xref: /openbmc/linux/drivers/iommu/omap-iommu.c (revision eb3fcf00)
1 /*
2  * omap iommu: tlb and pagetable primitives
3  *
4  * Copyright (C) 2008-2010 Nokia Corporation
5  *
6  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
7  *		Paul Mundt and Toshihiro Kobayashi
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/interrupt.h>
17 #include <linux/ioport.h>
18 #include <linux/platform_device.h>
19 #include <linux/iommu.h>
20 #include <linux/omap-iommu.h>
21 #include <linux/mutex.h>
22 #include <linux/spinlock.h>
23 #include <linux/io.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/of.h>
26 #include <linux/of_iommu.h>
27 #include <linux/of_irq.h>
28 #include <linux/of_platform.h>
29 
30 #include <asm/cacheflush.h>
31 
32 #include <linux/platform_data/iommu-omap.h>
33 
34 #include "omap-iopgtable.h"
35 #include "omap-iommu.h"
36 
37 #define to_iommu(dev)							\
38 	((struct omap_iommu *)platform_get_drvdata(to_platform_device(dev)))
39 
40 /* bitmap of the page sizes currently supported */
41 #define OMAP_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
42 
43 /**
44  * struct omap_iommu_domain - omap iommu domain
45  * @pgtable:	the page table
46  * @iommu_dev:	an omap iommu device attached to this domain. only a single
47  *		iommu device can be attached for now.
48  * @dev:	Device using this domain.
49  * @lock:	domain lock, should be taken when attaching/detaching
50  */
51 struct omap_iommu_domain {
52 	u32 *pgtable;
53 	struct omap_iommu *iommu_dev;
54 	struct device *dev;
55 	spinlock_t lock;
56 	struct iommu_domain domain;
57 };
58 
59 #define MMU_LOCK_BASE_SHIFT	10
60 #define MMU_LOCK_BASE_MASK	(0x1f << MMU_LOCK_BASE_SHIFT)
61 #define MMU_LOCK_BASE(x)	\
62 	((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
63 
64 #define MMU_LOCK_VICT_SHIFT	4
65 #define MMU_LOCK_VICT_MASK	(0x1f << MMU_LOCK_VICT_SHIFT)
66 #define MMU_LOCK_VICT(x)	\
67 	((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
68 
69 static struct platform_driver omap_iommu_driver;
70 static struct kmem_cache *iopte_cachep;
71 
72 /**
73  * to_omap_domain - Get struct omap_iommu_domain from generic iommu_domain
74  * @dom:	generic iommu domain handle
75  **/
76 static struct omap_iommu_domain *to_omap_domain(struct iommu_domain *dom)
77 {
78 	return container_of(dom, struct omap_iommu_domain, domain);
79 }
80 
81 /**
82  * omap_iommu_save_ctx - Save registers for pm off-mode support
83  * @dev:	client device
84  **/
85 void omap_iommu_save_ctx(struct device *dev)
86 {
87 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
88 	u32 *p = obj->ctx;
89 	int i;
90 
91 	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
92 		p[i] = iommu_read_reg(obj, i * sizeof(u32));
93 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
94 	}
95 }
96 EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
97 
98 /**
99  * omap_iommu_restore_ctx - Restore registers for pm off-mode support
100  * @dev:	client device
101  **/
102 void omap_iommu_restore_ctx(struct device *dev)
103 {
104 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
105 	u32 *p = obj->ctx;
106 	int i;
107 
108 	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
109 		iommu_write_reg(obj, p[i], i * sizeof(u32));
110 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
111 	}
112 }
113 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
114 
115 static void __iommu_set_twl(struct omap_iommu *obj, bool on)
116 {
117 	u32 l = iommu_read_reg(obj, MMU_CNTL);
118 
119 	if (on)
120 		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
121 	else
122 		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
123 
124 	l &= ~MMU_CNTL_MASK;
125 	if (on)
126 		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
127 	else
128 		l |= (MMU_CNTL_MMU_EN);
129 
130 	iommu_write_reg(obj, l, MMU_CNTL);
131 }
132 
133 static int omap2_iommu_enable(struct omap_iommu *obj)
134 {
135 	u32 l, pa;
136 
137 	if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
138 		return -EINVAL;
139 
140 	pa = virt_to_phys(obj->iopgd);
141 	if (!IS_ALIGNED(pa, SZ_16K))
142 		return -EINVAL;
143 
144 	l = iommu_read_reg(obj, MMU_REVISION);
145 	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
146 		 (l >> 4) & 0xf, l & 0xf);
147 
148 	iommu_write_reg(obj, pa, MMU_TTB);
149 
150 	if (obj->has_bus_err_back)
151 		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
152 
153 	__iommu_set_twl(obj, true);
154 
155 	return 0;
156 }
157 
158 static void omap2_iommu_disable(struct omap_iommu *obj)
159 {
160 	u32 l = iommu_read_reg(obj, MMU_CNTL);
161 
162 	l &= ~MMU_CNTL_MASK;
163 	iommu_write_reg(obj, l, MMU_CNTL);
164 
165 	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
166 }
167 
168 static int iommu_enable(struct omap_iommu *obj)
169 {
170 	int err;
171 	struct platform_device *pdev = to_platform_device(obj->dev);
172 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
173 
174 	if (pdata && pdata->deassert_reset) {
175 		err = pdata->deassert_reset(pdev, pdata->reset_name);
176 		if (err) {
177 			dev_err(obj->dev, "deassert_reset failed: %d\n", err);
178 			return err;
179 		}
180 	}
181 
182 	pm_runtime_get_sync(obj->dev);
183 
184 	err = omap2_iommu_enable(obj);
185 
186 	return err;
187 }
188 
189 static void iommu_disable(struct omap_iommu *obj)
190 {
191 	struct platform_device *pdev = to_platform_device(obj->dev);
192 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
193 
194 	omap2_iommu_disable(obj);
195 
196 	pm_runtime_put_sync(obj->dev);
197 
198 	if (pdata && pdata->assert_reset)
199 		pdata->assert_reset(pdev, pdata->reset_name);
200 }
201 
202 /*
203  *	TLB operations
204  */
205 static u32 iotlb_cr_to_virt(struct cr_regs *cr)
206 {
207 	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
208 	u32 mask = get_cam_va_mask(cr->cam & page_size);
209 
210 	return cr->cam & mask;
211 }
212 
213 static u32 get_iopte_attr(struct iotlb_entry *e)
214 {
215 	u32 attr;
216 
217 	attr = e->mixed << 5;
218 	attr |= e->endian;
219 	attr |= e->elsz >> 3;
220 	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
221 			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
222 	return attr;
223 }
224 
225 static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
226 {
227 	u32 status, fault_addr;
228 
229 	status = iommu_read_reg(obj, MMU_IRQSTATUS);
230 	status &= MMU_IRQ_MASK;
231 	if (!status) {
232 		*da = 0;
233 		return 0;
234 	}
235 
236 	fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
237 	*da = fault_addr;
238 
239 	iommu_write_reg(obj, status, MMU_IRQSTATUS);
240 
241 	return status;
242 }
243 
244 void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
245 {
246 	u32 val;
247 
248 	val = iommu_read_reg(obj, MMU_LOCK);
249 
250 	l->base = MMU_LOCK_BASE(val);
251 	l->vict = MMU_LOCK_VICT(val);
252 }
253 
254 void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
255 {
256 	u32 val;
257 
258 	val = (l->base << MMU_LOCK_BASE_SHIFT);
259 	val |= (l->vict << MMU_LOCK_VICT_SHIFT);
260 
261 	iommu_write_reg(obj, val, MMU_LOCK);
262 }
263 
264 static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
265 {
266 	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
267 	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
268 }
269 
270 static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
271 {
272 	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
273 	iommu_write_reg(obj, cr->ram, MMU_RAM);
274 
275 	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
276 	iommu_write_reg(obj, 1, MMU_LD_TLB);
277 }
278 
279 /* only used in iotlb iteration for-loop */
280 struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
281 {
282 	struct cr_regs cr;
283 	struct iotlb_lock l;
284 
285 	iotlb_lock_get(obj, &l);
286 	l.vict = n;
287 	iotlb_lock_set(obj, &l);
288 	iotlb_read_cr(obj, &cr);
289 
290 	return cr;
291 }
292 
293 #ifdef PREFETCH_IOTLB
294 static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
295 				      struct iotlb_entry *e)
296 {
297 	struct cr_regs *cr;
298 
299 	if (!e)
300 		return NULL;
301 
302 	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
303 		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
304 			e->da);
305 		return ERR_PTR(-EINVAL);
306 	}
307 
308 	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
309 	if (!cr)
310 		return ERR_PTR(-ENOMEM);
311 
312 	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
313 	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
314 
315 	return cr;
316 }
317 
318 /**
319  * load_iotlb_entry - Set an iommu tlb entry
320  * @obj:	target iommu
321  * @e:		an iommu tlb entry info
322  **/
323 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
324 {
325 	int err = 0;
326 	struct iotlb_lock l;
327 	struct cr_regs *cr;
328 
329 	if (!obj || !obj->nr_tlb_entries || !e)
330 		return -EINVAL;
331 
332 	pm_runtime_get_sync(obj->dev);
333 
334 	iotlb_lock_get(obj, &l);
335 	if (l.base == obj->nr_tlb_entries) {
336 		dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
337 		err = -EBUSY;
338 		goto out;
339 	}
340 	if (!e->prsvd) {
341 		int i;
342 		struct cr_regs tmp;
343 
344 		for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
345 			if (!iotlb_cr_valid(&tmp))
346 				break;
347 
348 		if (i == obj->nr_tlb_entries) {
349 			dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
350 			err = -EBUSY;
351 			goto out;
352 		}
353 
354 		iotlb_lock_get(obj, &l);
355 	} else {
356 		l.vict = l.base;
357 		iotlb_lock_set(obj, &l);
358 	}
359 
360 	cr = iotlb_alloc_cr(obj, e);
361 	if (IS_ERR(cr)) {
362 		pm_runtime_put_sync(obj->dev);
363 		return PTR_ERR(cr);
364 	}
365 
366 	iotlb_load_cr(obj, cr);
367 	kfree(cr);
368 
369 	if (e->prsvd)
370 		l.base++;
371 	/* increment victim for next tlb load */
372 	if (++l.vict == obj->nr_tlb_entries)
373 		l.vict = l.base;
374 	iotlb_lock_set(obj, &l);
375 out:
376 	pm_runtime_put_sync(obj->dev);
377 	return err;
378 }
379 
380 #else /* !PREFETCH_IOTLB */
381 
382 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
383 {
384 	return 0;
385 }
386 
387 #endif /* !PREFETCH_IOTLB */
388 
389 static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
390 {
391 	return load_iotlb_entry(obj, e);
392 }
393 
394 /**
395  * flush_iotlb_page - Clear an iommu tlb entry
396  * @obj:	target iommu
397  * @da:		iommu device virtual address
398  *
399  * Clear an iommu tlb entry which includes 'da' address.
400  **/
401 static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
402 {
403 	int i;
404 	struct cr_regs cr;
405 
406 	pm_runtime_get_sync(obj->dev);
407 
408 	for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
409 		u32 start;
410 		size_t bytes;
411 
412 		if (!iotlb_cr_valid(&cr))
413 			continue;
414 
415 		start = iotlb_cr_to_virt(&cr);
416 		bytes = iopgsz_to_bytes(cr.cam & 3);
417 
418 		if ((start <= da) && (da < start + bytes)) {
419 			dev_dbg(obj->dev, "%s: %08x<=%08x(%x)\n",
420 				__func__, start, da, bytes);
421 			iotlb_load_cr(obj, &cr);
422 			iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
423 			break;
424 		}
425 	}
426 	pm_runtime_put_sync(obj->dev);
427 
428 	if (i == obj->nr_tlb_entries)
429 		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
430 }
431 
432 /**
433  * flush_iotlb_all - Clear all iommu tlb entries
434  * @obj:	target iommu
435  **/
436 static void flush_iotlb_all(struct omap_iommu *obj)
437 {
438 	struct iotlb_lock l;
439 
440 	pm_runtime_get_sync(obj->dev);
441 
442 	l.base = 0;
443 	l.vict = 0;
444 	iotlb_lock_set(obj, &l);
445 
446 	iommu_write_reg(obj, 1, MMU_GFLUSH);
447 
448 	pm_runtime_put_sync(obj->dev);
449 }
450 
451 /*
452  *	H/W pagetable operations
453  */
454 static void flush_iopgd_range(u32 *first, u32 *last)
455 {
456 	/* FIXME: L2 cache should be taken care of if it exists */
457 	do {
458 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pgd"
459 		    : : "r" (first));
460 		first += L1_CACHE_BYTES / sizeof(*first);
461 	} while (first <= last);
462 }
463 
464 static void flush_iopte_range(u32 *first, u32 *last)
465 {
466 	/* FIXME: L2 cache should be taken care of if it exists */
467 	do {
468 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pte"
469 		    : : "r" (first));
470 		first += L1_CACHE_BYTES / sizeof(*first);
471 	} while (first <= last);
472 }
473 
474 static void iopte_free(u32 *iopte)
475 {
476 	/* Note: freed iopte's must be clean ready for re-use */
477 	if (iopte)
478 		kmem_cache_free(iopte_cachep, iopte);
479 }
480 
481 static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd, u32 da)
482 {
483 	u32 *iopte;
484 
485 	/* a table has already existed */
486 	if (*iopgd)
487 		goto pte_ready;
488 
489 	/*
490 	 * do the allocation outside the page table lock
491 	 */
492 	spin_unlock(&obj->page_table_lock);
493 	iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
494 	spin_lock(&obj->page_table_lock);
495 
496 	if (!*iopgd) {
497 		if (!iopte)
498 			return ERR_PTR(-ENOMEM);
499 
500 		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
501 		flush_iopgd_range(iopgd, iopgd);
502 
503 		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
504 	} else {
505 		/* We raced, free the reduniovant table */
506 		iopte_free(iopte);
507 	}
508 
509 pte_ready:
510 	iopte = iopte_offset(iopgd, da);
511 
512 	dev_vdbg(obj->dev,
513 		 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
514 		 __func__, da, iopgd, *iopgd, iopte, *iopte);
515 
516 	return iopte;
517 }
518 
519 static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
520 {
521 	u32 *iopgd = iopgd_offset(obj, da);
522 
523 	if ((da | pa) & ~IOSECTION_MASK) {
524 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
525 			__func__, da, pa, IOSECTION_SIZE);
526 		return -EINVAL;
527 	}
528 
529 	*iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
530 	flush_iopgd_range(iopgd, iopgd);
531 	return 0;
532 }
533 
534 static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
535 {
536 	u32 *iopgd = iopgd_offset(obj, da);
537 	int i;
538 
539 	if ((da | pa) & ~IOSUPER_MASK) {
540 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
541 			__func__, da, pa, IOSUPER_SIZE);
542 		return -EINVAL;
543 	}
544 
545 	for (i = 0; i < 16; i++)
546 		*(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
547 	flush_iopgd_range(iopgd, iopgd + 15);
548 	return 0;
549 }
550 
551 static int iopte_alloc_page(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
552 {
553 	u32 *iopgd = iopgd_offset(obj, da);
554 	u32 *iopte = iopte_alloc(obj, iopgd, da);
555 
556 	if (IS_ERR(iopte))
557 		return PTR_ERR(iopte);
558 
559 	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
560 	flush_iopte_range(iopte, iopte);
561 
562 	dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
563 		 __func__, da, pa, iopte, *iopte);
564 
565 	return 0;
566 }
567 
568 static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
569 {
570 	u32 *iopgd = iopgd_offset(obj, da);
571 	u32 *iopte = iopte_alloc(obj, iopgd, da);
572 	int i;
573 
574 	if ((da | pa) & ~IOLARGE_MASK) {
575 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
576 			__func__, da, pa, IOLARGE_SIZE);
577 		return -EINVAL;
578 	}
579 
580 	if (IS_ERR(iopte))
581 		return PTR_ERR(iopte);
582 
583 	for (i = 0; i < 16; i++)
584 		*(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
585 	flush_iopte_range(iopte, iopte + 15);
586 	return 0;
587 }
588 
589 static int
590 iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
591 {
592 	int (*fn)(struct omap_iommu *, u32, u32, u32);
593 	u32 prot;
594 	int err;
595 
596 	if (!obj || !e)
597 		return -EINVAL;
598 
599 	switch (e->pgsz) {
600 	case MMU_CAM_PGSZ_16M:
601 		fn = iopgd_alloc_super;
602 		break;
603 	case MMU_CAM_PGSZ_1M:
604 		fn = iopgd_alloc_section;
605 		break;
606 	case MMU_CAM_PGSZ_64K:
607 		fn = iopte_alloc_large;
608 		break;
609 	case MMU_CAM_PGSZ_4K:
610 		fn = iopte_alloc_page;
611 		break;
612 	default:
613 		fn = NULL;
614 		BUG();
615 		break;
616 	}
617 
618 	prot = get_iopte_attr(e);
619 
620 	spin_lock(&obj->page_table_lock);
621 	err = fn(obj, e->da, e->pa, prot);
622 	spin_unlock(&obj->page_table_lock);
623 
624 	return err;
625 }
626 
627 /**
628  * omap_iopgtable_store_entry - Make an iommu pte entry
629  * @obj:	target iommu
630  * @e:		an iommu tlb entry info
631  **/
632 static int
633 omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
634 {
635 	int err;
636 
637 	flush_iotlb_page(obj, e->da);
638 	err = iopgtable_store_entry_core(obj, e);
639 	if (!err)
640 		prefetch_iotlb_entry(obj, e);
641 	return err;
642 }
643 
644 /**
645  * iopgtable_lookup_entry - Lookup an iommu pte entry
646  * @obj:	target iommu
647  * @da:		iommu device virtual address
648  * @ppgd:	iommu pgd entry pointer to be returned
649  * @ppte:	iommu pte entry pointer to be returned
650  **/
651 static void
652 iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
653 {
654 	u32 *iopgd, *iopte = NULL;
655 
656 	iopgd = iopgd_offset(obj, da);
657 	if (!*iopgd)
658 		goto out;
659 
660 	if (iopgd_is_table(*iopgd))
661 		iopte = iopte_offset(iopgd, da);
662 out:
663 	*ppgd = iopgd;
664 	*ppte = iopte;
665 }
666 
667 static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
668 {
669 	size_t bytes;
670 	u32 *iopgd = iopgd_offset(obj, da);
671 	int nent = 1;
672 
673 	if (!*iopgd)
674 		return 0;
675 
676 	if (iopgd_is_table(*iopgd)) {
677 		int i;
678 		u32 *iopte = iopte_offset(iopgd, da);
679 
680 		bytes = IOPTE_SIZE;
681 		if (*iopte & IOPTE_LARGE) {
682 			nent *= 16;
683 			/* rewind to the 1st entry */
684 			iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
685 		}
686 		bytes *= nent;
687 		memset(iopte, 0, nent * sizeof(*iopte));
688 		flush_iopte_range(iopte, iopte + (nent - 1) * sizeof(*iopte));
689 
690 		/*
691 		 * do table walk to check if this table is necessary or not
692 		 */
693 		iopte = iopte_offset(iopgd, 0);
694 		for (i = 0; i < PTRS_PER_IOPTE; i++)
695 			if (iopte[i])
696 				goto out;
697 
698 		iopte_free(iopte);
699 		nent = 1; /* for the next L1 entry */
700 	} else {
701 		bytes = IOPGD_SIZE;
702 		if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
703 			nent *= 16;
704 			/* rewind to the 1st entry */
705 			iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
706 		}
707 		bytes *= nent;
708 	}
709 	memset(iopgd, 0, nent * sizeof(*iopgd));
710 	flush_iopgd_range(iopgd, iopgd + (nent - 1) * sizeof(*iopgd));
711 out:
712 	return bytes;
713 }
714 
715 /**
716  * iopgtable_clear_entry - Remove an iommu pte entry
717  * @obj:	target iommu
718  * @da:		iommu device virtual address
719  **/
720 static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
721 {
722 	size_t bytes;
723 
724 	spin_lock(&obj->page_table_lock);
725 
726 	bytes = iopgtable_clear_entry_core(obj, da);
727 	flush_iotlb_page(obj, da);
728 
729 	spin_unlock(&obj->page_table_lock);
730 
731 	return bytes;
732 }
733 
734 static void iopgtable_clear_entry_all(struct omap_iommu *obj)
735 {
736 	int i;
737 
738 	spin_lock(&obj->page_table_lock);
739 
740 	for (i = 0; i < PTRS_PER_IOPGD; i++) {
741 		u32 da;
742 		u32 *iopgd;
743 
744 		da = i << IOPGD_SHIFT;
745 		iopgd = iopgd_offset(obj, da);
746 
747 		if (!*iopgd)
748 			continue;
749 
750 		if (iopgd_is_table(*iopgd))
751 			iopte_free(iopte_offset(iopgd, 0));
752 
753 		*iopgd = 0;
754 		flush_iopgd_range(iopgd, iopgd);
755 	}
756 
757 	flush_iotlb_all(obj);
758 
759 	spin_unlock(&obj->page_table_lock);
760 }
761 
762 /*
763  *	Device IOMMU generic operations
764  */
765 static irqreturn_t iommu_fault_handler(int irq, void *data)
766 {
767 	u32 da, errs;
768 	u32 *iopgd, *iopte;
769 	struct omap_iommu *obj = data;
770 	struct iommu_domain *domain = obj->domain;
771 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
772 
773 	if (!omap_domain->iommu_dev)
774 		return IRQ_NONE;
775 
776 	errs = iommu_report_fault(obj, &da);
777 	if (errs == 0)
778 		return IRQ_HANDLED;
779 
780 	/* Fault callback or TLB/PTE Dynamic loading */
781 	if (!report_iommu_fault(domain, obj->dev, da, 0))
782 		return IRQ_HANDLED;
783 
784 	iommu_disable(obj);
785 
786 	iopgd = iopgd_offset(obj, da);
787 
788 	if (!iopgd_is_table(*iopgd)) {
789 		dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
790 			obj->name, errs, da, iopgd, *iopgd);
791 		return IRQ_NONE;
792 	}
793 
794 	iopte = iopte_offset(iopgd, da);
795 
796 	dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
797 		obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
798 
799 	return IRQ_NONE;
800 }
801 
802 static int device_match_by_alias(struct device *dev, void *data)
803 {
804 	struct omap_iommu *obj = to_iommu(dev);
805 	const char *name = data;
806 
807 	pr_debug("%s: %s %s\n", __func__, obj->name, name);
808 
809 	return strcmp(obj->name, name) == 0;
810 }
811 
812 /**
813  * omap_iommu_attach() - attach iommu device to an iommu domain
814  * @name:	name of target omap iommu device
815  * @iopgd:	page table
816  **/
817 static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
818 {
819 	int err;
820 	struct device *dev;
821 	struct omap_iommu *obj;
822 
823 	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
824 				 device_match_by_alias);
825 	if (!dev)
826 		return ERR_PTR(-ENODEV);
827 
828 	obj = to_iommu(dev);
829 
830 	spin_lock(&obj->iommu_lock);
831 
832 	obj->iopgd = iopgd;
833 	err = iommu_enable(obj);
834 	if (err)
835 		goto err_enable;
836 	flush_iotlb_all(obj);
837 
838 	spin_unlock(&obj->iommu_lock);
839 
840 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
841 	return obj;
842 
843 err_enable:
844 	spin_unlock(&obj->iommu_lock);
845 	return ERR_PTR(err);
846 }
847 
848 /**
849  * omap_iommu_detach - release iommu device
850  * @obj:	target iommu
851  **/
852 static void omap_iommu_detach(struct omap_iommu *obj)
853 {
854 	if (!obj || IS_ERR(obj))
855 		return;
856 
857 	spin_lock(&obj->iommu_lock);
858 
859 	iommu_disable(obj);
860 	obj->iopgd = NULL;
861 
862 	spin_unlock(&obj->iommu_lock);
863 
864 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
865 }
866 
867 /*
868  *	OMAP Device MMU(IOMMU) detection
869  */
870 static int omap_iommu_probe(struct platform_device *pdev)
871 {
872 	int err = -ENODEV;
873 	int irq;
874 	struct omap_iommu *obj;
875 	struct resource *res;
876 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
877 	struct device_node *of = pdev->dev.of_node;
878 
879 	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
880 	if (!obj)
881 		return -ENOMEM;
882 
883 	if (of) {
884 		obj->name = dev_name(&pdev->dev);
885 		obj->nr_tlb_entries = 32;
886 		err = of_property_read_u32(of, "ti,#tlb-entries",
887 					   &obj->nr_tlb_entries);
888 		if (err && err != -EINVAL)
889 			return err;
890 		if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
891 			return -EINVAL;
892 		if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
893 			obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
894 	} else {
895 		obj->nr_tlb_entries = pdata->nr_tlb_entries;
896 		obj->name = pdata->name;
897 	}
898 
899 	obj->dev = &pdev->dev;
900 	obj->ctx = (void *)obj + sizeof(*obj);
901 
902 	spin_lock_init(&obj->iommu_lock);
903 	spin_lock_init(&obj->page_table_lock);
904 
905 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
906 	obj->regbase = devm_ioremap_resource(obj->dev, res);
907 	if (IS_ERR(obj->regbase))
908 		return PTR_ERR(obj->regbase);
909 
910 	irq = platform_get_irq(pdev, 0);
911 	if (irq < 0)
912 		return -ENODEV;
913 
914 	err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
915 			       dev_name(obj->dev), obj);
916 	if (err < 0)
917 		return err;
918 	platform_set_drvdata(pdev, obj);
919 
920 	pm_runtime_irq_safe(obj->dev);
921 	pm_runtime_enable(obj->dev);
922 
923 	omap_iommu_debugfs_add(obj);
924 
925 	dev_info(&pdev->dev, "%s registered\n", obj->name);
926 	return 0;
927 }
928 
929 static int omap_iommu_remove(struct platform_device *pdev)
930 {
931 	struct omap_iommu *obj = platform_get_drvdata(pdev);
932 
933 	iopgtable_clear_entry_all(obj);
934 	omap_iommu_debugfs_remove(obj);
935 
936 	pm_runtime_disable(obj->dev);
937 
938 	dev_info(&pdev->dev, "%s removed\n", obj->name);
939 	return 0;
940 }
941 
942 static const struct of_device_id omap_iommu_of_match[] = {
943 	{ .compatible = "ti,omap2-iommu" },
944 	{ .compatible = "ti,omap4-iommu" },
945 	{ .compatible = "ti,dra7-iommu"	},
946 	{},
947 };
948 
949 static struct platform_driver omap_iommu_driver = {
950 	.probe	= omap_iommu_probe,
951 	.remove	= omap_iommu_remove,
952 	.driver	= {
953 		.name	= "omap-iommu",
954 		.of_match_table = of_match_ptr(omap_iommu_of_match),
955 	},
956 };
957 
958 static void iopte_cachep_ctor(void *iopte)
959 {
960 	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);
961 }
962 
963 static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
964 {
965 	memset(e, 0, sizeof(*e));
966 
967 	e->da		= da;
968 	e->pa		= pa;
969 	e->valid	= MMU_CAM_V;
970 	e->pgsz		= pgsz;
971 	e->endian	= MMU_RAM_ENDIAN_LITTLE;
972 	e->elsz		= MMU_RAM_ELSZ_8;
973 	e->mixed	= 0;
974 
975 	return iopgsz_to_bytes(e->pgsz);
976 }
977 
978 static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
979 			  phys_addr_t pa, size_t bytes, int prot)
980 {
981 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
982 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
983 	struct device *dev = oiommu->dev;
984 	struct iotlb_entry e;
985 	int omap_pgsz;
986 	u32 ret;
987 
988 	omap_pgsz = bytes_to_iopgsz(bytes);
989 	if (omap_pgsz < 0) {
990 		dev_err(dev, "invalid size to map: %d\n", bytes);
991 		return -EINVAL;
992 	}
993 
994 	dev_dbg(dev, "mapping da 0x%lx to pa %pa size 0x%x\n", da, &pa, bytes);
995 
996 	iotlb_init_entry(&e, da, pa, omap_pgsz);
997 
998 	ret = omap_iopgtable_store_entry(oiommu, &e);
999 	if (ret)
1000 		dev_err(dev, "omap_iopgtable_store_entry failed: %d\n", ret);
1001 
1002 	return ret;
1003 }
1004 
1005 static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
1006 			       size_t size)
1007 {
1008 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1009 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1010 	struct device *dev = oiommu->dev;
1011 
1012 	dev_dbg(dev, "unmapping da 0x%lx size %u\n", da, size);
1013 
1014 	return iopgtable_clear_entry(oiommu, da);
1015 }
1016 
1017 static int
1018 omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
1019 {
1020 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1021 	struct omap_iommu *oiommu;
1022 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1023 	int ret = 0;
1024 
1025 	if (!arch_data || !arch_data->name) {
1026 		dev_err(dev, "device doesn't have an associated iommu\n");
1027 		return -EINVAL;
1028 	}
1029 
1030 	spin_lock(&omap_domain->lock);
1031 
1032 	/* only a single device is supported per domain for now */
1033 	if (omap_domain->iommu_dev) {
1034 		dev_err(dev, "iommu domain is already attached\n");
1035 		ret = -EBUSY;
1036 		goto out;
1037 	}
1038 
1039 	/* get a handle to and enable the omap iommu */
1040 	oiommu = omap_iommu_attach(arch_data->name, omap_domain->pgtable);
1041 	if (IS_ERR(oiommu)) {
1042 		ret = PTR_ERR(oiommu);
1043 		dev_err(dev, "can't get omap iommu: %d\n", ret);
1044 		goto out;
1045 	}
1046 
1047 	omap_domain->iommu_dev = arch_data->iommu_dev = oiommu;
1048 	omap_domain->dev = dev;
1049 	oiommu->domain = domain;
1050 
1051 out:
1052 	spin_unlock(&omap_domain->lock);
1053 	return ret;
1054 }
1055 
1056 static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
1057 				   struct device *dev)
1058 {
1059 	struct omap_iommu *oiommu = dev_to_omap_iommu(dev);
1060 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1061 
1062 	/* only a single device is supported per domain for now */
1063 	if (omap_domain->iommu_dev != oiommu) {
1064 		dev_err(dev, "invalid iommu device\n");
1065 		return;
1066 	}
1067 
1068 	iopgtable_clear_entry_all(oiommu);
1069 
1070 	omap_iommu_detach(oiommu);
1071 
1072 	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;
1073 	omap_domain->dev = NULL;
1074 	oiommu->domain = NULL;
1075 }
1076 
1077 static void omap_iommu_detach_dev(struct iommu_domain *domain,
1078 				  struct device *dev)
1079 {
1080 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1081 
1082 	spin_lock(&omap_domain->lock);
1083 	_omap_iommu_detach_dev(omap_domain, dev);
1084 	spin_unlock(&omap_domain->lock);
1085 }
1086 
1087 static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
1088 {
1089 	struct omap_iommu_domain *omap_domain;
1090 
1091 	if (type != IOMMU_DOMAIN_UNMANAGED)
1092 		return NULL;
1093 
1094 	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
1095 	if (!omap_domain)
1096 		goto out;
1097 
1098 	omap_domain->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_KERNEL);
1099 	if (!omap_domain->pgtable)
1100 		goto fail_nomem;
1101 
1102 	/*
1103 	 * should never fail, but please keep this around to ensure
1104 	 * we keep the hardware happy
1105 	 */
1106 	BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));
1107 
1108 	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);
1109 	spin_lock_init(&omap_domain->lock);
1110 
1111 	omap_domain->domain.geometry.aperture_start = 0;
1112 	omap_domain->domain.geometry.aperture_end   = (1ULL << 32) - 1;
1113 	omap_domain->domain.geometry.force_aperture = true;
1114 
1115 	return &omap_domain->domain;
1116 
1117 fail_nomem:
1118 	kfree(omap_domain);
1119 out:
1120 	return NULL;
1121 }
1122 
1123 static void omap_iommu_domain_free(struct iommu_domain *domain)
1124 {
1125 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1126 
1127 	/*
1128 	 * An iommu device is still attached
1129 	 * (currently, only one device can be attached) ?
1130 	 */
1131 	if (omap_domain->iommu_dev)
1132 		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
1133 
1134 	kfree(omap_domain->pgtable);
1135 	kfree(omap_domain);
1136 }
1137 
1138 static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
1139 					   dma_addr_t da)
1140 {
1141 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1142 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1143 	struct device *dev = oiommu->dev;
1144 	u32 *pgd, *pte;
1145 	phys_addr_t ret = 0;
1146 
1147 	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
1148 
1149 	if (pte) {
1150 		if (iopte_is_small(*pte))
1151 			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
1152 		else if (iopte_is_large(*pte))
1153 			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
1154 		else
1155 			dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
1156 				(unsigned long long)da);
1157 	} else {
1158 		if (iopgd_is_section(*pgd))
1159 			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
1160 		else if (iopgd_is_super(*pgd))
1161 			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
1162 		else
1163 			dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
1164 				(unsigned long long)da);
1165 	}
1166 
1167 	return ret;
1168 }
1169 
1170 static int omap_iommu_add_device(struct device *dev)
1171 {
1172 	struct omap_iommu_arch_data *arch_data;
1173 	struct device_node *np;
1174 	struct platform_device *pdev;
1175 
1176 	/*
1177 	 * Allocate the archdata iommu structure for DT-based devices.
1178 	 *
1179 	 * TODO: Simplify this when removing non-DT support completely from the
1180 	 * IOMMU users.
1181 	 */
1182 	if (!dev->of_node)
1183 		return 0;
1184 
1185 	np = of_parse_phandle(dev->of_node, "iommus", 0);
1186 	if (!np)
1187 		return 0;
1188 
1189 	pdev = of_find_device_by_node(np);
1190 	if (WARN_ON(!pdev)) {
1191 		of_node_put(np);
1192 		return -EINVAL;
1193 	}
1194 
1195 	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
1196 	if (!arch_data) {
1197 		of_node_put(np);
1198 		return -ENOMEM;
1199 	}
1200 
1201 	arch_data->name = kstrdup(dev_name(&pdev->dev), GFP_KERNEL);
1202 	dev->archdata.iommu = arch_data;
1203 
1204 	of_node_put(np);
1205 
1206 	return 0;
1207 }
1208 
1209 static void omap_iommu_remove_device(struct device *dev)
1210 {
1211 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1212 
1213 	if (!dev->of_node || !arch_data)
1214 		return;
1215 
1216 	kfree(arch_data->name);
1217 	kfree(arch_data);
1218 }
1219 
1220 static const struct iommu_ops omap_iommu_ops = {
1221 	.domain_alloc	= omap_iommu_domain_alloc,
1222 	.domain_free	= omap_iommu_domain_free,
1223 	.attach_dev	= omap_iommu_attach_dev,
1224 	.detach_dev	= omap_iommu_detach_dev,
1225 	.map		= omap_iommu_map,
1226 	.unmap		= omap_iommu_unmap,
1227 	.map_sg		= default_iommu_map_sg,
1228 	.iova_to_phys	= omap_iommu_iova_to_phys,
1229 	.add_device	= omap_iommu_add_device,
1230 	.remove_device	= omap_iommu_remove_device,
1231 	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
1232 };
1233 
1234 static int __init omap_iommu_init(void)
1235 {
1236 	struct kmem_cache *p;
1237 	const unsigned long flags = SLAB_HWCACHE_ALIGN;
1238 	size_t align = 1 << 10; /* L2 pagetable alignement */
1239 	struct device_node *np;
1240 
1241 	np = of_find_matching_node(NULL, omap_iommu_of_match);
1242 	if (!np)
1243 		return 0;
1244 
1245 	of_node_put(np);
1246 
1247 	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
1248 			      iopte_cachep_ctor);
1249 	if (!p)
1250 		return -ENOMEM;
1251 	iopte_cachep = p;
1252 
1253 	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
1254 
1255 	omap_iommu_debugfs_init();
1256 
1257 	return platform_driver_register(&omap_iommu_driver);
1258 }
1259 subsys_initcall(omap_iommu_init);
1260 /* must be ready before omap3isp is probed */
1261