xref: /openbmc/linux/drivers/iommu/ipmmu-vmsa.c (revision 06ba8020)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IOMMU API for Renesas VMSA-compatible IPMMU
4  * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
5  *
6  * Copyright (C) 2014-2020 Renesas Electronics Corporation
7  */
8 
9 #include <linux/bitmap.h>
10 #include <linux/delay.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/export.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/io-pgtable.h>
18 #include <linux/iommu.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/sizes.h>
24 #include <linux/slab.h>
25 #include <linux/sys_soc.h>
26 
27 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
28 #include <asm/dma-iommu.h>
29 #else
30 #define arm_iommu_create_mapping(...)	NULL
31 #define arm_iommu_attach_device(...)	-ENODEV
32 #define arm_iommu_release_mapping(...)	do {} while (0)
33 #endif
34 
35 #define IPMMU_CTX_MAX		16U
36 #define IPMMU_CTX_INVALID	-1
37 
38 #define IPMMU_UTLB_MAX		64U
39 
40 struct ipmmu_features {
41 	bool use_ns_alias_offset;
42 	bool has_cache_leaf_nodes;
43 	unsigned int number_of_contexts;
44 	unsigned int num_utlbs;
45 	bool setup_imbuscr;
46 	bool twobit_imttbcr_sl0;
47 	bool reserved_context;
48 	bool cache_snoop;
49 	unsigned int ctx_offset_base;
50 	unsigned int ctx_offset_stride;
51 	unsigned int utlb_offset_base;
52 };
53 
54 struct ipmmu_vmsa_device {
55 	struct device *dev;
56 	void __iomem *base;
57 	struct iommu_device iommu;
58 	struct ipmmu_vmsa_device *root;
59 	const struct ipmmu_features *features;
60 	unsigned int num_ctx;
61 	spinlock_t lock;			/* Protects ctx and domains[] */
62 	DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
63 	struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
64 	s8 utlb_ctx[IPMMU_UTLB_MAX];
65 
66 	struct iommu_group *group;
67 	struct dma_iommu_mapping *mapping;
68 };
69 
70 struct ipmmu_vmsa_domain {
71 	struct ipmmu_vmsa_device *mmu;
72 	struct iommu_domain io_domain;
73 
74 	struct io_pgtable_cfg cfg;
75 	struct io_pgtable_ops *iop;
76 
77 	unsigned int context_id;
78 	struct mutex mutex;			/* Protects mappings */
79 };
80 
81 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
82 {
83 	return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
84 }
85 
86 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
87 {
88 	return dev_iommu_priv_get(dev);
89 }
90 
91 #define TLB_LOOP_TIMEOUT		100	/* 100us */
92 
93 /* -----------------------------------------------------------------------------
94  * Registers Definition
95  */
96 
97 #define IM_NS_ALIAS_OFFSET		0x800
98 
99 /* MMU "context" registers */
100 #define IMCTR				0x0000		/* R-Car Gen2/3 */
101 #define IMCTR_INTEN			(1 << 2)	/* R-Car Gen2/3 */
102 #define IMCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
103 #define IMCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
104 
105 #define IMTTBCR				0x0008		/* R-Car Gen2/3 */
106 #define IMTTBCR_EAE			(1 << 31)	/* R-Car Gen2/3 */
107 #define IMTTBCR_SH0_INNER_SHAREABLE	(3 << 12)	/* R-Car Gen2 only */
108 #define IMTTBCR_ORGN0_WB_WA		(1 << 10)	/* R-Car Gen2 only */
109 #define IMTTBCR_IRGN0_WB_WA		(1 << 8)	/* R-Car Gen2 only */
110 #define IMTTBCR_SL0_TWOBIT_LVL_1	(2 << 6)	/* R-Car Gen3 only */
111 #define IMTTBCR_SL0_LVL_1		(1 << 4)	/* R-Car Gen2 only */
112 
113 #define IMBUSCR				0x000c		/* R-Car Gen2 only */
114 #define IMBUSCR_DVM			(1 << 2)	/* R-Car Gen2 only */
115 #define IMBUSCR_BUSSEL_MASK		(3 << 0)	/* R-Car Gen2 only */
116 
117 #define IMTTLBR0			0x0010		/* R-Car Gen2/3 */
118 #define IMTTUBR0			0x0014		/* R-Car Gen2/3 */
119 
120 #define IMSTR				0x0020		/* R-Car Gen2/3 */
121 #define IMSTR_MHIT			(1 << 4)	/* R-Car Gen2/3 */
122 #define IMSTR_ABORT			(1 << 2)	/* R-Car Gen2/3 */
123 #define IMSTR_PF			(1 << 1)	/* R-Car Gen2/3 */
124 #define IMSTR_TF			(1 << 0)	/* R-Car Gen2/3 */
125 
126 #define IMMAIR0				0x0028		/* R-Car Gen2/3 */
127 
128 #define IMELAR				0x0030		/* R-Car Gen2/3, IMEAR on R-Car Gen2 */
129 #define IMEUAR				0x0034		/* R-Car Gen3 only */
130 
131 /* uTLB registers */
132 #define IMUCTR(n)			((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
133 #define IMUCTR0(n)			(0x0300 + ((n) * 16))		/* R-Car Gen2/3 */
134 #define IMUCTR32(n)			(0x0600 + (((n) - 32) * 16))	/* R-Car Gen3 only */
135 #define IMUCTR_TTSEL_MMU(n)		((n) << 4)	/* R-Car Gen2/3 */
136 #define IMUCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
137 #define IMUCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
138 
139 #define IMUASID(n)			((n) < 32 ? IMUASID0(n) : IMUASID32(n))
140 #define IMUASID0(n)			(0x0308 + ((n) * 16))		/* R-Car Gen2/3 */
141 #define IMUASID32(n)			(0x0608 + (((n) - 32) * 16))	/* R-Car Gen3 only */
142 
143 /* -----------------------------------------------------------------------------
144  * Root device handling
145  */
146 
147 static struct platform_driver ipmmu_driver;
148 
149 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
150 {
151 	return mmu->root == mmu;
152 }
153 
154 static int __ipmmu_check_device(struct device *dev, void *data)
155 {
156 	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
157 	struct ipmmu_vmsa_device **rootp = data;
158 
159 	if (ipmmu_is_root(mmu))
160 		*rootp = mmu;
161 
162 	return 0;
163 }
164 
165 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
166 {
167 	struct ipmmu_vmsa_device *root = NULL;
168 
169 	return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
170 				      __ipmmu_check_device) == 0 ? root : NULL;
171 }
172 
173 /* -----------------------------------------------------------------------------
174  * Read/Write Access
175  */
176 
177 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
178 {
179 	return ioread32(mmu->base + offset);
180 }
181 
182 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
183 			u32 data)
184 {
185 	iowrite32(data, mmu->base + offset);
186 }
187 
188 static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
189 				  unsigned int context_id, unsigned int reg)
190 {
191 	unsigned int base = mmu->features->ctx_offset_base;
192 
193 	if (context_id > 7)
194 		base += 0x800 - 8 * 0x40;
195 
196 	return base + context_id * mmu->features->ctx_offset_stride + reg;
197 }
198 
199 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
200 			  unsigned int context_id, unsigned int reg)
201 {
202 	return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
203 }
204 
205 static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
206 			    unsigned int context_id, unsigned int reg, u32 data)
207 {
208 	ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
209 }
210 
211 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
212 			       unsigned int reg)
213 {
214 	return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
215 }
216 
217 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
218 				 unsigned int reg, u32 data)
219 {
220 	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
221 }
222 
223 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
224 				unsigned int reg, u32 data)
225 {
226 	if (domain->mmu != domain->mmu->root)
227 		ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
228 
229 	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
230 }
231 
232 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
233 {
234 	return mmu->features->utlb_offset_base + reg;
235 }
236 
237 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
238 				unsigned int utlb, u32 data)
239 {
240 	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
241 }
242 
243 static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
244 			       unsigned int utlb, u32 data)
245 {
246 	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
247 }
248 
249 /* -----------------------------------------------------------------------------
250  * TLB and microTLB Management
251  */
252 
253 /* Wait for any pending TLB invalidations to complete */
254 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
255 {
256 	unsigned int count = 0;
257 
258 	while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
259 		cpu_relax();
260 		if (++count == TLB_LOOP_TIMEOUT) {
261 			dev_err_ratelimited(domain->mmu->dev,
262 			"TLB sync timed out -- MMU may be deadlocked\n");
263 			return;
264 		}
265 		udelay(1);
266 	}
267 }
268 
269 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
270 {
271 	u32 reg;
272 
273 	reg = ipmmu_ctx_read_root(domain, IMCTR);
274 	reg |= IMCTR_FLUSH;
275 	ipmmu_ctx_write_all(domain, IMCTR, reg);
276 
277 	ipmmu_tlb_sync(domain);
278 }
279 
280 /*
281  * Enable MMU translation for the microTLB.
282  */
283 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
284 			      unsigned int utlb)
285 {
286 	struct ipmmu_vmsa_device *mmu = domain->mmu;
287 
288 	/*
289 	 * TODO: Reference-count the microTLB as several bus masters can be
290 	 * connected to the same microTLB.
291 	 */
292 
293 	/* TODO: What should we set the ASID to ? */
294 	ipmmu_imuasid_write(mmu, utlb, 0);
295 	/* TODO: Do we need to flush the microTLB ? */
296 	ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
297 				      IMUCTR_FLUSH | IMUCTR_MMUEN);
298 	mmu->utlb_ctx[utlb] = domain->context_id;
299 }
300 
301 static void ipmmu_tlb_flush_all(void *cookie)
302 {
303 	struct ipmmu_vmsa_domain *domain = cookie;
304 
305 	ipmmu_tlb_invalidate(domain);
306 }
307 
308 static void ipmmu_tlb_flush(unsigned long iova, size_t size,
309 				size_t granule, void *cookie)
310 {
311 	ipmmu_tlb_flush_all(cookie);
312 }
313 
314 static const struct iommu_flush_ops ipmmu_flush_ops = {
315 	.tlb_flush_all = ipmmu_tlb_flush_all,
316 	.tlb_flush_walk = ipmmu_tlb_flush,
317 };
318 
319 /* -----------------------------------------------------------------------------
320  * Domain/Context Management
321  */
322 
323 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
324 					 struct ipmmu_vmsa_domain *domain)
325 {
326 	unsigned long flags;
327 	int ret;
328 
329 	spin_lock_irqsave(&mmu->lock, flags);
330 
331 	ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
332 	if (ret != mmu->num_ctx) {
333 		mmu->domains[ret] = domain;
334 		set_bit(ret, mmu->ctx);
335 	} else
336 		ret = -EBUSY;
337 
338 	spin_unlock_irqrestore(&mmu->lock, flags);
339 
340 	return ret;
341 }
342 
343 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
344 				      unsigned int context_id)
345 {
346 	unsigned long flags;
347 
348 	spin_lock_irqsave(&mmu->lock, flags);
349 
350 	clear_bit(context_id, mmu->ctx);
351 	mmu->domains[context_id] = NULL;
352 
353 	spin_unlock_irqrestore(&mmu->lock, flags);
354 }
355 
356 static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
357 {
358 	u64 ttbr;
359 	u32 tmp;
360 
361 	/* TTBR0 */
362 	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
363 	ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
364 	ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
365 
366 	/*
367 	 * TTBCR
368 	 * We use long descriptors and allocate the whole 32-bit VA space to
369 	 * TTBR0.
370 	 */
371 	if (domain->mmu->features->twobit_imttbcr_sl0)
372 		tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
373 	else
374 		tmp = IMTTBCR_SL0_LVL_1;
375 
376 	if (domain->mmu->features->cache_snoop)
377 		tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
378 		       IMTTBCR_IRGN0_WB_WA;
379 
380 	ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
381 
382 	/* MAIR0 */
383 	ipmmu_ctx_write_root(domain, IMMAIR0,
384 			     domain->cfg.arm_lpae_s1_cfg.mair);
385 
386 	/* IMBUSCR */
387 	if (domain->mmu->features->setup_imbuscr)
388 		ipmmu_ctx_write_root(domain, IMBUSCR,
389 				     ipmmu_ctx_read_root(domain, IMBUSCR) &
390 				     ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
391 
392 	/*
393 	 * IMSTR
394 	 * Clear all interrupt flags.
395 	 */
396 	ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
397 
398 	/*
399 	 * IMCTR
400 	 * Enable the MMU and interrupt generation. The long-descriptor
401 	 * translation table format doesn't use TEX remapping. Don't enable AF
402 	 * software management as we have no use for it. Flush the TLB as
403 	 * required when modifying the context registers.
404 	 */
405 	ipmmu_ctx_write_all(domain, IMCTR,
406 			    IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
407 }
408 
409 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
410 {
411 	int ret;
412 
413 	/*
414 	 * Allocate the page table operations.
415 	 *
416 	 * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
417 	 * access, Long-descriptor format" that the NStable bit being set in a
418 	 * table descriptor will result in the NStable and NS bits of all child
419 	 * entries being ignored and considered as being set. The IPMMU seems
420 	 * not to comply with this, as it generates a secure access page fault
421 	 * if any of the NStable and NS bits isn't set when running in
422 	 * non-secure mode.
423 	 */
424 	domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
425 	domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
426 	domain->cfg.ias = 32;
427 	domain->cfg.oas = 40;
428 	domain->cfg.tlb = &ipmmu_flush_ops;
429 	domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
430 	domain->io_domain.geometry.force_aperture = true;
431 	/*
432 	 * TODO: Add support for coherent walk through CCI with DVM and remove
433 	 * cache handling. For now, delegate it to the io-pgtable code.
434 	 */
435 	domain->cfg.coherent_walk = false;
436 	domain->cfg.iommu_dev = domain->mmu->root->dev;
437 
438 	/*
439 	 * Find an unused context.
440 	 */
441 	ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
442 	if (ret < 0)
443 		return ret;
444 
445 	domain->context_id = ret;
446 
447 	domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
448 					   domain);
449 	if (!domain->iop) {
450 		ipmmu_domain_free_context(domain->mmu->root,
451 					  domain->context_id);
452 		return -EINVAL;
453 	}
454 
455 	ipmmu_domain_setup_context(domain);
456 	return 0;
457 }
458 
459 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
460 {
461 	if (!domain->mmu)
462 		return;
463 
464 	/*
465 	 * Disable the context. Flush the TLB as required when modifying the
466 	 * context registers.
467 	 *
468 	 * TODO: Is TLB flush really needed ?
469 	 */
470 	ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
471 	ipmmu_tlb_sync(domain);
472 	ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
473 }
474 
475 /* -----------------------------------------------------------------------------
476  * Fault Handling
477  */
478 
479 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
480 {
481 	const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
482 	struct ipmmu_vmsa_device *mmu = domain->mmu;
483 	unsigned long iova;
484 	u32 status;
485 
486 	status = ipmmu_ctx_read_root(domain, IMSTR);
487 	if (!(status & err_mask))
488 		return IRQ_NONE;
489 
490 	iova = ipmmu_ctx_read_root(domain, IMELAR);
491 	if (IS_ENABLED(CONFIG_64BIT))
492 		iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
493 
494 	/*
495 	 * Clear the error status flags. Unlike traditional interrupt flag
496 	 * registers that must be cleared by writing 1, this status register
497 	 * seems to require 0. The error address register must be read before,
498 	 * otherwise its value will be 0.
499 	 */
500 	ipmmu_ctx_write_root(domain, IMSTR, 0);
501 
502 	/* Log fatal errors. */
503 	if (status & IMSTR_MHIT)
504 		dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
505 				    iova);
506 	if (status & IMSTR_ABORT)
507 		dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
508 				    iova);
509 
510 	if (!(status & (IMSTR_PF | IMSTR_TF)))
511 		return IRQ_NONE;
512 
513 	/*
514 	 * Try to handle page faults and translation faults.
515 	 *
516 	 * TODO: We need to look up the faulty device based on the I/O VA. Use
517 	 * the IOMMU device for now.
518 	 */
519 	if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
520 		return IRQ_HANDLED;
521 
522 	dev_err_ratelimited(mmu->dev,
523 			    "Unhandled fault: status 0x%08x iova 0x%lx\n",
524 			    status, iova);
525 
526 	return IRQ_HANDLED;
527 }
528 
529 static irqreturn_t ipmmu_irq(int irq, void *dev)
530 {
531 	struct ipmmu_vmsa_device *mmu = dev;
532 	irqreturn_t status = IRQ_NONE;
533 	unsigned int i;
534 	unsigned long flags;
535 
536 	spin_lock_irqsave(&mmu->lock, flags);
537 
538 	/*
539 	 * Check interrupts for all active contexts.
540 	 */
541 	for (i = 0; i < mmu->num_ctx; i++) {
542 		if (!mmu->domains[i])
543 			continue;
544 		if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
545 			status = IRQ_HANDLED;
546 	}
547 
548 	spin_unlock_irqrestore(&mmu->lock, flags);
549 
550 	return status;
551 }
552 
553 /* -----------------------------------------------------------------------------
554  * IOMMU Operations
555  */
556 
557 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
558 {
559 	struct ipmmu_vmsa_domain *domain;
560 
561 	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
562 		return NULL;
563 
564 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
565 	if (!domain)
566 		return NULL;
567 
568 	mutex_init(&domain->mutex);
569 
570 	return &domain->io_domain;
571 }
572 
573 static void ipmmu_domain_free(struct iommu_domain *io_domain)
574 {
575 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
576 
577 	/*
578 	 * Free the domain resources. We assume that all devices have already
579 	 * been detached.
580 	 */
581 	ipmmu_domain_destroy_context(domain);
582 	free_io_pgtable_ops(domain->iop);
583 	kfree(domain);
584 }
585 
586 static int ipmmu_attach_device(struct iommu_domain *io_domain,
587 			       struct device *dev)
588 {
589 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
590 	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
591 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
592 	unsigned int i;
593 	int ret = 0;
594 
595 	if (!mmu) {
596 		dev_err(dev, "Cannot attach to IPMMU\n");
597 		return -ENXIO;
598 	}
599 
600 	mutex_lock(&domain->mutex);
601 
602 	if (!domain->mmu) {
603 		/* The domain hasn't been used yet, initialize it. */
604 		domain->mmu = mmu;
605 		ret = ipmmu_domain_init_context(domain);
606 		if (ret < 0) {
607 			dev_err(dev, "Unable to initialize IPMMU context\n");
608 			domain->mmu = NULL;
609 		} else {
610 			dev_info(dev, "Using IPMMU context %u\n",
611 				 domain->context_id);
612 		}
613 	} else if (domain->mmu != mmu) {
614 		/*
615 		 * Something is wrong, we can't attach two devices using
616 		 * different IOMMUs to the same domain.
617 		 */
618 		ret = -EINVAL;
619 	} else
620 		dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
621 
622 	mutex_unlock(&domain->mutex);
623 
624 	if (ret < 0)
625 		return ret;
626 
627 	for (i = 0; i < fwspec->num_ids; ++i)
628 		ipmmu_utlb_enable(domain, fwspec->ids[i]);
629 
630 	return 0;
631 }
632 
633 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
634 		     phys_addr_t paddr, size_t pgsize, size_t pgcount,
635 		     int prot, gfp_t gfp, size_t *mapped)
636 {
637 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
638 
639 	return domain->iop->map_pages(domain->iop, iova, paddr, pgsize, pgcount,
640 				      prot, gfp, mapped);
641 }
642 
643 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
644 			  size_t pgsize, size_t pgcount,
645 			  struct iommu_iotlb_gather *gather)
646 {
647 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
648 
649 	return domain->iop->unmap_pages(domain->iop, iova, pgsize, pgcount, gather);
650 }
651 
652 static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
653 {
654 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
655 
656 	if (domain->mmu)
657 		ipmmu_tlb_flush_all(domain);
658 }
659 
660 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
661 			     struct iommu_iotlb_gather *gather)
662 {
663 	ipmmu_flush_iotlb_all(io_domain);
664 }
665 
666 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
667 				      dma_addr_t iova)
668 {
669 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
670 
671 	/* TODO: Is locking needed ? */
672 
673 	return domain->iop->iova_to_phys(domain->iop, iova);
674 }
675 
676 static int ipmmu_init_platform_device(struct device *dev,
677 				      struct of_phandle_args *args)
678 {
679 	struct platform_device *ipmmu_pdev;
680 
681 	ipmmu_pdev = of_find_device_by_node(args->np);
682 	if (!ipmmu_pdev)
683 		return -ENODEV;
684 
685 	dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
686 
687 	return 0;
688 }
689 
690 static const struct soc_device_attribute soc_needs_opt_in[] = {
691 	{ .family = "R-Car Gen3", },
692 	{ .family = "R-Car Gen4", },
693 	{ .family = "RZ/G2", },
694 	{ /* sentinel */ }
695 };
696 
697 static const struct soc_device_attribute soc_denylist[] = {
698 	{ .soc_id = "r8a774a1", },
699 	{ .soc_id = "r8a7795", .revision = "ES2.*" },
700 	{ .soc_id = "r8a7796", },
701 	{ /* sentinel */ }
702 };
703 
704 static const char * const devices_allowlist[] = {
705 	"ee100000.mmc",
706 	"ee120000.mmc",
707 	"ee140000.mmc",
708 	"ee160000.mmc"
709 };
710 
711 static bool ipmmu_device_is_allowed(struct device *dev)
712 {
713 	unsigned int i;
714 
715 	/*
716 	 * R-Car Gen3/4 and RZ/G2 use the allow list to opt-in devices.
717 	 * For Other SoCs, this returns true anyway.
718 	 */
719 	if (!soc_device_match(soc_needs_opt_in))
720 		return true;
721 
722 	/* Check whether this SoC can use the IPMMU correctly or not */
723 	if (soc_device_match(soc_denylist))
724 		return false;
725 
726 	/* Check whether this device can work with the IPMMU */
727 	for (i = 0; i < ARRAY_SIZE(devices_allowlist); i++) {
728 		if (!strcmp(dev_name(dev), devices_allowlist[i]))
729 			return true;
730 	}
731 
732 	/* Otherwise, do not allow use of IPMMU */
733 	return false;
734 }
735 
736 static int ipmmu_of_xlate(struct device *dev,
737 			  struct of_phandle_args *spec)
738 {
739 	if (!ipmmu_device_is_allowed(dev))
740 		return -ENODEV;
741 
742 	iommu_fwspec_add_ids(dev, spec->args, 1);
743 
744 	/* Initialize once - xlate() will call multiple times */
745 	if (to_ipmmu(dev))
746 		return 0;
747 
748 	return ipmmu_init_platform_device(dev, spec);
749 }
750 
751 static int ipmmu_init_arm_mapping(struct device *dev)
752 {
753 	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
754 	int ret;
755 
756 	/*
757 	 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
758 	 * VAs. This will allocate a corresponding IOMMU domain.
759 	 *
760 	 * TODO:
761 	 * - Create one mapping per context (TLB).
762 	 * - Make the mapping size configurable ? We currently use a 2GB mapping
763 	 *   at a 1GB offset to ensure that NULL VAs will fault.
764 	 */
765 	if (!mmu->mapping) {
766 		struct dma_iommu_mapping *mapping;
767 
768 		mapping = arm_iommu_create_mapping(&platform_bus_type,
769 						   SZ_1G, SZ_2G);
770 		if (IS_ERR(mapping)) {
771 			dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
772 			ret = PTR_ERR(mapping);
773 			goto error;
774 		}
775 
776 		mmu->mapping = mapping;
777 	}
778 
779 	/* Attach the ARM VA mapping to the device. */
780 	ret = arm_iommu_attach_device(dev, mmu->mapping);
781 	if (ret < 0) {
782 		dev_err(dev, "Failed to attach device to VA mapping\n");
783 		goto error;
784 	}
785 
786 	return 0;
787 
788 error:
789 	if (mmu->mapping)
790 		arm_iommu_release_mapping(mmu->mapping);
791 
792 	return ret;
793 }
794 
795 static struct iommu_device *ipmmu_probe_device(struct device *dev)
796 {
797 	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
798 
799 	/*
800 	 * Only let through devices that have been verified in xlate()
801 	 */
802 	if (!mmu)
803 		return ERR_PTR(-ENODEV);
804 
805 	return &mmu->iommu;
806 }
807 
808 static void ipmmu_probe_finalize(struct device *dev)
809 {
810 	int ret = 0;
811 
812 	if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
813 		ret = ipmmu_init_arm_mapping(dev);
814 
815 	if (ret)
816 		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
817 }
818 
819 static void ipmmu_release_device(struct device *dev)
820 {
821 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
822 	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
823 	unsigned int i;
824 
825 	for (i = 0; i < fwspec->num_ids; ++i) {
826 		unsigned int utlb = fwspec->ids[i];
827 
828 		ipmmu_imuctr_write(mmu, utlb, 0);
829 		mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
830 	}
831 
832 	arm_iommu_release_mapping(mmu->mapping);
833 }
834 
835 static struct iommu_group *ipmmu_find_group(struct device *dev)
836 {
837 	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
838 	struct iommu_group *group;
839 
840 	if (mmu->group)
841 		return iommu_group_ref_get(mmu->group);
842 
843 	group = iommu_group_alloc();
844 	if (!IS_ERR(group))
845 		mmu->group = group;
846 
847 	return group;
848 }
849 
850 static const struct iommu_ops ipmmu_ops = {
851 	.domain_alloc = ipmmu_domain_alloc,
852 	.probe_device = ipmmu_probe_device,
853 	.release_device = ipmmu_release_device,
854 	.probe_finalize = ipmmu_probe_finalize,
855 	.device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
856 			? generic_device_group : ipmmu_find_group,
857 	.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
858 	.of_xlate = ipmmu_of_xlate,
859 	.default_domain_ops = &(const struct iommu_domain_ops) {
860 		.attach_dev	= ipmmu_attach_device,
861 		.map_pages	= ipmmu_map,
862 		.unmap_pages	= ipmmu_unmap,
863 		.flush_iotlb_all = ipmmu_flush_iotlb_all,
864 		.iotlb_sync	= ipmmu_iotlb_sync,
865 		.iova_to_phys	= ipmmu_iova_to_phys,
866 		.free		= ipmmu_domain_free,
867 	}
868 };
869 
870 /* -----------------------------------------------------------------------------
871  * Probe/remove and init
872  */
873 
874 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
875 {
876 	unsigned int i;
877 
878 	/* Disable all contexts. */
879 	for (i = 0; i < mmu->num_ctx; ++i)
880 		ipmmu_ctx_write(mmu, i, IMCTR, 0);
881 }
882 
883 static const struct ipmmu_features ipmmu_features_default = {
884 	.use_ns_alias_offset = true,
885 	.has_cache_leaf_nodes = false,
886 	.number_of_contexts = 1, /* software only tested with one context */
887 	.num_utlbs = 32,
888 	.setup_imbuscr = true,
889 	.twobit_imttbcr_sl0 = false,
890 	.reserved_context = false,
891 	.cache_snoop = true,
892 	.ctx_offset_base = 0,
893 	.ctx_offset_stride = 0x40,
894 	.utlb_offset_base = 0,
895 };
896 
897 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
898 	.use_ns_alias_offset = false,
899 	.has_cache_leaf_nodes = true,
900 	.number_of_contexts = 8,
901 	.num_utlbs = 48,
902 	.setup_imbuscr = false,
903 	.twobit_imttbcr_sl0 = true,
904 	.reserved_context = true,
905 	.cache_snoop = false,
906 	.ctx_offset_base = 0,
907 	.ctx_offset_stride = 0x40,
908 	.utlb_offset_base = 0,
909 };
910 
911 static const struct ipmmu_features ipmmu_features_rcar_gen4 = {
912 	.use_ns_alias_offset = false,
913 	.has_cache_leaf_nodes = true,
914 	.number_of_contexts = 16,
915 	.num_utlbs = 64,
916 	.setup_imbuscr = false,
917 	.twobit_imttbcr_sl0 = true,
918 	.reserved_context = true,
919 	.cache_snoop = false,
920 	.ctx_offset_base = 0x10000,
921 	.ctx_offset_stride = 0x1040,
922 	.utlb_offset_base = 0x3000,
923 };
924 
925 static const struct of_device_id ipmmu_of_ids[] = {
926 	{
927 		.compatible = "renesas,ipmmu-vmsa",
928 		.data = &ipmmu_features_default,
929 	}, {
930 		.compatible = "renesas,ipmmu-r8a774a1",
931 		.data = &ipmmu_features_rcar_gen3,
932 	}, {
933 		.compatible = "renesas,ipmmu-r8a774b1",
934 		.data = &ipmmu_features_rcar_gen3,
935 	}, {
936 		.compatible = "renesas,ipmmu-r8a774c0",
937 		.data = &ipmmu_features_rcar_gen3,
938 	}, {
939 		.compatible = "renesas,ipmmu-r8a774e1",
940 		.data = &ipmmu_features_rcar_gen3,
941 	}, {
942 		.compatible = "renesas,ipmmu-r8a7795",
943 		.data = &ipmmu_features_rcar_gen3,
944 	}, {
945 		.compatible = "renesas,ipmmu-r8a7796",
946 		.data = &ipmmu_features_rcar_gen3,
947 	}, {
948 		.compatible = "renesas,ipmmu-r8a77961",
949 		.data = &ipmmu_features_rcar_gen3,
950 	}, {
951 		.compatible = "renesas,ipmmu-r8a77965",
952 		.data = &ipmmu_features_rcar_gen3,
953 	}, {
954 		.compatible = "renesas,ipmmu-r8a77970",
955 		.data = &ipmmu_features_rcar_gen3,
956 	}, {
957 		.compatible = "renesas,ipmmu-r8a77980",
958 		.data = &ipmmu_features_rcar_gen3,
959 	}, {
960 		.compatible = "renesas,ipmmu-r8a77990",
961 		.data = &ipmmu_features_rcar_gen3,
962 	}, {
963 		.compatible = "renesas,ipmmu-r8a77995",
964 		.data = &ipmmu_features_rcar_gen3,
965 	}, {
966 		.compatible = "renesas,ipmmu-r8a779a0",
967 		.data = &ipmmu_features_rcar_gen4,
968 	}, {
969 		.compatible = "renesas,rcar-gen4-ipmmu-vmsa",
970 		.data = &ipmmu_features_rcar_gen4,
971 	}, {
972 		/* Terminator */
973 	},
974 };
975 
976 static int ipmmu_probe(struct platform_device *pdev)
977 {
978 	struct ipmmu_vmsa_device *mmu;
979 	struct resource *res;
980 	int irq;
981 	int ret;
982 
983 	mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
984 	if (!mmu) {
985 		dev_err(&pdev->dev, "cannot allocate device data\n");
986 		return -ENOMEM;
987 	}
988 
989 	mmu->dev = &pdev->dev;
990 	spin_lock_init(&mmu->lock);
991 	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
992 	mmu->features = of_device_get_match_data(&pdev->dev);
993 	memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
994 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
995 	if (ret)
996 		return ret;
997 
998 	/* Map I/O memory and request IRQ. */
999 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1000 	mmu->base = devm_ioremap_resource(&pdev->dev, res);
1001 	if (IS_ERR(mmu->base))
1002 		return PTR_ERR(mmu->base);
1003 
1004 	/*
1005 	 * The IPMMU has two register banks, for secure and non-secure modes.
1006 	 * The bank mapped at the beginning of the IPMMU address space
1007 	 * corresponds to the running mode of the CPU. When running in secure
1008 	 * mode the non-secure register bank is also available at an offset.
1009 	 *
1010 	 * Secure mode operation isn't clearly documented and is thus currently
1011 	 * not implemented in the driver. Furthermore, preliminary tests of
1012 	 * non-secure operation with the main register bank were not successful.
1013 	 * Offset the registers base unconditionally to point to the non-secure
1014 	 * alias space for now.
1015 	 */
1016 	if (mmu->features->use_ns_alias_offset)
1017 		mmu->base += IM_NS_ALIAS_OFFSET;
1018 
1019 	mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1020 
1021 	/*
1022 	 * Determine if this IPMMU instance is a root device by checking for
1023 	 * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1024 	 */
1025 	if (!mmu->features->has_cache_leaf_nodes ||
1026 	    !of_property_present(pdev->dev.of_node, "renesas,ipmmu-main"))
1027 		mmu->root = mmu;
1028 	else
1029 		mmu->root = ipmmu_find_root();
1030 
1031 	/*
1032 	 * Wait until the root device has been registered for sure.
1033 	 */
1034 	if (!mmu->root)
1035 		return -EPROBE_DEFER;
1036 
1037 	/* Root devices have mandatory IRQs */
1038 	if (ipmmu_is_root(mmu)) {
1039 		irq = platform_get_irq(pdev, 0);
1040 		if (irq < 0)
1041 			return irq;
1042 
1043 		ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1044 				       dev_name(&pdev->dev), mmu);
1045 		if (ret < 0) {
1046 			dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1047 			return ret;
1048 		}
1049 
1050 		ipmmu_device_reset(mmu);
1051 
1052 		if (mmu->features->reserved_context) {
1053 			dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1054 			set_bit(0, mmu->ctx);
1055 		}
1056 	}
1057 
1058 	/*
1059 	 * Register the IPMMU to the IOMMU subsystem in the following cases:
1060 	 * - R-Car Gen2 IPMMU (all devices registered)
1061 	 * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1062 	 */
1063 	if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1064 		ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1065 					     dev_name(&pdev->dev));
1066 		if (ret)
1067 			return ret;
1068 
1069 		ret = iommu_device_register(&mmu->iommu, &ipmmu_ops, &pdev->dev);
1070 		if (ret)
1071 			return ret;
1072 	}
1073 
1074 	/*
1075 	 * We can't create the ARM mapping here as it requires the bus to have
1076 	 * an IOMMU, which only happens when bus_set_iommu() is called in
1077 	 * ipmmu_init() after the probe function returns.
1078 	 */
1079 
1080 	platform_set_drvdata(pdev, mmu);
1081 
1082 	return 0;
1083 }
1084 
1085 static void ipmmu_remove(struct platform_device *pdev)
1086 {
1087 	struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1088 
1089 	iommu_device_sysfs_remove(&mmu->iommu);
1090 	iommu_device_unregister(&mmu->iommu);
1091 
1092 	arm_iommu_release_mapping(mmu->mapping);
1093 
1094 	ipmmu_device_reset(mmu);
1095 }
1096 
1097 #ifdef CONFIG_PM_SLEEP
1098 static int ipmmu_resume_noirq(struct device *dev)
1099 {
1100 	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1101 	unsigned int i;
1102 
1103 	/* Reset root MMU and restore contexts */
1104 	if (ipmmu_is_root(mmu)) {
1105 		ipmmu_device_reset(mmu);
1106 
1107 		for (i = 0; i < mmu->num_ctx; i++) {
1108 			if (!mmu->domains[i])
1109 				continue;
1110 
1111 			ipmmu_domain_setup_context(mmu->domains[i]);
1112 		}
1113 	}
1114 
1115 	/* Re-enable active micro-TLBs */
1116 	for (i = 0; i < mmu->features->num_utlbs; i++) {
1117 		if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1118 			continue;
1119 
1120 		ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1121 	}
1122 
1123 	return 0;
1124 }
1125 
1126 static const struct dev_pm_ops ipmmu_pm  = {
1127 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1128 };
1129 #define DEV_PM_OPS	&ipmmu_pm
1130 #else
1131 #define DEV_PM_OPS	NULL
1132 #endif /* CONFIG_PM_SLEEP */
1133 
1134 static struct platform_driver ipmmu_driver = {
1135 	.driver = {
1136 		.name = "ipmmu-vmsa",
1137 		.of_match_table = of_match_ptr(ipmmu_of_ids),
1138 		.pm = DEV_PM_OPS,
1139 	},
1140 	.probe = ipmmu_probe,
1141 	.remove_new = ipmmu_remove,
1142 };
1143 builtin_platform_driver(ipmmu_driver);
1144