Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754346AbaLVJRM (ORCPT ); Mon, 22 Dec 2014 04:17:12 -0500 Received: from g4t3425.houston.hp.com ([15.201.208.53]:36859 "EHLO g4t3425.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754320AbaLVJRH (ORCPT ); Mon, 22 Dec 2014 04:17:07 -0500 From: "Li, Zhen-Hua" To: , , , , , Cc: , , , , , , , , , , , , , , Subject: [PATCH 07/10] iommu/vt-d: enable kdump support in iommu module Date: Mon, 22 Dec 2014 17:15:26 +0800 Message-Id: <1419239729-26529-8-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 2.0.0-rc0 In-Reply-To: <1419239729-26529-1-git-send-email-zhen-hual@hp.com> References: <1419239729-26529-1-git-send-email-zhen-hual@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Bill Sumner: Original version. Zhenhua: Minor change, The name of new calling functions. Do not disable and re-enable TE in kdump kernel. Signed-off-by: Bill Sumner Signed-off-by: Li, Zhen-Hua --- drivers/iommu/intel-iommu.c | 142 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 125 insertions(+), 17 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index f9849cb..4efed7c 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -907,6 +907,11 @@ static struct context_entry * device_to_context_entry(struct intel_iommu *iommu, set_root_value(root, phy_addr); set_root_present(root); __iommu_flush_cache(iommu, root, sizeof(*root)); + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) + __iommu_update_old_root_entry(iommu, bus); +#endif } spin_unlock_irqrestore(&iommu->lock, flags); return &context[devfn]; @@ -958,7 +963,8 @@ static void free_context_table(struct intel_iommu *iommu) spin_lock_irqsave(&iommu->lock, flags); if (!iommu->root_entry) { - goto out; + spin_unlock_irqrestore(&iommu->lock, flags); + return; } for (i = 0; i < ROOT_ENTRY_NR; i++) { root = &iommu->root_entry[i]; @@ -966,10 +972,26 @@ static void free_context_table(struct intel_iommu *iommu) if (context) free_pgtable_page(context); } - free_pgtable_page(iommu->root_entry); - iommu->root_entry = NULL; -out: + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) { + iommu->root_entry_old_phys = 0; + root = iommu->root_entry; + iommu->root_entry = NULL; + } else { +#endif + free_pgtable_page(iommu->root_entry); + iommu->root_entry = NULL; +#ifdef CONFIG_CRASH_DUMP + } +#endif + spin_unlock_irqrestore(&iommu->lock, flags); + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) + iounmap(root); +#endif } static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, @@ -2381,6 +2403,9 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) unsigned long flags; u8 bus, 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) @@ -2414,6 +2439,24 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) domain = alloc_domain(0); if (!domain) return NULL; + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) { + /* + * 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 */ + domain->id = iommu_attach_domain(domain, iommu, did); if (domain->id < 0) { free_domain_mem(domain); @@ -2425,6 +2468,18 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw) return NULL; } +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel() && 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 PCI DMA alias device */ if (dev_is_pci(dev)) { tmp = dmar_insert_dev_info(iommu, PCI_BUS_NUM(dma_alias), @@ -2948,14 +3003,35 @@ 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) - goto free_iommu; +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) { + pr_info("IOMMU Copying translate tables from panicked kernel\n"); + ret = intel_iommu_load_translation_tables(drhd, + g_num_of_iommus); + if (ret) { + pr_err("IOMMU: Copy translate tables failed\n"); + + /* Best to stop trying */ + goto free_iommu; + } + pr_info("IOMMU: root_cache:0x%12.12llx phys:0x%12.12llx\n", + (u64)iommu->root_entry, + (u64)iommu->root_entry_old_phys); + 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) + goto free_iommu; +#ifdef CONFIG_CRASH_DUMP + } +#endif + if (!ecap_pass_through(iommu->ecap)) hw_pass_through = 0; } @@ -2972,6 +3048,16 @@ 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 (is_kdump_kernel()) + 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 @@ -3012,6 +3098,10 @@ 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 @@ -3040,7 +3130,15 @@ static int __init init_dmars(void) iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL); iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH); - iommu_enable_translation(iommu); + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) { + if (!(iommu->gcmd & DMA_GCMD_TE)) + iommu_enable_translation(iommu); + } else +#endif + iommu_enable_translation(iommu); + iommu_disable_protect_mem_regions(iommu); } @@ -4351,12 +4449,22 @@ 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()) { + 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) -- 2.0.0-rc0 -- 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/