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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
8128f23c GS |
2 | /* |
3 | * IOMMU API for s390 PCI devices | |
4 | * | |
5 | * Copyright IBM Corp. 2015 | |
6 | * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> | |
7 | */ | |
8 | ||
9 | #include <linux/pci.h> | |
10 | #include <linux/iommu.h> | |
11 | #include <linux/iommu-helper.h> | |
8128f23c GS |
12 | #include <linux/sizes.h> |
13 | #include <asm/pci_dma.h> | |
14 | ||
15 | /* | |
16 | * Physically contiguous memory regions can be mapped with 4 KiB alignment, | |
17 | * we allow all page sizes that are an order of 4KiB (no special large page | |
18 | * support so far). | |
19 | */ | |
20 | #define S390_IOMMU_PGSIZES (~0xFFFUL) | |
21 | ||
cceb8451 | 22 | static const struct iommu_ops s390_iommu_ops; |
f42c2235 | 23 | |
8128f23c GS |
24 | struct s390_domain { |
25 | struct iommu_domain domain; | |
26 | struct list_head devices; | |
27 | unsigned long *dma_table; | |
28 | spinlock_t dma_table_lock; | |
29 | spinlock_t list_lock; | |
30 | }; | |
31 | ||
32 | struct s390_domain_device { | |
33 | struct list_head list; | |
34 | struct zpci_dev *zdev; | |
35 | }; | |
36 | ||
37 | static struct s390_domain *to_s390_domain(struct iommu_domain *dom) | |
38 | { | |
39 | return container_of(dom, struct s390_domain, domain); | |
40 | } | |
41 | ||
42 | static bool s390_iommu_capable(enum iommu_cap cap) | |
43 | { | |
44 | switch (cap) { | |
45 | case IOMMU_CAP_CACHE_COHERENCY: | |
46 | return true; | |
47 | case IOMMU_CAP_INTR_REMAP: | |
48 | return true; | |
49 | default: | |
50 | return false; | |
51 | } | |
52 | } | |
53 | ||
7cd75787 | 54 | static struct iommu_domain *s390_domain_alloc(unsigned domain_type) |
8128f23c GS |
55 | { |
56 | struct s390_domain *s390_domain; | |
57 | ||
58 | if (domain_type != IOMMU_DOMAIN_UNMANAGED) | |
59 | return NULL; | |
60 | ||
61 | s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); | |
62 | if (!s390_domain) | |
63 | return NULL; | |
64 | ||
65 | s390_domain->dma_table = dma_alloc_cpu_table(); | |
66 | if (!s390_domain->dma_table) { | |
67 | kfree(s390_domain); | |
68 | return NULL; | |
69 | } | |
70 | ||
71 | spin_lock_init(&s390_domain->dma_table_lock); | |
72 | spin_lock_init(&s390_domain->list_lock); | |
73 | INIT_LIST_HEAD(&s390_domain->devices); | |
74 | ||
75 | return &s390_domain->domain; | |
76 | } | |
77 | ||
7cd75787 | 78 | static void s390_domain_free(struct iommu_domain *domain) |
8128f23c GS |
79 | { |
80 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
81 | ||
82 | dma_cleanup_tables(s390_domain->dma_table); | |
83 | kfree(s390_domain); | |
84 | } | |
85 | ||
86 | static int s390_iommu_attach_device(struct iommu_domain *domain, | |
87 | struct device *dev) | |
88 | { | |
89 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
90 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
91 | struct s390_domain_device *domain_device; | |
92 | unsigned long flags; | |
93 | int rc; | |
94 | ||
95 | if (!zdev) | |
96 | return -ENODEV; | |
97 | ||
98 | domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL); | |
99 | if (!domain_device) | |
100 | return -ENOMEM; | |
101 | ||
102 | if (zdev->dma_table) | |
103 | zpci_dma_exit_device(zdev); | |
104 | ||
105 | zdev->dma_table = s390_domain->dma_table; | |
bb2b7ffb | 106 | rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, |
8128f23c GS |
107 | (u64) zdev->dma_table); |
108 | if (rc) | |
109 | goto out_restore; | |
110 | ||
111 | spin_lock_irqsave(&s390_domain->list_lock, flags); | |
112 | /* First device defines the DMA range limits */ | |
113 | if (list_empty(&s390_domain->devices)) { | |
114 | domain->geometry.aperture_start = zdev->start_dma; | |
115 | domain->geometry.aperture_end = zdev->end_dma; | |
116 | domain->geometry.force_aperture = true; | |
117 | /* Allow only devices with identical DMA range limits */ | |
118 | } else if (domain->geometry.aperture_start != zdev->start_dma || | |
119 | domain->geometry.aperture_end != zdev->end_dma) { | |
120 | rc = -EINVAL; | |
121 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
122 | goto out_restore; | |
123 | } | |
124 | domain_device->zdev = zdev; | |
125 | zdev->s390_domain = s390_domain; | |
126 | list_add(&domain_device->list, &s390_domain->devices); | |
127 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
128 | ||
129 | return 0; | |
130 | ||
131 | out_restore: | |
132 | zpci_dma_init_device(zdev); | |
133 | kfree(domain_device); | |
134 | ||
135 | return rc; | |
136 | } | |
137 | ||
138 | static void s390_iommu_detach_device(struct iommu_domain *domain, | |
139 | struct device *dev) | |
140 | { | |
141 | struct s390_domain *s390_domain = to_s390_domain(domain); | |
142 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
143 | struct s390_domain_device *domain_device, *tmp; | |
144 | unsigned long flags; | |
145 | int found = 0; | |
146 | ||
147 | if (!zdev) | |
148 | return; | |
149 | ||
150 | spin_lock_irqsave(&s390_domain->list_lock, flags); | |
151 | list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, | |
152 | list) { | |
153 | if (domain_device->zdev == zdev) { | |
154 | list_del(&domain_device->list); | |
155 | kfree(domain_device); | |
156 | found = 1; | |
157 | break; | |
158 | } | |
159 | } | |
160 | spin_unlock_irqrestore(&s390_domain->list_lock, flags); | |
161 | ||
162 | if (found) { | |
163 | zdev->s390_domain = NULL; | |
164 | zpci_unregister_ioat(zdev, 0); | |
165 | zpci_dma_init_device(zdev); | |
166 | } | |
167 | } | |
168 | ||
169 | static int s390_iommu_add_device(struct device *dev) | |
170 | { | |
0929deca | 171 | struct iommu_group *group = iommu_group_get_for_dev(dev); |
f42c2235 | 172 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; |
8128f23c | 173 | |
0929deca JR |
174 | if (IS_ERR(group)) |
175 | return PTR_ERR(group); | |
8128f23c | 176 | |
8128f23c | 177 | iommu_group_put(group); |
f42c2235 | 178 | iommu_device_link(&zdev->iommu_dev, dev); |
8128f23c | 179 | |
0929deca | 180 | return 0; |
8128f23c GS |
181 | } |
182 | ||
183 | static void s390_iommu_remove_device(struct device *dev) | |
184 | { | |
185 | struct zpci_dev *zdev = to_pci_dev(dev)->sysdata; | |
186 | struct iommu_domain *domain; | |
187 | ||
188 | /* | |
189 | * This is a workaround for a scenario where the IOMMU API common code | |
190 | * "forgets" to call the detach_dev callback: After binding a device | |
191 | * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers | |
192 | * the attach_dev), removing the device via | |
193 | * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev, | |
194 | * only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE | |
195 | * notifier. | |
196 | * | |
197 | * So let's call detach_dev from here if it hasn't been called before. | |
198 | */ | |
199 | if (zdev && zdev->s390_domain) { | |
200 | domain = iommu_get_domain_for_dev(dev); | |
201 | if (domain) | |
202 | s390_iommu_detach_device(domain, dev); | |
203 | } | |
204 | ||
f42c2235 | 205 | iommu_device_unlink(&zdev->iommu_dev, dev); |
8128f23c GS |
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 | ||
f42c2235 JR |
336 | int zpci_init_iommu(struct zpci_dev *zdev) |
337 | { | |
338 | int rc = 0; | |
339 | ||
340 | rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL, | |
341 | "s390-iommu.%08x", zdev->fid); | |
342 | if (rc) | |
343 | goto out_err; | |
344 | ||
345 | iommu_device_set_ops(&zdev->iommu_dev, &s390_iommu_ops); | |
346 | ||
347 | rc = iommu_device_register(&zdev->iommu_dev); | |
348 | if (rc) | |
349 | goto out_sysfs; | |
350 | ||
351 | return 0; | |
352 | ||
353 | out_sysfs: | |
354 | iommu_device_sysfs_remove(&zdev->iommu_dev); | |
355 | ||
356 | out_err: | |
357 | return rc; | |
358 | } | |
359 | ||
360 | void zpci_destroy_iommu(struct zpci_dev *zdev) | |
361 | { | |
362 | iommu_device_unregister(&zdev->iommu_dev); | |
363 | iommu_device_sysfs_remove(&zdev->iommu_dev); | |
364 | } | |
365 | ||
cceb8451 | 366 | static const struct iommu_ops s390_iommu_ops = { |
8128f23c GS |
367 | .capable = s390_iommu_capable, |
368 | .domain_alloc = s390_domain_alloc, | |
369 | .domain_free = s390_domain_free, | |
370 | .attach_dev = s390_iommu_attach_device, | |
371 | .detach_dev = s390_iommu_detach_device, | |
372 | .map = s390_iommu_map, | |
373 | .unmap = s390_iommu_unmap, | |
374 | .iova_to_phys = s390_iommu_iova_to_phys, | |
375 | .add_device = s390_iommu_add_device, | |
376 | .remove_device = s390_iommu_remove_device, | |
0929deca | 377 | .device_group = generic_device_group, |
8128f23c GS |
378 | .pgsize_bitmap = S390_IOMMU_PGSIZES, |
379 | }; | |
380 | ||
381 | static int __init s390_iommu_init(void) | |
382 | { | |
383 | return bus_set_iommu(&pci_bus_type, &s390_iommu_ops); | |
384 | } | |
385 | subsys_initcall(s390_iommu_init); |