1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * omap iommu: tlb and pagetable primitives
4 *
5 * Copyright (C) 2008-2010 Nokia Corporation
6 * Copyright (C) 2013-2017 Texas Instruments Incorporated - https://www.ti.com/
7 *
8 * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
9 *		Paul Mundt and Toshihiro Kobayashi
10 */
11
12#include <linux/dma-mapping.h>
13#include <linux/err.h>
14#include <linux/slab.h>
15#include <linux/interrupt.h>
16#include <linux/ioport.h>
17#include <linux/platform_device.h>
18#include <linux/iommu.h>
19#include <linux/omap-iommu.h>
20#include <linux/mutex.h>
21#include <linux/spinlock.h>
22#include <linux/io.h>
23#include <linux/pm_runtime.h>
24#include <linux/of.h>
25#include <linux/of_iommu.h>
26#include <linux/of_irq.h>
27#include <linux/of_platform.h>
28#include <linux/regmap.h>
29#include <linux/mfd/syscon.h>
30
31#include <linux/platform_data/iommu-omap.h>
32
33#include "omap-iopgtable.h"
34#include "omap-iommu.h"
35
36static const struct iommu_ops omap_iommu_ops;
37
38#define to_iommu(dev)	((struct omap_iommu *)dev_get_drvdata(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#define MMU_LOCK_BASE_SHIFT	10
44#define MMU_LOCK_BASE_MASK	(0x1f << MMU_LOCK_BASE_SHIFT)
45#define MMU_LOCK_BASE(x)	\
46	((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
47
48#define MMU_LOCK_VICT_SHIFT	4
49#define MMU_LOCK_VICT_MASK	(0x1f << MMU_LOCK_VICT_SHIFT)
50#define MMU_LOCK_VICT(x)	\
51	((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
52
53static struct platform_driver omap_iommu_driver;
54static struct kmem_cache *iopte_cachep;
55
56/**
57 * to_omap_domain - Get struct omap_iommu_domain from generic iommu_domain
58 * @dom:	generic iommu domain handle
59 **/
60static struct omap_iommu_domain *to_omap_domain(struct iommu_domain *dom)
61{
62	return container_of(dom, struct omap_iommu_domain, domain);
63}
64
65/**
66 * omap_iommu_save_ctx - Save registers for pm off-mode support
67 * @dev:	client device
68 *
69 * This should be treated as an deprecated API. It is preserved only
70 * to maintain existing functionality for OMAP3 ISP driver.
71 **/
72void omap_iommu_save_ctx(struct device *dev)
73{
74	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
75	struct omap_iommu *obj;
76	u32 *p;
77	int i;
78
79	if (!arch_data)
80		return;
81
82	while (arch_data->iommu_dev) {
83		obj = arch_data->iommu_dev;
84		p = obj->ctx;
85		for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
86			p[i] = iommu_read_reg(obj, i * sizeof(u32));
87			dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
88				p[i]);
89		}
90		arch_data++;
91	}
92}
93EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
94
95/**
96 * omap_iommu_restore_ctx - Restore registers for pm off-mode support
97 * @dev:	client device
98 *
99 * This should be treated as an deprecated API. It is preserved only
100 * to maintain existing functionality for OMAP3 ISP driver.
101 **/
102void omap_iommu_restore_ctx(struct device *dev)
103{
104	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
105	struct omap_iommu *obj;
106	u32 *p;
107	int i;
108
109	if (!arch_data)
110		return;
111
112	while (arch_data->iommu_dev) {
113		obj = arch_data->iommu_dev;
114		p = obj->ctx;
115		for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
116			iommu_write_reg(obj, p[i], i * sizeof(u32));
117			dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
118				p[i]);
119		}
120		arch_data++;
121	}
122}
123EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
124
125static void dra7_cfg_dspsys_mmu(struct omap_iommu *obj, bool enable)
126{
127	u32 val, mask;
128
129	if (!obj->syscfg)
130		return;
131
132	mask = (1 << (obj->id * DSP_SYS_MMU_CONFIG_EN_SHIFT));
133	val = enable ? mask : 0;
134	regmap_update_bits(obj->syscfg, DSP_SYS_MMU_CONFIG, mask, val);
135}
136
137static void __iommu_set_twl(struct omap_iommu *obj, bool on)
138{
139	u32 l = iommu_read_reg(obj, MMU_CNTL);
140
141	if (on)
142		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
143	else
144		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
145
146	l &= ~MMU_CNTL_MASK;
147	if (on)
148		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
149	else
150		l |= (MMU_CNTL_MMU_EN);
151
152	iommu_write_reg(obj, l, MMU_CNTL);
153}
154
155static int omap2_iommu_enable(struct omap_iommu *obj)
156{
157	u32 l, pa;
158
159	if (!obj->iopgd || !IS_ALIGNED((unsigned long)obj->iopgd,  SZ_16K))
160		return -EINVAL;
161
162	pa = virt_to_phys(obj->iopgd);
163	if (!IS_ALIGNED(pa, SZ_16K))
164		return -EINVAL;
165
166	l = iommu_read_reg(obj, MMU_REVISION);
167	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
168		 (l >> 4) & 0xf, l & 0xf);
169
170	iommu_write_reg(obj, pa, MMU_TTB);
171
172	dra7_cfg_dspsys_mmu(obj, true);
173
174	if (obj->has_bus_err_back)
175		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
176
177	__iommu_set_twl(obj, true);
178
179	return 0;
180}
181
182static void omap2_iommu_disable(struct omap_iommu *obj)
183{
184	u32 l = iommu_read_reg(obj, MMU_CNTL);
185
186	l &= ~MMU_CNTL_MASK;
187	iommu_write_reg(obj, l, MMU_CNTL);
188	dra7_cfg_dspsys_mmu(obj, false);
189
190	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
191}
192
193static int iommu_enable(struct omap_iommu *obj)
194{
195	int ret;
196
197	ret = pm_runtime_get_sync(obj->dev);
198	if (ret < 0)
199		pm_runtime_put_noidle(obj->dev);
200
201	return ret < 0 ? ret : 0;
202}
203
204static void iommu_disable(struct omap_iommu *obj)
205{
206	pm_runtime_put_sync(obj->dev);
207}
208
209/*
210 *	TLB operations
211 */
212static u32 iotlb_cr_to_virt(struct cr_regs *cr)
213{
214	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
215	u32 mask = get_cam_va_mask(cr->cam & page_size);
216
217	return cr->cam & mask;
218}
219
220static u32 get_iopte_attr(struct iotlb_entry *e)
221{
222	u32 attr;
223
224	attr = e->mixed << 5;
225	attr |= e->endian;
226	attr |= e->elsz >> 3;
227	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
228			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
229	return attr;
230}
231
232static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
233{
234	u32 status, fault_addr;
235
236	status = iommu_read_reg(obj, MMU_IRQSTATUS);
237	status &= MMU_IRQ_MASK;
238	if (!status) {
239		*da = 0;
240		return 0;
241	}
242
243	fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
244	*da = fault_addr;
245
246	iommu_write_reg(obj, status, MMU_IRQSTATUS);
247
248	return status;
249}
250
251void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
252{
253	u32 val;
254
255	val = iommu_read_reg(obj, MMU_LOCK);
256
257	l->base = MMU_LOCK_BASE(val);
258	l->vict = MMU_LOCK_VICT(val);
259}
260
261void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
262{
263	u32 val;
264
265	val = (l->base << MMU_LOCK_BASE_SHIFT);
266	val |= (l->vict << MMU_LOCK_VICT_SHIFT);
267
268	iommu_write_reg(obj, val, MMU_LOCK);
269}
270
271static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
272{
273	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
274	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
275}
276
277static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
278{
279	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
280	iommu_write_reg(obj, cr->ram, MMU_RAM);
281
282	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
283	iommu_write_reg(obj, 1, MMU_LD_TLB);
284}
285
286/* only used in iotlb iteration for-loop */
287struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
288{
289	struct cr_regs cr;
290	struct iotlb_lock l;
291
292	iotlb_lock_get(obj, &l);
293	l.vict = n;
294	iotlb_lock_set(obj, &l);
295	iotlb_read_cr(obj, &cr);
296
297	return cr;
298}
299
300#ifdef PREFETCH_IOTLB
301static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
302				      struct iotlb_entry *e)
303{
304	struct cr_regs *cr;
305
306	if (!e)
307		return NULL;
308
309	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
310		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
311			e->da);
312		return ERR_PTR(-EINVAL);
313	}
314
315	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
316	if (!cr)
317		return ERR_PTR(-ENOMEM);
318
319	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
320	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
321
322	return cr;
323}
324
325/**
326 * load_iotlb_entry - Set an iommu tlb entry
327 * @obj:	target iommu
328 * @e:		an iommu tlb entry info
329 **/
330static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
331{
332	int err = 0;
333	struct iotlb_lock l;
334	struct cr_regs *cr;
335
336	if (!obj || !obj->nr_tlb_entries || !e)
337		return -EINVAL;
338
339	pm_runtime_get_sync(obj->dev);
340
341	iotlb_lock_get(obj, &l);
342	if (l.base == obj->nr_tlb_entries) {
343		dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
344		err = -EBUSY;
345		goto out;
346	}
347	if (!e->prsvd) {
348		int i;
349		struct cr_regs tmp;
350
351		for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
352			if (!iotlb_cr_valid(&tmp))
353				break;
354
355		if (i == obj->nr_tlb_entries) {
356			dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
357			err = -EBUSY;
358			goto out;
359		}
360
361		iotlb_lock_get(obj, &l);
362	} else {
363		l.vict = l.base;
364		iotlb_lock_set(obj, &l);
365	}
366
367	cr = iotlb_alloc_cr(obj, e);
368	if (IS_ERR(cr)) {
369		pm_runtime_put_sync(obj->dev);
370		return PTR_ERR(cr);
371	}
372
373	iotlb_load_cr(obj, cr);
374	kfree(cr);
375
376	if (e->prsvd)
377		l.base++;
378	/* increment victim for next tlb load */
379	if (++l.vict == obj->nr_tlb_entries)
380		l.vict = l.base;
381	iotlb_lock_set(obj, &l);
382out:
383	pm_runtime_put_sync(obj->dev);
384	return err;
385}
386
387#else /* !PREFETCH_IOTLB */
388
389static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
390{
391	return 0;
392}
393
394#endif /* !PREFETCH_IOTLB */
395
396static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
397{
398	return load_iotlb_entry(obj, e);
399}
400
401/**
402 * flush_iotlb_page - Clear an iommu tlb entry
403 * @obj:	target iommu
404 * @da:		iommu device virtual address
405 *
406 * Clear an iommu tlb entry which includes 'da' address.
407 **/
408static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
409{
410	int i;
411	struct cr_regs cr;
412
413	pm_runtime_get_sync(obj->dev);
414
415	for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
416		u32 start;
417		size_t bytes;
418
419		if (!iotlb_cr_valid(&cr))
420			continue;
421
422		start = iotlb_cr_to_virt(&cr);
423		bytes = iopgsz_to_bytes(cr.cam & 3);
424
425		if ((start <= da) && (da < start + bytes)) {
426			dev_dbg(obj->dev, "%s: %08x<=%08x(%zx)\n",
427				__func__, start, da, bytes);
428			iotlb_load_cr(obj, &cr);
429			iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
430			break;
431		}
432	}
433	pm_runtime_put_sync(obj->dev);
434
435	if (i == obj->nr_tlb_entries)
436		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
437}
438
439/**
440 * flush_iotlb_all - Clear all iommu tlb entries
441 * @obj:	target iommu
442 **/
443static void flush_iotlb_all(struct omap_iommu *obj)
444{
445	struct iotlb_lock l;
446
447	pm_runtime_get_sync(obj->dev);
448
449	l.base = 0;
450	l.vict = 0;
451	iotlb_lock_set(obj, &l);
452
453	iommu_write_reg(obj, 1, MMU_GFLUSH);
454
455	pm_runtime_put_sync(obj->dev);
456}
457
458/*
459 *	H/W pagetable operations
460 */
461static void flush_iopte_range(struct device *dev, dma_addr_t dma,
462			      unsigned long offset, int num_entries)
463{
464	size_t size = num_entries * sizeof(u32);
465
466	dma_sync_single_range_for_device(dev, dma, offset, size, DMA_TO_DEVICE);
467}
468
469static void iopte_free(struct omap_iommu *obj, u32 *iopte, bool dma_valid)
470{
471	dma_addr_t pt_dma;
472
473	/* Note: freed iopte's must be clean ready for re-use */
474	if (iopte) {
475		if (dma_valid) {
476			pt_dma = virt_to_phys(iopte);
477			dma_unmap_single(obj->dev, pt_dma, IOPTE_TABLE_SIZE,
478					 DMA_TO_DEVICE);
479		}
480
481		kmem_cache_free(iopte_cachep, iopte);
482	}
483}
484
485static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd,
486			dma_addr_t *pt_dma, u32 da)
487{
488	u32 *iopte;
489	unsigned long offset = iopgd_index(da) * sizeof(da);
490
491	/* a table has already existed */
492	if (*iopgd)
493		goto pte_ready;
494
495	/*
496	 * do the allocation outside the page table lock
497	 */
498	spin_unlock(&obj->page_table_lock);
499	iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
500	spin_lock(&obj->page_table_lock);
501
502	if (!*iopgd) {
503		if (!iopte)
504			return ERR_PTR(-ENOMEM);
505
506		*pt_dma = dma_map_single(obj->dev, iopte, IOPTE_TABLE_SIZE,
507					 DMA_TO_DEVICE);
508		if (dma_mapping_error(obj->dev, *pt_dma)) {
509			dev_err(obj->dev, "DMA map error for L2 table\n");
510			iopte_free(obj, iopte, false);
511			return ERR_PTR(-ENOMEM);
512		}
513
514		/*
515		 * we rely on dma address and the physical address to be
516		 * the same for mapping the L2 table
517		 */
518		if (WARN_ON(*pt_dma != virt_to_phys(iopte))) {
519			dev_err(obj->dev, "DMA translation error for L2 table\n");
520			dma_unmap_single(obj->dev, *pt_dma, IOPTE_TABLE_SIZE,
521					 DMA_TO_DEVICE);
522			iopte_free(obj, iopte, false);
523			return ERR_PTR(-ENOMEM);
524		}
525
526		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
527
528		flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
529		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
530	} else {
531		/* We raced, free the reduniovant table */
532		iopte_free(obj, iopte, false);
533	}
534
535pte_ready:
536	iopte = iopte_offset(iopgd, da);
537	*pt_dma = iopgd_page_paddr(iopgd);
538	dev_vdbg(obj->dev,
539		 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
540		 __func__, da, iopgd, *iopgd, iopte, *iopte);
541
542	return iopte;
543}
544
545static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
546{
547	u32 *iopgd = iopgd_offset(obj, da);
548	unsigned long offset = iopgd_index(da) * sizeof(da);
549
550	if ((da | pa) & ~IOSECTION_MASK) {
551		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
552			__func__, da, pa, IOSECTION_SIZE);
553		return -EINVAL;
554	}
555
556	*iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
557	flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
558	return 0;
559}
560
561static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
562{
563	u32 *iopgd = iopgd_offset(obj, da);
564	unsigned long offset = iopgd_index(da) * sizeof(da);
565	int i;
566
567	if ((da | pa) & ~IOSUPER_MASK) {
568		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
569			__func__, da, pa, IOSUPER_SIZE);
570		return -EINVAL;
571	}
572
573	for (i = 0; i < 16; i++)
574		*(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
575	flush_iopte_range(obj->dev, obj->pd_dma, offset, 16);
576	return 0;
577}
578
579static int iopte_alloc_page(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
580{
581	u32 *iopgd = iopgd_offset(obj, da);
582	dma_addr_t pt_dma;
583	u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
584	unsigned long offset = iopte_index(da) * sizeof(da);
585
586	if (IS_ERR(iopte))
587		return PTR_ERR(iopte);
588
589	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
590	flush_iopte_range(obj->dev, pt_dma, offset, 1);
591
592	dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
593		 __func__, da, pa, iopte, *iopte);
594
595	return 0;
596}
597
598static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
599{
600	u32 *iopgd = iopgd_offset(obj, da);
601	dma_addr_t pt_dma;
602	u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
603	unsigned long offset = iopte_index(da) * sizeof(da);
604	int i;
605
606	if ((da | pa) & ~IOLARGE_MASK) {
607		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
608			__func__, da, pa, IOLARGE_SIZE);
609		return -EINVAL;
610	}
611
612	if (IS_ERR(iopte))
613		return PTR_ERR(iopte);
614
615	for (i = 0; i < 16; i++)
616		*(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
617	flush_iopte_range(obj->dev, pt_dma, offset, 16);
618	return 0;
619}
620
621static int
622iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
623{
624	int (*fn)(struct omap_iommu *, u32, u32, u32);
625	u32 prot;
626	int err;
627
628	if (!obj || !e)
629		return -EINVAL;
630
631	switch (e->pgsz) {
632	case MMU_CAM_PGSZ_16M:
633		fn = iopgd_alloc_super;
634		break;
635	case MMU_CAM_PGSZ_1M:
636		fn = iopgd_alloc_section;
637		break;
638	case MMU_CAM_PGSZ_64K:
639		fn = iopte_alloc_large;
640		break;
641	case MMU_CAM_PGSZ_4K:
642		fn = iopte_alloc_page;
643		break;
644	default:
645		fn = NULL;
646		break;
647	}
648
649	if (WARN_ON(!fn))
650		return -EINVAL;
651
652	prot = get_iopte_attr(e);
653
654	spin_lock(&obj->page_table_lock);
655	err = fn(obj, e->da, e->pa, prot);
656	spin_unlock(&obj->page_table_lock);
657
658	return err;
659}
660
661/**
662 * omap_iopgtable_store_entry - Make an iommu pte entry
663 * @obj:	target iommu
664 * @e:		an iommu tlb entry info
665 **/
666static int
667omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
668{
669	int err;
670
671	flush_iotlb_page(obj, e->da);
672	err = iopgtable_store_entry_core(obj, e);
673	if (!err)
674		prefetch_iotlb_entry(obj, e);
675	return err;
676}
677
678/**
679 * iopgtable_lookup_entry - Lookup an iommu pte entry
680 * @obj:	target iommu
681 * @da:		iommu device virtual address
682 * @ppgd:	iommu pgd entry pointer to be returned
683 * @ppte:	iommu pte entry pointer to be returned
684 **/
685static void
686iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
687{
688	u32 *iopgd, *iopte = NULL;
689
690	iopgd = iopgd_offset(obj, da);
691	if (!*iopgd)
692		goto out;
693
694	if (iopgd_is_table(*iopgd))
695		iopte = iopte_offset(iopgd, da);
696out:
697	*ppgd = iopgd;
698	*ppte = iopte;
699}
700
701static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
702{
703	size_t bytes;
704	u32 *iopgd = iopgd_offset(obj, da);
705	int nent = 1;
706	dma_addr_t pt_dma;
707	unsigned long pd_offset = iopgd_index(da) * sizeof(da);
708	unsigned long pt_offset = iopte_index(da) * sizeof(da);
709
710	if (!*iopgd)
711		return 0;
712
713	if (iopgd_is_table(*iopgd)) {
714		int i;
715		u32 *iopte = iopte_offset(iopgd, da);
716
717		bytes = IOPTE_SIZE;
718		if (*iopte & IOPTE_LARGE) {
719			nent *= 16;
720			/* rewind to the 1st entry */
721			iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
722		}
723		bytes *= nent;
724		memset(iopte, 0, nent * sizeof(*iopte));
725		pt_dma = iopgd_page_paddr(iopgd);
726		flush_iopte_range(obj->dev, pt_dma, pt_offset, nent);
727
728		/*
729		 * do table walk to check if this table is necessary or not
730		 */
731		iopte = iopte_offset(iopgd, 0);
732		for (i = 0; i < PTRS_PER_IOPTE; i++)
733			if (iopte[i])
734				goto out;
735
736		iopte_free(obj, iopte, true);
737		nent = 1; /* for the next L1 entry */
738	} else {
739		bytes = IOPGD_SIZE;
740		if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
741			nent *= 16;
742			/* rewind to the 1st entry */
743			iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
744		}
745		bytes *= nent;
746	}
747	memset(iopgd, 0, nent * sizeof(*iopgd));
748	flush_iopte_range(obj->dev, obj->pd_dma, pd_offset, nent);
749out:
750	return bytes;
751}
752
753/**
754 * iopgtable_clear_entry - Remove an iommu pte entry
755 * @obj:	target iommu
756 * @da:		iommu device virtual address
757 **/
758static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
759{
760	size_t bytes;
761
762	spin_lock(&obj->page_table_lock);
763
764	bytes = iopgtable_clear_entry_core(obj, da);
765	flush_iotlb_page(obj, da);
766
767	spin_unlock(&obj->page_table_lock);
768
769	return bytes;
770}
771
772static void iopgtable_clear_entry_all(struct omap_iommu *obj)
773{
774	unsigned long offset;
775	int i;
776
777	spin_lock(&obj->page_table_lock);
778
779	for (i = 0; i < PTRS_PER_IOPGD; i++) {
780		u32 da;
781		u32 *iopgd;
782
783		da = i << IOPGD_SHIFT;
784		iopgd = iopgd_offset(obj, da);
785		offset = iopgd_index(da) * sizeof(da);
786
787		if (!*iopgd)
788			continue;
789
790		if (iopgd_is_table(*iopgd))
791			iopte_free(obj, iopte_offset(iopgd, 0), true);
792
793		*iopgd = 0;
794		flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
795	}
796
797	flush_iotlb_all(obj);
798
799	spin_unlock(&obj->page_table_lock);
800}
801
802/*
803 *	Device IOMMU generic operations
804 */
805static irqreturn_t iommu_fault_handler(int irq, void *data)
806{
807	u32 da, errs;
808	u32 *iopgd, *iopte;
809	struct omap_iommu *obj = data;
810	struct iommu_domain *domain = obj->domain;
811	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
812
813	if (!omap_domain->dev)
814		return IRQ_NONE;
815
816	errs = iommu_report_fault(obj, &da);
817	if (errs == 0)
818		return IRQ_HANDLED;
819
820	/* Fault callback or TLB/PTE Dynamic loading */
821	if (!report_iommu_fault(domain, obj->dev, da, 0))
822		return IRQ_HANDLED;
823
824	iommu_write_reg(obj, 0, MMU_IRQENABLE);
825
826	iopgd = iopgd_offset(obj, da);
827
828	if (!iopgd_is_table(*iopgd)) {
829		dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
830			obj->name, errs, da, iopgd, *iopgd);
831		return IRQ_NONE;
832	}
833
834	iopte = iopte_offset(iopgd, da);
835
836	dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
837		obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
838
839	return IRQ_NONE;
840}
841
842/**
843 * omap_iommu_attach() - attach iommu device to an iommu domain
844 * @obj:	target omap iommu device
845 * @iopgd:	page table
846 **/
847static int omap_iommu_attach(struct omap_iommu *obj, u32 *iopgd)
848{
849	int err;
850
851	spin_lock(&obj->iommu_lock);
852
853	obj->pd_dma = dma_map_single(obj->dev, iopgd, IOPGD_TABLE_SIZE,
854				     DMA_TO_DEVICE);
855	if (dma_mapping_error(obj->dev, obj->pd_dma)) {
856		dev_err(obj->dev, "DMA map error for L1 table\n");
857		err = -ENOMEM;
858		goto out_err;
859	}
860
861	obj->iopgd = iopgd;
862	err = iommu_enable(obj);
863	if (err)
864		goto out_err;
865	flush_iotlb_all(obj);
866
867	spin_unlock(&obj->iommu_lock);
868
869	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
870
871	return 0;
872
873out_err:
874	spin_unlock(&obj->iommu_lock);
875
876	return err;
877}
878
879/**
880 * omap_iommu_detach - release iommu device
881 * @obj:	target iommu
882 **/
883static void omap_iommu_detach(struct omap_iommu *obj)
884{
885	if (!obj || IS_ERR(obj))
886		return;
887
888	spin_lock(&obj->iommu_lock);
889
890	dma_unmap_single(obj->dev, obj->pd_dma, IOPGD_TABLE_SIZE,
891			 DMA_TO_DEVICE);
892	obj->pd_dma = 0;
893	obj->iopgd = NULL;
894	iommu_disable(obj);
895
896	spin_unlock(&obj->iommu_lock);
897
898	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
899}
900
901static void omap_iommu_save_tlb_entries(struct omap_iommu *obj)
902{
903	struct iotlb_lock lock;
904	struct cr_regs cr;
905	struct cr_regs *tmp;
906	int i;
907
908	/* check if there are any locked tlbs to save */
909	iotlb_lock_get(obj, &lock);
910	obj->num_cr_ctx = lock.base;
911	if (!obj->num_cr_ctx)
912		return;
913
914	tmp = obj->cr_ctx;
915	for_each_iotlb_cr(obj, obj->num_cr_ctx, i, cr)
916		* tmp++ = cr;
917}
918
919static void omap_iommu_restore_tlb_entries(struct omap_iommu *obj)
920{
921	struct iotlb_lock l;
922	struct cr_regs *tmp;
923	int i;
924
925	/* no locked tlbs to restore */
926	if (!obj->num_cr_ctx)
927		return;
928
929	l.base = 0;
930	tmp = obj->cr_ctx;
931	for (i = 0; i < obj->num_cr_ctx; i++, tmp++) {
932		l.vict = i;
933		iotlb_lock_set(obj, &l);
934		iotlb_load_cr(obj, tmp);
935	}
936	l.base = obj->num_cr_ctx;
937	l.vict = i;
938	iotlb_lock_set(obj, &l);
939}
940
941/**
942 * omap_iommu_domain_deactivate - deactivate attached iommu devices
943 * @domain: iommu domain attached to the target iommu device
944 *
945 * This API allows the client devices of IOMMU devices to suspend
946 * the IOMMUs they control at runtime, after they are idled and
947 * suspended all activity. System Suspend will leverage the PM
948 * driver late callbacks.
949 **/
950int omap_iommu_domain_deactivate(struct iommu_domain *domain)
951{
952	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
953	struct omap_iommu_device *iommu;
954	struct omap_iommu *oiommu;
955	int i;
956
957	if (!omap_domain->dev)
958		return 0;
959
960	iommu = omap_domain->iommus;
961	iommu += (omap_domain->num_iommus - 1);
962	for (i = 0; i < omap_domain->num_iommus; i++, iommu--) {
963		oiommu = iommu->iommu_dev;
964		pm_runtime_put_sync(oiommu->dev);
965	}
966
967	return 0;
968}
969EXPORT_SYMBOL_GPL(omap_iommu_domain_deactivate);
970
971/**
972 * omap_iommu_domain_activate - activate attached iommu devices
973 * @domain: iommu domain attached to the target iommu device
974 *
975 * This API allows the client devices of IOMMU devices to resume the
976 * IOMMUs they control at runtime, before they can resume operations.
977 * System Resume will leverage the PM driver late callbacks.
978 **/
979int omap_iommu_domain_activate(struct iommu_domain *domain)
980{
981	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
982	struct omap_iommu_device *iommu;
983	struct omap_iommu *oiommu;
984	int i;
985
986	if (!omap_domain->dev)
987		return 0;
988
989	iommu = omap_domain->iommus;
990	for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
991		oiommu = iommu->iommu_dev;
992		pm_runtime_get_sync(oiommu->dev);
993	}
994
995	return 0;
996}
997EXPORT_SYMBOL_GPL(omap_iommu_domain_activate);
998
999/**
1000 * omap_iommu_runtime_suspend - disable an iommu device
1001 * @dev:	iommu device
1002 *
1003 * This function performs all that is necessary to disable an
1004 * IOMMU device, either during final detachment from a client
1005 * device, or during system/runtime suspend of the device. This
1006 * includes programming all the appropriate IOMMU registers, and
1007 * managing the associated omap_hwmod's state and the device's
1008 * reset line. This function also saves the context of any
1009 * locked TLBs if suspending.
1010 **/
1011static __maybe_unused int omap_iommu_runtime_suspend(struct device *dev)
1012{
1013	struct platform_device *pdev = to_platform_device(dev);
1014	struct iommu_platform_data *pdata = dev_get_platdata(dev);
1015	struct omap_iommu *obj = to_iommu(dev);
1016	int ret;
1017
1018	/* save the TLBs only during suspend, and not for power down */
1019	if (obj->domain && obj->iopgd)
1020		omap_iommu_save_tlb_entries(obj);
1021
1022	omap2_iommu_disable(obj);
1023
1024	if (pdata && pdata->device_idle)
1025		pdata->device_idle(pdev);
1026
1027	if (pdata && pdata->assert_reset)
1028		pdata->assert_reset(pdev, pdata->reset_name);
1029
1030	if (pdata && pdata->set_pwrdm_constraint) {
1031		ret = pdata->set_pwrdm_constraint(pdev, false, &obj->pwrst);
1032		if (ret) {
1033			dev_warn(obj->dev, "pwrdm_constraint failed to be reset, status = %d\n",
1034				 ret);
1035		}
1036	}
1037
1038	return 0;
1039}
1040
1041/**
1042 * omap_iommu_runtime_resume - enable an iommu device
1043 * @dev:	iommu device
1044 *
1045 * This function performs all that is necessary to enable an
1046 * IOMMU device, either during initial attachment to a client
1047 * device, or during system/runtime resume of the device. This
1048 * includes programming all the appropriate IOMMU registers, and
1049 * managing the associated omap_hwmod's state and the device's
1050 * reset line. The function also restores any locked TLBs if
1051 * resuming after a suspend.
1052 **/
1053static __maybe_unused int omap_iommu_runtime_resume(struct device *dev)
1054{
1055	struct platform_device *pdev = to_platform_device(dev);
1056	struct iommu_platform_data *pdata = dev_get_platdata(dev);
1057	struct omap_iommu *obj = to_iommu(dev);
1058	int ret = 0;
1059
1060	if (pdata && pdata->set_pwrdm_constraint) {
1061		ret = pdata->set_pwrdm_constraint(pdev, true, &obj->pwrst);
1062		if (ret) {
1063			dev_warn(obj->dev, "pwrdm_constraint failed to be set, status = %d\n",
1064				 ret);
1065		}
1066	}
1067
1068	if (pdata && pdata->deassert_reset) {
1069		ret = pdata->deassert_reset(pdev, pdata->reset_name);
1070		if (ret) {
1071			dev_err(dev, "deassert_reset failed: %d\n", ret);
1072			return ret;
1073		}
1074	}
1075
1076	if (pdata && pdata->device_enable)
1077		pdata->device_enable(pdev);
1078
1079	/* restore the TLBs only during resume, and not for power up */
1080	if (obj->domain)
1081		omap_iommu_restore_tlb_entries(obj);
1082
1083	ret = omap2_iommu_enable(obj);
1084
1085	return ret;
1086}
1087
1088/**
1089 * omap_iommu_suspend_prepare - prepare() dev_pm_ops implementation
1090 * @dev:	iommu device
1091 *
1092 * This function performs the necessary checks to determine if the IOMMU
1093 * device needs suspending or not. The function checks if the runtime_pm
1094 * status of the device is suspended, and returns 1 in that case. This
1095 * results in the PM core to skip invoking any of the Sleep PM callbacks
1096 * (suspend, suspend_late, resume, resume_early etc).
1097 */
1098static int omap_iommu_prepare(struct device *dev)
1099{
1100	if (pm_runtime_status_suspended(dev))
1101		return 1;
1102	return 0;
1103}
1104
1105static bool omap_iommu_can_register(struct platform_device *pdev)
1106{
1107	struct device_node *np = pdev->dev.of_node;
1108
1109	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
1110		return true;
1111
1112	/*
1113	 * restrict IOMMU core registration only for processor-port MDMA MMUs
1114	 * on DRA7 DSPs
1115	 */
1116	if ((!strcmp(dev_name(&pdev->dev), "40d01000.mmu")) ||
1117	    (!strcmp(dev_name(&pdev->dev), "41501000.mmu")))
1118		return true;
1119
1120	return false;
1121}
1122
1123static int omap_iommu_dra7_get_dsp_system_cfg(struct platform_device *pdev,
1124					      struct omap_iommu *obj)
1125{
1126	struct device_node *np = pdev->dev.of_node;
1127	int ret;
1128
1129	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
1130		return 0;
1131
1132	if (!of_property_read_bool(np, "ti,syscon-mmuconfig")) {
1133		dev_err(&pdev->dev, "ti,syscon-mmuconfig property is missing\n");
1134		return -EINVAL;
1135	}
1136
1137	obj->syscfg =
1138		syscon_regmap_lookup_by_phandle(np, "ti,syscon-mmuconfig");
1139	if (IS_ERR(obj->syscfg)) {
1140		/* can fail with -EPROBE_DEFER */
1141		ret = PTR_ERR(obj->syscfg);
1142		return ret;
1143	}
1144
1145	if (of_property_read_u32_index(np, "ti,syscon-mmuconfig", 1,
1146				       &obj->id)) {
1147		dev_err(&pdev->dev, "couldn't get the IOMMU instance id within subsystem\n");
1148		return -EINVAL;
1149	}
1150
1151	if (obj->id != 0 && obj->id != 1) {
1152		dev_err(&pdev->dev, "invalid IOMMU instance id\n");
1153		return -EINVAL;
1154	}
1155
1156	return 0;
1157}
1158
1159/*
1160 *	OMAP Device MMU(IOMMU) detection
1161 */
1162static int omap_iommu_probe(struct platform_device *pdev)
1163{
1164	int err = -ENODEV;
1165	int irq;
1166	struct omap_iommu *obj;
1167	struct resource *res;
1168	struct device_node *of = pdev->dev.of_node;
1169
1170	if (!of) {
1171		pr_err("%s: only DT-based devices are supported\n", __func__);
1172		return -ENODEV;
1173	}
1174
1175	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
1176	if (!obj)
1177		return -ENOMEM;
1178
1179	/*
1180	 * self-manage the ordering dependencies between omap_device_enable/idle
1181	 * and omap_device_assert/deassert_hardreset API
1182	 */
1183	if (pdev->dev.pm_domain) {
1184		dev_dbg(&pdev->dev, "device pm_domain is being reset\n");
1185		pdev->dev.pm_domain = NULL;
1186	}
1187
1188	obj->name = dev_name(&pdev->dev);
1189	obj->nr_tlb_entries = 32;
1190	err = of_property_read_u32(of, "ti,#tlb-entries", &obj->nr_tlb_entries);
1191	if (err && err != -EINVAL)
1192		return err;
1193	if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
1194		return -EINVAL;
1195	if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
1196		obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
1197
1198	obj->dev = &pdev->dev;
1199	obj->ctx = (void *)obj + sizeof(*obj);
1200	obj->cr_ctx = devm_kzalloc(&pdev->dev,
1201				   sizeof(*obj->cr_ctx) * obj->nr_tlb_entries,
1202				   GFP_KERNEL);
1203	if (!obj->cr_ctx)
1204		return -ENOMEM;
1205
1206	spin_lock_init(&obj->iommu_lock);
1207	spin_lock_init(&obj->page_table_lock);
1208
1209	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1210	obj->regbase = devm_ioremap_resource(obj->dev, res);
1211	if (IS_ERR(obj->regbase))
1212		return PTR_ERR(obj->regbase);
1213
1214	err = omap_iommu_dra7_get_dsp_system_cfg(pdev, obj);
1215	if (err)
1216		return err;
1217
1218	irq = platform_get_irq(pdev, 0);
1219	if (irq < 0)
1220		return -ENODEV;
1221
1222	err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
1223			       dev_name(obj->dev), obj);
1224	if (err < 0)
1225		return err;
1226	platform_set_drvdata(pdev, obj);
1227
1228	if (omap_iommu_can_register(pdev)) {
1229		obj->group = iommu_group_alloc();
1230		if (IS_ERR(obj->group))
1231			return PTR_ERR(obj->group);
1232
1233		err = iommu_device_sysfs_add(&obj->iommu, obj->dev, NULL,
1234					     obj->name);
1235		if (err)
1236			goto out_group;
1237
1238		iommu_device_set_ops(&obj->iommu, &omap_iommu_ops);
1239		iommu_device_set_fwnode(&obj->iommu, &of->fwnode);
1240
1241		err = iommu_device_register(&obj->iommu);
1242		if (err)
1243			goto out_sysfs;
1244	}
1245
1246	pm_runtime_enable(obj->dev);
1247
1248	omap_iommu_debugfs_add(obj);
1249
1250	dev_info(&pdev->dev, "%s registered\n", obj->name);
1251
1252	/* Re-probe bus to probe device attached to this IOMMU */
1253	bus_iommu_probe(&platform_bus_type);
1254
1255	return 0;
1256
1257out_sysfs:
1258	iommu_device_sysfs_remove(&obj->iommu);
1259out_group:
1260	iommu_group_put(obj->group);
1261	return err;
1262}
1263
1264static int omap_iommu_remove(struct platform_device *pdev)
1265{
1266	struct omap_iommu *obj = platform_get_drvdata(pdev);
1267
1268	if (obj->group) {
1269		iommu_group_put(obj->group);
1270		obj->group = NULL;
1271
1272		iommu_device_sysfs_remove(&obj->iommu);
1273		iommu_device_unregister(&obj->iommu);
1274	}
1275
1276	omap_iommu_debugfs_remove(obj);
1277
1278	pm_runtime_disable(obj->dev);
1279
1280	dev_info(&pdev->dev, "%s removed\n", obj->name);
1281	return 0;
1282}
1283
1284static const struct dev_pm_ops omap_iommu_pm_ops = {
1285	.prepare = omap_iommu_prepare,
1286	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1287				     pm_runtime_force_resume)
1288	SET_RUNTIME_PM_OPS(omap_iommu_runtime_suspend,
1289			   omap_iommu_runtime_resume, NULL)
1290};
1291
1292static const struct of_device_id omap_iommu_of_match[] = {
1293	{ .compatible = "ti,omap2-iommu" },
1294	{ .compatible = "ti,omap4-iommu" },
1295	{ .compatible = "ti,dra7-iommu"	},
1296	{ .compatible = "ti,dra7-dsp-iommu" },
1297	{},
1298};
1299
1300static struct platform_driver omap_iommu_driver = {
1301	.probe	= omap_iommu_probe,
1302	.remove	= omap_iommu_remove,
1303	.driver	= {
1304		.name	= "omap-iommu",
1305		.pm	= &omap_iommu_pm_ops,
1306		.of_match_table = of_match_ptr(omap_iommu_of_match),
1307	},
1308};
1309
1310static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
1311{
1312	memset(e, 0, sizeof(*e));
1313
1314	e->da		= da;
1315	e->pa		= pa;
1316	e->valid	= MMU_CAM_V;
1317	e->pgsz		= pgsz;
1318	e->endian	= MMU_RAM_ENDIAN_LITTLE;
1319	e->elsz		= MMU_RAM_ELSZ_8;
1320	e->mixed	= 0;
1321
1322	return iopgsz_to_bytes(e->pgsz);
1323}
1324
1325static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
1326			  phys_addr_t pa, size_t bytes, int prot, gfp_t gfp)
1327{
1328	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1329	struct device *dev = omap_domain->dev;
1330	struct omap_iommu_device *iommu;
1331	struct omap_iommu *oiommu;
1332	struct iotlb_entry e;
1333	int omap_pgsz;
1334	u32 ret = -EINVAL;
1335	int i;
1336
1337	omap_pgsz = bytes_to_iopgsz(bytes);
1338	if (omap_pgsz < 0) {
1339		dev_err(dev, "invalid size to map: %zu\n", bytes);
1340		return -EINVAL;
1341	}
1342
1343	dev_dbg(dev, "mapping da 0x%lx to pa %pa size 0x%zx\n", da, &pa, bytes);
1344
1345	iotlb_init_entry(&e, da, pa, omap_pgsz);
1346
1347	iommu = omap_domain->iommus;
1348	for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
1349		oiommu = iommu->iommu_dev;
1350		ret = omap_iopgtable_store_entry(oiommu, &e);
1351		if (ret) {
1352			dev_err(dev, "omap_iopgtable_store_entry failed: %d\n",
1353				ret);
1354			break;
1355		}
1356	}
1357
1358	if (ret) {
1359		while (i--) {
1360			iommu--;
1361			oiommu = iommu->iommu_dev;
1362			iopgtable_clear_entry(oiommu, da);
1363		}
1364	}
1365
1366	return ret;
1367}
1368
1369static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
1370			       size_t size, struct iommu_iotlb_gather *gather)
1371{
1372	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1373	struct device *dev = omap_domain->dev;
1374	struct omap_iommu_device *iommu;
1375	struct omap_iommu *oiommu;
1376	bool error = false;
1377	size_t bytes = 0;
1378	int i;
1379
1380	dev_dbg(dev, "unmapping da 0x%lx size %zu\n", da, size);
1381
1382	iommu = omap_domain->iommus;
1383	for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
1384		oiommu = iommu->iommu_dev;
1385		bytes = iopgtable_clear_entry(oiommu, da);
1386		if (!bytes)
1387			error = true;
1388	}
1389
1390	/*
1391	 * simplify return - we are only checking if any of the iommus
1392	 * reported an error, but not if all of them are unmapping the
1393	 * same number of entries. This should not occur due to the
1394	 * mirror programming.
1395	 */
1396	return error ? 0 : bytes;
1397}
1398
1399static int omap_iommu_count(struct device *dev)
1400{
1401	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1402	int count = 0;
1403
1404	while (arch_data->iommu_dev) {
1405		count++;
1406		arch_data++;
1407	}
1408
1409	return count;
1410}
1411
1412/* caller should call cleanup if this function fails */
1413static int omap_iommu_attach_init(struct device *dev,
1414				  struct omap_iommu_domain *odomain)
1415{
1416	struct omap_iommu_device *iommu;
1417	int i;
1418
1419	odomain->num_iommus = omap_iommu_count(dev);
1420	if (!odomain->num_iommus)
1421		return -EINVAL;
1422
1423	odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu),
1424				  GFP_ATOMIC);
1425	if (!odomain->iommus)
1426		return -ENOMEM;
1427
1428	iommu = odomain->iommus;
1429	for (i = 0; i < odomain->num_iommus; i++, iommu++) {
1430		iommu->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_ATOMIC);
1431		if (!iommu->pgtable)
1432			return -ENOMEM;
1433
1434		/*
1435		 * should never fail, but please keep this around to ensure
1436		 * we keep the hardware happy
1437		 */
1438		if (WARN_ON(!IS_ALIGNED((long)iommu->pgtable,
1439					IOPGD_TABLE_SIZE)))
1440			return -EINVAL;
1441	}
1442
1443	return 0;
1444}
1445
1446static void omap_iommu_detach_fini(struct omap_iommu_domain *odomain)
1447{
1448	int i;
1449	struct omap_iommu_device *iommu = odomain->iommus;
1450
1451	for (i = 0; iommu && i < odomain->num_iommus; i++, iommu++)
1452		kfree(iommu->pgtable);
1453
1454	kfree(odomain->iommus);
1455	odomain->num_iommus = 0;
1456	odomain->iommus = NULL;
1457}
1458
1459static int
1460omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
1461{
1462	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1463	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1464	struct omap_iommu_device *iommu;
1465	struct omap_iommu *oiommu;
1466	int ret = 0;
1467	int i;
1468
1469	if (!arch_data || !arch_data->iommu_dev) {
1470		dev_err(dev, "device doesn't have an associated iommu\n");
1471		return -EINVAL;
1472	}
1473
1474	spin_lock(&omap_domain->lock);
1475
1476	/* only a single client device can be attached to a domain */
1477	if (omap_domain->dev) {
1478		dev_err(dev, "iommu domain is already attached\n");
1479		ret = -EBUSY;
1480		goto out;
1481	}
1482
1483	ret = omap_iommu_attach_init(dev, omap_domain);
1484	if (ret) {
1485		dev_err(dev, "failed to allocate required iommu data %d\n",
1486			ret);
1487		goto init_fail;
1488	}
1489
1490	iommu = omap_domain->iommus;
1491	for (i = 0; i < omap_domain->num_iommus; i++, iommu++, arch_data++) {
1492		/* configure and enable the omap iommu */
1493		oiommu = arch_data->iommu_dev;
1494		ret = omap_iommu_attach(oiommu, iommu->pgtable);
1495		if (ret) {
1496			dev_err(dev, "can't get omap iommu: %d\n", ret);
1497			goto attach_fail;
1498		}
1499
1500		oiommu->domain = domain;
1501		iommu->iommu_dev = oiommu;
1502	}
1503
1504	omap_domain->dev = dev;
1505
1506	goto out;
1507
1508attach_fail:
1509	while (i--) {
1510		iommu--;
1511		arch_data--;
1512		oiommu = iommu->iommu_dev;
1513		omap_iommu_detach(oiommu);
1514		iommu->iommu_dev = NULL;
1515		oiommu->domain = NULL;
1516	}
1517init_fail:
1518	omap_iommu_detach_fini(omap_domain);
1519out:
1520	spin_unlock(&omap_domain->lock);
1521	return ret;
1522}
1523
1524static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
1525				   struct device *dev)
1526{
1527	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1528	struct omap_iommu_device *iommu = omap_domain->iommus;
1529	struct omap_iommu *oiommu;
1530	int i;
1531
1532	if (!omap_domain->dev) {
1533		dev_err(dev, "domain has no attached device\n");
1534		return;
1535	}
1536
1537	/* only a single device is supported per domain for now */
1538	if (omap_domain->dev != dev) {
1539		dev_err(dev, "invalid attached device\n");
1540		return;
1541	}
1542
1543	/*
1544	 * cleanup in the reverse order of attachment - this addresses
1545	 * any h/w dependencies between multiple instances, if any
1546	 */
1547	iommu += (omap_domain->num_iommus - 1);
1548	arch_data += (omap_domain->num_iommus - 1);
1549	for (i = 0; i < omap_domain->num_iommus; i++, iommu--, arch_data--) {
1550		oiommu = iommu->iommu_dev;
1551		iopgtable_clear_entry_all(oiommu);
1552
1553		omap_iommu_detach(oiommu);
1554		iommu->iommu_dev = NULL;
1555		oiommu->domain = NULL;
1556	}
1557
1558	omap_iommu_detach_fini(omap_domain);
1559
1560	omap_domain->dev = NULL;
1561}
1562
1563static void omap_iommu_detach_dev(struct iommu_domain *domain,
1564				  struct device *dev)
1565{
1566	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1567
1568	spin_lock(&omap_domain->lock);
1569	_omap_iommu_detach_dev(omap_domain, dev);
1570	spin_unlock(&omap_domain->lock);
1571}
1572
1573static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
1574{
1575	struct omap_iommu_domain *omap_domain;
1576
1577	if (type != IOMMU_DOMAIN_UNMANAGED)
1578		return NULL;
1579
1580	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
1581	if (!omap_domain)
1582		return NULL;
1583
1584	spin_lock_init(&omap_domain->lock);
1585
1586	omap_domain->domain.geometry.aperture_start = 0;
1587	omap_domain->domain.geometry.aperture_end   = (1ULL << 32) - 1;
1588	omap_domain->domain.geometry.force_aperture = true;
1589
1590	return &omap_domain->domain;
1591}
1592
1593static void omap_iommu_domain_free(struct iommu_domain *domain)
1594{
1595	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1596
1597	/*
1598	 * An iommu device is still attached
1599	 * (currently, only one device can be attached) ?
1600	 */
1601	if (omap_domain->dev)
1602		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
1603
1604	kfree(omap_domain);
1605}
1606
1607static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
1608					   dma_addr_t da)
1609{
1610	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1611	struct omap_iommu_device *iommu = omap_domain->iommus;
1612	struct omap_iommu *oiommu = iommu->iommu_dev;
1613	struct device *dev = oiommu->dev;
1614	u32 *pgd, *pte;
1615	phys_addr_t ret = 0;
1616
1617	/*
1618	 * all the iommus within the domain will have identical programming,
1619	 * so perform the lookup using just the first iommu
1620	 */
1621	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
1622
1623	if (pte) {
1624		if (iopte_is_small(*pte))
1625			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
1626		else if (iopte_is_large(*pte))
1627			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
1628		else
1629			dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
1630				(unsigned long long)da);
1631	} else {
1632		if (iopgd_is_section(*pgd))
1633			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
1634		else if (iopgd_is_super(*pgd))
1635			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
1636		else
1637			dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
1638				(unsigned long long)da);
1639	}
1640
1641	return ret;
1642}
1643
1644static struct iommu_device *omap_iommu_probe_device(struct device *dev)
1645{
1646	struct omap_iommu_arch_data *arch_data, *tmp;
1647	struct platform_device *pdev;
1648	struct omap_iommu *oiommu;
1649	struct device_node *np;
1650	int num_iommus, i;
1651
1652	/*
1653	 * Allocate the per-device iommu structure for DT-based devices.
1654	 *
1655	 * TODO: Simplify this when removing non-DT support completely from the
1656	 * IOMMU users.
1657	 */
1658	if (!dev->of_node)
1659		return ERR_PTR(-ENODEV);
1660
1661	/*
1662	 * retrieve the count of IOMMU nodes using phandle size as element size
1663	 * since #iommu-cells = 0 for OMAP
1664	 */
1665	num_iommus = of_property_count_elems_of_size(dev->of_node, "iommus",
1666						     sizeof(phandle));
1667	if (num_iommus < 0)
1668		return ERR_PTR(-ENODEV);
1669
1670	arch_data = kcalloc(num_iommus + 1, sizeof(*arch_data), GFP_KERNEL);
1671	if (!arch_data)
1672		return ERR_PTR(-ENOMEM);
1673
1674	for (i = 0, tmp = arch_data; i < num_iommus; i++, tmp++) {
1675		np = of_parse_phandle(dev->of_node, "iommus", i);
1676		if (!np) {
1677			kfree(arch_data);
1678			return ERR_PTR(-EINVAL);
1679		}
1680
1681		pdev = of_find_device_by_node(np);
1682		if (!pdev) {
1683			of_node_put(np);
1684			kfree(arch_data);
1685			return ERR_PTR(-ENODEV);
1686		}
1687
1688		oiommu = platform_get_drvdata(pdev);
1689		if (!oiommu) {
1690			of_node_put(np);
1691			kfree(arch_data);
1692			return ERR_PTR(-EINVAL);
1693		}
1694
1695		tmp->iommu_dev = oiommu;
1696		tmp->dev = &pdev->dev;
1697
1698		of_node_put(np);
1699	}
1700
1701	dev_iommu_priv_set(dev, arch_data);
1702
1703	/*
1704	 * use the first IOMMU alone for the sysfs device linking.
1705	 * TODO: Evaluate if a single iommu_group needs to be
1706	 * maintained for both IOMMUs
1707	 */
1708	oiommu = arch_data->iommu_dev;
1709
1710	return &oiommu->iommu;
1711}
1712
1713static void omap_iommu_release_device(struct device *dev)
1714{
1715	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1716
1717	if (!dev->of_node || !arch_data)
1718		return;
1719
1720	dev_iommu_priv_set(dev, NULL);
1721	kfree(arch_data);
1722
1723}
1724
1725static struct iommu_group *omap_iommu_device_group(struct device *dev)
1726{
1727	struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1728	struct iommu_group *group = ERR_PTR(-EINVAL);
1729
1730	if (!arch_data)
1731		return ERR_PTR(-ENODEV);
1732
1733	if (arch_data->iommu_dev)
1734		group = iommu_group_ref_get(arch_data->iommu_dev->group);
1735
1736	return group;
1737}
1738
1739static const struct iommu_ops omap_iommu_ops = {
1740	.domain_alloc	= omap_iommu_domain_alloc,
1741	.domain_free	= omap_iommu_domain_free,
1742	.attach_dev	= omap_iommu_attach_dev,
1743	.detach_dev	= omap_iommu_detach_dev,
1744	.map		= omap_iommu_map,
1745	.unmap		= omap_iommu_unmap,
1746	.iova_to_phys	= omap_iommu_iova_to_phys,
1747	.probe_device	= omap_iommu_probe_device,
1748	.release_device	= omap_iommu_release_device,
1749	.device_group	= omap_iommu_device_group,
1750	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
1751};
1752
1753static int __init omap_iommu_init(void)
1754{
1755	struct kmem_cache *p;
1756	const slab_flags_t flags = SLAB_HWCACHE_ALIGN;
1757	size_t align = 1 << 10; /* L2 pagetable alignement */
1758	struct device_node *np;
1759	int ret;
1760
1761	np = of_find_matching_node(NULL, omap_iommu_of_match);
1762	if (!np)
1763		return 0;
1764
1765	of_node_put(np);
1766
1767	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
1768			      NULL);
1769	if (!p)
1770		return -ENOMEM;
1771	iopte_cachep = p;
1772
1773	omap_iommu_debugfs_init();
1774
1775	ret = platform_driver_register(&omap_iommu_driver);
1776	if (ret) {
1777		pr_err("%s: failed to register driver\n", __func__);
1778		goto fail_driver;
1779	}
1780
1781	ret = bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
1782	if (ret)
1783		goto fail_bus;
1784
1785	return 0;
1786
1787fail_bus:
1788	platform_driver_unregister(&omap_iommu_driver);
1789fail_driver:
1790	kmem_cache_destroy(iopte_cachep);
1791	return ret;
1792}
1793subsys_initcall(omap_iommu_init);
1794/* must be ready before omap3isp is probed */
1795