Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752241AbaDYAi1 (ORCPT ); Thu, 24 Apr 2014 20:38:27 -0400 Received: from g2t1383g.austin.hp.com ([15.217.136.92]:20582 "EHLO g2t1383g.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751541AbaDYAiY (ORCPT ); Thu, 24 Apr 2014 20:38:24 -0400 From: Bill Sumner To: dwmw2@infradead.org, indou.takao@jp.fujitsu.com, bhe@redhat.com, joro@8bytes.org Cc: iommu@lists.linux-foundation.org, kexec@lists.infradead.org, alex.williamson@redhat.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ddutile@redhat.com, ishii.hironobu@jp.fujitsu.com, bhelgaas@google.com, bill.sumner@hp.com, doug.hatch@hp.com, zhenhua@hp.com, jerry.hoemann@hp.com Subject: [PATCH 8/8] iommu/vt-d: Changes to support kdump Date: Thu, 24 Apr 2014 18:36:38 -0600 Message-Id: <1398386198-19304-9-git-send-email-bill.sumner@hp.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1398386198-19304-1-git-send-email-bill.sumner@hp.com> References: <1398386198-19304-1-git-send-email-bill.sumner@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add "#include " to gain access to is_kdump_kernel() Modify the operation of the following functions when called during crash dump: device_to_domain_id get_domain_for_dev init_dmars intel_iommu_init Signed-off-by: Bill Sumner --- drivers/iommu/intel-iommu.c | 133 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 120 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 226c1d0..8b3e509 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -46,6 +46,7 @@ #include "irq_remapping.h" #include "pci.h" #include "intel-iommu-private.h" +#include static LIST_HEAD(dmar_atsr_units); static LIST_HEAD(dmar_rmrr_units); @@ -53,6 +54,7 @@ static LIST_HEAD(dmar_rmrr_units); #define for_each_rmrr_units(rmrr) \ list_for_each_entry(rmrr, &dmar_rmrr_units, list) +static int intel_iommu_in_crashdump; static void __init check_tylersburg_isoch(void); @@ -1796,6 +1798,24 @@ 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 device->archdata.iommu stores the info @@ -1880,6 +1900,9 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) unsigned long flags; u8 bus, devfn, bridge_bus, bridge_devfn; 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(dev); if (domain) @@ -1920,6 +1943,24 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) domain = alloc_domain(false); if (!domain) goto error; + +#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, bus, 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 */ + if (iommu_attach_domain(domain, iommu, did)) { free_domain_mem(domain); domain = NULL; @@ -1929,6 +1970,18 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) if (domain_init(domain, 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) { domain = dmar_insert_dev_info(iommu, bridge_bus, bridge_devfn, @@ -2331,6 +2384,10 @@ static int __init init_dmars(void) struct device *dev; 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 @@ -2374,16 +2431,40 @@ static int __init init_dmars(void) if (ret) goto free_iommu; - /* - * 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 free_iommu; +#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 free_iommu; + } +#ifdef CONFIG_CRASH_DUMP } +#endif /* CONFIG_CRASH_DUMP */ + if (!ecap_pass_through(iommu->ecap)) hw_pass_through = 0; } @@ -2442,6 +2523,16 @@ static int __init init_dmars(void) check_tylersburg_isoch(); +#ifdef CONFIG_CRASH_DUMP + /* + * 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 (intel_iommu_in_crashdump) + goto skip_new_domains_for_si_rmrr_isa; +#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 @@ -2482,6 +2573,10 @@ static int __init init_dmars(void) iommu_prepare_isa(); +#ifdef CONFIG_CRASH_DUMP +skip_new_domains_for_si_rmrr_isa:; +#endif /* CONFIG_CRASH_DUMP */ + /* * for each drhd * enable fault log @@ -3624,12 +3719,24 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/