xref: /linux/drivers/iommu/amd/pasid.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2024 Advanced Micro Devices, Inc.
4  */
5 
6 #define pr_fmt(fmt)     "AMD-Vi: " fmt
7 #define dev_fmt(fmt)    pr_fmt(fmt)
8 
9 #include <linux/iommu.h>
10 #include <linux/mm_types.h>
11 
12 #include "amd_iommu.h"
13 
14 static inline bool is_pasid_enabled(struct iommu_dev_data *dev_data)
15 {
16 	if (dev_data->pasid_enabled && dev_data->max_pasids &&
17 	    dev_data->gcr3_info.gcr3_tbl != NULL)
18 		return true;
19 
20 	return false;
21 }
22 
23 static inline bool is_pasid_valid(struct iommu_dev_data *dev_data,
24 				  ioasid_t pasid)
25 {
26 	if (pasid > 0 && pasid < dev_data->max_pasids)
27 		return true;
28 
29 	return false;
30 }
31 
32 static void remove_dev_pasid(struct pdom_dev_data *pdom_dev_data)
33 {
34 	/* Update GCR3 table and flush IOTLB */
35 	amd_iommu_clear_gcr3(pdom_dev_data->dev_data, pdom_dev_data->pasid);
36 
37 	list_del(&pdom_dev_data->list);
38 	kfree(pdom_dev_data);
39 }
40 
41 /* Clear PASID from device GCR3 table and remove pdom_dev_data from list */
42 static void remove_pdom_dev_pasid(struct protection_domain *pdom,
43 				  struct device *dev, ioasid_t pasid)
44 {
45 	struct pdom_dev_data *pdom_dev_data;
46 	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
47 
48 	lockdep_assert_held(&pdom->lock);
49 
50 	for_each_pdom_dev_data(pdom_dev_data, pdom) {
51 		if (pdom_dev_data->dev_data == dev_data &&
52 		    pdom_dev_data->pasid == pasid) {
53 			remove_dev_pasid(pdom_dev_data);
54 			break;
55 		}
56 	}
57 }
58 
59 static void sva_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
60 				    struct mm_struct *mm,
61 				    unsigned long start, unsigned long end)
62 {
63 	struct pdom_dev_data *pdom_dev_data;
64 	struct protection_domain *sva_pdom;
65 	unsigned long flags;
66 
67 	sva_pdom = container_of(mn, struct protection_domain, mn);
68 
69 	spin_lock_irqsave(&sva_pdom->lock, flags);
70 
71 	for_each_pdom_dev_data(pdom_dev_data, sva_pdom) {
72 		amd_iommu_dev_flush_pasid_pages(pdom_dev_data->dev_data,
73 						pdom_dev_data->pasid,
74 						start, end - start);
75 	}
76 
77 	spin_unlock_irqrestore(&sva_pdom->lock, flags);
78 }
79 
80 static void sva_mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
81 {
82 	struct pdom_dev_data *pdom_dev_data, *next;
83 	struct protection_domain *sva_pdom;
84 	unsigned long flags;
85 
86 	sva_pdom = container_of(mn, struct protection_domain, mn);
87 
88 	spin_lock_irqsave(&sva_pdom->lock, flags);
89 
90 	/* Assume dev_data_list contains same PASID with different devices */
91 	for_each_pdom_dev_data_safe(pdom_dev_data, next, sva_pdom)
92 		remove_dev_pasid(pdom_dev_data);
93 
94 	spin_unlock_irqrestore(&sva_pdom->lock, flags);
95 }
96 
97 static const struct mmu_notifier_ops sva_mn = {
98 	.arch_invalidate_secondary_tlbs = sva_arch_invalidate_secondary_tlbs,
99 	.release = sva_mn_release,
100 };
101 
102 int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
103 			    struct device *dev, ioasid_t pasid)
104 {
105 	struct pdom_dev_data *pdom_dev_data;
106 	struct protection_domain *sva_pdom = to_pdomain(domain);
107 	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
108 	unsigned long flags;
109 	int ret = -EINVAL;
110 
111 	/* PASID zero is used for requests from the I/O device without PASID */
112 	if (!is_pasid_valid(dev_data, pasid))
113 		return ret;
114 
115 	/* Make sure PASID is enabled */
116 	if (!is_pasid_enabled(dev_data))
117 		return ret;
118 
119 	/* Add PASID to protection domain pasid list */
120 	pdom_dev_data = kzalloc(sizeof(*pdom_dev_data), GFP_KERNEL);
121 	if (pdom_dev_data == NULL)
122 		return ret;
123 
124 	pdom_dev_data->pasid = pasid;
125 	pdom_dev_data->dev_data = dev_data;
126 
127 	spin_lock_irqsave(&sva_pdom->lock, flags);
128 
129 	/* Setup GCR3 table */
130 	ret = amd_iommu_set_gcr3(dev_data, pasid,
131 				 iommu_virt_to_phys(domain->mm->pgd));
132 	if (ret) {
133 		kfree(pdom_dev_data);
134 		goto out_unlock;
135 	}
136 
137 	list_add(&pdom_dev_data->list, &sva_pdom->dev_data_list);
138 
139 out_unlock:
140 	spin_unlock_irqrestore(&sva_pdom->lock, flags);
141 	return ret;
142 }
143 
144 void amd_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
145 				struct iommu_domain *domain)
146 {
147 	struct protection_domain *sva_pdom;
148 	unsigned long flags;
149 
150 	if (!is_pasid_valid(dev_iommu_priv_get(dev), pasid))
151 		return;
152 
153 	sva_pdom = to_pdomain(domain);
154 
155 	spin_lock_irqsave(&sva_pdom->lock, flags);
156 
157 	/* Remove PASID from dev_data_list */
158 	remove_pdom_dev_pasid(sva_pdom, dev, pasid);
159 
160 	spin_unlock_irqrestore(&sva_pdom->lock, flags);
161 }
162 
163 static void iommu_sva_domain_free(struct iommu_domain *domain)
164 {
165 	struct protection_domain *sva_pdom = to_pdomain(domain);
166 
167 	if (sva_pdom->mn.ops)
168 		mmu_notifier_unregister(&sva_pdom->mn, domain->mm);
169 
170 	amd_iommu_domain_free(domain);
171 }
172 
173 static const struct iommu_domain_ops amd_sva_domain_ops = {
174 	.set_dev_pasid = iommu_sva_set_dev_pasid,
175 	.free	       = iommu_sva_domain_free
176 };
177 
178 struct iommu_domain *amd_iommu_domain_alloc_sva(struct device *dev,
179 						struct mm_struct *mm)
180 {
181 	struct protection_domain *pdom;
182 	int ret;
183 
184 	pdom = protection_domain_alloc(IOMMU_DOMAIN_SVA, dev_to_node(dev));
185 	if (!pdom)
186 		return ERR_PTR(-ENOMEM);
187 
188 	pdom->domain.ops = &amd_sva_domain_ops;
189 	pdom->mn.ops = &sva_mn;
190 
191 	ret = mmu_notifier_register(&pdom->mn, mm);
192 	if (ret) {
193 		protection_domain_free(pdom);
194 		return ERR_PTR(ret);
195 	}
196 
197 	return &pdom->domain;
198 }
199