Commit | Line | Data |
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8128f23c GS |
1 | /* |
2 | * IOMMU API for s390 PCI devices | |
3 | * | |
4 | * Copyright IBM Corp. 2015 | |
5 | * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> | |
6 | */ | |
7 | ||
8 | #include <linux/pci.h> | |
9 | #include <linux/iommu.h> | |
10 | #include <linux/iommu-helper.h> | |
8128f23c GS |
11 | #include <linux/sizes.h> |
12 | #include <asm/pci_dma.h> | |
13 | ||
14 | /* | |
15 | * Physically contiguous memory regions can be mapped with 4 KiB alignment, | |
16 | * we allow all page sizes that are an order of 4KiB (no special large page | |
17 | * support so far). | |
18 | */ | |
19 | #define S390_IOMMU_PGSIZES (~0xFFFUL) | |
20 | ||
21 | struct s390_domain { | |
22 | struct iommu_domain domain; | |
23 | struct list_head devices; | |
24 | unsigned long *dma_table; | |
25 | spinlock_t dma_table_lock; | |
26 | spinlock_t list_lock; | |
27 | }; | |
28 | ||
29 | struct s390_domain_device { | |
30 | struct list_head list; | |
31 | struct zpci_dev *zdev; | |
32 | }; | |
33 | ||
34 | static struct s390_domain *to_s390_domain(struct iommu_domain *dom) | |
35 | { | |
36 | return container_of(dom, struct s390_domain, domain); | |
37 | } | |
38 | ||
39 | static bool s390_iommu_capable(enum iommu_cap cap) | |
40 | { | |
41 | switch (cap) { | |
42 | case IOMMU_CAP_CACHE_COHERENCY: | |
43 | return true; | |
44 | case IOMMU_CAP_INTR_REMAP: | |
45 | return true; | |
46 | default: | |
47 | return false; | |
48 | } | |
49 | } | |
50 | ||
7cd75787 | 51 | static struct iommu_domain *s390_domain_alloc(unsigned domain_type) |
8128f23c GS |
52 | { |
53 | struct s390_domain *s390_domain; | |
54 | ||
55 | if (domain_type != IOMMU_DOMAIN_UNMANAGED) | |
56 | return NULL; | |
57 | ||
58 | s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); | |
59 | if (!s390_domain) | |
60 | return NULL; | |
61 | ||
62 | s390_domain->dma_table = dma_alloc_cpu_table(); | |
63 | if (!s390_domain->dma_table) { | |
64 | kfree(s390_domain); | |
65 | return NULL; | |
66 | } | |
67 | ||
68 | spin_lock_init(&s390_domain->dma_table_lock); | |
69 | spin_lock_init(&s390_domain->list_lock); | |
70 | INIT_LIST_HEAD(&s390_domain->devices); | |
71 | ||
72 | return &s390_domain->domain; | |
73 | } | |
74 | ||
7cd75787 | 75 | static void s390_domain_free(struct iommu_domain *domain) |
8128f23c GS |
76 | { |
77 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
78 | ||
79 | dma_cleanup_tables(s390_domain->dma_table); | |
80 | kfree(s390_domain); | |
81 | } | |
82 | ||
83 | static int s390_iommu_attach_device(struct iommu_domain *domain, | |
84 | struct device *dev) | |
85 | { | |
86 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
87 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
88 | struct s390_domain_device *domain_device; | |
89 | unsigned long flags; | |
90 | int rc; | |
91 | ||
92 | if (!zdev) | |
93 | return -ENODEV; | |
94 | ||
95 | domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL); | |
96 | if (!domain_device) | |
97 | return -ENOMEM; | |
98 | ||
99 | if (zdev->dma_table) | |
100 | zpci_dma_exit_device(zdev); | |
101 | ||
102 | zdev->dma_table = s390_domain->dma_table; | |
bb2b7ffb | 103 | rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, |
8128f23c GS |
104 | (u64) zdev->dma_table); |
105 | if (rc) | |
106 | goto out_restore; | |
107 | ||
108 | spin_lock_irqsave(&s390_domain->list_lock, flags); | |
109 | /* First device defines the DMA range limits */ | |
110 | if (list_empty(&s390_domain->devices)) { | |
111 | domain->geometry.aperture_start = zdev->start_dma; | |
112 | domain->geometry.aperture_end = zdev->end_dma; | |
113 | domain->geometry.force_aperture = true; | |
114 | /* Allow only devices with identical DMA range limits */ | |
115 | } else if (domain->geometry.aperture_start != zdev->start_dma || | |
116 | domain->geometry.aperture_end != zdev->end_dma) { | |
117 | rc = -EINVAL; | |
118 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
119 | goto out_restore; | |
120 | } | |
121 | domain_device->zdev = zdev; | |
122 | zdev->s390_domain = s390_domain; | |
123 | list_add(&domain_device->list, &s390_domain->devices); | |
124 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
125 | ||
126 | return 0; | |
127 | ||
128 | out_restore: | |
129 | zpci_dma_init_device(zdev); | |
130 | kfree(domain_device); | |
131 | ||
132 | return rc; | |
133 | } | |
134 | ||
135 | static void s390_iommu_detach_device(struct iommu_domain *domain, | |
136 | struct device *dev) | |
137 | { | |
138 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
139 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
140 | struct s390_domain_device *domain_device, *tmp; | |
141 | unsigned long flags; | |
142 | int found = 0; | |
143 | ||
144 | if (!zdev) | |
145 | return; | |
146 | ||
147 | spin_lock_irqsave(&s390_domain->list_lock, flags); | |
148 | list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, | |
149 | list) { | |
150 | if (domain_device->zdev == zdev) { | |
151 | list_del(&domain_device->list); | |
152 | kfree(domain_device); | |
153 | found = 1; | |
154 | break; | |
155 | } | |
156 | } | |
157 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
158 | ||
159 | if (found) { | |
160 | zdev->s390_domain = NULL; | |
161 | zpci_unregister_ioat(zdev, 0); | |
162 | zpci_dma_init_device(zdev); | |
163 | } | |
164 | } | |
165 | ||
166 | static int s390_iommu_add_device(struct device *dev) | |
167 | { | |
168 | struct iommu_group *group; | |
169 | int rc; | |
170 | ||
171 | group = iommu_group_get(dev); | |
172 | if (!group) { | |
173 | group = iommu_group_alloc(); | |
174 | if (IS_ERR(group)) | |
175 | return PTR_ERR(group); | |
176 | } | |
177 | ||
178 | rc = iommu_group_add_device(group, dev); | |
179 | iommu_group_put(group); | |
180 | ||
181 | return rc; | |
182 | } | |
183 | ||
184 | static void s390_iommu_remove_device(struct device *dev) | |
185 | { | |
186 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
187 | struct iommu_domain *domain; | |
188 | ||
189 | /* | |
190 | * This is a workaround for a scenario where the IOMMU API common code | |
191 | * "forgets" to call the detach_dev callback: After binding a device | |
192 | * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers | |
193 | * the attach_dev), removing the device via | |
194 | * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev, | |
195 | * only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE | |
196 | * notifier. | |
197 | * | |
198 | * So let's call detach_dev from here if it hasn't been called before. | |
199 | */ | |
200 | if (zdev && zdev->s390_domain) { | |
201 | domain = iommu_get_domain_for_dev(dev); | |
202 | if (domain) | |
203 | s390_iommu_detach_device(domain, dev); | |
204 | } | |
205 | ||
206 | iommu_group_remove_device(dev); | |
207 | } | |
208 | ||
209 | static int s390_iommu_update_trans(struct s390_domain *s390_domain, | |
210 | unsigned long pa, dma_addr_t dma_addr, | |
211 | size_t size, int flags) | |
212 | { | |
213 | struct s390_domain_device *domain_device; | |
214 | u8 *page_addr = (u8 *) (pa & PAGE_MASK); | |
215 | dma_addr_t start_dma_addr = dma_addr; | |
216 | unsigned long irq_flags, nr_pages, i; | |
66728eee | 217 | unsigned long *entry; |
8128f23c GS |
218 | int rc = 0; |
219 | ||
220 | if (dma_addr < s390_domain->domain.geometry.aperture_start || | |
221 | dma_addr + size > s390_domain->domain.geometry.aperture_end) | |
222 | return -EINVAL; | |
223 | ||
224 | nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; | |
225 | if (!nr_pages) | |
226 | return 0; | |
227 | ||
228 | spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags); | |
229 | for (i = 0; i < nr_pages; i++) { | |
66728eee SO |
230 | entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr); |
231 | if (!entry) { | |
232 | rc = -ENOMEM; | |
233 | goto undo_cpu_trans; | |
234 | } | |
235 | dma_update_cpu_trans(entry, page_addr, flags); | |
8128f23c GS |
236 | page_addr += PAGE_SIZE; |
237 | dma_addr += PAGE_SIZE; | |
238 | } | |
239 | ||
240 | spin_lock(&s390_domain->list_lock); | |
241 | list_for_each_entry(domain_device, &s390_domain->devices, list) { | |
242 | rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32, | |
243 | start_dma_addr, nr_pages * PAGE_SIZE); | |
244 | if (rc) | |
245 | break; | |
246 | } | |
247 | spin_unlock(&s390_domain->list_lock); | |
66728eee SO |
248 | |
249 | undo_cpu_trans: | |
250 | if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { | |
251 | flags = ZPCI_PTE_INVALID; | |
252 | while (i-- > 0) { | |
253 | page_addr -= PAGE_SIZE; | |
254 | dma_addr -= PAGE_SIZE; | |
255 | entry = dma_walk_cpu_trans(s390_domain->dma_table, | |
256 | dma_addr); | |
257 | if (!entry) | |
258 | break; | |
259 | dma_update_cpu_trans(entry, page_addr, flags); | |
260 | } | |
261 | } | |
8128f23c GS |
262 | spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags); |
263 | ||
264 | return rc; | |
265 | } | |
266 | ||
267 | static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova, | |
268 | phys_addr_t paddr, size_t size, int prot) | |
269 | { | |
270 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
271 | int flags = ZPCI_PTE_VALID, rc = 0; | |
272 | ||
273 | if (!(prot & IOMMU_READ)) | |
274 | return -EINVAL; | |
275 | ||
276 | if (!(prot & IOMMU_WRITE)) | |
277 | flags |= ZPCI_TABLE_PROTECTED; | |
278 | ||
279 | rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova, | |
280 | size, flags); | |
281 | ||
282 | return rc; | |
283 | } | |
284 | ||
285 | static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain, | |
286 | dma_addr_t iova) | |
287 | { | |
288 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
289 | unsigned long *sto, *pto, *rto, flags; | |
290 | unsigned int rtx, sx, px; | |
291 | phys_addr_t phys = 0; | |
292 | ||
293 | if (iova < domain->geometry.aperture_start || | |
294 | iova > domain->geometry.aperture_end) | |
295 | return 0; | |
296 | ||
297 | rtx = calc_rtx(iova); | |
298 | sx = calc_sx(iova); | |
299 | px = calc_px(iova); | |
300 | rto = s390_domain->dma_table; | |
301 | ||
302 | spin_lock_irqsave(&s390_domain->dma_table_lock, flags); | |
303 | if (rto && reg_entry_isvalid(rto[rtx])) { | |
304 | sto = get_rt_sto(rto[rtx]); | |
305 | if (sto && reg_entry_isvalid(sto[sx])) { | |
306 | pto = get_st_pto(sto[sx]); | |
307 | if (pto && pt_entry_isvalid(pto[px])) | |
308 | phys = pto[px] & ZPCI_PTE_ADDR_MASK; | |
309 | } | |
310 | } | |
311 | spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags); | |
312 | ||
313 | return phys; | |
314 | } | |
315 | ||
316 | static size_t s390_iommu_unmap(struct iommu_domain *domain, | |
317 | unsigned long iova, size_t size) | |
318 | { | |
319 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
320 | int flags = ZPCI_PTE_INVALID; | |
321 | phys_addr_t paddr; | |
322 | int rc; | |
323 | ||
324 | paddr = s390_iommu_iova_to_phys(domain, iova); | |
325 | if (!paddr) | |
326 | return 0; | |
327 | ||
328 | rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova, | |
329 | size, flags); | |
330 | if (rc) | |
331 | return 0; | |
332 | ||
333 | return size; | |
334 | } | |
335 | ||
336 | static struct iommu_ops s390_iommu_ops = { | |
337 | .capable = s390_iommu_capable, | |
338 | .domain_alloc = s390_domain_alloc, | |
339 | .domain_free = s390_domain_free, | |
340 | .attach_dev = s390_iommu_attach_device, | |
341 | .detach_dev = s390_iommu_detach_device, | |
342 | .map = s390_iommu_map, | |
343 | .unmap = s390_iommu_unmap, | |
344 | .iova_to_phys = s390_iommu_iova_to_phys, | |
345 | .add_device = s390_iommu_add_device, | |
346 | .remove_device = s390_iommu_remove_device, | |
347 | .pgsize_bitmap = S390_IOMMU_PGSIZES, | |
348 | }; | |
349 | ||
350 | static int __init s390_iommu_init(void) | |
351 | { | |
352 | return bus_set_iommu(&pci_bus_type, &s390_iommu_ops); | |
353 | } | |
354 | subsys_initcall(s390_iommu_init); |