summaryrefslogtreecommitdiffstats
path: root/drivers/iommu/shmobile-iommu.c
blob: 464acda0bbc4bb3718a68c24f7568b4378261bb4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
/*
 * IOMMU for IPMMU/IPMMUI
 * Copyright (C) 2012  Hideki EIRAKU
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 */

#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <asm/dma-iommu.h>
#include "shmobile-ipmmu.h"

#define L1_SIZE CONFIG_SHMOBILE_IOMMU_L1SIZE
#define L1_LEN (L1_SIZE / 4)
#define L1_ALIGN L1_SIZE
#define L2_SIZE SZ_1K
#define L2_LEN (L2_SIZE / 4)
#define L2_ALIGN L2_SIZE

struct shmobile_iommu_domain_pgtable {
	uint32_t *pgtable;
	dma_addr_t handle;
};

struct shmobile_iommu_archdata {
	struct list_head attached_list;
	struct dma_iommu_mapping *iommu_mapping;
	spinlock_t attach_lock;
	struct shmobile_iommu_domain *attached;
	int num_attached_devices;
	struct shmobile_ipmmu *ipmmu;
};

struct shmobile_iommu_domain {
	struct shmobile_iommu_domain_pgtable l1, l2[L1_LEN];
	spinlock_t map_lock;
	spinlock_t attached_list_lock;
	struct list_head attached_list;
};

static struct shmobile_iommu_archdata *ipmmu_archdata;
static struct kmem_cache *l1cache, *l2cache;

static int pgtable_alloc(struct shmobile_iommu_domain_pgtable *pgtable,
			 struct kmem_cache *cache, size_t size)
{
	pgtable->pgtable = kmem_cache_zalloc(cache, GFP_ATOMIC);
	if (!pgtable->pgtable)
		return -ENOMEM;
	pgtable->handle = dma_map_single(NULL, pgtable->pgtable, size,
					 DMA_TO_DEVICE);
	return 0;
}

static void pgtable_free(struct shmobile_iommu_domain_pgtable *pgtable,
			 struct kmem_cache *cache, size_t size)
{
	dma_unmap_single(NULL, pgtable->handle, size, DMA_TO_DEVICE);
	kmem_cache_free(cache, pgtable->pgtable);
}

static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable,
			     unsigned int index)
{
	return pgtable->pgtable[index];
}

static void pgtable_write(struct shmobile_iommu_domain_pgtable *pgtable,
			  unsigned int index, unsigned int count, uint32_t val)
{
	unsigned int i;

	for (i = 0; i < count; i++)
		pgtable->pgtable[index + i] = val;
	dma_sync_single_for_device(NULL, pgtable->handle + index * sizeof(val),
				   sizeof(val) * count, DMA_TO_DEVICE);
}

static int shmobile_iommu_domain_init(struct iommu_domain *domain)
{
	struct shmobile_iommu_domain *sh_domain;
	int i, ret;

	sh_domain = kmalloc(sizeof(*sh_domain), GFP_KERNEL);
	if (!sh_domain)
		return -ENOMEM;
	ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE);
	if (ret < 0) {
		kfree(sh_domain);
		return ret;
	}
	for (i = 0; i < L1_LEN; i++)
		sh_domain->l2[i].pgtable = NULL;
	spin_lock_init(&sh_domain->map_lock);
	spin_lock_init(&sh_domain->attached_list_lock);
	INIT_LIST_HEAD(&sh_domain->attached_list);
	domain->priv = sh_domain;
	return 0;
}

static void shmobile_iommu_domain_destroy(struct iommu_domain *domain)
{
	struct shmobile_iommu_domain *sh_domain = domain->priv;
	int i;

	for (i = 0; i < L1_LEN; i++) {
		if (sh_domain->l2[i].pgtable)
			pgtable_free(&sh_domain->l2[i], l2cache, L2_SIZE);
	}
	pgtable_free(&sh_domain->l1, l1cache, L1_SIZE);
	kfree(sh_domain);
	domain->priv = NULL;
}

static int shmobile_iommu_attach_device(struct iommu_domain *domain,
					struct device *dev)
{
	struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
	struct shmobile_iommu_domain *sh_domain = domain->priv;
	int ret = -EBUSY;

	if (!archdata)
		return -ENODEV;
	spin_lock(&sh_domain->attached_list_lock);
	spin_lock(&archdata->attach_lock);
	if (archdata->attached != sh_domain) {
		if (archdata->attached)
			goto err;
		ipmmu_tlb_set(archdata->ipmmu, sh_domain->l1.handle, L1_SIZE,
			      0);
		ipmmu_tlb_flush(archdata->ipmmu);
		archdata->attached = sh_domain;
		archdata->num_attached_devices = 0;
		list_add(&archdata->attached_list, &sh_domain->attached_list);
	}
	archdata->num_attached_devices++;
	ret = 0;
err:
	spin_unlock(&archdata->attach_lock);
	spin_unlock(&sh_domain->attached_list_lock);
	return ret;
}

static void shmobile_iommu_detach_device(struct iommu_domain *domain,
					 struct device *dev)
{
	struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
	struct shmobile_iommu_domain *sh_domain = domain->priv;

	if (!archdata)
		return;
	spin_lock(&sh_domain->attached_list_lock);
	spin_lock(&archdata->attach_lock);
	archdata->num_attached_devices--;
	if (!archdata->num_attached_devices) {
		ipmmu_tlb_set(archdata->ipmmu, 0, 0, 0);
		ipmmu_tlb_flush(archdata->ipmmu);
		archdata->attached = NULL;
		list_del(&archdata->attached_list);
	}
	spin_unlock(&archdata->attach_lock);
	spin_unlock(&sh_domain->attached_list_lock);
}

static void domain_tlb_flush(struct shmobile_iommu_domain *sh_domain)
{
	struct shmobile_iommu_archdata *archdata;

	spin_lock(&sh_domain->attached_list_lock);
	list_for_each_entry(archdata, &sh_domain->attached_list, attached_list)
		ipmmu_tlb_flush(archdata->ipmmu);
	spin_unlock(&sh_domain->attached_list_lock);
}

static int l2alloc(struct shmobile_iommu_domain *sh_domain,
		   unsigned int l1index)
{
	int ret;

	if (!sh_domain->l2[l1index].pgtable) {
		ret = pgtable_alloc(&sh_domain->l2[l1index], l2cache, L2_SIZE);
		if (ret < 0)
			return ret;
	}
	pgtable_write(&sh_domain->l1, l1index, 1,
		      sh_domain->l2[l1index].handle | 0x1);
	return 0;
}

static void l2realfree(struct shmobile_iommu_domain_pgtable *l2)
{
	if (l2->pgtable)
		pgtable_free(l2, l2cache, L2_SIZE);
}

static void l2free(struct shmobile_iommu_domain *sh_domain,
		   unsigned int l1index,
		   struct shmobile_iommu_domain_pgtable *l2)
{
	pgtable_write(&sh_domain->l1, l1index, 1, 0);
	if (sh_domain->l2[l1index].pgtable) {
		*l2 = sh_domain->l2[l1index];
		sh_domain->l2[l1index].pgtable = NULL;
	}
}

static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova,
			      phys_addr_t paddr, size_t size, int prot)
{
	struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
	struct shmobile_iommu_domain *sh_domain = domain->priv;
	unsigned int l1index, l2index;
	int ret;

	l1index = iova >> 20;
	switch (size) {
	case SZ_4K:
		l2index = (iova >> 12) & 0xff;
		spin_lock(&sh_domain->map_lock);
		ret = l2alloc(sh_domain, l1index);
		if (!ret)
			pgtable_write(&sh_domain->l2[l1index], l2index, 1,
				      paddr | 0xff2);
		spin_unlock(&sh_domain->map_lock);
		break;
	case SZ_64K:
		l2index = (iova >> 12) & 0xf0;
		spin_lock(&sh_domain->map_lock);
		ret = l2alloc(sh_domain, l1index);
		if (!ret)
			pgtable_write(&sh_domain->l2[l1index], l2index, 0x10,
				      paddr | 0xff1);
		spin_unlock(&sh_domain->map_lock);
		break;
	case SZ_1M:
		spin_lock(&sh_domain->map_lock);
		l2free(sh_domain, l1index, &l2);
		pgtable_write(&sh_domain->l1, l1index, 1, paddr | 0xc02);
		spin_unlock(&sh_domain->map_lock);
		ret = 0;
		break;
	default:
		ret = -EINVAL;
	}
	if (!ret)
		domain_tlb_flush(sh_domain);
	l2realfree(&l2);
	return ret;
}

static size_t shmobile_iommu_unmap(struct iommu_domain *domain,
				   unsigned long iova, size_t size)
{
	struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
	struct shmobile_iommu_domain *sh_domain = domain->priv;
	unsigned int l1index, l2index;
	uint32_t l2entry = 0;
	size_t ret = 0;

	l1index = iova >> 20;
	if (!(iova & 0xfffff) && size >= SZ_1M) {
		spin_lock(&sh_domain->map_lock);
		l2free(sh_domain, l1index, &l2);
		spin_unlock(&sh_domain->map_lock);
		ret = SZ_1M;
		goto done;
	}
	l2index = (iova >> 12) & 0xff;
	spin_lock(&sh_domain->map_lock);
	if (sh_domain->l2[l1index].pgtable)
		l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
	switch (l2entry & 3) {
	case 1:
		if (l2index & 0xf)
			break;
		pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 0);
		ret = SZ_64K;
		break;
	case 2:
		pgtable_write(&sh_domain->l2[l1index], l2index, 1, 0);
		ret = SZ_4K;
		break;
	}
	spin_unlock(&sh_domain->map_lock);
done:
	if (ret)
		domain_tlb_flush(sh_domain);
	l2realfree(&l2);
	return ret;
}

static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain,
					       dma_addr_t iova)
{
	struct shmobile_iommu_domain *sh_domain = domain->priv;
	uint32_t l1entry = 0, l2entry = 0;
	unsigned int l1index, l2index;

	l1index = iova >> 20;
	l2index = (iova >> 12) & 0xff;
	spin_lock(&sh_domain->map_lock);
	if (sh_domain->l2[l1index].pgtable)
		l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
	else
		l1entry = pgtable_read(&sh_domain->l1, l1index);
	spin_unlock(&sh_domain->map_lock);
	switch (l2entry & 3) {
	case 1:
		return (l2entry & ~0xffff) | (iova & 0xffff);
	case 2:
		return (l2entry & ~0xfff) | (iova & 0xfff);
	default:
		if ((l1entry & 3) == 2)
			return (l1entry & ~0xfffff) | (iova & 0xfffff);
		return 0;
	}
}

static int find_dev_name(struct shmobile_ipmmu *ipmmu, const char *dev_name)
{
	unsigned int i, n = ipmmu->num_dev_names;

	for (i = 0; i < n; i++) {
		if (strcmp(ipmmu->dev_names[i], dev_name) == 0)
			return 1;
	}
	return 0;
}

static int shmobile_iommu_add_device(struct device *dev)
{
	struct shmobile_iommu_archdata *archdata = ipmmu_archdata;
	struct dma_iommu_mapping *mapping;

	if (!find_dev_name(archdata->ipmmu, dev_name(dev)))
		return 0;
	mapping = archdata->iommu_mapping;
	if (!mapping) {
		mapping = arm_iommu_create_mapping(&platform_bus_type, 0,
						   L1_LEN << 20);
		if (IS_ERR(mapping))
			return PTR_ERR(mapping);
		archdata->iommu_mapping = mapping;
	}
	dev->archdata.iommu = archdata;
	if (arm_iommu_attach_device(dev, mapping))
		pr_err("arm_iommu_attach_device failed\n");
	return 0;
}

static struct iommu_ops shmobile_iommu_ops = {
	.domain_init = shmobile_iommu_domain_init,
	.domain_destroy = shmobile_iommu_domain_destroy,
	.attach_dev = shmobile_iommu_attach_device,
	.detach_dev = shmobile_iommu_detach_device,
	.map = shmobile_iommu_map,
	.unmap = shmobile_iommu_unmap,
	.iova_to_phys = shmobile_iommu_iova_to_phys,
	.add_device = shmobile_iommu_add_device,
	.pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K,
};

int ipmmu_iommu_init(struct shmobile_ipmmu *ipmmu)
{
	static struct shmobile_iommu_archdata *archdata;

	l1cache = kmem_cache_create("shmobile-iommu-pgtable1", L1_SIZE,
				    L1_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
	if (!l1cache)
		return -ENOMEM;
	l2cache = kmem_cache_create("shmobile-iommu-pgtable2", L2_SIZE,
				    L2_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
	if (!l2cache) {
		kmem_cache_destroy(l1cache);
		return -ENOMEM;
	}
	archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
	if (!archdata) {
		kmem_cache_destroy(l1cache);
		kmem_cache_destroy(l2cache);
		return -ENOMEM;
	}
	spin_lock_init(&archdata->attach_lock);
	archdata->ipmmu = ipmmu;
	ipmmu_archdata = archdata;
	bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops);
	return 0;
}