xref: /openbmc/linux/drivers/iommu/msm_iommu.c (revision 20e2fc42)
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_walk(unsigned long iova, size_t size,
172 			       size_t granule, void *cookie)
173 {
174 	__flush_iotlb_range(iova, size, granule, false, cookie);
175 }
176 
177 static void __flush_iotlb_leaf(unsigned long iova, size_t size,
178 			       size_t granule, void *cookie)
179 {
180 	__flush_iotlb_range(iova, size, granule, true, cookie);
181 }
182 
183 static void __flush_iotlb_page(struct iommu_iotlb_gather *gather,
184 			       unsigned long iova, size_t granule, void *cookie)
185 {
186 	__flush_iotlb_range(iova, granule, granule, true, cookie);
187 }
188 
189 static const struct iommu_flush_ops msm_iommu_flush_ops = {
190 	.tlb_flush_all = __flush_iotlb,
191 	.tlb_flush_walk = __flush_iotlb_walk,
192 	.tlb_flush_leaf = __flush_iotlb_leaf,
193 	.tlb_add_page = __flush_iotlb_page,
194 };
195 
196 static int msm_iommu_alloc_ctx(unsigned long *map, int start, int end)
197 {
198 	int idx;
199 
200 	do {
201 		idx = find_next_zero_bit(map, end, start);
202 		if (idx == end)
203 			return -ENOSPC;
204 	} while (test_and_set_bit(idx, map));
205 
206 	return idx;
207 }
208 
209 static void msm_iommu_free_ctx(unsigned long *map, int idx)
210 {
211 	clear_bit(idx, map);
212 }
213 
214 static void config_mids(struct msm_iommu_dev *iommu,
215 			struct msm_iommu_ctx_dev *master)
216 {
217 	int mid, ctx, i;
218 
219 	for (i = 0; i < master->num_mids; i++) {
220 		mid = master->mids[i];
221 		ctx = master->num;
222 
223 		SET_M2VCBR_N(iommu->base, mid, 0);
224 		SET_CBACR_N(iommu->base, ctx, 0);
225 
226 		/* Set VMID = 0 */
227 		SET_VMID(iommu->base, mid, 0);
228 
229 		/* Set the context number for that MID to this context */
230 		SET_CBNDX(iommu->base, mid, ctx);
231 
232 		/* Set MID associated with this context bank to 0*/
233 		SET_CBVMID(iommu->base, ctx, 0);
234 
235 		/* Set the ASID for TLB tagging for this context */
236 		SET_CONTEXTIDR_ASID(iommu->base, ctx, ctx);
237 
238 		/* Set security bit override to be Non-secure */
239 		SET_NSCFG(iommu->base, mid, 3);
240 	}
241 }
242 
243 static void __reset_context(void __iomem *base, int ctx)
244 {
245 	SET_BPRCOSH(base, ctx, 0);
246 	SET_BPRCISH(base, ctx, 0);
247 	SET_BPRCNSH(base, ctx, 0);
248 	SET_BPSHCFG(base, ctx, 0);
249 	SET_BPMTCFG(base, ctx, 0);
250 	SET_ACTLR(base, ctx, 0);
251 	SET_SCTLR(base, ctx, 0);
252 	SET_FSRRESTORE(base, ctx, 0);
253 	SET_TTBR0(base, ctx, 0);
254 	SET_TTBR1(base, ctx, 0);
255 	SET_TTBCR(base, ctx, 0);
256 	SET_BFBCR(base, ctx, 0);
257 	SET_PAR(base, ctx, 0);
258 	SET_FAR(base, ctx, 0);
259 	SET_CTX_TLBIALL(base, ctx, 0);
260 	SET_TLBFLPTER(base, ctx, 0);
261 	SET_TLBSLPTER(base, ctx, 0);
262 	SET_TLBLKCR(base, ctx, 0);
263 }
264 
265 static void __program_context(void __iomem *base, int ctx,
266 			      struct msm_priv *priv)
267 {
268 	__reset_context(base, ctx);
269 
270 	/* Turn on TEX Remap */
271 	SET_TRE(base, ctx, 1);
272 	SET_AFE(base, ctx, 1);
273 
274 	/* Set up HTW mode */
275 	/* TLB miss configuration: perform HTW on miss */
276 	SET_TLBMCFG(base, ctx, 0x3);
277 
278 	/* V2P configuration: HTW for access */
279 	SET_V2PCFG(base, ctx, 0x3);
280 
281 	SET_TTBCR(base, ctx, priv->cfg.arm_v7s_cfg.tcr);
282 	SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[0]);
283 	SET_TTBR1(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[1]);
284 
285 	/* Set prrr and nmrr */
286 	SET_PRRR(base, ctx, priv->cfg.arm_v7s_cfg.prrr);
287 	SET_NMRR(base, ctx, priv->cfg.arm_v7s_cfg.nmrr);
288 
289 	/* Invalidate the TLB for this context */
290 	SET_CTX_TLBIALL(base, ctx, 0);
291 
292 	/* Set interrupt number to "secure" interrupt */
293 	SET_IRPTNDX(base, ctx, 0);
294 
295 	/* Enable context fault interrupt */
296 	SET_CFEIE(base, ctx, 1);
297 
298 	/* Stall access on a context fault and let the handler deal with it */
299 	SET_CFCFG(base, ctx, 1);
300 
301 	/* Redirect all cacheable requests to L2 slave port. */
302 	SET_RCISH(base, ctx, 1);
303 	SET_RCOSH(base, ctx, 1);
304 	SET_RCNSH(base, ctx, 1);
305 
306 	/* Turn on BFB prefetch */
307 	SET_BFBDFE(base, ctx, 1);
308 
309 	/* Enable the MMU */
310 	SET_M(base, ctx, 1);
311 }
312 
313 static struct iommu_domain *msm_iommu_domain_alloc(unsigned type)
314 {
315 	struct msm_priv *priv;
316 
317 	if (type != IOMMU_DOMAIN_UNMANAGED)
318 		return NULL;
319 
320 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
321 	if (!priv)
322 		goto fail_nomem;
323 
324 	INIT_LIST_HEAD(&priv->list_attached);
325 
326 	priv->domain.geometry.aperture_start = 0;
327 	priv->domain.geometry.aperture_end   = (1ULL << 32) - 1;
328 	priv->domain.geometry.force_aperture = true;
329 
330 	return &priv->domain;
331 
332 fail_nomem:
333 	kfree(priv);
334 	return NULL;
335 }
336 
337 static void msm_iommu_domain_free(struct iommu_domain *domain)
338 {
339 	struct msm_priv *priv;
340 	unsigned long flags;
341 
342 	spin_lock_irqsave(&msm_iommu_lock, flags);
343 	priv = to_msm_priv(domain);
344 	kfree(priv);
345 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
346 }
347 
348 static int msm_iommu_domain_config(struct msm_priv *priv)
349 {
350 	spin_lock_init(&priv->pgtlock);
351 
352 	priv->cfg = (struct io_pgtable_cfg) {
353 		.quirks = IO_PGTABLE_QUIRK_TLBI_ON_MAP,
354 		.pgsize_bitmap = msm_iommu_ops.pgsize_bitmap,
355 		.ias = 32,
356 		.oas = 32,
357 		.tlb = &msm_iommu_flush_ops,
358 		.iommu_dev = priv->dev,
359 	};
360 
361 	priv->iop = alloc_io_pgtable_ops(ARM_V7S, &priv->cfg, priv);
362 	if (!priv->iop) {
363 		dev_err(priv->dev, "Failed to allocate pgtable\n");
364 		return -EINVAL;
365 	}
366 
367 	msm_iommu_ops.pgsize_bitmap = priv->cfg.pgsize_bitmap;
368 
369 	return 0;
370 }
371 
372 /* Must be called under msm_iommu_lock */
373 static struct msm_iommu_dev *find_iommu_for_dev(struct device *dev)
374 {
375 	struct msm_iommu_dev *iommu, *ret = NULL;
376 	struct msm_iommu_ctx_dev *master;
377 
378 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
379 		master = list_first_entry(&iommu->ctx_list,
380 					  struct msm_iommu_ctx_dev,
381 					  list);
382 		if (master->of_node == dev->of_node) {
383 			ret = iommu;
384 			break;
385 		}
386 	}
387 
388 	return ret;
389 }
390 
391 static int msm_iommu_add_device(struct device *dev)
392 {
393 	struct msm_iommu_dev *iommu;
394 	struct iommu_group *group;
395 	unsigned long flags;
396 
397 	spin_lock_irqsave(&msm_iommu_lock, flags);
398 	iommu = find_iommu_for_dev(dev);
399 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
400 
401 	if (iommu)
402 		iommu_device_link(&iommu->iommu, dev);
403 	else
404 		return -ENODEV;
405 
406 	group = iommu_group_get_for_dev(dev);
407 	if (IS_ERR(group))
408 		return PTR_ERR(group);
409 
410 	iommu_group_put(group);
411 
412 	return 0;
413 }
414 
415 static void msm_iommu_remove_device(struct device *dev)
416 {
417 	struct msm_iommu_dev *iommu;
418 	unsigned long flags;
419 
420 	spin_lock_irqsave(&msm_iommu_lock, flags);
421 	iommu = find_iommu_for_dev(dev);
422 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
423 
424 	if (iommu)
425 		iommu_device_unlink(&iommu->iommu, dev);
426 
427 	iommu_group_remove_device(dev);
428 }
429 
430 static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
431 {
432 	int ret = 0;
433 	unsigned long flags;
434 	struct msm_iommu_dev *iommu;
435 	struct msm_priv *priv = to_msm_priv(domain);
436 	struct msm_iommu_ctx_dev *master;
437 
438 	priv->dev = dev;
439 	msm_iommu_domain_config(priv);
440 
441 	spin_lock_irqsave(&msm_iommu_lock, flags);
442 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
443 		master = list_first_entry(&iommu->ctx_list,
444 					  struct msm_iommu_ctx_dev,
445 					  list);
446 		if (master->of_node == dev->of_node) {
447 			ret = __enable_clocks(iommu);
448 			if (ret)
449 				goto fail;
450 
451 			list_for_each_entry(master, &iommu->ctx_list, list) {
452 				if (master->num) {
453 					dev_err(dev, "domain already attached");
454 					ret = -EEXIST;
455 					goto fail;
456 				}
457 				master->num =
458 					msm_iommu_alloc_ctx(iommu->context_map,
459 							    0, iommu->ncb);
460 				if (IS_ERR_VALUE(master->num)) {
461 					ret = -ENODEV;
462 					goto fail;
463 				}
464 				config_mids(iommu, master);
465 				__program_context(iommu->base, master->num,
466 						  priv);
467 			}
468 			__disable_clocks(iommu);
469 			list_add(&iommu->dom_node, &priv->list_attached);
470 		}
471 	}
472 
473 fail:
474 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
475 
476 	return ret;
477 }
478 
479 static void msm_iommu_detach_dev(struct iommu_domain *domain,
480 				 struct device *dev)
481 {
482 	struct msm_priv *priv = to_msm_priv(domain);
483 	unsigned long flags;
484 	struct msm_iommu_dev *iommu;
485 	struct msm_iommu_ctx_dev *master;
486 	int ret;
487 
488 	free_io_pgtable_ops(priv->iop);
489 
490 	spin_lock_irqsave(&msm_iommu_lock, flags);
491 	list_for_each_entry(iommu, &priv->list_attached, dom_node) {
492 		ret = __enable_clocks(iommu);
493 		if (ret)
494 			goto fail;
495 
496 		list_for_each_entry(master, &iommu->ctx_list, list) {
497 			msm_iommu_free_ctx(iommu->context_map, master->num);
498 			__reset_context(iommu->base, master->num);
499 		}
500 		__disable_clocks(iommu);
501 	}
502 fail:
503 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
504 }
505 
506 static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
507 			 phys_addr_t pa, size_t len, int prot)
508 {
509 	struct msm_priv *priv = to_msm_priv(domain);
510 	unsigned long flags;
511 	int ret;
512 
513 	spin_lock_irqsave(&priv->pgtlock, flags);
514 	ret = priv->iop->map(priv->iop, iova, pa, len, prot);
515 	spin_unlock_irqrestore(&priv->pgtlock, flags);
516 
517 	return ret;
518 }
519 
520 static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
521 			      size_t len, struct iommu_iotlb_gather *gather)
522 {
523 	struct msm_priv *priv = to_msm_priv(domain);
524 	unsigned long flags;
525 
526 	spin_lock_irqsave(&priv->pgtlock, flags);
527 	len = priv->iop->unmap(priv->iop, iova, len, gather);
528 	spin_unlock_irqrestore(&priv->pgtlock, flags);
529 
530 	return len;
531 }
532 
533 static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
534 					  dma_addr_t va)
535 {
536 	struct msm_priv *priv;
537 	struct msm_iommu_dev *iommu;
538 	struct msm_iommu_ctx_dev *master;
539 	unsigned int par;
540 	unsigned long flags;
541 	phys_addr_t ret = 0;
542 
543 	spin_lock_irqsave(&msm_iommu_lock, flags);
544 
545 	priv = to_msm_priv(domain);
546 	iommu = list_first_entry(&priv->list_attached,
547 				 struct msm_iommu_dev, dom_node);
548 
549 	if (list_empty(&iommu->ctx_list))
550 		goto fail;
551 
552 	master = list_first_entry(&iommu->ctx_list,
553 				  struct msm_iommu_ctx_dev, list);
554 	if (!master)
555 		goto fail;
556 
557 	ret = __enable_clocks(iommu);
558 	if (ret)
559 		goto fail;
560 
561 	/* Invalidate context TLB */
562 	SET_CTX_TLBIALL(iommu->base, master->num, 0);
563 	SET_V2PPR(iommu->base, master->num, va & V2Pxx_VA);
564 
565 	par = GET_PAR(iommu->base, master->num);
566 
567 	/* We are dealing with a supersection */
568 	if (GET_NOFAULT_SS(iommu->base, master->num))
569 		ret = (par & 0xFF000000) | (va & 0x00FFFFFF);
570 	else	/* Upper 20 bits from PAR, lower 12 from VA */
571 		ret = (par & 0xFFFFF000) | (va & 0x00000FFF);
572 
573 	if (GET_FAULT(iommu->base, master->num))
574 		ret = 0;
575 
576 	__disable_clocks(iommu);
577 fail:
578 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
579 	return ret;
580 }
581 
582 static bool msm_iommu_capable(enum iommu_cap cap)
583 {
584 	return false;
585 }
586 
587 static void print_ctx_regs(void __iomem *base, int ctx)
588 {
589 	unsigned int fsr = GET_FSR(base, ctx);
590 	pr_err("FAR    = %08x    PAR    = %08x\n",
591 	       GET_FAR(base, ctx), GET_PAR(base, ctx));
592 	pr_err("FSR    = %08x [%s%s%s%s%s%s%s%s%s%s]\n", fsr,
593 			(fsr & 0x02) ? "TF " : "",
594 			(fsr & 0x04) ? "AFF " : "",
595 			(fsr & 0x08) ? "APF " : "",
596 			(fsr & 0x10) ? "TLBMF " : "",
597 			(fsr & 0x20) ? "HTWDEEF " : "",
598 			(fsr & 0x40) ? "HTWSEEF " : "",
599 			(fsr & 0x80) ? "MHF " : "",
600 			(fsr & 0x10000) ? "SL " : "",
601 			(fsr & 0x40000000) ? "SS " : "",
602 			(fsr & 0x80000000) ? "MULTI " : "");
603 
604 	pr_err("FSYNR0 = %08x    FSYNR1 = %08x\n",
605 	       GET_FSYNR0(base, ctx), GET_FSYNR1(base, ctx));
606 	pr_err("TTBR0  = %08x    TTBR1  = %08x\n",
607 	       GET_TTBR0(base, ctx), GET_TTBR1(base, ctx));
608 	pr_err("SCTLR  = %08x    ACTLR  = %08x\n",
609 	       GET_SCTLR(base, ctx), GET_ACTLR(base, ctx));
610 }
611 
612 static void insert_iommu_master(struct device *dev,
613 				struct msm_iommu_dev **iommu,
614 				struct of_phandle_args *spec)
615 {
616 	struct msm_iommu_ctx_dev *master = dev->archdata.iommu;
617 	int sid;
618 
619 	if (list_empty(&(*iommu)->ctx_list)) {
620 		master = kzalloc(sizeof(*master), GFP_ATOMIC);
621 		master->of_node = dev->of_node;
622 		list_add(&master->list, &(*iommu)->ctx_list);
623 		dev->archdata.iommu = master;
624 	}
625 
626 	for (sid = 0; sid < master->num_mids; sid++)
627 		if (master->mids[sid] == spec->args[0]) {
628 			dev_warn(dev, "Stream ID 0x%hx repeated; ignoring\n",
629 				 sid);
630 			return;
631 		}
632 
633 	master->mids[master->num_mids++] = spec->args[0];
634 }
635 
636 static int qcom_iommu_of_xlate(struct device *dev,
637 			       struct of_phandle_args *spec)
638 {
639 	struct msm_iommu_dev *iommu;
640 	unsigned long flags;
641 	int ret = 0;
642 
643 	spin_lock_irqsave(&msm_iommu_lock, flags);
644 	list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
645 		if (iommu->dev->of_node == spec->np)
646 			break;
647 
648 	if (!iommu || iommu->dev->of_node != spec->np) {
649 		ret = -ENODEV;
650 		goto fail;
651 	}
652 
653 	insert_iommu_master(dev, &iommu, spec);
654 fail:
655 	spin_unlock_irqrestore(&msm_iommu_lock, flags);
656 
657 	return ret;
658 }
659 
660 irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
661 {
662 	struct msm_iommu_dev *iommu = dev_id;
663 	unsigned int fsr;
664 	int i, ret;
665 
666 	spin_lock(&msm_iommu_lock);
667 
668 	if (!iommu) {
669 		pr_err("Invalid device ID in context interrupt handler\n");
670 		goto fail;
671 	}
672 
673 	pr_err("Unexpected IOMMU page fault!\n");
674 	pr_err("base = %08x\n", (unsigned int)iommu->base);
675 
676 	ret = __enable_clocks(iommu);
677 	if (ret)
678 		goto fail;
679 
680 	for (i = 0; i < iommu->ncb; i++) {
681 		fsr = GET_FSR(iommu->base, i);
682 		if (fsr) {
683 			pr_err("Fault occurred in context %d.\n", i);
684 			pr_err("Interesting registers:\n");
685 			print_ctx_regs(iommu->base, i);
686 			SET_FSR(iommu->base, i, 0x4000000F);
687 		}
688 	}
689 	__disable_clocks(iommu);
690 fail:
691 	spin_unlock(&msm_iommu_lock);
692 	return 0;
693 }
694 
695 static struct iommu_ops msm_iommu_ops = {
696 	.capable = msm_iommu_capable,
697 	.domain_alloc = msm_iommu_domain_alloc,
698 	.domain_free = msm_iommu_domain_free,
699 	.attach_dev = msm_iommu_attach_dev,
700 	.detach_dev = msm_iommu_detach_dev,
701 	.map = msm_iommu_map,
702 	.unmap = msm_iommu_unmap,
703 	/*
704 	 * Nothing is needed here, the barrier to guarantee
705 	 * completion of the tlb sync operation is implicitly
706 	 * taken care when the iommu client does a writel before
707 	 * kick starting the other master.
708 	 */
709 	.iotlb_sync = NULL,
710 	.iova_to_phys = msm_iommu_iova_to_phys,
711 	.add_device = msm_iommu_add_device,
712 	.remove_device = msm_iommu_remove_device,
713 	.device_group = generic_device_group,
714 	.pgsize_bitmap = MSM_IOMMU_PGSIZES,
715 	.of_xlate = qcom_iommu_of_xlate,
716 };
717 
718 static int msm_iommu_probe(struct platform_device *pdev)
719 {
720 	struct resource *r;
721 	resource_size_t ioaddr;
722 	struct msm_iommu_dev *iommu;
723 	int ret, par, val;
724 
725 	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
726 	if (!iommu)
727 		return -ENODEV;
728 
729 	iommu->dev = &pdev->dev;
730 	INIT_LIST_HEAD(&iommu->ctx_list);
731 
732 	iommu->pclk = devm_clk_get(iommu->dev, "smmu_pclk");
733 	if (IS_ERR(iommu->pclk)) {
734 		dev_err(iommu->dev, "could not get smmu_pclk\n");
735 		return PTR_ERR(iommu->pclk);
736 	}
737 
738 	ret = clk_prepare(iommu->pclk);
739 	if (ret) {
740 		dev_err(iommu->dev, "could not prepare smmu_pclk\n");
741 		return ret;
742 	}
743 
744 	iommu->clk = devm_clk_get(iommu->dev, "iommu_clk");
745 	if (IS_ERR(iommu->clk)) {
746 		dev_err(iommu->dev, "could not get iommu_clk\n");
747 		clk_unprepare(iommu->pclk);
748 		return PTR_ERR(iommu->clk);
749 	}
750 
751 	ret = clk_prepare(iommu->clk);
752 	if (ret) {
753 		dev_err(iommu->dev, "could not prepare iommu_clk\n");
754 		clk_unprepare(iommu->pclk);
755 		return ret;
756 	}
757 
758 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
759 	iommu->base = devm_ioremap_resource(iommu->dev, r);
760 	if (IS_ERR(iommu->base)) {
761 		dev_err(iommu->dev, "could not get iommu base\n");
762 		ret = PTR_ERR(iommu->base);
763 		goto fail;
764 	}
765 	ioaddr = r->start;
766 
767 	iommu->irq = platform_get_irq(pdev, 0);
768 	if (iommu->irq < 0) {
769 		ret = -ENODEV;
770 		goto fail;
771 	}
772 
773 	ret = of_property_read_u32(iommu->dev->of_node, "qcom,ncb", &val);
774 	if (ret) {
775 		dev_err(iommu->dev, "could not get ncb\n");
776 		goto fail;
777 	}
778 	iommu->ncb = val;
779 
780 	msm_iommu_reset(iommu->base, iommu->ncb);
781 	SET_M(iommu->base, 0, 1);
782 	SET_PAR(iommu->base, 0, 0);
783 	SET_V2PCFG(iommu->base, 0, 1);
784 	SET_V2PPR(iommu->base, 0, 0);
785 	par = GET_PAR(iommu->base, 0);
786 	SET_V2PCFG(iommu->base, 0, 0);
787 	SET_M(iommu->base, 0, 0);
788 
789 	if (!par) {
790 		pr_err("Invalid PAR value detected\n");
791 		ret = -ENODEV;
792 		goto fail;
793 	}
794 
795 	ret = devm_request_threaded_irq(iommu->dev, iommu->irq, NULL,
796 					msm_iommu_fault_handler,
797 					IRQF_ONESHOT | IRQF_SHARED,
798 					"msm_iommu_secure_irpt_handler",
799 					iommu);
800 	if (ret) {
801 		pr_err("Request IRQ %d failed with ret=%d\n", iommu->irq, ret);
802 		goto fail;
803 	}
804 
805 	list_add(&iommu->dev_node, &qcom_iommu_devices);
806 
807 	ret = iommu_device_sysfs_add(&iommu->iommu, iommu->dev, NULL,
808 				     "msm-smmu.%pa", &ioaddr);
809 	if (ret) {
810 		pr_err("Could not add msm-smmu at %pa to sysfs\n", &ioaddr);
811 		goto fail;
812 	}
813 
814 	iommu_device_set_ops(&iommu->iommu, &msm_iommu_ops);
815 	iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
816 
817 	ret = iommu_device_register(&iommu->iommu);
818 	if (ret) {
819 		pr_err("Could not register msm-smmu at %pa\n", &ioaddr);
820 		goto fail;
821 	}
822 
823 	bus_set_iommu(&platform_bus_type, &msm_iommu_ops);
824 
825 	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
826 		iommu->base, iommu->irq, iommu->ncb);
827 
828 	return ret;
829 fail:
830 	clk_unprepare(iommu->clk);
831 	clk_unprepare(iommu->pclk);
832 	return ret;
833 }
834 
835 static const struct of_device_id msm_iommu_dt_match[] = {
836 	{ .compatible = "qcom,apq8064-iommu" },
837 	{}
838 };
839 
840 static int msm_iommu_remove(struct platform_device *pdev)
841 {
842 	struct msm_iommu_dev *iommu = platform_get_drvdata(pdev);
843 
844 	clk_unprepare(iommu->clk);
845 	clk_unprepare(iommu->pclk);
846 	return 0;
847 }
848 
849 static struct platform_driver msm_iommu_driver = {
850 	.driver = {
851 		.name	= "msm_iommu",
852 		.of_match_table = msm_iommu_dt_match,
853 	},
854 	.probe		= msm_iommu_probe,
855 	.remove		= msm_iommu_remove,
856 };
857 
858 static int __init msm_iommu_driver_init(void)
859 {
860 	int ret;
861 
862 	ret = platform_driver_register(&msm_iommu_driver);
863 	if (ret != 0)
864 		pr_err("Failed to register IOMMU driver\n");
865 
866 	return ret;
867 }
868 subsys_initcall(msm_iommu_driver_init);
869 
870