1/*
2 * IPMMU VMSA
3 *
4 * Copyright (C) 2014 Renesas Electronics Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 */
10
11#include <linux/delay.h>
12#include <linux/dma-mapping.h>
13#include <linux/err.h>
14#include <linux/export.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/iommu.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/platform_device.h>
21#include <linux/sizes.h>
22#include <linux/slab.h>
23
24#include <asm/dma-iommu.h>
25#include <asm/pgalloc.h>
26
27#include "io-pgtable.h"
28
29struct ipmmu_vmsa_device {
30	struct device *dev;
31	void __iomem *base;
32	struct list_head list;
33
34	unsigned int num_utlbs;
35
36	struct dma_iommu_mapping *mapping;
37};
38
39struct ipmmu_vmsa_domain {
40	struct ipmmu_vmsa_device *mmu;
41	struct iommu_domain io_domain;
42
43	struct io_pgtable_cfg cfg;
44	struct io_pgtable_ops *iop;
45
46	unsigned int context_id;
47	spinlock_t lock;			/* Protects mappings */
48};
49
50struct ipmmu_vmsa_archdata {
51	struct ipmmu_vmsa_device *mmu;
52	unsigned int *utlbs;
53	unsigned int num_utlbs;
54};
55
56static DEFINE_SPINLOCK(ipmmu_devices_lock);
57static LIST_HEAD(ipmmu_devices);
58
59static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
60{
61	return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
62}
63
64#define TLB_LOOP_TIMEOUT		100	/* 100us */
65
66/* -----------------------------------------------------------------------------
67 * Registers Definition
68 */
69
70#define IM_NS_ALIAS_OFFSET		0x800
71
72#define IM_CTX_SIZE			0x40
73
74#define IMCTR				0x0000
75#define IMCTR_TRE			(1 << 17)
76#define IMCTR_AFE			(1 << 16)
77#define IMCTR_RTSEL_MASK		(3 << 4)
78#define IMCTR_RTSEL_SHIFT		4
79#define IMCTR_TREN			(1 << 3)
80#define IMCTR_INTEN			(1 << 2)
81#define IMCTR_FLUSH			(1 << 1)
82#define IMCTR_MMUEN			(1 << 0)
83
84#define IMCAAR				0x0004
85
86#define IMTTBCR				0x0008
87#define IMTTBCR_EAE			(1 << 31)
88#define IMTTBCR_PMB			(1 << 30)
89#define IMTTBCR_SH1_NON_SHAREABLE	(0 << 28)
90#define IMTTBCR_SH1_OUTER_SHAREABLE	(2 << 28)
91#define IMTTBCR_SH1_INNER_SHAREABLE	(3 << 28)
92#define IMTTBCR_SH1_MASK		(3 << 28)
93#define IMTTBCR_ORGN1_NC		(0 << 26)
94#define IMTTBCR_ORGN1_WB_WA		(1 << 26)
95#define IMTTBCR_ORGN1_WT		(2 << 26)
96#define IMTTBCR_ORGN1_WB		(3 << 26)
97#define IMTTBCR_ORGN1_MASK		(3 << 26)
98#define IMTTBCR_IRGN1_NC		(0 << 24)
99#define IMTTBCR_IRGN1_WB_WA		(1 << 24)
100#define IMTTBCR_IRGN1_WT		(2 << 24)
101#define IMTTBCR_IRGN1_WB		(3 << 24)
102#define IMTTBCR_IRGN1_MASK		(3 << 24)
103#define IMTTBCR_TSZ1_MASK		(7 << 16)
104#define IMTTBCR_TSZ1_SHIFT		16
105#define IMTTBCR_SH0_NON_SHAREABLE	(0 << 12)
106#define IMTTBCR_SH0_OUTER_SHAREABLE	(2 << 12)
107#define IMTTBCR_SH0_INNER_SHAREABLE	(3 << 12)
108#define IMTTBCR_SH0_MASK		(3 << 12)
109#define IMTTBCR_ORGN0_NC		(0 << 10)
110#define IMTTBCR_ORGN0_WB_WA		(1 << 10)
111#define IMTTBCR_ORGN0_WT		(2 << 10)
112#define IMTTBCR_ORGN0_WB		(3 << 10)
113#define IMTTBCR_ORGN0_MASK		(3 << 10)
114#define IMTTBCR_IRGN0_NC		(0 << 8)
115#define IMTTBCR_IRGN0_WB_WA		(1 << 8)
116#define IMTTBCR_IRGN0_WT		(2 << 8)
117#define IMTTBCR_IRGN0_WB		(3 << 8)
118#define IMTTBCR_IRGN0_MASK		(3 << 8)
119#define IMTTBCR_SL0_LVL_2		(0 << 4)
120#define IMTTBCR_SL0_LVL_1		(1 << 4)
121#define IMTTBCR_TSZ0_MASK		(7 << 0)
122#define IMTTBCR_TSZ0_SHIFT		O
123
124#define IMBUSCR				0x000c
125#define IMBUSCR_DVM			(1 << 2)
126#define IMBUSCR_BUSSEL_SYS		(0 << 0)
127#define IMBUSCR_BUSSEL_CCI		(1 << 0)
128#define IMBUSCR_BUSSEL_IMCAAR		(2 << 0)
129#define IMBUSCR_BUSSEL_CCI_IMCAAR	(3 << 0)
130#define IMBUSCR_BUSSEL_MASK		(3 << 0)
131
132#define IMTTLBR0			0x0010
133#define IMTTUBR0			0x0014
134#define IMTTLBR1			0x0018
135#define IMTTUBR1			0x001c
136
137#define IMSTR				0x0020
138#define IMSTR_ERRLVL_MASK		(3 << 12)
139#define IMSTR_ERRLVL_SHIFT		12
140#define IMSTR_ERRCODE_TLB_FORMAT	(1 << 8)
141#define IMSTR_ERRCODE_ACCESS_PERM	(4 << 8)
142#define IMSTR_ERRCODE_SECURE_ACCESS	(5 << 8)
143#define IMSTR_ERRCODE_MASK		(7 << 8)
144#define IMSTR_MHIT			(1 << 4)
145#define IMSTR_ABORT			(1 << 2)
146#define IMSTR_PF			(1 << 1)
147#define IMSTR_TF			(1 << 0)
148
149#define IMMAIR0				0x0028
150#define IMMAIR1				0x002c
151#define IMMAIR_ATTR_MASK		0xff
152#define IMMAIR_ATTR_DEVICE		0x04
153#define IMMAIR_ATTR_NC			0x44
154#define IMMAIR_ATTR_WBRWA		0xff
155#define IMMAIR_ATTR_SHIFT(n)		((n) << 3)
156#define IMMAIR_ATTR_IDX_NC		0
157#define IMMAIR_ATTR_IDX_WBRWA		1
158#define IMMAIR_ATTR_IDX_DEV		2
159
160#define IMEAR				0x0030
161
162#define IMPCTR				0x0200
163#define IMPSTR				0x0208
164#define IMPEAR				0x020c
165#define IMPMBA(n)			(0x0280 + ((n) * 4))
166#define IMPMBD(n)			(0x02c0 + ((n) * 4))
167
168#define IMUCTR(n)			(0x0300 + ((n) * 16))
169#define IMUCTR_FIXADDEN			(1 << 31)
170#define IMUCTR_FIXADD_MASK		(0xff << 16)
171#define IMUCTR_FIXADD_SHIFT		16
172#define IMUCTR_TTSEL_MMU(n)		((n) << 4)
173#define IMUCTR_TTSEL_PMB		(8 << 4)
174#define IMUCTR_TTSEL_MASK		(15 << 4)
175#define IMUCTR_FLUSH			(1 << 1)
176#define IMUCTR_MMUEN			(1 << 0)
177
178#define IMUASID(n)			(0x0308 + ((n) * 16))
179#define IMUASID_ASID8_MASK		(0xff << 8)
180#define IMUASID_ASID8_SHIFT		8
181#define IMUASID_ASID0_MASK		(0xff << 0)
182#define IMUASID_ASID0_SHIFT		0
183
184/* -----------------------------------------------------------------------------
185 * Read/Write Access
186 */
187
188static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
189{
190	return ioread32(mmu->base + offset);
191}
192
193static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
194			u32 data)
195{
196	iowrite32(data, mmu->base + offset);
197}
198
199static u32 ipmmu_ctx_read(struct ipmmu_vmsa_domain *domain, unsigned int reg)
200{
201	return ipmmu_read(domain->mmu, domain->context_id * IM_CTX_SIZE + reg);
202}
203
204static void ipmmu_ctx_write(struct ipmmu_vmsa_domain *domain, unsigned int reg,
205			    u32 data)
206{
207	ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg, data);
208}
209
210/* -----------------------------------------------------------------------------
211 * TLB and microTLB Management
212 */
213
214/* Wait for any pending TLB invalidations to complete */
215static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
216{
217	unsigned int count = 0;
218
219	while (ipmmu_ctx_read(domain, IMCTR) & IMCTR_FLUSH) {
220		cpu_relax();
221		if (++count == TLB_LOOP_TIMEOUT) {
222			dev_err_ratelimited(domain->mmu->dev,
223			"TLB sync timed out -- MMU may be deadlocked\n");
224			return;
225		}
226		udelay(1);
227	}
228}
229
230static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
231{
232	u32 reg;
233
234	reg = ipmmu_ctx_read(domain, IMCTR);
235	reg |= IMCTR_FLUSH;
236	ipmmu_ctx_write(domain, IMCTR, reg);
237
238	ipmmu_tlb_sync(domain);
239}
240
241/*
242 * Enable MMU translation for the microTLB.
243 */
244static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
245			      unsigned int utlb)
246{
247	struct ipmmu_vmsa_device *mmu = domain->mmu;
248
249	/*
250	 * TODO: Reference-count the microTLB as several bus masters can be
251	 * connected to the same microTLB.
252	 */
253
254	/* TODO: What should we set the ASID to ? */
255	ipmmu_write(mmu, IMUASID(utlb), 0);
256	/* TODO: Do we need to flush the microTLB ? */
257	ipmmu_write(mmu, IMUCTR(utlb),
258		    IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
259		    IMUCTR_MMUEN);
260}
261
262/*
263 * Disable MMU translation for the microTLB.
264 */
265static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
266			       unsigned int utlb)
267{
268	struct ipmmu_vmsa_device *mmu = domain->mmu;
269
270	ipmmu_write(mmu, IMUCTR(utlb), 0);
271}
272
273static void ipmmu_tlb_flush_all(void *cookie)
274{
275	struct ipmmu_vmsa_domain *domain = cookie;
276
277	ipmmu_tlb_invalidate(domain);
278}
279
280static void ipmmu_tlb_add_flush(unsigned long iova, size_t size, bool leaf,
281				void *cookie)
282{
283	/* The hardware doesn't support selective TLB flush. */
284}
285
286static struct iommu_gather_ops ipmmu_gather_ops = {
287	.tlb_flush_all = ipmmu_tlb_flush_all,
288	.tlb_add_flush = ipmmu_tlb_add_flush,
289	.tlb_sync = ipmmu_tlb_flush_all,
290};
291
292/* -----------------------------------------------------------------------------
293 * Domain/Context Management
294 */
295
296static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
297{
298	u64 ttbr;
299
300	/*
301	 * Allocate the page table operations.
302	 *
303	 * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
304	 * access, Long-descriptor format" that the NStable bit being set in a
305	 * table descriptor will result in the NStable and NS bits of all child
306	 * entries being ignored and considered as being set. The IPMMU seems
307	 * not to comply with this, as it generates a secure access page fault
308	 * if any of the NStable and NS bits isn't set when running in
309	 * non-secure mode.
310	 */
311	domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
312	domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
313	domain->cfg.ias = 32;
314	domain->cfg.oas = 40;
315	domain->cfg.tlb = &ipmmu_gather_ops;
316	/*
317	 * TODO: Add support for coherent walk through CCI with DVM and remove
318	 * cache handling. For now, delegate it to the io-pgtable code.
319	 */
320	domain->cfg.iommu_dev = domain->mmu->dev;
321
322	domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
323					   domain);
324	if (!domain->iop)
325		return -EINVAL;
326
327	/*
328	 * TODO: When adding support for multiple contexts, find an unused
329	 * context.
330	 */
331	domain->context_id = 0;
332
333	/* TTBR0 */
334	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
335	ipmmu_ctx_write(domain, IMTTLBR0, ttbr);
336	ipmmu_ctx_write(domain, IMTTUBR0, ttbr >> 32);
337
338	/*
339	 * TTBCR
340	 * We use long descriptors with inner-shareable WBWA tables and allocate
341	 * the whole 32-bit VA space to TTBR0.
342	 */
343	ipmmu_ctx_write(domain, IMTTBCR, IMTTBCR_EAE |
344			IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
345			IMTTBCR_IRGN0_WB_WA | IMTTBCR_SL0_LVL_1);
346
347	/* MAIR0 */
348	ipmmu_ctx_write(domain, IMMAIR0, domain->cfg.arm_lpae_s1_cfg.mair[0]);
349
350	/* IMBUSCR */
351	ipmmu_ctx_write(domain, IMBUSCR,
352			ipmmu_ctx_read(domain, IMBUSCR) &
353			~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
354
355	/*
356	 * IMSTR
357	 * Clear all interrupt flags.
358	 */
359	ipmmu_ctx_write(domain, IMSTR, ipmmu_ctx_read(domain, IMSTR));
360
361	/*
362	 * IMCTR
363	 * Enable the MMU and interrupt generation. The long-descriptor
364	 * translation table format doesn't use TEX remapping. Don't enable AF
365	 * software management as we have no use for it. Flush the TLB as
366	 * required when modifying the context registers.
367	 */
368	ipmmu_ctx_write(domain, IMCTR, IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
369
370	return 0;
371}
372
373static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
374{
375	/*
376	 * Disable the context. Flush the TLB as required when modifying the
377	 * context registers.
378	 *
379	 * TODO: Is TLB flush really needed ?
380	 */
381	ipmmu_ctx_write(domain, IMCTR, IMCTR_FLUSH);
382	ipmmu_tlb_sync(domain);
383}
384
385/* -----------------------------------------------------------------------------
386 * Fault Handling
387 */
388
389static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
390{
391	const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
392	struct ipmmu_vmsa_device *mmu = domain->mmu;
393	u32 status;
394	u32 iova;
395
396	status = ipmmu_ctx_read(domain, IMSTR);
397	if (!(status & err_mask))
398		return IRQ_NONE;
399
400	iova = ipmmu_ctx_read(domain, IMEAR);
401
402	/*
403	 * Clear the error status flags. Unlike traditional interrupt flag
404	 * registers that must be cleared by writing 1, this status register
405	 * seems to require 0. The error address register must be read before,
406	 * otherwise its value will be 0.
407	 */
408	ipmmu_ctx_write(domain, IMSTR, 0);
409
410	/* Log fatal errors. */
411	if (status & IMSTR_MHIT)
412		dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%08x\n",
413				    iova);
414	if (status & IMSTR_ABORT)
415		dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%08x\n",
416				    iova);
417
418	if (!(status & (IMSTR_PF | IMSTR_TF)))
419		return IRQ_NONE;
420
421	/*
422	 * Try to handle page faults and translation faults.
423	 *
424	 * TODO: We need to look up the faulty device based on the I/O VA. Use
425	 * the IOMMU device for now.
426	 */
427	if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
428		return IRQ_HANDLED;
429
430	dev_err_ratelimited(mmu->dev,
431			    "Unhandled fault: status 0x%08x iova 0x%08x\n",
432			    status, iova);
433
434	return IRQ_HANDLED;
435}
436
437static irqreturn_t ipmmu_irq(int irq, void *dev)
438{
439	struct ipmmu_vmsa_device *mmu = dev;
440	struct iommu_domain *io_domain;
441	struct ipmmu_vmsa_domain *domain;
442
443	if (!mmu->mapping)
444		return IRQ_NONE;
445
446	io_domain = mmu->mapping->domain;
447	domain = to_vmsa_domain(io_domain);
448
449	return ipmmu_domain_irq(domain);
450}
451
452/* -----------------------------------------------------------------------------
453 * IOMMU Operations
454 */
455
456static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
457{
458	struct ipmmu_vmsa_domain *domain;
459
460	if (type != IOMMU_DOMAIN_UNMANAGED)
461		return NULL;
462
463	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
464	if (!domain)
465		return NULL;
466
467	spin_lock_init(&domain->lock);
468
469	return &domain->io_domain;
470}
471
472static void ipmmu_domain_free(struct iommu_domain *io_domain)
473{
474	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
475
476	/*
477	 * Free the domain resources. We assume that all devices have already
478	 * been detached.
479	 */
480	ipmmu_domain_destroy_context(domain);
481	free_io_pgtable_ops(domain->iop);
482	kfree(domain);
483}
484
485static int ipmmu_attach_device(struct iommu_domain *io_domain,
486			       struct device *dev)
487{
488	struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
489	struct ipmmu_vmsa_device *mmu = archdata->mmu;
490	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
491	unsigned long flags;
492	unsigned int i;
493	int ret = 0;
494
495	if (!mmu) {
496		dev_err(dev, "Cannot attach to IPMMU\n");
497		return -ENXIO;
498	}
499
500	spin_lock_irqsave(&domain->lock, flags);
501
502	if (!domain->mmu) {
503		/* The domain hasn't been used yet, initialize it. */
504		domain->mmu = mmu;
505		ret = ipmmu_domain_init_context(domain);
506	} else if (domain->mmu != mmu) {
507		/*
508		 * Something is wrong, we can't attach two devices using
509		 * different IOMMUs to the same domain.
510		 */
511		dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
512			dev_name(mmu->dev), dev_name(domain->mmu->dev));
513		ret = -EINVAL;
514	}
515
516	spin_unlock_irqrestore(&domain->lock, flags);
517
518	if (ret < 0)
519		return ret;
520
521	for (i = 0; i < archdata->num_utlbs; ++i)
522		ipmmu_utlb_enable(domain, archdata->utlbs[i]);
523
524	return 0;
525}
526
527static void ipmmu_detach_device(struct iommu_domain *io_domain,
528				struct device *dev)
529{
530	struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
531	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
532	unsigned int i;
533
534	for (i = 0; i < archdata->num_utlbs; ++i)
535		ipmmu_utlb_disable(domain, archdata->utlbs[i]);
536
537	/*
538	 * TODO: Optimize by disabling the context when no device is attached.
539	 */
540}
541
542static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
543		     phys_addr_t paddr, size_t size, int prot)
544{
545	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
546
547	if (!domain)
548		return -ENODEV;
549
550	return domain->iop->map(domain->iop, iova, paddr, size, prot);
551}
552
553static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
554			  size_t size)
555{
556	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
557
558	return domain->iop->unmap(domain->iop, iova, size);
559}
560
561static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
562				      dma_addr_t iova)
563{
564	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
565
566	/* TODO: Is locking needed ? */
567
568	return domain->iop->iova_to_phys(domain->iop, iova);
569}
570
571static int ipmmu_find_utlbs(struct ipmmu_vmsa_device *mmu, struct device *dev,
572			    unsigned int *utlbs, unsigned int num_utlbs)
573{
574	unsigned int i;
575
576	for (i = 0; i < num_utlbs; ++i) {
577		struct of_phandle_args args;
578		int ret;
579
580		ret = of_parse_phandle_with_args(dev->of_node, "iommus",
581						 "#iommu-cells", i, &args);
582		if (ret < 0)
583			return ret;
584
585		of_node_put(args.np);
586
587		if (args.np != mmu->dev->of_node || args.args_count != 1)
588			return -EINVAL;
589
590		utlbs[i] = args.args[0];
591	}
592
593	return 0;
594}
595
596static int ipmmu_add_device(struct device *dev)
597{
598	struct ipmmu_vmsa_archdata *archdata;
599	struct ipmmu_vmsa_device *mmu;
600	struct iommu_group *group = NULL;
601	unsigned int *utlbs;
602	unsigned int i;
603	int num_utlbs;
604	int ret = -ENODEV;
605
606	if (dev->archdata.iommu) {
607		dev_warn(dev, "IOMMU driver already assigned to device %s\n",
608			 dev_name(dev));
609		return -EINVAL;
610	}
611
612	/* Find the master corresponding to the device. */
613
614	num_utlbs = of_count_phandle_with_args(dev->of_node, "iommus",
615					       "#iommu-cells");
616	if (num_utlbs < 0)
617		return -ENODEV;
618
619	utlbs = kcalloc(num_utlbs, sizeof(*utlbs), GFP_KERNEL);
620	if (!utlbs)
621		return -ENOMEM;
622
623	spin_lock(&ipmmu_devices_lock);
624
625	list_for_each_entry(mmu, &ipmmu_devices, list) {
626		ret = ipmmu_find_utlbs(mmu, dev, utlbs, num_utlbs);
627		if (!ret) {
628			/*
629			 * TODO Take a reference to the MMU to protect
630			 * against device removal.
631			 */
632			break;
633		}
634	}
635
636	spin_unlock(&ipmmu_devices_lock);
637
638	if (ret < 0)
639		return -ENODEV;
640
641	for (i = 0; i < num_utlbs; ++i) {
642		if (utlbs[i] >= mmu->num_utlbs) {
643			ret = -EINVAL;
644			goto error;
645		}
646	}
647
648	/* Create a device group and add the device to it. */
649	group = iommu_group_alloc();
650	if (IS_ERR(group)) {
651		dev_err(dev, "Failed to allocate IOMMU group\n");
652		ret = PTR_ERR(group);
653		goto error;
654	}
655
656	ret = iommu_group_add_device(group, dev);
657	iommu_group_put(group);
658
659	if (ret < 0) {
660		dev_err(dev, "Failed to add device to IPMMU group\n");
661		group = NULL;
662		goto error;
663	}
664
665	archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
666	if (!archdata) {
667		ret = -ENOMEM;
668		goto error;
669	}
670
671	archdata->mmu = mmu;
672	archdata->utlbs = utlbs;
673	archdata->num_utlbs = num_utlbs;
674	dev->archdata.iommu = archdata;
675
676	/*
677	 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
678	 * VAs. This will allocate a corresponding IOMMU domain.
679	 *
680	 * TODO:
681	 * - Create one mapping per context (TLB).
682	 * - Make the mapping size configurable ? We currently use a 2GB mapping
683	 *   at a 1GB offset to ensure that NULL VAs will fault.
684	 */
685	if (!mmu->mapping) {
686		struct dma_iommu_mapping *mapping;
687
688		mapping = arm_iommu_create_mapping(&platform_bus_type,
689						   SZ_1G, SZ_2G);
690		if (IS_ERR(mapping)) {
691			dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
692			ret = PTR_ERR(mapping);
693			goto error;
694		}
695
696		mmu->mapping = mapping;
697	}
698
699	/* Attach the ARM VA mapping to the device. */
700	ret = arm_iommu_attach_device(dev, mmu->mapping);
701	if (ret < 0) {
702		dev_err(dev, "Failed to attach device to VA mapping\n");
703		goto error;
704	}
705
706	return 0;
707
708error:
709	arm_iommu_release_mapping(mmu->mapping);
710
711	kfree(dev->archdata.iommu);
712	kfree(utlbs);
713
714	dev->archdata.iommu = NULL;
715
716	if (!IS_ERR_OR_NULL(group))
717		iommu_group_remove_device(dev);
718
719	return ret;
720}
721
722static void ipmmu_remove_device(struct device *dev)
723{
724	struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
725
726	arm_iommu_detach_device(dev);
727	iommu_group_remove_device(dev);
728
729	kfree(archdata->utlbs);
730	kfree(archdata);
731
732	dev->archdata.iommu = NULL;
733}
734
735static const struct iommu_ops ipmmu_ops = {
736	.domain_alloc = ipmmu_domain_alloc,
737	.domain_free = ipmmu_domain_free,
738	.attach_dev = ipmmu_attach_device,
739	.detach_dev = ipmmu_detach_device,
740	.map = ipmmu_map,
741	.unmap = ipmmu_unmap,
742	.map_sg = default_iommu_map_sg,
743	.iova_to_phys = ipmmu_iova_to_phys,
744	.add_device = ipmmu_add_device,
745	.remove_device = ipmmu_remove_device,
746	.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
747};
748
749/* -----------------------------------------------------------------------------
750 * Probe/remove and init
751 */
752
753static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
754{
755	unsigned int i;
756
757	/* Disable all contexts. */
758	for (i = 0; i < 4; ++i)
759		ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
760}
761
762static int ipmmu_probe(struct platform_device *pdev)
763{
764	struct ipmmu_vmsa_device *mmu;
765	struct resource *res;
766	int irq;
767	int ret;
768
769	if (!IS_ENABLED(CONFIG_OF) && !pdev->dev.platform_data) {
770		dev_err(&pdev->dev, "missing platform data\n");
771		return -EINVAL;
772	}
773
774	mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
775	if (!mmu) {
776		dev_err(&pdev->dev, "cannot allocate device data\n");
777		return -ENOMEM;
778	}
779
780	mmu->dev = &pdev->dev;
781	mmu->num_utlbs = 32;
782
783	/* Map I/O memory and request IRQ. */
784	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
785	mmu->base = devm_ioremap_resource(&pdev->dev, res);
786	if (IS_ERR(mmu->base))
787		return PTR_ERR(mmu->base);
788
789	/*
790	 * The IPMMU has two register banks, for secure and non-secure modes.
791	 * The bank mapped at the beginning of the IPMMU address space
792	 * corresponds to the running mode of the CPU. When running in secure
793	 * mode the non-secure register bank is also available at an offset.
794	 *
795	 * Secure mode operation isn't clearly documented and is thus currently
796	 * not implemented in the driver. Furthermore, preliminary tests of
797	 * non-secure operation with the main register bank were not successful.
798	 * Offset the registers base unconditionally to point to the non-secure
799	 * alias space for now.
800	 */
801	mmu->base += IM_NS_ALIAS_OFFSET;
802
803	irq = platform_get_irq(pdev, 0);
804	if (irq < 0) {
805		dev_err(&pdev->dev, "no IRQ found\n");
806		return irq;
807	}
808
809	ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
810			       dev_name(&pdev->dev), mmu);
811	if (ret < 0) {
812		dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
813		return ret;
814	}
815
816	ipmmu_device_reset(mmu);
817
818	/*
819	 * We can't create the ARM mapping here as it requires the bus to have
820	 * an IOMMU, which only happens when bus_set_iommu() is called in
821	 * ipmmu_init() after the probe function returns.
822	 */
823
824	spin_lock(&ipmmu_devices_lock);
825	list_add(&mmu->list, &ipmmu_devices);
826	spin_unlock(&ipmmu_devices_lock);
827
828	platform_set_drvdata(pdev, mmu);
829
830	return 0;
831}
832
833static int ipmmu_remove(struct platform_device *pdev)
834{
835	struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
836
837	spin_lock(&ipmmu_devices_lock);
838	list_del(&mmu->list);
839	spin_unlock(&ipmmu_devices_lock);
840
841	arm_iommu_release_mapping(mmu->mapping);
842
843	ipmmu_device_reset(mmu);
844
845	return 0;
846}
847
848static const struct of_device_id ipmmu_of_ids[] = {
849	{ .compatible = "renesas,ipmmu-vmsa", },
850	{ }
851};
852
853static struct platform_driver ipmmu_driver = {
854	.driver = {
855		.name = "ipmmu-vmsa",
856		.of_match_table = of_match_ptr(ipmmu_of_ids),
857	},
858	.probe = ipmmu_probe,
859	.remove	= ipmmu_remove,
860};
861
862static int __init ipmmu_init(void)
863{
864	int ret;
865
866	ret = platform_driver_register(&ipmmu_driver);
867	if (ret < 0)
868		return ret;
869
870	if (!iommu_present(&platform_bus_type))
871		bus_set_iommu(&platform_bus_type, &ipmmu_ops);
872
873	return 0;
874}
875
876static void __exit ipmmu_exit(void)
877{
878	return platform_driver_unregister(&ipmmu_driver);
879}
880
881subsys_initcall(ipmmu_init);
882module_exit(ipmmu_exit);
883
884MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
885MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
886MODULE_LICENSE("GPL v2");
887