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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_iommu.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/slab.h>
25 #include <linux/dma-iommu.h>
26 
27 typedef u32 sysmmu_iova_t;
28 typedef u32 sysmmu_pte_t;
29 
30 /* We do not consider super section mapping (16MB) */
31 #define SECT_ORDER 20
32 #define LPAGE_ORDER 16
33 #define SPAGE_ORDER 12
34 
35 #define SECT_SIZE (1 << SECT_ORDER)
36 #define LPAGE_SIZE (1 << LPAGE_ORDER)
37 #define SPAGE_SIZE (1 << SPAGE_ORDER)
38 
39 #define SECT_MASK (~(SECT_SIZE - 1))
40 #define LPAGE_MASK (~(LPAGE_SIZE - 1))
41 #define SPAGE_MASK (~(SPAGE_SIZE - 1))
42 
43 #define lv1ent_fault(sent) ((*(sent) == ZERO_LV2LINK) || \
44 			   ((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
45 #define lv1ent_zero(sent) (*(sent) == ZERO_LV2LINK)
46 #define lv1ent_page_zero(sent) ((*(sent) & 3) == 1)
47 #define lv1ent_page(sent) ((*(sent) != ZERO_LV2LINK) && \
48 			  ((*(sent) & 3) == 1))
49 #define lv1ent_section(sent) ((*(sent) & 3) == 2)
50 
51 #define lv2ent_fault(pent) ((*(pent) & 3) == 0)
52 #define lv2ent_small(pent) ((*(pent) & 2) == 2)
53 #define lv2ent_large(pent) ((*(pent) & 3) == 1)
54 
55 /*
56  * v1.x - v3.x SYSMMU supports 32bit physical and 32bit virtual address spaces
57  * v5.0 introduced support for 36bit physical address space by shifting
58  * all page entry values by 4 bits.
59  * All SYSMMU controllers in the system support the address spaces of the same
60  * size, so PG_ENT_SHIFT can be initialized on first SYSMMU probe to proper
61  * value (0 or 4).
62  */
63 static short PG_ENT_SHIFT = -1;
64 #define SYSMMU_PG_ENT_SHIFT 0
65 #define SYSMMU_V5_PG_ENT_SHIFT 4
66 
67 static const sysmmu_pte_t *LV1_PROT;
68 static const sysmmu_pte_t SYSMMU_LV1_PROT[] = {
69 	((0 << 15) | (0 << 10)), /* no access */
70 	((1 << 15) | (1 << 10)), /* IOMMU_READ only */
71 	((0 << 15) | (1 << 10)), /* IOMMU_WRITE not supported, use read/write */
72 	((0 << 15) | (1 << 10)), /* IOMMU_READ | IOMMU_WRITE */
73 };
74 static const sysmmu_pte_t SYSMMU_V5_LV1_PROT[] = {
75 	(0 << 4), /* no access */
76 	(1 << 4), /* IOMMU_READ only */
77 	(2 << 4), /* IOMMU_WRITE only */
78 	(3 << 4), /* IOMMU_READ | IOMMU_WRITE */
79 };
80 
81 static const sysmmu_pte_t *LV2_PROT;
82 static const sysmmu_pte_t SYSMMU_LV2_PROT[] = {
83 	((0 << 9) | (0 << 4)), /* no access */
84 	((1 << 9) | (1 << 4)), /* IOMMU_READ only */
85 	((0 << 9) | (1 << 4)), /* IOMMU_WRITE not supported, use read/write */
86 	((0 << 9) | (1 << 4)), /* IOMMU_READ | IOMMU_WRITE */
87 };
88 static const sysmmu_pte_t SYSMMU_V5_LV2_PROT[] = {
89 	(0 << 2), /* no access */
90 	(1 << 2), /* IOMMU_READ only */
91 	(2 << 2), /* IOMMU_WRITE only */
92 	(3 << 2), /* IOMMU_READ | IOMMU_WRITE */
93 };
94 
95 #define SYSMMU_SUPPORTED_PROT_BITS (IOMMU_READ | IOMMU_WRITE)
96 
97 #define sect_to_phys(ent) (((phys_addr_t) ent) << PG_ENT_SHIFT)
98 #define section_phys(sent) (sect_to_phys(*(sent)) & SECT_MASK)
99 #define section_offs(iova) (iova & (SECT_SIZE - 1))
100 #define lpage_phys(pent) (sect_to_phys(*(pent)) & LPAGE_MASK)
101 #define lpage_offs(iova) (iova & (LPAGE_SIZE - 1))
102 #define spage_phys(pent) (sect_to_phys(*(pent)) & SPAGE_MASK)
103 #define spage_offs(iova) (iova & (SPAGE_SIZE - 1))
104 
105 #define NUM_LV1ENTRIES 4096
106 #define NUM_LV2ENTRIES (SECT_SIZE / SPAGE_SIZE)
107 
lv1ent_offset(sysmmu_iova_t iova)108 static u32 lv1ent_offset(sysmmu_iova_t iova)
109 {
110 	return iova >> SECT_ORDER;
111 }
112 
lv2ent_offset(sysmmu_iova_t iova)113 static u32 lv2ent_offset(sysmmu_iova_t iova)
114 {
115 	return (iova >> SPAGE_ORDER) & (NUM_LV2ENTRIES - 1);
116 }
117 
118 #define LV1TABLE_SIZE (NUM_LV1ENTRIES * sizeof(sysmmu_pte_t))
119 #define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(sysmmu_pte_t))
120 
121 #define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
122 #define lv2table_base(sent) (sect_to_phys(*(sent) & 0xFFFFFFC0))
123 
124 #define mk_lv1ent_sect(pa, prot) ((pa >> PG_ENT_SHIFT) | LV1_PROT[prot] | 2)
125 #define mk_lv1ent_page(pa) ((pa >> PG_ENT_SHIFT) | 1)
126 #define mk_lv2ent_lpage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 1)
127 #define mk_lv2ent_spage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 2)
128 
129 #define CTRL_ENABLE	0x5
130 #define CTRL_BLOCK	0x7
131 #define CTRL_DISABLE	0x0
132 
133 #define CFG_LRU		0x1
134 #define CFG_EAP		(1 << 2)
135 #define CFG_QOS(n)	((n & 0xF) << 7)
136 #define CFG_ACGEN	(1 << 24) /* System MMU 3.3 only */
137 #define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
138 #define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */
139 
140 /* common registers */
141 #define REG_MMU_CTRL		0x000
142 #define REG_MMU_CFG		0x004
143 #define REG_MMU_STATUS		0x008
144 #define REG_MMU_VERSION		0x034
145 
146 #define MMU_MAJ_VER(val)	((val) >> 7)
147 #define MMU_MIN_VER(val)	((val) & 0x7F)
148 #define MMU_RAW_VER(reg)	(((reg) >> 21) & ((1 << 11) - 1)) /* 11 bits */
149 
150 #define MAKE_MMU_VER(maj, min)	((((maj) & 0xF) << 7) | ((min) & 0x7F))
151 
152 /* v1.x - v3.x registers */
153 #define REG_MMU_FLUSH		0x00C
154 #define REG_MMU_FLUSH_ENTRY	0x010
155 #define REG_PT_BASE_ADDR	0x014
156 #define REG_INT_STATUS		0x018
157 #define REG_INT_CLEAR		0x01C
158 
159 #define REG_PAGE_FAULT_ADDR	0x024
160 #define REG_AW_FAULT_ADDR	0x028
161 #define REG_AR_FAULT_ADDR	0x02C
162 #define REG_DEFAULT_SLAVE_ADDR	0x030
163 
164 /* v5.x registers */
165 #define REG_V5_PT_BASE_PFN	0x00C
166 #define REG_V5_MMU_FLUSH_ALL	0x010
167 #define REG_V5_MMU_FLUSH_ENTRY	0x014
168 #define REG_V5_MMU_FLUSH_RANGE	0x018
169 #define REG_V5_MMU_FLUSH_START	0x020
170 #define REG_V5_MMU_FLUSH_END	0x024
171 #define REG_V5_INT_STATUS	0x060
172 #define REG_V5_INT_CLEAR	0x064
173 #define REG_V5_FAULT_AR_VA	0x070
174 #define REG_V5_FAULT_AW_VA	0x080
175 
176 #define has_sysmmu(dev)		(dev_iommu_priv_get(dev) != NULL)
177 
178 static struct device *dma_dev;
179 static struct kmem_cache *lv2table_kmem_cache;
180 static sysmmu_pte_t *zero_lv2_table;
181 #define ZERO_LV2LINK mk_lv1ent_page(virt_to_phys(zero_lv2_table))
182 
section_entry(sysmmu_pte_t * pgtable,sysmmu_iova_t iova)183 static sysmmu_pte_t *section_entry(sysmmu_pte_t *pgtable, sysmmu_iova_t iova)
184 {
185 	return pgtable + lv1ent_offset(iova);
186 }
187 
page_entry(sysmmu_pte_t * sent,sysmmu_iova_t iova)188 static sysmmu_pte_t *page_entry(sysmmu_pte_t *sent, sysmmu_iova_t iova)
189 {
190 	return (sysmmu_pte_t *)phys_to_virt(
191 				lv2table_base(sent)) + lv2ent_offset(iova);
192 }
193 
194 /*
195  * IOMMU fault information register
196  */
197 struct sysmmu_fault_info {
198 	unsigned int bit;	/* bit number in STATUS register */
199 	unsigned short addr_reg; /* register to read VA fault address */
200 	const char *name;	/* human readable fault name */
201 	unsigned int type;	/* fault type for report_iommu_fault */
202 };
203 
204 static const struct sysmmu_fault_info sysmmu_faults[] = {
205 	{ 0, REG_PAGE_FAULT_ADDR, "PAGE", IOMMU_FAULT_READ },
206 	{ 1, REG_AR_FAULT_ADDR, "AR MULTI-HIT", IOMMU_FAULT_READ },
207 	{ 2, REG_AW_FAULT_ADDR, "AW MULTI-HIT", IOMMU_FAULT_WRITE },
208 	{ 3, REG_DEFAULT_SLAVE_ADDR, "BUS ERROR", IOMMU_FAULT_READ },
209 	{ 4, REG_AR_FAULT_ADDR, "AR SECURITY PROTECTION", IOMMU_FAULT_READ },
210 	{ 5, REG_AR_FAULT_ADDR, "AR ACCESS PROTECTION", IOMMU_FAULT_READ },
211 	{ 6, REG_AW_FAULT_ADDR, "AW SECURITY PROTECTION", IOMMU_FAULT_WRITE },
212 	{ 7, REG_AW_FAULT_ADDR, "AW ACCESS PROTECTION", IOMMU_FAULT_WRITE },
213 };
214 
215 static const struct sysmmu_fault_info sysmmu_v5_faults[] = {
216 	{ 0, REG_V5_FAULT_AR_VA, "AR PTW", IOMMU_FAULT_READ },
217 	{ 1, REG_V5_FAULT_AR_VA, "AR PAGE", IOMMU_FAULT_READ },
218 	{ 2, REG_V5_FAULT_AR_VA, "AR MULTI-HIT", IOMMU_FAULT_READ },
219 	{ 3, REG_V5_FAULT_AR_VA, "AR ACCESS PROTECTION", IOMMU_FAULT_READ },
220 	{ 4, REG_V5_FAULT_AR_VA, "AR SECURITY PROTECTION", IOMMU_FAULT_READ },
221 	{ 16, REG_V5_FAULT_AW_VA, "AW PTW", IOMMU_FAULT_WRITE },
222 	{ 17, REG_V5_FAULT_AW_VA, "AW PAGE", IOMMU_FAULT_WRITE },
223 	{ 18, REG_V5_FAULT_AW_VA, "AW MULTI-HIT", IOMMU_FAULT_WRITE },
224 	{ 19, REG_V5_FAULT_AW_VA, "AW ACCESS PROTECTION", IOMMU_FAULT_WRITE },
225 	{ 20, REG_V5_FAULT_AW_VA, "AW SECURITY PROTECTION", IOMMU_FAULT_WRITE },
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 */
234 struct 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  */
246 struct 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 
255 /*
256  * This structure hold all data of a single SYSMMU controller, this includes
257  * hw resources like registers and clocks, pointers and list nodes to connect
258  * it to all other structures, internal state and parameters read from device
259  * tree. It is usually referenced by 'data' pointer.
260  */
261 struct sysmmu_drvdata {
262 	struct device *sysmmu;		/* SYSMMU controller device */
263 	struct device *master;		/* master device (owner) */
264 	struct device_link *link;	/* runtime PM link to master */
265 	void __iomem *sfrbase;		/* our registers */
266 	struct clk *clk;		/* SYSMMU's clock */
267 	struct clk *aclk;		/* SYSMMU's aclk clock */
268 	struct clk *pclk;		/* SYSMMU's pclk clock */
269 	struct clk *clk_master;		/* master's device clock */
270 	spinlock_t lock;		/* lock for modyfying state */
271 	bool active;			/* current status */
272 	struct exynos_iommu_domain *domain; /* domain we belong to */
273 	struct list_head domain_node;	/* node for domain clients list */
274 	struct list_head owner_node;	/* node for owner controllers list */
275 	phys_addr_t pgtable;		/* assigned page table structure */
276 	unsigned int version;		/* our version */
277 
278 	struct iommu_device iommu;	/* IOMMU core handle */
279 };
280 
to_exynos_domain(struct iommu_domain * dom)281 static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
282 {
283 	return container_of(dom, struct exynos_iommu_domain, domain);
284 }
285 
sysmmu_unblock(struct sysmmu_drvdata * data)286 static void sysmmu_unblock(struct sysmmu_drvdata *data)
287 {
288 	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
289 }
290 
sysmmu_block(struct sysmmu_drvdata * data)291 static bool sysmmu_block(struct sysmmu_drvdata *data)
292 {
293 	int i = 120;
294 
295 	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
296 	while ((i > 0) && !(readl(data->sfrbase + REG_MMU_STATUS) & 1))
297 		--i;
298 
299 	if (!(readl(data->sfrbase + REG_MMU_STATUS) & 1)) {
300 		sysmmu_unblock(data);
301 		return false;
302 	}
303 
304 	return true;
305 }
306 
__sysmmu_tlb_invalidate(struct sysmmu_drvdata * data)307 static void __sysmmu_tlb_invalidate(struct sysmmu_drvdata *data)
308 {
309 	if (MMU_MAJ_VER(data->version) < 5)
310 		writel(0x1, data->sfrbase + REG_MMU_FLUSH);
311 	else
312 		writel(0x1, data->sfrbase + REG_V5_MMU_FLUSH_ALL);
313 }
314 
__sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata * data,sysmmu_iova_t iova,unsigned int num_inv)315 static void __sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
316 				sysmmu_iova_t iova, unsigned int num_inv)
317 {
318 	unsigned int i;
319 
320 	if (MMU_MAJ_VER(data->version) < 5) {
321 		for (i = 0; i < num_inv; i++) {
322 			writel((iova & SPAGE_MASK) | 1,
323 				     data->sfrbase + REG_MMU_FLUSH_ENTRY);
324 			iova += SPAGE_SIZE;
325 		}
326 	} else {
327 		if (num_inv == 1) {
328 			writel((iova & SPAGE_MASK) | 1,
329 				     data->sfrbase + REG_V5_MMU_FLUSH_ENTRY);
330 		} else {
331 			writel((iova & SPAGE_MASK),
332 				     data->sfrbase + REG_V5_MMU_FLUSH_START);
333 			writel((iova & SPAGE_MASK) + (num_inv - 1) * SPAGE_SIZE,
334 				     data->sfrbase + REG_V5_MMU_FLUSH_END);
335 			writel(1, data->sfrbase + REG_V5_MMU_FLUSH_RANGE);
336 		}
337 	}
338 }
339 
__sysmmu_set_ptbase(struct sysmmu_drvdata * data,phys_addr_t pgd)340 static void __sysmmu_set_ptbase(struct sysmmu_drvdata *data, phys_addr_t pgd)
341 {
342 	if (MMU_MAJ_VER(data->version) < 5)
343 		writel(pgd, data->sfrbase + REG_PT_BASE_ADDR);
344 	else
345 		writel(pgd >> PAGE_SHIFT,
346 			     data->sfrbase + REG_V5_PT_BASE_PFN);
347 
348 	__sysmmu_tlb_invalidate(data);
349 }
350 
__sysmmu_enable_clocks(struct sysmmu_drvdata * data)351 static void __sysmmu_enable_clocks(struct sysmmu_drvdata *data)
352 {
353 	BUG_ON(clk_prepare_enable(data->clk_master));
354 	BUG_ON(clk_prepare_enable(data->clk));
355 	BUG_ON(clk_prepare_enable(data->pclk));
356 	BUG_ON(clk_prepare_enable(data->aclk));
357 }
358 
__sysmmu_disable_clocks(struct sysmmu_drvdata * data)359 static void __sysmmu_disable_clocks(struct sysmmu_drvdata *data)
360 {
361 	clk_disable_unprepare(data->aclk);
362 	clk_disable_unprepare(data->pclk);
363 	clk_disable_unprepare(data->clk);
364 	clk_disable_unprepare(data->clk_master);
365 }
366 
__sysmmu_get_version(struct sysmmu_drvdata * data)367 static void __sysmmu_get_version(struct sysmmu_drvdata *data)
368 {
369 	u32 ver;
370 
371 	__sysmmu_enable_clocks(data);
372 
373 	ver = readl(data->sfrbase + REG_MMU_VERSION);
374 
375 	/* controllers on some SoCs don't report proper version */
376 	if (ver == 0x80000001u)
377 		data->version = MAKE_MMU_VER(1, 0);
378 	else
379 		data->version = MMU_RAW_VER(ver);
380 
381 	dev_dbg(data->sysmmu, "hardware version: %d.%d\n",
382 		MMU_MAJ_VER(data->version), MMU_MIN_VER(data->version));
383 
384 	__sysmmu_disable_clocks(data);
385 }
386 
show_fault_information(struct sysmmu_drvdata * data,const struct sysmmu_fault_info * finfo,sysmmu_iova_t fault_addr)387 static void show_fault_information(struct sysmmu_drvdata *data,
388 				   const struct sysmmu_fault_info *finfo,
389 				   sysmmu_iova_t fault_addr)
390 {
391 	sysmmu_pte_t *ent;
392 
393 	dev_err(data->sysmmu, "%s: %s FAULT occurred at %#x\n",
394 		dev_name(data->master), finfo->name, fault_addr);
395 	dev_dbg(data->sysmmu, "Page table base: %pa\n", &data->pgtable);
396 	ent = section_entry(phys_to_virt(data->pgtable), fault_addr);
397 	dev_dbg(data->sysmmu, "\tLv1 entry: %#x\n", *ent);
398 	if (lv1ent_page(ent)) {
399 		ent = page_entry(ent, fault_addr);
400 		dev_dbg(data->sysmmu, "\t Lv2 entry: %#x\n", *ent);
401 	}
402 }
403 
exynos_sysmmu_irq(int irq,void * dev_id)404 static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
405 {
406 	/* SYSMMU is in blocked state when interrupt occurred. */
407 	struct sysmmu_drvdata *data = dev_id;
408 	const struct sysmmu_fault_info *finfo;
409 	unsigned int i, n, itype;
410 	sysmmu_iova_t fault_addr = -1;
411 	unsigned short reg_status, reg_clear;
412 	int ret = -ENOSYS;
413 
414 	WARN_ON(!data->active);
415 
416 	if (MMU_MAJ_VER(data->version) < 5) {
417 		reg_status = REG_INT_STATUS;
418 		reg_clear = REG_INT_CLEAR;
419 		finfo = sysmmu_faults;
420 		n = ARRAY_SIZE(sysmmu_faults);
421 	} else {
422 		reg_status = REG_V5_INT_STATUS;
423 		reg_clear = REG_V5_INT_CLEAR;
424 		finfo = sysmmu_v5_faults;
425 		n = ARRAY_SIZE(sysmmu_v5_faults);
426 	}
427 
428 	spin_lock(&data->lock);
429 
430 	clk_enable(data->clk_master);
431 
432 	itype = __ffs(readl(data->sfrbase + reg_status));
433 	for (i = 0; i < n; i++, finfo++)
434 		if (finfo->bit == itype)
435 			break;
436 	/* unknown/unsupported fault */
437 	BUG_ON(i == n);
438 
439 	/* print debug message */
440 	fault_addr = readl(data->sfrbase + finfo->addr_reg);
441 	show_fault_information(data, finfo, fault_addr);
442 
443 	if (data->domain)
444 		ret = report_iommu_fault(&data->domain->domain,
445 					data->master, fault_addr, finfo->type);
446 	/* fault is not recovered by fault handler */
447 	BUG_ON(ret != 0);
448 
449 	writel(1 << itype, data->sfrbase + reg_clear);
450 
451 	sysmmu_unblock(data);
452 
453 	clk_disable(data->clk_master);
454 
455 	spin_unlock(&data->lock);
456 
457 	return IRQ_HANDLED;
458 }
459 
__sysmmu_disable(struct sysmmu_drvdata * data)460 static void __sysmmu_disable(struct sysmmu_drvdata *data)
461 {
462 	unsigned long flags;
463 
464 	clk_enable(data->clk_master);
465 
466 	spin_lock_irqsave(&data->lock, flags);
467 	writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
468 	writel(0, data->sfrbase + REG_MMU_CFG);
469 	data->active = false;
470 	spin_unlock_irqrestore(&data->lock, flags);
471 
472 	__sysmmu_disable_clocks(data);
473 }
474 
__sysmmu_init_config(struct sysmmu_drvdata * data)475 static void __sysmmu_init_config(struct sysmmu_drvdata *data)
476 {
477 	unsigned int cfg;
478 
479 	if (data->version <= MAKE_MMU_VER(3, 1))
480 		cfg = CFG_LRU | CFG_QOS(15);
481 	else if (data->version <= MAKE_MMU_VER(3, 2))
482 		cfg = CFG_LRU | CFG_QOS(15) | CFG_FLPDCACHE | CFG_SYSSEL;
483 	else
484 		cfg = CFG_QOS(15) | CFG_FLPDCACHE | CFG_ACGEN;
485 
486 	cfg |= CFG_EAP; /* enable access protection bits check */
487 
488 	writel(cfg, data->sfrbase + REG_MMU_CFG);
489 }
490 
__sysmmu_enable(struct sysmmu_drvdata * data)491 static void __sysmmu_enable(struct sysmmu_drvdata *data)
492 {
493 	unsigned long flags;
494 
495 	__sysmmu_enable_clocks(data);
496 
497 	spin_lock_irqsave(&data->lock, flags);
498 	writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
499 	__sysmmu_init_config(data);
500 	__sysmmu_set_ptbase(data, data->pgtable);
501 	writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
502 	data->active = true;
503 	spin_unlock_irqrestore(&data->lock, flags);
504 
505 	/*
506 	 * SYSMMU driver keeps master's clock enabled only for the short
507 	 * time, while accessing the registers. For performing address
508 	 * translation during DMA transaction it relies on the client
509 	 * driver to enable it.
510 	 */
511 	clk_disable(data->clk_master);
512 }
513 
sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata * data,sysmmu_iova_t iova)514 static void sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata *data,
515 					    sysmmu_iova_t iova)
516 {
517 	unsigned long flags;
518 
519 	spin_lock_irqsave(&data->lock, flags);
520 	if (data->active && data->version >= MAKE_MMU_VER(3, 3)) {
521 		clk_enable(data->clk_master);
522 		if (sysmmu_block(data)) {
523 			if (data->version >= MAKE_MMU_VER(5, 0))
524 				__sysmmu_tlb_invalidate(data);
525 			else
526 				__sysmmu_tlb_invalidate_entry(data, iova, 1);
527 			sysmmu_unblock(data);
528 		}
529 		clk_disable(data->clk_master);
530 	}
531 	spin_unlock_irqrestore(&data->lock, flags);
532 }
533 
sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata * data,sysmmu_iova_t iova,size_t size)534 static void sysmmu_tlb_invalidate_entry(struct sysmmu_drvdata *data,
535 					sysmmu_iova_t iova, size_t size)
536 {
537 	unsigned long flags;
538 
539 	spin_lock_irqsave(&data->lock, flags);
540 	if (data->active) {
541 		unsigned int num_inv = 1;
542 
543 		clk_enable(data->clk_master);
544 
545 		/*
546 		 * L2TLB invalidation required
547 		 * 4KB page: 1 invalidation
548 		 * 64KB page: 16 invalidations
549 		 * 1MB page: 64 invalidations
550 		 * because it is set-associative TLB
551 		 * with 8-way and 64 sets.
552 		 * 1MB page can be cached in one of all sets.
553 		 * 64KB page can be one of 16 consecutive sets.
554 		 */
555 		if (MMU_MAJ_VER(data->version) == 2)
556 			num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);
557 
558 		if (sysmmu_block(data)) {
559 			__sysmmu_tlb_invalidate_entry(data, iova, num_inv);
560 			sysmmu_unblock(data);
561 		}
562 		clk_disable(data->clk_master);
563 	}
564 	spin_unlock_irqrestore(&data->lock, flags);
565 }
566 
567 static const struct iommu_ops exynos_iommu_ops;
568 
exynos_sysmmu_probe(struct platform_device * pdev)569 static int exynos_sysmmu_probe(struct platform_device *pdev)
570 {
571 	int irq, ret;
572 	struct device *dev = &pdev->dev;
573 	struct sysmmu_drvdata *data;
574 	struct resource *res;
575 
576 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
577 	if (!data)
578 		return -ENOMEM;
579 
580 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
581 	data->sfrbase = devm_ioremap_resource(dev, res);
582 	if (IS_ERR(data->sfrbase))
583 		return PTR_ERR(data->sfrbase);
584 
585 	irq = platform_get_irq(pdev, 0);
586 	if (irq <= 0)
587 		return irq;
588 
589 	ret = devm_request_irq(dev, irq, exynos_sysmmu_irq, 0,
590 				dev_name(dev), data);
591 	if (ret) {
592 		dev_err(dev, "Unabled to register handler of irq %d\n", irq);
593 		return ret;
594 	}
595 
596 	data->clk = devm_clk_get(dev, "sysmmu");
597 	if (PTR_ERR(data->clk) == -ENOENT)
598 		data->clk = NULL;
599 	else if (IS_ERR(data->clk))
600 		return PTR_ERR(data->clk);
601 
602 	data->aclk = devm_clk_get(dev, "aclk");
603 	if (PTR_ERR(data->aclk) == -ENOENT)
604 		data->aclk = NULL;
605 	else if (IS_ERR(data->aclk))
606 		return PTR_ERR(data->aclk);
607 
608 	data->pclk = devm_clk_get(dev, "pclk");
609 	if (PTR_ERR(data->pclk) == -ENOENT)
610 		data->pclk = NULL;
611 	else if (IS_ERR(data->pclk))
612 		return PTR_ERR(data->pclk);
613 
614 	if (!data->clk && (!data->aclk || !data->pclk)) {
615 		dev_err(dev, "Failed to get device clock(s)!\n");
616 		return -ENOSYS;
617 	}
618 
619 	data->clk_master = devm_clk_get(dev, "master");
620 	if (PTR_ERR(data->clk_master) == -ENOENT)
621 		data->clk_master = NULL;
622 	else if (IS_ERR(data->clk_master))
623 		return PTR_ERR(data->clk_master);
624 
625 	data->sysmmu = dev;
626 	spin_lock_init(&data->lock);
627 
628 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
629 				     dev_name(data->sysmmu));
630 	if (ret)
631 		return ret;
632 
633 	iommu_device_set_ops(&data->iommu, &exynos_iommu_ops);
634 	iommu_device_set_fwnode(&data->iommu, &dev->of_node->fwnode);
635 
636 	ret = iommu_device_register(&data->iommu);
637 	if (ret)
638 		goto err_iommu_register;
639 
640 	platform_set_drvdata(pdev, data);
641 
642 	__sysmmu_get_version(data);
643 	if (PG_ENT_SHIFT < 0) {
644 		if (MMU_MAJ_VER(data->version) < 5) {
645 			PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;
646 			LV1_PROT = SYSMMU_LV1_PROT;
647 			LV2_PROT = SYSMMU_LV2_PROT;
648 		} else {
649 			PG_ENT_SHIFT = SYSMMU_V5_PG_ENT_SHIFT;
650 			LV1_PROT = SYSMMU_V5_LV1_PROT;
651 			LV2_PROT = SYSMMU_V5_LV2_PROT;
652 		}
653 	}
654 
655 	/*
656 	 * use the first registered sysmmu device for performing
657 	 * dma mapping operations on iommu page tables (cpu cache flush)
658 	 */
659 	if (!dma_dev)
660 		dma_dev = &pdev->dev;
661 
662 	pm_runtime_enable(dev);
663 
664 	return 0;
665 
666 err_iommu_register:
667 	iommu_device_sysfs_remove(&data->iommu);
668 	return ret;
669 }
670 
exynos_sysmmu_suspend(struct device * dev)671 static int __maybe_unused exynos_sysmmu_suspend(struct device *dev)
672 {
673 	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
674 	struct device *master = data->master;
675 
676 	if (master) {
677 		struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
678 
679 		mutex_lock(&owner->rpm_lock);
680 		if (data->domain) {
681 			dev_dbg(data->sysmmu, "saving state\n");
682 			__sysmmu_disable(data);
683 		}
684 		mutex_unlock(&owner->rpm_lock);
685 	}
686 	return 0;
687 }
688 
exynos_sysmmu_resume(struct device * dev)689 static int __maybe_unused exynos_sysmmu_resume(struct device *dev)
690 {
691 	struct sysmmu_drvdata *data = dev_get_drvdata(dev);
692 	struct device *master = data->master;
693 
694 	if (master) {
695 		struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
696 
697 		mutex_lock(&owner->rpm_lock);
698 		if (data->domain) {
699 			dev_dbg(data->sysmmu, "restoring state\n");
700 			__sysmmu_enable(data);
701 		}
702 		mutex_unlock(&owner->rpm_lock);
703 	}
704 	return 0;
705 }
706 
707 static const struct dev_pm_ops sysmmu_pm_ops = {
708 	SET_RUNTIME_PM_OPS(exynos_sysmmu_suspend, exynos_sysmmu_resume, NULL)
709 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
710 				pm_runtime_force_resume)
711 };
712 
713 static const struct of_device_id sysmmu_of_match[] = {
714 	{ .compatible	= "samsung,exynos-sysmmu", },
715 	{ },
716 };
717 
718 static struct platform_driver exynos_sysmmu_driver __refdata = {
719 	.probe	= exynos_sysmmu_probe,
720 	.driver	= {
721 		.name		= "exynos-sysmmu",
722 		.of_match_table	= sysmmu_of_match,
723 		.pm		= &sysmmu_pm_ops,
724 		.suppress_bind_attrs = true,
725 	}
726 };
727 
exynos_iommu_set_pte(sysmmu_pte_t * ent,sysmmu_pte_t val)728 static inline void exynos_iommu_set_pte(sysmmu_pte_t *ent, sysmmu_pte_t val)
729 {
730 	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent), sizeof(*ent),
731 				DMA_TO_DEVICE);
732 	*ent = cpu_to_le32(val);
733 	dma_sync_single_for_device(dma_dev, virt_to_phys(ent), sizeof(*ent),
734 				   DMA_TO_DEVICE);
735 }
736 
exynos_iommu_domain_alloc(unsigned type)737 static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
738 {
739 	struct exynos_iommu_domain *domain;
740 	dma_addr_t handle;
741 	int i;
742 
743 	/* Check if correct PTE offsets are initialized */
744 	BUG_ON(PG_ENT_SHIFT < 0 || !dma_dev);
745 
746 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
747 	if (!domain)
748 		return NULL;
749 
750 	if (type == IOMMU_DOMAIN_DMA) {
751 		if (iommu_get_dma_cookie(&domain->domain) != 0)
752 			goto err_pgtable;
753 	} else if (type != IOMMU_DOMAIN_UNMANAGED) {
754 		goto err_pgtable;
755 	}
756 
757 	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
758 	if (!domain->pgtable)
759 		goto err_dma_cookie;
760 
761 	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
762 	if (!domain->lv2entcnt)
763 		goto err_counter;
764 
765 	/* Workaround for System MMU v3.3 to prevent caching 1MiB mapping */
766 	for (i = 0; i < NUM_LV1ENTRIES; i++)
767 		domain->pgtable[i] = ZERO_LV2LINK;
768 
769 	handle = dma_map_single(dma_dev, domain->pgtable, LV1TABLE_SIZE,
770 				DMA_TO_DEVICE);
771 	/* For mapping page table entries we rely on dma == phys */
772 	BUG_ON(handle != virt_to_phys(domain->pgtable));
773 	if (dma_mapping_error(dma_dev, handle))
774 		goto err_lv2ent;
775 
776 	spin_lock_init(&domain->lock);
777 	spin_lock_init(&domain->pgtablelock);
778 	INIT_LIST_HEAD(&domain->clients);
779 
780 	domain->domain.geometry.aperture_start = 0;
781 	domain->domain.geometry.aperture_end   = ~0UL;
782 	domain->domain.geometry.force_aperture = true;
783 
784 	return &domain->domain;
785 
786 err_lv2ent:
787 	free_pages((unsigned long)domain->lv2entcnt, 1);
788 err_counter:
789 	free_pages((unsigned long)domain->pgtable, 2);
790 err_dma_cookie:
791 	if (type == IOMMU_DOMAIN_DMA)
792 		iommu_put_dma_cookie(&domain->domain);
793 err_pgtable:
794 	kfree(domain);
795 	return NULL;
796 }
797 
exynos_iommu_domain_free(struct iommu_domain * iommu_domain)798 static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
799 {
800 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
801 	struct sysmmu_drvdata *data, *next;
802 	unsigned long flags;
803 	int i;
804 
805 	WARN_ON(!list_empty(&domain->clients));
806 
807 	spin_lock_irqsave(&domain->lock, flags);
808 
809 	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
810 		spin_lock(&data->lock);
811 		__sysmmu_disable(data);
812 		data->pgtable = 0;
813 		data->domain = NULL;
814 		list_del_init(&data->domain_node);
815 		spin_unlock(&data->lock);
816 	}
817 
818 	spin_unlock_irqrestore(&domain->lock, flags);
819 
820 	if (iommu_domain->type == IOMMU_DOMAIN_DMA)
821 		iommu_put_dma_cookie(iommu_domain);
822 
823 	dma_unmap_single(dma_dev, virt_to_phys(domain->pgtable), LV1TABLE_SIZE,
824 			 DMA_TO_DEVICE);
825 
826 	for (i = 0; i < NUM_LV1ENTRIES; i++)
827 		if (lv1ent_page(domain->pgtable + i)) {
828 			phys_addr_t base = lv2table_base(domain->pgtable + i);
829 
830 			dma_unmap_single(dma_dev, base, LV2TABLE_SIZE,
831 					 DMA_TO_DEVICE);
832 			kmem_cache_free(lv2table_kmem_cache,
833 					phys_to_virt(base));
834 		}
835 
836 	free_pages((unsigned long)domain->pgtable, 2);
837 	free_pages((unsigned long)domain->lv2entcnt, 1);
838 	kfree(domain);
839 }
840 
exynos_iommu_detach_device(struct iommu_domain * iommu_domain,struct device * dev)841 static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain,
842 				    struct device *dev)
843 {
844 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
845 	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
846 	phys_addr_t pagetable = virt_to_phys(domain->pgtable);
847 	struct sysmmu_drvdata *data, *next;
848 	unsigned long flags;
849 
850 	if (!has_sysmmu(dev) || owner->domain != iommu_domain)
851 		return;
852 
853 	mutex_lock(&owner->rpm_lock);
854 
855 	list_for_each_entry(data, &owner->controllers, owner_node) {
856 		pm_runtime_get_noresume(data->sysmmu);
857 		if (pm_runtime_active(data->sysmmu))
858 			__sysmmu_disable(data);
859 		pm_runtime_put(data->sysmmu);
860 	}
861 
862 	spin_lock_irqsave(&domain->lock, flags);
863 	list_for_each_entry_safe(data, next, &domain->clients, domain_node) {
864 		spin_lock(&data->lock);
865 		data->pgtable = 0;
866 		data->domain = NULL;
867 		list_del_init(&data->domain_node);
868 		spin_unlock(&data->lock);
869 	}
870 	owner->domain = NULL;
871 	spin_unlock_irqrestore(&domain->lock, flags);
872 
873 	mutex_unlock(&owner->rpm_lock);
874 
875 	dev_dbg(dev, "%s: Detached IOMMU with pgtable %pa\n", __func__,
876 		&pagetable);
877 }
878 
exynos_iommu_attach_device(struct iommu_domain * iommu_domain,struct device * dev)879 static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain,
880 				   struct device *dev)
881 {
882 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
883 	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
884 	struct sysmmu_drvdata *data;
885 	phys_addr_t pagetable = virt_to_phys(domain->pgtable);
886 	unsigned long flags;
887 
888 	if (!has_sysmmu(dev))
889 		return -ENODEV;
890 
891 	if (owner->domain)
892 		exynos_iommu_detach_device(owner->domain, dev);
893 
894 	mutex_lock(&owner->rpm_lock);
895 
896 	spin_lock_irqsave(&domain->lock, flags);
897 	list_for_each_entry(data, &owner->controllers, owner_node) {
898 		spin_lock(&data->lock);
899 		data->pgtable = pagetable;
900 		data->domain = domain;
901 		list_add_tail(&data->domain_node, &domain->clients);
902 		spin_unlock(&data->lock);
903 	}
904 	owner->domain = iommu_domain;
905 	spin_unlock_irqrestore(&domain->lock, flags);
906 
907 	list_for_each_entry(data, &owner->controllers, owner_node) {
908 		pm_runtime_get_noresume(data->sysmmu);
909 		if (pm_runtime_active(data->sysmmu))
910 			__sysmmu_enable(data);
911 		pm_runtime_put(data->sysmmu);
912 	}
913 
914 	mutex_unlock(&owner->rpm_lock);
915 
916 	dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa\n", __func__,
917 		&pagetable);
918 
919 	return 0;
920 }
921 
alloc_lv2entry(struct exynos_iommu_domain * domain,sysmmu_pte_t * sent,sysmmu_iova_t iova,short * pgcounter)922 static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
923 		sysmmu_pte_t *sent, sysmmu_iova_t iova, short *pgcounter)
924 {
925 	if (lv1ent_section(sent)) {
926 		WARN(1, "Trying mapping on %#08x mapped with 1MiB page", iova);
927 		return ERR_PTR(-EADDRINUSE);
928 	}
929 
930 	if (lv1ent_fault(sent)) {
931 		dma_addr_t handle;
932 		sysmmu_pte_t *pent;
933 		bool need_flush_flpd_cache = lv1ent_zero(sent);
934 
935 		pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
936 		BUG_ON((uintptr_t)pent & (LV2TABLE_SIZE - 1));
937 		if (!pent)
938 			return ERR_PTR(-ENOMEM);
939 
940 		exynos_iommu_set_pte(sent, mk_lv1ent_page(virt_to_phys(pent)));
941 		kmemleak_ignore(pent);
942 		*pgcounter = NUM_LV2ENTRIES;
943 		handle = dma_map_single(dma_dev, pent, LV2TABLE_SIZE,
944 					DMA_TO_DEVICE);
945 		if (dma_mapping_error(dma_dev, handle)) {
946 			kmem_cache_free(lv2table_kmem_cache, pent);
947 			return ERR_PTR(-EADDRINUSE);
948 		}
949 
950 		/*
951 		 * If pre-fetched SLPD is a faulty SLPD in zero_l2_table,
952 		 * FLPD cache may cache the address of zero_l2_table. This
953 		 * function replaces the zero_l2_table with new L2 page table
954 		 * to write valid mappings.
955 		 * Accessing the valid area may cause page fault since FLPD
956 		 * cache may still cache zero_l2_table for the valid area
957 		 * instead of new L2 page table that has the mapping
958 		 * information of the valid area.
959 		 * Thus any replacement of zero_l2_table with other valid L2
960 		 * page table must involve FLPD cache invalidation for System
961 		 * MMU v3.3.
962 		 * FLPD cache invalidation is performed with TLB invalidation
963 		 * by VPN without blocking. It is safe to invalidate TLB without
964 		 * blocking because the target address of TLB invalidation is
965 		 * not currently mapped.
966 		 */
967 		if (need_flush_flpd_cache) {
968 			struct sysmmu_drvdata *data;
969 
970 			spin_lock(&domain->lock);
971 			list_for_each_entry(data, &domain->clients, domain_node)
972 				sysmmu_tlb_invalidate_flpdcache(data, iova);
973 			spin_unlock(&domain->lock);
974 		}
975 	}
976 
977 	return page_entry(sent, iova);
978 }
979 
lv1set_section(struct exynos_iommu_domain * domain,sysmmu_pte_t * sent,sysmmu_iova_t iova,phys_addr_t paddr,int prot,short * pgcnt)980 static int lv1set_section(struct exynos_iommu_domain *domain,
981 			  sysmmu_pte_t *sent, sysmmu_iova_t iova,
982 			  phys_addr_t paddr, int prot, short *pgcnt)
983 {
984 	if (lv1ent_section(sent)) {
985 		WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
986 			iova);
987 		return -EADDRINUSE;
988 	}
989 
990 	if (lv1ent_page(sent)) {
991 		if (*pgcnt != NUM_LV2ENTRIES) {
992 			WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
993 				iova);
994 			return -EADDRINUSE;
995 		}
996 
997 		kmem_cache_free(lv2table_kmem_cache, page_entry(sent, 0));
998 		*pgcnt = 0;
999 	}
1000 
1001 	exynos_iommu_set_pte(sent, mk_lv1ent_sect(paddr, prot));
1002 
1003 	spin_lock(&domain->lock);
1004 	if (lv1ent_page_zero(sent)) {
1005 		struct sysmmu_drvdata *data;
1006 		/*
1007 		 * Flushing FLPD cache in System MMU v3.3 that may cache a FLPD
1008 		 * entry by speculative prefetch of SLPD which has no mapping.
1009 		 */
1010 		list_for_each_entry(data, &domain->clients, domain_node)
1011 			sysmmu_tlb_invalidate_flpdcache(data, iova);
1012 	}
1013 	spin_unlock(&domain->lock);
1014 
1015 	return 0;
1016 }
1017 
lv2set_page(sysmmu_pte_t * pent,phys_addr_t paddr,size_t size,int prot,short * pgcnt)1018 static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
1019 		       int prot, short *pgcnt)
1020 {
1021 	if (size == SPAGE_SIZE) {
1022 		if (WARN_ON(!lv2ent_fault(pent)))
1023 			return -EADDRINUSE;
1024 
1025 		exynos_iommu_set_pte(pent, mk_lv2ent_spage(paddr, prot));
1026 		*pgcnt -= 1;
1027 	} else { /* size == LPAGE_SIZE */
1028 		int i;
1029 		dma_addr_t pent_base = virt_to_phys(pent);
1030 
1031 		dma_sync_single_for_cpu(dma_dev, pent_base,
1032 					sizeof(*pent) * SPAGES_PER_LPAGE,
1033 					DMA_TO_DEVICE);
1034 		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
1035 			if (WARN_ON(!lv2ent_fault(pent))) {
1036 				if (i > 0)
1037 					memset(pent - i, 0, sizeof(*pent) * i);
1038 				return -EADDRINUSE;
1039 			}
1040 
1041 			*pent = mk_lv2ent_lpage(paddr, prot);
1042 		}
1043 		dma_sync_single_for_device(dma_dev, pent_base,
1044 					   sizeof(*pent) * SPAGES_PER_LPAGE,
1045 					   DMA_TO_DEVICE);
1046 		*pgcnt -= SPAGES_PER_LPAGE;
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 /*
1053  * *CAUTION* to the I/O virtual memory managers that support exynos-iommu:
1054  *
1055  * System MMU v3.x has advanced logic to improve address translation
1056  * performance with caching more page table entries by a page table walk.
1057  * However, the logic has a bug that while caching faulty page table entries,
1058  * System MMU reports page fault if the cached fault entry is hit even though
1059  * the fault entry is updated to a valid entry after the entry is cached.
1060  * To prevent caching faulty page table entries which may be updated to valid
1061  * entries later, the virtual memory manager should care about the workaround
1062  * for the problem. The following describes the workaround.
1063  *
1064  * Any two consecutive I/O virtual address regions must have a hole of 128KiB
1065  * at maximum to prevent misbehavior of System MMU 3.x (workaround for h/w bug).
1066  *
1067  * Precisely, any start address of I/O virtual region must be aligned with
1068  * the following sizes for System MMU v3.1 and v3.2.
1069  * System MMU v3.1: 128KiB
1070  * System MMU v3.2: 256KiB
1071  *
1072  * Because System MMU v3.3 caches page table entries more aggressively, it needs
1073  * more workarounds.
1074  * - Any two consecutive I/O virtual regions must have a hole of size larger
1075  *   than or equal to 128KiB.
1076  * - Start address of an I/O virtual region must be aligned by 128KiB.
1077  */
exynos_iommu_map(struct iommu_domain * iommu_domain,unsigned long l_iova,phys_addr_t paddr,size_t size,int prot,gfp_t gfp)1078 static int exynos_iommu_map(struct iommu_domain *iommu_domain,
1079 			    unsigned long l_iova, phys_addr_t paddr, size_t size,
1080 			    int prot, gfp_t gfp)
1081 {
1082 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1083 	sysmmu_pte_t *entry;
1084 	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
1085 	unsigned long flags;
1086 	int ret = -ENOMEM;
1087 
1088 	BUG_ON(domain->pgtable == NULL);
1089 	prot &= SYSMMU_SUPPORTED_PROT_BITS;
1090 
1091 	spin_lock_irqsave(&domain->pgtablelock, flags);
1092 
1093 	entry = section_entry(domain->pgtable, iova);
1094 
1095 	if (size == SECT_SIZE) {
1096 		ret = lv1set_section(domain, entry, iova, paddr, prot,
1097 				     &domain->lv2entcnt[lv1ent_offset(iova)]);
1098 	} else {
1099 		sysmmu_pte_t *pent;
1100 
1101 		pent = alloc_lv2entry(domain, entry, iova,
1102 				      &domain->lv2entcnt[lv1ent_offset(iova)]);
1103 
1104 		if (IS_ERR(pent))
1105 			ret = PTR_ERR(pent);
1106 		else
1107 			ret = lv2set_page(pent, paddr, size, prot,
1108 				       &domain->lv2entcnt[lv1ent_offset(iova)]);
1109 	}
1110 
1111 	if (ret)
1112 		pr_err("%s: Failed(%d) to map %#zx bytes @ %#x\n",
1113 			__func__, ret, size, iova);
1114 
1115 	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1116 
1117 	return ret;
1118 }
1119 
exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain * domain,sysmmu_iova_t iova,size_t size)1120 static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *domain,
1121 					      sysmmu_iova_t iova, size_t size)
1122 {
1123 	struct sysmmu_drvdata *data;
1124 	unsigned long flags;
1125 
1126 	spin_lock_irqsave(&domain->lock, flags);
1127 
1128 	list_for_each_entry(data, &domain->clients, domain_node)
1129 		sysmmu_tlb_invalidate_entry(data, iova, size);
1130 
1131 	spin_unlock_irqrestore(&domain->lock, flags);
1132 }
1133 
exynos_iommu_unmap(struct iommu_domain * iommu_domain,unsigned long l_iova,size_t size,struct iommu_iotlb_gather * gather)1134 static size_t exynos_iommu_unmap(struct iommu_domain *iommu_domain,
1135 				 unsigned long l_iova, size_t size,
1136 				 struct iommu_iotlb_gather *gather)
1137 {
1138 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1139 	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
1140 	sysmmu_pte_t *ent;
1141 	size_t err_pgsize;
1142 	unsigned long flags;
1143 
1144 	BUG_ON(domain->pgtable == NULL);
1145 
1146 	spin_lock_irqsave(&domain->pgtablelock, flags);
1147 
1148 	ent = section_entry(domain->pgtable, iova);
1149 
1150 	if (lv1ent_section(ent)) {
1151 		if (WARN_ON(size < SECT_SIZE)) {
1152 			err_pgsize = SECT_SIZE;
1153 			goto err;
1154 		}
1155 
1156 		/* workaround for h/w bug in System MMU v3.3 */
1157 		exynos_iommu_set_pte(ent, ZERO_LV2LINK);
1158 		size = SECT_SIZE;
1159 		goto done;
1160 	}
1161 
1162 	if (unlikely(lv1ent_fault(ent))) {
1163 		if (size > SECT_SIZE)
1164 			size = SECT_SIZE;
1165 		goto done;
1166 	}
1167 
1168 	/* lv1ent_page(sent) == true here */
1169 
1170 	ent = page_entry(ent, iova);
1171 
1172 	if (unlikely(lv2ent_fault(ent))) {
1173 		size = SPAGE_SIZE;
1174 		goto done;
1175 	}
1176 
1177 	if (lv2ent_small(ent)) {
1178 		exynos_iommu_set_pte(ent, 0);
1179 		size = SPAGE_SIZE;
1180 		domain->lv2entcnt[lv1ent_offset(iova)] += 1;
1181 		goto done;
1182 	}
1183 
1184 	/* lv1ent_large(ent) == true here */
1185 	if (WARN_ON(size < LPAGE_SIZE)) {
1186 		err_pgsize = LPAGE_SIZE;
1187 		goto err;
1188 	}
1189 
1190 	dma_sync_single_for_cpu(dma_dev, virt_to_phys(ent),
1191 				sizeof(*ent) * SPAGES_PER_LPAGE,
1192 				DMA_TO_DEVICE);
1193 	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
1194 	dma_sync_single_for_device(dma_dev, virt_to_phys(ent),
1195 				   sizeof(*ent) * SPAGES_PER_LPAGE,
1196 				   DMA_TO_DEVICE);
1197 	size = LPAGE_SIZE;
1198 	domain->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
1199 done:
1200 	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1201 
1202 	exynos_iommu_tlb_invalidate_entry(domain, iova, size);
1203 
1204 	return size;
1205 err:
1206 	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1207 
1208 	pr_err("%s: Failed: size(%#zx) @ %#x is smaller than page size %#zx\n",
1209 		__func__, size, iova, err_pgsize);
1210 
1211 	return 0;
1212 }
1213 
exynos_iommu_iova_to_phys(struct iommu_domain * iommu_domain,dma_addr_t iova)1214 static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
1215 					  dma_addr_t iova)
1216 {
1217 	struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
1218 	sysmmu_pte_t *entry;
1219 	unsigned long flags;
1220 	phys_addr_t phys = 0;
1221 
1222 	spin_lock_irqsave(&domain->pgtablelock, flags);
1223 
1224 	entry = section_entry(domain->pgtable, iova);
1225 
1226 	if (lv1ent_section(entry)) {
1227 		phys = section_phys(entry) + section_offs(iova);
1228 	} else if (lv1ent_page(entry)) {
1229 		entry = page_entry(entry, iova);
1230 
1231 		if (lv2ent_large(entry))
1232 			phys = lpage_phys(entry) + lpage_offs(iova);
1233 		else if (lv2ent_small(entry))
1234 			phys = spage_phys(entry) + spage_offs(iova);
1235 	}
1236 
1237 	spin_unlock_irqrestore(&domain->pgtablelock, flags);
1238 
1239 	return phys;
1240 }
1241 
exynos_iommu_probe_device(struct device * dev)1242 static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
1243 {
1244 	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1245 	struct sysmmu_drvdata *data;
1246 
1247 	if (!has_sysmmu(dev))
1248 		return ERR_PTR(-ENODEV);
1249 
1250 	list_for_each_entry(data, &owner->controllers, owner_node) {
1251 		/*
1252 		 * SYSMMU will be runtime activated via device link
1253 		 * (dependency) to its master device, so there are no
1254 		 * direct calls to pm_runtime_get/put in this driver.
1255 		 */
1256 		data->link = device_link_add(dev, data->sysmmu,
1257 					     DL_FLAG_STATELESS |
1258 					     DL_FLAG_PM_RUNTIME);
1259 	}
1260 
1261 	/* There is always at least one entry, see exynos_iommu_of_xlate() */
1262 	data = list_first_entry(&owner->controllers,
1263 				struct sysmmu_drvdata, owner_node);
1264 
1265 	return &data->iommu;
1266 }
1267 
exynos_iommu_release_device(struct device * dev)1268 static void exynos_iommu_release_device(struct device *dev)
1269 {
1270 	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1271 	struct sysmmu_drvdata *data;
1272 
1273 	if (!has_sysmmu(dev))
1274 		return;
1275 
1276 	if (owner->domain) {
1277 		struct iommu_group *group = iommu_group_get(dev);
1278 
1279 		if (group) {
1280 			WARN_ON(owner->domain !=
1281 				iommu_group_default_domain(group));
1282 			exynos_iommu_detach_device(owner->domain, dev);
1283 			iommu_group_put(group);
1284 		}
1285 	}
1286 
1287 	list_for_each_entry(data, &owner->controllers, owner_node)
1288 		device_link_del(data->link);
1289 }
1290 
exynos_iommu_of_xlate(struct device * dev,struct of_phandle_args * spec)1291 static int exynos_iommu_of_xlate(struct device *dev,
1292 				 struct of_phandle_args *spec)
1293 {
1294 	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
1295 	struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1296 	struct sysmmu_drvdata *data, *entry;
1297 
1298 	if (!sysmmu)
1299 		return -ENODEV;
1300 
1301 	data = platform_get_drvdata(sysmmu);
1302 	if (!data) {
1303 		put_device(&sysmmu->dev);
1304 		return -ENODEV;
1305 	}
1306 
1307 	if (!owner) {
1308 		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
1309 		if (!owner) {
1310 			put_device(&sysmmu->dev);
1311 			return -ENOMEM;
1312 		}
1313 
1314 		INIT_LIST_HEAD(&owner->controllers);
1315 		mutex_init(&owner->rpm_lock);
1316 		dev_iommu_priv_set(dev, owner);
1317 	}
1318 
1319 	list_for_each_entry(entry, &owner->controllers, owner_node)
1320 		if (entry == data)
1321 			return 0;
1322 
1323 	list_add_tail(&data->owner_node, &owner->controllers);
1324 	data->master = dev;
1325 
1326 	return 0;
1327 }
1328 
1329 static const struct iommu_ops exynos_iommu_ops = {
1330 	.domain_alloc = exynos_iommu_domain_alloc,
1331 	.domain_free = exynos_iommu_domain_free,
1332 	.attach_dev = exynos_iommu_attach_device,
1333 	.detach_dev = exynos_iommu_detach_device,
1334 	.map = exynos_iommu_map,
1335 	.unmap = exynos_iommu_unmap,
1336 	.iova_to_phys = exynos_iommu_iova_to_phys,
1337 	.device_group = generic_device_group,
1338 	.probe_device = exynos_iommu_probe_device,
1339 	.release_device = exynos_iommu_release_device,
1340 	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
1341 	.of_xlate = exynos_iommu_of_xlate,
1342 };
1343 
exynos_iommu_init(void)1344 static int __init exynos_iommu_init(void)
1345 {
1346 	struct device_node *np;
1347 	int ret;
1348 
1349 	np = of_find_matching_node(NULL, sysmmu_of_match);
1350 	if (!np)
1351 		return 0;
1352 
1353 	of_node_put(np);
1354 
1355 	lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table",
1356 				LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL);
1357 	if (!lv2table_kmem_cache) {
1358 		pr_err("%s: Failed to create kmem cache\n", __func__);
1359 		return -ENOMEM;
1360 	}
1361 
1362 	ret = platform_driver_register(&exynos_sysmmu_driver);
1363 	if (ret) {
1364 		pr_err("%s: Failed to register driver\n", __func__);
1365 		goto err_reg_driver;
1366 	}
1367 
1368 	zero_lv2_table = kmem_cache_zalloc(lv2table_kmem_cache, GFP_KERNEL);
1369 	if (zero_lv2_table == NULL) {
1370 		pr_err("%s: Failed to allocate zero level2 page table\n",
1371 			__func__);
1372 		ret = -ENOMEM;
1373 		goto err_zero_lv2;
1374 	}
1375 
1376 	ret = bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
1377 	if (ret) {
1378 		pr_err("%s: Failed to register exynos-iommu driver.\n",
1379 								__func__);
1380 		goto err_set_iommu;
1381 	}
1382 
1383 	return 0;
1384 err_set_iommu:
1385 	kmem_cache_free(lv2table_kmem_cache, zero_lv2_table);
1386 err_zero_lv2:
1387 	platform_driver_unregister(&exynos_sysmmu_driver);
1388 err_reg_driver:
1389 	kmem_cache_destroy(lv2table_kmem_cache);
1390 	return ret;
1391 }
1392 core_initcall(exynos_iommu_init);
1393