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   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-iommu.h>
  12#include <linux/dma-mapping.h>
  13#include <linux/err.h>
  14#include <linux/export.h>
  15#include <linux/init.h>
  16#include <linux/interrupt.h>
  17#include <linux/io.h>
  18#include <linux/io-pgtable.h>
  19#include <linux/iommu.h>
  20#include <linux/of.h>
  21#include <linux/of_device.h>
  22#include <linux/of_iommu.h>
  23#include <linux/of_platform.h>
  24#include <linux/platform_device.h>
  25#include <linux/sizes.h>
  26#include <linux/slab.h>
  27#include <linux/sys_soc.h>
  28
  29#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
  30#include <asm/dma-iommu.h>
  31#else
  32#define arm_iommu_create_mapping(...)	NULL
  33#define arm_iommu_attach_device(...)	-ENODEV
  34#define arm_iommu_release_mapping(...)	do {} while (0)
  35#define arm_iommu_detach_device(...)	do {} while (0)
  36#endif
  37
  38#define IPMMU_CTX_MAX		8U
  39#define IPMMU_CTX_INVALID	-1
  40
  41#define IPMMU_UTLB_MAX		48U
  42
  43struct ipmmu_features {
  44	bool use_ns_alias_offset;
  45	bool has_cache_leaf_nodes;
  46	unsigned int number_of_contexts;
  47	unsigned int num_utlbs;
  48	bool setup_imbuscr;
  49	bool twobit_imttbcr_sl0;
  50	bool reserved_context;
  51	bool cache_snoop;
  52	unsigned int ctx_offset_base;
  53	unsigned int ctx_offset_stride;
  54	unsigned int utlb_offset_base;
  55};
  56
  57struct ipmmu_vmsa_device {
  58	struct device *dev;
  59	void __iomem *base;
  60	struct iommu_device iommu;
  61	struct ipmmu_vmsa_device *root;
  62	const struct ipmmu_features *features;
  63	unsigned int num_ctx;
  64	spinlock_t lock;			/* Protects ctx and domains[] */
  65	DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  66	struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  67	s8 utlb_ctx[IPMMU_UTLB_MAX];
  68
  69	struct iommu_group *group;
  70	struct dma_iommu_mapping *mapping;
  71};
  72
  73struct ipmmu_vmsa_domain {
  74	struct ipmmu_vmsa_device *mmu;
  75	struct iommu_domain io_domain;
  76
  77	struct io_pgtable_cfg cfg;
  78	struct io_pgtable_ops *iop;
  79
  80	unsigned int context_id;
  81	struct mutex mutex;			/* Protects mappings */
  82};
  83
  84static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  85{
  86	return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  87}
  88
  89static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  90{
  91	return dev_iommu_priv_get(dev);
  92}
  93
  94#define TLB_LOOP_TIMEOUT		100	/* 100us */
  95
  96/* -----------------------------------------------------------------------------
  97 * Registers Definition
  98 */
  99
 100#define IM_NS_ALIAS_OFFSET		0x800
 101
 102/* MMU "context" registers */
 103#define IMCTR				0x0000		/* R-Car Gen2/3 */
 104#define IMCTR_INTEN			(1 << 2)	/* R-Car Gen2/3 */
 105#define IMCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
 106#define IMCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
 107
 108#define IMTTBCR				0x0008		/* R-Car Gen2/3 */
 109#define IMTTBCR_EAE			(1 << 31)	/* R-Car Gen2/3 */
 110#define IMTTBCR_SH0_INNER_SHAREABLE	(3 << 12)	/* R-Car Gen2 only */
 111#define IMTTBCR_ORGN0_WB_WA		(1 << 10)	/* R-Car Gen2 only */
 112#define IMTTBCR_IRGN0_WB_WA		(1 << 8)	/* R-Car Gen2 only */
 113#define IMTTBCR_SL0_TWOBIT_LVL_1	(2 << 6)	/* R-Car Gen3 only */
 114#define IMTTBCR_SL0_LVL_1		(1 << 4)	/* R-Car Gen2 only */
 115
 116#define IMBUSCR				0x000c		/* R-Car Gen2 only */
 117#define IMBUSCR_DVM			(1 << 2)	/* R-Car Gen2 only */
 118#define IMBUSCR_BUSSEL_MASK		(3 << 0)	/* R-Car Gen2 only */
 119
 120#define IMTTLBR0			0x0010		/* R-Car Gen2/3 */
 121#define IMTTUBR0			0x0014		/* R-Car Gen2/3 */
 122
 123#define IMSTR				0x0020		/* R-Car Gen2/3 */
 124#define IMSTR_MHIT			(1 << 4)	/* R-Car Gen2/3 */
 125#define IMSTR_ABORT			(1 << 2)	/* R-Car Gen2/3 */
 126#define IMSTR_PF			(1 << 1)	/* R-Car Gen2/3 */
 127#define IMSTR_TF			(1 << 0)	/* R-Car Gen2/3 */
 128
 129#define IMMAIR0				0x0028		/* R-Car Gen2/3 */
 130
 131#define IMELAR				0x0030		/* R-Car Gen2/3, IMEAR on R-Car Gen2 */
 132#define IMEUAR				0x0034		/* R-Car Gen3 only */
 133
 134/* uTLB registers */
 135#define IMUCTR(n)			((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
 136#define IMUCTR0(n)			(0x0300 + ((n) * 16))		/* R-Car Gen2/3 */
 137#define IMUCTR32(n)			(0x0600 + (((n) - 32) * 16))	/* R-Car Gen3 only */
 138#define IMUCTR_TTSEL_MMU(n)		((n) << 4)	/* R-Car Gen2/3 */
 139#define IMUCTR_FLUSH			(1 << 1)	/* R-Car Gen2/3 */
 140#define IMUCTR_MMUEN			(1 << 0)	/* R-Car Gen2/3 */
 141
 142#define IMUASID(n)			((n) < 32 ? IMUASID0(n) : IMUASID32(n))
 143#define IMUASID0(n)			(0x0308 + ((n) * 16))		/* R-Car Gen2/3 */
 144#define IMUASID32(n)			(0x0608 + (((n) - 32) * 16))	/* R-Car Gen3 only */
 145
 146/* -----------------------------------------------------------------------------
 147 * Root device handling
 148 */
 149
 150static struct platform_driver ipmmu_driver;
 151
 152static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 153{
 154	return mmu->root == mmu;
 155}
 156
 157static int __ipmmu_check_device(struct device *dev, void *data)
 158{
 159	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 160	struct ipmmu_vmsa_device **rootp = data;
 161
 162	if (ipmmu_is_root(mmu))
 163		*rootp = mmu;
 164
 165	return 0;
 166}
 167
 168static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 169{
 170	struct ipmmu_vmsa_device *root = NULL;
 171
 172	return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 173				      __ipmmu_check_device) == 0 ? root : NULL;
 174}
 175
 176/* -----------------------------------------------------------------------------
 177 * Read/Write Access
 178 */
 179
 180static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 181{
 182	return ioread32(mmu->base + offset);
 183}
 184
 185static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 186			u32 data)
 187{
 188	iowrite32(data, mmu->base + offset);
 189}
 190
 191static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
 192				  unsigned int context_id, unsigned int reg)
 193{
 194	return mmu->features->ctx_offset_base +
 195	       context_id * mmu->features->ctx_offset_stride + reg;
 196}
 197
 198static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
 199			  unsigned int context_id, unsigned int reg)
 200{
 201	return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
 202}
 203
 204static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
 205			    unsigned int context_id, unsigned int reg, u32 data)
 206{
 207	ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
 208}
 209
 210static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 211			       unsigned int reg)
 212{
 213	return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
 214}
 215
 216static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 217				 unsigned int reg, u32 data)
 218{
 219	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 220}
 221
 222static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 223				unsigned int reg, u32 data)
 224{
 225	if (domain->mmu != domain->mmu->root)
 226		ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
 227
 228	ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 229}
 230
 231static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
 232{
 233	return mmu->features->utlb_offset_base + reg;
 234}
 235
 236static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
 237				unsigned int utlb, u32 data)
 238{
 239	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
 240}
 241
 242static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
 243			       unsigned int utlb, u32 data)
 244{
 245	ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
 246}
 247
 248/* -----------------------------------------------------------------------------
 249 * TLB and microTLB Management
 250 */
 251
 252/* Wait for any pending TLB invalidations to complete */
 253static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 254{
 255	unsigned int count = 0;
 256
 257	while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 258		cpu_relax();
 259		if (++count == TLB_LOOP_TIMEOUT) {
 260			dev_err_ratelimited(domain->mmu->dev,
 261			"TLB sync timed out -- MMU may be deadlocked\n");
 262			return;
 263		}
 264		udelay(1);
 265	}
 266}
 267
 268static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 269{
 270	u32 reg;
 271
 272	reg = ipmmu_ctx_read_root(domain, IMCTR);
 273	reg |= IMCTR_FLUSH;
 274	ipmmu_ctx_write_all(domain, IMCTR, reg);
 275
 276	ipmmu_tlb_sync(domain);
 277}
 278
 279/*
 280 * Enable MMU translation for the microTLB.
 281 */
 282static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 283			      unsigned int utlb)
 284{
 285	struct ipmmu_vmsa_device *mmu = domain->mmu;
 286
 287	/*
 288	 * TODO: Reference-count the microTLB as several bus masters can be
 289	 * connected to the same microTLB.
 290	 */
 291
 292	/* TODO: What should we set the ASID to ? */
 293	ipmmu_imuasid_write(mmu, utlb, 0);
 294	/* TODO: Do we need to flush the microTLB ? */
 295	ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
 296				      IMUCTR_FLUSH | IMUCTR_MMUEN);
 297	mmu->utlb_ctx[utlb] = domain->context_id;
 298}
 299
 300/*
 301 * Disable MMU translation for the microTLB.
 302 */
 303static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 304			       unsigned int utlb)
 305{
 306	struct ipmmu_vmsa_device *mmu = domain->mmu;
 307
 308	ipmmu_imuctr_write(mmu, utlb, 0);
 309	mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
 310}
 311
 312static void ipmmu_tlb_flush_all(void *cookie)
 313{
 314	struct ipmmu_vmsa_domain *domain = cookie;
 315
 316	ipmmu_tlb_invalidate(domain);
 317}
 318
 319static void ipmmu_tlb_flush(unsigned long iova, size_t size,
 320				size_t granule, void *cookie)
 321{
 322	ipmmu_tlb_flush_all(cookie);
 323}
 324
 325static const struct iommu_flush_ops ipmmu_flush_ops = {
 326	.tlb_flush_all = ipmmu_tlb_flush_all,
 327	.tlb_flush_walk = ipmmu_tlb_flush,
 328	.tlb_flush_leaf = ipmmu_tlb_flush,
 329};
 330
 331/* -----------------------------------------------------------------------------
 332 * Domain/Context Management
 333 */
 334
 335static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 336					 struct ipmmu_vmsa_domain *domain)
 337{
 338	unsigned long flags;
 339	int ret;
 340
 341	spin_lock_irqsave(&mmu->lock, flags);
 342
 343	ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 344	if (ret != mmu->num_ctx) {
 345		mmu->domains[ret] = domain;
 346		set_bit(ret, mmu->ctx);
 347	} else
 348		ret = -EBUSY;
 349
 350	spin_unlock_irqrestore(&mmu->lock, flags);
 351
 352	return ret;
 353}
 354
 355static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 356				      unsigned int context_id)
 357{
 358	unsigned long flags;
 359
 360	spin_lock_irqsave(&mmu->lock, flags);
 361
 362	clear_bit(context_id, mmu->ctx);
 363	mmu->domains[context_id] = NULL;
 364
 365	spin_unlock_irqrestore(&mmu->lock, flags);
 366}
 367
 368static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
 369{
 370	u64 ttbr;
 371	u32 tmp;
 372
 373	/* TTBR0 */
 374	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
 375	ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 376	ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 377
 378	/*
 379	 * TTBCR
 380	 * We use long descriptors and allocate the whole 32-bit VA space to
 381	 * TTBR0.
 382	 */
 383	if (domain->mmu->features->twobit_imttbcr_sl0)
 384		tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 385	else
 386		tmp = IMTTBCR_SL0_LVL_1;
 387
 388	if (domain->mmu->features->cache_snoop)
 389		tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 390		       IMTTBCR_IRGN0_WB_WA;
 391
 392	ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
 393
 394	/* MAIR0 */
 395	ipmmu_ctx_write_root(domain, IMMAIR0,
 396			     domain->cfg.arm_lpae_s1_cfg.mair);
 397
 398	/* IMBUSCR */
 399	if (domain->mmu->features->setup_imbuscr)
 400		ipmmu_ctx_write_root(domain, IMBUSCR,
 401				     ipmmu_ctx_read_root(domain, IMBUSCR) &
 402				     ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 403
 404	/*
 405	 * IMSTR
 406	 * Clear all interrupt flags.
 407	 */
 408	ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 409
 410	/*
 411	 * IMCTR
 412	 * Enable the MMU and interrupt generation. The long-descriptor
 413	 * translation table format doesn't use TEX remapping. Don't enable AF
 414	 * software management as we have no use for it. Flush the TLB as
 415	 * required when modifying the context registers.
 416	 */
 417	ipmmu_ctx_write_all(domain, IMCTR,
 418			    IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 419}
 420
 421static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 422{
 423	int ret;
 424
 425	/*
 426	 * Allocate the page table operations.
 427	 *
 428	 * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 429	 * access, Long-descriptor format" that the NStable bit being set in a
 430	 * table descriptor will result in the NStable and NS bits of all child
 431	 * entries being ignored and considered as being set. The IPMMU seems
 432	 * not to comply with this, as it generates a secure access page fault
 433	 * if any of the NStable and NS bits isn't set when running in
 434	 * non-secure mode.
 435	 */
 436	domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 437	domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 438	domain->cfg.ias = 32;
 439	domain->cfg.oas = 40;
 440	domain->cfg.tlb = &ipmmu_flush_ops;
 441	domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 442	domain->io_domain.geometry.force_aperture = true;
 443	/*
 444	 * TODO: Add support for coherent walk through CCI with DVM and remove
 445	 * cache handling. For now, delegate it to the io-pgtable code.
 446	 */
 447	domain->cfg.coherent_walk = false;
 448	domain->cfg.iommu_dev = domain->mmu->root->dev;
 449
 450	/*
 451	 * Find an unused context.
 452	 */
 453	ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 454	if (ret < 0)
 455		return ret;
 456
 457	domain->context_id = ret;
 458
 459	domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 460					   domain);
 461	if (!domain->iop) {
 462		ipmmu_domain_free_context(domain->mmu->root,
 463					  domain->context_id);
 464		return -EINVAL;
 465	}
 466
 467	ipmmu_domain_setup_context(domain);
 468	return 0;
 469}
 470
 471static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 472{
 473	if (!domain->mmu)
 474		return;
 475
 476	/*
 477	 * Disable the context. Flush the TLB as required when modifying the
 478	 * context registers.
 479	 *
 480	 * TODO: Is TLB flush really needed ?
 481	 */
 482	ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 483	ipmmu_tlb_sync(domain);
 484	ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 485}
 486
 487/* -----------------------------------------------------------------------------
 488 * Fault Handling
 489 */
 490
 491static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 492{
 493	const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 494	struct ipmmu_vmsa_device *mmu = domain->mmu;
 495	unsigned long iova;
 496	u32 status;
 497
 498	status = ipmmu_ctx_read_root(domain, IMSTR);
 499	if (!(status & err_mask))
 500		return IRQ_NONE;
 501
 502	iova = ipmmu_ctx_read_root(domain, IMELAR);
 503	if (IS_ENABLED(CONFIG_64BIT))
 504		iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
 505
 506	/*
 507	 * Clear the error status flags. Unlike traditional interrupt flag
 508	 * registers that must be cleared by writing 1, this status register
 509	 * seems to require 0. The error address register must be read before,
 510	 * otherwise its value will be 0.
 511	 */
 512	ipmmu_ctx_write_root(domain, IMSTR, 0);
 513
 514	/* Log fatal errors. */
 515	if (status & IMSTR_MHIT)
 516		dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
 517				    iova);
 518	if (status & IMSTR_ABORT)
 519		dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
 520				    iova);
 521
 522	if (!(status & (IMSTR_PF | IMSTR_TF)))
 523		return IRQ_NONE;
 524
 525	/*
 526	 * Try to handle page faults and translation faults.
 527	 *
 528	 * TODO: We need to look up the faulty device based on the I/O VA. Use
 529	 * the IOMMU device for now.
 530	 */
 531	if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 532		return IRQ_HANDLED;
 533
 534	dev_err_ratelimited(mmu->dev,
 535			    "Unhandled fault: status 0x%08x iova 0x%lx\n",
 536			    status, iova);
 537
 538	return IRQ_HANDLED;
 539}
 540
 541static irqreturn_t ipmmu_irq(int irq, void *dev)
 542{
 543	struct ipmmu_vmsa_device *mmu = dev;
 544	irqreturn_t status = IRQ_NONE;
 545	unsigned int i;
 546	unsigned long flags;
 547
 548	spin_lock_irqsave(&mmu->lock, flags);
 549
 550	/*
 551	 * Check interrupts for all active contexts.
 552	 */
 553	for (i = 0; i < mmu->num_ctx; i++) {
 554		if (!mmu->domains[i])
 555			continue;
 556		if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 557			status = IRQ_HANDLED;
 558	}
 559
 560	spin_unlock_irqrestore(&mmu->lock, flags);
 561
 562	return status;
 563}
 564
 565/* -----------------------------------------------------------------------------
 566 * IOMMU Operations
 567 */
 568
 569static struct iommu_domain *__ipmmu_domain_alloc(unsigned type)
 570{
 571	struct ipmmu_vmsa_domain *domain;
 572
 573	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 574	if (!domain)
 575		return NULL;
 576
 577	mutex_init(&domain->mutex);
 578
 579	return &domain->io_domain;
 580}
 581
 582static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 583{
 584	struct iommu_domain *io_domain = NULL;
 585
 586	switch (type) {
 587	case IOMMU_DOMAIN_UNMANAGED:
 588		io_domain = __ipmmu_domain_alloc(type);
 589		break;
 590
 591	case IOMMU_DOMAIN_DMA:
 592		io_domain = __ipmmu_domain_alloc(type);
 593		if (io_domain && iommu_get_dma_cookie(io_domain)) {
 594			kfree(io_domain);
 595			io_domain = NULL;
 596		}
 597		break;
 598	}
 599
 600	return io_domain;
 601}
 602
 603static void ipmmu_domain_free(struct iommu_domain *io_domain)
 604{
 605	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 606
 607	/*
 608	 * Free the domain resources. We assume that all devices have already
 609	 * been detached.
 610	 */
 611	iommu_put_dma_cookie(io_domain);
 612	ipmmu_domain_destroy_context(domain);
 613	free_io_pgtable_ops(domain->iop);
 614	kfree(domain);
 615}
 616
 617static int ipmmu_attach_device(struct iommu_domain *io_domain,
 618			       struct device *dev)
 619{
 620	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 621	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 622	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 623	unsigned int i;
 624	int ret = 0;
 625
 626	if (!mmu) {
 627		dev_err(dev, "Cannot attach to IPMMU\n");
 628		return -ENXIO;
 629	}
 630
 631	mutex_lock(&domain->mutex);
 632
 633	if (!domain->mmu) {
 634		/* The domain hasn't been used yet, initialize it. */
 635		domain->mmu = mmu;
 636		ret = ipmmu_domain_init_context(domain);
 637		if (ret < 0) {
 638			dev_err(dev, "Unable to initialize IPMMU context\n");
 639			domain->mmu = NULL;
 640		} else {
 641			dev_info(dev, "Using IPMMU context %u\n",
 642				 domain->context_id);
 643		}
 644	} else if (domain->mmu != mmu) {
 645		/*
 646		 * Something is wrong, we can't attach two devices using
 647		 * different IOMMUs to the same domain.
 648		 */
 649		dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 650			dev_name(mmu->dev), dev_name(domain->mmu->dev));
 651		ret = -EINVAL;
 652	} else
 653		dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 654
 655	mutex_unlock(&domain->mutex);
 656
 657	if (ret < 0)
 658		return ret;
 659
 660	for (i = 0; i < fwspec->num_ids; ++i)
 661		ipmmu_utlb_enable(domain, fwspec->ids[i]);
 662
 663	return 0;
 664}
 665
 666static void ipmmu_detach_device(struct iommu_domain *io_domain,
 667				struct device *dev)
 668{
 669	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 670	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 671	unsigned int i;
 672
 673	for (i = 0; i < fwspec->num_ids; ++i)
 674		ipmmu_utlb_disable(domain, fwspec->ids[i]);
 675
 676	/*
 677	 * TODO: Optimize by disabling the context when no device is attached.
 678	 */
 679}
 680
 681static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 682		     phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 683{
 684	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 685
 686	if (!domain)
 687		return -ENODEV;
 688
 689	return domain->iop->map(domain->iop, iova, paddr, size, prot, gfp);
 690}
 691
 692static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 693			  size_t size, struct iommu_iotlb_gather *gather)
 694{
 695	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 696
 697	return domain->iop->unmap(domain->iop, iova, size, gather);
 698}
 699
 700static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
 701{
 702	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 703
 704	if (domain->mmu)
 705		ipmmu_tlb_flush_all(domain);
 706}
 707
 708static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
 709			     struct iommu_iotlb_gather *gather)
 710{
 711	ipmmu_flush_iotlb_all(io_domain);
 712}
 713
 714static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 715				      dma_addr_t iova)
 716{
 717	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 718
 719	/* TODO: Is locking needed ? */
 720
 721	return domain->iop->iova_to_phys(domain->iop, iova);
 722}
 723
 724static int ipmmu_init_platform_device(struct device *dev,
 725				      struct of_phandle_args *args)
 726{
 727	struct platform_device *ipmmu_pdev;
 728
 729	ipmmu_pdev = of_find_device_by_node(args->np);
 730	if (!ipmmu_pdev)
 731		return -ENODEV;
 732
 733	dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
 734
 735	return 0;
 736}
 737
 738static const struct soc_device_attribute soc_rcar_gen3[] = {
 739	{ .soc_id = "r8a774a1", },
 740	{ .soc_id = "r8a774b1", },
 741	{ .soc_id = "r8a774c0", },
 742	{ .soc_id = "r8a774e1", },
 743	{ .soc_id = "r8a7795", },
 744	{ .soc_id = "r8a77961", },
 745	{ .soc_id = "r8a7796", },
 746	{ .soc_id = "r8a77965", },
 747	{ .soc_id = "r8a77970", },
 748	{ .soc_id = "r8a77990", },
 749	{ .soc_id = "r8a77995", },
 750	{ /* sentinel */ }
 751};
 752
 753static const struct soc_device_attribute soc_rcar_gen3_whitelist[] = {
 754	{ .soc_id = "r8a774b1", },
 755	{ .soc_id = "r8a774c0", },
 756	{ .soc_id = "r8a774e1", },
 757	{ .soc_id = "r8a7795", .revision = "ES3.*" },
 758	{ .soc_id = "r8a77961", },
 759	{ .soc_id = "r8a77965", },
 760	{ .soc_id = "r8a77990", },
 761	{ .soc_id = "r8a77995", },
 762	{ /* sentinel */ }
 763};
 764
 765static const char * const rcar_gen3_slave_whitelist[] = {
 766};
 767
 768static bool ipmmu_slave_whitelist(struct device *dev)
 769{
 770	unsigned int i;
 771
 772	/*
 773	 * For R-Car Gen3 use a white list to opt-in slave devices.
 774	 * For Other SoCs, this returns true anyway.
 775	 */
 776	if (!soc_device_match(soc_rcar_gen3))
 777		return true;
 778
 779	/* Check whether this R-Car Gen3 can use the IPMMU correctly or not */
 780	if (!soc_device_match(soc_rcar_gen3_whitelist))
 781		return false;
 782
 783	/* Check whether this slave device can work with the IPMMU */
 784	for (i = 0; i < ARRAY_SIZE(rcar_gen3_slave_whitelist); i++) {
 785		if (!strcmp(dev_name(dev), rcar_gen3_slave_whitelist[i]))
 786			return true;
 787	}
 788
 789	/* Otherwise, do not allow use of IPMMU */
 790	return false;
 791}
 792
 793static int ipmmu_of_xlate(struct device *dev,
 794			  struct of_phandle_args *spec)
 795{
 796	if (!ipmmu_slave_whitelist(dev))
 797		return -ENODEV;
 798
 799	iommu_fwspec_add_ids(dev, spec->args, 1);
 800
 801	/* Initialize once - xlate() will call multiple times */
 802	if (to_ipmmu(dev))
 803		return 0;
 804
 805	return ipmmu_init_platform_device(dev, spec);
 806}
 807
 808static int ipmmu_init_arm_mapping(struct device *dev)
 809{
 810	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 811	int ret;
 812
 813	/*
 814	 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 815	 * VAs. This will allocate a corresponding IOMMU domain.
 816	 *
 817	 * TODO:
 818	 * - Create one mapping per context (TLB).
 819	 * - Make the mapping size configurable ? We currently use a 2GB mapping
 820	 *   at a 1GB offset to ensure that NULL VAs will fault.
 821	 */
 822	if (!mmu->mapping) {
 823		struct dma_iommu_mapping *mapping;
 824
 825		mapping = arm_iommu_create_mapping(&platform_bus_type,
 826						   SZ_1G, SZ_2G);
 827		if (IS_ERR(mapping)) {
 828			dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 829			ret = PTR_ERR(mapping);
 830			goto error;
 831		}
 832
 833		mmu->mapping = mapping;
 834	}
 835
 836	/* Attach the ARM VA mapping to the device. */
 837	ret = arm_iommu_attach_device(dev, mmu->mapping);
 838	if (ret < 0) {
 839		dev_err(dev, "Failed to attach device to VA mapping\n");
 840		goto error;
 841	}
 842
 843	return 0;
 844
 845error:
 846	if (mmu->mapping)
 847		arm_iommu_release_mapping(mmu->mapping);
 848
 849	return ret;
 850}
 851
 852static struct iommu_device *ipmmu_probe_device(struct device *dev)
 853{
 854	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 855
 856	/*
 857	 * Only let through devices that have been verified in xlate()
 858	 */
 859	if (!mmu)
 860		return ERR_PTR(-ENODEV);
 861
 862	return &mmu->iommu;
 863}
 864
 865static void ipmmu_probe_finalize(struct device *dev)
 866{
 867	int ret = 0;
 868
 869	if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
 870		ret = ipmmu_init_arm_mapping(dev);
 871
 872	if (ret)
 873		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
 874}
 875
 876static void ipmmu_release_device(struct device *dev)
 877{
 878	arm_iommu_detach_device(dev);
 879}
 880
 881static struct iommu_group *ipmmu_find_group(struct device *dev)
 882{
 883	struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 884	struct iommu_group *group;
 885
 886	if (mmu->group)
 887		return iommu_group_ref_get(mmu->group);
 888
 889	group = iommu_group_alloc();
 890	if (!IS_ERR(group))
 891		mmu->group = group;
 892
 893	return group;
 894}
 895
 896static const struct iommu_ops ipmmu_ops = {
 897	.domain_alloc = ipmmu_domain_alloc,
 898	.domain_free = ipmmu_domain_free,
 899	.attach_dev = ipmmu_attach_device,
 900	.detach_dev = ipmmu_detach_device,
 901	.map = ipmmu_map,
 902	.unmap = ipmmu_unmap,
 903	.flush_iotlb_all = ipmmu_flush_iotlb_all,
 904	.iotlb_sync = ipmmu_iotlb_sync,
 905	.iova_to_phys = ipmmu_iova_to_phys,
 906	.probe_device = ipmmu_probe_device,
 907	.release_device = ipmmu_release_device,
 908	.probe_finalize = ipmmu_probe_finalize,
 909	.device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
 910			? generic_device_group : ipmmu_find_group,
 911	.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 912	.of_xlate = ipmmu_of_xlate,
 913};
 914
 915/* -----------------------------------------------------------------------------
 916 * Probe/remove and init
 917 */
 918
 919static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 920{
 921	unsigned int i;
 922
 923	/* Disable all contexts. */
 924	for (i = 0; i < mmu->num_ctx; ++i)
 925		ipmmu_ctx_write(mmu, i, IMCTR, 0);
 926}
 927
 928static const struct ipmmu_features ipmmu_features_default = {
 929	.use_ns_alias_offset = true,
 930	.has_cache_leaf_nodes = false,
 931	.number_of_contexts = 1, /* software only tested with one context */
 932	.num_utlbs = 32,
 933	.setup_imbuscr = true,
 934	.twobit_imttbcr_sl0 = false,
 935	.reserved_context = false,
 936	.cache_snoop = true,
 937	.ctx_offset_base = 0,
 938	.ctx_offset_stride = 0x40,
 939	.utlb_offset_base = 0,
 940};
 941
 942static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 943	.use_ns_alias_offset = false,
 944	.has_cache_leaf_nodes = true,
 945	.number_of_contexts = 8,
 946	.num_utlbs = 48,
 947	.setup_imbuscr = false,
 948	.twobit_imttbcr_sl0 = true,
 949	.reserved_context = true,
 950	.cache_snoop = false,
 951	.ctx_offset_base = 0,
 952	.ctx_offset_stride = 0x40,
 953	.utlb_offset_base = 0,
 954};
 955
 956static const struct of_device_id ipmmu_of_ids[] = {
 957	{
 958		.compatible = "renesas,ipmmu-vmsa",
 959		.data = &ipmmu_features_default,
 960	}, {
 961		.compatible = "renesas,ipmmu-r8a774a1",
 962		.data = &ipmmu_features_rcar_gen3,
 963	}, {
 964		.compatible = "renesas,ipmmu-r8a774b1",
 965		.data = &ipmmu_features_rcar_gen3,
 966	}, {
 967		.compatible = "renesas,ipmmu-r8a774c0",
 968		.data = &ipmmu_features_rcar_gen3,
 969	}, {
 970		.compatible = "renesas,ipmmu-r8a774e1",
 971		.data = &ipmmu_features_rcar_gen3,
 972	}, {
 973		.compatible = "renesas,ipmmu-r8a7795",
 974		.data = &ipmmu_features_rcar_gen3,
 975	}, {
 976		.compatible = "renesas,ipmmu-r8a7796",
 977		.data = &ipmmu_features_rcar_gen3,
 978	}, {
 979		.compatible = "renesas,ipmmu-r8a77961",
 980		.data = &ipmmu_features_rcar_gen3,
 981	}, {
 982		.compatible = "renesas,ipmmu-r8a77965",
 983		.data = &ipmmu_features_rcar_gen3,
 984	}, {
 985		.compatible = "renesas,ipmmu-r8a77970",
 986		.data = &ipmmu_features_rcar_gen3,
 987	}, {
 988		.compatible = "renesas,ipmmu-r8a77990",
 989		.data = &ipmmu_features_rcar_gen3,
 990	}, {
 991		.compatible = "renesas,ipmmu-r8a77995",
 992		.data = &ipmmu_features_rcar_gen3,
 993	}, {
 994		/* Terminator */
 995	},
 996};
 997
 998static int ipmmu_probe(struct platform_device *pdev)
 999{
1000	struct ipmmu_vmsa_device *mmu;
1001	struct resource *res;
1002	int irq;
1003	int ret;
1004
1005	mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
1006	if (!mmu) {
1007		dev_err(&pdev->dev, "cannot allocate device data\n");
1008		return -ENOMEM;
1009	}
1010
1011	mmu->dev = &pdev->dev;
1012	spin_lock_init(&mmu->lock);
1013	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
1014	mmu->features = of_device_get_match_data(&pdev->dev);
1015	memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
1016	dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
1017
1018	/* Map I/O memory and request IRQ. */
1019	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1020	mmu->base = devm_ioremap_resource(&pdev->dev, res);
1021	if (IS_ERR(mmu->base))
1022		return PTR_ERR(mmu->base);
1023
1024	/*
1025	 * The IPMMU has two register banks, for secure and non-secure modes.
1026	 * The bank mapped at the beginning of the IPMMU address space
1027	 * corresponds to the running mode of the CPU. When running in secure
1028	 * mode the non-secure register bank is also available at an offset.
1029	 *
1030	 * Secure mode operation isn't clearly documented and is thus currently
1031	 * not implemented in the driver. Furthermore, preliminary tests of
1032	 * non-secure operation with the main register bank were not successful.
1033	 * Offset the registers base unconditionally to point to the non-secure
1034	 * alias space for now.
1035	 */
1036	if (mmu->features->use_ns_alias_offset)
1037		mmu->base += IM_NS_ALIAS_OFFSET;
1038
1039	mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1040
1041	/*
1042	 * Determine if this IPMMU instance is a root device by checking for
1043	 * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1044	 */
1045	if (!mmu->features->has_cache_leaf_nodes ||
1046	    !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
1047		mmu->root = mmu;
1048	else
1049		mmu->root = ipmmu_find_root();
1050
1051	/*
1052	 * Wait until the root device has been registered for sure.
1053	 */
1054	if (!mmu->root)
1055		return -EPROBE_DEFER;
1056
1057	/* Root devices have mandatory IRQs */
1058	if (ipmmu_is_root(mmu)) {
1059		irq = platform_get_irq(pdev, 0);
1060		if (irq < 0)
1061			return irq;
1062
1063		ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1064				       dev_name(&pdev->dev), mmu);
1065		if (ret < 0) {
1066			dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1067			return ret;
1068		}
1069
1070		ipmmu_device_reset(mmu);
1071
1072		if (mmu->features->reserved_context) {
1073			dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1074			set_bit(0, mmu->ctx);
1075		}
1076	}
1077
1078	/*
1079	 * Register the IPMMU to the IOMMU subsystem in the following cases:
1080	 * - R-Car Gen2 IPMMU (all devices registered)
1081	 * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1082	 */
1083	if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1084		ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1085					     dev_name(&pdev->dev));
1086		if (ret)
1087			return ret;
1088
1089		iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
1090		iommu_device_set_fwnode(&mmu->iommu,
1091					&pdev->dev.of_node->fwnode);
1092
1093		ret = iommu_device_register(&mmu->iommu);
1094		if (ret)
1095			return ret;
1096
1097#if defined(CONFIG_IOMMU_DMA)
1098		if (!iommu_present(&platform_bus_type))
1099			bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1100#endif
1101	}
1102
1103	/*
1104	 * We can't create the ARM mapping here as it requires the bus to have
1105	 * an IOMMU, which only happens when bus_set_iommu() is called in
1106	 * ipmmu_init() after the probe function returns.
1107	 */
1108
1109	platform_set_drvdata(pdev, mmu);
1110
1111	return 0;
1112}
1113
1114static int ipmmu_remove(struct platform_device *pdev)
1115{
1116	struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1117
1118	iommu_device_sysfs_remove(&mmu->iommu);
1119	iommu_device_unregister(&mmu->iommu);
1120
1121	arm_iommu_release_mapping(mmu->mapping);
1122
1123	ipmmu_device_reset(mmu);
1124
1125	return 0;
1126}
1127
1128#ifdef CONFIG_PM_SLEEP
1129static int ipmmu_resume_noirq(struct device *dev)
1130{
1131	struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1132	unsigned int i;
1133
1134	/* Reset root MMU and restore contexts */
1135	if (ipmmu_is_root(mmu)) {
1136		ipmmu_device_reset(mmu);
1137
1138		for (i = 0; i < mmu->num_ctx; i++) {
1139			if (!mmu->domains[i])
1140				continue;
1141
1142			ipmmu_domain_setup_context(mmu->domains[i]);
1143		}
1144	}
1145
1146	/* Re-enable active micro-TLBs */
1147	for (i = 0; i < mmu->features->num_utlbs; i++) {
1148		if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1149			continue;
1150
1151		ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1152	}
1153
1154	return 0;
1155}
1156
1157static const struct dev_pm_ops ipmmu_pm  = {
1158	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1159};
1160#define DEV_PM_OPS	&ipmmu_pm
1161#else
1162#define DEV_PM_OPS	NULL
1163#endif /* CONFIG_PM_SLEEP */
1164
1165static struct platform_driver ipmmu_driver = {
1166	.driver = {
1167		.name = "ipmmu-vmsa",
1168		.of_match_table = of_match_ptr(ipmmu_of_ids),
1169		.pm = DEV_PM_OPS,
1170	},
1171	.probe = ipmmu_probe,
1172	.remove	= ipmmu_remove,
1173};
1174
1175static int __init ipmmu_init(void)
1176{
1177	struct device_node *np;
1178	static bool setup_done;
1179	int ret;
1180
1181	if (setup_done)
1182		return 0;
1183
1184	np = of_find_matching_node(NULL, ipmmu_of_ids);
1185	if (!np)
1186		return 0;
1187
1188	of_node_put(np);
1189
1190	ret = platform_driver_register(&ipmmu_driver);
1191	if (ret < 0)
1192		return ret;
1193
1194#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1195	if (!iommu_present(&platform_bus_type))
1196		bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1197#endif
1198
1199	setup_done = true;
1200	return 0;
1201}
1202subsys_initcall(ipmmu_init);