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Message-Id: <1397603349-30930-9-git-send-email-bill.sumner@hp.com>
Date: Tue, 15 Apr 2014 17:09:09 -0600
From: Bill Sumner <bill.sumner@...com>
To: dwmw2@...radead.org, indou.takao@...fujitsu.com, bhe@...hat.com,
joro@...tes.org
Cc: iommu@...ts.linux-foundation.org, kexec@...ts.infradead.org,
alex.williamson@...hat.com, linux-pci@...r.kernel.org,
linux-kernel@...r.kernel.org, ddutile@...hat.com,
ishii.hironobu@...fujitsu.com, bhelgaas@...gle.com,
bill.sumner@...com, doug.hatch@...com, zhenhua@...com
Subject: [PATCH 8/8] Add remaining changes to intel-iommu.c to fix crashdump
Add "#include <linux/crash_dump.h>"
Chg device_to_domain_id
Chg get_domain_for_dev
Chg init_dmars
Chg intel_iommu_init
Signed-off-by: Bill Sumner <bill.sumner@...com>
---
drivers/iommu/intel-iommu.c | 210 +++++++++++++++++++++++++++++++++-----------
1 file changed, 158 insertions(+), 52 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0c00c2d..a8d8489 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -49,7 +49,9 @@
#include "irq_remapping.h"
#include "pci.h"
#include "intel-iommu-private.h"
+#include <linux/crash_dump.h>
+static int intel_iommu_in_crashdump;
static void __init check_tylersburg_isoch(void);
@@ -1605,6 +1607,24 @@ static void domain_remove_dev_info(struct dmar_domain *domain)
spin_unlock_irqrestore(&device_domain_lock, flags);
}
+#ifdef CONFIG_CRASH_DUMP
+static int device_to_domain_id(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+ int did = -1; /* domain-id returned */
+ struct root_entry *root;
+ struct context_entry *context;
+ unsigned long flags;
+
+ spin_lock_irqsave(&iommu->lock, flags);
+ root = &iommu->root_entry[bus];
+ context = get_context_addr_from_root(root);
+ if (context && context_present(context+devfn))
+ did = context_get_did(context+devfn);
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ return did;
+}
+#endif /* CONFIG_CRASH_DUMP */
+
/*
* find_domain
* Note: we use struct pci_dev->dev.archdata.iommu stores the info
@@ -1634,6 +1654,9 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
int segment;
int ret;
int did = -1; /* Default to "no domain_id supplied" */
+#ifdef CONFIG_CRASH_DUMP
+ struct domain_values_entry *dve = NULL;
+#endif /* CONFIG_CRASH_DUMP */
domain = find_domain(pdev);
if (domain)
@@ -1680,6 +1703,24 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
}
iommu = drhd->iommu;
+#ifdef CONFIG_CRASH_DUMP
+ if (intel_iommu_in_crashdump) {
+ /*
+ * if this device had a did in the old kernel
+ * use its values instead of generating new ones
+ */
+ did = device_to_domain_id(iommu, pdev->bus->number,
+ pdev->devfn);
+ if (did > 0 || (did == 0 && !cap_caching_mode(iommu->cap)))
+ dve = intel_iommu_did_to_domain_values_entry(did,
+ iommu);
+ if (dve)
+ gaw = dve->gaw;
+ else
+ did = -1;
+ }
+#endif /* CONFIG_CRASH_DUMP */
+
ret = iommu_attach_domain(domain, iommu, did);
if (ret) {
free_domain_mem(domain);
@@ -1691,6 +1732,18 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
goto error;
}
+#ifdef CONFIG_CRASH_DUMP
+ if (intel_iommu_in_crashdump && dve) {
+
+ if (domain->pgd)
+ free_pgtable_page(domain->pgd);
+
+ domain->pgd = dve->pgd;
+
+ copy_reserved_iova(&dve->iovad, &domain->iovad);
+ }
+#endif /* CONFIG_CRASH_DUMP */
+
/* register pcie-to-pci device */
if (dev_tmp) {
info = alloc_devinfo_mem();
@@ -2109,6 +2162,10 @@ static int __init init_dmars(void)
struct pci_dev *pdev;
struct intel_iommu *iommu;
int i, ret;
+#ifdef CONFIG_CRASH_DUMP
+ struct root_entry *root_old_phys;
+ struct root_entry *root_new_virt;
+#endif /* CONFIG_CRASH_DUMP */
/*
* for each drhd
@@ -2152,16 +2209,40 @@ static int __init init_dmars(void)
if (ret)
goto error;
- /*
- * TBD:
- * we could share the same root & context tables
- * among all IOMMU's. Need to Split it later.
- */
- ret = iommu_alloc_root_entry(iommu);
- if (ret) {
- printk(KERN_ERR "IOMMU: allocate root entry failed\n");
- goto error;
+#ifdef CONFIG_CRASH_DUMP
+ if (intel_iommu_in_crashdump) {
+ pr_info("IOMMU Copying translate tables from panicked kernel\n");
+ ret = intel_iommu_copy_translation_tables(drhd,
+ &root_old_phys, &root_new_virt,
+ g_num_of_iommus);
+ if (ret) {
+ pr_err("IOMMU: Copy translate tables failed\n");
+
+ /* Best to stop trying */
+ intel_iommu_in_crashdump = false;
+ goto error;
+ }
+ iommu->root_entry = root_new_virt;
+ pr_info("IOMMU: root_new_virt:0x%12.12llx phys:0x%12.12llx\n",
+ (u64)root_new_virt,
+ virt_to_phys(root_new_virt));
+ intel_iommu_get_dids_from_old_kernel(iommu);
+ } else {
+#endif /* CONFIG_CRASH_DUMP */
+ /*
+ * TBD:
+ * we could share the same root & context tables
+ * among all IOMMU's. Need to Split it later.
+ */
+ ret = iommu_alloc_root_entry(iommu);
+ if (ret) {
+ printk(KERN_ERR "IOMMU: allocate root entry failed\n");
+ goto error;
+ }
+#ifdef CONFIG_CRASH_DUMP
}
+#endif /* CONFIG_CRASH_DUMP */
+
if (!ecap_pass_through(iommu->ecap))
hw_pass_through = 0;
}
@@ -2220,50 +2301,63 @@ static int __init init_dmars(void)
check_tylersburg_isoch();
+#ifdef CONFIG_CRASH_DUMP
/*
- * If pass through is not set or not enabled, setup context entries for
- * identity mappings for rmrr, gfx, and isa and may fall back to static
- * identity mapping if iommu_identity_mapping is set.
+ * In the crashdump kernel: Skip setting-up new domains for
+ * si, rmrr, and the isa bus on the expectation that these
+ * translations were copied from the old kernel.
*/
- if (iommu_identity_mapping) {
- ret = iommu_prepare_static_identity_mapping(hw_pass_through);
- if (ret) {
- printk(KERN_CRIT "Failed to setup IOMMU pass-through\n");
- goto error;
+ if (!intel_iommu_in_crashdump) {
+#endif /* CONFIG_CRASH_DUMP */
+ /*
+ * If pass through is not set or not enabled, setup context
+ * entries for identity mappings for rmrr, gfx, and isa and
+ * may fall back to static identity mapping if
+ * iommu_identity_mapping is set.
+ */
+ if (iommu_identity_mapping) {
+ ret = iommu_prepare_static_identity_mapping(
+ hw_pass_through);
+ if (ret) {
+ printk(KERN_CRIT "Failed to setup IOMMU pass-through\n");
+ goto error;
+ }
}
- }
- /*
- * For each rmrr
- * for each dev attached to rmrr
- * do
- * locate drhd for dev, alloc domain for dev
- * allocate free domain
- * allocate page table entries for rmrr
- * if context not allocated for bus
- * allocate and init context
- * set present in root table for this bus
- * init context with domain, translation etc
- * endfor
- * endfor
- */
- printk(KERN_INFO "IOMMU: Setting RMRR:\n");
- for_each_rmrr_units(rmrr) {
- for (i = 0; i < rmrr->devices_cnt; i++) {
- pdev = rmrr->devices[i];
- /*
- * some BIOS lists non-exist devices in DMAR
- * table.
- */
- if (!pdev)
- continue;
- ret = iommu_prepare_rmrr_dev(rmrr, pdev);
- if (ret)
- printk(KERN_ERR
- "IOMMU: mapping reserved region failed\n");
+ /*
+ * For each rmrr
+ * for each dev attached to rmrr
+ * do
+ * locate drhd for dev, alloc domain for dev
+ * allocate free domain
+ * allocate page table entries for rmrr
+ * if context not allocated for bus
+ * allocate and init context
+ * set present in root table for this bus
+ * init context with domain, translation etc
+ * endfor
+ * endfor
+ */
+ printk(KERN_INFO "IOMMU: Setting RMRR:\n");
+ for_each_rmrr_units(rmrr) {
+ for (i = 0; i < rmrr->devices_cnt; i++) {
+ pdev = rmrr->devices[i];
+ /*
+ * some BIOS lists non-exist devices in DMAR
+ * table.
+ */
+ if (!pdev)
+ continue;
+ ret = iommu_prepare_rmrr_dev(rmrr, pdev);
+ if (ret)
+ printk(KERN_ERR
+ "IOMMU: mapping reserved region failed\n");
+ }
}
- }
- iommu_prepare_isa();
+ iommu_prepare_isa();
+#ifdef CONFIG_CRASH_DUMP
+ }
+#endif /* CONFIG_CRASH_DUMP */
/*
* for each drhd
@@ -3325,12 +3419,24 @@ int __init intel_iommu_init(void)
goto out_free_dmar;
}
+#ifdef CONFIG_CRASH_DUMP
/*
- * Disable translation if already enabled prior to OS handover.
+ * If (This is the crash kernel)
+ * Set: copy iommu translate tables from old kernel
+ * Skip disabling the iommu hardware translations
*/
- for_each_active_iommu(iommu, drhd)
- if (iommu->gcmd & DMA_GCMD_TE)
- iommu_disable_translation(iommu);
+ if (is_kdump_kernel()) {
+ intel_iommu_in_crashdump = true;
+ pr_info("IOMMU intel_iommu_in_crashdump = true\n");
+ pr_info("IOMMU Skip disabling iommu hardware translations\n");
+ } else
+#endif /* CONFIG_CRASH_DUMP */
+ /*
+ * Disable translation if already enabled prior to OS handover.
+ */
+ for_each_active_iommu(iommu, drhd)
+ if (iommu->gcmd & DMA_GCMD_TE)
+ iommu_disable_translation(iommu);
if (dmar_dev_scope_init() < 0) {
if (force_on)
--
Bill Sumner <bill.sumner@...com>
--
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