xref: /openbmc/linux/drivers/iommu/exynos-iommu.c (revision 84d517f3)
1 /* linux/drivers/iommu/exynos_iommu.c
2  *
3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4  *		http://www.samsung.com
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #ifdef CONFIG_EXYNOS_IOMMU_DEBUG
12 #define DEBUG
13 #endif
14 
15 #include <linux/io.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/clk.h>
21 #include <linux/err.h>
22 #include <linux/mm.h>
23 #include <linux/iommu.h>
24 #include <linux/errno.h>
25 #include <linux/list.h>
26 #include <linux/memblock.h>
27 #include <linux/export.h>
28 
29 #include <asm/cacheflush.h>
30 #include <asm/pgtable.h>
31 
32 #include <mach/sysmmu.h>
33 
34 /* We does not consider super section mapping (16MB) */
35 #define SECT_ORDER 20
36 #define LPAGE_ORDER 16
37 #define SPAGE_ORDER 12
38 
39 #define SECT_SIZE (1 << SECT_ORDER)
40 #define LPAGE_SIZE (1 << LPAGE_ORDER)
41 #define SPAGE_SIZE (1 << SPAGE_ORDER)
42 
43 #define SECT_MASK (~(SECT_SIZE - 1))
44 #define LPAGE_MASK (~(LPAGE_SIZE - 1))
45 #define SPAGE_MASK (~(SPAGE_SIZE - 1))
46 
47 #define lv1ent_fault(sent) (((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
48 #define lv1ent_page(sent) ((*(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 #define section_phys(sent) (*(sent) & SECT_MASK)
56 #define section_offs(iova) ((iova) & 0xFFFFF)
57 #define lpage_phys(pent) (*(pent) & LPAGE_MASK)
58 #define lpage_offs(iova) ((iova) & 0xFFFF)
59 #define spage_phys(pent) (*(pent) & SPAGE_MASK)
60 #define spage_offs(iova) ((iova) & 0xFFF)
61 
62 #define lv1ent_offset(iova) ((iova) >> SECT_ORDER)
63 #define lv2ent_offset(iova) (((iova) & 0xFF000) >> SPAGE_ORDER)
64 
65 #define NUM_LV1ENTRIES 4096
66 #define NUM_LV2ENTRIES 256
67 
68 #define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(long))
69 
70 #define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
71 
72 #define lv2table_base(sent) (*(sent) & 0xFFFFFC00)
73 
74 #define mk_lv1ent_sect(pa) ((pa) | 2)
75 #define mk_lv1ent_page(pa) ((pa) | 1)
76 #define mk_lv2ent_lpage(pa) ((pa) | 1)
77 #define mk_lv2ent_spage(pa) ((pa) | 2)
78 
79 #define CTRL_ENABLE	0x5
80 #define CTRL_BLOCK	0x7
81 #define CTRL_DISABLE	0x0
82 
83 #define REG_MMU_CTRL		0x000
84 #define REG_MMU_CFG		0x004
85 #define REG_MMU_STATUS		0x008
86 #define REG_MMU_FLUSH		0x00C
87 #define REG_MMU_FLUSH_ENTRY	0x010
88 #define REG_PT_BASE_ADDR	0x014
89 #define REG_INT_STATUS		0x018
90 #define REG_INT_CLEAR		0x01C
91 
92 #define REG_PAGE_FAULT_ADDR	0x024
93 #define REG_AW_FAULT_ADDR	0x028
94 #define REG_AR_FAULT_ADDR	0x02C
95 #define REG_DEFAULT_SLAVE_ADDR	0x030
96 
97 #define REG_MMU_VERSION		0x034
98 
99 #define REG_PB0_SADDR		0x04C
100 #define REG_PB0_EADDR		0x050
101 #define REG_PB1_SADDR		0x054
102 #define REG_PB1_EADDR		0x058
103 
104 static unsigned long *section_entry(unsigned long *pgtable, unsigned long iova)
105 {
106 	return pgtable + lv1ent_offset(iova);
107 }
108 
109 static unsigned long *page_entry(unsigned long *sent, unsigned long iova)
110 {
111 	return (unsigned long *)__va(lv2table_base(sent)) + lv2ent_offset(iova);
112 }
113 
114 enum exynos_sysmmu_inttype {
115 	SYSMMU_PAGEFAULT,
116 	SYSMMU_AR_MULTIHIT,
117 	SYSMMU_AW_MULTIHIT,
118 	SYSMMU_BUSERROR,
119 	SYSMMU_AR_SECURITY,
120 	SYSMMU_AR_ACCESS,
121 	SYSMMU_AW_SECURITY,
122 	SYSMMU_AW_PROTECTION, /* 7 */
123 	SYSMMU_FAULT_UNKNOWN,
124 	SYSMMU_FAULTS_NUM
125 };
126 
127 /*
128  * @itype: type of fault.
129  * @pgtable_base: the physical address of page table base. This is 0 if @itype
130  *                is SYSMMU_BUSERROR.
131  * @fault_addr: the device (virtual) address that the System MMU tried to
132  *             translated. This is 0 if @itype is SYSMMU_BUSERROR.
133  */
134 typedef int (*sysmmu_fault_handler_t)(enum exynos_sysmmu_inttype itype,
135 			unsigned long pgtable_base, unsigned long fault_addr);
136 
137 static unsigned short fault_reg_offset[SYSMMU_FAULTS_NUM] = {
138 	REG_PAGE_FAULT_ADDR,
139 	REG_AR_FAULT_ADDR,
140 	REG_AW_FAULT_ADDR,
141 	REG_DEFAULT_SLAVE_ADDR,
142 	REG_AR_FAULT_ADDR,
143 	REG_AR_FAULT_ADDR,
144 	REG_AW_FAULT_ADDR,
145 	REG_AW_FAULT_ADDR
146 };
147 
148 static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = {
149 	"PAGE FAULT",
150 	"AR MULTI-HIT FAULT",
151 	"AW MULTI-HIT FAULT",
152 	"BUS ERROR",
153 	"AR SECURITY PROTECTION FAULT",
154 	"AR ACCESS PROTECTION FAULT",
155 	"AW SECURITY PROTECTION FAULT",
156 	"AW ACCESS PROTECTION FAULT",
157 	"UNKNOWN FAULT"
158 };
159 
160 struct exynos_iommu_domain {
161 	struct list_head clients; /* list of sysmmu_drvdata.node */
162 	unsigned long *pgtable; /* lv1 page table, 16KB */
163 	short *lv2entcnt; /* free lv2 entry counter for each section */
164 	spinlock_t lock; /* lock for this structure */
165 	spinlock_t pgtablelock; /* lock for modifying page table @ pgtable */
166 };
167 
168 struct sysmmu_drvdata {
169 	struct list_head node; /* entry of exynos_iommu_domain.clients */
170 	struct device *sysmmu;	/* System MMU's device descriptor */
171 	struct device *dev;	/* Owner of system MMU */
172 	char *dbgname;
173 	int nsfrs;
174 	void __iomem **sfrbases;
175 	struct clk *clk[2];
176 	int activations;
177 	rwlock_t lock;
178 	struct iommu_domain *domain;
179 	sysmmu_fault_handler_t fault_handler;
180 	unsigned long pgtable;
181 };
182 
183 static bool set_sysmmu_active(struct sysmmu_drvdata *data)
184 {
185 	/* return true if the System MMU was not active previously
186 	   and it needs to be initialized */
187 	return ++data->activations == 1;
188 }
189 
190 static bool set_sysmmu_inactive(struct sysmmu_drvdata *data)
191 {
192 	/* return true if the System MMU is needed to be disabled */
193 	BUG_ON(data->activations < 1);
194 	return --data->activations == 0;
195 }
196 
197 static bool is_sysmmu_active(struct sysmmu_drvdata *data)
198 {
199 	return data->activations > 0;
200 }
201 
202 static void sysmmu_unblock(void __iomem *sfrbase)
203 {
204 	__raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
205 }
206 
207 static bool sysmmu_block(void __iomem *sfrbase)
208 {
209 	int i = 120;
210 
211 	__raw_writel(CTRL_BLOCK, sfrbase + REG_MMU_CTRL);
212 	while ((i > 0) && !(__raw_readl(sfrbase + REG_MMU_STATUS) & 1))
213 		--i;
214 
215 	if (!(__raw_readl(sfrbase + REG_MMU_STATUS) & 1)) {
216 		sysmmu_unblock(sfrbase);
217 		return false;
218 	}
219 
220 	return true;
221 }
222 
223 static void __sysmmu_tlb_invalidate(void __iomem *sfrbase)
224 {
225 	__raw_writel(0x1, sfrbase + REG_MMU_FLUSH);
226 }
227 
228 static void __sysmmu_tlb_invalidate_entry(void __iomem *sfrbase,
229 						unsigned long iova)
230 {
231 	__raw_writel((iova & SPAGE_MASK) | 1, sfrbase + REG_MMU_FLUSH_ENTRY);
232 }
233 
234 static void __sysmmu_set_ptbase(void __iomem *sfrbase,
235 				       unsigned long pgd)
236 {
237 	__raw_writel(0x1, sfrbase + REG_MMU_CFG); /* 16KB LV1, LRU */
238 	__raw_writel(pgd, sfrbase + REG_PT_BASE_ADDR);
239 
240 	__sysmmu_tlb_invalidate(sfrbase);
241 }
242 
243 static void __sysmmu_set_prefbuf(void __iomem *sfrbase, unsigned long base,
244 						unsigned long size, int idx)
245 {
246 	__raw_writel(base, sfrbase + REG_PB0_SADDR + idx * 8);
247 	__raw_writel(size - 1 + base,  sfrbase + REG_PB0_EADDR + idx * 8);
248 }
249 
250 static void __set_fault_handler(struct sysmmu_drvdata *data,
251 					sysmmu_fault_handler_t handler)
252 {
253 	unsigned long flags;
254 
255 	write_lock_irqsave(&data->lock, flags);
256 	data->fault_handler = handler;
257 	write_unlock_irqrestore(&data->lock, flags);
258 }
259 
260 void exynos_sysmmu_set_fault_handler(struct device *dev,
261 					sysmmu_fault_handler_t handler)
262 {
263 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
264 
265 	__set_fault_handler(data, handler);
266 }
267 
268 static int default_fault_handler(enum exynos_sysmmu_inttype itype,
269 		     unsigned long pgtable_base, unsigned long fault_addr)
270 {
271 	unsigned long *ent;
272 
273 	if ((itype >= SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
274 		itype = SYSMMU_FAULT_UNKNOWN;
275 
276 	pr_err("%s occurred at 0x%lx(Page table base: 0x%lx)\n",
277 			sysmmu_fault_name[itype], fault_addr, pgtable_base);
278 
279 	ent = section_entry(__va(pgtable_base), fault_addr);
280 	pr_err("\tLv1 entry: 0x%lx\n", *ent);
281 
282 	if (lv1ent_page(ent)) {
283 		ent = page_entry(ent, fault_addr);
284 		pr_err("\t Lv2 entry: 0x%lx\n", *ent);
285 	}
286 
287 	pr_err("Generating Kernel OOPS... because it is unrecoverable.\n");
288 
289 	BUG();
290 
291 	return 0;
292 }
293 
294 static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
295 {
296 	/* SYSMMU is in blocked when interrupt occurred. */
297 	struct sysmmu_drvdata *data = dev_id;
298 	struct resource *irqres;
299 	struct platform_device *pdev;
300 	enum exynos_sysmmu_inttype itype;
301 	unsigned long addr = -1;
302 
303 	int i, ret = -ENOSYS;
304 
305 	read_lock(&data->lock);
306 
307 	WARN_ON(!is_sysmmu_active(data));
308 
309 	pdev = to_platform_device(data->sysmmu);
310 	for (i = 0; i < (pdev->num_resources / 2); i++) {
311 		irqres = platform_get_resource(pdev, IORESOURCE_IRQ, i);
312 		if (irqres && ((int)irqres->start == irq))
313 			break;
314 	}
315 
316 	if (i == pdev->num_resources) {
317 		itype = SYSMMU_FAULT_UNKNOWN;
318 	} else {
319 		itype = (enum exynos_sysmmu_inttype)
320 			__ffs(__raw_readl(data->sfrbases[i] + REG_INT_STATUS));
321 		if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
322 			itype = SYSMMU_FAULT_UNKNOWN;
323 		else
324 			addr = __raw_readl(
325 				data->sfrbases[i] + fault_reg_offset[itype]);
326 	}
327 
328 	if (data->domain)
329 		ret = report_iommu_fault(data->domain, data->dev,
330 				addr, itype);
331 
332 	if ((ret == -ENOSYS) && data->fault_handler) {
333 		unsigned long base = data->pgtable;
334 		if (itype != SYSMMU_FAULT_UNKNOWN)
335 			base = __raw_readl(
336 					data->sfrbases[i] + REG_PT_BASE_ADDR);
337 		ret = data->fault_handler(itype, base, addr);
338 	}
339 
340 	if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
341 		__raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
342 	else
343 		dev_dbg(data->sysmmu, "(%s) %s is not handled.\n",
344 				data->dbgname, sysmmu_fault_name[itype]);
345 
346 	if (itype != SYSMMU_FAULT_UNKNOWN)
347 		sysmmu_unblock(data->sfrbases[i]);
348 
349 	read_unlock(&data->lock);
350 
351 	return IRQ_HANDLED;
352 }
353 
354 static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
355 {
356 	unsigned long flags;
357 	bool disabled = false;
358 	int i;
359 
360 	write_lock_irqsave(&data->lock, flags);
361 
362 	if (!set_sysmmu_inactive(data))
363 		goto finish;
364 
365 	for (i = 0; i < data->nsfrs; i++)
366 		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
367 
368 	if (data->clk[1])
369 		clk_disable(data->clk[1]);
370 	if (data->clk[0])
371 		clk_disable(data->clk[0]);
372 
373 	disabled = true;
374 	data->pgtable = 0;
375 	data->domain = NULL;
376 finish:
377 	write_unlock_irqrestore(&data->lock, flags);
378 
379 	if (disabled)
380 		dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
381 	else
382 		dev_dbg(data->sysmmu, "(%s) %d times left to be disabled\n",
383 					data->dbgname, data->activations);
384 
385 	return disabled;
386 }
387 
388 /* __exynos_sysmmu_enable: Enables System MMU
389  *
390  * returns -error if an error occurred and System MMU is not enabled,
391  * 0 if the System MMU has been just enabled and 1 if System MMU was already
392  * enabled before.
393  */
394 static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
395 			unsigned long pgtable, struct iommu_domain *domain)
396 {
397 	int i, ret = 0;
398 	unsigned long flags;
399 
400 	write_lock_irqsave(&data->lock, flags);
401 
402 	if (!set_sysmmu_active(data)) {
403 		if (WARN_ON(pgtable != data->pgtable)) {
404 			ret = -EBUSY;
405 			set_sysmmu_inactive(data);
406 		} else {
407 			ret = 1;
408 		}
409 
410 		dev_dbg(data->sysmmu, "(%s) Already enabled\n", data->dbgname);
411 		goto finish;
412 	}
413 
414 	if (data->clk[0])
415 		clk_enable(data->clk[0]);
416 	if (data->clk[1])
417 		clk_enable(data->clk[1]);
418 
419 	data->pgtable = pgtable;
420 
421 	for (i = 0; i < data->nsfrs; i++) {
422 		__sysmmu_set_ptbase(data->sfrbases[i], pgtable);
423 
424 		if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
425 			/* System MMU version is 3.x */
426 			__raw_writel((1 << 12) | (2 << 28),
427 					data->sfrbases[i] + REG_MMU_CFG);
428 			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
429 			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
430 		}
431 
432 		__raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
433 	}
434 
435 	data->domain = domain;
436 
437 	dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
438 finish:
439 	write_unlock_irqrestore(&data->lock, flags);
440 
441 	return ret;
442 }
443 
444 int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
445 {
446 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
447 	int ret;
448 
449 	BUG_ON(!memblock_is_memory(pgtable));
450 
451 	ret = pm_runtime_get_sync(data->sysmmu);
452 	if (ret < 0) {
453 		dev_dbg(data->sysmmu, "(%s) Failed to enable\n", data->dbgname);
454 		return ret;
455 	}
456 
457 	ret = __exynos_sysmmu_enable(data, pgtable, NULL);
458 	if (WARN_ON(ret < 0)) {
459 		pm_runtime_put(data->sysmmu);
460 		dev_err(data->sysmmu,
461 			"(%s) Already enabled with page table %#lx\n",
462 			data->dbgname, data->pgtable);
463 	} else {
464 		data->dev = dev;
465 	}
466 
467 	return ret;
468 }
469 
470 static bool exynos_sysmmu_disable(struct device *dev)
471 {
472 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
473 	bool disabled;
474 
475 	disabled = __exynos_sysmmu_disable(data);
476 	pm_runtime_put(data->sysmmu);
477 
478 	return disabled;
479 }
480 
481 static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
482 {
483 	unsigned long flags;
484 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
485 
486 	read_lock_irqsave(&data->lock, flags);
487 
488 	if (is_sysmmu_active(data)) {
489 		int i;
490 		for (i = 0; i < data->nsfrs; i++) {
491 			if (sysmmu_block(data->sfrbases[i])) {
492 				__sysmmu_tlb_invalidate_entry(
493 						data->sfrbases[i], iova);
494 				sysmmu_unblock(data->sfrbases[i]);
495 			}
496 		}
497 	} else {
498 		dev_dbg(data->sysmmu,
499 			"(%s) Disabled. Skipping invalidating TLB.\n",
500 			data->dbgname);
501 	}
502 
503 	read_unlock_irqrestore(&data->lock, flags);
504 }
505 
506 void exynos_sysmmu_tlb_invalidate(struct device *dev)
507 {
508 	unsigned long flags;
509 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
510 
511 	read_lock_irqsave(&data->lock, flags);
512 
513 	if (is_sysmmu_active(data)) {
514 		int i;
515 		for (i = 0; i < data->nsfrs; i++) {
516 			if (sysmmu_block(data->sfrbases[i])) {
517 				__sysmmu_tlb_invalidate(data->sfrbases[i]);
518 				sysmmu_unblock(data->sfrbases[i]);
519 			}
520 		}
521 	} else {
522 		dev_dbg(data->sysmmu,
523 			"(%s) Disabled. Skipping invalidating TLB.\n",
524 			data->dbgname);
525 	}
526 
527 	read_unlock_irqrestore(&data->lock, flags);
528 }
529 
530 static int exynos_sysmmu_probe(struct platform_device *pdev)
531 {
532 	int i, ret;
533 	struct device *dev;
534 	struct sysmmu_drvdata *data;
535 
536 	dev = &pdev->dev;
537 
538 	data = kzalloc(sizeof(*data), GFP_KERNEL);
539 	if (!data) {
540 		dev_dbg(dev, "Not enough memory\n");
541 		ret = -ENOMEM;
542 		goto err_alloc;
543 	}
544 
545 	dev_set_drvdata(dev, data);
546 	data->nsfrs = pdev->num_resources / 2;
547 	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
548 								GFP_KERNEL);
549 	if (data->sfrbases == NULL) {
550 		dev_dbg(dev, "Not enough memory\n");
551 		ret = -ENOMEM;
552 		goto err_init;
553 	}
554 
555 	for (i = 0; i < data->nsfrs; i++) {
556 		struct resource *res;
557 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
558 		if (!res) {
559 			dev_dbg(dev, "Unable to find IOMEM region\n");
560 			ret = -ENOENT;
561 			goto err_res;
562 		}
563 
564 		data->sfrbases[i] = ioremap(res->start, resource_size(res));
565 		if (!data->sfrbases[i]) {
566 			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
567 							res->start);
568 			ret = -ENOENT;
569 			goto err_res;
570 		}
571 	}
572 
573 	for (i = 0; i < data->nsfrs; i++) {
574 		ret = platform_get_irq(pdev, i);
575 		if (ret <= 0) {
576 			dev_dbg(dev, "Unable to find IRQ resource\n");
577 			goto err_irq;
578 		}
579 
580 		ret = request_irq(ret, exynos_sysmmu_irq, 0,
581 					dev_name(dev), data);
582 		if (ret) {
583 			dev_dbg(dev, "Unabled to register interrupt handler\n");
584 			goto err_irq;
585 		}
586 	}
587 
588 	if (dev_get_platdata(dev)) {
589 		char *deli, *beg;
590 		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
591 
592 		beg = platdata->clockname;
593 
594 		for (deli = beg; (*deli != '\0') && (*deli != ','); deli++)
595 			/* NOTHING */;
596 
597 		if (*deli == '\0')
598 			deli = NULL;
599 		else
600 			*deli = '\0';
601 
602 		data->clk[0] = clk_get(dev, beg);
603 		if (IS_ERR(data->clk[0])) {
604 			data->clk[0] = NULL;
605 			dev_dbg(dev, "No clock descriptor registered\n");
606 		}
607 
608 		if (data->clk[0] && deli) {
609 			*deli = ',';
610 			data->clk[1] = clk_get(dev, deli + 1);
611 			if (IS_ERR(data->clk[1]))
612 				data->clk[1] = NULL;
613 		}
614 
615 		data->dbgname = platdata->dbgname;
616 	}
617 
618 	data->sysmmu = dev;
619 	rwlock_init(&data->lock);
620 	INIT_LIST_HEAD(&data->node);
621 
622 	__set_fault_handler(data, &default_fault_handler);
623 
624 	if (dev->parent)
625 		pm_runtime_enable(dev);
626 
627 	dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
628 	return 0;
629 err_irq:
630 	while (i-- > 0) {
631 		int irq;
632 
633 		irq = platform_get_irq(pdev, i);
634 		free_irq(irq, data);
635 	}
636 err_res:
637 	while (data->nsfrs-- > 0)
638 		iounmap(data->sfrbases[data->nsfrs]);
639 	kfree(data->sfrbases);
640 err_init:
641 	kfree(data);
642 err_alloc:
643 	dev_err(dev, "Failed to initialize\n");
644 	return ret;
645 }
646 
647 static struct platform_driver exynos_sysmmu_driver = {
648 	.probe		= exynos_sysmmu_probe,
649 	.driver		= {
650 		.owner		= THIS_MODULE,
651 		.name		= "exynos-sysmmu",
652 	}
653 };
654 
655 static inline void pgtable_flush(void *vastart, void *vaend)
656 {
657 	dmac_flush_range(vastart, vaend);
658 	outer_flush_range(virt_to_phys(vastart),
659 				virt_to_phys(vaend));
660 }
661 
662 static int exynos_iommu_domain_init(struct iommu_domain *domain)
663 {
664 	struct exynos_iommu_domain *priv;
665 
666 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
667 	if (!priv)
668 		return -ENOMEM;
669 
670 	priv->pgtable = (unsigned long *)__get_free_pages(
671 						GFP_KERNEL | __GFP_ZERO, 2);
672 	if (!priv->pgtable)
673 		goto err_pgtable;
674 
675 	priv->lv2entcnt = (short *)__get_free_pages(
676 						GFP_KERNEL | __GFP_ZERO, 1);
677 	if (!priv->lv2entcnt)
678 		goto err_counter;
679 
680 	pgtable_flush(priv->pgtable, priv->pgtable + NUM_LV1ENTRIES);
681 
682 	spin_lock_init(&priv->lock);
683 	spin_lock_init(&priv->pgtablelock);
684 	INIT_LIST_HEAD(&priv->clients);
685 
686 	domain->geometry.aperture_start = 0;
687 	domain->geometry.aperture_end   = ~0UL;
688 	domain->geometry.force_aperture = true;
689 
690 	domain->priv = priv;
691 	return 0;
692 
693 err_counter:
694 	free_pages((unsigned long)priv->pgtable, 2);
695 err_pgtable:
696 	kfree(priv);
697 	return -ENOMEM;
698 }
699 
700 static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
701 {
702 	struct exynos_iommu_domain *priv = domain->priv;
703 	struct sysmmu_drvdata *data;
704 	unsigned long flags;
705 	int i;
706 
707 	WARN_ON(!list_empty(&priv->clients));
708 
709 	spin_lock_irqsave(&priv->lock, flags);
710 
711 	list_for_each_entry(data, &priv->clients, node) {
712 		while (!exynos_sysmmu_disable(data->dev))
713 			; /* until System MMU is actually disabled */
714 	}
715 
716 	spin_unlock_irqrestore(&priv->lock, flags);
717 
718 	for (i = 0; i < NUM_LV1ENTRIES; i++)
719 		if (lv1ent_page(priv->pgtable + i))
720 			kfree(__va(lv2table_base(priv->pgtable + i)));
721 
722 	free_pages((unsigned long)priv->pgtable, 2);
723 	free_pages((unsigned long)priv->lv2entcnt, 1);
724 	kfree(domain->priv);
725 	domain->priv = NULL;
726 }
727 
728 static int exynos_iommu_attach_device(struct iommu_domain *domain,
729 				   struct device *dev)
730 {
731 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
732 	struct exynos_iommu_domain *priv = domain->priv;
733 	unsigned long flags;
734 	int ret;
735 
736 	ret = pm_runtime_get_sync(data->sysmmu);
737 	if (ret < 0)
738 		return ret;
739 
740 	ret = 0;
741 
742 	spin_lock_irqsave(&priv->lock, flags);
743 
744 	ret = __exynos_sysmmu_enable(data, __pa(priv->pgtable), domain);
745 
746 	if (ret == 0) {
747 		/* 'data->node' must not be appeared in priv->clients */
748 		BUG_ON(!list_empty(&data->node));
749 		data->dev = dev;
750 		list_add_tail(&data->node, &priv->clients);
751 	}
752 
753 	spin_unlock_irqrestore(&priv->lock, flags);
754 
755 	if (ret < 0) {
756 		dev_err(dev, "%s: Failed to attach IOMMU with pgtable %#lx\n",
757 				__func__, __pa(priv->pgtable));
758 		pm_runtime_put(data->sysmmu);
759 	} else if (ret > 0) {
760 		dev_dbg(dev, "%s: IOMMU with pgtable 0x%lx already attached\n",
761 					__func__, __pa(priv->pgtable));
762 	} else {
763 		dev_dbg(dev, "%s: Attached new IOMMU with pgtable 0x%lx\n",
764 					__func__, __pa(priv->pgtable));
765 	}
766 
767 	return ret;
768 }
769 
770 static void exynos_iommu_detach_device(struct iommu_domain *domain,
771 				    struct device *dev)
772 {
773 	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
774 	struct exynos_iommu_domain *priv = domain->priv;
775 	struct list_head *pos;
776 	unsigned long flags;
777 	bool found = false;
778 
779 	spin_lock_irqsave(&priv->lock, flags);
780 
781 	list_for_each(pos, &priv->clients) {
782 		if (list_entry(pos, struct sysmmu_drvdata, node) == data) {
783 			found = true;
784 			break;
785 		}
786 	}
787 
788 	if (!found)
789 		goto finish;
790 
791 	if (__exynos_sysmmu_disable(data)) {
792 		dev_dbg(dev, "%s: Detached IOMMU with pgtable %#lx\n",
793 					__func__, __pa(priv->pgtable));
794 		list_del_init(&data->node);
795 
796 	} else {
797 		dev_dbg(dev, "%s: Detaching IOMMU with pgtable %#lx delayed",
798 					__func__, __pa(priv->pgtable));
799 	}
800 
801 finish:
802 	spin_unlock_irqrestore(&priv->lock, flags);
803 
804 	if (found)
805 		pm_runtime_put(data->sysmmu);
806 }
807 
808 static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
809 					short *pgcounter)
810 {
811 	if (lv1ent_fault(sent)) {
812 		unsigned long *pent;
813 
814 		pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC);
815 		BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
816 		if (!pent)
817 			return NULL;
818 
819 		*sent = mk_lv1ent_page(__pa(pent));
820 		*pgcounter = NUM_LV2ENTRIES;
821 		pgtable_flush(pent, pent + NUM_LV2ENTRIES);
822 		pgtable_flush(sent, sent + 1);
823 	}
824 
825 	return page_entry(sent, iova);
826 }
827 
828 static int lv1set_section(unsigned long *sent, phys_addr_t paddr, short *pgcnt)
829 {
830 	if (lv1ent_section(sent))
831 		return -EADDRINUSE;
832 
833 	if (lv1ent_page(sent)) {
834 		if (*pgcnt != NUM_LV2ENTRIES)
835 			return -EADDRINUSE;
836 
837 		kfree(page_entry(sent, 0));
838 
839 		*pgcnt = 0;
840 	}
841 
842 	*sent = mk_lv1ent_sect(paddr);
843 
844 	pgtable_flush(sent, sent + 1);
845 
846 	return 0;
847 }
848 
849 static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t size,
850 								short *pgcnt)
851 {
852 	if (size == SPAGE_SIZE) {
853 		if (!lv2ent_fault(pent))
854 			return -EADDRINUSE;
855 
856 		*pent = mk_lv2ent_spage(paddr);
857 		pgtable_flush(pent, pent + 1);
858 		*pgcnt -= 1;
859 	} else { /* size == LPAGE_SIZE */
860 		int i;
861 		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
862 			if (!lv2ent_fault(pent)) {
863 				memset(pent, 0, sizeof(*pent) * i);
864 				return -EADDRINUSE;
865 			}
866 
867 			*pent = mk_lv2ent_lpage(paddr);
868 		}
869 		pgtable_flush(pent - SPAGES_PER_LPAGE, pent);
870 		*pgcnt -= SPAGES_PER_LPAGE;
871 	}
872 
873 	return 0;
874 }
875 
876 static int exynos_iommu_map(struct iommu_domain *domain, unsigned long iova,
877 			 phys_addr_t paddr, size_t size, int prot)
878 {
879 	struct exynos_iommu_domain *priv = domain->priv;
880 	unsigned long *entry;
881 	unsigned long flags;
882 	int ret = -ENOMEM;
883 
884 	BUG_ON(priv->pgtable == NULL);
885 
886 	spin_lock_irqsave(&priv->pgtablelock, flags);
887 
888 	entry = section_entry(priv->pgtable, iova);
889 
890 	if (size == SECT_SIZE) {
891 		ret = lv1set_section(entry, paddr,
892 					&priv->lv2entcnt[lv1ent_offset(iova)]);
893 	} else {
894 		unsigned long *pent;
895 
896 		pent = alloc_lv2entry(entry, iova,
897 					&priv->lv2entcnt[lv1ent_offset(iova)]);
898 
899 		if (!pent)
900 			ret = -ENOMEM;
901 		else
902 			ret = lv2set_page(pent, paddr, size,
903 					&priv->lv2entcnt[lv1ent_offset(iova)]);
904 	}
905 
906 	if (ret) {
907 		pr_debug("%s: Failed to map iova 0x%lx/0x%x bytes\n",
908 							__func__, iova, size);
909 	}
910 
911 	spin_unlock_irqrestore(&priv->pgtablelock, flags);
912 
913 	return ret;
914 }
915 
916 static size_t exynos_iommu_unmap(struct iommu_domain *domain,
917 					       unsigned long iova, size_t size)
918 {
919 	struct exynos_iommu_domain *priv = domain->priv;
920 	struct sysmmu_drvdata *data;
921 	unsigned long flags;
922 	unsigned long *ent;
923 
924 	BUG_ON(priv->pgtable == NULL);
925 
926 	spin_lock_irqsave(&priv->pgtablelock, flags);
927 
928 	ent = section_entry(priv->pgtable, iova);
929 
930 	if (lv1ent_section(ent)) {
931 		BUG_ON(size < SECT_SIZE);
932 
933 		*ent = 0;
934 		pgtable_flush(ent, ent + 1);
935 		size = SECT_SIZE;
936 		goto done;
937 	}
938 
939 	if (unlikely(lv1ent_fault(ent))) {
940 		if (size > SECT_SIZE)
941 			size = SECT_SIZE;
942 		goto done;
943 	}
944 
945 	/* lv1ent_page(sent) == true here */
946 
947 	ent = page_entry(ent, iova);
948 
949 	if (unlikely(lv2ent_fault(ent))) {
950 		size = SPAGE_SIZE;
951 		goto done;
952 	}
953 
954 	if (lv2ent_small(ent)) {
955 		*ent = 0;
956 		size = SPAGE_SIZE;
957 		priv->lv2entcnt[lv1ent_offset(iova)] += 1;
958 		goto done;
959 	}
960 
961 	/* lv1ent_large(ent) == true here */
962 	BUG_ON(size < LPAGE_SIZE);
963 
964 	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
965 
966 	size = LPAGE_SIZE;
967 	priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
968 done:
969 	spin_unlock_irqrestore(&priv->pgtablelock, flags);
970 
971 	spin_lock_irqsave(&priv->lock, flags);
972 	list_for_each_entry(data, &priv->clients, node)
973 		sysmmu_tlb_invalidate_entry(data->dev, iova);
974 	spin_unlock_irqrestore(&priv->lock, flags);
975 
976 
977 	return size;
978 }
979 
980 static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
981 					  dma_addr_t iova)
982 {
983 	struct exynos_iommu_domain *priv = domain->priv;
984 	unsigned long *entry;
985 	unsigned long flags;
986 	phys_addr_t phys = 0;
987 
988 	spin_lock_irqsave(&priv->pgtablelock, flags);
989 
990 	entry = section_entry(priv->pgtable, iova);
991 
992 	if (lv1ent_section(entry)) {
993 		phys = section_phys(entry) + section_offs(iova);
994 	} else if (lv1ent_page(entry)) {
995 		entry = page_entry(entry, iova);
996 
997 		if (lv2ent_large(entry))
998 			phys = lpage_phys(entry) + lpage_offs(iova);
999 		else if (lv2ent_small(entry))
1000 			phys = spage_phys(entry) + spage_offs(iova);
1001 	}
1002 
1003 	spin_unlock_irqrestore(&priv->pgtablelock, flags);
1004 
1005 	return phys;
1006 }
1007 
1008 static struct iommu_ops exynos_iommu_ops = {
1009 	.domain_init = exynos_iommu_domain_init,
1010 	.domain_destroy = exynos_iommu_domain_destroy,
1011 	.attach_dev = exynos_iommu_attach_device,
1012 	.detach_dev = exynos_iommu_detach_device,
1013 	.map = exynos_iommu_map,
1014 	.unmap = exynos_iommu_unmap,
1015 	.iova_to_phys = exynos_iommu_iova_to_phys,
1016 	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
1017 };
1018 
1019 static int __init exynos_iommu_init(void)
1020 {
1021 	int ret;
1022 
1023 	ret = platform_driver_register(&exynos_sysmmu_driver);
1024 
1025 	if (ret == 0)
1026 		bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
1027 
1028 	return ret;
1029 }
1030 subsys_initcall(exynos_iommu_init);
1031