xref: /openbmc/linux/drivers/iommu/omap-iommu.c (revision 588b48ca)
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/module.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/ioport.h>
19 #include <linux/platform_device.h>
20 #include <linux/iommu.h>
21 #include <linux/omap-iommu.h>
22 #include <linux/mutex.h>
23 #include <linux/spinlock.h>
24 #include <linux/io.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/of.h>
27 #include <linux/of_iommu.h>
28 #include <linux/of_irq.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 #define for_each_iotlb_cr(obj, n, __i, cr)				\
41 	for (__i = 0;							\
42 	     (__i < (n)) && (cr = __iotlb_read_cr((obj), __i), true);	\
43 	     __i++)
44 
45 /* bitmap of the page sizes currently supported */
46 #define OMAP_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
47 
48 /**
49  * struct omap_iommu_domain - omap iommu domain
50  * @pgtable:	the page table
51  * @iommu_dev:	an omap iommu device attached to this domain. only a single
52  *		iommu device can be attached for now.
53  * @dev:	Device using this domain.
54  * @lock:	domain lock, should be taken when attaching/detaching
55  */
56 struct omap_iommu_domain {
57 	u32 *pgtable;
58 	struct omap_iommu *iommu_dev;
59 	struct device *dev;
60 	spinlock_t lock;
61 };
62 
63 #define MMU_LOCK_BASE_SHIFT	10
64 #define MMU_LOCK_BASE_MASK	(0x1f << MMU_LOCK_BASE_SHIFT)
65 #define MMU_LOCK_BASE(x)	\
66 	((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
67 
68 #define MMU_LOCK_VICT_SHIFT	4
69 #define MMU_LOCK_VICT_MASK	(0x1f << MMU_LOCK_VICT_SHIFT)
70 #define MMU_LOCK_VICT(x)	\
71 	((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
72 
73 struct iotlb_lock {
74 	short base;
75 	short vict;
76 };
77 
78 /* accommodate the difference between omap1 and omap2/3 */
79 static const struct iommu_functions *arch_iommu;
80 
81 static struct platform_driver omap_iommu_driver;
82 static struct kmem_cache *iopte_cachep;
83 
84 /**
85  * omap_install_iommu_arch - Install archtecure specific iommu functions
86  * @ops:	a pointer to architecture specific iommu functions
87  *
88  * There are several kind of iommu algorithm(tlb, pagetable) among
89  * omap series. This interface installs such an iommu algorighm.
90  **/
91 int omap_install_iommu_arch(const struct iommu_functions *ops)
92 {
93 	if (arch_iommu)
94 		return -EBUSY;
95 
96 	arch_iommu = ops;
97 	return 0;
98 }
99 EXPORT_SYMBOL_GPL(omap_install_iommu_arch);
100 
101 /**
102  * omap_uninstall_iommu_arch - Uninstall archtecure specific iommu functions
103  * @ops:	a pointer to architecture specific iommu functions
104  *
105  * This interface uninstalls the iommu algorighm installed previously.
106  **/
107 void omap_uninstall_iommu_arch(const struct iommu_functions *ops)
108 {
109 	if (arch_iommu != ops)
110 		pr_err("%s: not your arch\n", __func__);
111 
112 	arch_iommu = NULL;
113 }
114 EXPORT_SYMBOL_GPL(omap_uninstall_iommu_arch);
115 
116 /**
117  * omap_iommu_save_ctx - Save registers for pm off-mode support
118  * @dev:	client device
119  **/
120 void omap_iommu_save_ctx(struct device *dev)
121 {
122 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
123 
124 	arch_iommu->save_ctx(obj);
125 }
126 EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
127 
128 /**
129  * omap_iommu_restore_ctx - Restore registers for pm off-mode support
130  * @dev:	client device
131  **/
132 void omap_iommu_restore_ctx(struct device *dev)
133 {
134 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
135 
136 	arch_iommu->restore_ctx(obj);
137 }
138 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
139 
140 /**
141  * omap_iommu_arch_version - Return running iommu arch version
142  **/
143 u32 omap_iommu_arch_version(void)
144 {
145 	return arch_iommu->version;
146 }
147 EXPORT_SYMBOL_GPL(omap_iommu_arch_version);
148 
149 static int iommu_enable(struct omap_iommu *obj)
150 {
151 	int err;
152 	struct platform_device *pdev = to_platform_device(obj->dev);
153 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
154 
155 	if (!arch_iommu)
156 		return -ENODEV;
157 
158 	if (pdata && pdata->deassert_reset) {
159 		err = pdata->deassert_reset(pdev, pdata->reset_name);
160 		if (err) {
161 			dev_err(obj->dev, "deassert_reset failed: %d\n", err);
162 			return err;
163 		}
164 	}
165 
166 	pm_runtime_get_sync(obj->dev);
167 
168 	err = arch_iommu->enable(obj);
169 
170 	return err;
171 }
172 
173 static void iommu_disable(struct omap_iommu *obj)
174 {
175 	struct platform_device *pdev = to_platform_device(obj->dev);
176 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
177 
178 	arch_iommu->disable(obj);
179 
180 	pm_runtime_put_sync(obj->dev);
181 
182 	if (pdata && pdata->assert_reset)
183 		pdata->assert_reset(pdev, pdata->reset_name);
184 }
185 
186 /*
187  *	TLB operations
188  */
189 void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
190 {
191 	BUG_ON(!cr || !e);
192 
193 	arch_iommu->cr_to_e(cr, e);
194 }
195 EXPORT_SYMBOL_GPL(omap_iotlb_cr_to_e);
196 
197 static inline int iotlb_cr_valid(struct cr_regs *cr)
198 {
199 	if (!cr)
200 		return -EINVAL;
201 
202 	return arch_iommu->cr_valid(cr);
203 }
204 
205 static inline struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
206 					     struct iotlb_entry *e)
207 {
208 	if (!e)
209 		return NULL;
210 
211 	return arch_iommu->alloc_cr(obj, e);
212 }
213 
214 static u32 iotlb_cr_to_virt(struct cr_regs *cr)
215 {
216 	return arch_iommu->cr_to_virt(cr);
217 }
218 
219 static u32 get_iopte_attr(struct iotlb_entry *e)
220 {
221 	return arch_iommu->get_pte_attr(e);
222 }
223 
224 static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
225 {
226 	return arch_iommu->fault_isr(obj, da);
227 }
228 
229 static void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
230 {
231 	u32 val;
232 
233 	val = iommu_read_reg(obj, MMU_LOCK);
234 
235 	l->base = MMU_LOCK_BASE(val);
236 	l->vict = MMU_LOCK_VICT(val);
237 
238 }
239 
240 static void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
241 {
242 	u32 val;
243 
244 	val = (l->base << MMU_LOCK_BASE_SHIFT);
245 	val |= (l->vict << MMU_LOCK_VICT_SHIFT);
246 
247 	iommu_write_reg(obj, val, MMU_LOCK);
248 }
249 
250 static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
251 {
252 	arch_iommu->tlb_read_cr(obj, cr);
253 }
254 
255 static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
256 {
257 	arch_iommu->tlb_load_cr(obj, cr);
258 
259 	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
260 	iommu_write_reg(obj, 1, MMU_LD_TLB);
261 }
262 
263 /**
264  * iotlb_dump_cr - Dump an iommu tlb entry into buf
265  * @obj:	target iommu
266  * @cr:		contents of cam and ram register
267  * @buf:	output buffer
268  **/
269 static inline ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
270 				    char *buf)
271 {
272 	BUG_ON(!cr || !buf);
273 
274 	return arch_iommu->dump_cr(obj, cr, buf);
275 }
276 
277 /* only used in iotlb iteration for-loop */
278 static struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
279 {
280 	struct cr_regs cr;
281 	struct iotlb_lock l;
282 
283 	iotlb_lock_get(obj, &l);
284 	l.vict = n;
285 	iotlb_lock_set(obj, &l);
286 	iotlb_read_cr(obj, &cr);
287 
288 	return cr;
289 }
290 
291 /**
292  * load_iotlb_entry - Set an iommu tlb entry
293  * @obj:	target iommu
294  * @e:		an iommu tlb entry info
295  **/
296 #ifdef PREFETCH_IOTLB
297 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
298 {
299 	int err = 0;
300 	struct iotlb_lock l;
301 	struct cr_regs *cr;
302 
303 	if (!obj || !obj->nr_tlb_entries || !e)
304 		return -EINVAL;
305 
306 	pm_runtime_get_sync(obj->dev);
307 
308 	iotlb_lock_get(obj, &l);
309 	if (l.base == obj->nr_tlb_entries) {
310 		dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
311 		err = -EBUSY;
312 		goto out;
313 	}
314 	if (!e->prsvd) {
315 		int i;
316 		struct cr_regs tmp;
317 
318 		for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
319 			if (!iotlb_cr_valid(&tmp))
320 				break;
321 
322 		if (i == obj->nr_tlb_entries) {
323 			dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
324 			err = -EBUSY;
325 			goto out;
326 		}
327 
328 		iotlb_lock_get(obj, &l);
329 	} else {
330 		l.vict = l.base;
331 		iotlb_lock_set(obj, &l);
332 	}
333 
334 	cr = iotlb_alloc_cr(obj, e);
335 	if (IS_ERR(cr)) {
336 		pm_runtime_put_sync(obj->dev);
337 		return PTR_ERR(cr);
338 	}
339 
340 	iotlb_load_cr(obj, cr);
341 	kfree(cr);
342 
343 	if (e->prsvd)
344 		l.base++;
345 	/* increment victim for next tlb load */
346 	if (++l.vict == obj->nr_tlb_entries)
347 		l.vict = l.base;
348 	iotlb_lock_set(obj, &l);
349 out:
350 	pm_runtime_put_sync(obj->dev);
351 	return err;
352 }
353 
354 #else /* !PREFETCH_IOTLB */
355 
356 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
357 {
358 	return 0;
359 }
360 
361 #endif /* !PREFETCH_IOTLB */
362 
363 static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
364 {
365 	return load_iotlb_entry(obj, e);
366 }
367 
368 /**
369  * flush_iotlb_page - Clear an iommu tlb entry
370  * @obj:	target iommu
371  * @da:		iommu device virtual address
372  *
373  * Clear an iommu tlb entry which includes 'da' address.
374  **/
375 static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
376 {
377 	int i;
378 	struct cr_regs cr;
379 
380 	pm_runtime_get_sync(obj->dev);
381 
382 	for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
383 		u32 start;
384 		size_t bytes;
385 
386 		if (!iotlb_cr_valid(&cr))
387 			continue;
388 
389 		start = iotlb_cr_to_virt(&cr);
390 		bytes = iopgsz_to_bytes(cr.cam & 3);
391 
392 		if ((start <= da) && (da < start + bytes)) {
393 			dev_dbg(obj->dev, "%s: %08x<=%08x(%x)\n",
394 				__func__, start, da, bytes);
395 			iotlb_load_cr(obj, &cr);
396 			iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
397 			break;
398 		}
399 	}
400 	pm_runtime_put_sync(obj->dev);
401 
402 	if (i == obj->nr_tlb_entries)
403 		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
404 }
405 
406 /**
407  * flush_iotlb_all - Clear all iommu tlb entries
408  * @obj:	target iommu
409  **/
410 static void flush_iotlb_all(struct omap_iommu *obj)
411 {
412 	struct iotlb_lock l;
413 
414 	pm_runtime_get_sync(obj->dev);
415 
416 	l.base = 0;
417 	l.vict = 0;
418 	iotlb_lock_set(obj, &l);
419 
420 	iommu_write_reg(obj, 1, MMU_GFLUSH);
421 
422 	pm_runtime_put_sync(obj->dev);
423 }
424 
425 #if defined(CONFIG_OMAP_IOMMU_DEBUG) || defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
426 
427 ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t bytes)
428 {
429 	if (!obj || !buf)
430 		return -EINVAL;
431 
432 	pm_runtime_get_sync(obj->dev);
433 
434 	bytes = arch_iommu->dump_ctx(obj, buf, bytes);
435 
436 	pm_runtime_put_sync(obj->dev);
437 
438 	return bytes;
439 }
440 EXPORT_SYMBOL_GPL(omap_iommu_dump_ctx);
441 
442 static int
443 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
444 {
445 	int i;
446 	struct iotlb_lock saved;
447 	struct cr_regs tmp;
448 	struct cr_regs *p = crs;
449 
450 	pm_runtime_get_sync(obj->dev);
451 	iotlb_lock_get(obj, &saved);
452 
453 	for_each_iotlb_cr(obj, num, i, tmp) {
454 		if (!iotlb_cr_valid(&tmp))
455 			continue;
456 		*p++ = tmp;
457 	}
458 
459 	iotlb_lock_set(obj, &saved);
460 	pm_runtime_put_sync(obj->dev);
461 
462 	return  p - crs;
463 }
464 
465 /**
466  * omap_dump_tlb_entries - dump cr arrays to given buffer
467  * @obj:	target iommu
468  * @buf:	output buffer
469  **/
470 size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t bytes)
471 {
472 	int i, num;
473 	struct cr_regs *cr;
474 	char *p = buf;
475 
476 	num = bytes / sizeof(*cr);
477 	num = min(obj->nr_tlb_entries, num);
478 
479 	cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
480 	if (!cr)
481 		return 0;
482 
483 	num = __dump_tlb_entries(obj, cr, num);
484 	for (i = 0; i < num; i++)
485 		p += iotlb_dump_cr(obj, cr + i, p);
486 	kfree(cr);
487 
488 	return p - buf;
489 }
490 EXPORT_SYMBOL_GPL(omap_dump_tlb_entries);
491 
492 int omap_foreach_iommu_device(void *data, int (*fn)(struct device *, void *))
493 {
494 	return driver_for_each_device(&omap_iommu_driver.driver,
495 				      NULL, data, fn);
496 }
497 EXPORT_SYMBOL_GPL(omap_foreach_iommu_device);
498 
499 #endif /* CONFIG_OMAP_IOMMU_DEBUG_MODULE */
500 
501 /*
502  *	H/W pagetable operations
503  */
504 static void flush_iopgd_range(u32 *first, u32 *last)
505 {
506 	/* FIXME: L2 cache should be taken care of if it exists */
507 	do {
508 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pgd"
509 		    : : "r" (first));
510 		first += L1_CACHE_BYTES / sizeof(*first);
511 	} while (first <= last);
512 }
513 
514 static void flush_iopte_range(u32 *first, u32 *last)
515 {
516 	/* FIXME: L2 cache should be taken care of if it exists */
517 	do {
518 		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pte"
519 		    : : "r" (first));
520 		first += L1_CACHE_BYTES / sizeof(*first);
521 	} while (first <= last);
522 }
523 
524 static void iopte_free(u32 *iopte)
525 {
526 	/* Note: freed iopte's must be clean ready for re-use */
527 	if (iopte)
528 		kmem_cache_free(iopte_cachep, iopte);
529 }
530 
531 static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd, u32 da)
532 {
533 	u32 *iopte;
534 
535 	/* a table has already existed */
536 	if (*iopgd)
537 		goto pte_ready;
538 
539 	/*
540 	 * do the allocation outside the page table lock
541 	 */
542 	spin_unlock(&obj->page_table_lock);
543 	iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
544 	spin_lock(&obj->page_table_lock);
545 
546 	if (!*iopgd) {
547 		if (!iopte)
548 			return ERR_PTR(-ENOMEM);
549 
550 		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
551 		flush_iopgd_range(iopgd, iopgd);
552 
553 		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
554 	} else {
555 		/* We raced, free the reduniovant table */
556 		iopte_free(iopte);
557 	}
558 
559 pte_ready:
560 	iopte = iopte_offset(iopgd, da);
561 
562 	dev_vdbg(obj->dev,
563 		 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
564 		 __func__, da, iopgd, *iopgd, iopte, *iopte);
565 
566 	return iopte;
567 }
568 
569 static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
570 {
571 	u32 *iopgd = iopgd_offset(obj, da);
572 
573 	if ((da | pa) & ~IOSECTION_MASK) {
574 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
575 			__func__, da, pa, IOSECTION_SIZE);
576 		return -EINVAL;
577 	}
578 
579 	*iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
580 	flush_iopgd_range(iopgd, iopgd);
581 	return 0;
582 }
583 
584 static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
585 {
586 	u32 *iopgd = iopgd_offset(obj, da);
587 	int i;
588 
589 	if ((da | pa) & ~IOSUPER_MASK) {
590 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
591 			__func__, da, pa, IOSUPER_SIZE);
592 		return -EINVAL;
593 	}
594 
595 	for (i = 0; i < 16; i++)
596 		*(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
597 	flush_iopgd_range(iopgd, iopgd + 15);
598 	return 0;
599 }
600 
601 static int iopte_alloc_page(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
602 {
603 	u32 *iopgd = iopgd_offset(obj, da);
604 	u32 *iopte = iopte_alloc(obj, iopgd, da);
605 
606 	if (IS_ERR(iopte))
607 		return PTR_ERR(iopte);
608 
609 	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
610 	flush_iopte_range(iopte, iopte);
611 
612 	dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
613 		 __func__, da, pa, iopte, *iopte);
614 
615 	return 0;
616 }
617 
618 static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
619 {
620 	u32 *iopgd = iopgd_offset(obj, da);
621 	u32 *iopte = iopte_alloc(obj, iopgd, da);
622 	int i;
623 
624 	if ((da | pa) & ~IOLARGE_MASK) {
625 		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
626 			__func__, da, pa, IOLARGE_SIZE);
627 		return -EINVAL;
628 	}
629 
630 	if (IS_ERR(iopte))
631 		return PTR_ERR(iopte);
632 
633 	for (i = 0; i < 16; i++)
634 		*(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
635 	flush_iopte_range(iopte, iopte + 15);
636 	return 0;
637 }
638 
639 static int
640 iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
641 {
642 	int (*fn)(struct omap_iommu *, u32, u32, u32);
643 	u32 prot;
644 	int err;
645 
646 	if (!obj || !e)
647 		return -EINVAL;
648 
649 	switch (e->pgsz) {
650 	case MMU_CAM_PGSZ_16M:
651 		fn = iopgd_alloc_super;
652 		break;
653 	case MMU_CAM_PGSZ_1M:
654 		fn = iopgd_alloc_section;
655 		break;
656 	case MMU_CAM_PGSZ_64K:
657 		fn = iopte_alloc_large;
658 		break;
659 	case MMU_CAM_PGSZ_4K:
660 		fn = iopte_alloc_page;
661 		break;
662 	default:
663 		fn = NULL;
664 		BUG();
665 		break;
666 	}
667 
668 	prot = get_iopte_attr(e);
669 
670 	spin_lock(&obj->page_table_lock);
671 	err = fn(obj, e->da, e->pa, prot);
672 	spin_unlock(&obj->page_table_lock);
673 
674 	return err;
675 }
676 
677 /**
678  * omap_iopgtable_store_entry - Make an iommu pte entry
679  * @obj:	target iommu
680  * @e:		an iommu tlb entry info
681  **/
682 int omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
683 {
684 	int err;
685 
686 	flush_iotlb_page(obj, e->da);
687 	err = iopgtable_store_entry_core(obj, e);
688 	if (!err)
689 		prefetch_iotlb_entry(obj, e);
690 	return err;
691 }
692 EXPORT_SYMBOL_GPL(omap_iopgtable_store_entry);
693 
694 /**
695  * iopgtable_lookup_entry - Lookup an iommu pte entry
696  * @obj:	target iommu
697  * @da:		iommu device virtual address
698  * @ppgd:	iommu pgd entry pointer to be returned
699  * @ppte:	iommu pte entry pointer to be returned
700  **/
701 static void
702 iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
703 {
704 	u32 *iopgd, *iopte = NULL;
705 
706 	iopgd = iopgd_offset(obj, da);
707 	if (!*iopgd)
708 		goto out;
709 
710 	if (iopgd_is_table(*iopgd))
711 		iopte = iopte_offset(iopgd, da);
712 out:
713 	*ppgd = iopgd;
714 	*ppte = iopte;
715 }
716 
717 static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
718 {
719 	size_t bytes;
720 	u32 *iopgd = iopgd_offset(obj, da);
721 	int nent = 1;
722 
723 	if (!*iopgd)
724 		return 0;
725 
726 	if (iopgd_is_table(*iopgd)) {
727 		int i;
728 		u32 *iopte = iopte_offset(iopgd, da);
729 
730 		bytes = IOPTE_SIZE;
731 		if (*iopte & IOPTE_LARGE) {
732 			nent *= 16;
733 			/* rewind to the 1st entry */
734 			iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
735 		}
736 		bytes *= nent;
737 		memset(iopte, 0, nent * sizeof(*iopte));
738 		flush_iopte_range(iopte, iopte + (nent - 1) * sizeof(*iopte));
739 
740 		/*
741 		 * do table walk to check if this table is necessary or not
742 		 */
743 		iopte = iopte_offset(iopgd, 0);
744 		for (i = 0; i < PTRS_PER_IOPTE; i++)
745 			if (iopte[i])
746 				goto out;
747 
748 		iopte_free(iopte);
749 		nent = 1; /* for the next L1 entry */
750 	} else {
751 		bytes = IOPGD_SIZE;
752 		if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
753 			nent *= 16;
754 			/* rewind to the 1st entry */
755 			iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
756 		}
757 		bytes *= nent;
758 	}
759 	memset(iopgd, 0, nent * sizeof(*iopgd));
760 	flush_iopgd_range(iopgd, iopgd + (nent - 1) * sizeof(*iopgd));
761 out:
762 	return bytes;
763 }
764 
765 /**
766  * iopgtable_clear_entry - Remove an iommu pte entry
767  * @obj:	target iommu
768  * @da:		iommu device virtual address
769  **/
770 static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
771 {
772 	size_t bytes;
773 
774 	spin_lock(&obj->page_table_lock);
775 
776 	bytes = iopgtable_clear_entry_core(obj, da);
777 	flush_iotlb_page(obj, da);
778 
779 	spin_unlock(&obj->page_table_lock);
780 
781 	return bytes;
782 }
783 
784 static void iopgtable_clear_entry_all(struct omap_iommu *obj)
785 {
786 	int i;
787 
788 	spin_lock(&obj->page_table_lock);
789 
790 	for (i = 0; i < PTRS_PER_IOPGD; i++) {
791 		u32 da;
792 		u32 *iopgd;
793 
794 		da = i << IOPGD_SHIFT;
795 		iopgd = iopgd_offset(obj, da);
796 
797 		if (!*iopgd)
798 			continue;
799 
800 		if (iopgd_is_table(*iopgd))
801 			iopte_free(iopte_offset(iopgd, 0));
802 
803 		*iopgd = 0;
804 		flush_iopgd_range(iopgd, iopgd);
805 	}
806 
807 	flush_iotlb_all(obj);
808 
809 	spin_unlock(&obj->page_table_lock);
810 }
811 
812 /*
813  *	Device IOMMU generic operations
814  */
815 static irqreturn_t iommu_fault_handler(int irq, void *data)
816 {
817 	u32 da, errs;
818 	u32 *iopgd, *iopte;
819 	struct omap_iommu *obj = data;
820 	struct iommu_domain *domain = obj->domain;
821 
822 	if (!obj->refcount)
823 		return IRQ_NONE;
824 
825 	errs = iommu_report_fault(obj, &da);
826 	if (errs == 0)
827 		return IRQ_HANDLED;
828 
829 	/* Fault callback or TLB/PTE Dynamic loading */
830 	if (!report_iommu_fault(domain, obj->dev, da, 0))
831 		return IRQ_HANDLED;
832 
833 	iommu_disable(obj);
834 
835 	iopgd = iopgd_offset(obj, da);
836 
837 	if (!iopgd_is_table(*iopgd)) {
838 		dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
839 				obj->name, errs, da, iopgd, *iopgd);
840 		return IRQ_NONE;
841 	}
842 
843 	iopte = iopte_offset(iopgd, da);
844 
845 	dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
846 			obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
847 
848 	return IRQ_NONE;
849 }
850 
851 static int device_match_by_alias(struct device *dev, void *data)
852 {
853 	struct omap_iommu *obj = to_iommu(dev);
854 	const char *name = data;
855 
856 	pr_debug("%s: %s %s\n", __func__, obj->name, name);
857 
858 	return strcmp(obj->name, name) == 0;
859 }
860 
861 /**
862  * omap_iommu_attach() - attach iommu device to an iommu domain
863  * @name:	name of target omap iommu device
864  * @iopgd:	page table
865  **/
866 static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
867 {
868 	int err;
869 	struct device *dev;
870 	struct omap_iommu *obj;
871 
872 	dev = driver_find_device(&omap_iommu_driver.driver, NULL,
873 				(void *)name,
874 				device_match_by_alias);
875 	if (!dev)
876 		return ERR_PTR(-ENODEV);
877 
878 	obj = to_iommu(dev);
879 
880 	spin_lock(&obj->iommu_lock);
881 
882 	/* an iommu device can only be attached once */
883 	if (++obj->refcount > 1) {
884 		dev_err(dev, "%s: already attached!\n", obj->name);
885 		err = -EBUSY;
886 		goto err_enable;
887 	}
888 
889 	obj->iopgd = iopgd;
890 	err = iommu_enable(obj);
891 	if (err)
892 		goto err_enable;
893 	flush_iotlb_all(obj);
894 
895 	if (!try_module_get(obj->owner)) {
896 		err = -ENODEV;
897 		goto err_module;
898 	}
899 
900 	spin_unlock(&obj->iommu_lock);
901 
902 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
903 	return obj;
904 
905 err_module:
906 	if (obj->refcount == 1)
907 		iommu_disable(obj);
908 err_enable:
909 	obj->refcount--;
910 	spin_unlock(&obj->iommu_lock);
911 	return ERR_PTR(err);
912 }
913 
914 /**
915  * omap_iommu_detach - release iommu device
916  * @obj:	target iommu
917  **/
918 static void omap_iommu_detach(struct omap_iommu *obj)
919 {
920 	if (!obj || IS_ERR(obj))
921 		return;
922 
923 	spin_lock(&obj->iommu_lock);
924 
925 	if (--obj->refcount == 0)
926 		iommu_disable(obj);
927 
928 	module_put(obj->owner);
929 
930 	obj->iopgd = NULL;
931 
932 	spin_unlock(&obj->iommu_lock);
933 
934 	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
935 }
936 
937 /*
938  *	OMAP Device MMU(IOMMU) detection
939  */
940 static int omap_iommu_probe(struct platform_device *pdev)
941 {
942 	int err = -ENODEV;
943 	int irq;
944 	struct omap_iommu *obj;
945 	struct resource *res;
946 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
947 	struct device_node *of = pdev->dev.of_node;
948 
949 	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
950 	if (!obj)
951 		return -ENOMEM;
952 
953 	if (of) {
954 		obj->name = dev_name(&pdev->dev);
955 		obj->nr_tlb_entries = 32;
956 		err = of_property_read_u32(of, "ti,#tlb-entries",
957 					   &obj->nr_tlb_entries);
958 		if (err && err != -EINVAL)
959 			return err;
960 		if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
961 			return -EINVAL;
962 		if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
963 			obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
964 	} else {
965 		obj->nr_tlb_entries = pdata->nr_tlb_entries;
966 		obj->name = pdata->name;
967 	}
968 
969 	obj->dev = &pdev->dev;
970 	obj->ctx = (void *)obj + sizeof(*obj);
971 
972 	spin_lock_init(&obj->iommu_lock);
973 	spin_lock_init(&obj->page_table_lock);
974 
975 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
976 	obj->regbase = devm_ioremap_resource(obj->dev, res);
977 	if (IS_ERR(obj->regbase))
978 		return PTR_ERR(obj->regbase);
979 
980 	irq = platform_get_irq(pdev, 0);
981 	if (irq < 0)
982 		return -ENODEV;
983 
984 	err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
985 			       dev_name(obj->dev), obj);
986 	if (err < 0)
987 		return err;
988 	platform_set_drvdata(pdev, obj);
989 
990 	pm_runtime_irq_safe(obj->dev);
991 	pm_runtime_enable(obj->dev);
992 
993 	dev_info(&pdev->dev, "%s registered\n", obj->name);
994 	return 0;
995 }
996 
997 static int omap_iommu_remove(struct platform_device *pdev)
998 {
999 	struct omap_iommu *obj = platform_get_drvdata(pdev);
1000 
1001 	iopgtable_clear_entry_all(obj);
1002 
1003 	pm_runtime_disable(obj->dev);
1004 
1005 	dev_info(&pdev->dev, "%s removed\n", obj->name);
1006 	return 0;
1007 }
1008 
1009 static struct of_device_id omap_iommu_of_match[] = {
1010 	{ .compatible = "ti,omap2-iommu" },
1011 	{ .compatible = "ti,omap4-iommu" },
1012 	{ .compatible = "ti,dra7-iommu"	},
1013 	{},
1014 };
1015 MODULE_DEVICE_TABLE(of, omap_iommu_of_match);
1016 
1017 static struct platform_driver omap_iommu_driver = {
1018 	.probe	= omap_iommu_probe,
1019 	.remove	= omap_iommu_remove,
1020 	.driver	= {
1021 		.name	= "omap-iommu",
1022 		.of_match_table = of_match_ptr(omap_iommu_of_match),
1023 	},
1024 };
1025 
1026 static void iopte_cachep_ctor(void *iopte)
1027 {
1028 	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);
1029 }
1030 
1031 static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
1032 {
1033 	memset(e, 0, sizeof(*e));
1034 
1035 	e->da		= da;
1036 	e->pa		= pa;
1037 	e->valid	= MMU_CAM_V;
1038 	/* FIXME: add OMAP1 support */
1039 	e->pgsz		= pgsz;
1040 	e->endian	= MMU_RAM_ENDIAN_LITTLE;
1041 	e->elsz		= MMU_RAM_ELSZ_8;
1042 	e->mixed	= 0;
1043 
1044 	return iopgsz_to_bytes(e->pgsz);
1045 }
1046 
1047 static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
1048 			 phys_addr_t pa, size_t bytes, int prot)
1049 {
1050 	struct omap_iommu_domain *omap_domain = domain->priv;
1051 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1052 	struct device *dev = oiommu->dev;
1053 	struct iotlb_entry e;
1054 	int omap_pgsz;
1055 	u32 ret;
1056 
1057 	omap_pgsz = bytes_to_iopgsz(bytes);
1058 	if (omap_pgsz < 0) {
1059 		dev_err(dev, "invalid size to map: %d\n", bytes);
1060 		return -EINVAL;
1061 	}
1062 
1063 	dev_dbg(dev, "mapping da 0x%lx to pa 0x%x size 0x%x\n", da, pa, bytes);
1064 
1065 	iotlb_init_entry(&e, da, pa, omap_pgsz);
1066 
1067 	ret = omap_iopgtable_store_entry(oiommu, &e);
1068 	if (ret)
1069 		dev_err(dev, "omap_iopgtable_store_entry failed: %d\n", ret);
1070 
1071 	return ret;
1072 }
1073 
1074 static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
1075 			    size_t size)
1076 {
1077 	struct omap_iommu_domain *omap_domain = domain->priv;
1078 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1079 	struct device *dev = oiommu->dev;
1080 
1081 	dev_dbg(dev, "unmapping da 0x%lx size %u\n", da, size);
1082 
1083 	return iopgtable_clear_entry(oiommu, da);
1084 }
1085 
1086 static int
1087 omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
1088 {
1089 	struct omap_iommu_domain *omap_domain = domain->priv;
1090 	struct omap_iommu *oiommu;
1091 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1092 	int ret = 0;
1093 
1094 	spin_lock(&omap_domain->lock);
1095 
1096 	/* only a single device is supported per domain for now */
1097 	if (omap_domain->iommu_dev) {
1098 		dev_err(dev, "iommu domain is already attached\n");
1099 		ret = -EBUSY;
1100 		goto out;
1101 	}
1102 
1103 	/* get a handle to and enable the omap iommu */
1104 	oiommu = omap_iommu_attach(arch_data->name, omap_domain->pgtable);
1105 	if (IS_ERR(oiommu)) {
1106 		ret = PTR_ERR(oiommu);
1107 		dev_err(dev, "can't get omap iommu: %d\n", ret);
1108 		goto out;
1109 	}
1110 
1111 	omap_domain->iommu_dev = arch_data->iommu_dev = oiommu;
1112 	omap_domain->dev = dev;
1113 	oiommu->domain = domain;
1114 
1115 out:
1116 	spin_unlock(&omap_domain->lock);
1117 	return ret;
1118 }
1119 
1120 static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
1121 			struct device *dev)
1122 {
1123 	struct omap_iommu *oiommu = dev_to_omap_iommu(dev);
1124 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1125 
1126 	/* only a single device is supported per domain for now */
1127 	if (omap_domain->iommu_dev != oiommu) {
1128 		dev_err(dev, "invalid iommu device\n");
1129 		return;
1130 	}
1131 
1132 	iopgtable_clear_entry_all(oiommu);
1133 
1134 	omap_iommu_detach(oiommu);
1135 
1136 	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;
1137 	omap_domain->dev = NULL;
1138 }
1139 
1140 static void omap_iommu_detach_dev(struct iommu_domain *domain,
1141 				 struct device *dev)
1142 {
1143 	struct omap_iommu_domain *omap_domain = domain->priv;
1144 
1145 	spin_lock(&omap_domain->lock);
1146 	_omap_iommu_detach_dev(omap_domain, dev);
1147 	spin_unlock(&omap_domain->lock);
1148 }
1149 
1150 static int omap_iommu_domain_init(struct iommu_domain *domain)
1151 {
1152 	struct omap_iommu_domain *omap_domain;
1153 
1154 	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
1155 	if (!omap_domain) {
1156 		pr_err("kzalloc failed\n");
1157 		goto out;
1158 	}
1159 
1160 	omap_domain->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_KERNEL);
1161 	if (!omap_domain->pgtable) {
1162 		pr_err("kzalloc failed\n");
1163 		goto fail_nomem;
1164 	}
1165 
1166 	/*
1167 	 * should never fail, but please keep this around to ensure
1168 	 * we keep the hardware happy
1169 	 */
1170 	BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));
1171 
1172 	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);
1173 	spin_lock_init(&omap_domain->lock);
1174 
1175 	domain->priv = omap_domain;
1176 
1177 	domain->geometry.aperture_start = 0;
1178 	domain->geometry.aperture_end   = (1ULL << 32) - 1;
1179 	domain->geometry.force_aperture = true;
1180 
1181 	return 0;
1182 
1183 fail_nomem:
1184 	kfree(omap_domain);
1185 out:
1186 	return -ENOMEM;
1187 }
1188 
1189 static void omap_iommu_domain_destroy(struct iommu_domain *domain)
1190 {
1191 	struct omap_iommu_domain *omap_domain = domain->priv;
1192 
1193 	domain->priv = NULL;
1194 
1195 	/*
1196 	 * An iommu device is still attached
1197 	 * (currently, only one device can be attached) ?
1198 	 */
1199 	if (omap_domain->iommu_dev)
1200 		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
1201 
1202 	kfree(omap_domain->pgtable);
1203 	kfree(omap_domain);
1204 }
1205 
1206 static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
1207 					  dma_addr_t da)
1208 {
1209 	struct omap_iommu_domain *omap_domain = domain->priv;
1210 	struct omap_iommu *oiommu = omap_domain->iommu_dev;
1211 	struct device *dev = oiommu->dev;
1212 	u32 *pgd, *pte;
1213 	phys_addr_t ret = 0;
1214 
1215 	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
1216 
1217 	if (pte) {
1218 		if (iopte_is_small(*pte))
1219 			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
1220 		else if (iopte_is_large(*pte))
1221 			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
1222 		else
1223 			dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
1224 							(unsigned long long)da);
1225 	} else {
1226 		if (iopgd_is_section(*pgd))
1227 			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
1228 		else if (iopgd_is_super(*pgd))
1229 			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
1230 		else
1231 			dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
1232 							(unsigned long long)da);
1233 	}
1234 
1235 	return ret;
1236 }
1237 
1238 static int omap_iommu_add_device(struct device *dev)
1239 {
1240 	struct omap_iommu_arch_data *arch_data;
1241 	struct device_node *np;
1242 
1243 	/*
1244 	 * Allocate the archdata iommu structure for DT-based devices.
1245 	 *
1246 	 * TODO: Simplify this when removing non-DT support completely from the
1247 	 * IOMMU users.
1248 	 */
1249 	if (!dev->of_node)
1250 		return 0;
1251 
1252 	np = of_parse_phandle(dev->of_node, "iommus", 0);
1253 	if (!np)
1254 		return 0;
1255 
1256 	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
1257 	if (!arch_data) {
1258 		of_node_put(np);
1259 		return -ENOMEM;
1260 	}
1261 
1262 	arch_data->name = kstrdup(dev_name(dev), GFP_KERNEL);
1263 	dev->archdata.iommu = arch_data;
1264 
1265 	of_node_put(np);
1266 
1267 	return 0;
1268 }
1269 
1270 static void omap_iommu_remove_device(struct device *dev)
1271 {
1272 	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
1273 
1274 	if (!dev->of_node || !arch_data)
1275 		return;
1276 
1277 	kfree(arch_data->name);
1278 	kfree(arch_data);
1279 }
1280 
1281 static const struct iommu_ops omap_iommu_ops = {
1282 	.domain_init	= omap_iommu_domain_init,
1283 	.domain_destroy	= omap_iommu_domain_destroy,
1284 	.attach_dev	= omap_iommu_attach_dev,
1285 	.detach_dev	= omap_iommu_detach_dev,
1286 	.map		= omap_iommu_map,
1287 	.unmap		= omap_iommu_unmap,
1288 	.iova_to_phys	= omap_iommu_iova_to_phys,
1289 	.add_device	= omap_iommu_add_device,
1290 	.remove_device	= omap_iommu_remove_device,
1291 	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
1292 };
1293 
1294 static int __init omap_iommu_init(void)
1295 {
1296 	struct kmem_cache *p;
1297 	const unsigned long flags = SLAB_HWCACHE_ALIGN;
1298 	size_t align = 1 << 10; /* L2 pagetable alignement */
1299 
1300 	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
1301 			      iopte_cachep_ctor);
1302 	if (!p)
1303 		return -ENOMEM;
1304 	iopte_cachep = p;
1305 
1306 	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
1307 
1308 	return platform_driver_register(&omap_iommu_driver);
1309 }
1310 /* must be ready before omap3isp is probed */
1311 subsys_initcall(omap_iommu_init);
1312 
1313 static void __exit omap_iommu_exit(void)
1314 {
1315 	kmem_cache_destroy(iopte_cachep);
1316 
1317 	platform_driver_unregister(&omap_iommu_driver);
1318 }
1319 module_exit(omap_iommu_exit);
1320 
1321 MODULE_DESCRIPTION("omap iommu: tlb and pagetable primitives");
1322 MODULE_ALIAS("platform:omap-iommu");
1323 MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
1324 MODULE_LICENSE("GPL v2");
1325