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
28void 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 */
51static 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: end - 1, ih: 0);
68}
69
70static 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: dev_pasid->dev);
92 intel_pasid_tear_down_entry(iommu: info->iommu, dev: dev_pasid->dev,
93 pasid: dev_pasid->pasid, fault_ignore: true);
94 }
95 spin_unlock_irqrestore(lock: &domain->lock, flags);
96
97}
98
99static 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(objp: domain->qi_batch);
104 kfree(objp: domain);
105}
106
107static 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
113static 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
148static 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(ptr: dev_pasid))
165 return PTR_ERR(ptr: dev_pasid);
166
167 ret = iopf_for_domain_replace(new: 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, pgd: mm->pgd,
175 flags: sflags, old);
176 if (ret)
177 goto out_unwind_iopf;
178
179 domain_remove_dev_pasid(domain: old, dev, pasid);
180
181 return 0;
182out_unwind_iopf:
183 iopf_for_domain_replace(new: old, old: domain, dev);
184out_remove_dev_pasid:
185 domain_remove_dev_pasid(domain, dev, pasid);
186 return ret;
187}
188
189static void intel_svm_domain_free(struct iommu_domain *domain)
190{
191 struct dmar_domain *dmar_domain = to_dmar_domain(dom: domain);
192
193 /* dmar_domain free is deferred to the mmu free_notifier callback. */
194 mmu_notifier_put(subscription: &dmar_domain->notifier);
195}
196
197static 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
202struct 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(error: ret);
211
212 domain = kzalloc(sizeof(*domain), GFP_KERNEL);
213 if (!domain)
214 return ERR_PTR(error: -ENOMEM);
215
216 domain->domain.ops = &intel_svm_domain_ops;
217 domain->use_first_level = true;
218 INIT_LIST_HEAD(list: &domain->dev_pasids);
219 INIT_LIST_HEAD(list: &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(subscription: &domain->notifier, mm);
225 if (ret) {
226 kfree(objp: domain);
227 return ERR_PTR(error: ret);
228 }
229
230 return &domain->domain;
231}
232

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source code of linux/drivers/iommu/intel/svm.c