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