xref: /openbmc/linux/drivers/iommu/omap-iommu.c (revision 7587eb18)
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 #include <linux/regmap.h>
30 #include <linux/mfd/syscon.h>
31 
32 #include <asm/cacheflush.h>
33 
34 #include <linux/platform_data/iommu-omap.h>
35 
36 #include "omap-iopgtable.h"
37 #include "omap-iommu.h"
38 
39 #define to_iommu(dev)							\
40 	((struct omap_iommu *)platform_get_drvdata(to_platform_device(dev)))
41 
42 /* bitmap of the page sizes currently supported */
43 #define OMAP_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
44 
45 /**
46  * struct omap_iommu_domain - omap iommu domain
47  * @pgtable:	the page table
48  * @iommu_dev:	an omap iommu device attached to this domain. only a single
49  *		iommu device can be attached for now.
50  * @dev:	Device using this domain.
51  * @lock:	domain lock, should be taken when attaching/detaching
52  */
53 struct omap_iommu_domain {
54 	u32 *pgtable;
55 	struct omap_iommu *iommu_dev;
56 	struct device *dev;
57 	spinlock_t lock;
58 	struct iommu_domain domain;
59 };
60 
61 #define MMU_LOCK_BASE_SHIFT	10
62 #define MMU_LOCK_BASE_MASK	(0x1f << MMU_LOCK_BASE_SHIFT)
63 #define MMU_LOCK_BASE(x)	\
64 	((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
65 
66 #define MMU_LOCK_VICT_SHIFT	4
67 #define MMU_LOCK_VICT_MASK	(0x1f << MMU_LOCK_VICT_SHIFT)
68 #define MMU_LOCK_VICT(x)	\
69 	((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
70 
71 static struct platform_driver omap_iommu_driver;
72 static struct kmem_cache *iopte_cachep;
73 
74 /**
75  * to_omap_domain - Get struct omap_iommu_domain from generic iommu_domain
76  * @dom:	generic iommu domain handle
77  **/
78 static struct omap_iommu_domain *to_omap_domain(struct iommu_domain *dom)
79 {
80 	return container_of(dom, struct omap_iommu_domain, domain);
81 }
82 
83 /**
84  * omap_iommu_save_ctx - Save registers for pm off-mode support
85  * @dev:	client device
86  **/
87 void omap_iommu_save_ctx(struct device *dev)
88 {
89 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
90 	u32 *p = obj->ctx;
91 	int i;
92 
93 	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
94 		p[i] = iommu_read_reg(obj, i * sizeof(u32));
95 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
96 	}
97 }
98 EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
99 
100 /**
101  * omap_iommu_restore_ctx - Restore registers for pm off-mode support
102  * @dev:	client device
103  **/
104 void omap_iommu_restore_ctx(struct device *dev)
105 {
106 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
107 	u32 *p = obj->ctx;
108 	int i;
109 
110 	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
111 		iommu_write_reg(obj, p[i], i * sizeof(u32));
112 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
113 	}
114 }
115 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
116 
117 static void dra7_cfg_dspsys_mmu(struct omap_iommu *obj, bool enable)
118 {
119 	u32 val, mask;
120 
121 	if (!obj->syscfg)
122 		return;
123 
124 	mask = (1 << (obj->id * DSP_SYS_MMU_CONFIG_EN_SHIFT));
125 	val = enable ? mask : 0;
126 	regmap_update_bits(obj->syscfg, DSP_SYS_MMU_CONFIG, mask, val);
127 }
128 
129 static void __iommu_set_twl(struct omap_iommu *obj, bool on)
130 {
131 	u32 l = iommu_read_reg(obj, MMU_CNTL);
132 
133 	if (on)
134 		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
135 	else
136 		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
137 
138 	l &= ~MMU_CNTL_MASK;
139 	if (on)
140 		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
141 	else
142 		l |= (MMU_CNTL_MMU_EN);
143 
144 	iommu_write_reg(obj, l, MMU_CNTL);
145 }
146 
147 static int omap2_iommu_enable(struct omap_iommu *obj)
148 {
149 	u32 l, pa;
150 
151 	if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
152 		return -EINVAL;
153 
154 	pa = virt_to_phys(obj->iopgd);
155 	if (!IS_ALIGNED(pa, SZ_16K))
156 		return -EINVAL;
157 
158 	l = iommu_read_reg(obj, MMU_REVISION);
159 	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
160 		 (l >> 4) & 0xf, l & 0xf);
161 
162 	iommu_write_reg(obj, pa, MMU_TTB);
163 
164 	dra7_cfg_dspsys_mmu(obj, true);
165 
166 	if (obj->has_bus_err_back)
167 		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
168 
169 	__iommu_set_twl(obj, true);
170 
171 	return 0;
172 }
173 
174 static void omap2_iommu_disable(struct omap_iommu *obj)
175 {
176 	u32 l = iommu_read_reg(obj, MMU_CNTL);
177 
178 	l &= ~MMU_CNTL_MASK;
179 	iommu_write_reg(obj, l, MMU_CNTL);
180 	dra7_cfg_dspsys_mmu(obj, false);
181 
182 	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
183 }
184 
185 static int iommu_enable(struct omap_iommu *obj)
186 {
187 	int err;
188 	struct platform_device *pdev = to_platform_device(obj->dev);
189 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
190 
191 	if (pdata && pdata->deassert_reset) {
192 		err = pdata->deassert_reset(pdev, pdata->reset_name);
193 		if (err) {
194 			dev_err(obj->dev, "deassert_reset failed: %d\n", err);
195 			return err;
196 		}
197 	}
198 
199 	pm_runtime_get_sync(obj->dev);
200 
201 	err = omap2_iommu_enable(obj);
202 
203 	return err;
204 }
205 
206 static void iommu_disable(struct omap_iommu *obj)
207 {
208 	struct platform_device *pdev = to_platform_device(obj->dev);
209 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
210 
211 	omap2_iommu_disable(obj);
212 
213 	pm_runtime_put_sync(obj->dev);
214 
215 	if (pdata && pdata->assert_reset)
216 		pdata->assert_reset(pdev, pdata->reset_name);
217 }
218 
219 /*
220  *	TLB operations
221  */
222 static u32 iotlb_cr_to_virt(struct cr_regs *cr)
223 {
224 	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
225 	u32 mask = get_cam_va_mask(cr->cam & page_size);
226 
227 	return cr->cam & mask;
228 }
229 
230 static u32 get_iopte_attr(struct iotlb_entry *e)
231 {
232 	u32 attr;
233 
234 	attr = e->mixed << 5;
235 	attr |= e->endian;
236 	attr |= e->elsz >> 3;
237 	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
238 			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
239 	return attr;
240 }
241 
242 static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
243 {
244 	u32 status, fault_addr;
245 
246 	status = iommu_read_reg(obj, MMU_IRQSTATUS);
247 	status &= MMU_IRQ_MASK;
248 	if (!status) {
249 		*da = 0;
250 		return 0;
251 	}
252 
253 	fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
254 	*da = fault_addr;
255 
256 	iommu_write_reg(obj, status, MMU_IRQSTATUS);
257 
258 	return status;
259 }
260 
261 void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
262 {
263 	u32 val;
264 
265 	val = iommu_read_reg(obj, MMU_LOCK);
266 
267 	l->base = MMU_LOCK_BASE(val);
268 	l->vict = MMU_LOCK_VICT(val);
269 }
270 
271 void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
272 {
273 	u32 val;
274 
275 	val = (l->base << MMU_LOCK_BASE_SHIFT);
276 	val |= (l->vict << MMU_LOCK_VICT_SHIFT);
277 
278 	iommu_write_reg(obj, val, MMU_LOCK);
279 }
280 
281 static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
282 {
283 	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
284 	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
285 }
286 
287 static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
288 {
289 	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
290 	iommu_write_reg(obj, cr->ram, MMU_RAM);
291 
292 	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
293 	iommu_write_reg(obj, 1, MMU_LD_TLB);
294 }
295 
296 /* only used in iotlb iteration for-loop */
297 struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
298 {
299 	struct cr_regs cr;
300 	struct iotlb_lock l;
301 
302 	iotlb_lock_get(obj, &l);
303 	l.vict = n;
304 	iotlb_lock_set(obj, &l);
305 	iotlb_read_cr(obj, &cr);
306 
307 	return cr;
308 }
309 
310 #ifdef PREFETCH_IOTLB
311 static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
312 				      struct iotlb_entry *e)
313 {
314 	struct cr_regs *cr;
315 
316 	if (!e)
317 		return NULL;
318 
319 	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
320 		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
321 			e->da);
322 		return ERR_PTR(-EINVAL);
323 	}
324 
325 	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
326 	if (!cr)
327 		return ERR_PTR(-ENOMEM);
328 
329 	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
330 	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
331 
332 	return cr;
333 }
334 
335 /**
336  * load_iotlb_entry - Set an iommu tlb entry
337  * @obj:	target iommu
338  * @e:		an iommu tlb entry info
339  **/
340 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
341 {
342 	int err = 0;
343 	struct iotlb_lock l;
344 	struct cr_regs *cr;
345 
346 	if (!obj || !obj->nr_tlb_entries || !e)
347 		return -EINVAL;
348 
349 	pm_runtime_get_sync(obj->dev);
350 
351 	iotlb_lock_get(obj, &l);
352 	if (l.base == obj->nr_tlb_entries) {
353 		dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
354 		err = -EBUSY;
355 		goto out;
356 	}
357 	if (!e->prsvd) {
358 		int i;
359 		struct cr_regs tmp;
360 
361 		for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
362 			if (!iotlb_cr_valid(&tmp))
363 				break;
364 
365 		if (i == obj->nr_tlb_entries) {
366 			dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
367 			err = -EBUSY;
368 			goto out;
369 		}
370 
371 		iotlb_lock_get(obj, &l);
372 	} else {
373 		l.vict = l.base;
374 		iotlb_lock_set(obj, &l);
375 	}
376 
377 	cr = iotlb_alloc_cr(obj, e);
378 	if (IS_ERR(cr)) {
379 		pm_runtime_put_sync(obj->dev);
380 		return PTR_ERR(cr);
381 	}
382 
383 	iotlb_load_cr(obj, cr);
384 	kfree(cr);
385 
386 	if (e->prsvd)
387 		l.base++;
388 	/* increment victim for next tlb load */
389 	if (++l.vict == obj->nr_tlb_entries)
390 		l.vict = l.base;
391 	iotlb_lock_set(obj, &l);
392 out:
393 	pm_runtime_put_sync(obj->dev);
394 	return err;
395 }
396 
397 #else /* !PREFETCH_IOTLB */
398 
399 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
400 {
401 	return 0;
402 }
403 
404 #endif /* !PREFETCH_IOTLB */
405 
406 static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
407 {
408 	return load_iotlb_entry(obj, e);
409 }
410 
411 /**
412  * flush_iotlb_page - Clear an iommu tlb entry
413  * @obj:	target iommu
414  * @da:		iommu device virtual address
415  *
416  * Clear an iommu tlb entry which includes 'da' address.
417  **/
418 static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
419 {
420 	int i;
421 	struct cr_regs cr;
422 
423 	pm_runtime_get_sync(obj->dev);
424 
425 	for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
426 		u32 start;
427 		size_t bytes;
428 
429 		if (!iotlb_cr_valid(&cr))
430 			continue;
431 
432 		start = iotlb_cr_to_virt(&cr);
433 		bytes = iopgsz_to_bytes(cr.cam & 3);
434 
435 		if ((start <= da) && (da < start + bytes)) {
436 			dev_dbg(obj->dev, "%s: %08x<=%08x(%x)\n",
437 				__func__, start, da, bytes);
438 			iotlb_load_cr(obj, &cr);
439 			iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
440 			break;
441 		}
442 	}
443 	pm_runtime_put_sync(obj->dev);
444 
445 	if (i == obj->nr_tlb_entries)
446 		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
447 }
448 
449 /**
450  * flush_iotlb_all - Clear all iommu tlb entries
451  * @obj:	target iommu
452  **/
453 static void flush_iotlb_all(struct omap_iommu *obj)
454 {
455 	struct iotlb_lock l;
456 
457 	pm_runtime_get_sync(obj->dev);
458 
459 	l.base = 0;
460 	l.vict = 0;
461 	iotlb_lock_set(obj, &l);
462 
463 	iommu_write_reg(obj, 1, MMU_GFLUSH);
464 
465 	pm_runtime_put_sync(obj->dev);
466 }
467 
468 /*
469  *	H/W pagetable operations
470  */
471 static void flush_iopgd_range(u32 *first, u32 *last)
472 {
473 	/* FIXME: L2 cache should be taken care of if it exists */
474 	do {
475 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pgd"
476 		    : : "r" (first));
477 		first += L1_CACHE_BYTES / sizeof(*first);
478 	} while (first <= last);
479 }
480 
481 static void flush_iopte_range(u32 *first, u32 *last)
482 {
483 	/* FIXME: L2 cache should be taken care of if it exists */
484 	do {
485 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pte"
486 		    : : "r" (first));
487 		first += L1_CACHE_BYTES / sizeof(*first);
488 	} while (first <= last);
489 }
490 
491 static void iopte_free(u32 *iopte)
492 {
493 	/* Note: freed iopte's must be clean ready for re-use */
494 	if (iopte)
495 		kmem_cache_free(iopte_cachep, iopte);
496 }
497 
498 static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd, u32 da)
499 {
500 	u32 *iopte;
501 
502 	/* a table has already existed */
503 	if (*iopgd)
504 		goto pte_ready;
505 
506 	/*
507 	 * do the allocation outside the page table lock
508 	 */
509 	spin_unlock(&obj->page_table_lock);
510 	iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
511 	spin_lock(&obj->page_table_lock);
512 
513 	if (!*iopgd) {
514 		if (!iopte)
515 			return ERR_PTR(-ENOMEM);
516 
517 		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
518 		flush_iopgd_range(iopgd, iopgd);
519 
520 		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
521 	} else {
522 		/* We raced, free the reduniovant table */
523 		iopte_free(iopte);
524 	}
525 
526 pte_ready:
527 	iopte = iopte_offset(iopgd, da);
528 
529 	dev_vdbg(obj->dev,
530 		 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
531 		 __func__, da, iopgd, *iopgd, iopte, *iopte);
532 
533 	return iopte;
534 }
535 
536 static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
537 {
538 	u32 *iopgd = iopgd_offset(obj, da);
539 
540 	if ((da | pa) & ~IOSECTION_MASK) {
541 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
542 			__func__, da, pa, IOSECTION_SIZE);
543 		return -EINVAL;
544 	}
545 
546 	*iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
547 	flush_iopgd_range(iopgd, iopgd);
548 	return 0;
549 }
550 
551 static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
552 {
553 	u32 *iopgd = iopgd_offset(obj, da);
554 	int i;
555 
556 	if ((da | pa) & ~IOSUPER_MASK) {
557 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
558 			__func__, da, pa, IOSUPER_SIZE);
559 		return -EINVAL;
560 	}
561 
562 	for (i = 0; i < 16; i++)
563 		*(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
564 	flush_iopgd_range(iopgd, iopgd + 15);
565 	return 0;
566 }
567 
568 static int iopte_alloc_page(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 
573 	if (IS_ERR(iopte))
574 		return PTR_ERR(iopte);
575 
576 	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
577 	flush_iopte_range(iopte, iopte);
578 
579 	dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
580 		 __func__, da, pa, iopte, *iopte);
581 
582 	return 0;
583 }
584 
585 static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
586 {
587 	u32 *iopgd = iopgd_offset(obj, da);
588 	u32 *iopte = iopte_alloc(obj, iopgd, da);
589 	int i;
590 
591 	if ((da | pa) & ~IOLARGE_MASK) {
592 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
593 			__func__, da, pa, IOLARGE_SIZE);
594 		return -EINVAL;
595 	}
596 
597 	if (IS_ERR(iopte))
598 		return PTR_ERR(iopte);
599 
600 	for (i = 0; i < 16; i++)
601 		*(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
602 	flush_iopte_range(iopte, iopte + 15);
603 	return 0;
604 }
605 
606 static int
607 iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
608 {
609 	int (*fn)(struct omap_iommu *, u32, u32, u32);
610 	u32 prot;
611 	int err;
612 
613 	if (!obj || !e)
614 		return -EINVAL;
615 
616 	switch (e->pgsz) {
617 	case MMU_CAM_PGSZ_16M:
618 		fn = iopgd_alloc_super;
619 		break;
620 	case MMU_CAM_PGSZ_1M:
621 		fn = iopgd_alloc_section;
622 		break;
623 	case MMU_CAM_PGSZ_64K:
624 		fn = iopte_alloc_large;
625 		break;
626 	case MMU_CAM_PGSZ_4K:
627 		fn = iopte_alloc_page;
628 		break;
629 	default:
630 		fn = NULL;
631 		break;
632 	}
633 
634 	if (WARN_ON(!fn))
635 		return -EINVAL;
636 
637 	prot = get_iopte_attr(e);
638 
639 	spin_lock(&obj->page_table_lock);
640 	err = fn(obj, e->da, e->pa, prot);
641 	spin_unlock(&obj->page_table_lock);
642 
643 	return err;
644 }
645 
646 /**
647  * omap_iopgtable_store_entry - Make an iommu pte entry
648  * @obj:	target iommu
649  * @e:		an iommu tlb entry info
650  **/
651 static int
652 omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
653 {
654 	int err;
655 
656 	flush_iotlb_page(obj, e->da);
657 	err = iopgtable_store_entry_core(obj, e);
658 	if (!err)
659 		prefetch_iotlb_entry(obj, e);
660 	return err;
661 }
662 
663 /**
664  * iopgtable_lookup_entry - Lookup an iommu pte entry
665  * @obj:	target iommu
666  * @da:		iommu device virtual address
667  * @ppgd:	iommu pgd entry pointer to be returned
668  * @ppte:	iommu pte entry pointer to be returned
669  **/
670 static void
671 iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
672 {
673 	u32 *iopgd, *iopte = NULL;
674 
675 	iopgd = iopgd_offset(obj, da);
676 	if (!*iopgd)
677 		goto out;
678 
679 	if (iopgd_is_table(*iopgd))
680 		iopte = iopte_offset(iopgd, da);
681 out:
682 	*ppgd = iopgd;
683 	*ppte = iopte;
684 }
685 
686 static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
687 {
688 	size_t bytes;
689 	u32 *iopgd = iopgd_offset(obj, da);
690 	int nent = 1;
691 
692 	if (!*iopgd)
693 		return 0;
694 
695 	if (iopgd_is_table(*iopgd)) {
696 		int i;
697 		u32 *iopte = iopte_offset(iopgd, da);
698 
699 		bytes = IOPTE_SIZE;
700 		if (*iopte & IOPTE_LARGE) {
701 			nent *= 16;
702 			/* rewind to the 1st entry */
703 			iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
704 		}
705 		bytes *= nent;
706 		memset(iopte, 0, nent * sizeof(*iopte));
707 		flush_iopte_range(iopte, iopte + (nent - 1) * sizeof(*iopte));
708 
709 		/*
710 		 * do table walk to check if this table is necessary or not
711 		 */
712 		iopte = iopte_offset(iopgd, 0);
713 		for (i = 0; i < PTRS_PER_IOPTE; i++)
714 			if (iopte[i])
715 				goto out;
716 
717 		iopte_free(iopte);
718 		nent = 1; /* for the next L1 entry */
719 	} else {
720 		bytes = IOPGD_SIZE;
721 		if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
722 			nent *= 16;
723 			/* rewind to the 1st entry */
724 			iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
725 		}
726 		bytes *= nent;
727 	}
728 	memset(iopgd, 0, nent * sizeof(*iopgd));
729 	flush_iopgd_range(iopgd, iopgd + (nent - 1) * sizeof(*iopgd));
730 out:
731 	return bytes;
732 }
733 
734 /**
735  * iopgtable_clear_entry - Remove an iommu pte entry
736  * @obj:	target iommu
737  * @da:		iommu device virtual address
738  **/
739 static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
740 {
741 	size_t bytes;
742 
743 	spin_lock(&obj->page_table_lock);
744 
745 	bytes = iopgtable_clear_entry_core(obj, da);
746 	flush_iotlb_page(obj, da);
747 
748 	spin_unlock(&obj->page_table_lock);
749 
750 	return bytes;
751 }
752 
753 static void iopgtable_clear_entry_all(struct omap_iommu *obj)
754 {
755 	int i;
756 
757 	spin_lock(&obj->page_table_lock);
758 
759 	for (i = 0; i < PTRS_PER_IOPGD; i++) {
760 		u32 da;
761 		u32 *iopgd;
762 
763 		da = i << IOPGD_SHIFT;
764 		iopgd = iopgd_offset(obj, da);
765 
766 		if (!*iopgd)
767 			continue;
768 
769 		if (iopgd_is_table(*iopgd))
770 			iopte_free(iopte_offset(iopgd, 0));
771 
772 		*iopgd = 0;
773 		flush_iopgd_range(iopgd, iopgd);
774 	}
775 
776 	flush_iotlb_all(obj);
777 
778 	spin_unlock(&obj->page_table_lock);
779 }
780 
781 /*
782  *	Device IOMMU generic operations
783  */
784 static irqreturn_t iommu_fault_handler(int irq, void *data)
785 {
786 	u32 da, errs;
787 	u32 *iopgd, *iopte;
788 	struct omap_iommu *obj = data;
789 	struct iommu_domain *domain = obj->domain;
790 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
791 
792 	if (!omap_domain->iommu_dev)
793 		return IRQ_NONE;
794 
795 	errs = iommu_report_fault(obj, &da);
796 	if (errs == 0)
797 		return IRQ_HANDLED;
798 
799 	/* Fault callback or TLB/PTE Dynamic loading */
800 	if (!report_iommu_fault(domain, obj->dev, da, 0))
801 		return IRQ_HANDLED;
802 
803 	iommu_disable(obj);
804 
805 	iopgd = iopgd_offset(obj, da);
806 
807 	if (!iopgd_is_table(*iopgd)) {
808 		dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
809 			obj->name, errs, da, iopgd, *iopgd);
810 		return IRQ_NONE;
811 	}
812 
813 	iopte = iopte_offset(iopgd, da);
814 
815 	dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
816 		obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
817 
818 	return IRQ_NONE;
819 }
820 
821 static int device_match_by_alias(struct device *dev, void *data)
822 {
823 	struct omap_iommu *obj = to_iommu(dev);
824 	const char *name = data;
825 
826 	pr_debug("%s: %s %s\n", __func__, obj->name, name);
827 
828 	return strcmp(obj->name, name) == 0;
829 }
830 
831 /**
832  * omap_iommu_attach() - attach iommu device to an iommu domain
833  * @name:	name of target omap iommu device
834  * @iopgd:	page table
835  **/
836 static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
837 {
838 	int err;
839 	struct device *dev;
840 	struct omap_iommu *obj;
841 
842 	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
843 				 device_match_by_alias);
844 	if (!dev)
845 		return ERR_PTR(-ENODEV);
846 
847 	obj = to_iommu(dev);
848 
849 	spin_lock(&obj->iommu_lock);
850 
851 	obj->iopgd = iopgd;
852 	err = iommu_enable(obj);
853 	if (err)
854 		goto err_enable;
855 	flush_iotlb_all(obj);
856 
857 	spin_unlock(&obj->iommu_lock);
858 
859 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
860 	return obj;
861 
862 err_enable:
863 	spin_unlock(&obj->iommu_lock);
864 	return ERR_PTR(err);
865 }
866 
867 /**
868  * omap_iommu_detach - release iommu device
869  * @obj:	target iommu
870  **/
871 static void omap_iommu_detach(struct omap_iommu *obj)
872 {
873 	if (!obj || IS_ERR(obj))
874 		return;
875 
876 	spin_lock(&obj->iommu_lock);
877 
878 	iommu_disable(obj);
879 	obj->iopgd = NULL;
880 
881 	spin_unlock(&obj->iommu_lock);
882 
883 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
884 }
885 
886 static int omap_iommu_dra7_get_dsp_system_cfg(struct platform_device *pdev,
887 					      struct omap_iommu *obj)
888 {
889 	struct device_node *np = pdev->dev.of_node;
890 	int ret;
891 
892 	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
893 		return 0;
894 
895 	if (!of_property_read_bool(np, "ti,syscon-mmuconfig")) {
896 		dev_err(&pdev->dev, "ti,syscon-mmuconfig property is missing\n");
897 		return -EINVAL;
898 	}
899 
900 	obj->syscfg =
901 		syscon_regmap_lookup_by_phandle(np, "ti,syscon-mmuconfig");
902 	if (IS_ERR(obj->syscfg)) {
903 		/* can fail with -EPROBE_DEFER */
904 		ret = PTR_ERR(obj->syscfg);
905 		return ret;
906 	}
907 
908 	if (of_property_read_u32_index(np, "ti,syscon-mmuconfig", 1,
909 				       &obj->id)) {
910 		dev_err(&pdev->dev, "couldn't get the IOMMU instance id within subsystem\n");
911 		return -EINVAL;
912 	}
913 
914 	if (obj->id != 0 && obj->id != 1) {
915 		dev_err(&pdev->dev, "invalid IOMMU instance id\n");
916 		return -EINVAL;
917 	}
918 
919 	return 0;
920 }
921 
922 /*
923  *	OMAP Device MMU(IOMMU) detection
924  */
925 static int omap_iommu_probe(struct platform_device *pdev)
926 {
927 	int err = -ENODEV;
928 	int irq;
929 	struct omap_iommu *obj;
930 	struct resource *res;
931 	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
932 	struct device_node *of = pdev->dev.of_node;
933 
934 	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
935 	if (!obj)
936 		return -ENOMEM;
937 
938 	if (of) {
939 		obj->name = dev_name(&pdev->dev);
940 		obj->nr_tlb_entries = 32;
941 		err = of_property_read_u32(of, "ti,#tlb-entries",
942 					   &obj->nr_tlb_entries);
943 		if (err && err != -EINVAL)
944 			return err;
945 		if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
946 			return -EINVAL;
947 		if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
948 			obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
949 	} else {
950 		obj->nr_tlb_entries = pdata->nr_tlb_entries;
951 		obj->name = pdata->name;
952 	}
953 
954 	obj->dev = &pdev->dev;
955 	obj->ctx = (void *)obj + sizeof(*obj);
956 
957 	spin_lock_init(&obj->iommu_lock);
958 	spin_lock_init(&obj->page_table_lock);
959 
960 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
961 	obj->regbase = devm_ioremap_resource(obj->dev, res);
962 	if (IS_ERR(obj->regbase))
963 		return PTR_ERR(obj->regbase);
964 
965 	err = omap_iommu_dra7_get_dsp_system_cfg(pdev, obj);
966 	if (err)
967 		return err;
968 
969 	irq = platform_get_irq(pdev, 0);
970 	if (irq < 0)
971 		return -ENODEV;
972 
973 	err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
974 			       dev_name(obj->dev), obj);
975 	if (err < 0)
976 		return err;
977 	platform_set_drvdata(pdev, obj);
978 
979 	pm_runtime_irq_safe(obj->dev);
980 	pm_runtime_enable(obj->dev);
981 
982 	omap_iommu_debugfs_add(obj);
983 
984 	dev_info(&pdev->dev, "%s registered\n", obj->name);
985 	return 0;
986 }
987 
988 static int omap_iommu_remove(struct platform_device *pdev)
989 {
990 	struct omap_iommu *obj = platform_get_drvdata(pdev);
991 
992 	omap_iommu_debugfs_remove(obj);
993 
994 	pm_runtime_disable(obj->dev);
995 
996 	dev_info(&pdev->dev, "%s removed\n", obj->name);
997 	return 0;
998 }
999 
1000 static const struct of_device_id omap_iommu_of_match[] = {
1001 	{ .compatible = "ti,omap2-iommu" },
1002 	{ .compatible = "ti,omap4-iommu" },
1003 	{ .compatible = "ti,dra7-iommu"	},
1004 	{ .compatible = "ti,dra7-dsp-iommu" },
1005 	{},
1006 };
1007 
1008 static struct platform_driver omap_iommu_driver = {
1009 	.probe	= omap_iommu_probe,
1010 	.remove	= omap_iommu_remove,
1011 	.driver	= {
1012 		.name	= "omap-iommu",
1013 		.of_match_table = of_match_ptr(omap_iommu_of_match),
1014 	},
1015 };
1016 
1017 static void iopte_cachep_ctor(void *iopte)
1018 {
1019 	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);
1020 }
1021 
1022 static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
1023 {
1024 	memset(e, 0, sizeof(*e));
1025 
1026 	e->da		= da;
1027 	e->pa		= pa;
1028 	e->valid	= MMU_CAM_V;
1029 	e->pgsz		= pgsz;
1030 	e->endian	= MMU_RAM_ENDIAN_LITTLE;
1031 	e->elsz		= MMU_RAM_ELSZ_8;
1032 	e->mixed	= 0;
1033 
1034 	return iopgsz_to_bytes(e->pgsz);
1035 }
1036 
1037 static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
1038 			  phys_addr_t pa, size_t bytes, int prot)
1039 {
1040 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1041 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1042 	struct device *dev = oiommu->dev;
1043 	struct iotlb_entry e;
1044 	int omap_pgsz;
1045 	u32 ret;
1046 
1047 	omap_pgsz = bytes_to_iopgsz(bytes);
1048 	if (omap_pgsz < 0) {
1049 		dev_err(dev, "invalid size to map: %d\n", bytes);
1050 		return -EINVAL;
1051 	}
1052 
1053 	dev_dbg(dev, "mapping da 0x%lx to pa %pa size 0x%x\n", da, &pa, bytes);
1054 
1055 	iotlb_init_entry(&e, da, pa, omap_pgsz);
1056 
1057 	ret = omap_iopgtable_store_entry(oiommu, &e);
1058 	if (ret)
1059 		dev_err(dev, "omap_iopgtable_store_entry failed: %d\n", ret);
1060 
1061 	return ret;
1062 }
1063 
1064 static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
1065 			       size_t size)
1066 {
1067 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1068 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1069 	struct device *dev = oiommu->dev;
1070 
1071 	dev_dbg(dev, "unmapping da 0x%lx size %u\n", da, size);
1072 
1073 	return iopgtable_clear_entry(oiommu, da);
1074 }
1075 
1076 static int
1077 omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
1078 {
1079 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1080 	struct omap_iommu *oiommu;
1081 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1082 	int ret = 0;
1083 
1084 	if (!arch_data || !arch_data->name) {
1085 		dev_err(dev, "device doesn't have an associated iommu\n");
1086 		return -EINVAL;
1087 	}
1088 
1089 	spin_lock(&omap_domain->lock);
1090 
1091 	/* only a single device is supported per domain for now */
1092 	if (omap_domain->iommu_dev) {
1093 		dev_err(dev, "iommu domain is already attached\n");
1094 		ret = -EBUSY;
1095 		goto out;
1096 	}
1097 
1098 	/* get a handle to and enable the omap iommu */
1099 	oiommu = omap_iommu_attach(arch_data->name, omap_domain->pgtable);
1100 	if (IS_ERR(oiommu)) {
1101 		ret = PTR_ERR(oiommu);
1102 		dev_err(dev, "can't get omap iommu: %d\n", ret);
1103 		goto out;
1104 	}
1105 
1106 	omap_domain->iommu_dev = arch_data->iommu_dev = oiommu;
1107 	omap_domain->dev = dev;
1108 	oiommu->domain = domain;
1109 
1110 out:
1111 	spin_unlock(&omap_domain->lock);
1112 	return ret;
1113 }
1114 
1115 static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
1116 				   struct device *dev)
1117 {
1118 	struct omap_iommu *oiommu = dev_to_omap_iommu(dev);
1119 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1120 
1121 	/* only a single device is supported per domain for now */
1122 	if (omap_domain->iommu_dev != oiommu) {
1123 		dev_err(dev, "invalid iommu device\n");
1124 		return;
1125 	}
1126 
1127 	iopgtable_clear_entry_all(oiommu);
1128 
1129 	omap_iommu_detach(oiommu);
1130 
1131 	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;
1132 	omap_domain->dev = NULL;
1133 	oiommu->domain = NULL;
1134 }
1135 
1136 static void omap_iommu_detach_dev(struct iommu_domain *domain,
1137 				  struct device *dev)
1138 {
1139 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1140 
1141 	spin_lock(&omap_domain->lock);
1142 	_omap_iommu_detach_dev(omap_domain, dev);
1143 	spin_unlock(&omap_domain->lock);
1144 }
1145 
1146 static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
1147 {
1148 	struct omap_iommu_domain *omap_domain;
1149 
1150 	if (type != IOMMU_DOMAIN_UNMANAGED)
1151 		return NULL;
1152 
1153 	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
1154 	if (!omap_domain)
1155 		goto out;
1156 
1157 	omap_domain->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_KERNEL);
1158 	if (!omap_domain->pgtable)
1159 		goto fail_nomem;
1160 
1161 	/*
1162 	 * should never fail, but please keep this around to ensure
1163 	 * we keep the hardware happy
1164 	 */
1165 	if (WARN_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE)))
1166 		goto fail_align;
1167 
1168 	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);
1169 	spin_lock_init(&omap_domain->lock);
1170 
1171 	omap_domain->domain.geometry.aperture_start = 0;
1172 	omap_domain->domain.geometry.aperture_end   = (1ULL << 32) - 1;
1173 	omap_domain->domain.geometry.force_aperture = true;
1174 
1175 	return &omap_domain->domain;
1176 
1177 fail_align:
1178 	kfree(omap_domain->pgtable);
1179 fail_nomem:
1180 	kfree(omap_domain);
1181 out:
1182 	return NULL;
1183 }
1184 
1185 static void omap_iommu_domain_free(struct iommu_domain *domain)
1186 {
1187 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1188 
1189 	/*
1190 	 * An iommu device is still attached
1191 	 * (currently, only one device can be attached) ?
1192 	 */
1193 	if (omap_domain->iommu_dev)
1194 		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
1195 
1196 	kfree(omap_domain->pgtable);
1197 	kfree(omap_domain);
1198 }
1199 
1200 static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
1201 					   dma_addr_t da)
1202 {
1203 	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1204 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1205 	struct device *dev = oiommu->dev;
1206 	u32 *pgd, *pte;
1207 	phys_addr_t ret = 0;
1208 
1209 	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
1210 
1211 	if (pte) {
1212 		if (iopte_is_small(*pte))
1213 			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
1214 		else if (iopte_is_large(*pte))
1215 			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
1216 		else
1217 			dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
1218 				(unsigned long long)da);
1219 	} else {
1220 		if (iopgd_is_section(*pgd))
1221 			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
1222 		else if (iopgd_is_super(*pgd))
1223 			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
1224 		else
1225 			dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
1226 				(unsigned long long)da);
1227 	}
1228 
1229 	return ret;
1230 }
1231 
1232 static int omap_iommu_add_device(struct device *dev)
1233 {
1234 	struct omap_iommu_arch_data *arch_data;
1235 	struct device_node *np;
1236 	struct platform_device *pdev;
1237 
1238 	/*
1239 	 * Allocate the archdata iommu structure for DT-based devices.
1240 	 *
1241 	 * TODO: Simplify this when removing non-DT support completely from the
1242 	 * IOMMU users.
1243 	 */
1244 	if (!dev->of_node)
1245 		return 0;
1246 
1247 	np = of_parse_phandle(dev->of_node, "iommus", 0);
1248 	if (!np)
1249 		return 0;
1250 
1251 	pdev = of_find_device_by_node(np);
1252 	if (WARN_ON(!pdev)) {
1253 		of_node_put(np);
1254 		return -EINVAL;
1255 	}
1256 
1257 	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
1258 	if (!arch_data) {
1259 		of_node_put(np);
1260 		return -ENOMEM;
1261 	}
1262 
1263 	arch_data->name = kstrdup(dev_name(&pdev->dev), GFP_KERNEL);
1264 	dev->archdata.iommu = arch_data;
1265 
1266 	of_node_put(np);
1267 
1268 	return 0;
1269 }
1270 
1271 static void omap_iommu_remove_device(struct device *dev)
1272 {
1273 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1274 
1275 	if (!dev->of_node || !arch_data)
1276 		return;
1277 
1278 	kfree(arch_data->name);
1279 	kfree(arch_data);
1280 }
1281 
1282 static const struct iommu_ops omap_iommu_ops = {
1283 	.domain_alloc	= omap_iommu_domain_alloc,
1284 	.domain_free	= omap_iommu_domain_free,
1285 	.attach_dev	= omap_iommu_attach_dev,
1286 	.detach_dev	= omap_iommu_detach_dev,
1287 	.map		= omap_iommu_map,
1288 	.unmap		= omap_iommu_unmap,
1289 	.map_sg		= default_iommu_map_sg,
1290 	.iova_to_phys	= omap_iommu_iova_to_phys,
1291 	.add_device	= omap_iommu_add_device,
1292 	.remove_device	= omap_iommu_remove_device,
1293 	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
1294 };
1295 
1296 static int __init omap_iommu_init(void)
1297 {
1298 	struct kmem_cache *p;
1299 	const unsigned long flags = SLAB_HWCACHE_ALIGN;
1300 	size_t align = 1 << 10; /* L2 pagetable alignement */
1301 	struct device_node *np;
1302 
1303 	np = of_find_matching_node(NULL, omap_iommu_of_match);
1304 	if (!np)
1305 		return 0;
1306 
1307 	of_node_put(np);
1308 
1309 	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
1310 			      iopte_cachep_ctor);
1311 	if (!p)
1312 		return -ENOMEM;
1313 	iopte_cachep = p;
1314 
1315 	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
1316 
1317 	omap_iommu_debugfs_init();
1318 
1319 	return platform_driver_register(&omap_iommu_driver);
1320 }
1321 subsys_initcall(omap_iommu_init);
1322 /* must be ready before omap3isp is probed */
1323