xref: /openbmc/linux/drivers/iommu/tegra-smmu.c (revision 2169e6da)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011-2014 NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/bitops.h>
7 #include <linux/debugfs.h>
8 #include <linux/err.h>
9 #include <linux/iommu.h>
10 #include <linux/kernel.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/dma-mapping.h>
16 
17 #include <soc/tegra/ahb.h>
18 #include <soc/tegra/mc.h>
19 
20 struct tegra_smmu_group {
21 	struct list_head list;
22 	const struct tegra_smmu_group_soc *soc;
23 	struct iommu_group *group;
24 };
25 
26 struct tegra_smmu {
27 	void __iomem *regs;
28 	struct device *dev;
29 
30 	struct tegra_mc *mc;
31 	const struct tegra_smmu_soc *soc;
32 
33 	struct list_head groups;
34 
35 	unsigned long pfn_mask;
36 	unsigned long tlb_mask;
37 
38 	unsigned long *asids;
39 	struct mutex lock;
40 
41 	struct list_head list;
42 
43 	struct dentry *debugfs;
44 
45 	struct iommu_device iommu;	/* IOMMU Core code handle */
46 };
47 
48 struct tegra_smmu_as {
49 	struct iommu_domain domain;
50 	struct tegra_smmu *smmu;
51 	unsigned int use_count;
52 	u32 *count;
53 	struct page **pts;
54 	struct page *pd;
55 	dma_addr_t pd_dma;
56 	unsigned id;
57 	u32 attr;
58 };
59 
60 static struct tegra_smmu_as *to_smmu_as(struct iommu_domain *dom)
61 {
62 	return container_of(dom, struct tegra_smmu_as, domain);
63 }
64 
65 static inline void smmu_writel(struct tegra_smmu *smmu, u32 value,
66 			       unsigned long offset)
67 {
68 	writel(value, smmu->regs + offset);
69 }
70 
71 static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
72 {
73 	return readl(smmu->regs + offset);
74 }
75 
76 #define SMMU_CONFIG 0x010
77 #define  SMMU_CONFIG_ENABLE (1 << 0)
78 
79 #define SMMU_TLB_CONFIG 0x14
80 #define  SMMU_TLB_CONFIG_HIT_UNDER_MISS (1 << 29)
81 #define  SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION (1 << 28)
82 #define  SMMU_TLB_CONFIG_ACTIVE_LINES(smmu) \
83 	((smmu)->soc->num_tlb_lines & (smmu)->tlb_mask)
84 
85 #define SMMU_PTC_CONFIG 0x18
86 #define  SMMU_PTC_CONFIG_ENABLE (1 << 29)
87 #define  SMMU_PTC_CONFIG_REQ_LIMIT(x) (((x) & 0x0f) << 24)
88 #define  SMMU_PTC_CONFIG_INDEX_MAP(x) ((x) & 0x3f)
89 
90 #define SMMU_PTB_ASID 0x01c
91 #define  SMMU_PTB_ASID_VALUE(x) ((x) & 0x7f)
92 
93 #define SMMU_PTB_DATA 0x020
94 #define  SMMU_PTB_DATA_VALUE(dma, attr) ((dma) >> 12 | (attr))
95 
96 #define SMMU_MK_PDE(dma, attr) ((dma) >> SMMU_PTE_SHIFT | (attr))
97 
98 #define SMMU_TLB_FLUSH 0x030
99 #define  SMMU_TLB_FLUSH_VA_MATCH_ALL     (0 << 0)
100 #define  SMMU_TLB_FLUSH_VA_MATCH_SECTION (2 << 0)
101 #define  SMMU_TLB_FLUSH_VA_MATCH_GROUP   (3 << 0)
102 #define  SMMU_TLB_FLUSH_VA_SECTION(addr) ((((addr) & 0xffc00000) >> 12) | \
103 					  SMMU_TLB_FLUSH_VA_MATCH_SECTION)
104 #define  SMMU_TLB_FLUSH_VA_GROUP(addr)   ((((addr) & 0xffffc000) >> 12) | \
105 					  SMMU_TLB_FLUSH_VA_MATCH_GROUP)
106 #define  SMMU_TLB_FLUSH_ASID_MATCH       (1 << 31)
107 
108 #define SMMU_PTC_FLUSH 0x034
109 #define  SMMU_PTC_FLUSH_TYPE_ALL (0 << 0)
110 #define  SMMU_PTC_FLUSH_TYPE_ADR (1 << 0)
111 
112 #define SMMU_PTC_FLUSH_HI 0x9b8
113 #define  SMMU_PTC_FLUSH_HI_MASK 0x3
114 
115 /* per-SWGROUP SMMU_*_ASID register */
116 #define SMMU_ASID_ENABLE (1 << 31)
117 #define SMMU_ASID_MASK 0x7f
118 #define SMMU_ASID_VALUE(x) ((x) & SMMU_ASID_MASK)
119 
120 /* page table definitions */
121 #define SMMU_NUM_PDE 1024
122 #define SMMU_NUM_PTE 1024
123 
124 #define SMMU_SIZE_PD (SMMU_NUM_PDE * 4)
125 #define SMMU_SIZE_PT (SMMU_NUM_PTE * 4)
126 
127 #define SMMU_PDE_SHIFT 22
128 #define SMMU_PTE_SHIFT 12
129 
130 #define SMMU_PD_READABLE	(1 << 31)
131 #define SMMU_PD_WRITABLE	(1 << 30)
132 #define SMMU_PD_NONSECURE	(1 << 29)
133 
134 #define SMMU_PDE_READABLE	(1 << 31)
135 #define SMMU_PDE_WRITABLE	(1 << 30)
136 #define SMMU_PDE_NONSECURE	(1 << 29)
137 #define SMMU_PDE_NEXT		(1 << 28)
138 
139 #define SMMU_PTE_READABLE	(1 << 31)
140 #define SMMU_PTE_WRITABLE	(1 << 30)
141 #define SMMU_PTE_NONSECURE	(1 << 29)
142 
143 #define SMMU_PDE_ATTR		(SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \
144 				 SMMU_PDE_NONSECURE)
145 
146 static unsigned int iova_pd_index(unsigned long iova)
147 {
148 	return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
149 }
150 
151 static unsigned int iova_pt_index(unsigned long iova)
152 {
153 	return (iova >> SMMU_PTE_SHIFT) & (SMMU_NUM_PTE - 1);
154 }
155 
156 static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr)
157 {
158 	addr >>= 12;
159 	return (addr & smmu->pfn_mask) == addr;
160 }
161 
162 static dma_addr_t smmu_pde_to_dma(u32 pde)
163 {
164 	return pde << 12;
165 }
166 
167 static void smmu_flush_ptc_all(struct tegra_smmu *smmu)
168 {
169 	smmu_writel(smmu, SMMU_PTC_FLUSH_TYPE_ALL, SMMU_PTC_FLUSH);
170 }
171 
172 static inline void smmu_flush_ptc(struct tegra_smmu *smmu, dma_addr_t dma,
173 				  unsigned long offset)
174 {
175 	u32 value;
176 
177 	offset &= ~(smmu->mc->soc->atom_size - 1);
178 
179 	if (smmu->mc->soc->num_address_bits > 32) {
180 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
181 		value = (dma >> 32) & SMMU_PTC_FLUSH_HI_MASK;
182 #else
183 		value = 0;
184 #endif
185 		smmu_writel(smmu, value, SMMU_PTC_FLUSH_HI);
186 	}
187 
188 	value = (dma + offset) | SMMU_PTC_FLUSH_TYPE_ADR;
189 	smmu_writel(smmu, value, SMMU_PTC_FLUSH);
190 }
191 
192 static inline void smmu_flush_tlb(struct tegra_smmu *smmu)
193 {
194 	smmu_writel(smmu, SMMU_TLB_FLUSH_VA_MATCH_ALL, SMMU_TLB_FLUSH);
195 }
196 
197 static inline void smmu_flush_tlb_asid(struct tegra_smmu *smmu,
198 				       unsigned long asid)
199 {
200 	u32 value;
201 
202 	if (smmu->soc->num_asids == 4)
203 		value = (asid & 0x3) << 29;
204 	else
205 		value = (asid & 0x7f) << 24;
206 
207 	value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_MATCH_ALL;
208 	smmu_writel(smmu, value, SMMU_TLB_FLUSH);
209 }
210 
211 static inline void smmu_flush_tlb_section(struct tegra_smmu *smmu,
212 					  unsigned long asid,
213 					  unsigned long iova)
214 {
215 	u32 value;
216 
217 	if (smmu->soc->num_asids == 4)
218 		value = (asid & 0x3) << 29;
219 	else
220 		value = (asid & 0x7f) << 24;
221 
222 	value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_SECTION(iova);
223 	smmu_writel(smmu, value, SMMU_TLB_FLUSH);
224 }
225 
226 static inline void smmu_flush_tlb_group(struct tegra_smmu *smmu,
227 					unsigned long asid,
228 					unsigned long iova)
229 {
230 	u32 value;
231 
232 	if (smmu->soc->num_asids == 4)
233 		value = (asid & 0x3) << 29;
234 	else
235 		value = (asid & 0x7f) << 24;
236 
237 	value |= SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_VA_GROUP(iova);
238 	smmu_writel(smmu, value, SMMU_TLB_FLUSH);
239 }
240 
241 static inline void smmu_flush(struct tegra_smmu *smmu)
242 {
243 	smmu_readl(smmu, SMMU_CONFIG);
244 }
245 
246 static int tegra_smmu_alloc_asid(struct tegra_smmu *smmu, unsigned int *idp)
247 {
248 	unsigned long id;
249 
250 	mutex_lock(&smmu->lock);
251 
252 	id = find_first_zero_bit(smmu->asids, smmu->soc->num_asids);
253 	if (id >= smmu->soc->num_asids) {
254 		mutex_unlock(&smmu->lock);
255 		return -ENOSPC;
256 	}
257 
258 	set_bit(id, smmu->asids);
259 	*idp = id;
260 
261 	mutex_unlock(&smmu->lock);
262 	return 0;
263 }
264 
265 static void tegra_smmu_free_asid(struct tegra_smmu *smmu, unsigned int id)
266 {
267 	mutex_lock(&smmu->lock);
268 	clear_bit(id, smmu->asids);
269 	mutex_unlock(&smmu->lock);
270 }
271 
272 static bool tegra_smmu_capable(enum iommu_cap cap)
273 {
274 	return false;
275 }
276 
277 static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
278 {
279 	struct tegra_smmu_as *as;
280 
281 	if (type != IOMMU_DOMAIN_UNMANAGED)
282 		return NULL;
283 
284 	as = kzalloc(sizeof(*as), GFP_KERNEL);
285 	if (!as)
286 		return NULL;
287 
288 	as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
289 
290 	as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
291 	if (!as->pd) {
292 		kfree(as);
293 		return NULL;
294 	}
295 
296 	as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
297 	if (!as->count) {
298 		__free_page(as->pd);
299 		kfree(as);
300 		return NULL;
301 	}
302 
303 	as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
304 	if (!as->pts) {
305 		kfree(as->count);
306 		__free_page(as->pd);
307 		kfree(as);
308 		return NULL;
309 	}
310 
311 	/* setup aperture */
312 	as->domain.geometry.aperture_start = 0;
313 	as->domain.geometry.aperture_end = 0xffffffff;
314 	as->domain.geometry.force_aperture = true;
315 
316 	return &as->domain;
317 }
318 
319 static void tegra_smmu_domain_free(struct iommu_domain *domain)
320 {
321 	struct tegra_smmu_as *as = to_smmu_as(domain);
322 
323 	/* TODO: free page directory and page tables */
324 
325 	WARN_ON_ONCE(as->use_count);
326 	kfree(as->count);
327 	kfree(as->pts);
328 	kfree(as);
329 }
330 
331 static const struct tegra_smmu_swgroup *
332 tegra_smmu_find_swgroup(struct tegra_smmu *smmu, unsigned int swgroup)
333 {
334 	const struct tegra_smmu_swgroup *group = NULL;
335 	unsigned int i;
336 
337 	for (i = 0; i < smmu->soc->num_swgroups; i++) {
338 		if (smmu->soc->swgroups[i].swgroup == swgroup) {
339 			group = &smmu->soc->swgroups[i];
340 			break;
341 		}
342 	}
343 
344 	return group;
345 }
346 
347 static void tegra_smmu_enable(struct tegra_smmu *smmu, unsigned int swgroup,
348 			      unsigned int asid)
349 {
350 	const struct tegra_smmu_swgroup *group;
351 	unsigned int i;
352 	u32 value;
353 
354 	for (i = 0; i < smmu->soc->num_clients; i++) {
355 		const struct tegra_mc_client *client = &smmu->soc->clients[i];
356 
357 		if (client->swgroup != swgroup)
358 			continue;
359 
360 		value = smmu_readl(smmu, client->smmu.reg);
361 		value |= BIT(client->smmu.bit);
362 		smmu_writel(smmu, value, client->smmu.reg);
363 	}
364 
365 	group = tegra_smmu_find_swgroup(smmu, swgroup);
366 	if (group) {
367 		value = smmu_readl(smmu, group->reg);
368 		value &= ~SMMU_ASID_MASK;
369 		value |= SMMU_ASID_VALUE(asid);
370 		value |= SMMU_ASID_ENABLE;
371 		smmu_writel(smmu, value, group->reg);
372 	}
373 }
374 
375 static void tegra_smmu_disable(struct tegra_smmu *smmu, unsigned int swgroup,
376 			       unsigned int asid)
377 {
378 	const struct tegra_smmu_swgroup *group;
379 	unsigned int i;
380 	u32 value;
381 
382 	group = tegra_smmu_find_swgroup(smmu, swgroup);
383 	if (group) {
384 		value = smmu_readl(smmu, group->reg);
385 		value &= ~SMMU_ASID_MASK;
386 		value |= SMMU_ASID_VALUE(asid);
387 		value &= ~SMMU_ASID_ENABLE;
388 		smmu_writel(smmu, value, group->reg);
389 	}
390 
391 	for (i = 0; i < smmu->soc->num_clients; i++) {
392 		const struct tegra_mc_client *client = &smmu->soc->clients[i];
393 
394 		if (client->swgroup != swgroup)
395 			continue;
396 
397 		value = smmu_readl(smmu, client->smmu.reg);
398 		value &= ~BIT(client->smmu.bit);
399 		smmu_writel(smmu, value, client->smmu.reg);
400 	}
401 }
402 
403 static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
404 				 struct tegra_smmu_as *as)
405 {
406 	u32 value;
407 	int err;
408 
409 	if (as->use_count > 0) {
410 		as->use_count++;
411 		return 0;
412 	}
413 
414 	as->pd_dma = dma_map_page(smmu->dev, as->pd, 0, SMMU_SIZE_PD,
415 				  DMA_TO_DEVICE);
416 	if (dma_mapping_error(smmu->dev, as->pd_dma))
417 		return -ENOMEM;
418 
419 	/* We can't handle 64-bit DMA addresses */
420 	if (!smmu_dma_addr_valid(smmu, as->pd_dma)) {
421 		err = -ENOMEM;
422 		goto err_unmap;
423 	}
424 
425 	err = tegra_smmu_alloc_asid(smmu, &as->id);
426 	if (err < 0)
427 		goto err_unmap;
428 
429 	smmu_flush_ptc(smmu, as->pd_dma, 0);
430 	smmu_flush_tlb_asid(smmu, as->id);
431 
432 	smmu_writel(smmu, as->id & 0x7f, SMMU_PTB_ASID);
433 	value = SMMU_PTB_DATA_VALUE(as->pd_dma, as->attr);
434 	smmu_writel(smmu, value, SMMU_PTB_DATA);
435 	smmu_flush(smmu);
436 
437 	as->smmu = smmu;
438 	as->use_count++;
439 
440 	return 0;
441 
442 err_unmap:
443 	dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
444 	return err;
445 }
446 
447 static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
448 				    struct tegra_smmu_as *as)
449 {
450 	if (--as->use_count > 0)
451 		return;
452 
453 	tegra_smmu_free_asid(smmu, as->id);
454 
455 	dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
456 
457 	as->smmu = NULL;
458 }
459 
460 static int tegra_smmu_attach_dev(struct iommu_domain *domain,
461 				 struct device *dev)
462 {
463 	struct tegra_smmu *smmu = dev->archdata.iommu;
464 	struct tegra_smmu_as *as = to_smmu_as(domain);
465 	struct device_node *np = dev->of_node;
466 	struct of_phandle_args args;
467 	unsigned int index = 0;
468 	int err = 0;
469 
470 	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
471 					   &args)) {
472 		unsigned int swgroup = args.args[0];
473 
474 		if (args.np != smmu->dev->of_node) {
475 			of_node_put(args.np);
476 			continue;
477 		}
478 
479 		of_node_put(args.np);
480 
481 		err = tegra_smmu_as_prepare(smmu, as);
482 		if (err < 0)
483 			return err;
484 
485 		tegra_smmu_enable(smmu, swgroup, as->id);
486 		index++;
487 	}
488 
489 	if (index == 0)
490 		return -ENODEV;
491 
492 	return 0;
493 }
494 
495 static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
496 {
497 	struct tegra_smmu_as *as = to_smmu_as(domain);
498 	struct device_node *np = dev->of_node;
499 	struct tegra_smmu *smmu = as->smmu;
500 	struct of_phandle_args args;
501 	unsigned int index = 0;
502 
503 	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
504 					   &args)) {
505 		unsigned int swgroup = args.args[0];
506 
507 		if (args.np != smmu->dev->of_node) {
508 			of_node_put(args.np);
509 			continue;
510 		}
511 
512 		of_node_put(args.np);
513 
514 		tegra_smmu_disable(smmu, swgroup, as->id);
515 		tegra_smmu_as_unprepare(smmu, as);
516 		index++;
517 	}
518 }
519 
520 static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
521 			       u32 value)
522 {
523 	unsigned int pd_index = iova_pd_index(iova);
524 	struct tegra_smmu *smmu = as->smmu;
525 	u32 *pd = page_address(as->pd);
526 	unsigned long offset = pd_index * sizeof(*pd);
527 
528 	/* Set the page directory entry first */
529 	pd[pd_index] = value;
530 
531 	/* The flush the page directory entry from caches */
532 	dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
533 					 sizeof(*pd), DMA_TO_DEVICE);
534 
535 	/* And flush the iommu */
536 	smmu_flush_ptc(smmu, as->pd_dma, offset);
537 	smmu_flush_tlb_section(smmu, as->id, iova);
538 	smmu_flush(smmu);
539 }
540 
541 static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
542 {
543 	u32 *pt = page_address(pt_page);
544 
545 	return pt + iova_pt_index(iova);
546 }
547 
548 static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
549 				  dma_addr_t *dmap)
550 {
551 	unsigned int pd_index = iova_pd_index(iova);
552 	struct page *pt_page;
553 	u32 *pd;
554 
555 	pt_page = as->pts[pd_index];
556 	if (!pt_page)
557 		return NULL;
558 
559 	pd = page_address(as->pd);
560 	*dmap = smmu_pde_to_dma(pd[pd_index]);
561 
562 	return tegra_smmu_pte_offset(pt_page, iova);
563 }
564 
565 static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
566 		       dma_addr_t *dmap)
567 {
568 	unsigned int pde = iova_pd_index(iova);
569 	struct tegra_smmu *smmu = as->smmu;
570 
571 	if (!as->pts[pde]) {
572 		struct page *page;
573 		dma_addr_t dma;
574 
575 		page = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
576 		if (!page)
577 			return NULL;
578 
579 		dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
580 				   DMA_TO_DEVICE);
581 		if (dma_mapping_error(smmu->dev, dma)) {
582 			__free_page(page);
583 			return NULL;
584 		}
585 
586 		if (!smmu_dma_addr_valid(smmu, dma)) {
587 			dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
588 				       DMA_TO_DEVICE);
589 			__free_page(page);
590 			return NULL;
591 		}
592 
593 		as->pts[pde] = page;
594 
595 		tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
596 							      SMMU_PDE_NEXT));
597 
598 		*dmap = dma;
599 	} else {
600 		u32 *pd = page_address(as->pd);
601 
602 		*dmap = smmu_pde_to_dma(pd[pde]);
603 	}
604 
605 	return tegra_smmu_pte_offset(as->pts[pde], iova);
606 }
607 
608 static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
609 {
610 	unsigned int pd_index = iova_pd_index(iova);
611 
612 	as->count[pd_index]++;
613 }
614 
615 static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
616 {
617 	unsigned int pde = iova_pd_index(iova);
618 	struct page *page = as->pts[pde];
619 
620 	/*
621 	 * When no entries in this page table are used anymore, return the
622 	 * memory page to the system.
623 	 */
624 	if (--as->count[pde] == 0) {
625 		struct tegra_smmu *smmu = as->smmu;
626 		u32 *pd = page_address(as->pd);
627 		dma_addr_t pte_dma = smmu_pde_to_dma(pd[pde]);
628 
629 		tegra_smmu_set_pde(as, iova, 0);
630 
631 		dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
632 		__free_page(page);
633 		as->pts[pde] = NULL;
634 	}
635 }
636 
637 static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova,
638 			       u32 *pte, dma_addr_t pte_dma, u32 val)
639 {
640 	struct tegra_smmu *smmu = as->smmu;
641 	unsigned long offset = offset_in_page(pte);
642 
643 	*pte = val;
644 
645 	dma_sync_single_range_for_device(smmu->dev, pte_dma, offset,
646 					 4, DMA_TO_DEVICE);
647 	smmu_flush_ptc(smmu, pte_dma, offset);
648 	smmu_flush_tlb_group(smmu, as->id, iova);
649 	smmu_flush(smmu);
650 }
651 
652 static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
653 			  phys_addr_t paddr, size_t size, int prot)
654 {
655 	struct tegra_smmu_as *as = to_smmu_as(domain);
656 	dma_addr_t pte_dma;
657 	u32 pte_attrs;
658 	u32 *pte;
659 
660 	pte = as_get_pte(as, iova, &pte_dma);
661 	if (!pte)
662 		return -ENOMEM;
663 
664 	/* If we aren't overwriting a pre-existing entry, increment use */
665 	if (*pte == 0)
666 		tegra_smmu_pte_get_use(as, iova);
667 
668 	pte_attrs = SMMU_PTE_NONSECURE;
669 
670 	if (prot & IOMMU_READ)
671 		pte_attrs |= SMMU_PTE_READABLE;
672 
673 	if (prot & IOMMU_WRITE)
674 		pte_attrs |= SMMU_PTE_WRITABLE;
675 
676 	tegra_smmu_set_pte(as, iova, pte, pte_dma,
677 			   __phys_to_pfn(paddr) | pte_attrs);
678 
679 	return 0;
680 }
681 
682 static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
683 			       size_t size)
684 {
685 	struct tegra_smmu_as *as = to_smmu_as(domain);
686 	dma_addr_t pte_dma;
687 	u32 *pte;
688 
689 	pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
690 	if (!pte || !*pte)
691 		return 0;
692 
693 	tegra_smmu_set_pte(as, iova, pte, pte_dma, 0);
694 	tegra_smmu_pte_put_use(as, iova);
695 
696 	return size;
697 }
698 
699 static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
700 					   dma_addr_t iova)
701 {
702 	struct tegra_smmu_as *as = to_smmu_as(domain);
703 	unsigned long pfn;
704 	dma_addr_t pte_dma;
705 	u32 *pte;
706 
707 	pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
708 	if (!pte || !*pte)
709 		return 0;
710 
711 	pfn = *pte & as->smmu->pfn_mask;
712 
713 	return PFN_PHYS(pfn);
714 }
715 
716 static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
717 {
718 	struct platform_device *pdev;
719 	struct tegra_mc *mc;
720 
721 	pdev = of_find_device_by_node(np);
722 	if (!pdev)
723 		return NULL;
724 
725 	mc = platform_get_drvdata(pdev);
726 	if (!mc)
727 		return NULL;
728 
729 	return mc->smmu;
730 }
731 
732 static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
733 				struct of_phandle_args *args)
734 {
735 	const struct iommu_ops *ops = smmu->iommu.ops;
736 	int err;
737 
738 	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
739 	if (err < 0) {
740 		dev_err(dev, "failed to initialize fwspec: %d\n", err);
741 		return err;
742 	}
743 
744 	err = ops->of_xlate(dev, args);
745 	if (err < 0) {
746 		dev_err(dev, "failed to parse SW group ID: %d\n", err);
747 		iommu_fwspec_free(dev);
748 		return err;
749 	}
750 
751 	return 0;
752 }
753 
754 static int tegra_smmu_add_device(struct device *dev)
755 {
756 	struct device_node *np = dev->of_node;
757 	struct tegra_smmu *smmu = NULL;
758 	struct iommu_group *group;
759 	struct of_phandle_args args;
760 	unsigned int index = 0;
761 	int err;
762 
763 	while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
764 					  &args) == 0) {
765 		smmu = tegra_smmu_find(args.np);
766 		if (smmu) {
767 			err = tegra_smmu_configure(smmu, dev, &args);
768 			of_node_put(args.np);
769 
770 			if (err < 0)
771 				return err;
772 
773 			/*
774 			 * Only a single IOMMU master interface is currently
775 			 * supported by the Linux kernel, so abort after the
776 			 * first match.
777 			 */
778 			dev->archdata.iommu = smmu;
779 
780 			iommu_device_link(&smmu->iommu, dev);
781 
782 			break;
783 		}
784 
785 		of_node_put(args.np);
786 		index++;
787 	}
788 
789 	if (!smmu)
790 		return -ENODEV;
791 
792 	group = iommu_group_get_for_dev(dev);
793 	if (IS_ERR(group))
794 		return PTR_ERR(group);
795 
796 	iommu_group_put(group);
797 
798 	return 0;
799 }
800 
801 static void tegra_smmu_remove_device(struct device *dev)
802 {
803 	struct tegra_smmu *smmu = dev->archdata.iommu;
804 
805 	if (smmu)
806 		iommu_device_unlink(&smmu->iommu, dev);
807 
808 	dev->archdata.iommu = NULL;
809 	iommu_group_remove_device(dev);
810 }
811 
812 static const struct tegra_smmu_group_soc *
813 tegra_smmu_find_group(struct tegra_smmu *smmu, unsigned int swgroup)
814 {
815 	unsigned int i, j;
816 
817 	for (i = 0; i < smmu->soc->num_groups; i++)
818 		for (j = 0; j < smmu->soc->groups[i].num_swgroups; j++)
819 			if (smmu->soc->groups[i].swgroups[j] == swgroup)
820 				return &smmu->soc->groups[i];
821 
822 	return NULL;
823 }
824 
825 static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
826 						unsigned int swgroup)
827 {
828 	const struct tegra_smmu_group_soc *soc;
829 	struct tegra_smmu_group *group;
830 
831 	soc = tegra_smmu_find_group(smmu, swgroup);
832 	if (!soc)
833 		return NULL;
834 
835 	mutex_lock(&smmu->lock);
836 
837 	list_for_each_entry(group, &smmu->groups, list)
838 		if (group->soc == soc) {
839 			mutex_unlock(&smmu->lock);
840 			return group->group;
841 		}
842 
843 	group = devm_kzalloc(smmu->dev, sizeof(*group), GFP_KERNEL);
844 	if (!group) {
845 		mutex_unlock(&smmu->lock);
846 		return NULL;
847 	}
848 
849 	INIT_LIST_HEAD(&group->list);
850 	group->soc = soc;
851 
852 	group->group = iommu_group_alloc();
853 	if (IS_ERR(group->group)) {
854 		devm_kfree(smmu->dev, group);
855 		mutex_unlock(&smmu->lock);
856 		return NULL;
857 	}
858 
859 	list_add_tail(&group->list, &smmu->groups);
860 	mutex_unlock(&smmu->lock);
861 
862 	return group->group;
863 }
864 
865 static struct iommu_group *tegra_smmu_device_group(struct device *dev)
866 {
867 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
868 	struct tegra_smmu *smmu = dev->archdata.iommu;
869 	struct iommu_group *group;
870 
871 	group = tegra_smmu_group_get(smmu, fwspec->ids[0]);
872 	if (!group)
873 		group = generic_device_group(dev);
874 
875 	return group;
876 }
877 
878 static int tegra_smmu_of_xlate(struct device *dev,
879 			       struct of_phandle_args *args)
880 {
881 	u32 id = args->args[0];
882 
883 	return iommu_fwspec_add_ids(dev, &id, 1);
884 }
885 
886 static const struct iommu_ops tegra_smmu_ops = {
887 	.capable = tegra_smmu_capable,
888 	.domain_alloc = tegra_smmu_domain_alloc,
889 	.domain_free = tegra_smmu_domain_free,
890 	.attach_dev = tegra_smmu_attach_dev,
891 	.detach_dev = tegra_smmu_detach_dev,
892 	.add_device = tegra_smmu_add_device,
893 	.remove_device = tegra_smmu_remove_device,
894 	.device_group = tegra_smmu_device_group,
895 	.map = tegra_smmu_map,
896 	.unmap = tegra_smmu_unmap,
897 	.iova_to_phys = tegra_smmu_iova_to_phys,
898 	.of_xlate = tegra_smmu_of_xlate,
899 	.pgsize_bitmap = SZ_4K,
900 };
901 
902 static void tegra_smmu_ahb_enable(void)
903 {
904 	static const struct of_device_id ahb_match[] = {
905 		{ .compatible = "nvidia,tegra30-ahb", },
906 		{ }
907 	};
908 	struct device_node *ahb;
909 
910 	ahb = of_find_matching_node(NULL, ahb_match);
911 	if (ahb) {
912 		tegra_ahb_enable_smmu(ahb);
913 		of_node_put(ahb);
914 	}
915 }
916 
917 static int tegra_smmu_swgroups_show(struct seq_file *s, void *data)
918 {
919 	struct tegra_smmu *smmu = s->private;
920 	unsigned int i;
921 	u32 value;
922 
923 	seq_printf(s, "swgroup    enabled  ASID\n");
924 	seq_printf(s, "------------------------\n");
925 
926 	for (i = 0; i < smmu->soc->num_swgroups; i++) {
927 		const struct tegra_smmu_swgroup *group = &smmu->soc->swgroups[i];
928 		const char *status;
929 		unsigned int asid;
930 
931 		value = smmu_readl(smmu, group->reg);
932 
933 		if (value & SMMU_ASID_ENABLE)
934 			status = "yes";
935 		else
936 			status = "no";
937 
938 		asid = value & SMMU_ASID_MASK;
939 
940 		seq_printf(s, "%-9s  %-7s  %#04x\n", group->name, status,
941 			   asid);
942 	}
943 
944 	return 0;
945 }
946 
947 DEFINE_SHOW_ATTRIBUTE(tegra_smmu_swgroups);
948 
949 static int tegra_smmu_clients_show(struct seq_file *s, void *data)
950 {
951 	struct tegra_smmu *smmu = s->private;
952 	unsigned int i;
953 	u32 value;
954 
955 	seq_printf(s, "client       enabled\n");
956 	seq_printf(s, "--------------------\n");
957 
958 	for (i = 0; i < smmu->soc->num_clients; i++) {
959 		const struct tegra_mc_client *client = &smmu->soc->clients[i];
960 		const char *status;
961 
962 		value = smmu_readl(smmu, client->smmu.reg);
963 
964 		if (value & BIT(client->smmu.bit))
965 			status = "yes";
966 		else
967 			status = "no";
968 
969 		seq_printf(s, "%-12s %s\n", client->name, status);
970 	}
971 
972 	return 0;
973 }
974 
975 DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
976 
977 static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
978 {
979 	smmu->debugfs = debugfs_create_dir("smmu", NULL);
980 	if (!smmu->debugfs)
981 		return;
982 
983 	debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,
984 			    &tegra_smmu_swgroups_fops);
985 	debugfs_create_file("clients", S_IRUGO, smmu->debugfs, smmu,
986 			    &tegra_smmu_clients_fops);
987 }
988 
989 static void tegra_smmu_debugfs_exit(struct tegra_smmu *smmu)
990 {
991 	debugfs_remove_recursive(smmu->debugfs);
992 }
993 
994 struct tegra_smmu *tegra_smmu_probe(struct device *dev,
995 				    const struct tegra_smmu_soc *soc,
996 				    struct tegra_mc *mc)
997 {
998 	struct tegra_smmu *smmu;
999 	size_t size;
1000 	u32 value;
1001 	int err;
1002 
1003 	smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
1004 	if (!smmu)
1005 		return ERR_PTR(-ENOMEM);
1006 
1007 	/*
1008 	 * This is a bit of a hack. Ideally we'd want to simply return this
1009 	 * value. However the IOMMU registration process will attempt to add
1010 	 * all devices to the IOMMU when bus_set_iommu() is called. In order
1011 	 * not to rely on global variables to track the IOMMU instance, we
1012 	 * set it here so that it can be looked up from the .add_device()
1013 	 * callback via the IOMMU device's .drvdata field.
1014 	 */
1015 	mc->smmu = smmu;
1016 
1017 	size = BITS_TO_LONGS(soc->num_asids) * sizeof(long);
1018 
1019 	smmu->asids = devm_kzalloc(dev, size, GFP_KERNEL);
1020 	if (!smmu->asids)
1021 		return ERR_PTR(-ENOMEM);
1022 
1023 	INIT_LIST_HEAD(&smmu->groups);
1024 	mutex_init(&smmu->lock);
1025 
1026 	smmu->regs = mc->regs;
1027 	smmu->soc = soc;
1028 	smmu->dev = dev;
1029 	smmu->mc = mc;
1030 
1031 	smmu->pfn_mask = BIT_MASK(mc->soc->num_address_bits - PAGE_SHIFT) - 1;
1032 	dev_dbg(dev, "address bits: %u, PFN mask: %#lx\n",
1033 		mc->soc->num_address_bits, smmu->pfn_mask);
1034 	smmu->tlb_mask = (smmu->soc->num_tlb_lines << 1) - 1;
1035 	dev_dbg(dev, "TLB lines: %u, mask: %#lx\n", smmu->soc->num_tlb_lines,
1036 		smmu->tlb_mask);
1037 
1038 	value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
1039 
1040 	if (soc->supports_request_limit)
1041 		value |= SMMU_PTC_CONFIG_REQ_LIMIT(8);
1042 
1043 	smmu_writel(smmu, value, SMMU_PTC_CONFIG);
1044 
1045 	value = SMMU_TLB_CONFIG_HIT_UNDER_MISS |
1046 		SMMU_TLB_CONFIG_ACTIVE_LINES(smmu);
1047 
1048 	if (soc->supports_round_robin_arbitration)
1049 		value |= SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION;
1050 
1051 	smmu_writel(smmu, value, SMMU_TLB_CONFIG);
1052 
1053 	smmu_flush_ptc_all(smmu);
1054 	smmu_flush_tlb(smmu);
1055 	smmu_writel(smmu, SMMU_CONFIG_ENABLE, SMMU_CONFIG);
1056 	smmu_flush(smmu);
1057 
1058 	tegra_smmu_ahb_enable();
1059 
1060 	err = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, dev_name(dev));
1061 	if (err)
1062 		return ERR_PTR(err);
1063 
1064 	iommu_device_set_ops(&smmu->iommu, &tegra_smmu_ops);
1065 	iommu_device_set_fwnode(&smmu->iommu, dev->fwnode);
1066 
1067 	err = iommu_device_register(&smmu->iommu);
1068 	if (err) {
1069 		iommu_device_sysfs_remove(&smmu->iommu);
1070 		return ERR_PTR(err);
1071 	}
1072 
1073 	err = bus_set_iommu(&platform_bus_type, &tegra_smmu_ops);
1074 	if (err < 0) {
1075 		iommu_device_unregister(&smmu->iommu);
1076 		iommu_device_sysfs_remove(&smmu->iommu);
1077 		return ERR_PTR(err);
1078 	}
1079 
1080 	if (IS_ENABLED(CONFIG_DEBUG_FS))
1081 		tegra_smmu_debugfs_init(smmu);
1082 
1083 	return smmu;
1084 }
1085 
1086 void tegra_smmu_remove(struct tegra_smmu *smmu)
1087 {
1088 	iommu_device_unregister(&smmu->iommu);
1089 	iommu_device_sysfs_remove(&smmu->iommu);
1090 
1091 	if (IS_ENABLED(CONFIG_DEBUG_FS))
1092 		tegra_smmu_debugfs_exit(smmu);
1093 }
1094