1 // SPDX-License-Identifier:	GPL-2.0
2 /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
3 #include <linux/atomic.h>
4 #include <linux/bitfield.h>
5 #include <linux/delay.h>
6 #include <linux/dma-mapping.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/iopoll.h>
10 #include <linux/io-pgtable.h>
11 #include <linux/iommu.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/shmem_fs.h>
15 #include <linux/sizes.h>
16 
17 #include "panfrost_device.h"
18 #include "panfrost_mmu.h"
19 #include "panfrost_gem.h"
20 #include "panfrost_features.h"
21 #include "panfrost_regs.h"
22 
23 #define mmu_write(dev, reg, data) writel(data, dev->iomem + reg)
24 #define mmu_read(dev, reg) readl(dev->iomem + reg)
25 
26 static int wait_ready(struct panfrost_device *pfdev, u32 as_nr)
27 {
28 	int ret;
29 	u32 val;
30 
31 	/* Wait for the MMU status to indicate there is no active command, in
32 	 * case one is pending. */
33 	ret = readl_relaxed_poll_timeout_atomic(pfdev->iomem + AS_STATUS(as_nr),
34 		val, !(val & AS_STATUS_AS_ACTIVE), 10, 1000);
35 
36 	if (ret)
37 		dev_err(pfdev->dev, "AS_ACTIVE bit stuck\n");
38 
39 	return ret;
40 }
41 
42 static int write_cmd(struct panfrost_device *pfdev, u32 as_nr, u32 cmd)
43 {
44 	int status;
45 
46 	/* write AS_COMMAND when MMU is ready to accept another command */
47 	status = wait_ready(pfdev, as_nr);
48 	if (!status)
49 		mmu_write(pfdev, AS_COMMAND(as_nr), cmd);
50 
51 	return status;
52 }
53 
54 static void lock_region(struct panfrost_device *pfdev, u32 as_nr,
55 			u64 iova, size_t size)
56 {
57 	u8 region_width;
58 	u64 region = iova & PAGE_MASK;
59 	/*
60 	 * fls returns:
61 	 * 1 .. 32
62 	 *
63 	 * 10 + fls(num_pages)
64 	 * results in the range (11 .. 42)
65 	 */
66 
67 	size = round_up(size, PAGE_SIZE);
68 
69 	region_width = 10 + fls(size >> PAGE_SHIFT);
70 	if ((size >> PAGE_SHIFT) != (1ul << (region_width - 11))) {
71 		/* not pow2, so must go up to the next pow2 */
72 		region_width += 1;
73 	}
74 	region |= region_width;
75 
76 	/* Lock the region that needs to be updated */
77 	mmu_write(pfdev, AS_LOCKADDR_LO(as_nr), region & 0xFFFFFFFFUL);
78 	mmu_write(pfdev, AS_LOCKADDR_HI(as_nr), (region >> 32) & 0xFFFFFFFFUL);
79 	write_cmd(pfdev, as_nr, AS_COMMAND_LOCK);
80 }
81 
82 
83 static int mmu_hw_do_operation(struct panfrost_device *pfdev,
84 			       struct panfrost_mmu *mmu,
85 			       u64 iova, size_t size, u32 op)
86 {
87 	int ret, as_nr;
88 
89 	spin_lock(&pfdev->as_lock);
90 	as_nr = mmu->as;
91 
92 	if (as_nr < 0) {
93 		spin_unlock(&pfdev->as_lock);
94 		return 0;
95 	}
96 
97 	if (op != AS_COMMAND_UNLOCK)
98 		lock_region(pfdev, as_nr, iova, size);
99 
100 	/* Run the MMU operation */
101 	write_cmd(pfdev, as_nr, op);
102 
103 	/* Wait for the flush to complete */
104 	ret = wait_ready(pfdev, as_nr);
105 
106 	spin_unlock(&pfdev->as_lock);
107 
108 	return ret;
109 }
110 
111 static void panfrost_mmu_enable(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
112 {
113 	int as_nr = mmu->as;
114 	struct io_pgtable_cfg *cfg = &mmu->pgtbl_cfg;
115 	u64 transtab = cfg->arm_mali_lpae_cfg.transtab;
116 	u64 memattr = cfg->arm_mali_lpae_cfg.memattr;
117 
118 	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), transtab & 0xffffffffUL);
119 	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), transtab >> 32);
120 
121 	/* Need to revisit mem attrs.
122 	 * NC is the default, Mali driver is inner WT.
123 	 */
124 	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), memattr & 0xffffffffUL);
125 	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), memattr >> 32);
126 
127 	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
128 }
129 
130 static void mmu_disable(struct panfrost_device *pfdev, u32 as_nr)
131 {
132 	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), 0);
133 	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), 0);
134 
135 	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), 0);
136 	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), 0);
137 
138 	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
139 }
140 
141 u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
142 {
143 	int as;
144 
145 	spin_lock(&pfdev->as_lock);
146 
147 	as = mmu->as;
148 	if (as >= 0) {
149 		int en = atomic_inc_return(&mmu->as_count);
150 		WARN_ON(en >= NUM_JOB_SLOTS);
151 
152 		list_move(&mmu->list, &pfdev->as_lru_list);
153 		goto out;
154 	}
155 
156 	/* Check for a free AS */
157 	as = ffz(pfdev->as_alloc_mask);
158 	if (!(BIT(as) & pfdev->features.as_present)) {
159 		struct panfrost_mmu *lru_mmu;
160 
161 		list_for_each_entry_reverse(lru_mmu, &pfdev->as_lru_list, list) {
162 			if (!atomic_read(&lru_mmu->as_count))
163 				break;
164 		}
165 		WARN_ON(&lru_mmu->list == &pfdev->as_lru_list);
166 
167 		list_del_init(&lru_mmu->list);
168 		as = lru_mmu->as;
169 
170 		WARN_ON(as < 0);
171 		lru_mmu->as = -1;
172 	}
173 
174 	/* Assign the free or reclaimed AS to the FD */
175 	mmu->as = as;
176 	set_bit(as, &pfdev->as_alloc_mask);
177 	atomic_set(&mmu->as_count, 1);
178 	list_add(&mmu->list, &pfdev->as_lru_list);
179 
180 	dev_dbg(pfdev->dev, "Assigned AS%d to mmu %p, alloc_mask=%lx", as, mmu, pfdev->as_alloc_mask);
181 
182 	panfrost_mmu_enable(pfdev, mmu);
183 
184 out:
185 	spin_unlock(&pfdev->as_lock);
186 	return as;
187 }
188 
189 void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
190 {
191 	atomic_dec(&mmu->as_count);
192 	WARN_ON(atomic_read(&mmu->as_count) < 0);
193 }
194 
195 void panfrost_mmu_reset(struct panfrost_device *pfdev)
196 {
197 	struct panfrost_mmu *mmu, *mmu_tmp;
198 
199 	spin_lock(&pfdev->as_lock);
200 
201 	pfdev->as_alloc_mask = 0;
202 
203 	list_for_each_entry_safe(mmu, mmu_tmp, &pfdev->as_lru_list, list) {
204 		mmu->as = -1;
205 		atomic_set(&mmu->as_count, 0);
206 		list_del_init(&mmu->list);
207 	}
208 
209 	spin_unlock(&pfdev->as_lock);
210 
211 	mmu_write(pfdev, MMU_INT_CLEAR, ~0);
212 	mmu_write(pfdev, MMU_INT_MASK, ~0);
213 }
214 
215 static size_t get_pgsize(u64 addr, size_t size)
216 {
217 	if (addr & (SZ_2M - 1) || size < SZ_2M)
218 		return SZ_4K;
219 
220 	return SZ_2M;
221 }
222 
223 static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
224 		      u64 iova, int prot, struct sg_table *sgt)
225 {
226 	unsigned int count;
227 	struct scatterlist *sgl;
228 	struct io_pgtable_ops *ops = mmu->pgtbl_ops;
229 	u64 start_iova = iova;
230 
231 	mutex_lock(&mmu->lock);
232 
233 	for_each_sg(sgt->sgl, sgl, sgt->nents, count) {
234 		unsigned long paddr = sg_dma_address(sgl);
235 		size_t len = sg_dma_len(sgl);
236 
237 		dev_dbg(pfdev->dev, "map: as=%d, iova=%llx, paddr=%lx, len=%zx", mmu->as, iova, paddr, len);
238 
239 		while (len) {
240 			size_t pgsize = get_pgsize(iova | paddr, len);
241 
242 			ops->map(ops, iova, paddr, pgsize, prot);
243 			iova += pgsize;
244 			paddr += pgsize;
245 			len -= pgsize;
246 		}
247 	}
248 
249 	mmu_hw_do_operation(pfdev, mmu, start_iova, iova - start_iova,
250 			    AS_COMMAND_FLUSH_PT);
251 
252 	mutex_unlock(&mmu->lock);
253 
254 	return 0;
255 }
256 
257 int panfrost_mmu_map(struct panfrost_gem_object *bo)
258 {
259 	struct drm_gem_object *obj = &bo->base.base;
260 	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
261 	struct sg_table *sgt;
262 	int ret;
263 	int prot = IOMMU_READ | IOMMU_WRITE;
264 
265 	if (WARN_ON(bo->is_mapped))
266 		return 0;
267 
268 	if (bo->noexec)
269 		prot |= IOMMU_NOEXEC;
270 
271 	sgt = drm_gem_shmem_get_pages_sgt(obj);
272 	if (WARN_ON(IS_ERR(sgt)))
273 		return PTR_ERR(sgt);
274 
275 	ret = pm_runtime_get_sync(pfdev->dev);
276 	if (ret < 0)
277 		return ret;
278 
279 	mmu_map_sg(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT, prot, sgt);
280 
281 	pm_runtime_mark_last_busy(pfdev->dev);
282 	pm_runtime_put_autosuspend(pfdev->dev);
283 	bo->is_mapped = true;
284 
285 	return 0;
286 }
287 
288 void panfrost_mmu_unmap(struct panfrost_gem_object *bo)
289 {
290 	struct drm_gem_object *obj = &bo->base.base;
291 	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
292 	struct io_pgtable_ops *ops = bo->mmu->pgtbl_ops;
293 	u64 iova = bo->node.start << PAGE_SHIFT;
294 	size_t len = bo->node.size << PAGE_SHIFT;
295 	size_t unmapped_len = 0;
296 	int ret;
297 
298 	if (WARN_ON(!bo->is_mapped))
299 		return;
300 
301 	dev_dbg(pfdev->dev, "unmap: as=%d, iova=%llx, len=%zx", bo->mmu->as, iova, len);
302 
303 	ret = pm_runtime_get_sync(pfdev->dev);
304 	if (ret < 0)
305 		return;
306 
307 	mutex_lock(&bo->mmu->lock);
308 
309 	while (unmapped_len < len) {
310 		size_t unmapped_page;
311 		size_t pgsize = get_pgsize(iova, len - unmapped_len);
312 
313 		if (ops->iova_to_phys(ops, iova)) {
314 			unmapped_page = ops->unmap(ops, iova, pgsize);
315 			WARN_ON(unmapped_page != pgsize);
316 		}
317 		iova += pgsize;
318 		unmapped_len += pgsize;
319 	}
320 
321 	mmu_hw_do_operation(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT,
322 			    bo->node.size << PAGE_SHIFT, AS_COMMAND_FLUSH_PT);
323 
324 	mutex_unlock(&bo->mmu->lock);
325 
326 	pm_runtime_mark_last_busy(pfdev->dev);
327 	pm_runtime_put_autosuspend(pfdev->dev);
328 	bo->is_mapped = false;
329 }
330 
331 static void mmu_tlb_inv_context_s1(void *cookie)
332 {
333 	struct panfrost_file_priv *priv = cookie;
334 
335 	mmu_hw_do_operation(priv->pfdev, &priv->mmu, 0, ~0UL, AS_COMMAND_FLUSH_MEM);
336 }
337 
338 static void mmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
339 				     size_t granule, bool leaf, void *cookie)
340 {}
341 
342 static void mmu_tlb_sync_context(void *cookie)
343 {
344 	//struct panfrost_device *pfdev = cookie;
345 	// TODO: Wait 1000 GPU cycles for HW_ISSUE_6367/T60X
346 }
347 
348 static const struct iommu_gather_ops mmu_tlb_ops = {
349 	.tlb_flush_all	= mmu_tlb_inv_context_s1,
350 	.tlb_add_flush	= mmu_tlb_inv_range_nosync,
351 	.tlb_sync	= mmu_tlb_sync_context,
352 };
353 
354 int panfrost_mmu_pgtable_alloc(struct panfrost_file_priv *priv)
355 {
356 	struct panfrost_mmu *mmu = &priv->mmu;
357 	struct panfrost_device *pfdev = priv->pfdev;
358 
359 	mutex_init(&mmu->lock);
360 	INIT_LIST_HEAD(&mmu->list);
361 	mmu->as = -1;
362 
363 	mmu->pgtbl_cfg = (struct io_pgtable_cfg) {
364 		.pgsize_bitmap	= SZ_4K | SZ_2M,
365 		.ias		= FIELD_GET(0xff, pfdev->features.mmu_features),
366 		.oas		= FIELD_GET(0xff00, pfdev->features.mmu_features),
367 		.tlb		= &mmu_tlb_ops,
368 		.iommu_dev	= pfdev->dev,
369 	};
370 
371 	mmu->pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &mmu->pgtbl_cfg,
372 					      priv);
373 	if (!mmu->pgtbl_ops)
374 		return -EINVAL;
375 
376 	return 0;
377 }
378 
379 void panfrost_mmu_pgtable_free(struct panfrost_file_priv *priv)
380 {
381 	struct panfrost_device *pfdev = priv->pfdev;
382 	struct panfrost_mmu *mmu = &priv->mmu;
383 
384 	spin_lock(&pfdev->as_lock);
385 	if (mmu->as >= 0) {
386 		clear_bit(mmu->as, &pfdev->as_alloc_mask);
387 		clear_bit(mmu->as, &pfdev->as_in_use_mask);
388 		list_del(&mmu->list);
389 	}
390 	spin_unlock(&pfdev->as_lock);
391 
392 	free_io_pgtable_ops(mmu->pgtbl_ops);
393 }
394 
395 static struct drm_mm_node *addr_to_drm_mm_node(struct panfrost_device *pfdev, int as, u64 addr)
396 {
397 	struct drm_mm_node *node = NULL;
398 	u64 offset = addr >> PAGE_SHIFT;
399 	struct panfrost_mmu *mmu;
400 
401 	spin_lock(&pfdev->as_lock);
402 	list_for_each_entry(mmu, &pfdev->as_lru_list, list) {
403 		struct panfrost_file_priv *priv;
404 		if (as != mmu->as)
405 			continue;
406 
407 		priv = container_of(mmu, struct panfrost_file_priv, mmu);
408 		drm_mm_for_each_node(node, &priv->mm) {
409 			if (offset >= node->start && offset < (node->start + node->size))
410 				goto out;
411 		}
412 	}
413 
414 out:
415 	spin_unlock(&pfdev->as_lock);
416 	return node;
417 }
418 
419 #define NUM_FAULT_PAGES (SZ_2M / PAGE_SIZE)
420 
421 int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, u64 addr)
422 {
423 	int ret, i;
424 	struct drm_mm_node *node;
425 	struct panfrost_gem_object *bo;
426 	struct address_space *mapping;
427 	pgoff_t page_offset;
428 	struct sg_table *sgt;
429 	struct page **pages;
430 
431 	node = addr_to_drm_mm_node(pfdev, as, addr);
432 	if (!node)
433 		return -ENOENT;
434 
435 	bo = drm_mm_node_to_panfrost_bo(node);
436 	if (!bo->is_heap) {
437 		dev_WARN(pfdev->dev, "matching BO is not heap type (GPU VA = %llx)",
438 			 node->start << PAGE_SHIFT);
439 		return -EINVAL;
440 	}
441 	WARN_ON(bo->mmu->as != as);
442 
443 	/* Assume 2MB alignment and size multiple */
444 	addr &= ~((u64)SZ_2M - 1);
445 	page_offset = addr >> PAGE_SHIFT;
446 	page_offset -= node->start;
447 
448 	mutex_lock(&bo->base.pages_lock);
449 
450 	if (!bo->base.pages) {
451 		bo->sgts = kvmalloc_array(bo->base.base.size / SZ_2M,
452 				     sizeof(struct sg_table), GFP_KERNEL | __GFP_ZERO);
453 		if (!bo->sgts) {
454 			mutex_unlock(&bo->base.pages_lock);
455 			return -ENOMEM;
456 		}
457 
458 		pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
459 				       sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
460 		if (!pages) {
461 			kfree(bo->sgts);
462 			bo->sgts = NULL;
463 			mutex_unlock(&bo->base.pages_lock);
464 			return -ENOMEM;
465 		}
466 		bo->base.pages = pages;
467 		bo->base.pages_use_count = 1;
468 	} else
469 		pages = bo->base.pages;
470 
471 	mapping = bo->base.base.filp->f_mapping;
472 	mapping_set_unevictable(mapping);
473 
474 	for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
475 		pages[i] = shmem_read_mapping_page(mapping, i);
476 		if (IS_ERR(pages[i])) {
477 			mutex_unlock(&bo->base.pages_lock);
478 			ret = PTR_ERR(pages[i]);
479 			goto err_pages;
480 		}
481 	}
482 
483 	mutex_unlock(&bo->base.pages_lock);
484 
485 	sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
486 	ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
487 					NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL);
488 	if (ret)
489 		goto err_pages;
490 
491 	if (!dma_map_sg(pfdev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL)) {
492 		ret = -EINVAL;
493 		goto err_map;
494 	}
495 
496 	mmu_map_sg(pfdev, bo->mmu, addr, IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
497 
498 	bo->is_mapped = true;
499 
500 	dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
501 
502 	return 0;
503 
504 err_map:
505 	sg_free_table(sgt);
506 err_pages:
507 	drm_gem_shmem_put_pages(&bo->base);
508 	return ret;
509 }
510 
511 static const char *access_type_name(struct panfrost_device *pfdev,
512 		u32 fault_status)
513 {
514 	switch (fault_status & AS_FAULTSTATUS_ACCESS_TYPE_MASK) {
515 	case AS_FAULTSTATUS_ACCESS_TYPE_ATOMIC:
516 		if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU))
517 			return "ATOMIC";
518 		else
519 			return "UNKNOWN";
520 	case AS_FAULTSTATUS_ACCESS_TYPE_READ:
521 		return "READ";
522 	case AS_FAULTSTATUS_ACCESS_TYPE_WRITE:
523 		return "WRITE";
524 	case AS_FAULTSTATUS_ACCESS_TYPE_EX:
525 		return "EXECUTE";
526 	default:
527 		WARN_ON(1);
528 		return NULL;
529 	}
530 }
531 
532 static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data)
533 {
534 	struct panfrost_device *pfdev = data;
535 
536 	if (!mmu_read(pfdev, MMU_INT_STAT))
537 		return IRQ_NONE;
538 
539 	mmu_write(pfdev, MMU_INT_MASK, 0);
540 	return IRQ_WAKE_THREAD;
541 }
542 
543 static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
544 {
545 	struct panfrost_device *pfdev = data;
546 	u32 status = mmu_read(pfdev, MMU_INT_RAWSTAT);
547 	int i, ret;
548 
549 	for (i = 0; status; i++) {
550 		u32 mask = BIT(i) | BIT(i + 16);
551 		u64 addr;
552 		u32 fault_status;
553 		u32 exception_type;
554 		u32 access_type;
555 		u32 source_id;
556 
557 		if (!(status & mask))
558 			continue;
559 
560 		fault_status = mmu_read(pfdev, AS_FAULTSTATUS(i));
561 		addr = mmu_read(pfdev, AS_FAULTADDRESS_LO(i));
562 		addr |= (u64)mmu_read(pfdev, AS_FAULTADDRESS_HI(i)) << 32;
563 
564 		/* decode the fault status */
565 		exception_type = fault_status & 0xFF;
566 		access_type = (fault_status >> 8) & 0x3;
567 		source_id = (fault_status >> 16);
568 
569 		/* Page fault only */
570 		if ((status & mask) == BIT(i)) {
571 			WARN_ON(exception_type < 0xC1 || exception_type > 0xC4);
572 
573 			ret = panfrost_mmu_map_fault_addr(pfdev, i, addr);
574 			if (!ret) {
575 				mmu_write(pfdev, MMU_INT_CLEAR, BIT(i));
576 				status &= ~mask;
577 				continue;
578 			}
579 		}
580 
581 		/* terminal fault, print info about the fault */
582 		dev_err(pfdev->dev,
583 			"Unhandled Page fault in AS%d at VA 0x%016llX\n"
584 			"Reason: %s\n"
585 			"raw fault status: 0x%X\n"
586 			"decoded fault status: %s\n"
587 			"exception type 0x%X: %s\n"
588 			"access type 0x%X: %s\n"
589 			"source id 0x%X\n",
590 			i, addr,
591 			"TODO",
592 			fault_status,
593 			(fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE FAULT"),
594 			exception_type, panfrost_exception_name(pfdev, exception_type),
595 			access_type, access_type_name(pfdev, fault_status),
596 			source_id);
597 
598 		mmu_write(pfdev, MMU_INT_CLEAR, mask);
599 
600 		status &= ~mask;
601 	}
602 
603 	mmu_write(pfdev, MMU_INT_MASK, ~0);
604 	return IRQ_HANDLED;
605 };
606 
607 int panfrost_mmu_init(struct panfrost_device *pfdev)
608 {
609 	int err, irq;
610 
611 	irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "mmu");
612 	if (irq <= 0)
613 		return -ENODEV;
614 
615 	err = devm_request_threaded_irq(pfdev->dev, irq, panfrost_mmu_irq_handler,
616 					panfrost_mmu_irq_handler_thread,
617 					IRQF_SHARED, "mmu", pfdev);
618 
619 	if (err) {
620 		dev_err(pfdev->dev, "failed to request mmu irq");
621 		return err;
622 	}
623 
624 	return 0;
625 }
626 
627 void panfrost_mmu_fini(struct panfrost_device *pfdev)
628 {
629 	mmu_write(pfdev, MMU_INT_MASK, 0);
630 	mmu_disable(pfdev, 0);
631 }
632