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/iopoll.h>
18#include <linux/io-pgtable.h>
19#include <linux/iommu.h>
20#include <linux/of.h>
21#include <linux/of_platform.h>
22#include <linux/pci.h>
23#include <linux/platform_device.h>
24#include <linux/sizes.h>
25#include <linux/slab.h>
26#include <linux/sys_soc.h>
27
28#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
29#include <asm/dma-iommu.h>
30#else
31#define arm_iommu_create_mapping(...)	NULL
32#define arm_iommu_attach_device(...)	-ENODEV
33#define arm_iommu_release_mapping(...)	do {} while (0)
34#endif
35
36#define IPMMU_CTX_MAX		16U
37#define IPMMU_CTX_INVALID	-1
38
39#define IPMMU_UTLB_MAX		64U
40
41struct ipmmu_features {
42	bool use_ns_alias_offset;
43	bool has_cache_leaf_nodes;
44	unsigned int number_of_contexts;
45	unsigned int num_utlbs;
46	bool setup_imbuscr;
47	bool twobit_imttbcr_sl0;
48	bool reserved_context;
49	bool cache_snoop;
50	unsigned int ctx_offset_base;
51	unsigned int ctx_offset_stride;
52	unsigned int utlb_offset_base;
53};
54
55struct ipmmu_vmsa_device {
56	struct device *dev;
57	void __iomem *base;
58	struct iommu_device iommu;
59	struct ipmmu_vmsa_device *root;
60	const struct ipmmu_features *features;
61	unsigned int num_ctx;
62	spinlock_t lock;			/* Protects ctx and domains[] */
63	DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
64	struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
65	s8 utlb_ctx[IPMMU_UTLB_MAX];
66
67	struct iommu_group *group;
68	struct dma_iommu_mapping *mapping;
69};
70
71struct ipmmu_vmsa_domain {
72	struct ipmmu_vmsa_device *mmu;
73	struct iommu_domain io_domain;
74
75	struct io_pgtable_cfg cfg;
76	struct io_pgtable_ops *iop;
77
78	unsigned int context_id;
79	struct mutex mutex;			/* Protects mappings */
80};
81
82static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
83{
84	return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
85}
86
87static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
88{
89	return dev_iommu_priv_get(dev);
90}
91
92#define TLB_LOOP_TIMEOUT		100	/* 100us */
93
94/* -----------------------------------------------------------------------------
95 * Registers Definition
96 */
97
98#define IM_NS_ALIAS_OFFSET		0x800
99
100/* MMU "context" registers */
101#define IMCTR				0x0000		/* R-Car Gen2/3 */
102#define IMCTR_INTEN			(1 << 2)	/* R-Car Gen2/3 */
103#define IMCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
104#define IMCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
105
106#define IMTTBCR				0x0008		/* R-Car Gen2/3 */
107#define IMTTBCR_EAE			(1 << 31)	/* R-Car Gen2/3 */
108#define IMTTBCR_SH0_INNER_SHAREABLE	(3 << 12)	/* R-Car Gen2 only */
109#define IMTTBCR_ORGN0_WB_WA		(1 << 10)	/* R-Car Gen2 only */
110#define IMTTBCR_IRGN0_WB_WA		(1 << 8)	/* R-Car Gen2 only */
111#define IMTTBCR_SL0_TWOBIT_LVL_1	(2 << 6)	/* R-Car Gen3 only */
112#define IMTTBCR_SL0_LVL_1		(1 << 4)	/* R-Car Gen2 only */
113
114#define IMBUSCR				0x000c		/* R-Car Gen2 only */
115#define IMBUSCR_DVM			(1 << 2)	/* R-Car Gen2 only */
116#define IMBUSCR_BUSSEL_MASK		(3 << 0)	/* R-Car Gen2 only */
117
118#define IMTTLBR0			0x0010		/* R-Car Gen2/3 */
119#define IMTTUBR0			0x0014		/* R-Car Gen2/3 */
120
121#define IMSTR				0x0020		/* R-Car Gen2/3 */
122#define IMSTR_MHIT			(1 << 4)	/* R-Car Gen2/3 */
123#define IMSTR_ABORT			(1 << 2)	/* R-Car Gen2/3 */
124#define IMSTR_PF			(1 << 1)	/* R-Car Gen2/3 */
125#define IMSTR_TF			(1 << 0)	/* R-Car Gen2/3 */
126
127#define IMMAIR0				0x0028		/* R-Car Gen2/3 */
128
129#define IMELAR				0x0030		/* R-Car Gen2/3, IMEAR on R-Car Gen2 */
130#define IMEUAR				0x0034		/* R-Car Gen3 only */
131
132/* uTLB registers */
133#define IMUCTR(n)			((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
134#define IMUCTR0(n)			(0x0300 + ((n) * 16))		/* R-Car Gen2/3 */
135#define IMUCTR32(n)			(0x0600 + (((n) - 32) * 16))	/* R-Car Gen3 only */
136#define IMUCTR_TTSEL_MMU(n)		((n) << 4)	/* R-Car Gen2/3 */
137#define IMUCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
138#define IMUCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
139
140#define IMUASID(n)			((n) < 32 ? IMUASID0(n) : IMUASID32(n))
141#define IMUASID0(n)			(0x0308 + ((n) * 16))		/* R-Car Gen2/3 */
142#define IMUASID32(n)			(0x0608 + (((n) - 32) * 16))	/* R-Car Gen3 only */
143
144/* -----------------------------------------------------------------------------
145 * Root device handling
146 */
147
148static struct platform_driver ipmmu_driver;
149
150static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
151{
152	return mmu->root == mmu;
153}
154
155static int __ipmmu_check_device(struct device *dev, void *data)
156{
157	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
158	struct ipmmu_vmsa_device **rootp = data;
159
160	if (ipmmu_is_root(mmu))
161		*rootp = mmu;
162
163	return 0;
164}
165
166static struct ipmmu_vmsa_device *ipmmu_find_root(void)
167{
168	struct ipmmu_vmsa_device *root = NULL;
169
170	return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
171				      __ipmmu_check_device) == 0 ? root : NULL;
172}
173
174/* -----------------------------------------------------------------------------
175 * Read/Write Access
176 */
177
178static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
179{
180	return ioread32(mmu->base + offset);
181}
182
183static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
184			u32 data)
185{
186	iowrite32(data, mmu->base + offset);
187}
188
189static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
190				  unsigned int context_id, unsigned int reg)
191{
192	unsigned int base = mmu->features->ctx_offset_base;
193
194	if (context_id > 7)
195		base += 0x800 - 8 * 0x40;
196
197	return base + context_id * mmu->features->ctx_offset_stride + reg;
198}
199
200static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
201			  unsigned int context_id, unsigned int reg)
202{
203	return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
204}
205
206static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
207			    unsigned int context_id, unsigned int reg, u32 data)
208{
209	ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
210}
211
212static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
213			       unsigned int reg)
214{
215	return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
216}
217
218static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
219				 unsigned int reg, u32 data)
220{
221	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
222}
223
224static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
225				unsigned int reg, u32 data)
226{
227	if (domain->mmu != domain->mmu->root)
228		ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
229
230	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
231}
232
233static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
234{
235	return mmu->features->utlb_offset_base + reg;
236}
237
238static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
239				unsigned int utlb, u32 data)
240{
241	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
242}
243
244static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
245			       unsigned int utlb, u32 data)
246{
247	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
248}
249
250/* -----------------------------------------------------------------------------
251 * TLB and microTLB Management
252 */
253
254/* Wait for any pending TLB invalidations to complete */
255static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
256{
257	u32 val;
258
259	if (read_poll_timeout_atomic(ipmmu_ctx_read_root, val,
260				     !(val & IMCTR_FLUSH), 1, TLB_LOOP_TIMEOUT,
261				     false, domain, IMCTR))
262		dev_err_ratelimited(domain->mmu->dev,
263			"TLB sync timed out -- MMU may be deadlocked\n");
264}
265
266static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
267{
268	u32 reg;
269
270	reg = ipmmu_ctx_read_root(domain, IMCTR);
271	reg |= IMCTR_FLUSH;
272	ipmmu_ctx_write_all(domain, IMCTR, reg);
273
274	ipmmu_tlb_sync(domain);
275}
276
277/*
278 * Enable MMU translation for the microTLB.
279 */
280static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
281			      unsigned int utlb)
282{
283	struct ipmmu_vmsa_device *mmu = domain->mmu;
284
285	/*
286	 * TODO: Reference-count the microTLB as several bus masters can be
287	 * connected to the same microTLB.
288	 */
289
290	/* TODO: What should we set the ASID to ? */
291	ipmmu_imuasid_write(mmu, utlb, 0);
292	/* TODO: Do we need to flush the microTLB ? */
293	ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
294				      IMUCTR_FLUSH | IMUCTR_MMUEN);
295	mmu->utlb_ctx[utlb] = domain->context_id;
296}
297
298static void ipmmu_tlb_flush_all(void *cookie)
299{
300	struct ipmmu_vmsa_domain *domain = cookie;
301
302	ipmmu_tlb_invalidate(domain);
303}
304
305static void ipmmu_tlb_flush(unsigned long iova, size_t size,
306				size_t granule, void *cookie)
307{
308	ipmmu_tlb_flush_all(cookie);
309}
310
311static const struct iommu_flush_ops ipmmu_flush_ops = {
312	.tlb_flush_all = ipmmu_tlb_flush_all,
313	.tlb_flush_walk = ipmmu_tlb_flush,
314};
315
316/* -----------------------------------------------------------------------------
317 * Domain/Context Management
318 */
319
320static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
321					 struct ipmmu_vmsa_domain *domain)
322{
323	unsigned long flags;
324	int ret;
325
326	spin_lock_irqsave(&mmu->lock, flags);
327
328	ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
329	if (ret != mmu->num_ctx) {
330		mmu->domains[ret] = domain;
331		set_bit(ret, mmu->ctx);
332	} else
333		ret = -EBUSY;
334
335	spin_unlock_irqrestore(&mmu->lock, flags);
336
337	return ret;
338}
339
340static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
341				      unsigned int context_id)
342{
343	unsigned long flags;
344
345	spin_lock_irqsave(&mmu->lock, flags);
346
347	clear_bit(context_id, mmu->ctx);
348	mmu->domains[context_id] = NULL;
349
350	spin_unlock_irqrestore(&mmu->lock, flags);
351}
352
353static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
354{
355	u64 ttbr;
356	u32 tmp;
357
358	/* TTBR0 */
359	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
360	ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
361	ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
362
363	/*
364	 * TTBCR
365	 * We use long descriptors and allocate the whole 32-bit VA space to
366	 * TTBR0.
367	 */
368	if (domain->mmu->features->twobit_imttbcr_sl0)
369		tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
370	else
371		tmp = IMTTBCR_SL0_LVL_1;
372
373	if (domain->mmu->features->cache_snoop)
374		tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
375		       IMTTBCR_IRGN0_WB_WA;
376
377	ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
378
379	/* MAIR0 */
380	ipmmu_ctx_write_root(domain, IMMAIR0,
381			     domain->cfg.arm_lpae_s1_cfg.mair);
382
383	/* IMBUSCR */
384	if (domain->mmu->features->setup_imbuscr)
385		ipmmu_ctx_write_root(domain, IMBUSCR,
386				     ipmmu_ctx_read_root(domain, IMBUSCR) &
387				     ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
388
389	/*
390	 * IMSTR
391	 * Clear all interrupt flags.
392	 */
393	ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
394
395	/*
396	 * IMCTR
397	 * Enable the MMU and interrupt generation. The long-descriptor
398	 * translation table format doesn't use TEX remapping. Don't enable AF
399	 * software management as we have no use for it. Flush the TLB as
400	 * required when modifying the context registers.
401	 */
402	ipmmu_ctx_write_all(domain, IMCTR,
403			    IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
404}
405
406static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
407{
408	int ret;
409
410	/*
411	 * Allocate the page table operations.
412	 *
413	 * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
414	 * access, Long-descriptor format" that the NStable bit being set in a
415	 * table descriptor will result in the NStable and NS bits of all child
416	 * entries being ignored and considered as being set. The IPMMU seems
417	 * not to comply with this, as it generates a secure access page fault
418	 * if any of the NStable and NS bits isn't set when running in
419	 * non-secure mode.
420	 */
421	domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
422	domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
423	domain->cfg.ias = 32;
424	domain->cfg.oas = 40;
425	domain->cfg.tlb = &ipmmu_flush_ops;
426	domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
427	domain->io_domain.geometry.force_aperture = true;
428	/*
429	 * TODO: Add support for coherent walk through CCI with DVM and remove
430	 * cache handling. For now, delegate it to the io-pgtable code.
431	 */
432	domain->cfg.coherent_walk = false;
433	domain->cfg.iommu_dev = domain->mmu->root->dev;
434
435	/*
436	 * Find an unused context.
437	 */
438	ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
439	if (ret < 0)
440		return ret;
441
442	domain->context_id = ret;
443
444	domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
445					   domain);
446	if (!domain->iop) {
447		ipmmu_domain_free_context(domain->mmu->root,
448					  domain->context_id);
449		return -EINVAL;
450	}
451
452	ipmmu_domain_setup_context(domain);
453	return 0;
454}
455
456static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
457{
458	if (!domain->mmu)
459		return;
460
461	/*
462	 * Disable the context. Flush the TLB as required when modifying the
463	 * context registers.
464	 *
465	 * TODO: Is TLB flush really needed ?
466	 */
467	ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
468	ipmmu_tlb_sync(domain);
469	ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
470}
471
472/* -----------------------------------------------------------------------------
473 * Fault Handling
474 */
475
476static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
477{
478	const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
479	struct ipmmu_vmsa_device *mmu = domain->mmu;
480	unsigned long iova;
481	u32 status;
482
483	status = ipmmu_ctx_read_root(domain, IMSTR);
484	if (!(status & err_mask))
485		return IRQ_NONE;
486
487	iova = ipmmu_ctx_read_root(domain, IMELAR);
488	if (IS_ENABLED(CONFIG_64BIT))
489		iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
490
491	/*
492	 * Clear the error status flags. Unlike traditional interrupt flag
493	 * registers that must be cleared by writing 1, this status register
494	 * seems to require 0. The error address register must be read before,
495	 * otherwise its value will be 0.
496	 */
497	ipmmu_ctx_write_root(domain, IMSTR, 0);
498
499	/* Log fatal errors. */
500	if (status & IMSTR_MHIT)
501		dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
502				    iova);
503	if (status & IMSTR_ABORT)
504		dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
505				    iova);
506
507	if (!(status & (IMSTR_PF | IMSTR_TF)))
508		return IRQ_NONE;
509
510	/*
511	 * Try to handle page faults and translation faults.
512	 *
513	 * TODO: We need to look up the faulty device based on the I/O VA. Use
514	 * the IOMMU device for now.
515	 */
516	if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
517		return IRQ_HANDLED;
518
519	dev_err_ratelimited(mmu->dev,
520			    "Unhandled fault: status 0x%08x iova 0x%lx\n",
521			    status, iova);
522
523	return IRQ_HANDLED;
524}
525
526static irqreturn_t ipmmu_irq(int irq, void *dev)
527{
528	struct ipmmu_vmsa_device *mmu = dev;
529	irqreturn_t status = IRQ_NONE;
530	unsigned int i;
531	unsigned long flags;
532
533	spin_lock_irqsave(&mmu->lock, flags);
534
535	/*
536	 * Check interrupts for all active contexts.
537	 */
538	for (i = 0; i < mmu->num_ctx; i++) {
539		if (!mmu->domains[i])
540			continue;
541		if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
542			status = IRQ_HANDLED;
543	}
544
545	spin_unlock_irqrestore(&mmu->lock, flags);
546
547	return status;
548}
549
550/* -----------------------------------------------------------------------------
551 * IOMMU Operations
552 */
553
554static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
555{
556	struct ipmmu_vmsa_domain *domain;
557
558	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
559		return NULL;
560
561	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
562	if (!domain)
563		return NULL;
564
565	mutex_init(&domain->mutex);
566
567	return &domain->io_domain;
568}
569
570static void ipmmu_domain_free(struct iommu_domain *io_domain)
571{
572	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
573
574	/*
575	 * Free the domain resources. We assume that all devices have already
576	 * been detached.
577	 */
578	ipmmu_domain_destroy_context(domain);
579	free_io_pgtable_ops(domain->iop);
580	kfree(domain);
581}
582
583static int ipmmu_attach_device(struct iommu_domain *io_domain,
584			       struct device *dev)
585{
586	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
587	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
588	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
589	unsigned int i;
590	int ret = 0;
591
592	if (!mmu) {
593		dev_err(dev, "Cannot attach to IPMMU\n");
594		return -ENXIO;
595	}
596
597	mutex_lock(&domain->mutex);
598
599	if (!domain->mmu) {
600		/* The domain hasn't been used yet, initialize it. */
601		domain->mmu = mmu;
602		ret = ipmmu_domain_init_context(domain);
603		if (ret < 0) {
604			dev_err(dev, "Unable to initialize IPMMU context\n");
605			domain->mmu = NULL;
606		} else {
607			dev_info(dev, "Using IPMMU context %u\n",
608				 domain->context_id);
609		}
610	} else if (domain->mmu != mmu) {
611		/*
612		 * Something is wrong, we can't attach two devices using
613		 * different IOMMUs to the same domain.
614		 */
615		ret = -EINVAL;
616	} else
617		dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
618
619	mutex_unlock(&domain->mutex);
620
621	if (ret < 0)
622		return ret;
623
624	for (i = 0; i < fwspec->num_ids; ++i)
625		ipmmu_utlb_enable(domain, fwspec->ids[i]);
626
627	return 0;
628}
629
630static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
631		     phys_addr_t paddr, size_t pgsize, size_t pgcount,
632		     int prot, gfp_t gfp, size_t *mapped)
633{
634	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
635
636	return domain->iop->map_pages(domain->iop, iova, paddr, pgsize, pgcount,
637				      prot, gfp, mapped);
638}
639
640static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
641			  size_t pgsize, size_t pgcount,
642			  struct iommu_iotlb_gather *gather)
643{
644	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
645
646	return domain->iop->unmap_pages(domain->iop, iova, pgsize, pgcount, gather);
647}
648
649static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
650{
651	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
652
653	if (domain->mmu)
654		ipmmu_tlb_flush_all(domain);
655}
656
657static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
658			     struct iommu_iotlb_gather *gather)
659{
660	ipmmu_flush_iotlb_all(io_domain);
661}
662
663static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
664				      dma_addr_t iova)
665{
666	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
667
668	/* TODO: Is locking needed ? */
669
670	return domain->iop->iova_to_phys(domain->iop, iova);
671}
672
673static int ipmmu_init_platform_device(struct device *dev,
674				      struct of_phandle_args *args)
675{
676	struct platform_device *ipmmu_pdev;
677
678	ipmmu_pdev = of_find_device_by_node(args->np);
679	if (!ipmmu_pdev)
680		return -ENODEV;
681
682	dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
683
684	return 0;
685}
686
687static const struct soc_device_attribute soc_needs_opt_in[] = {
688	{ .family = "R-Car Gen3", },
689	{ .family = "R-Car Gen4", },
690	{ .family = "RZ/G2", },
691	{ /* sentinel */ }
692};
693
694static const struct soc_device_attribute soc_denylist[] = {
695	{ .soc_id = "r8a774a1", },
696	{ .soc_id = "r8a7795", .revision = "ES2.*" },
697	{ .soc_id = "r8a7796", },
698	{ /* sentinel */ }
699};
700
701static const char * const devices_allowlist[] = {
702	"ee100000.mmc",
703	"ee120000.mmc",
704	"ee140000.mmc",
705	"ee160000.mmc"
706};
707
708static bool ipmmu_device_is_allowed(struct device *dev)
709{
710	unsigned int i;
711
712	/*
713	 * R-Car Gen3/4 and RZ/G2 use the allow list to opt-in devices.
714	 * For Other SoCs, this returns true anyway.
715	 */
716	if (!soc_device_match(soc_needs_opt_in))
717		return true;
718
719	/* Check whether this SoC can use the IPMMU correctly or not */
720	if (soc_device_match(soc_denylist))
721		return false;
722
723	/* Check whether this device is a PCI device */
724	if (dev_is_pci(dev))
725		return true;
726
727	/* Check whether this device can work with the IPMMU */
728	for (i = 0; i < ARRAY_SIZE(devices_allowlist); i++) {
729		if (!strcmp(dev_name(dev), devices_allowlist[i]))
730			return true;
731	}
732
733	/* Otherwise, do not allow use of IPMMU */
734	return false;
735}
736
737static int ipmmu_of_xlate(struct device *dev,
738			  struct of_phandle_args *spec)
739{
740	if (!ipmmu_device_is_allowed(dev))
741		return -ENODEV;
742
743	iommu_fwspec_add_ids(dev, spec->args, 1);
744
745	/* Initialize once - xlate() will call multiple times */
746	if (to_ipmmu(dev))
747		return 0;
748
749	return ipmmu_init_platform_device(dev, spec);
750}
751
752static int ipmmu_init_arm_mapping(struct device *dev)
753{
754	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
755	int ret;
756
757	/*
758	 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
759	 * VAs. This will allocate a corresponding IOMMU domain.
760	 *
761	 * TODO:
762	 * - Create one mapping per context (TLB).
763	 * - Make the mapping size configurable ? We currently use a 2GB mapping
764	 *   at a 1GB offset to ensure that NULL VAs will fault.
765	 */
766	if (!mmu->mapping) {
767		struct dma_iommu_mapping *mapping;
768
769		mapping = arm_iommu_create_mapping(&platform_bus_type,
770						   SZ_1G, SZ_2G);
771		if (IS_ERR(mapping)) {
772			dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
773			ret = PTR_ERR(mapping);
774			goto error;
775		}
776
777		mmu->mapping = mapping;
778	}
779
780	/* Attach the ARM VA mapping to the device. */
781	ret = arm_iommu_attach_device(dev, mmu->mapping);
782	if (ret < 0) {
783		dev_err(dev, "Failed to attach device to VA mapping\n");
784		goto error;
785	}
786
787	return 0;
788
789error:
790	if (mmu->mapping)
791		arm_iommu_release_mapping(mmu->mapping);
792
793	return ret;
794}
795
796static struct iommu_device *ipmmu_probe_device(struct device *dev)
797{
798	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
799
800	/*
801	 * Only let through devices that have been verified in xlate()
802	 */
803	if (!mmu)
804		return ERR_PTR(-ENODEV);
805
806	return &mmu->iommu;
807}
808
809static void ipmmu_probe_finalize(struct device *dev)
810{
811	int ret = 0;
812
813	if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
814		ret = ipmmu_init_arm_mapping(dev);
815
816	if (ret)
817		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
818}
819
820static void ipmmu_release_device(struct device *dev)
821{
822	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
823	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
824	unsigned int i;
825
826	for (i = 0; i < fwspec->num_ids; ++i) {
827		unsigned int utlb = fwspec->ids[i];
828
829		ipmmu_imuctr_write(mmu, utlb, 0);
830		mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
831	}
832
833	arm_iommu_release_mapping(mmu->mapping);
834}
835
836static struct iommu_group *ipmmu_find_group(struct device *dev)
837{
838	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
839	struct iommu_group *group;
840
841	if (mmu->group)
842		return iommu_group_ref_get(mmu->group);
843
844	group = iommu_group_alloc();
845	if (!IS_ERR(group))
846		mmu->group = group;
847
848	return group;
849}
850
851static const struct iommu_ops ipmmu_ops = {
852	.domain_alloc = ipmmu_domain_alloc,
853	.probe_device = ipmmu_probe_device,
854	.release_device = ipmmu_release_device,
855	.probe_finalize = ipmmu_probe_finalize,
856	.device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
857			? generic_device_group : ipmmu_find_group,
858	.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
859	.of_xlate = ipmmu_of_xlate,
860	.default_domain_ops = &(const struct iommu_domain_ops) {
861		.attach_dev	= ipmmu_attach_device,
862		.map_pages	= ipmmu_map,
863		.unmap_pages	= ipmmu_unmap,
864		.flush_iotlb_all = ipmmu_flush_iotlb_all,
865		.iotlb_sync	= ipmmu_iotlb_sync,
866		.iova_to_phys	= ipmmu_iova_to_phys,
867		.free		= ipmmu_domain_free,
868	}
869};
870
871/* -----------------------------------------------------------------------------
872 * Probe/remove and init
873 */
874
875static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
876{
877	unsigned int i;
878
879	/* Disable all contexts. */
880	for (i = 0; i < mmu->num_ctx; ++i)
881		ipmmu_ctx_write(mmu, i, IMCTR, 0);
882}
883
884static const struct ipmmu_features ipmmu_features_default = {
885	.use_ns_alias_offset = true,
886	.has_cache_leaf_nodes = false,
887	.number_of_contexts = 1, /* software only tested with one context */
888	.num_utlbs = 32,
889	.setup_imbuscr = true,
890	.twobit_imttbcr_sl0 = false,
891	.reserved_context = false,
892	.cache_snoop = true,
893	.ctx_offset_base = 0,
894	.ctx_offset_stride = 0x40,
895	.utlb_offset_base = 0,
896};
897
898static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
899	.use_ns_alias_offset = false,
900	.has_cache_leaf_nodes = true,
901	.number_of_contexts = 8,
902	.num_utlbs = 48,
903	.setup_imbuscr = false,
904	.twobit_imttbcr_sl0 = true,
905	.reserved_context = true,
906	.cache_snoop = false,
907	.ctx_offset_base = 0,
908	.ctx_offset_stride = 0x40,
909	.utlb_offset_base = 0,
910};
911
912static const struct ipmmu_features ipmmu_features_rcar_gen4 = {
913	.use_ns_alias_offset = false,
914	.has_cache_leaf_nodes = true,
915	.number_of_contexts = 16,
916	.num_utlbs = 64,
917	.setup_imbuscr = false,
918	.twobit_imttbcr_sl0 = true,
919	.reserved_context = true,
920	.cache_snoop = false,
921	.ctx_offset_base = 0x10000,
922	.ctx_offset_stride = 0x1040,
923	.utlb_offset_base = 0x3000,
924};
925
926static const struct of_device_id ipmmu_of_ids[] = {
927	{
928		.compatible = "renesas,ipmmu-vmsa",
929		.data = &ipmmu_features_default,
930	}, {
931		.compatible = "renesas,ipmmu-r8a774a1",
932		.data = &ipmmu_features_rcar_gen3,
933	}, {
934		.compatible = "renesas,ipmmu-r8a774b1",
935		.data = &ipmmu_features_rcar_gen3,
936	}, {
937		.compatible = "renesas,ipmmu-r8a774c0",
938		.data = &ipmmu_features_rcar_gen3,
939	}, {
940		.compatible = "renesas,ipmmu-r8a774e1",
941		.data = &ipmmu_features_rcar_gen3,
942	}, {
943		.compatible = "renesas,ipmmu-r8a7795",
944		.data = &ipmmu_features_rcar_gen3,
945	}, {
946		.compatible = "renesas,ipmmu-r8a7796",
947		.data = &ipmmu_features_rcar_gen3,
948	}, {
949		.compatible = "renesas,ipmmu-r8a77961",
950		.data = &ipmmu_features_rcar_gen3,
951	}, {
952		.compatible = "renesas,ipmmu-r8a77965",
953		.data = &ipmmu_features_rcar_gen3,
954	}, {
955		.compatible = "renesas,ipmmu-r8a77970",
956		.data = &ipmmu_features_rcar_gen3,
957	}, {
958		.compatible = "renesas,ipmmu-r8a77980",
959		.data = &ipmmu_features_rcar_gen3,
960	}, {
961		.compatible = "renesas,ipmmu-r8a77990",
962		.data = &ipmmu_features_rcar_gen3,
963	}, {
964		.compatible = "renesas,ipmmu-r8a77995",
965		.data = &ipmmu_features_rcar_gen3,
966	}, {
967		.compatible = "renesas,ipmmu-r8a779a0",
968		.data = &ipmmu_features_rcar_gen4,
969	}, {
970		.compatible = "renesas,rcar-gen4-ipmmu-vmsa",
971		.data = &ipmmu_features_rcar_gen4,
972	}, {
973		/* Terminator */
974	},
975};
976
977static int ipmmu_probe(struct platform_device *pdev)
978{
979	struct ipmmu_vmsa_device *mmu;
980	struct resource *res;
981	int irq;
982	int ret;
983
984	mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
985	if (!mmu) {
986		dev_err(&pdev->dev, "cannot allocate device data\n");
987		return -ENOMEM;
988	}
989
990	mmu->dev = &pdev->dev;
991	spin_lock_init(&mmu->lock);
992	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
993	mmu->features = of_device_get_match_data(&pdev->dev);
994	memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
995	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
996	if (ret)
997		return ret;
998
999	/* Map I/O memory and request IRQ. */
1000	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1001	mmu->base = devm_ioremap_resource(&pdev->dev, res);
1002	if (IS_ERR(mmu->base))
1003		return PTR_ERR(mmu->base);
1004
1005	/*
1006	 * The IPMMU has two register banks, for secure and non-secure modes.
1007	 * The bank mapped at the beginning of the IPMMU address space
1008	 * corresponds to the running mode of the CPU. When running in secure
1009	 * mode the non-secure register bank is also available at an offset.
1010	 *
1011	 * Secure mode operation isn't clearly documented and is thus currently
1012	 * not implemented in the driver. Furthermore, preliminary tests of
1013	 * non-secure operation with the main register bank were not successful.
1014	 * Offset the registers base unconditionally to point to the non-secure
1015	 * alias space for now.
1016	 */
1017	if (mmu->features->use_ns_alias_offset)
1018		mmu->base += IM_NS_ALIAS_OFFSET;
1019
1020	mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1021
1022	/*
1023	 * Determine if this IPMMU instance is a root device by checking for
1024	 * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1025	 */
1026	if (!mmu->features->has_cache_leaf_nodes ||
1027	    !of_property_present(pdev->dev.of_node, "renesas,ipmmu-main"))
1028		mmu->root = mmu;
1029	else
1030		mmu->root = ipmmu_find_root();
1031
1032	/*
1033	 * Wait until the root device has been registered for sure.
1034	 */
1035	if (!mmu->root)
1036		return -EPROBE_DEFER;
1037
1038	/* Root devices have mandatory IRQs */
1039	if (ipmmu_is_root(mmu)) {
1040		irq = platform_get_irq(pdev, 0);
1041		if (irq < 0)
1042			return irq;
1043
1044		ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1045				       dev_name(&pdev->dev), mmu);
1046		if (ret < 0) {
1047			dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1048			return ret;
1049		}
1050
1051		ipmmu_device_reset(mmu);
1052
1053		if (mmu->features->reserved_context) {
1054			dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1055			set_bit(0, mmu->ctx);
1056		}
1057	}
1058
1059	/*
1060	 * Register the IPMMU to the IOMMU subsystem in the following cases:
1061	 * - R-Car Gen2 IPMMU (all devices registered)
1062	 * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1063	 */
1064	if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1065		ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1066					     dev_name(&pdev->dev));
1067		if (ret)
1068			return ret;
1069
1070		ret = iommu_device_register(&mmu->iommu, &ipmmu_ops, &pdev->dev);
1071		if (ret)
1072			return ret;
1073	}
1074
1075	/*
1076	 * We can't create the ARM mapping here as it requires the bus to have
1077	 * an IOMMU, which only happens when bus_set_iommu() is called in
1078	 * ipmmu_init() after the probe function returns.
1079	 */
1080
1081	platform_set_drvdata(pdev, mmu);
1082
1083	return 0;
1084}
1085
1086static void ipmmu_remove(struct platform_device *pdev)
1087{
1088	struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1089
1090	iommu_device_sysfs_remove(&mmu->iommu);
1091	iommu_device_unregister(&mmu->iommu);
1092
1093	arm_iommu_release_mapping(mmu->mapping);
1094
1095	ipmmu_device_reset(mmu);
1096}
1097
1098#ifdef CONFIG_PM_SLEEP
1099static int ipmmu_resume_noirq(struct device *dev)
1100{
1101	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1102	unsigned int i;
1103
1104	/* Reset root MMU and restore contexts */
1105	if (ipmmu_is_root(mmu)) {
1106		ipmmu_device_reset(mmu);
1107
1108		for (i = 0; i < mmu->num_ctx; i++) {
1109			if (!mmu->domains[i])
1110				continue;
1111
1112			ipmmu_domain_setup_context(mmu->domains[i]);
1113		}
1114	}
1115
1116	/* Re-enable active micro-TLBs */
1117	for (i = 0; i < mmu->features->num_utlbs; i++) {
1118		if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1119			continue;
1120
1121		ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1122	}
1123
1124	return 0;
1125}
1126
1127static const struct dev_pm_ops ipmmu_pm  = {
1128	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1129};
1130#define DEV_PM_OPS	&ipmmu_pm
1131#else
1132#define DEV_PM_OPS	NULL
1133#endif /* CONFIG_PM_SLEEP */
1134
1135static struct platform_driver ipmmu_driver = {
1136	.driver = {
1137		.name = "ipmmu-vmsa",
1138		.of_match_table = of_match_ptr(ipmmu_of_ids),
1139		.pm = DEV_PM_OPS,
1140	},
1141	.probe = ipmmu_probe,
1142	.remove_new = ipmmu_remove,
1143};
1144builtin_platform_driver(ipmmu_driver);
1145