xref: /openbmc/linux/drivers/iommu/msm_iommu.c (revision abfd6fe0cd535d31ee83b668be6eb59ce6a8469d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
3  *
4  * Author: Stepan Moskovchenko <stepanm@codeaurora.org>
5  */
6 
7 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/platform_device.h>
11 #include <linux/errno.h>
12 #include <linux/io.h>
13 #include <linux/io-pgtable.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/spinlock.h>
17 #include <linux/slab.h>
18 #include <linux/iommu.h>
19 #include <linux/clk.h>
20 #include <linux/err.h>
21 #include <linux/of_iommu.h>
22 
23 #include <asm/cacheflush.h>
24 #include <linux/sizes.h>
25 
26 #include "msm_iommu_hw-8xxx.h"
27 #include "msm_iommu.h"
28 
29 #define MRC(reg, processor, op1, crn, crm, op2)				\
30 __asm__ __volatile__ (							\
31 "   mrc   "   #processor "," #op1 ", %0,"  #crn "," #crm "," #op2 "\n"  \
32 : "=r" (reg))
33 
34 /* bitmap of the page sizes currently supported */
35 #define MSM_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
36 
37 DEFINE_SPINLOCK(msm_iommu_lock);
38 static LIST_HEAD(qcom_iommu_devices);
39 static struct iommu_ops msm_iommu_ops;
40 
41 struct msm_priv {
42 	struct list_head list_attached;
43 	struct iommu_domain domain;
44 	struct io_pgtable_cfg	cfg;
45 	struct io_pgtable_ops	*iop;
46 	struct device		*dev;
47 	spinlock_t		pgtlock; /* pagetable lock */
48 };
49 
50 static struct msm_priv *to_msm_priv(struct iommu_domain *dom)
51 {
52 	return container_of(dom, struct msm_priv, domain);
53 }
54 
55 static int __enable_clocks(struct msm_iommu_dev *iommu)
56 {
57 	int ret;
58 
59 	ret = clk_enable(iommu->pclk);
60 	if (ret)
61 		goto fail;
62 
63 	if (iommu->clk) {
64 		ret = clk_enable(iommu->clk);
65 		if (ret)
66 			clk_disable(iommu->pclk);
67 	}
68 fail:
69 	return ret;
70 }
71 
72 static void __disable_clocks(struct msm_iommu_dev *iommu)
73 {
74 	if (iommu->clk)
75 		clk_disable(iommu->clk);
76 	clk_disable(iommu->pclk);
77 }
78 
79 static void msm_iommu_reset(void __iomem *base, int ncb)
80 {
81 	int ctx;
82 
83 	SET_RPUE(base, 0);
84 	SET_RPUEIE(base, 0);
85 	SET_ESRRESTORE(base, 0);
86 	SET_TBE(base, 0);
87 	SET_CR(base, 0);
88 	SET_SPDMBE(base, 0);
89 	SET_TESTBUSCR(base, 0);
90 	SET_TLBRSW(base, 0);
91 	SET_GLOBAL_TLBIALL(base, 0);
92 	SET_RPU_ACR(base, 0);
93 	SET_TLBLKCRWE(base, 1);
94 
95 	for (ctx = 0; ctx < ncb; ctx++) {
96 		SET_BPRCOSH(base, ctx, 0);
97 		SET_BPRCISH(base, ctx, 0);
98 		SET_BPRCNSH(base, ctx, 0);
99 		SET_BPSHCFG(base, ctx, 0);
100 		SET_BPMTCFG(base, ctx, 0);
101 		SET_ACTLR(base, ctx, 0);
102 		SET_SCTLR(base, ctx, 0);
103 		SET_FSRRESTORE(base, ctx, 0);
104 		SET_TTBR0(base, ctx, 0);
105 		SET_TTBR1(base, ctx, 0);
106 		SET_TTBCR(base, ctx, 0);
107 		SET_BFBCR(base, ctx, 0);
108 		SET_PAR(base, ctx, 0);
109 		SET_FAR(base, ctx, 0);
110 		SET_CTX_TLBIALL(base, ctx, 0);
111 		SET_TLBFLPTER(base, ctx, 0);
112 		SET_TLBSLPTER(base, ctx, 0);
113 		SET_TLBLKCR(base, ctx, 0);
114 		SET_CONTEXTIDR(base, ctx, 0);
115 	}
116 }
117 
118 static void __flush_iotlb(void *cookie)
119 {
120 	struct msm_priv *priv = cookie;
121 	struct msm_iommu_dev *iommu = NULL;
122 	struct msm_iommu_ctx_dev *master;
123 	int ret = 0;
124 
125 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
126 		ret = __enable_clocks(iommu);
127 		if (ret)
128 			goto fail;
129 
130 		list_for_each_entry(master, &iommu->ctx_list, list)
131 			SET_CTX_TLBIALL(iommu->base, master->num, 0);
132 
133 		__disable_clocks(iommu);
134 	}
135 fail:
136 	return;
137 }
138 
139 static void __flush_iotlb_range(unsigned long iova, size_t size,
140 				size_t granule, bool leaf, void *cookie)
141 {
142 	struct msm_priv *priv = cookie;
143 	struct msm_iommu_dev *iommu = NULL;
144 	struct msm_iommu_ctx_dev *master;
145 	int ret = 0;
146 	int temp_size;
147 
148 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
149 		ret = __enable_clocks(iommu);
150 		if (ret)
151 			goto fail;
152 
153 		list_for_each_entry(master, &iommu->ctx_list, list) {
154 			temp_size = size;
155 			do {
156 				iova &= TLBIVA_VA;
157 				iova |= GET_CONTEXTIDR_ASID(iommu->base,
158 							    master->num);
159 				SET_TLBIVA(iommu->base, master->num, iova);
160 				iova += granule;
161 			} while (temp_size -= granule);
162 		}
163 
164 		__disable_clocks(iommu);
165 	}
166 
167 fail:
168 	return;
169 }
170 
171 static void __flush_iotlb_sync(void *cookie)
172 {
173 	/*
174 	 * Nothing is needed here, the barrier to guarantee
175 	 * completion of the tlb sync operation is implicitly
176 	 * taken care when the iommu client does a writel before
177 	 * kick starting the other master.
178 	 */
179 }
180 
181 static void __flush_iotlb_walk(unsigned long iova, size_t size,
182 			       size_t granule, void *cookie)
183 {
184 	__flush_iotlb_range(iova, size, granule, false, cookie);
185 	__flush_iotlb_sync(cookie);
186 }
187 
188 static void __flush_iotlb_leaf(unsigned long iova, size_t size,
189 			       size_t granule, void *cookie)
190 {
191 	__flush_iotlb_range(iova, size, granule, true, cookie);
192 	__flush_iotlb_sync(cookie);
193 }
194 
195 static void __flush_iotlb_page(unsigned long iova, size_t granule, void *cookie)
196 {
197 	__flush_iotlb_range(iova, granule, granule, true, cookie);
198 }
199 
200 static const struct iommu_flush_ops msm_iommu_flush_ops = {
201 	.tlb_flush_all = __flush_iotlb,
202 	.tlb_flush_walk = __flush_iotlb_walk,
203 	.tlb_flush_leaf = __flush_iotlb_leaf,
204 	.tlb_add_page = __flush_iotlb_page,
205 	.tlb_sync = __flush_iotlb_sync,
206 };
207 
208 static int msm_iommu_alloc_ctx(unsigned long *map, int start, int end)
209 {
210 	int idx;
211 
212 	do {
213 		idx = find_next_zero_bit(map, end, start);
214 		if (idx == end)
215 			return -ENOSPC;
216 	} while (test_and_set_bit(idx, map));
217 
218 	return idx;
219 }
220 
221 static void msm_iommu_free_ctx(unsigned long *map, int idx)
222 {
223 	clear_bit(idx, map);
224 }
225 
226 static void config_mids(struct msm_iommu_dev *iommu,
227 			struct msm_iommu_ctx_dev *master)
228 {
229 	int mid, ctx, i;
230 
231 	for (i = 0; i < master->num_mids; i++) {
232 		mid = master->mids[i];
233 		ctx = master->num;
234 
235 		SET_M2VCBR_N(iommu->base, mid, 0);
236 		SET_CBACR_N(iommu->base, ctx, 0);
237 
238 		/* Set VMID = 0 */
239 		SET_VMID(iommu->base, mid, 0);
240 
241 		/* Set the context number for that MID to this context */
242 		SET_CBNDX(iommu->base, mid, ctx);
243 
244 		/* Set MID associated with this context bank to 0*/
245 		SET_CBVMID(iommu->base, ctx, 0);
246 
247 		/* Set the ASID for TLB tagging for this context */
248 		SET_CONTEXTIDR_ASID(iommu->base, ctx, ctx);
249 
250 		/* Set security bit override to be Non-secure */
251 		SET_NSCFG(iommu->base, mid, 3);
252 	}
253 }
254 
255 static void __reset_context(void __iomem *base, int ctx)
256 {
257 	SET_BPRCOSH(base, ctx, 0);
258 	SET_BPRCISH(base, ctx, 0);
259 	SET_BPRCNSH(base, ctx, 0);
260 	SET_BPSHCFG(base, ctx, 0);
261 	SET_BPMTCFG(base, ctx, 0);
262 	SET_ACTLR(base, ctx, 0);
263 	SET_SCTLR(base, ctx, 0);
264 	SET_FSRRESTORE(base, ctx, 0);
265 	SET_TTBR0(base, ctx, 0);
266 	SET_TTBR1(base, ctx, 0);
267 	SET_TTBCR(base, ctx, 0);
268 	SET_BFBCR(base, ctx, 0);
269 	SET_PAR(base, ctx, 0);
270 	SET_FAR(base, ctx, 0);
271 	SET_CTX_TLBIALL(base, ctx, 0);
272 	SET_TLBFLPTER(base, ctx, 0);
273 	SET_TLBSLPTER(base, ctx, 0);
274 	SET_TLBLKCR(base, ctx, 0);
275 }
276 
277 static void __program_context(void __iomem *base, int ctx,
278 			      struct msm_priv *priv)
279 {
280 	__reset_context(base, ctx);
281 
282 	/* Turn on TEX Remap */
283 	SET_TRE(base, ctx, 1);
284 	SET_AFE(base, ctx, 1);
285 
286 	/* Set up HTW mode */
287 	/* TLB miss configuration: perform HTW on miss */
288 	SET_TLBMCFG(base, ctx, 0x3);
289 
290 	/* V2P configuration: HTW for access */
291 	SET_V2PCFG(base, ctx, 0x3);
292 
293 	SET_TTBCR(base, ctx, priv->cfg.arm_v7s_cfg.tcr);
294 	SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[0]);
295 	SET_TTBR1(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[1]);
296 
297 	/* Set prrr and nmrr */
298 	SET_PRRR(base, ctx, priv->cfg.arm_v7s_cfg.prrr);
299 	SET_NMRR(base, ctx, priv->cfg.arm_v7s_cfg.nmrr);
300 
301 	/* Invalidate the TLB for this context */
302 	SET_CTX_TLBIALL(base, ctx, 0);
303 
304 	/* Set interrupt number to "secure" interrupt */
305 	SET_IRPTNDX(base, ctx, 0);
306 
307 	/* Enable context fault interrupt */
308 	SET_CFEIE(base, ctx, 1);
309 
310 	/* Stall access on a context fault and let the handler deal with it */
311 	SET_CFCFG(base, ctx, 1);
312 
313 	/* Redirect all cacheable requests to L2 slave port. */
314 	SET_RCISH(base, ctx, 1);
315 	SET_RCOSH(base, ctx, 1);
316 	SET_RCNSH(base, ctx, 1);
317 
318 	/* Turn on BFB prefetch */
319 	SET_BFBDFE(base, ctx, 1);
320 
321 	/* Enable the MMU */
322 	SET_M(base, ctx, 1);
323 }
324 
325 static struct iommu_domain *msm_iommu_domain_alloc(unsigned type)
326 {
327 	struct msm_priv *priv;
328 
329 	if (type != IOMMU_DOMAIN_UNMANAGED)
330 		return NULL;
331 
332 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
333 	if (!priv)
334 		goto fail_nomem;
335 
336 	INIT_LIST_HEAD(&priv->list_attached);
337 
338 	priv->domain.geometry.aperture_start = 0;
339 	priv->domain.geometry.aperture_end   = (1ULL << 32) - 1;
340 	priv->domain.geometry.force_aperture = true;
341 
342 	return &priv->domain;
343 
344 fail_nomem:
345 	kfree(priv);
346 	return NULL;
347 }
348 
349 static void msm_iommu_domain_free(struct iommu_domain *domain)
350 {
351 	struct msm_priv *priv;
352 	unsigned long flags;
353 
354 	spin_lock_irqsave(&msm_iommu_lock, flags);
355 	priv = to_msm_priv(domain);
356 	kfree(priv);
357 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
358 }
359 
360 static int msm_iommu_domain_config(struct msm_priv *priv)
361 {
362 	spin_lock_init(&priv->pgtlock);
363 
364 	priv->cfg = (struct io_pgtable_cfg) {
365 		.quirks = IO_PGTABLE_QUIRK_TLBI_ON_MAP,
366 		.pgsize_bitmap = msm_iommu_ops.pgsize_bitmap,
367 		.ias = 32,
368 		.oas = 32,
369 		.tlb = &msm_iommu_flush_ops,
370 		.iommu_dev = priv->dev,
371 	};
372 
373 	priv->iop = alloc_io_pgtable_ops(ARM_V7S, &priv->cfg, priv);
374 	if (!priv->iop) {
375 		dev_err(priv->dev, "Failed to allocate pgtable\n");
376 		return -EINVAL;
377 	}
378 
379 	msm_iommu_ops.pgsize_bitmap = priv->cfg.pgsize_bitmap;
380 
381 	return 0;
382 }
383 
384 /* Must be called under msm_iommu_lock */
385 static struct msm_iommu_dev *find_iommu_for_dev(struct device *dev)
386 {
387 	struct msm_iommu_dev *iommu, *ret = NULL;
388 	struct msm_iommu_ctx_dev *master;
389 
390 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
391 		master = list_first_entry(&iommu->ctx_list,
392 					  struct msm_iommu_ctx_dev,
393 					  list);
394 		if (master->of_node == dev->of_node) {
395 			ret = iommu;
396 			break;
397 		}
398 	}
399 
400 	return ret;
401 }
402 
403 static int msm_iommu_add_device(struct device *dev)
404 {
405 	struct msm_iommu_dev *iommu;
406 	struct iommu_group *group;
407 	unsigned long flags;
408 
409 	spin_lock_irqsave(&msm_iommu_lock, flags);
410 	iommu = find_iommu_for_dev(dev);
411 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
412 
413 	if (iommu)
414 		iommu_device_link(&iommu->iommu, dev);
415 	else
416 		return -ENODEV;
417 
418 	group = iommu_group_get_for_dev(dev);
419 	if (IS_ERR(group))
420 		return PTR_ERR(group);
421 
422 	iommu_group_put(group);
423 
424 	return 0;
425 }
426 
427 static void msm_iommu_remove_device(struct device *dev)
428 {
429 	struct msm_iommu_dev *iommu;
430 	unsigned long flags;
431 
432 	spin_lock_irqsave(&msm_iommu_lock, flags);
433 	iommu = find_iommu_for_dev(dev);
434 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
435 
436 	if (iommu)
437 		iommu_device_unlink(&iommu->iommu, dev);
438 
439 	iommu_group_remove_device(dev);
440 }
441 
442 static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
443 {
444 	int ret = 0;
445 	unsigned long flags;
446 	struct msm_iommu_dev *iommu;
447 	struct msm_priv *priv = to_msm_priv(domain);
448 	struct msm_iommu_ctx_dev *master;
449 
450 	priv->dev = dev;
451 	msm_iommu_domain_config(priv);
452 
453 	spin_lock_irqsave(&msm_iommu_lock, flags);
454 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
455 		master = list_first_entry(&iommu->ctx_list,
456 					  struct msm_iommu_ctx_dev,
457 					  list);
458 		if (master->of_node == dev->of_node) {
459 			ret = __enable_clocks(iommu);
460 			if (ret)
461 				goto fail;
462 
463 			list_for_each_entry(master, &iommu->ctx_list, list) {
464 				if (master->num) {
465 					dev_err(dev, "domain already attached");
466 					ret = -EEXIST;
467 					goto fail;
468 				}
469 				master->num =
470 					msm_iommu_alloc_ctx(iommu->context_map,
471 							    0, iommu->ncb);
472 				if (IS_ERR_VALUE(master->num)) {
473 					ret = -ENODEV;
474 					goto fail;
475 				}
476 				config_mids(iommu, master);
477 				__program_context(iommu->base, master->num,
478 						  priv);
479 			}
480 			__disable_clocks(iommu);
481 			list_add(&iommu->dom_node, &priv->list_attached);
482 		}
483 	}
484 
485 fail:
486 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
487 
488 	return ret;
489 }
490 
491 static void msm_iommu_detach_dev(struct iommu_domain *domain,
492 				 struct device *dev)
493 {
494 	struct msm_priv *priv = to_msm_priv(domain);
495 	unsigned long flags;
496 	struct msm_iommu_dev *iommu;
497 	struct msm_iommu_ctx_dev *master;
498 	int ret;
499 
500 	free_io_pgtable_ops(priv->iop);
501 
502 	spin_lock_irqsave(&msm_iommu_lock, flags);
503 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
504 		ret = __enable_clocks(iommu);
505 		if (ret)
506 			goto fail;
507 
508 		list_for_each_entry(master, &iommu->ctx_list, list) {
509 			msm_iommu_free_ctx(iommu->context_map, master->num);
510 			__reset_context(iommu->base, master->num);
511 		}
512 		__disable_clocks(iommu);
513 	}
514 fail:
515 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
516 }
517 
518 static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
519 			 phys_addr_t pa, size_t len, int prot)
520 {
521 	struct msm_priv *priv = to_msm_priv(domain);
522 	unsigned long flags;
523 	int ret;
524 
525 	spin_lock_irqsave(&priv->pgtlock, flags);
526 	ret = priv->iop->map(priv->iop, iova, pa, len, prot);
527 	spin_unlock_irqrestore(&priv->pgtlock, flags);
528 
529 	return ret;
530 }
531 
532 static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
533 			      size_t len, struct iommu_iotlb_gather *gather)
534 {
535 	struct msm_priv *priv = to_msm_priv(domain);
536 	unsigned long flags;
537 
538 	spin_lock_irqsave(&priv->pgtlock, flags);
539 	len = priv->iop->unmap(priv->iop, iova, len);
540 	spin_unlock_irqrestore(&priv->pgtlock, flags);
541 
542 	return len;
543 }
544 
545 static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
546 					  dma_addr_t va)
547 {
548 	struct msm_priv *priv;
549 	struct msm_iommu_dev *iommu;
550 	struct msm_iommu_ctx_dev *master;
551 	unsigned int par;
552 	unsigned long flags;
553 	phys_addr_t ret = 0;
554 
555 	spin_lock_irqsave(&msm_iommu_lock, flags);
556 
557 	priv = to_msm_priv(domain);
558 	iommu = list_first_entry(&priv->list_attached,
559 				 struct msm_iommu_dev, dom_node);
560 
561 	if (list_empty(&iommu->ctx_list))
562 		goto fail;
563 
564 	master = list_first_entry(&iommu->ctx_list,
565 				  struct msm_iommu_ctx_dev, list);
566 	if (!master)
567 		goto fail;
568 
569 	ret = __enable_clocks(iommu);
570 	if (ret)
571 		goto fail;
572 
573 	/* Invalidate context TLB */
574 	SET_CTX_TLBIALL(iommu->base, master->num, 0);
575 	SET_V2PPR(iommu->base, master->num, va & V2Pxx_VA);
576 
577 	par = GET_PAR(iommu->base, master->num);
578 
579 	/* We are dealing with a supersection */
580 	if (GET_NOFAULT_SS(iommu->base, master->num))
581 		ret = (par & 0xFF000000) | (va & 0x00FFFFFF);
582 	else	/* Upper 20 bits from PAR, lower 12 from VA */
583 		ret = (par & 0xFFFFF000) | (va & 0x00000FFF);
584 
585 	if (GET_FAULT(iommu->base, master->num))
586 		ret = 0;
587 
588 	__disable_clocks(iommu);
589 fail:
590 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
591 	return ret;
592 }
593 
594 static bool msm_iommu_capable(enum iommu_cap cap)
595 {
596 	return false;
597 }
598 
599 static void print_ctx_regs(void __iomem *base, int ctx)
600 {
601 	unsigned int fsr = GET_FSR(base, ctx);
602 	pr_err("FAR    = %08x    PAR    = %08x\n",
603 	       GET_FAR(base, ctx), GET_PAR(base, ctx));
604 	pr_err("FSR    = %08x [%s%s%s%s%s%s%s%s%s%s]\n", fsr,
605 			(fsr & 0x02) ? "TF " : "",
606 			(fsr & 0x04) ? "AFF " : "",
607 			(fsr & 0x08) ? "APF " : "",
608 			(fsr & 0x10) ? "TLBMF " : "",
609 			(fsr & 0x20) ? "HTWDEEF " : "",
610 			(fsr & 0x40) ? "HTWSEEF " : "",
611 			(fsr & 0x80) ? "MHF " : "",
612 			(fsr & 0x10000) ? "SL " : "",
613 			(fsr & 0x40000000) ? "SS " : "",
614 			(fsr & 0x80000000) ? "MULTI " : "");
615 
616 	pr_err("FSYNR0 = %08x    FSYNR1 = %08x\n",
617 	       GET_FSYNR0(base, ctx), GET_FSYNR1(base, ctx));
618 	pr_err("TTBR0  = %08x    TTBR1  = %08x\n",
619 	       GET_TTBR0(base, ctx), GET_TTBR1(base, ctx));
620 	pr_err("SCTLR  = %08x    ACTLR  = %08x\n",
621 	       GET_SCTLR(base, ctx), GET_ACTLR(base, ctx));
622 }
623 
624 static void insert_iommu_master(struct device *dev,
625 				struct msm_iommu_dev **iommu,
626 				struct of_phandle_args *spec)
627 {
628 	struct msm_iommu_ctx_dev *master = dev->archdata.iommu;
629 	int sid;
630 
631 	if (list_empty(&(*iommu)->ctx_list)) {
632 		master = kzalloc(sizeof(*master), GFP_ATOMIC);
633 		master->of_node = dev->of_node;
634 		list_add(&master->list, &(*iommu)->ctx_list);
635 		dev->archdata.iommu = master;
636 	}
637 
638 	for (sid = 0; sid < master->num_mids; sid++)
639 		if (master->mids[sid] == spec->args[0]) {
640 			dev_warn(dev, "Stream ID 0x%hx repeated; ignoring\n",
641 				 sid);
642 			return;
643 		}
644 
645 	master->mids[master->num_mids++] = spec->args[0];
646 }
647 
648 static int qcom_iommu_of_xlate(struct device *dev,
649 			       struct of_phandle_args *spec)
650 {
651 	struct msm_iommu_dev *iommu;
652 	unsigned long flags;
653 	int ret = 0;
654 
655 	spin_lock_irqsave(&msm_iommu_lock, flags);
656 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
657 		if (iommu->dev->of_node == spec->np)
658 			break;
659 
660 	if (!iommu || iommu->dev->of_node != spec->np) {
661 		ret = -ENODEV;
662 		goto fail;
663 	}
664 
665 	insert_iommu_master(dev, &iommu, spec);
666 fail:
667 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
668 
669 	return ret;
670 }
671 
672 irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
673 {
674 	struct msm_iommu_dev *iommu = dev_id;
675 	unsigned int fsr;
676 	int i, ret;
677 
678 	spin_lock(&msm_iommu_lock);
679 
680 	if (!iommu) {
681 		pr_err("Invalid device ID in context interrupt handler\n");
682 		goto fail;
683 	}
684 
685 	pr_err("Unexpected IOMMU page fault!\n");
686 	pr_err("base = %08x\n", (unsigned int)iommu->base);
687 
688 	ret = __enable_clocks(iommu);
689 	if (ret)
690 		goto fail;
691 
692 	for (i = 0; i < iommu->ncb; i++) {
693 		fsr = GET_FSR(iommu->base, i);
694 		if (fsr) {
695 			pr_err("Fault occurred in context %d.\n", i);
696 			pr_err("Interesting registers:\n");
697 			print_ctx_regs(iommu->base, i);
698 			SET_FSR(iommu->base, i, 0x4000000F);
699 		}
700 	}
701 	__disable_clocks(iommu);
702 fail:
703 	spin_unlock(&msm_iommu_lock);
704 	return 0;
705 }
706 
707 static struct iommu_ops msm_iommu_ops = {
708 	.capable = msm_iommu_capable,
709 	.domain_alloc = msm_iommu_domain_alloc,
710 	.domain_free = msm_iommu_domain_free,
711 	.attach_dev = msm_iommu_attach_dev,
712 	.detach_dev = msm_iommu_detach_dev,
713 	.map = msm_iommu_map,
714 	.unmap = msm_iommu_unmap,
715 	.iova_to_phys = msm_iommu_iova_to_phys,
716 	.add_device = msm_iommu_add_device,
717 	.remove_device = msm_iommu_remove_device,
718 	.device_group = generic_device_group,
719 	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
720 	.of_xlate = qcom_iommu_of_xlate,
721 };
722 
723 static int msm_iommu_probe(struct platform_device *pdev)
724 {
725 	struct resource *r;
726 	resource_size_t ioaddr;
727 	struct msm_iommu_dev *iommu;
728 	int ret, par, val;
729 
730 	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
731 	if (!iommu)
732 		return -ENODEV;
733 
734 	iommu->dev = &pdev->dev;
735 	INIT_LIST_HEAD(&iommu->ctx_list);
736 
737 	iommu->pclk = devm_clk_get(iommu->dev, "smmu_pclk");
738 	if (IS_ERR(iommu->pclk)) {
739 		dev_err(iommu->dev, "could not get smmu_pclk\n");
740 		return PTR_ERR(iommu->pclk);
741 	}
742 
743 	ret = clk_prepare(iommu->pclk);
744 	if (ret) {
745 		dev_err(iommu->dev, "could not prepare smmu_pclk\n");
746 		return ret;
747 	}
748 
749 	iommu->clk = devm_clk_get(iommu->dev, "iommu_clk");
750 	if (IS_ERR(iommu->clk)) {
751 		dev_err(iommu->dev, "could not get iommu_clk\n");
752 		clk_unprepare(iommu->pclk);
753 		return PTR_ERR(iommu->clk);
754 	}
755 
756 	ret = clk_prepare(iommu->clk);
757 	if (ret) {
758 		dev_err(iommu->dev, "could not prepare iommu_clk\n");
759 		clk_unprepare(iommu->pclk);
760 		return ret;
761 	}
762 
763 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
764 	iommu->base = devm_ioremap_resource(iommu->dev, r);
765 	if (IS_ERR(iommu->base)) {
766 		dev_err(iommu->dev, "could not get iommu base\n");
767 		ret = PTR_ERR(iommu->base);
768 		goto fail;
769 	}
770 	ioaddr = r->start;
771 
772 	iommu->irq = platform_get_irq(pdev, 0);
773 	if (iommu->irq < 0) {
774 		dev_err(iommu->dev, "could not get iommu irq\n");
775 		ret = -ENODEV;
776 		goto fail;
777 	}
778 
779 	ret = of_property_read_u32(iommu->dev->of_node, "qcom,ncb", &val);
780 	if (ret) {
781 		dev_err(iommu->dev, "could not get ncb\n");
782 		goto fail;
783 	}
784 	iommu->ncb = val;
785 
786 	msm_iommu_reset(iommu->base, iommu->ncb);
787 	SET_M(iommu->base, 0, 1);
788 	SET_PAR(iommu->base, 0, 0);
789 	SET_V2PCFG(iommu->base, 0, 1);
790 	SET_V2PPR(iommu->base, 0, 0);
791 	par = GET_PAR(iommu->base, 0);
792 	SET_V2PCFG(iommu->base, 0, 0);
793 	SET_M(iommu->base, 0, 0);
794 
795 	if (!par) {
796 		pr_err("Invalid PAR value detected\n");
797 		ret = -ENODEV;
798 		goto fail;
799 	}
800 
801 	ret = devm_request_threaded_irq(iommu->dev, iommu->irq, NULL,
802 					msm_iommu_fault_handler,
803 					IRQF_ONESHOT | IRQF_SHARED,
804 					"msm_iommu_secure_irpt_handler",
805 					iommu);
806 	if (ret) {
807 		pr_err("Request IRQ %d failed with ret=%d\n", iommu->irq, ret);
808 		goto fail;
809 	}
810 
811 	list_add(&iommu->dev_node, &qcom_iommu_devices);
812 
813 	ret = iommu_device_sysfs_add(&iommu->iommu, iommu->dev, NULL,
814 				     "msm-smmu.%pa", &ioaddr);
815 	if (ret) {
816 		pr_err("Could not add msm-smmu at %pa to sysfs\n", &ioaddr);
817 		goto fail;
818 	}
819 
820 	iommu_device_set_ops(&iommu->iommu, &msm_iommu_ops);
821 	iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
822 
823 	ret = iommu_device_register(&iommu->iommu);
824 	if (ret) {
825 		pr_err("Could not register msm-smmu at %pa\n", &ioaddr);
826 		goto fail;
827 	}
828 
829 	bus_set_iommu(&platform_bus_type, &msm_iommu_ops);
830 
831 	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
832 		iommu->base, iommu->irq, iommu->ncb);
833 
834 	return ret;
835 fail:
836 	clk_unprepare(iommu->clk);
837 	clk_unprepare(iommu->pclk);
838 	return ret;
839 }
840 
841 static const struct of_device_id msm_iommu_dt_match[] = {
842 	{ .compatible = "qcom,apq8064-iommu" },
843 	{}
844 };
845 
846 static int msm_iommu_remove(struct platform_device *pdev)
847 {
848 	struct msm_iommu_dev *iommu = platform_get_drvdata(pdev);
849 
850 	clk_unprepare(iommu->clk);
851 	clk_unprepare(iommu->pclk);
852 	return 0;
853 }
854 
855 static struct platform_driver msm_iommu_driver = {
856 	.driver = {
857 		.name	= "msm_iommu",
858 		.of_match_table = msm_iommu_dt_match,
859 	},
860 	.probe		= msm_iommu_probe,
861 	.remove		= msm_iommu_remove,
862 };
863 
864 static int __init msm_iommu_driver_init(void)
865 {
866 	int ret;
867 
868 	ret = platform_driver_register(&msm_iommu_driver);
869 	if (ret != 0)
870 		pr_err("Failed to register IOMMU driver\n");
871 
872 	return ret;
873 }
874 subsys_initcall(msm_iommu_driver_init);
875 
876