From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752854AbbCSFhv (ORCPT ); Thu, 19 Mar 2015 01:37:51 -0400 Received: from g9t1613g.houston.hp.com ([15.240.0.71]:34717 "EHLO g9t1613g.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbbCSFhq (ORCPT ); Thu, 19 Mar 2015 01:37:46 -0400 From: "Li, Zhen-Hua" To: , , , , , Cc: , , , , , , , , , , , , , , , Subject: [PATCH v9 07/10] iommu/vt-d: enable kdump support in iommu module Date: Thu, 19 Mar 2015 13:36:25 +0800 Message-Id: <1426743388-26908-8-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 2.0.0-rc0 In-Reply-To: <1426743388-26908-1-git-send-email-zhen-hual@hp.com> References: <1426743388-26908-1-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_context_entry free_context_table get_domain_for_dev init_dmars intel_iommu_init Bill Sumner: Original version. Zhenhua: The name of new calling functions. Do not disable and re-enable TE in kdump kernel. Use the did and gaw from old context entry; Signed-off-by: Bill Sumner Signed-off-by: Li, Zhen-Hua --- drivers/iommu/intel-iommu.c | 118 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 103 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 44f3369..312f06b 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -841,6 +841,11 @@ 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]; @@ -892,7 +897,8 @@ 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]; @@ -900,10 +906,23 @@ static void free_context_table(struct intel_iommu *iommu) if (context) free_pgtable_page(context); } + +#ifdef CONFIG_CRASH_DUMP + if (is_kdump_kernel()) { + iommu->root_entry_old_phys = 0; + root = iommu->root_entry_old_virt; + iommu->root_entry_old_virt = NULL; + } +#endif free_pgtable_page(iommu->root_entry); iommu->root_entry = NULL; -out: + 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, @@ -2322,6 +2341,9 @@ 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 context_entry *ce = NULL; +#endif /* CONFIG_CRASH_DUMP */ domain = find_domain(dev); if (domain) @@ -2355,6 +2377,22 @@ 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 + */ + ce = device_to_existing_context_entry(iommu, bus, devfn); + + if (ce) { + did = context_domain_id(ce); + gaw = agaw_to_width(context_address_width(ce)); + } + } +#endif /* CONFIG_CRASH_DUMP */ + domain->id = iommu_attach_domain_with_id(domain, iommu, did); if (domain->id < 0) { free_domain_mem(domain); @@ -2889,14 +2927,33 @@ 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); + 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); + } 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; } @@ -2913,6 +2970,16 @@ 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 @@ -2953,6 +3020,10 @@ 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 @@ -2981,7 +3052,15 @@ 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); } @@ -4266,12 +4345,21 @@ 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) + * 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