommu=%d, B:D:F=%2.2x:%2.2x:%1.1x\n",
+ __func__, iommu->seq_id,
+ bus, devfn >> 3, devfn & 0x3);
+
+ pr_err("FOUND B:D:F=%2.2x:%2.2x:%1.1x INFO domain-pointer is NULL\n",
+ bus, devfn >> 3, devfn & 0x3);
+ break;
+ }
+ pr_debug("FOUND B:D:F=%2.2x:%2.2x:%1.1x did:%4.4x\n",
+ bus, devfn >> 3, devfn & 0x3, i->domain->id);
+
+ copy_reserved_iova(&i->domain->iovad, &domain->iovad);
+ break;
+ }
+ }
+
+ pr_debug("LEAVE %s\n", __func__);
+}
+
+
+/* Mark domain-id's from old kernel as in-use on this iommu so that a new
+ * domain-id is allocated in the case where there is a device in the new kernel
+ * that was not in the old kernel -- and therefore a new domain-id is needed.
+ */
+static int intel_iommu_get_dids_from_old_kernel(struct intel_iommu *iommu)
+{
+ unsigned long long q; /* quadword scratch */
+ struct root_entry *root_phys; /* Phys(in old kernel) */
+ struct root_entry *root_temp; /* Virt(Local copy) */
+ struct root_entry *re; /* Loop index */
+ struct context_entry *context_phys; /* Phys(in old kernel) */
+ struct context_entry *context_temp; /* Virt(Local copy) */
+ struct context_entry *ce; /* Loop index */
+ int did; /* Each domain-id found */
+ u32 bus; /* Index into root-entry-table */
+ u32 devfn; /* Index into context-entry-table */
+
+ pr_debug("ENTER %s iommu:%d\n", __func__, iommu->seq_id);
+
+ q = readq(iommu->reg + DMAR_RTADDR_REG);
+ pr_debug("IOMMU %d: DMAR_RTADDR_REG:0x%16.16llx\n", iommu->seq_id, q);
+ if (!q)
+ return -ENOMEM;
+
+ root_phys = (void *)q;
+ root_temp = (struct root_entry *)alloc_pgtable_page(iommu->node);
+ if (!root_temp)
+ return -ENOMEM;
+ oldcopy(root_temp, root_phys, PAGE_SIZE);
+
+ context_temp = (struct context_entry *)alloc_pgtable_page(iommu->node);
+ if (!context_temp) {
+ free_pgtable_page(root_temp);
+ return -ENOMEM;
+ }
+
+ for (bus = 0, re = root_temp; bus < 256; bus += 1, re += 1) {
+
+ if (!root_present(re))
+ continue;
+
+ pr_debug("ROOT B:%2.2x val: %16.16llx rsvd1: %16.16llx\n",
+ bus, re->val, re->rsvd1);
+
+ if (re->rsvd1) /* If (root_entry is bad) */
+ continue;
+
+ context_phys = get_context_phys_from_root(re);
+ if (!context_phys)
+ continue;
+
+ oldcopy(context_temp, context_phys, PAGE_SIZE);
+
+ for (devfn = 0, ce = context_temp; devfn < 512; devfn++, ce++) {
+ if (!context_get_p(ce))
+ continue;
+
+ did = context_get_did(ce);
+ set_bit(did, iommu->domain_ids);
+ pr_debug("DID B:D:F:%2.2x:%2.2x:%1.1x did:%d(0x%4.4x)\n",
+ bus, devfn >> 3, devfn & 0x7, did, did);
+ }
+
+ }
+ free_pgtable_page(root_temp);
+ free_pgtable_page(context_temp);
+ pr_debug("LEAVE %s iommu:%d\n", __func__, iommu->seq_id);
+ return 0;
+}
+#endif /* CONFIG_CRASH_DUMP */
--
Bill Sumner <bill.sumner at hp.com>
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