1 /*
2 * IOMMU for IPMMU/IPMMUI
3 * Copyright (C) 2012 Hideki EIRAKU
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; version 2 of the License.
8 */
9
10 #include <linux/dma-mapping.h>
11 #include <linux/io.h>
12 #include <linux/iommu.h>
13 #include <linux/platform_device.h>
14 #include <linux/sizes.h>
15 #include <linux/slab.h>
16 #include <asm/dma-iommu.h>
17 #include "shmobile-ipmmu.h"
18
19 #define L1_SIZE CONFIG_SHMOBILE_IOMMU_L1SIZE
20 #define L1_LEN (L1_SIZE / 4)
21 #define L1_ALIGN L1_SIZE
22 #define L2_SIZE SZ_1K
23 #define L2_LEN (L2_SIZE / 4)
24 #define L2_ALIGN L2_SIZE
25
26 struct shmobile_iommu_domain_pgtable {
27 uint32_t *pgtable;
28 dma_addr_t handle;
29 };
30
31 struct shmobile_iommu_archdata {
32 struct list_head attached_list;
33 struct dma_iommu_mapping *iommu_mapping;
34 spinlock_t attach_lock;
35 struct shmobile_iommu_domain *attached;
36 int num_attached_devices;
37 struct shmobile_ipmmu *ipmmu;
38 };
39
40 struct shmobile_iommu_domain {
41 struct shmobile_iommu_domain_pgtable l1, l2[L1_LEN];
42 spinlock_t map_lock;
43 spinlock_t attached_list_lock;
44 struct list_head attached_list;
45 struct iommu_domain domain;
46 };
47
48 static struct shmobile_iommu_archdata *ipmmu_archdata;
49 static struct kmem_cache *l1cache, *l2cache;
50
to_sh_domain(struct iommu_domain * dom)51 static struct shmobile_iommu_domain *to_sh_domain(struct iommu_domain *dom)
52 {
53 return container_of(dom, struct shmobile_iommu_domain, domain);
54 }
55
pgtable_alloc(struct shmobile_iommu_domain_pgtable * pgtable,struct kmem_cache * cache,size_t size)56 static int pgtable_alloc(struct shmobile_iommu_domain_pgtable *pgtable,
57 struct kmem_cache *cache, size_t size)
58 {
59 pgtable->pgtable = kmem_cache_zalloc(cache, GFP_ATOMIC);
60 if (!pgtable->pgtable)
61 return -ENOMEM;
62 pgtable->handle = dma_map_single(NULL, pgtable->pgtable, size,
63 DMA_TO_DEVICE);
64 return 0;
65 }
66
pgtable_free(struct shmobile_iommu_domain_pgtable * pgtable,struct kmem_cache * cache,size_t size)67 static void pgtable_free(struct shmobile_iommu_domain_pgtable *pgtable,
68 struct kmem_cache *cache, size_t size)
69 {
70 dma_unmap_single(NULL, pgtable->handle, size, DMA_TO_DEVICE);
71 kmem_cache_free(cache, pgtable->pgtable);
72 }
73
pgtable_read(struct shmobile_iommu_domain_pgtable * pgtable,unsigned int index)74 static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable,
75 unsigned int index)
76 {
77 return pgtable->pgtable[index];
78 }
79
pgtable_write(struct shmobile_iommu_domain_pgtable * pgtable,unsigned int index,unsigned int count,uint32_t val)80 static void pgtable_write(struct shmobile_iommu_domain_pgtable *pgtable,
81 unsigned int index, unsigned int count, uint32_t val)
82 {
83 unsigned int i;
84
85 for (i = 0; i < count; i++)
86 pgtable->pgtable[index + i] = val;
87 dma_sync_single_for_device(NULL, pgtable->handle + index * sizeof(val),
88 sizeof(val) * count, DMA_TO_DEVICE);
89 }
90
shmobile_iommu_domain_alloc(unsigned type)91 static struct iommu_domain *shmobile_iommu_domain_alloc(unsigned type)
92 {
93 struct shmobile_iommu_domain *sh_domain;
94 int i, ret;
95
96 if (type != IOMMU_DOMAIN_UNMANAGED)
97 return NULL;
98
99 sh_domain = kzalloc(sizeof(*sh_domain), GFP_KERNEL);
100 if (!sh_domain)
101 return NULL;
102 ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE);
103 if (ret < 0) {
104 kfree(sh_domain);
105 return NULL;
106 }
107 for (i = 0; i < L1_LEN; i++)
108 sh_domain->l2[i].pgtable = NULL;
109 spin_lock_init(&sh_domain->map_lock);
110 spin_lock_init(&sh_domain->attached_list_lock);
111 INIT_LIST_HEAD(&sh_domain->attached_list);
112 return &sh_domain->domain;
113 }
114
shmobile_iommu_domain_free(struct iommu_domain * domain)115 static void shmobile_iommu_domain_free(struct iommu_domain *domain)
116 {
117 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
118 int i;
119
120 for (i = 0; i < L1_LEN; i++) {
121 if (sh_domain->l2[i].pgtable)
122 pgtable_free(&sh_domain->l2[i], l2cache, L2_SIZE);
123 }
124 pgtable_free(&sh_domain->l1, l1cache, L1_SIZE);
125 kfree(sh_domain);
126 }
127
shmobile_iommu_attach_device(struct iommu_domain * domain,struct device * dev)128 static int shmobile_iommu_attach_device(struct iommu_domain *domain,
129 struct device *dev)
130 {
131 struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
132 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
133 int ret = -EBUSY;
134
135 if (!archdata)
136 return -ENODEV;
137 spin_lock(&sh_domain->attached_list_lock);
138 spin_lock(&archdata->attach_lock);
139 if (archdata->attached != sh_domain) {
140 if (archdata->attached)
141 goto err;
142 ipmmu_tlb_set(archdata->ipmmu, sh_domain->l1.handle, L1_SIZE,
143 0);
144 ipmmu_tlb_flush(archdata->ipmmu);
145 archdata->attached = sh_domain;
146 archdata->num_attached_devices = 0;
147 list_add(&archdata->attached_list, &sh_domain->attached_list);
148 }
149 archdata->num_attached_devices++;
150 ret = 0;
151 err:
152 spin_unlock(&archdata->attach_lock);
153 spin_unlock(&sh_domain->attached_list_lock);
154 return ret;
155 }
156
shmobile_iommu_detach_device(struct iommu_domain * domain,struct device * dev)157 static void shmobile_iommu_detach_device(struct iommu_domain *domain,
158 struct device *dev)
159 {
160 struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
161 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
162
163 if (!archdata)
164 return;
165 spin_lock(&sh_domain->attached_list_lock);
166 spin_lock(&archdata->attach_lock);
167 archdata->num_attached_devices--;
168 if (!archdata->num_attached_devices) {
169 ipmmu_tlb_set(archdata->ipmmu, 0, 0, 0);
170 ipmmu_tlb_flush(archdata->ipmmu);
171 archdata->attached = NULL;
172 list_del(&archdata->attached_list);
173 }
174 spin_unlock(&archdata->attach_lock);
175 spin_unlock(&sh_domain->attached_list_lock);
176 }
177
domain_tlb_flush(struct shmobile_iommu_domain * sh_domain)178 static void domain_tlb_flush(struct shmobile_iommu_domain *sh_domain)
179 {
180 struct shmobile_iommu_archdata *archdata;
181
182 spin_lock(&sh_domain->attached_list_lock);
183 list_for_each_entry(archdata, &sh_domain->attached_list, attached_list)
184 ipmmu_tlb_flush(archdata->ipmmu);
185 spin_unlock(&sh_domain->attached_list_lock);
186 }
187
l2alloc(struct shmobile_iommu_domain * sh_domain,unsigned int l1index)188 static int l2alloc(struct shmobile_iommu_domain *sh_domain,
189 unsigned int l1index)
190 {
191 int ret;
192
193 if (!sh_domain->l2[l1index].pgtable) {
194 ret = pgtable_alloc(&sh_domain->l2[l1index], l2cache, L2_SIZE);
195 if (ret < 0)
196 return ret;
197 }
198 pgtable_write(&sh_domain->l1, l1index, 1,
199 sh_domain->l2[l1index].handle | 0x1);
200 return 0;
201 }
202
l2realfree(struct shmobile_iommu_domain_pgtable * l2)203 static void l2realfree(struct shmobile_iommu_domain_pgtable *l2)
204 {
205 if (l2->pgtable)
206 pgtable_free(l2, l2cache, L2_SIZE);
207 }
208
l2free(struct shmobile_iommu_domain * sh_domain,unsigned int l1index,struct shmobile_iommu_domain_pgtable * l2)209 static void l2free(struct shmobile_iommu_domain *sh_domain,
210 unsigned int l1index,
211 struct shmobile_iommu_domain_pgtable *l2)
212 {
213 pgtable_write(&sh_domain->l1, l1index, 1, 0);
214 if (sh_domain->l2[l1index].pgtable) {
215 *l2 = sh_domain->l2[l1index];
216 sh_domain->l2[l1index].pgtable = NULL;
217 }
218 }
219
shmobile_iommu_map(struct iommu_domain * domain,unsigned long iova,phys_addr_t paddr,size_t size,int prot)220 static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova,
221 phys_addr_t paddr, size_t size, int prot)
222 {
223 struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
224 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
225 unsigned int l1index, l2index;
226 int ret;
227
228 l1index = iova >> 20;
229 switch (size) {
230 case SZ_4K:
231 l2index = (iova >> 12) & 0xff;
232 spin_lock(&sh_domain->map_lock);
233 ret = l2alloc(sh_domain, l1index);
234 if (!ret)
235 pgtable_write(&sh_domain->l2[l1index], l2index, 1,
236 paddr | 0xff2);
237 spin_unlock(&sh_domain->map_lock);
238 break;
239 case SZ_64K:
240 l2index = (iova >> 12) & 0xf0;
241 spin_lock(&sh_domain->map_lock);
242 ret = l2alloc(sh_domain, l1index);
243 if (!ret)
244 pgtable_write(&sh_domain->l2[l1index], l2index, 0x10,
245 paddr | 0xff1);
246 spin_unlock(&sh_domain->map_lock);
247 break;
248 case SZ_1M:
249 spin_lock(&sh_domain->map_lock);
250 l2free(sh_domain, l1index, &l2);
251 pgtable_write(&sh_domain->l1, l1index, 1, paddr | 0xc02);
252 spin_unlock(&sh_domain->map_lock);
253 ret = 0;
254 break;
255 default:
256 ret = -EINVAL;
257 }
258 if (!ret)
259 domain_tlb_flush(sh_domain);
260 l2realfree(&l2);
261 return ret;
262 }
263
shmobile_iommu_unmap(struct iommu_domain * domain,unsigned long iova,size_t size)264 static size_t shmobile_iommu_unmap(struct iommu_domain *domain,
265 unsigned long iova, size_t size)
266 {
267 struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
268 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
269 unsigned int l1index, l2index;
270 uint32_t l2entry = 0;
271 size_t ret = 0;
272
273 l1index = iova >> 20;
274 if (!(iova & 0xfffff) && size >= SZ_1M) {
275 spin_lock(&sh_domain->map_lock);
276 l2free(sh_domain, l1index, &l2);
277 spin_unlock(&sh_domain->map_lock);
278 ret = SZ_1M;
279 goto done;
280 }
281 l2index = (iova >> 12) & 0xff;
282 spin_lock(&sh_domain->map_lock);
283 if (sh_domain->l2[l1index].pgtable)
284 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
285 switch (l2entry & 3) {
286 case 1:
287 if (l2index & 0xf)
288 break;
289 pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 0);
290 ret = SZ_64K;
291 break;
292 case 2:
293 pgtable_write(&sh_domain->l2[l1index], l2index, 1, 0);
294 ret = SZ_4K;
295 break;
296 }
297 spin_unlock(&sh_domain->map_lock);
298 done:
299 if (ret)
300 domain_tlb_flush(sh_domain);
301 l2realfree(&l2);
302 return ret;
303 }
304
shmobile_iommu_iova_to_phys(struct iommu_domain * domain,dma_addr_t iova)305 static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain,
306 dma_addr_t iova)
307 {
308 struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
309 uint32_t l1entry = 0, l2entry = 0;
310 unsigned int l1index, l2index;
311
312 l1index = iova >> 20;
313 l2index = (iova >> 12) & 0xff;
314 spin_lock(&sh_domain->map_lock);
315 if (sh_domain->l2[l1index].pgtable)
316 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
317 else
318 l1entry = pgtable_read(&sh_domain->l1, l1index);
319 spin_unlock(&sh_domain->map_lock);
320 switch (l2entry & 3) {
321 case 1:
322 return (l2entry & ~0xffff) | (iova & 0xffff);
323 case 2:
324 return (l2entry & ~0xfff) | (iova & 0xfff);
325 default:
326 if ((l1entry & 3) == 2)
327 return (l1entry & ~0xfffff) | (iova & 0xfffff);
328 return 0;
329 }
330 }
331
find_dev_name(struct shmobile_ipmmu * ipmmu,const char * dev_name)332 static int find_dev_name(struct shmobile_ipmmu *ipmmu, const char *dev_name)
333 {
334 unsigned int i, n = ipmmu->num_dev_names;
335
336 for (i = 0; i < n; i++) {
337 if (strcmp(ipmmu->dev_names[i], dev_name) == 0)
338 return 1;
339 }
340 return 0;
341 }
342
shmobile_iommu_add_device(struct device * dev)343 static int shmobile_iommu_add_device(struct device *dev)
344 {
345 struct shmobile_iommu_archdata *archdata = ipmmu_archdata;
346 struct dma_iommu_mapping *mapping;
347
348 if (!find_dev_name(archdata->ipmmu, dev_name(dev)))
349 return 0;
350 mapping = archdata->iommu_mapping;
351 if (!mapping) {
352 mapping = arm_iommu_create_mapping(&platform_bus_type, 0,
353 L1_LEN << 20);
354 if (IS_ERR(mapping))
355 return PTR_ERR(mapping);
356 archdata->iommu_mapping = mapping;
357 }
358 dev->archdata.iommu = archdata;
359 if (arm_iommu_attach_device(dev, mapping))
360 pr_err("arm_iommu_attach_device failed\n");
361 return 0;
362 }
363
364 static const struct iommu_ops shmobile_iommu_ops = {
365 .domain_alloc = shmobile_iommu_domain_alloc,
366 .domain_free = shmobile_iommu_domain_free,
367 .attach_dev = shmobile_iommu_attach_device,
368 .detach_dev = shmobile_iommu_detach_device,
369 .map = shmobile_iommu_map,
370 .unmap = shmobile_iommu_unmap,
371 .map_sg = default_iommu_map_sg,
372 .iova_to_phys = shmobile_iommu_iova_to_phys,
373 .add_device = shmobile_iommu_add_device,
374 .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K,
375 };
376
ipmmu_iommu_init(struct shmobile_ipmmu * ipmmu)377 int ipmmu_iommu_init(struct shmobile_ipmmu *ipmmu)
378 {
379 static struct shmobile_iommu_archdata *archdata;
380
381 l1cache = kmem_cache_create("shmobile-iommu-pgtable1", L1_SIZE,
382 L1_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
383 if (!l1cache)
384 return -ENOMEM;
385 l2cache = kmem_cache_create("shmobile-iommu-pgtable2", L2_SIZE,
386 L2_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
387 if (!l2cache) {
388 kmem_cache_destroy(l1cache);
389 return -ENOMEM;
390 }
391 archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
392 if (!archdata) {
393 kmem_cache_destroy(l1cache);
394 kmem_cache_destroy(l2cache);
395 return -ENOMEM;
396 }
397 spin_lock_init(&archdata->attach_lock);
398 archdata->ipmmu = ipmmu;
399 ipmmu_archdata = archdata;
400 bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops);
401 return 0;
402 }
403