1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2011,2016 Samsung Electronics Co., Ltd.
4 *		http://www.samsung.com
5 */
6
7#ifdef CONFIG_EXYNOS_IOMMU_DEBUG
8#define DEBUG
9#endif
10
11#include <linux/clk.h>
12#include <linux/dma-mapping.h>
13#include <linux/err.h>
14#include <linux/io.h>
15#include <linux/iommu.h>
16#include <linux/interrupt.h>
17#include <linux/kmemleak.h>
18#include <linux/list.h>
19#include <linux/of.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/pm_runtime.h>
23#include <linux/slab.h>
24
25typedef u32 sysmmu_iova_t;
26typedef u32 sysmmu_pte_t;
27static struct iommu_domain exynos_identity_domain;
28
29/* We do not consider super section mapping (16MB) */
30#define SECT_ORDER 20
31#define LPAGE_ORDER 16
32#define SPAGE_ORDER 12
33
34#define SECT_SIZE (1 << SECT_ORDER)
35#define LPAGE_SIZE (1 << LPAGE_ORDER)
36#define SPAGE_SIZE (1 << SPAGE_ORDER)
37
38#define SECT_MASK (~(SECT_SIZE - 1))
39#define LPAGE_MASK (~(LPAGE_SIZE - 1))
40#define SPAGE_MASK (~(SPAGE_SIZE - 1))
41
42#define lv1ent_fault(sent) ((*(sent) == ZERO_LV2LINK) || \
43			   ((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
44#define lv1ent_zero(sent) (*(sent) == ZERO_LV2LINK)
45#define lv1ent_page_zero(sent) ((*(sent) & 3) == 1)
46#define lv1ent_page(sent) ((*(sent) != ZERO_LV2LINK) && \
47			  ((*(sent) & 3) == 1))
48#define lv1ent_section(sent) ((*(sent) & 3) == 2)
49
50#define lv2ent_fault(pent) ((*(pent) & 3) == 0)
51#define lv2ent_small(pent) ((*(pent) & 2) == 2)
52#define lv2ent_large(pent) ((*(pent) & 3) == 1)
53
54/*
55 * v1.x - v3.x SYSMMU supports 32bit physical and 32bit virtual address spaces
56 * v5.0 introduced support for 36bit physical address space by shifting
57 * all page entry values by 4 bits.
58 * All SYSMMU controllers in the system support the address spaces of the same
59 * size, so PG_ENT_SHIFT can be initialized on first SYSMMU probe to proper
60 * value (0 or 4).
61 */
62static short PG_ENT_SHIFT = -1;
63#define SYSMMU_PG_ENT_SHIFT 0
64#define SYSMMU_V5_PG_ENT_SHIFT 4
65
66static const sysmmu_pte_t *LV1_PROT;
67static const sysmmu_pte_t SYSMMU_LV1_PROT[] = {
68	((0 << 15) | (0 << 10)), /* no access */
69	((1 << 15) | (1 << 10)), /* IOMMU_READ only */
70	((0 << 15) | (1 << 10)), /* IOMMU_WRITE not supported, use read/write */
71	((0 << 15) | (1 << 10)), /* IOMMU_READ | IOMMU_WRITE */
72};
73static const sysmmu_pte_t SYSMMU_V5_LV1_PROT[] = {
74	(0 << 4), /* no access */
75	(1 << 4), /* IOMMU_READ only */
76	(2 << 4), /* IOMMU_WRITE only */
77	(3 << 4), /* IOMMU_READ | IOMMU_WRITE */
78};
79
80static const sysmmu_pte_t *LV2_PROT;
81static const sysmmu_pte_t SYSMMU_LV2_PROT[] = {
82	((0 << 9) | (0 << 4)), /* no access */
83	((1 << 9) | (1 << 4)), /* IOMMU_READ only */
84	((0 << 9) | (1 << 4)), /* IOMMU_WRITE not supported, use read/write */
85	((0 << 9) | (1 << 4)), /* IOMMU_READ | IOMMU_WRITE */
86};
87static const sysmmu_pte_t SYSMMU_V5_LV2_PROT[] = {
88	(0 << 2), /* no access */
89	(1 << 2), /* IOMMU_READ only */
90	(2 << 2), /* IOMMU_WRITE only */
91	(3 << 2), /* IOMMU_READ | IOMMU_WRITE */
92};
93
94#define SYSMMU_SUPPORTED_PROT_BITS (IOMMU_READ | IOMMU_WRITE)
95
96#define sect_to_phys(ent) (((phys_addr_t) ent) << PG_ENT_SHIFT)
97#define section_phys(sent) (sect_to_phys(*(sent)) & SECT_MASK)
98#define section_offs(iova) (iova & (SECT_SIZE - 1))
99#define lpage_phys(pent) (sect_to_phys(*(pent)) & LPAGE_MASK)
100#define lpage_offs(iova) (iova & (LPAGE_SIZE - 1))
101#define spage_phys(pent) (sect_to_phys(*(pent)) & SPAGE_MASK)
102#define spage_offs(iova) (iova & (SPAGE_SIZE - 1))
103
104#define NUM_LV1ENTRIES 4096
105#define NUM_LV2ENTRIES (SECT_SIZE / SPAGE_SIZE)
106
107static u32 lv1ent_offset(sysmmu_iova_t iova)
108{
109	return iova >> SECT_ORDER;
110}
111
112static u32 lv2ent_offset(sysmmu_iova_t iova)
113{
114	return (iova >> SPAGE_ORDER) & (NUM_LV2ENTRIES - 1);
115}
116
117#define LV1TABLE_SIZE (NUM_LV1ENTRIES * sizeof(sysmmu_pte_t))
118#define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(sysmmu_pte_t))
119
120#define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
121#define lv2table_base(sent) (sect_to_phys(*(sent) & 0xFFFFFFC0))
122
123#define mk_lv1ent_sect(pa, prot) ((pa >> PG_ENT_SHIFT) | LV1_PROT[prot] | 2)
124#define mk_lv1ent_page(pa) ((pa >> PG_ENT_SHIFT) | 1)
125#define mk_lv2ent_lpage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 1)
126#define mk_lv2ent_spage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 2)
127
128#define CTRL_ENABLE	0x5
129#define CTRL_BLOCK	0x7
130#define CTRL_DISABLE	0x0
131
132#define CFG_LRU		0x1
133#define CFG_EAP		(1 << 2)
134#define CFG_QOS(n)	((n & 0xF) << 7)
135#define CFG_ACGEN	(1 << 24) /* System MMU 3.3 only */
136#define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
137#define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */
138
139#define CTRL_VM_ENABLE			BIT(0)
140#define CTRL_VM_FAULT_MODE_STALL	BIT(3)
141#define CAPA0_CAPA1_EXIST		BIT(11)
142#define CAPA1_VCR_ENABLED		BIT(14)
143
144/* common registers */
145#define REG_MMU_CTRL		0x000
146#define REG_MMU_CFG		0x004
147#define REG_MMU_STATUS		0x008
148#define REG_MMU_VERSION		0x034
149
150#define MMU_MAJ_VER(val)	((val) >> 7)
151#define MMU_MIN_VER(val)	((val) & 0x7F)
152#define MMU_RAW_VER(reg)	(((reg) >> 21) & ((1 << 11) - 1)) /* 11 bits */
153
154#define MAKE_MMU_VER(maj, min)	((((maj) & 0xF) << 7) | ((min) & 0x7F))
155
156/* v1.x - v3.x registers */
157#define REG_PAGE_FAULT_ADDR	0x024
158#define REG_AW_FAULT_ADDR	0x028
159#define REG_AR_FAULT_ADDR	0x02C
160#define REG_DEFAULT_SLAVE_ADDR	0x030
161
162/* v5.x registers */
163#define REG_V5_FAULT_AR_VA	0x070
164#define REG_V5_FAULT_AW_VA	0x080
165
166/* v7.x registers */
167#define REG_V7_CAPA0		0x870
168#define REG_V7_CAPA1		0x874
169#define REG_V7_CTRL_VM		0x8000
170
171#define has_sysmmu(dev)		(dev_iommu_priv_get(dev) != NULL)
172
173static struct device *dma_dev;
174static struct kmem_cache *lv2table_kmem_cache;
175static sysmmu_pte_t *zero_lv2_table;
176#define ZERO_LV2LINK mk_lv1ent_page(virt_to_phys(zero_lv2_table))
177
178static sysmmu_pte_t *section_entry(sysmmu_pte_t *pgtable, sysmmu_iova_t iova)
179{
180	return pgtable + lv1ent_offset(iova);
181}
182
183static sysmmu_pte_t *page_entry(sysmmu_pte_t *sent, sysmmu_iova_t iova)
184{
185	return (sysmmu_pte_t *)phys_to_virt(
186				lv2table_base(sent)) + lv2ent_offset(iova);
187}
188
189struct sysmmu_fault {
190	sysmmu_iova_t addr;	/* IOVA address that caused fault */
191	const char *name;	/* human readable fault name */
192	unsigned int type;	/* fault type for report_iommu_fault() */
193};
194
195struct sysmmu_v1_fault_info {
196	unsigned short addr_reg; /* register to read IOVA fault address */
197	const char *name;	/* human readable fault name */
198	unsigned int type;	/* fault type for report_iommu_fault */
199};
200
201static const struct sysmmu_v1_fault_info sysmmu_v1_faults[] = {
202	{ REG_PAGE_FAULT_ADDR, "PAGE", IOMMU_FAULT_READ },
203	{ REG_AR_FAULT_ADDR, "MULTI-HIT", IOMMU_FAULT_READ },
204	{ REG_AW_FAULT_ADDR, "MULTI-HIT", IOMMU_FAULT_WRITE },
205	{ REG_DEFAULT_SLAVE_ADDR, "BUS ERROR", IOMMU_FAULT_READ },
206	{ REG_AR_FAULT_ADDR, "SECURITY PROTECTION", IOMMU_FAULT_READ },
207	{ REG_AR_FAULT_ADDR, "ACCESS PROTECTION", IOMMU_FAULT_READ },
208	{ REG_AW_FAULT_ADDR, "SECURITY PROTECTION", IOMMU_FAULT_WRITE },
209	{ REG_AW_FAULT_ADDR, "ACCESS PROTECTION", IOMMU_FAULT_WRITE },
210};
211
212/* SysMMU v5 has the same faults for AR (0..4 bits) and AW (16..20 bits) */
213static const char * const sysmmu_v5_fault_names[] = {
214	"PTW",
215	"PAGE",
216	"MULTI-HIT",
217	"ACCESS PROTECTION",
218	"SECURITY PROTECTION"
219};
220
221static const char * const sysmmu_v7_fault_names[] = {
222	"PTW",
223	"PAGE",
224	"ACCESS PROTECTION",
225	"RESERVED"
226};
227
228/*
229 * This structure is attached to dev->iommu->priv of the master device
230 * on device add, contains a list of SYSMMU controllers defined by device tree,
231 * which are bound to given master device. It is usually referenced by 'owner'
232 * pointer.
233*/
234struct exynos_iommu_owner {
235	struct list_head controllers;	/* list of sysmmu_drvdata.owner_node */
236	struct iommu_domain *domain;	/* domain this device is attached */
237	struct mutex rpm_lock;		/* for runtime pm of all sysmmus */
238};
239
240/*
241 * This structure exynos specific generalization of struct iommu_domain.
242 * It contains list of SYSMMU controllers from all master devices, which has
243 * been attached to this domain and page tables of IO address space defined by
244 * it. It is usually referenced by 'domain' pointer.
245 */
246struct exynos_iommu_domain {
247	struct list_head clients; /* list of sysmmu_drvdata.domain_node */
248	sysmmu_pte_t *pgtable;	/* lv1 page table, 16KB */
249	short *lv2entcnt;	/* free lv2 entry counter for each section */
250	spinlock_t lock;	/* lock for modyfying list of clients */
251	spinlock_t pgtablelock;	/* lock for modifying page table @ pgtable */
252	struct iommu_domain domain; /* generic domain data structure */
253};
254
255struct sysmmu_drvdata;
256
257/*
258 * SysMMU version specific data. Contains offsets for the registers which can
259 * be found in different SysMMU variants, but have different offset values.
260 * Also contains version specific callbacks to abstract the hardware.
261 */
262struct sysmmu_variant {
263	u32 pt_base;		/* page table base address (physical) */
264	u32 flush_all;		/* invalidate all TLB entries */
265	u32 flush_entry;	/* invalidate specific TLB entry */
266	u32 flush_range;	/* invalidate TLB entries in specified range */
267	u32 flush_start;	/* start address of range invalidation */
268	u32 flush_end;		/* end address of range invalidation */
269	u32 int_status;		/* interrupt status information */
270	u32 int_clear;		/* clear the interrupt */
271	u32 fault_va;		/* IOVA address that caused fault */
272	u32 fault_info;		/* fault transaction info */
273
274	int (*get_fault_info)(struct sysmmu_drvdata *data, unsigned int itype,
275			      struct sysmmu_fault *fault);
276};
277
278/*
279 * This structure hold all data of a single SYSMMU controller, this includes
280 * hw resources like registers and clocks, pointers and list nodes to connect
281 * it to all other structures, internal state and parameters read from device
282 * tree. It is usually referenced by 'data' pointer.
283 */
284struct sysmmu_drvdata {
285	struct device *sysmmu;		/* SYSMMU controller device */
286	struct device *master;		/* master device (owner) */
287	struct device_link *link;	/* runtime PM link to master */
288	void __iomem *sfrbase;		/* our registers */
289	struct clk *clk;		/* SYSMMU's clock */
290	struct clk *aclk;		/* SYSMMU's aclk clock */
291	struct clk *pclk;		/* SYSMMU's pclk clock */
292	struct clk *clk_master;		/* master's device clock */
293	spinlock_t lock;		/* lock for modyfying state */
294	bool active;			/* current status */
295	struct exynos_iommu_domain *domain; /* domain we belong to */
296	struct list_head domain_node;	/* node for domain clients list */
297	struct list_head owner_node;	/* node for owner controllers list */
298	phys_addr_t pgtable;		/* assigned page table structure */
299	unsigned int version;		/* our version */
300
301	struct iommu_device iommu;	/* IOMMU core handle */
302	const struct sysmmu_variant *variant; /* version specific data */
303
304	/* v7 fields */
305	bool has_vcr;			/* virtual machine control register */
306};
307
308#define SYSMMU_REG(data, reg) ((data)->sfrbase + (data)->variant->reg)
309
310static int exynos_sysmmu_v1_get_fault_info(struct sysmmu_drvdata *data,
311					   unsigned int itype,
312					   struct sysmmu_fault *fault)
313{
314	const struct sysmmu_v1_fault_info *finfo;
315
316	if (itype >= ARRAY_SIZE(sysmmu_v1_faults))
317		return -ENXIO;
318
319	finfo = &sysmmu_v1_faults[itype];
320	fault->addr = readl(data->sfrbase + finfo->addr_reg);
321	fault->name = finfo->name;
322	fault->type = finfo->type;
323
324	return 0;
325}
326
327static int exynos_sysmmu_v5_get_fault_info(struct sysmmu_drvdata *data,
328					   unsigned int itype,
329					   struct sysmmu_fault *fault)
330{
331	unsigned int addr_reg;
332
333	if (itype < ARRAY_SIZE(sysmmu_v5_fault_names)) {
334		fault->type = IOMMU_FAULT_READ;
335		addr_reg = REG_V5_FAULT_AR_VA;
336	} else if (itype >= 16 && itype <= 20) {
337		fault->type = IOMMU_FAULT_WRITE;
338		addr_reg = REG_V5_FAULT_AW_VA;
339		itype -= 16;
340	} else {
341		return -ENXIO;
342	}
343
344	fault->name = sysmmu_v5_fault_names[itype];
345	fault->addr = readl(data->sfrbase + addr_reg);
346
347	return 0;
348}
349
350static int exynos_sysmmu_v7_get_fault_info(struct sysmmu_drvdata *data,
351					   unsigned int itype,
352					   struct sysmmu_fault *fault)
353{
354	u32 info = readl(SYSMMU_REG(data, fault_info));
355
356	fault->addr = readl(SYSMMU_REG(data, fault_va));
357	fault->name = sysmmu_v7_fault_names[itype % 4];
358	fault->type = (info & BIT(20)) ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ;
359
360	return 0;
361}
362
363/* SysMMU v1..v3 */
364static const struct sysmmu_variant sysmmu_v1_variant = {
365	.flush_all	= 0x0c,
366	.flush_entry	= 0x10,
367	.pt_base	= 0x14,
368	.int_status	= 0x18,
369	.int_clear	= 0x1c,
370
371	.get_fault_info	= exynos_sysmmu_v1_get_fault_info,
372};
373
374/* SysMMU v5 */
375static const struct sysmmu_variant sysmmu_v5_variant = {
376	.pt_base	= 0x0c,
377	.flush_all	= 0x10,
378	.flush_entry	= 0x14,
379	.flush_range	= 0x18,
380	.flush_start	= 0x20,
381	.flush_end	= 0x24,
382	.int_status	= 0x60,
383	.int_clear	= 0x64,
384
385	.get_fault_info	= exynos_sysmmu_v5_get_fault_info,
386};
387
388/* SysMMU v7: non-VM capable register layout */
389static const struct sysmmu_variant sysmmu_v7_variant = {
390	.pt_base	= 0x0c,
391	.flush_all	= 0x10,
392	.flush_entry	= 0x14,
393	.flush_range	= 0x18,
394	.flush_start	= 0x20,
395	.flush_end	= 0x24,
396	.int_status	= 0x60,
397	.int_clear	= 0x64,
398	.fault_va	= 0x70,
399	.fault_info	= 0x78,
400
401	.get_fault_info	= exynos_sysmmu_v7_get_fault_info,
402};
403
404/* SysMMU v7: VM capable register layout */
405static const struct sysmmu_variant sysmmu_v7_vm_variant = {
406	.pt_base	= 0x800c,
407	.flush_all	= 0x8010,
408	.flush_entry	= 0x8014,
409	.flush_range	= 0x8018,
410	.flush_start	= 0x8020,
411	.flush_end	= 0x8024,
412	.int_status	= 0x60,
413	.int_clear	= 0x64,
414	.fault_va	= 0x1000,
415	.fault_info	= 0x1004,
416
417	.get_fault_info	= exynos_sysmmu_v7_get_fault_info,
418};
419
420static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
421{
422	return container_of(dom, struct exynos_iommu_domain, domain);
423}
424
425static void sysmmu_unblock(struct sysmmu_drvdata *data)
426{
427	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
428}
429
430static bool sysmmu_block(struct sysmmu_drvdata *data)
431{
432	int i = 120;
433
434	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
435	while ((i > 0) && !(readl(data->sfrbase + REG_MMU_STATUS) & 1))
436		--i;
437
438	if (!(readl(data->sfrbase + REG_MMU_STATUS) & 1)) {
439		sysmmu_unblock(data);
440		return false;
441	}
442
443	return true;
444}
445
446static void __sysmmu_tlb_invalidate(struct sysmmu_drvdata *data)
447{
448	writel(0x1, SYSMMU_REG(data, flush_all));
449}
450
451static void __sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
452				sysmmu_iova_t iova, unsigned int num_inv)
453{
454	unsigned int i;
455
456	if (MMU_MAJ_VER(data->version) < 5 || num_inv == 1) {
457		for (i = 0; i < num_inv; i++) {
458			writel((iova & SPAGE_MASK) | 1,
459			       SYSMMU_REG(data, flush_entry));
460			iova += SPAGE_SIZE;
461		}
462	} else {
463		writel(iova & SPAGE_MASK, SYSMMU_REG(data, flush_start));
464		writel((iova & SPAGE_MASK) + (num_inv - 1) * SPAGE_SIZE,
465		       SYSMMU_REG(data, flush_end));
466		writel(0x1, SYSMMU_REG(data, flush_range));
467	}
468}
469
470static void __sysmmu_set_ptbase(struct sysmmu_drvdata *data, phys_addr_t pgd)
471{
472	u32 pt_base;
473
474	if (MMU_MAJ_VER(data->version) < 5)
475		pt_base = pgd;
476	else
477		pt_base = pgd >> SPAGE_ORDER;
478
479	writel(pt_base, SYSMMU_REG(data, pt_base));
480	__sysmmu_tlb_invalidate(data);
481}
482
483static void __sysmmu_enable_clocks(struct sysmmu_drvdata *data)
484{
485	BUG_ON(clk_prepare_enable(data->clk_master));
486	BUG_ON(clk_prepare_enable(data->clk));
487	BUG_ON(clk_prepare_enable(data->pclk));
488	BUG_ON(clk_prepare_enable(data->aclk));
489}
490
491static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
492{
493	clk_disable_unprepare(data->aclk);
494	clk_disable_unprepare(data->pclk);
495	clk_disable_unprepare(data->clk);
496	clk_disable_unprepare(data->clk_master);
497}
498
499static bool __sysmmu_has_capa1(struct sysmmu_drvdata *data)
500{
501	u32 capa0 = readl(data->sfrbase + REG_V7_CAPA0);
502
503	return capa0 & CAPA0_CAPA1_EXIST;
504}
505
506static void __sysmmu_get_vcr(struct sysmmu_drvdata *data)
507{
508	u32 capa1 = readl(data->sfrbase + REG_V7_CAPA1);
509
510	data->has_vcr = capa1 & CAPA1_VCR_ENABLED;
511}
512
513static void __sysmmu_get_version(struct sysmmu_drvdata *data)
514{
515	u32 ver;
516
517	__sysmmu_enable_clocks(data);
518
519	ver = readl(data->sfrbase + REG_MMU_VERSION);
520
521	/* controllers on some SoCs don't report proper version */
522	if (ver == 0x80000001u)
523		data->version = MAKE_MMU_VER(1, 0);
524	else
525		data->version = MMU_RAW_VER(ver);
526
527	dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
528		MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
529
530	if (MMU_MAJ_VER(data->version) < 5) {
531		data->variant = &sysmmu_v1_variant;
532	} else if (MMU_MAJ_VER(data->version) < 7) {
533		data->variant = &sysmmu_v5_variant;
534	} else {
535		if (__sysmmu_has_capa1(data))
536			__sysmmu_get_vcr(data);
537		if (data->has_vcr)
538			data->variant = &sysmmu_v7_vm_variant;
539		else
540			data->variant = &sysmmu_v7_variant;
541	}
542
543	__sysmmu_disable_clocks(data);
544}
545
546static void show_fault_information(struct sysmmu_drvdata *data,
547				   const struct sysmmu_fault *fault)
548{
549	sysmmu_pte_t *ent;
550
551	dev_err(data->sysmmu, "%s: [%s] %s FAULT occurred at %#x\n",
552		dev_name(data->master),
553		fault->type == IOMMU_FAULT_READ ? "READ" : "WRITE",
554		fault->name, fault->addr);
555	dev_dbg(data->sysmmu, "Page table base: %pa\n", &data->pgtable);
556	ent = section_entry(phys_to_virt(data->pgtable), fault->addr);
557	dev_dbg(data->sysmmu, "\tLv1 entry: %#x\n", *ent);
558	if (lv1ent_page(ent)) {
559		ent = page_entry(ent, fault->addr);
560		dev_dbg(data->sysmmu, "\t Lv2 entry: %#x\n", *ent);
561	}
562}
563
564static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
565{
566	struct sysmmu_drvdata *data = dev_id;
567	unsigned int itype;
568	struct sysmmu_fault fault;
569	int ret = -ENOSYS;
570
571	WARN_ON(!data->active);
572
573	spin_lock(&data->lock);
574	clk_enable(data->clk_master);
575
576	itype = __ffs(readl(SYSMMU_REG(data, int_status)));
577	ret = data->variant->get_fault_info(data, itype, &fault);
578	if (ret) {
579		dev_err(data->sysmmu, "Unhandled interrupt bit %u\n", itype);
580		goto out;
581	}
582	show_fault_information(data, &fault);
583
584	if (data->domain) {
585		ret = report_iommu_fault(&data->domain->domain, data->master,
586					 fault.addr, fault.type);
587	}
588	if (ret)
589		panic("Unrecoverable System MMU Fault!");
590
591out:
592	writel(1 << itype, SYSMMU_REG(data, int_clear));
593
594	/* SysMMU is in blocked state when interrupt occurred */
595	sysmmu_unblock(data);
596	clk_disable(data->clk_master);
597	spin_unlock(&data->lock);
598
599	return IRQ_HANDLED;
600}
601
602static void __sysmmu_disable(struct sysmmu_drvdata *data)
603{
604	unsigned long flags;
605
606	clk_enable(data->clk_master);
607
608	spin_lock_irqsave(&data->lock, flags);
609	writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
610	writel(0, data->sfrbase + REG_MMU_CFG);
611	data->active = false;
612	spin_unlock_irqrestore(&data->lock, flags);
613
614	__sysmmu_disable_clocks(data);
615}
616
617static void __sysmmu_init_config(struct sysmmu_drvdata *data)
618{
619	unsigned int cfg;
620
621	if (data->version <= MAKE_MMU_VER(3, 1))
622		cfg = CFG_LRU | CFG_QOS(15);
623	else if (data->version <= MAKE_MMU_VER(3, 2))
624		cfg = CFG_LRU | CFG_QOS(15) | CFG_FLPDCACHE | CFG_SYSSEL;
625	else
626		cfg = CFG_QOS(15) | CFG_FLPDCACHE | CFG_ACGEN;
627
628	cfg |= CFG_EAP; /* enable access protection bits check */
629
630	writel(cfg, data->sfrbase + REG_MMU_CFG);
631}
632
633static void __sysmmu_enable_vid(struct sysmmu_drvdata *data)
634{
635	u32 ctrl;
636
637	if (MMU_MAJ_VER(data->version) < 7 || !data->has_vcr)
638		return;
639
640	ctrl = readl(data->sfrbase + REG_V7_CTRL_VM);
641	ctrl |= CTRL_VM_ENABLE | CTRL_VM_FAULT_MODE_STALL;
642	writel(ctrl, data->sfrbase + REG_V7_CTRL_VM);
643}
644
645static void __sysmmu_enable(struct sysmmu_drvdata *data)
646{
647	unsigned long flags;
648
649	__sysmmu_enable_clocks(data);
650
651	spin_lock_irqsave(&data->lock, flags);
652	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
653	__sysmmu_init_config(data);
654	__sysmmu_set_ptbase(data, data->pgtable);
655	__sysmmu_enable_vid(data);
656	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
657	data->active = true;
658	spin_unlock_irqrestore(&data->lock, flags);
659
660	/*
661	 * SYSMMU driver keeps master's clock enabled only for the short
662	 * time, while accessing the registers. For performing address
663	 * translation during DMA transaction it relies on the client
664	 * driver to enable it.
665	 */
666	clk_disable(data->clk_master);
667}
668
669static void sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata *data,
670					    sysmmu_iova_t iova)
671{
672	unsigned long flags;
673
674	spin_lock_irqsave(&data->lock, flags);
675	if (data->active && data->version >= MAKE_MMU_VER(3, 3)) {
676		clk_enable(data->clk_master);
677		if (sysmmu_block(data)) {
678			if (data->version >= MAKE_MMU_VER(5, 0))
679				__sysmmu_tlb_invalidate(data);
680			else
681				__sysmmu_tlb_invalidate_entry(data, iova, 1);
682			sysmmu_unblock(data);
683		}
684		clk_disable(data->clk_master);
685	}
686	spin_unlock_irqrestore(&data->lock, flags);
687}
688
689static void sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
690					sysmmu_iova_t iova, size_t size)
691{
692	unsigned long flags;
693
694	spin_lock_irqsave(&data->lock, flags);
695	if (data->active) {
696		unsigned int num_inv = 1;
697
698		clk_enable(data->clk_master);
699
700		/*
701		 * L2TLB invalidation required
702		 * 4KB page: 1 invalidation
703		 * 64KB page: 16 invalidations
704		 * 1MB page: 64 invalidations
705		 * because it is set-associative TLB
706		 * with 8-way and 64 sets.
707		 * 1MB page can be cached in one of all sets.
708		 * 64KB page can be one of 16 consecutive sets.
709		 */
710		if (MMU_MAJ_VER(data->version) == 2)
711			num_inv = min_t(unsigned int, size / SPAGE_SIZE, 64);
712
713		if (sysmmu_block(data)) {
714			__sysmmu_tlb_invalidate_entry(data, iova, num_inv);
715			sysmmu_unblock(data);
716		}
717		clk_disable(data->clk_master);
718	}
719	spin_unlock_irqrestore(&data->lock, flags);
720}
721
722static const struct iommu_ops exynos_iommu_ops;
723
724static int exynos_sysmmu_probe(struct platform_device *pdev)
725{
726	int irq, ret;
727	struct device *dev = &pdev->dev;
728	struct sysmmu_drvdata *data;
729	struct resource *res;
730
731	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
732	if (!data)
733		return -ENOMEM;
734
735	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
736	data->sfrbase = devm_ioremap_resource(dev, res);
737	if (IS_ERR(data->sfrbase))
738		return PTR_ERR(data->sfrbase);
739
740	irq = platform_get_irq(pdev, 0);
741	if (irq <= 0)
742		return irq;
743
744	ret = devm_request_irq(dev, irq, exynos_sysmmu_irq, 0,
745				dev_name(dev), data);
746	if (ret) {
747		dev_err(dev, "Unabled to register handler of irq %d\n", irq);
748		return ret;
749	}
750
751	data->clk = devm_clk_get_optional(dev, "sysmmu");
752	if (IS_ERR(data->clk))
753		return PTR_ERR(data->clk);
754
755	data->aclk = devm_clk_get_optional(dev, "aclk");
756	if (IS_ERR(data->aclk))
757		return PTR_ERR(data->aclk);
758
759	data->pclk = devm_clk_get_optional(dev, "pclk");
760	if (IS_ERR(data->pclk))
761		return PTR_ERR(data->pclk);
762
763	if (!data->clk && (!data->aclk || !data->pclk)) {
764		dev_err(dev, "Failed to get device clock(s)!\n");
765		return -ENOSYS;
766	}
767
768	data->clk_master = devm_clk_get_optional(dev, "master");
769	if (IS_ERR(data->clk_master))
770		return PTR_ERR(data->clk_master);
771
772	data->sysmmu = dev;
773	spin_lock_init(&data->lock);
774
775	__sysmmu_get_version(data);
776
777	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
778				     dev_name(data->sysmmu));
779	if (ret)
780		return ret;
781
782	platform_set_drvdata(pdev, data);
783
784	if (PG_ENT_SHIFT < 0) {
785		if (MMU_MAJ_VER(data->version) < 5) {
786			PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;
787			LV1_PROT = SYSMMU_LV1_PROT;
788			LV2_PROT = SYSMMU_LV2_PROT;
789		} else {
790			PG_ENT_SHIFT = SYSMMU_V5_PG_ENT_SHIFT;
791			LV1_PROT = SYSMMU_V5_LV1_PROT;
792			LV2_PROT = SYSMMU_V5_LV2_PROT;
793		}
794	}
795
796	if (MMU_MAJ_VER(data->version) >= 5) {
797		ret = dma_set_mask(dev, DMA_BIT_MASK(36));
798		if (ret) {
799			dev_err(dev, "Unable to set DMA mask: %d\n", ret);
800			goto err_dma_set_mask;
801		}
802	}
803
804	/*
805	 * use the first registered sysmmu device for performing
806	 * dma mapping operations on iommu page tables (cpu cache flush)
807	 */
808	if (!dma_dev)
809		dma_dev = &pdev->dev;
810
811	pm_runtime_enable(dev);
812
813	ret = iommu_device_register(&data->iommu, &exynos_iommu_ops, dev);
814	if (ret)
815		goto err_dma_set_mask;
816
817	return 0;
818
819err_dma_set_mask:
820	iommu_device_sysfs_remove(&data->iommu);
821	return ret;
822}
823
824static int __maybe_unused exynos_sysmmu_suspend(struct device *dev)
825{
826	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
827	struct device *master = data->master;
828
829	if (master) {
830		struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
831
832		mutex_lock(&owner->rpm_lock);
833		if (&data->domain->domain != &exynos_identity_domain) {
834			dev_dbg(data->sysmmu, "saving state\n");
835			__sysmmu_disable(data);
836		}
837		mutex_unlock(&owner->rpm_lock);
838	}
839	return 0;
840}
841
842static int __maybe_unused exynos_sysmmu_resume(struct device *dev)
843{
844	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
845	struct device *master = data->master;
846
847	if (master) {
848		struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
849
850		mutex_lock(&owner->rpm_lock);
851		if (&data->domain->domain != &exynos_identity_domain) {
852			dev_dbg(data->sysmmu, "restoring state\n");
853			__sysmmu_enable(data);
854		}
855		mutex_unlock(&owner->rpm_lock);
856	}
857	return 0;
858}
859
860static const struct dev_pm_ops sysmmu_pm_ops = {
861	SET_RUNTIME_PM_OPS(exynos_sysmmu_suspend, exynos_sysmmu_resume, NULL)
862	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
863				pm_runtime_force_resume)
864};
865
866static const struct of_device_id sysmmu_of_match[] = {
867	{ .compatible	= "samsung,exynos-sysmmu", },
868	{ },
869};
870
871static struct platform_driver exynos_sysmmu_driver __refdata = {
872	.probe	= exynos_sysmmu_probe,
873	.driver	= {
874		.name		= "exynos-sysmmu",
875		.of_match_table	= sysmmu_of_match,
876		.pm		= &sysmmu_pm_ops,
877		.suppress_bind_attrs = true,
878	}
879};
880
881static inline void exynos_iommu_set_pte(sysmmu_pte_t *ent, sysmmu_pte_t val)
882{
883	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent), sizeof(*ent),
884				DMA_TO_DEVICE);
885	*ent = cpu_to_le32(val);
886	dma_sync_single_for_device(dma_dev, virt_to_phys(ent), sizeof(*ent),
887				   DMA_TO_DEVICE);
888}
889
890static struct iommu_domain *exynos_iommu_domain_alloc_paging(struct device *dev)
891{
892	struct exynos_iommu_domain *domain;
893	dma_addr_t handle;
894	int i;
895
896	/* Check if correct PTE offsets are initialized */
897	BUG_ON(PG_ENT_SHIFT < 0 || !dma_dev);
898
899	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
900	if (!domain)
901		return NULL;
902
903	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
904	if (!domain->pgtable)
905		goto err_pgtable;
906
907	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
908	if (!domain->lv2entcnt)
909		goto err_counter;
910
911	/* Workaround for System MMU v3.3 to prevent caching 1MiB mapping */
912	for (i = 0; i < NUM_LV1ENTRIES; i++)
913		domain->pgtable[i] = ZERO_LV2LINK;
914
915	handle = dma_map_single(dma_dev, domain->pgtable, LV1TABLE_SIZE,
916				DMA_TO_DEVICE);
917	/* For mapping page table entries we rely on dma == phys */
918	BUG_ON(handle != virt_to_phys(domain->pgtable));
919	if (dma_mapping_error(dma_dev, handle))
920		goto err_lv2ent;
921
922	spin_lock_init(&domain->lock);
923	spin_lock_init(&domain->pgtablelock);
924	INIT_LIST_HEAD(&domain->clients);
925
926	domain->domain.geometry.aperture_start = 0;
927	domain->domain.geometry.aperture_end   = ~0UL;
928	domain->domain.geometry.force_aperture = true;
929
930	return &domain->domain;
931
932err_lv2ent:
933	free_pages((unsigned long)domain->lv2entcnt, 1);
934err_counter:
935	free_pages((unsigned long)domain->pgtable, 2);
936err_pgtable:
937	kfree(domain);
938	return NULL;
939}
940
941static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
942{
943	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
944	struct sysmmu_drvdata *data, *next;
945	unsigned long flags;
946	int i;
947
948	WARN_ON(!list_empty(&domain->clients));
949
950	spin_lock_irqsave(&domain->lock, flags);
951
952	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
953		spin_lock(&data->lock);
954		__sysmmu_disable(data);
955		data->pgtable = 0;
956		data->domain = NULL;
957		list_del_init(&data->domain_node);
958		spin_unlock(&data->lock);
959	}
960
961	spin_unlock_irqrestore(&domain->lock, flags);
962
963	dma_unmap_single(dma_dev, virt_to_phys(domain->pgtable), LV1TABLE_SIZE,
964			 DMA_TO_DEVICE);
965
966	for (i = 0; i < NUM_LV1ENTRIES; i++)
967		if (lv1ent_page(domain->pgtable + i)) {
968			phys_addr_t base = lv2table_base(domain->pgtable + i);
969
970			dma_unmap_single(dma_dev, base, LV2TABLE_SIZE,
971					 DMA_TO_DEVICE);
972			kmem_cache_free(lv2table_kmem_cache,
973					phys_to_virt(base));
974		}
975
976	free_pages((unsigned long)domain->pgtable, 2);
977	free_pages((unsigned long)domain->lv2entcnt, 1);
978	kfree(domain);
979}
980
981static int exynos_iommu_identity_attach(struct iommu_domain *identity_domain,
982					struct device *dev)
983{
984	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
985	struct exynos_iommu_domain *domain;
986	phys_addr_t pagetable;
987	struct sysmmu_drvdata *data, *next;
988	unsigned long flags;
989
990	if (owner->domain == identity_domain)
991		return 0;
992
993	domain = to_exynos_domain(owner->domain);
994	pagetable = virt_to_phys(domain->pgtable);
995
996	mutex_lock(&owner->rpm_lock);
997
998	list_for_each_entry(data, &owner->controllers, owner_node) {
999		pm_runtime_get_noresume(data->sysmmu);
1000		if (pm_runtime_active(data->sysmmu))
1001			__sysmmu_disable(data);
1002		pm_runtime_put(data->sysmmu);
1003	}
1004
1005	spin_lock_irqsave(&domain->lock, flags);
1006	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
1007		spin_lock(&data->lock);
1008		data->pgtable = 0;
1009		data->domain = NULL;
1010		list_del_init(&data->domain_node);
1011		spin_unlock(&data->lock);
1012	}
1013	owner->domain = identity_domain;
1014	spin_unlock_irqrestore(&domain->lock, flags);
1015
1016	mutex_unlock(&owner->rpm_lock);
1017
1018	dev_dbg(dev, "%s: Restored IOMMU to IDENTITY from pgtable %pa\n",
1019		__func__, &pagetable);
1020	return 0;
1021}
1022
1023static struct iommu_domain_ops exynos_identity_ops = {
1024	.attach_dev = exynos_iommu_identity_attach,
1025};
1026
1027static struct iommu_domain exynos_identity_domain = {
1028	.type = IOMMU_DOMAIN_IDENTITY,
1029	.ops = &exynos_identity_ops,
1030};
1031
1032static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain,
1033				   struct device *dev)
1034{
1035	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1036	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1037	struct sysmmu_drvdata *data;
1038	phys_addr_t pagetable = virt_to_phys(domain->pgtable);
1039	unsigned long flags;
1040	int err;
1041
1042	err = exynos_iommu_identity_attach(&exynos_identity_domain, dev);
1043	if (err)
1044		return err;
1045
1046	mutex_lock(&owner->rpm_lock);
1047
1048	spin_lock_irqsave(&domain->lock, flags);
1049	list_for_each_entry(data, &owner->controllers, owner_node) {
1050		spin_lock(&data->lock);
1051		data->pgtable = pagetable;
1052		data->domain = domain;
1053		list_add_tail(&data->domain_node, &domain->clients);
1054		spin_unlock(&data->lock);
1055	}
1056	owner->domain = iommu_domain;
1057	spin_unlock_irqrestore(&domain->lock, flags);
1058
1059	list_for_each_entry(data, &owner->controllers, owner_node) {
1060		pm_runtime_get_noresume(data->sysmmu);
1061		if (pm_runtime_active(data->sysmmu))
1062			__sysmmu_enable(data);
1063		pm_runtime_put(data->sysmmu);
1064	}
1065
1066	mutex_unlock(&owner->rpm_lock);
1067
1068	dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa\n", __func__,
1069		&pagetable);
1070
1071	return 0;
1072}
1073
1074static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
1075		sysmmu_pte_t *sent, sysmmu_iova_t iova, short *pgcounter)
1076{
1077	if (lv1ent_section(sent)) {
1078		WARN(1, "Trying mapping on %#08x mapped with 1MiB page", iova);
1079		return ERR_PTR(-EADDRINUSE);
1080	}
1081
1082	if (lv1ent_fault(sent)) {
1083		dma_addr_t handle;
1084		sysmmu_pte_t *pent;
1085		bool need_flush_flpd_cache = lv1ent_zero(sent);
1086
1087		pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
1088		BUG_ON((uintptr_t)pent & (LV2TABLE_SIZE - 1));
1089		if (!pent)
1090			return ERR_PTR(-ENOMEM);
1091
1092		exynos_iommu_set_pte(sent, mk_lv1ent_page(virt_to_phys(pent)));
1093		kmemleak_ignore(pent);
1094		*pgcounter = NUM_LV2ENTRIES;
1095		handle = dma_map_single(dma_dev, pent, LV2TABLE_SIZE,
1096					DMA_TO_DEVICE);
1097		if (dma_mapping_error(dma_dev, handle)) {
1098			kmem_cache_free(lv2table_kmem_cache, pent);
1099			return ERR_PTR(-EADDRINUSE);
1100		}
1101
1102		/*
1103		 * If pre-fetched SLPD is a faulty SLPD in zero_l2_table,
1104		 * FLPD cache may cache the address of zero_l2_table. This
1105		 * function replaces the zero_l2_table with new L2 page table
1106		 * to write valid mappings.
1107		 * Accessing the valid area may cause page fault since FLPD
1108		 * cache may still cache zero_l2_table for the valid area
1109		 * instead of new L2 page table that has the mapping
1110		 * information of the valid area.
1111		 * Thus any replacement of zero_l2_table with other valid L2
1112		 * page table must involve FLPD cache invalidation for System
1113		 * MMU v3.3.
1114		 * FLPD cache invalidation is performed with TLB invalidation
1115		 * by VPN without blocking. It is safe to invalidate TLB without
1116		 * blocking because the target address of TLB invalidation is
1117		 * not currently mapped.
1118		 */
1119		if (need_flush_flpd_cache) {
1120			struct sysmmu_drvdata *data;
1121
1122			spin_lock(&domain->lock);
1123			list_for_each_entry(data, &domain->clients, domain_node)
1124				sysmmu_tlb_invalidate_flpdcache(data, iova);
1125			spin_unlock(&domain->lock);
1126		}
1127	}
1128
1129	return page_entry(sent, iova);
1130}
1131
1132static int lv1set_section(struct exynos_iommu_domain *domain,
1133			  sysmmu_pte_t *sent, sysmmu_iova_t iova,
1134			  phys_addr_t paddr, int prot, short *pgcnt)
1135{
1136	if (lv1ent_section(sent)) {
1137		WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
1138			iova);
1139		return -EADDRINUSE;
1140	}
1141
1142	if (lv1ent_page(sent)) {
1143		if (*pgcnt != NUM_LV2ENTRIES) {
1144			WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
1145				iova);
1146			return -EADDRINUSE;
1147		}
1148
1149		kmem_cache_free(lv2table_kmem_cache, page_entry(sent, 0));
1150		*pgcnt = 0;
1151	}
1152
1153	exynos_iommu_set_pte(sent, mk_lv1ent_sect(paddr, prot));
1154
1155	spin_lock(&domain->lock);
1156	if (lv1ent_page_zero(sent)) {
1157		struct sysmmu_drvdata *data;
1158		/*
1159		 * Flushing FLPD cache in System MMU v3.3 that may cache a FLPD
1160		 * entry by speculative prefetch of SLPD which has no mapping.
1161		 */
1162		list_for_each_entry(data, &domain->clients, domain_node)
1163			sysmmu_tlb_invalidate_flpdcache(data, iova);
1164	}
1165	spin_unlock(&domain->lock);
1166
1167	return 0;
1168}
1169
1170static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
1171		       int prot, short *pgcnt)
1172{
1173	if (size == SPAGE_SIZE) {
1174		if (WARN_ON(!lv2ent_fault(pent)))
1175			return -EADDRINUSE;
1176
1177		exynos_iommu_set_pte(pent, mk_lv2ent_spage(paddr, prot));
1178		*pgcnt -= 1;
1179	} else { /* size == LPAGE_SIZE */
1180		int i;
1181		dma_addr_t pent_base = virt_to_phys(pent);
1182
1183		dma_sync_single_for_cpu(dma_dev, pent_base,
1184					sizeof(*pent) * SPAGES_PER_LPAGE,
1185					DMA_TO_DEVICE);
1186		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
1187			if (WARN_ON(!lv2ent_fault(pent))) {
1188				if (i > 0)
1189					memset(pent - i, 0, sizeof(*pent) * i);
1190				return -EADDRINUSE;
1191			}
1192
1193			*pent = mk_lv2ent_lpage(paddr, prot);
1194		}
1195		dma_sync_single_for_device(dma_dev, pent_base,
1196					   sizeof(*pent) * SPAGES_PER_LPAGE,
1197					   DMA_TO_DEVICE);
1198		*pgcnt -= SPAGES_PER_LPAGE;
1199	}
1200
1201	return 0;
1202}
1203
1204/*
1205 * *CAUTION* to the I/O virtual memory managers that support exynos-iommu:
1206 *
1207 * System MMU v3.x has advanced logic to improve address translation
1208 * performance with caching more page table entries by a page table walk.
1209 * However, the logic has a bug that while caching faulty page table entries,
1210 * System MMU reports page fault if the cached fault entry is hit even though
1211 * the fault entry is updated to a valid entry after the entry is cached.
1212 * To prevent caching faulty page table entries which may be updated to valid
1213 * entries later, the virtual memory manager should care about the workaround
1214 * for the problem. The following describes the workaround.
1215 *
1216 * Any two consecutive I/O virtual address regions must have a hole of 128KiB
1217 * at maximum to prevent misbehavior of System MMU 3.x (workaround for h/w bug).
1218 *
1219 * Precisely, any start address of I/O virtual region must be aligned with
1220 * the following sizes for System MMU v3.1 and v3.2.
1221 * System MMU v3.1: 128KiB
1222 * System MMU v3.2: 256KiB
1223 *
1224 * Because System MMU v3.3 caches page table entries more aggressively, it needs
1225 * more workarounds.
1226 * - Any two consecutive I/O virtual regions must have a hole of size larger
1227 *   than or equal to 128KiB.
1228 * - Start address of an I/O virtual region must be aligned by 128KiB.
1229 */
1230static int exynos_iommu_map(struct iommu_domain *iommu_domain,
1231			    unsigned long l_iova, phys_addr_t paddr, size_t size,
1232			    size_t count, int prot, gfp_t gfp, size_t *mapped)
1233{
1234	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1235	sysmmu_pte_t *entry;
1236	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
1237	unsigned long flags;
1238	int ret = -ENOMEM;
1239
1240	BUG_ON(domain->pgtable == NULL);
1241	prot &= SYSMMU_SUPPORTED_PROT_BITS;
1242
1243	spin_lock_irqsave(&domain->pgtablelock, flags);
1244
1245	entry = section_entry(domain->pgtable, iova);
1246
1247	if (size == SECT_SIZE) {
1248		ret = lv1set_section(domain, entry, iova, paddr, prot,
1249				     &domain->lv2entcnt[lv1ent_offset(iova)]);
1250	} else {
1251		sysmmu_pte_t *pent;
1252
1253		pent = alloc_lv2entry(domain, entry, iova,
1254				      &domain->lv2entcnt[lv1ent_offset(iova)]);
1255
1256		if (IS_ERR(pent))
1257			ret = PTR_ERR(pent);
1258		else
1259			ret = lv2set_page(pent, paddr, size, prot,
1260				       &domain->lv2entcnt[lv1ent_offset(iova)]);
1261	}
1262
1263	if (ret)
1264		pr_err("%s: Failed(%d) to map %#zx bytes @ %#x\n",
1265			__func__, ret, size, iova);
1266	else
1267		*mapped = size;
1268
1269	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1270
1271	return ret;
1272}
1273
1274static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *domain,
1275					      sysmmu_iova_t iova, size_t size)
1276{
1277	struct sysmmu_drvdata *data;
1278	unsigned long flags;
1279
1280	spin_lock_irqsave(&domain->lock, flags);
1281
1282	list_for_each_entry(data, &domain->clients, domain_node)
1283		sysmmu_tlb_invalidate_entry(data, iova, size);
1284
1285	spin_unlock_irqrestore(&domain->lock, flags);
1286}
1287
1288static size_t exynos_iommu_unmap(struct iommu_domain *iommu_domain,
1289				 unsigned long l_iova, size_t size, size_t count,
1290				 struct iommu_iotlb_gather *gather)
1291{
1292	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1293	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
1294	sysmmu_pte_t *ent;
1295	size_t err_pgsize;
1296	unsigned long flags;
1297
1298	BUG_ON(domain->pgtable == NULL);
1299
1300	spin_lock_irqsave(&domain->pgtablelock, flags);
1301
1302	ent = section_entry(domain->pgtable, iova);
1303
1304	if (lv1ent_section(ent)) {
1305		if (WARN_ON(size < SECT_SIZE)) {
1306			err_pgsize = SECT_SIZE;
1307			goto err;
1308		}
1309
1310		/* workaround for h/w bug in System MMU v3.3 */
1311		exynos_iommu_set_pte(ent, ZERO_LV2LINK);
1312		size = SECT_SIZE;
1313		goto done;
1314	}
1315
1316	if (unlikely(lv1ent_fault(ent))) {
1317		if (size > SECT_SIZE)
1318			size = SECT_SIZE;
1319		goto done;
1320	}
1321
1322	/* lv1ent_page(sent) == true here */
1323
1324	ent = page_entry(ent, iova);
1325
1326	if (unlikely(lv2ent_fault(ent))) {
1327		size = SPAGE_SIZE;
1328		goto done;
1329	}
1330
1331	if (lv2ent_small(ent)) {
1332		exynos_iommu_set_pte(ent, 0);
1333		size = SPAGE_SIZE;
1334		domain->lv2entcnt[lv1ent_offset(iova)] += 1;
1335		goto done;
1336	}
1337
1338	/* lv1ent_large(ent) == true here */
1339	if (WARN_ON(size < LPAGE_SIZE)) {
1340		err_pgsize = LPAGE_SIZE;
1341		goto err;
1342	}
1343
1344	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent),
1345				sizeof(*ent) * SPAGES_PER_LPAGE,
1346				DMA_TO_DEVICE);
1347	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
1348	dma_sync_single_for_device(dma_dev, virt_to_phys(ent),
1349				   sizeof(*ent) * SPAGES_PER_LPAGE,
1350				   DMA_TO_DEVICE);
1351	size = LPAGE_SIZE;
1352	domain->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
1353done:
1354	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1355
1356	exynos_iommu_tlb_invalidate_entry(domain, iova, size);
1357
1358	return size;
1359err:
1360	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1361
1362	pr_err("%s: Failed: size(%#zx) @ %#x is smaller than page size %#zx\n",
1363		__func__, size, iova, err_pgsize);
1364
1365	return 0;
1366}
1367
1368static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
1369					  dma_addr_t iova)
1370{
1371	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1372	sysmmu_pte_t *entry;
1373	unsigned long flags;
1374	phys_addr_t phys = 0;
1375
1376	spin_lock_irqsave(&domain->pgtablelock, flags);
1377
1378	entry = section_entry(domain->pgtable, iova);
1379
1380	if (lv1ent_section(entry)) {
1381		phys = section_phys(entry) + section_offs(iova);
1382	} else if (lv1ent_page(entry)) {
1383		entry = page_entry(entry, iova);
1384
1385		if (lv2ent_large(entry))
1386			phys = lpage_phys(entry) + lpage_offs(iova);
1387		else if (lv2ent_small(entry))
1388			phys = spage_phys(entry) + spage_offs(iova);
1389	}
1390
1391	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1392
1393	return phys;
1394}
1395
1396static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
1397{
1398	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1399	struct sysmmu_drvdata *data;
1400
1401	if (!has_sysmmu(dev))
1402		return ERR_PTR(-ENODEV);
1403
1404	list_for_each_entry(data, &owner->controllers, owner_node) {
1405		/*
1406		 * SYSMMU will be runtime activated via device link
1407		 * (dependency) to its master device, so there are no
1408		 * direct calls to pm_runtime_get/put in this driver.
1409		 */
1410		data->link = device_link_add(dev, data->sysmmu,
1411					     DL_FLAG_STATELESS |
1412					     DL_FLAG_PM_RUNTIME);
1413	}
1414
1415	/* There is always at least one entry, see exynos_iommu_of_xlate() */
1416	data = list_first_entry(&owner->controllers,
1417				struct sysmmu_drvdata, owner_node);
1418
1419	return &data->iommu;
1420}
1421
1422static void exynos_iommu_release_device(struct device *dev)
1423{
1424	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1425	struct sysmmu_drvdata *data;
1426
1427	WARN_ON(exynos_iommu_identity_attach(&exynos_identity_domain, dev));
1428
1429	list_for_each_entry(data, &owner->controllers, owner_node)
1430		device_link_del(data->link);
1431}
1432
1433static int exynos_iommu_of_xlate(struct device *dev,
1434				 const struct of_phandle_args *spec)
1435{
1436	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
1437	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1438	struct sysmmu_drvdata *data, *entry;
1439
1440	if (!sysmmu)
1441		return -ENODEV;
1442
1443	data = platform_get_drvdata(sysmmu);
1444	if (!data) {
1445		put_device(&sysmmu->dev);
1446		return -ENODEV;
1447	}
1448
1449	if (!owner) {
1450		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
1451		if (!owner) {
1452			put_device(&sysmmu->dev);
1453			return -ENOMEM;
1454		}
1455
1456		INIT_LIST_HEAD(&owner->controllers);
1457		mutex_init(&owner->rpm_lock);
1458		owner->domain = &exynos_identity_domain;
1459		dev_iommu_priv_set(dev, owner);
1460	}
1461
1462	list_for_each_entry(entry, &owner->controllers, owner_node)
1463		if (entry == data)
1464			return 0;
1465
1466	list_add_tail(&data->owner_node, &owner->controllers);
1467	data->master = dev;
1468
1469	return 0;
1470}
1471
1472static const struct iommu_ops exynos_iommu_ops = {
1473	.identity_domain = &exynos_identity_domain,
1474	.domain_alloc_paging = exynos_iommu_domain_alloc_paging,
1475	.device_group = generic_device_group,
1476	.probe_device = exynos_iommu_probe_device,
1477	.release_device = exynos_iommu_release_device,
1478	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
1479	.of_xlate = exynos_iommu_of_xlate,
1480	.default_domain_ops = &(const struct iommu_domain_ops) {
1481		.attach_dev	= exynos_iommu_attach_device,
1482		.map_pages	= exynos_iommu_map,
1483		.unmap_pages	= exynos_iommu_unmap,
1484		.iova_to_phys	= exynos_iommu_iova_to_phys,
1485		.free		= exynos_iommu_domain_free,
1486	}
1487};
1488
1489static int __init exynos_iommu_init(void)
1490{
1491	struct device_node *np;
1492	int ret;
1493
1494	np = of_find_matching_node(NULL, sysmmu_of_match);
1495	if (!np)
1496		return 0;
1497
1498	of_node_put(np);
1499
1500	lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table",
1501				LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL);
1502	if (!lv2table_kmem_cache) {
1503		pr_err("%s: Failed to create kmem cache\n", __func__);
1504		return -ENOMEM;
1505	}
1506
1507	zero_lv2_table = kmem_cache_zalloc(lv2table_kmem_cache, GFP_KERNEL);
1508	if (zero_lv2_table == NULL) {
1509		pr_err("%s: Failed to allocate zero level2 page table\n",
1510			__func__);
1511		ret = -ENOMEM;
1512		goto err_zero_lv2;
1513	}
1514
1515	ret = platform_driver_register(&exynos_sysmmu_driver);
1516	if (ret) {
1517		pr_err("%s: Failed to register driver\n", __func__);
1518		goto err_reg_driver;
1519	}
1520
1521	return 0;
1522err_reg_driver:
1523	kmem_cache_free(lv2table_kmem_cache, zero_lv2_table);
1524err_zero_lv2:
1525	kmem_cache_destroy(lv2table_kmem_cache);
1526	return ret;
1527}
1528core_initcall(exynos_iommu_init);
1529