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56283174 LB |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /** | |
3 | * intel-pasid.c - PASID idr, table and entry manipulation | |
4 | * | |
5 | * Copyright (C) 2018 Intel Corporation | |
6 | * | |
7 | * Author: Lu Baolu <baolu.lu@linux.intel.com> | |
8 | */ | |
9 | ||
10 | #define pr_fmt(fmt) "DMAR: " fmt | |
11 | ||
12 | #include <linux/dmar.h> | |
13 | #include <linux/intel-iommu.h> | |
14 | #include <linux/iommu.h> | |
15 | #include <linux/memory.h> | |
cc580e41 LB |
16 | #include <linux/pci.h> |
17 | #include <linux/pci-ats.h> | |
56283174 LB |
18 | #include <linux/spinlock.h> |
19 | ||
20 | #include "intel-pasid.h" | |
21 | ||
22 | /* | |
23 | * Intel IOMMU system wide PASID name space: | |
24 | */ | |
25 | static DEFINE_SPINLOCK(pasid_lock); | |
26 | u32 intel_pasid_max_id = PASID_MAX; | |
27 | static DEFINE_IDR(pasid_idr); | |
28 | ||
29 | int intel_pasid_alloc_id(void *ptr, int start, int end, gfp_t gfp) | |
30 | { | |
31 | int ret, min, max; | |
32 | ||
33 | min = max_t(int, start, PASID_MIN); | |
34 | max = min_t(int, end, intel_pasid_max_id); | |
35 | ||
36 | WARN_ON(in_interrupt()); | |
37 | idr_preload(gfp); | |
38 | spin_lock(&pasid_lock); | |
39 | ret = idr_alloc(&pasid_idr, ptr, min, max, GFP_ATOMIC); | |
40 | spin_unlock(&pasid_lock); | |
41 | idr_preload_end(); | |
42 | ||
43 | return ret; | |
44 | } | |
45 | ||
46 | void intel_pasid_free_id(int pasid) | |
47 | { | |
48 | spin_lock(&pasid_lock); | |
49 | idr_remove(&pasid_idr, pasid); | |
50 | spin_unlock(&pasid_lock); | |
51 | } | |
52 | ||
53 | void *intel_pasid_lookup_id(int pasid) | |
54 | { | |
55 | void *p; | |
56 | ||
57 | spin_lock(&pasid_lock); | |
58 | p = idr_find(&pasid_idr, pasid); | |
59 | spin_unlock(&pasid_lock); | |
60 | ||
61 | return p; | |
62 | } | |
cc580e41 LB |
63 | |
64 | /* | |
65 | * Per device pasid table management: | |
66 | */ | |
67 | static inline void | |
68 | device_attach_pasid_table(struct device_domain_info *info, | |
69 | struct pasid_table *pasid_table) | |
70 | { | |
71 | info->pasid_table = pasid_table; | |
72 | list_add(&info->table, &pasid_table->dev); | |
73 | } | |
74 | ||
75 | static inline void | |
76 | device_detach_pasid_table(struct device_domain_info *info, | |
77 | struct pasid_table *pasid_table) | |
78 | { | |
79 | info->pasid_table = NULL; | |
80 | list_del(&info->table); | |
81 | } | |
82 | ||
83 | struct pasid_table_opaque { | |
84 | struct pasid_table **pasid_table; | |
85 | int segment; | |
86 | int bus; | |
87 | int devfn; | |
88 | }; | |
89 | ||
90 | static int search_pasid_table(struct device_domain_info *info, void *opaque) | |
91 | { | |
92 | struct pasid_table_opaque *data = opaque; | |
93 | ||
94 | if (info->iommu->segment == data->segment && | |
95 | info->bus == data->bus && | |
96 | info->devfn == data->devfn && | |
97 | info->pasid_table) { | |
98 | *data->pasid_table = info->pasid_table; | |
99 | return 1; | |
100 | } | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque) | |
106 | { | |
107 | struct pasid_table_opaque *data = opaque; | |
108 | ||
109 | data->segment = pci_domain_nr(pdev->bus); | |
110 | data->bus = PCI_BUS_NUM(alias); | |
111 | data->devfn = alias & 0xff; | |
112 | ||
113 | return for_each_device_domain(&search_pasid_table, data); | |
114 | } | |
115 | ||
116 | /* | |
117 | * Allocate a pasid table for @dev. It should be called in a | |
118 | * single-thread context. | |
119 | */ | |
120 | int intel_pasid_alloc_table(struct device *dev) | |
121 | { | |
122 | struct device_domain_info *info; | |
123 | struct pasid_table *pasid_table; | |
124 | struct pasid_table_opaque data; | |
125 | struct page *pages; | |
126 | size_t size, count; | |
127 | int ret, order; | |
128 | ||
129 | info = dev->archdata.iommu; | |
130 | if (WARN_ON(!info || !dev_is_pci(dev) || | |
131 | !info->pasid_supported || info->pasid_table)) | |
132 | return -EINVAL; | |
133 | ||
134 | /* DMA alias device already has a pasid table, use it: */ | |
135 | data.pasid_table = &pasid_table; | |
136 | ret = pci_for_each_dma_alias(to_pci_dev(dev), | |
137 | &get_alias_pasid_table, &data); | |
138 | if (ret) | |
139 | goto attach_out; | |
140 | ||
141 | pasid_table = kzalloc(sizeof(*pasid_table), GFP_ATOMIC); | |
142 | if (!pasid_table) | |
143 | return -ENOMEM; | |
144 | INIT_LIST_HEAD(&pasid_table->dev); | |
145 | ||
146 | size = sizeof(struct pasid_entry); | |
147 | count = min_t(int, pci_max_pasids(to_pci_dev(dev)), intel_pasid_max_id); | |
148 | order = get_order(size * count); | |
149 | pages = alloc_pages_node(info->iommu->node, | |
150 | GFP_ATOMIC | __GFP_ZERO, | |
151 | order); | |
152 | if (!pages) | |
153 | return -ENOMEM; | |
154 | ||
155 | pasid_table->table = page_address(pages); | |
156 | pasid_table->order = order; | |
157 | pasid_table->max_pasid = count; | |
158 | ||
159 | attach_out: | |
160 | device_attach_pasid_table(info, pasid_table); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | void intel_pasid_free_table(struct device *dev) | |
166 | { | |
167 | struct device_domain_info *info; | |
168 | struct pasid_table *pasid_table; | |
169 | ||
170 | info = dev->archdata.iommu; | |
171 | if (!info || !dev_is_pci(dev) || | |
172 | !info->pasid_supported || !info->pasid_table) | |
173 | return; | |
174 | ||
175 | pasid_table = info->pasid_table; | |
176 | device_detach_pasid_table(info, pasid_table); | |
177 | ||
178 | if (!list_empty(&pasid_table->dev)) | |
179 | return; | |
180 | ||
181 | free_pages((unsigned long)pasid_table->table, pasid_table->order); | |
182 | kfree(pasid_table); | |
183 | } | |
184 | ||
185 | struct pasid_table *intel_pasid_get_table(struct device *dev) | |
186 | { | |
187 | struct device_domain_info *info; | |
188 | ||
189 | info = dev->archdata.iommu; | |
190 | if (!info) | |
191 | return NULL; | |
192 | ||
193 | return info->pasid_table; | |
194 | } | |
195 | ||
196 | int intel_pasid_get_dev_max_id(struct device *dev) | |
197 | { | |
198 | struct device_domain_info *info; | |
199 | ||
200 | info = dev->archdata.iommu; | |
201 | if (!info || !info->pasid_table) | |
202 | return 0; | |
203 | ||
204 | return info->pasid_table->max_pasid; | |
205 | } | |
206 | ||
207 | struct pasid_entry *intel_pasid_get_entry(struct device *dev, int pasid) | |
208 | { | |
209 | struct pasid_table *pasid_table; | |
210 | struct pasid_entry *entries; | |
211 | ||
212 | pasid_table = intel_pasid_get_table(dev); | |
213 | if (WARN_ON(!pasid_table || pasid < 0 || | |
214 | pasid >= intel_pasid_get_dev_max_id(dev))) | |
215 | return NULL; | |
216 | ||
217 | entries = pasid_table->table; | |
218 | ||
219 | return &entries[pasid]; | |
220 | } | |
221 | ||
222 | /* | |
223 | * Interfaces for PASID table entry manipulation: | |
224 | */ | |
225 | static inline void pasid_clear_entry(struct pasid_entry *pe) | |
226 | { | |
227 | WRITE_ONCE(pe->val, 0); | |
228 | } | |
229 | ||
230 | void intel_pasid_clear_entry(struct device *dev, int pasid) | |
231 | { | |
232 | struct pasid_entry *pe; | |
233 | ||
234 | pe = intel_pasid_get_entry(dev, pasid); | |
235 | if (WARN_ON(!pe)) | |
236 | return; | |
237 | ||
238 | pasid_clear_entry(pe); | |
239 | } |