xref: /openbmc/linux/drivers/iommu/msm_iommu.c (revision 2cf1c348)
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 
22 #include <asm/cacheflush.h>
23 #include <linux/sizes.h>
24 
25 #include "msm_iommu_hw-8xxx.h"
26 #include "msm_iommu.h"
27 
28 #define MRC(reg, processor, op1, crn, crm, op2)				\
29 __asm__ __volatile__ (							\
30 "   mrc   "   #processor "," #op1 ", %0,"  #crn "," #crm "," #op2 "\n"  \
31 : "=r" (reg))
32 
33 /* bitmap of the page sizes currently supported */
34 #define MSM_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
35 
36 static DEFINE_SPINLOCK(msm_iommu_lock);
37 static LIST_HEAD(qcom_iommu_devices);
38 static struct iommu_ops msm_iommu_ops;
39 
40 struct msm_priv {
41 	struct list_head list_attached;
42 	struct iommu_domain domain;
43 	struct io_pgtable_cfg	cfg;
44 	struct io_pgtable_ops	*iop;
45 	struct device		*dev;
46 	spinlock_t		pgtlock; /* pagetable lock */
47 };
48 
49 static struct msm_priv *to_msm_priv(struct iommu_domain *dom)
50 {
51 	return container_of(dom, struct msm_priv, domain);
52 }
53 
54 static int __enable_clocks(struct msm_iommu_dev *iommu)
55 {
56 	int ret;
57 
58 	ret = clk_enable(iommu->pclk);
59 	if (ret)
60 		goto fail;
61 
62 	if (iommu->clk) {
63 		ret = clk_enable(iommu->clk);
64 		if (ret)
65 			clk_disable(iommu->pclk);
66 	}
67 fail:
68 	return ret;
69 }
70 
71 static void __disable_clocks(struct msm_iommu_dev *iommu)
72 {
73 	if (iommu->clk)
74 		clk_disable(iommu->clk);
75 	clk_disable(iommu->pclk);
76 }
77 
78 static void msm_iommu_reset(void __iomem *base, int ncb)
79 {
80 	int ctx;
81 
82 	SET_RPUE(base, 0);
83 	SET_RPUEIE(base, 0);
84 	SET_ESRRESTORE(base, 0);
85 	SET_TBE(base, 0);
86 	SET_CR(base, 0);
87 	SET_SPDMBE(base, 0);
88 	SET_TESTBUSCR(base, 0);
89 	SET_TLBRSW(base, 0);
90 	SET_GLOBAL_TLBIALL(base, 0);
91 	SET_RPU_ACR(base, 0);
92 	SET_TLBLKCRWE(base, 1);
93 
94 	for (ctx = 0; ctx < ncb; ctx++) {
95 		SET_BPRCOSH(base, ctx, 0);
96 		SET_BPRCISH(base, ctx, 0);
97 		SET_BPRCNSH(base, ctx, 0);
98 		SET_BPSHCFG(base, ctx, 0);
99 		SET_BPMTCFG(base, ctx, 0);
100 		SET_ACTLR(base, ctx, 0);
101 		SET_SCTLR(base, ctx, 0);
102 		SET_FSRRESTORE(base, ctx, 0);
103 		SET_TTBR0(base, ctx, 0);
104 		SET_TTBR1(base, ctx, 0);
105 		SET_TTBCR(base, ctx, 0);
106 		SET_BFBCR(base, ctx, 0);
107 		SET_PAR(base, ctx, 0);
108 		SET_FAR(base, ctx, 0);
109 		SET_CTX_TLBIALL(base, ctx, 0);
110 		SET_TLBFLPTER(base, ctx, 0);
111 		SET_TLBSLPTER(base, ctx, 0);
112 		SET_TLBLKCR(base, ctx, 0);
113 		SET_CONTEXTIDR(base, ctx, 0);
114 	}
115 }
116 
117 static void __flush_iotlb(void *cookie)
118 {
119 	struct msm_priv *priv = cookie;
120 	struct msm_iommu_dev *iommu = NULL;
121 	struct msm_iommu_ctx_dev *master;
122 	int ret = 0;
123 
124 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
125 		ret = __enable_clocks(iommu);
126 		if (ret)
127 			goto fail;
128 
129 		list_for_each_entry(master, &iommu->ctx_list, list)
130 			SET_CTX_TLBIALL(iommu->base, master->num, 0);
131 
132 		__disable_clocks(iommu);
133 	}
134 fail:
135 	return;
136 }
137 
138 static void __flush_iotlb_range(unsigned long iova, size_t size,
139 				size_t granule, bool leaf, void *cookie)
140 {
141 	struct msm_priv *priv = cookie;
142 	struct msm_iommu_dev *iommu = NULL;
143 	struct msm_iommu_ctx_dev *master;
144 	int ret = 0;
145 	int temp_size;
146 
147 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
148 		ret = __enable_clocks(iommu);
149 		if (ret)
150 			goto fail;
151 
152 		list_for_each_entry(master, &iommu->ctx_list, list) {
153 			temp_size = size;
154 			do {
155 				iova &= TLBIVA_VA;
156 				iova |= GET_CONTEXTIDR_ASID(iommu->base,
157 							    master->num);
158 				SET_TLBIVA(iommu->base, master->num, iova);
159 				iova += granule;
160 			} while (temp_size -= granule);
161 		}
162 
163 		__disable_clocks(iommu);
164 	}
165 
166 fail:
167 	return;
168 }
169 
170 static void __flush_iotlb_walk(unsigned long iova, size_t size,
171 			       size_t granule, void *cookie)
172 {
173 	__flush_iotlb_range(iova, size, granule, false, cookie);
174 }
175 
176 static void __flush_iotlb_page(struct iommu_iotlb_gather *gather,
177 			       unsigned long iova, size_t granule, void *cookie)
178 {
179 	__flush_iotlb_range(iova, granule, granule, true, cookie);
180 }
181 
182 static const struct iommu_flush_ops msm_iommu_flush_ops = {
183 	.tlb_flush_all = __flush_iotlb,
184 	.tlb_flush_walk = __flush_iotlb_walk,
185 	.tlb_add_page = __flush_iotlb_page,
186 };
187 
188 static int msm_iommu_alloc_ctx(unsigned long *map, int start, int end)
189 {
190 	int idx;
191 
192 	do {
193 		idx = find_next_zero_bit(map, end, start);
194 		if (idx == end)
195 			return -ENOSPC;
196 	} while (test_and_set_bit(idx, map));
197 
198 	return idx;
199 }
200 
201 static void msm_iommu_free_ctx(unsigned long *map, int idx)
202 {
203 	clear_bit(idx, map);
204 }
205 
206 static void config_mids(struct msm_iommu_dev *iommu,
207 			struct msm_iommu_ctx_dev *master)
208 {
209 	int mid, ctx, i;
210 
211 	for (i = 0; i < master->num_mids; i++) {
212 		mid = master->mids[i];
213 		ctx = master->num;
214 
215 		SET_M2VCBR_N(iommu->base, mid, 0);
216 		SET_CBACR_N(iommu->base, ctx, 0);
217 
218 		/* Set VMID = 0 */
219 		SET_VMID(iommu->base, mid, 0);
220 
221 		/* Set the context number for that MID to this context */
222 		SET_CBNDX(iommu->base, mid, ctx);
223 
224 		/* Set MID associated with this context bank to 0*/
225 		SET_CBVMID(iommu->base, ctx, 0);
226 
227 		/* Set the ASID for TLB tagging for this context */
228 		SET_CONTEXTIDR_ASID(iommu->base, ctx, ctx);
229 
230 		/* Set security bit override to be Non-secure */
231 		SET_NSCFG(iommu->base, mid, 3);
232 	}
233 }
234 
235 static void __reset_context(void __iomem *base, int ctx)
236 {
237 	SET_BPRCOSH(base, ctx, 0);
238 	SET_BPRCISH(base, ctx, 0);
239 	SET_BPRCNSH(base, ctx, 0);
240 	SET_BPSHCFG(base, ctx, 0);
241 	SET_BPMTCFG(base, ctx, 0);
242 	SET_ACTLR(base, ctx, 0);
243 	SET_SCTLR(base, ctx, 0);
244 	SET_FSRRESTORE(base, ctx, 0);
245 	SET_TTBR0(base, ctx, 0);
246 	SET_TTBR1(base, ctx, 0);
247 	SET_TTBCR(base, ctx, 0);
248 	SET_BFBCR(base, ctx, 0);
249 	SET_PAR(base, ctx, 0);
250 	SET_FAR(base, ctx, 0);
251 	SET_CTX_TLBIALL(base, ctx, 0);
252 	SET_TLBFLPTER(base, ctx, 0);
253 	SET_TLBSLPTER(base, ctx, 0);
254 	SET_TLBLKCR(base, ctx, 0);
255 }
256 
257 static void __program_context(void __iomem *base, int ctx,
258 			      struct msm_priv *priv)
259 {
260 	__reset_context(base, ctx);
261 
262 	/* Turn on TEX Remap */
263 	SET_TRE(base, ctx, 1);
264 	SET_AFE(base, ctx, 1);
265 
266 	/* Set up HTW mode */
267 	/* TLB miss configuration: perform HTW on miss */
268 	SET_TLBMCFG(base, ctx, 0x3);
269 
270 	/* V2P configuration: HTW for access */
271 	SET_V2PCFG(base, ctx, 0x3);
272 
273 	SET_TTBCR(base, ctx, priv->cfg.arm_v7s_cfg.tcr);
274 	SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr);
275 	SET_TTBR1(base, ctx, 0);
276 
277 	/* Set prrr and nmrr */
278 	SET_PRRR(base, ctx, priv->cfg.arm_v7s_cfg.prrr);
279 	SET_NMRR(base, ctx, priv->cfg.arm_v7s_cfg.nmrr);
280 
281 	/* Invalidate the TLB for this context */
282 	SET_CTX_TLBIALL(base, ctx, 0);
283 
284 	/* Set interrupt number to "secure" interrupt */
285 	SET_IRPTNDX(base, ctx, 0);
286 
287 	/* Enable context fault interrupt */
288 	SET_CFEIE(base, ctx, 1);
289 
290 	/* Stall access on a context fault and let the handler deal with it */
291 	SET_CFCFG(base, ctx, 1);
292 
293 	/* Redirect all cacheable requests to L2 slave port. */
294 	SET_RCISH(base, ctx, 1);
295 	SET_RCOSH(base, ctx, 1);
296 	SET_RCNSH(base, ctx, 1);
297 
298 	/* Turn on BFB prefetch */
299 	SET_BFBDFE(base, ctx, 1);
300 
301 	/* Enable the MMU */
302 	SET_M(base, ctx, 1);
303 }
304 
305 static struct iommu_domain *msm_iommu_domain_alloc(unsigned type)
306 {
307 	struct msm_priv *priv;
308 
309 	if (type != IOMMU_DOMAIN_UNMANAGED)
310 		return NULL;
311 
312 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
313 	if (!priv)
314 		goto fail_nomem;
315 
316 	INIT_LIST_HEAD(&priv->list_attached);
317 
318 	priv->domain.geometry.aperture_start = 0;
319 	priv->domain.geometry.aperture_end   = (1ULL << 32) - 1;
320 	priv->domain.geometry.force_aperture = true;
321 
322 	return &priv->domain;
323 
324 fail_nomem:
325 	kfree(priv);
326 	return NULL;
327 }
328 
329 static void msm_iommu_domain_free(struct iommu_domain *domain)
330 {
331 	struct msm_priv *priv;
332 	unsigned long flags;
333 
334 	spin_lock_irqsave(&msm_iommu_lock, flags);
335 	priv = to_msm_priv(domain);
336 	kfree(priv);
337 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
338 }
339 
340 static int msm_iommu_domain_config(struct msm_priv *priv)
341 {
342 	spin_lock_init(&priv->pgtlock);
343 
344 	priv->cfg = (struct io_pgtable_cfg) {
345 		.pgsize_bitmap = msm_iommu_ops.pgsize_bitmap,
346 		.ias = 32,
347 		.oas = 32,
348 		.tlb = &msm_iommu_flush_ops,
349 		.iommu_dev = priv->dev,
350 	};
351 
352 	priv->iop = alloc_io_pgtable_ops(ARM_V7S, &priv->cfg, priv);
353 	if (!priv->iop) {
354 		dev_err(priv->dev, "Failed to allocate pgtable\n");
355 		return -EINVAL;
356 	}
357 
358 	msm_iommu_ops.pgsize_bitmap = priv->cfg.pgsize_bitmap;
359 
360 	return 0;
361 }
362 
363 /* Must be called under msm_iommu_lock */
364 static struct msm_iommu_dev *find_iommu_for_dev(struct device *dev)
365 {
366 	struct msm_iommu_dev *iommu, *ret = NULL;
367 	struct msm_iommu_ctx_dev *master;
368 
369 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
370 		master = list_first_entry(&iommu->ctx_list,
371 					  struct msm_iommu_ctx_dev,
372 					  list);
373 		if (master->of_node == dev->of_node) {
374 			ret = iommu;
375 			break;
376 		}
377 	}
378 
379 	return ret;
380 }
381 
382 static struct iommu_device *msm_iommu_probe_device(struct device *dev)
383 {
384 	struct msm_iommu_dev *iommu;
385 	unsigned long flags;
386 
387 	spin_lock_irqsave(&msm_iommu_lock, flags);
388 	iommu = find_iommu_for_dev(dev);
389 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
390 
391 	if (!iommu)
392 		return ERR_PTR(-ENODEV);
393 
394 	return &iommu->iommu;
395 }
396 
397 static void msm_iommu_release_device(struct device *dev)
398 {
399 }
400 
401 static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
402 {
403 	int ret = 0;
404 	unsigned long flags;
405 	struct msm_iommu_dev *iommu;
406 	struct msm_priv *priv = to_msm_priv(domain);
407 	struct msm_iommu_ctx_dev *master;
408 
409 	priv->dev = dev;
410 	msm_iommu_domain_config(priv);
411 
412 	spin_lock_irqsave(&msm_iommu_lock, flags);
413 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
414 		master = list_first_entry(&iommu->ctx_list,
415 					  struct msm_iommu_ctx_dev,
416 					  list);
417 		if (master->of_node == dev->of_node) {
418 			ret = __enable_clocks(iommu);
419 			if (ret)
420 				goto fail;
421 
422 			list_for_each_entry(master, &iommu->ctx_list, list) {
423 				if (master->num) {
424 					dev_err(dev, "domain already attached");
425 					ret = -EEXIST;
426 					goto fail;
427 				}
428 				master->num =
429 					msm_iommu_alloc_ctx(iommu->context_map,
430 							    0, iommu->ncb);
431 				if (IS_ERR_VALUE(master->num)) {
432 					ret = -ENODEV;
433 					goto fail;
434 				}
435 				config_mids(iommu, master);
436 				__program_context(iommu->base, master->num,
437 						  priv);
438 			}
439 			__disable_clocks(iommu);
440 			list_add(&iommu->dom_node, &priv->list_attached);
441 		}
442 	}
443 
444 fail:
445 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
446 
447 	return ret;
448 }
449 
450 static void msm_iommu_detach_dev(struct iommu_domain *domain,
451 				 struct device *dev)
452 {
453 	struct msm_priv *priv = to_msm_priv(domain);
454 	unsigned long flags;
455 	struct msm_iommu_dev *iommu;
456 	struct msm_iommu_ctx_dev *master;
457 	int ret;
458 
459 	free_io_pgtable_ops(priv->iop);
460 
461 	spin_lock_irqsave(&msm_iommu_lock, flags);
462 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
463 		ret = __enable_clocks(iommu);
464 		if (ret)
465 			goto fail;
466 
467 		list_for_each_entry(master, &iommu->ctx_list, list) {
468 			msm_iommu_free_ctx(iommu->context_map, master->num);
469 			__reset_context(iommu->base, master->num);
470 		}
471 		__disable_clocks(iommu);
472 	}
473 fail:
474 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
475 }
476 
477 static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
478 			 phys_addr_t pa, size_t len, int prot, gfp_t gfp)
479 {
480 	struct msm_priv *priv = to_msm_priv(domain);
481 	unsigned long flags;
482 	int ret;
483 
484 	spin_lock_irqsave(&priv->pgtlock, flags);
485 	ret = priv->iop->map(priv->iop, iova, pa, len, prot, GFP_ATOMIC);
486 	spin_unlock_irqrestore(&priv->pgtlock, flags);
487 
488 	return ret;
489 }
490 
491 static void msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
492 			       size_t size)
493 {
494 	struct msm_priv *priv = to_msm_priv(domain);
495 
496 	__flush_iotlb_range(iova, size, SZ_4K, false, priv);
497 }
498 
499 static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
500 			      size_t len, struct iommu_iotlb_gather *gather)
501 {
502 	struct msm_priv *priv = to_msm_priv(domain);
503 	unsigned long flags;
504 
505 	spin_lock_irqsave(&priv->pgtlock, flags);
506 	len = priv->iop->unmap(priv->iop, iova, len, gather);
507 	spin_unlock_irqrestore(&priv->pgtlock, flags);
508 
509 	return len;
510 }
511 
512 static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
513 					  dma_addr_t va)
514 {
515 	struct msm_priv *priv;
516 	struct msm_iommu_dev *iommu;
517 	struct msm_iommu_ctx_dev *master;
518 	unsigned int par;
519 	unsigned long flags;
520 	phys_addr_t ret = 0;
521 
522 	spin_lock_irqsave(&msm_iommu_lock, flags);
523 
524 	priv = to_msm_priv(domain);
525 	iommu = list_first_entry(&priv->list_attached,
526 				 struct msm_iommu_dev, dom_node);
527 
528 	if (list_empty(&iommu->ctx_list))
529 		goto fail;
530 
531 	master = list_first_entry(&iommu->ctx_list,
532 				  struct msm_iommu_ctx_dev, list);
533 	if (!master)
534 		goto fail;
535 
536 	ret = __enable_clocks(iommu);
537 	if (ret)
538 		goto fail;
539 
540 	/* Invalidate context TLB */
541 	SET_CTX_TLBIALL(iommu->base, master->num, 0);
542 	SET_V2PPR(iommu->base, master->num, va & V2Pxx_VA);
543 
544 	par = GET_PAR(iommu->base, master->num);
545 
546 	/* We are dealing with a supersection */
547 	if (GET_NOFAULT_SS(iommu->base, master->num))
548 		ret = (par & 0xFF000000) | (va & 0x00FFFFFF);
549 	else	/* Upper 20 bits from PAR, lower 12 from VA */
550 		ret = (par & 0xFFFFF000) | (va & 0x00000FFF);
551 
552 	if (GET_FAULT(iommu->base, master->num))
553 		ret = 0;
554 
555 	__disable_clocks(iommu);
556 fail:
557 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
558 	return ret;
559 }
560 
561 static bool msm_iommu_capable(enum iommu_cap cap)
562 {
563 	return false;
564 }
565 
566 static void print_ctx_regs(void __iomem *base, int ctx)
567 {
568 	unsigned int fsr = GET_FSR(base, ctx);
569 	pr_err("FAR    = %08x    PAR    = %08x\n",
570 	       GET_FAR(base, ctx), GET_PAR(base, ctx));
571 	pr_err("FSR    = %08x [%s%s%s%s%s%s%s%s%s%s]\n", fsr,
572 			(fsr & 0x02) ? "TF " : "",
573 			(fsr & 0x04) ? "AFF " : "",
574 			(fsr & 0x08) ? "APF " : "",
575 			(fsr & 0x10) ? "TLBMF " : "",
576 			(fsr & 0x20) ? "HTWDEEF " : "",
577 			(fsr & 0x40) ? "HTWSEEF " : "",
578 			(fsr & 0x80) ? "MHF " : "",
579 			(fsr & 0x10000) ? "SL " : "",
580 			(fsr & 0x40000000) ? "SS " : "",
581 			(fsr & 0x80000000) ? "MULTI " : "");
582 
583 	pr_err("FSYNR0 = %08x    FSYNR1 = %08x\n",
584 	       GET_FSYNR0(base, ctx), GET_FSYNR1(base, ctx));
585 	pr_err("TTBR0  = %08x    TTBR1  = %08x\n",
586 	       GET_TTBR0(base, ctx), GET_TTBR1(base, ctx));
587 	pr_err("SCTLR  = %08x    ACTLR  = %08x\n",
588 	       GET_SCTLR(base, ctx), GET_ACTLR(base, ctx));
589 }
590 
591 static void insert_iommu_master(struct device *dev,
592 				struct msm_iommu_dev **iommu,
593 				struct of_phandle_args *spec)
594 {
595 	struct msm_iommu_ctx_dev *master = dev_iommu_priv_get(dev);
596 	int sid;
597 
598 	if (list_empty(&(*iommu)->ctx_list)) {
599 		master = kzalloc(sizeof(*master), GFP_ATOMIC);
600 		master->of_node = dev->of_node;
601 		list_add(&master->list, &(*iommu)->ctx_list);
602 		dev_iommu_priv_set(dev, master);
603 	}
604 
605 	for (sid = 0; sid < master->num_mids; sid++)
606 		if (master->mids[sid] == spec->args[0]) {
607 			dev_warn(dev, "Stream ID 0x%hx repeated; ignoring\n",
608 				 sid);
609 			return;
610 		}
611 
612 	master->mids[master->num_mids++] = spec->args[0];
613 }
614 
615 static int qcom_iommu_of_xlate(struct device *dev,
616 			       struct of_phandle_args *spec)
617 {
618 	struct msm_iommu_dev *iommu;
619 	unsigned long flags;
620 	int ret = 0;
621 
622 	spin_lock_irqsave(&msm_iommu_lock, flags);
623 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
624 		if (iommu->dev->of_node == spec->np)
625 			break;
626 
627 	if (!iommu || iommu->dev->of_node != spec->np) {
628 		ret = -ENODEV;
629 		goto fail;
630 	}
631 
632 	insert_iommu_master(dev, &iommu, spec);
633 fail:
634 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
635 
636 	return ret;
637 }
638 
639 irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
640 {
641 	struct msm_iommu_dev *iommu = dev_id;
642 	unsigned int fsr;
643 	int i, ret;
644 
645 	spin_lock(&msm_iommu_lock);
646 
647 	if (!iommu) {
648 		pr_err("Invalid device ID in context interrupt handler\n");
649 		goto fail;
650 	}
651 
652 	pr_err("Unexpected IOMMU page fault!\n");
653 	pr_err("base = %08x\n", (unsigned int)iommu->base);
654 
655 	ret = __enable_clocks(iommu);
656 	if (ret)
657 		goto fail;
658 
659 	for (i = 0; i < iommu->ncb; i++) {
660 		fsr = GET_FSR(iommu->base, i);
661 		if (fsr) {
662 			pr_err("Fault occurred in context %d.\n", i);
663 			pr_err("Interesting registers:\n");
664 			print_ctx_regs(iommu->base, i);
665 			SET_FSR(iommu->base, i, 0x4000000F);
666 		}
667 	}
668 	__disable_clocks(iommu);
669 fail:
670 	spin_unlock(&msm_iommu_lock);
671 	return 0;
672 }
673 
674 static struct iommu_ops msm_iommu_ops = {
675 	.capable = msm_iommu_capable,
676 	.domain_alloc = msm_iommu_domain_alloc,
677 	.domain_free = msm_iommu_domain_free,
678 	.attach_dev = msm_iommu_attach_dev,
679 	.detach_dev = msm_iommu_detach_dev,
680 	.map = msm_iommu_map,
681 	.unmap = msm_iommu_unmap,
682 	/*
683 	 * Nothing is needed here, the barrier to guarantee
684 	 * completion of the tlb sync operation is implicitly
685 	 * taken care when the iommu client does a writel before
686 	 * kick starting the other master.
687 	 */
688 	.iotlb_sync = NULL,
689 	.iotlb_sync_map = msm_iommu_sync_map,
690 	.iova_to_phys = msm_iommu_iova_to_phys,
691 	.probe_device = msm_iommu_probe_device,
692 	.release_device = msm_iommu_release_device,
693 	.device_group = generic_device_group,
694 	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
695 	.of_xlate = qcom_iommu_of_xlate,
696 };
697 
698 static int msm_iommu_probe(struct platform_device *pdev)
699 {
700 	struct resource *r;
701 	resource_size_t ioaddr;
702 	struct msm_iommu_dev *iommu;
703 	int ret, par, val;
704 
705 	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
706 	if (!iommu)
707 		return -ENODEV;
708 
709 	iommu->dev = &pdev->dev;
710 	INIT_LIST_HEAD(&iommu->ctx_list);
711 
712 	iommu->pclk = devm_clk_get(iommu->dev, "smmu_pclk");
713 	if (IS_ERR(iommu->pclk)) {
714 		dev_err(iommu->dev, "could not get smmu_pclk\n");
715 		return PTR_ERR(iommu->pclk);
716 	}
717 
718 	ret = clk_prepare(iommu->pclk);
719 	if (ret) {
720 		dev_err(iommu->dev, "could not prepare smmu_pclk\n");
721 		return ret;
722 	}
723 
724 	iommu->clk = devm_clk_get(iommu->dev, "iommu_clk");
725 	if (IS_ERR(iommu->clk)) {
726 		dev_err(iommu->dev, "could not get iommu_clk\n");
727 		clk_unprepare(iommu->pclk);
728 		return PTR_ERR(iommu->clk);
729 	}
730 
731 	ret = clk_prepare(iommu->clk);
732 	if (ret) {
733 		dev_err(iommu->dev, "could not prepare iommu_clk\n");
734 		clk_unprepare(iommu->pclk);
735 		return ret;
736 	}
737 
738 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
739 	iommu->base = devm_ioremap_resource(iommu->dev, r);
740 	if (IS_ERR(iommu->base)) {
741 		dev_err(iommu->dev, "could not get iommu base\n");
742 		ret = PTR_ERR(iommu->base);
743 		goto fail;
744 	}
745 	ioaddr = r->start;
746 
747 	iommu->irq = platform_get_irq(pdev, 0);
748 	if (iommu->irq < 0) {
749 		ret = -ENODEV;
750 		goto fail;
751 	}
752 
753 	ret = of_property_read_u32(iommu->dev->of_node, "qcom,ncb", &val);
754 	if (ret) {
755 		dev_err(iommu->dev, "could not get ncb\n");
756 		goto fail;
757 	}
758 	iommu->ncb = val;
759 
760 	msm_iommu_reset(iommu->base, iommu->ncb);
761 	SET_M(iommu->base, 0, 1);
762 	SET_PAR(iommu->base, 0, 0);
763 	SET_V2PCFG(iommu->base, 0, 1);
764 	SET_V2PPR(iommu->base, 0, 0);
765 	par = GET_PAR(iommu->base, 0);
766 	SET_V2PCFG(iommu->base, 0, 0);
767 	SET_M(iommu->base, 0, 0);
768 
769 	if (!par) {
770 		pr_err("Invalid PAR value detected\n");
771 		ret = -ENODEV;
772 		goto fail;
773 	}
774 
775 	ret = devm_request_threaded_irq(iommu->dev, iommu->irq, NULL,
776 					msm_iommu_fault_handler,
777 					IRQF_ONESHOT | IRQF_SHARED,
778 					"msm_iommu_secure_irpt_handler",
779 					iommu);
780 	if (ret) {
781 		pr_err("Request IRQ %d failed with ret=%d\n", iommu->irq, ret);
782 		goto fail;
783 	}
784 
785 	list_add(&iommu->dev_node, &qcom_iommu_devices);
786 
787 	ret = iommu_device_sysfs_add(&iommu->iommu, iommu->dev, NULL,
788 				     "msm-smmu.%pa", &ioaddr);
789 	if (ret) {
790 		pr_err("Could not add msm-smmu at %pa to sysfs\n", &ioaddr);
791 		goto fail;
792 	}
793 
794 	ret = iommu_device_register(&iommu->iommu, &msm_iommu_ops, &pdev->dev);
795 	if (ret) {
796 		pr_err("Could not register msm-smmu at %pa\n", &ioaddr);
797 		goto fail;
798 	}
799 
800 	bus_set_iommu(&platform_bus_type, &msm_iommu_ops);
801 
802 	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
803 		iommu->base, iommu->irq, iommu->ncb);
804 
805 	return ret;
806 fail:
807 	clk_unprepare(iommu->clk);
808 	clk_unprepare(iommu->pclk);
809 	return ret;
810 }
811 
812 static const struct of_device_id msm_iommu_dt_match[] = {
813 	{ .compatible = "qcom,apq8064-iommu" },
814 	{}
815 };
816 
817 static int msm_iommu_remove(struct platform_device *pdev)
818 {
819 	struct msm_iommu_dev *iommu = platform_get_drvdata(pdev);
820 
821 	clk_unprepare(iommu->clk);
822 	clk_unprepare(iommu->pclk);
823 	return 0;
824 }
825 
826 static struct platform_driver msm_iommu_driver = {
827 	.driver = {
828 		.name	= "msm_iommu",
829 		.of_match_table = msm_iommu_dt_match,
830 	},
831 	.probe		= msm_iommu_probe,
832 	.remove		= msm_iommu_remove,
833 };
834 
835 static int __init msm_iommu_driver_init(void)
836 {
837 	int ret;
838 
839 	ret = platform_driver_register(&msm_iommu_driver);
840 	if (ret != 0)
841 		pr_err("Failed to register IOMMU driver\n");
842 
843 	return ret;
844 }
845 subsys_initcall(msm_iommu_driver_init);
846 
847