1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright © 2015 Intel Corporation. 4 * 5 * Authors: David Woodhouse <dwmw2@infradead.org> 6 */ 7 8 #include <linux/mmu_notifier.h> 9 #include <linux/sched.h> 10 #include <linux/sched/mm.h> 11 #include <linux/slab.h> 12 #include <linux/rculist.h> 13 #include <linux/pci.h> 14 #include <linux/pci-ats.h> 15 #include <linux/dmar.h> 16 #include <linux/interrupt.h> 17 #include <linux/mm_types.h> 18 #include <linux/xarray.h> 19 #include <asm/page.h> 20 #include <asm/fpu/api.h> 21 22 #include "iommu.h" 23 #include "pasid.h" 24 #include "perf.h" 25 #include "../iommu-pages.h" 26 #include "trace.h" 27 28 void intel_svm_check(struct intel_iommu *iommu) 29 { 30 if (!pasid_supported(iommu)) 31 return; 32 33 if (cpu_feature_enabled(X86_FEATURE_GBPAGES) && 34 !cap_fl1gp_support(iommu->cap)) { 35 pr_err("%s SVM disabled, incompatible 1GB page capability\n", 36 iommu->name); 37 return; 38 } 39 40 if (cpu_feature_enabled(X86_FEATURE_LA57) && 41 !cap_fl5lp_support(iommu->cap)) { 42 pr_err("%s SVM disabled, incompatible paging mode\n", 43 iommu->name); 44 return; 45 } 46 47 iommu->flags |= VTD_FLAG_SVM_CAPABLE; 48 } 49 50 /* Pages have been freed at this point */ 51 static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn, 52 struct mm_struct *mm, 53 unsigned long start, unsigned long end) 54 { 55 struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier); 56 57 if (start == 0 && end == ULONG_MAX) { 58 cache_tag_flush_all(domain); 59 return; 60 } 61 62 /* 63 * The mm_types defines vm_end as the first byte after the end address, 64 * different from IOMMU subsystem using the last address of an address 65 * range. 66 */ 67 cache_tag_flush_range(domain, start, end - 1, 0); 68 } 69 70 static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) 71 { 72 struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier); 73 struct dev_pasid_info *dev_pasid; 74 struct device_domain_info *info; 75 unsigned long flags; 76 77 /* This might end up being called from exit_mmap(), *before* the page 78 * tables are cleared. And __mmu_notifier_release() will delete us from 79 * the list of notifiers so that our invalidate_range() callback doesn't 80 * get called when the page tables are cleared. So we need to protect 81 * against hardware accessing those page tables. 82 * 83 * We do it by clearing the entry in the PASID table and then flushing 84 * the IOTLB and the PASID table caches. This might upset hardware; 85 * perhaps we'll want to point the PASID to a dummy PGD (like the zero 86 * page) so that we end up taking a fault that the hardware really 87 * *has* to handle gracefully without affecting other processes. 88 */ 89 spin_lock_irqsave(&domain->lock, flags); 90 list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) { 91 info = dev_iommu_priv_get(dev_pasid->dev); 92 intel_pasid_tear_down_entry(info->iommu, dev_pasid->dev, 93 dev_pasid->pasid, true); 94 } 95 spin_unlock_irqrestore(&domain->lock, flags); 96 97 } 98 99 static void intel_mm_free_notifier(struct mmu_notifier *mn) 100 { 101 struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier); 102 103 kfree(domain->qi_batch); 104 kfree(domain); 105 } 106 107 static const struct mmu_notifier_ops intel_mmuops = { 108 .release = intel_mm_release, 109 .arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs, 110 .free_notifier = intel_mm_free_notifier, 111 }; 112 113 static int intel_iommu_sva_supported(struct device *dev) 114 { 115 struct device_domain_info *info = dev_iommu_priv_get(dev); 116 struct intel_iommu *iommu; 117 118 if (!info || dmar_disabled) 119 return -EINVAL; 120 121 iommu = info->iommu; 122 if (!iommu) 123 return -EINVAL; 124 125 if (!(iommu->flags & VTD_FLAG_SVM_CAPABLE)) 126 return -ENODEV; 127 128 if (!info->pasid_enabled || !info->ats_enabled) 129 return -EINVAL; 130 131 /* 132 * Devices having device-specific I/O fault handling should not 133 * support PCI/PRI. The IOMMU side has no means to check the 134 * capability of device-specific IOPF. Therefore, IOMMU can only 135 * default that if the device driver enables SVA on a non-PRI 136 * device, it will handle IOPF in its own way. 137 */ 138 if (!info->pri_supported) 139 return 0; 140 141 /* Devices supporting PRI should have it enabled. */ 142 if (!info->pri_enabled) 143 return -EINVAL; 144 145 return 0; 146 } 147 148 static int intel_svm_set_dev_pasid(struct iommu_domain *domain, 149 struct device *dev, ioasid_t pasid, 150 struct iommu_domain *old) 151 { 152 struct device_domain_info *info = dev_iommu_priv_get(dev); 153 struct intel_iommu *iommu = info->iommu; 154 struct mm_struct *mm = domain->mm; 155 struct dev_pasid_info *dev_pasid; 156 unsigned long sflags; 157 int ret = 0; 158 159 ret = intel_iommu_sva_supported(dev); 160 if (ret) 161 return ret; 162 163 dev_pasid = domain_add_dev_pasid(domain, dev, pasid); 164 if (IS_ERR(dev_pasid)) 165 return PTR_ERR(dev_pasid); 166 167 ret = iopf_for_domain_replace(domain, old, dev); 168 if (ret) 169 goto out_remove_dev_pasid; 170 171 /* Setup the pasid table: */ 172 sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; 173 ret = __domain_setup_first_level(iommu, dev, pasid, 174 FLPT_DEFAULT_DID, mm->pgd, 175 sflags, old); 176 if (ret) 177 goto out_unwind_iopf; 178 179 domain_remove_dev_pasid(old, dev, pasid); 180 181 return 0; 182 out_unwind_iopf: 183 iopf_for_domain_replace(old, domain, dev); 184 out_remove_dev_pasid: 185 domain_remove_dev_pasid(domain, dev, pasid); 186 return ret; 187 } 188 189 static void intel_svm_domain_free(struct iommu_domain *domain) 190 { 191 struct dmar_domain *dmar_domain = to_dmar_domain(domain); 192 193 /* dmar_domain free is deferred to the mmu free_notifier callback. */ 194 mmu_notifier_put(&dmar_domain->notifier); 195 } 196 197 static const struct iommu_domain_ops intel_svm_domain_ops = { 198 .set_dev_pasid = intel_svm_set_dev_pasid, 199 .free = intel_svm_domain_free 200 }; 201 202 struct iommu_domain *intel_svm_domain_alloc(struct device *dev, 203 struct mm_struct *mm) 204 { 205 struct dmar_domain *domain; 206 int ret; 207 208 ret = intel_iommu_sva_supported(dev); 209 if (ret) 210 return ERR_PTR(ret); 211 212 domain = kzalloc(sizeof(*domain), GFP_KERNEL); 213 if (!domain) 214 return ERR_PTR(-ENOMEM); 215 216 domain->domain.ops = &intel_svm_domain_ops; 217 domain->use_first_level = true; 218 INIT_LIST_HEAD(&domain->dev_pasids); 219 INIT_LIST_HEAD(&domain->cache_tags); 220 spin_lock_init(&domain->cache_lock); 221 spin_lock_init(&domain->lock); 222 223 domain->notifier.ops = &intel_mmuops; 224 ret = mmu_notifier_register(&domain->notifier, mm); 225 if (ret) { 226 kfree(domain); 227 return ERR_PTR(ret); 228 } 229 230 return &domain->domain; 231 } 232