1// SPDX-License-Identifier: GPL-2.0
2/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
3
4#include <drm/panfrost_drm.h>
5
6#include <linux/atomic.h>
7#include <linux/bitfield.h>
8#include <linux/delay.h>
9#include <linux/dma-mapping.h>
10#include <linux/interrupt.h>
11#include <linux/io.h>
12#include <linux/iopoll.h>
13#include <linux/io-pgtable.h>
14#include <linux/iommu.h>
15#include <linux/platform_device.h>
16#include <linux/pm_runtime.h>
17#include <linux/shmem_fs.h>
18#include <linux/sizes.h>
19
20#include "panfrost_device.h"
21#include "panfrost_mmu.h"
22#include "panfrost_gem.h"
23#include "panfrost_features.h"
24#include "panfrost_regs.h"
25
26#define mmu_write(dev, reg, data) writel(data, dev->iomem + reg)
27#define mmu_read(dev, reg) readl(dev->iomem + reg)
28
29static int wait_ready(struct panfrost_device *pfdev, u32 as_nr)
30{
31	int ret;
32	u32 val;
33
34	/* Wait for the MMU status to indicate there is no active command, in
35	 * case one is pending. */
36	ret = readl_relaxed_poll_timeout_atomic(pfdev->iomem + AS_STATUS(as_nr),
37		val, !(val & AS_STATUS_AS_ACTIVE), 10, 100000);
38
39	if (ret) {
40		/* The GPU hung, let's trigger a reset */
41		panfrost_device_schedule_reset(pfdev);
42		dev_err(pfdev->dev, "AS_ACTIVE bit stuck\n");
43	}
44
45	return ret;
46}
47
48static int write_cmd(struct panfrost_device *pfdev, u32 as_nr, u32 cmd)
49{
50	int status;
51
52	/* write AS_COMMAND when MMU is ready to accept another command */
53	status = wait_ready(pfdev, as_nr);
54	if (!status)
55		mmu_write(pfdev, AS_COMMAND(as_nr), cmd);
56
57	return status;
58}
59
60static void lock_region(struct panfrost_device *pfdev, u32 as_nr,
61			u64 region_start, u64 size)
62{
63	u8 region_width;
64	u64 region;
65	u64 region_end = region_start + size;
66
67	if (!size)
68		return;
69
70	/*
71	 * The locked region is a naturally aligned power of 2 block encoded as
72	 * log2 minus(1).
73	 * Calculate the desired start/end and look for the highest bit which
74	 * differs. The smallest naturally aligned block must include this bit
75	 * change, the desired region starts with this bit (and subsequent bits)
76	 * zeroed and ends with the bit (and subsequent bits) set to one.
77	 */
78	region_width = max(fls64(region_start ^ (region_end - 1)),
79			   const_ilog2(AS_LOCK_REGION_MIN_SIZE)) - 1;
80
81	/*
82	 * Mask off the low bits of region_start (which would be ignored by
83	 * the hardware anyway)
84	 */
85	region_start &= GENMASK_ULL(63, region_width);
86
87	region = region_width | region_start;
88
89	/* Lock the region that needs to be updated */
90	mmu_write(pfdev, AS_LOCKADDR_LO(as_nr), lower_32_bits(region));
91	mmu_write(pfdev, AS_LOCKADDR_HI(as_nr), upper_32_bits(region));
92	write_cmd(pfdev, as_nr, AS_COMMAND_LOCK);
93}
94
95
96static int mmu_hw_do_operation_locked(struct panfrost_device *pfdev, int as_nr,
97				      u64 iova, u64 size, u32 op)
98{
99	if (as_nr < 0)
100		return 0;
101
102	if (op != AS_COMMAND_UNLOCK)
103		lock_region(pfdev, as_nr, iova, size);
104
105	/* Run the MMU operation */
106	write_cmd(pfdev, as_nr, op);
107
108	/* Wait for the flush to complete */
109	return wait_ready(pfdev, as_nr);
110}
111
112static int mmu_hw_do_operation(struct panfrost_device *pfdev,
113			       struct panfrost_mmu *mmu,
114			       u64 iova, u64 size, u32 op)
115{
116	int ret;
117
118	spin_lock(&pfdev->as_lock);
119	ret = mmu_hw_do_operation_locked(pfdev, mmu->as, iova, size, op);
120	spin_unlock(&pfdev->as_lock);
121	return ret;
122}
123
124static void panfrost_mmu_enable(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
125{
126	int as_nr = mmu->as;
127	struct io_pgtable_cfg *cfg = &mmu->pgtbl_cfg;
128	u64 transtab = cfg->arm_mali_lpae_cfg.transtab;
129	u64 memattr = cfg->arm_mali_lpae_cfg.memattr;
130
131	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
132
133	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), lower_32_bits(transtab));
134	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), upper_32_bits(transtab));
135
136	/* Need to revisit mem attrs.
137	 * NC is the default, Mali driver is inner WT.
138	 */
139	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), lower_32_bits(memattr));
140	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), upper_32_bits(memattr));
141
142	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
143}
144
145static void panfrost_mmu_disable(struct panfrost_device *pfdev, u32 as_nr)
146{
147	mmu_hw_do_operation_locked(pfdev, as_nr, 0, ~0ULL, AS_COMMAND_FLUSH_MEM);
148
149	mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), 0);
150	mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), 0);
151
152	mmu_write(pfdev, AS_MEMATTR_LO(as_nr), 0);
153	mmu_write(pfdev, AS_MEMATTR_HI(as_nr), 0);
154
155	write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
156}
157
158u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
159{
160	int as;
161
162	spin_lock(&pfdev->as_lock);
163
164	as = mmu->as;
165	if (as >= 0) {
166		int en = atomic_inc_return(&mmu->as_count);
167		u32 mask = BIT(as) | BIT(16 + as);
168
169		/*
170		 * AS can be retained by active jobs or a perfcnt context,
171		 * hence the '+ 1' here.
172		 */
173		WARN_ON(en >= (NUM_JOB_SLOTS + 1));
174
175		list_move(&mmu->list, &pfdev->as_lru_list);
176
177		if (pfdev->as_faulty_mask & mask) {
178			/* Unhandled pagefault on this AS, the MMU was
179			 * disabled. We need to re-enable the MMU after
180			 * clearing+unmasking the AS interrupts.
181			 */
182			mmu_write(pfdev, MMU_INT_CLEAR, mask);
183			mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask);
184			pfdev->as_faulty_mask &= ~mask;
185			panfrost_mmu_enable(pfdev, mmu);
186		}
187
188		goto out;
189	}
190
191	/* Check for a free AS */
192	as = ffz(pfdev->as_alloc_mask);
193	if (!(BIT(as) & pfdev->features.as_present)) {
194		struct panfrost_mmu *lru_mmu;
195
196		list_for_each_entry_reverse(lru_mmu, &pfdev->as_lru_list, list) {
197			if (!atomic_read(&lru_mmu->as_count))
198				break;
199		}
200		WARN_ON(&lru_mmu->list == &pfdev->as_lru_list);
201
202		list_del_init(&lru_mmu->list);
203		as = lru_mmu->as;
204
205		WARN_ON(as < 0);
206		lru_mmu->as = -1;
207	}
208
209	/* Assign the free or reclaimed AS to the FD */
210	mmu->as = as;
211	set_bit(as, &pfdev->as_alloc_mask);
212	atomic_set(&mmu->as_count, 1);
213	list_add(&mmu->list, &pfdev->as_lru_list);
214
215	dev_dbg(pfdev->dev, "Assigned AS%d to mmu %p, alloc_mask=%lx", as, mmu, pfdev->as_alloc_mask);
216
217	panfrost_mmu_enable(pfdev, mmu);
218
219out:
220	spin_unlock(&pfdev->as_lock);
221	return as;
222}
223
224void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
225{
226	atomic_dec(&mmu->as_count);
227	WARN_ON(atomic_read(&mmu->as_count) < 0);
228}
229
230void panfrost_mmu_reset(struct panfrost_device *pfdev)
231{
232	struct panfrost_mmu *mmu, *mmu_tmp;
233
234	spin_lock(&pfdev->as_lock);
235
236	pfdev->as_alloc_mask = 0;
237	pfdev->as_faulty_mask = 0;
238
239	list_for_each_entry_safe(mmu, mmu_tmp, &pfdev->as_lru_list, list) {
240		mmu->as = -1;
241		atomic_set(&mmu->as_count, 0);
242		list_del_init(&mmu->list);
243	}
244
245	spin_unlock(&pfdev->as_lock);
246
247	mmu_write(pfdev, MMU_INT_CLEAR, ~0);
248	mmu_write(pfdev, MMU_INT_MASK, ~0);
249}
250
251static size_t get_pgsize(u64 addr, size_t size, size_t *count)
252{
253	/*
254	 * io-pgtable only operates on multiple pages within a single table
255	 * entry, so we need to split at boundaries of the table size, i.e.
256	 * the next block size up. The distance from address A to the next
257	 * boundary of block size B is logically B - A % B, but in unsigned
258	 * two's complement where B is a power of two we get the equivalence
259	 * B - A % B == (B - A) % B == (n * B - A) % B, and choose n = 0 :)
260	 */
261	size_t blk_offset = -addr % SZ_2M;
262
263	if (blk_offset || size < SZ_2M) {
264		*count = min_not_zero(blk_offset, size) / SZ_4K;
265		return SZ_4K;
266	}
267	blk_offset = -addr % SZ_1G ?: SZ_1G;
268	*count = min(blk_offset, size) / SZ_2M;
269	return SZ_2M;
270}
271
272static void panfrost_mmu_flush_range(struct panfrost_device *pfdev,
273				     struct panfrost_mmu *mmu,
274				     u64 iova, u64 size)
275{
276	if (mmu->as < 0)
277		return;
278
279	pm_runtime_get_noresume(pfdev->dev);
280
281	/* Flush the PTs only if we're already awake */
282	if (pm_runtime_active(pfdev->dev))
283		mmu_hw_do_operation(pfdev, mmu, iova, size, AS_COMMAND_FLUSH_PT);
284
285	pm_runtime_put_autosuspend(pfdev->dev);
286}
287
288static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
289		      u64 iova, int prot, struct sg_table *sgt)
290{
291	unsigned int count;
292	struct scatterlist *sgl;
293	struct io_pgtable_ops *ops = mmu->pgtbl_ops;
294	u64 start_iova = iova;
295
296	for_each_sgtable_dma_sg(sgt, sgl, count) {
297		unsigned long paddr = sg_dma_address(sgl);
298		size_t len = sg_dma_len(sgl);
299
300		dev_dbg(pfdev->dev, "map: as=%d, iova=%llx, paddr=%lx, len=%zx", mmu->as, iova, paddr, len);
301
302		while (len) {
303			size_t pgcount, mapped = 0;
304			size_t pgsize = get_pgsize(iova | paddr, len, &pgcount);
305
306			ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot,
307				       GFP_KERNEL, &mapped);
308			/* Don't get stuck if things have gone wrong */
309			mapped = max(mapped, pgsize);
310			iova += mapped;
311			paddr += mapped;
312			len -= mapped;
313		}
314	}
315
316	panfrost_mmu_flush_range(pfdev, mmu, start_iova, iova - start_iova);
317
318	return 0;
319}
320
321int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
322{
323	struct panfrost_gem_object *bo = mapping->obj;
324	struct drm_gem_shmem_object *shmem = &bo->base;
325	struct drm_gem_object *obj = &shmem->base;
326	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
327	struct sg_table *sgt;
328	int prot = IOMMU_READ | IOMMU_WRITE;
329
330	if (WARN_ON(mapping->active))
331		return 0;
332
333	if (bo->noexec)
334		prot |= IOMMU_NOEXEC;
335
336	sgt = drm_gem_shmem_get_pages_sgt(shmem);
337	if (WARN_ON(IS_ERR(sgt)))
338		return PTR_ERR(sgt);
339
340	mmu_map_sg(pfdev, mapping->mmu, mapping->mmnode.start << PAGE_SHIFT,
341		   prot, sgt);
342	mapping->active = true;
343
344	return 0;
345}
346
347void panfrost_mmu_unmap(struct panfrost_gem_mapping *mapping)
348{
349	struct panfrost_gem_object *bo = mapping->obj;
350	struct drm_gem_object *obj = &bo->base.base;
351	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
352	struct io_pgtable_ops *ops = mapping->mmu->pgtbl_ops;
353	u64 iova = mapping->mmnode.start << PAGE_SHIFT;
354	size_t len = mapping->mmnode.size << PAGE_SHIFT;
355	size_t unmapped_len = 0;
356
357	if (WARN_ON(!mapping->active))
358		return;
359
360	dev_dbg(pfdev->dev, "unmap: as=%d, iova=%llx, len=%zx",
361		mapping->mmu->as, iova, len);
362
363	while (unmapped_len < len) {
364		size_t unmapped_page, pgcount;
365		size_t pgsize = get_pgsize(iova, len - unmapped_len, &pgcount);
366
367		if (bo->is_heap)
368			pgcount = 1;
369		if (!bo->is_heap || ops->iova_to_phys(ops, iova)) {
370			unmapped_page = ops->unmap_pages(ops, iova, pgsize, pgcount, NULL);
371			WARN_ON(unmapped_page != pgsize * pgcount);
372		}
373		iova += pgsize * pgcount;
374		unmapped_len += pgsize * pgcount;
375	}
376
377	panfrost_mmu_flush_range(pfdev, mapping->mmu,
378				 mapping->mmnode.start << PAGE_SHIFT, len);
379	mapping->active = false;
380}
381
382static void mmu_tlb_inv_context_s1(void *cookie)
383{}
384
385static void mmu_tlb_sync_context(void *cookie)
386{
387	//struct panfrost_mmu *mmu = cookie;
388	// TODO: Wait 1000 GPU cycles for HW_ISSUE_6367/T60X
389}
390
391static void mmu_tlb_flush_walk(unsigned long iova, size_t size, size_t granule,
392			       void *cookie)
393{
394	mmu_tlb_sync_context(cookie);
395}
396
397static const struct iommu_flush_ops mmu_tlb_ops = {
398	.tlb_flush_all	= mmu_tlb_inv_context_s1,
399	.tlb_flush_walk = mmu_tlb_flush_walk,
400};
401
402static struct panfrost_gem_mapping *
403addr_to_mapping(struct panfrost_device *pfdev, int as, u64 addr)
404{
405	struct panfrost_gem_mapping *mapping = NULL;
406	struct drm_mm_node *node;
407	u64 offset = addr >> PAGE_SHIFT;
408	struct panfrost_mmu *mmu;
409
410	spin_lock(&pfdev->as_lock);
411	list_for_each_entry(mmu, &pfdev->as_lru_list, list) {
412		if (as == mmu->as)
413			goto found_mmu;
414	}
415	goto out;
416
417found_mmu:
418
419	spin_lock(&mmu->mm_lock);
420
421	drm_mm_for_each_node(node, &mmu->mm) {
422		if (offset >= node->start &&
423		    offset < (node->start + node->size)) {
424			mapping = drm_mm_node_to_panfrost_mapping(node);
425
426			kref_get(&mapping->refcount);
427			break;
428		}
429	}
430
431	spin_unlock(&mmu->mm_lock);
432out:
433	spin_unlock(&pfdev->as_lock);
434	return mapping;
435}
436
437#define NUM_FAULT_PAGES (SZ_2M / PAGE_SIZE)
438
439static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
440				       u64 addr)
441{
442	int ret, i;
443	struct panfrost_gem_mapping *bomapping;
444	struct panfrost_gem_object *bo;
445	struct address_space *mapping;
446	struct drm_gem_object *obj;
447	pgoff_t page_offset;
448	struct sg_table *sgt;
449	struct page **pages;
450
451	bomapping = addr_to_mapping(pfdev, as, addr);
452	if (!bomapping)
453		return -ENOENT;
454
455	bo = bomapping->obj;
456	if (!bo->is_heap) {
457		dev_WARN(pfdev->dev, "matching BO is not heap type (GPU VA = %llx)",
458			 bomapping->mmnode.start << PAGE_SHIFT);
459		ret = -EINVAL;
460		goto err_bo;
461	}
462	WARN_ON(bomapping->mmu->as != as);
463
464	/* Assume 2MB alignment and size multiple */
465	addr &= ~((u64)SZ_2M - 1);
466	page_offset = addr >> PAGE_SHIFT;
467	page_offset -= bomapping->mmnode.start;
468
469	obj = &bo->base.base;
470
471	dma_resv_lock(obj->resv, NULL);
472
473	if (!bo->base.pages) {
474		bo->sgts = kvmalloc_array(bo->base.base.size / SZ_2M,
475				     sizeof(struct sg_table), GFP_KERNEL | __GFP_ZERO);
476		if (!bo->sgts) {
477			ret = -ENOMEM;
478			goto err_unlock;
479		}
480
481		pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
482				       sizeof(struct page *), GFP_KERNEL | __GFP_ZERO);
483		if (!pages) {
484			kvfree(bo->sgts);
485			bo->sgts = NULL;
486			ret = -ENOMEM;
487			goto err_unlock;
488		}
489		bo->base.pages = pages;
490		bo->base.pages_use_count = 1;
491	} else {
492		pages = bo->base.pages;
493		if (pages[page_offset]) {
494			/* Pages are already mapped, bail out. */
495			goto out;
496		}
497	}
498
499	mapping = bo->base.base.filp->f_mapping;
500	mapping_set_unevictable(mapping);
501
502	for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
503		pages[i] = shmem_read_mapping_page(mapping, i);
504		if (IS_ERR(pages[i])) {
505			ret = PTR_ERR(pages[i]);
506			pages[i] = NULL;
507			goto err_pages;
508		}
509	}
510
511	sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
512	ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
513					NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL);
514	if (ret)
515		goto err_pages;
516
517	ret = dma_map_sgtable(pfdev->dev, sgt, DMA_BIDIRECTIONAL, 0);
518	if (ret)
519		goto err_map;
520
521	mmu_map_sg(pfdev, bomapping->mmu, addr,
522		   IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
523
524	bomapping->active = true;
525
526	dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
527
528out:
529	dma_resv_unlock(obj->resv);
530
531	panfrost_gem_mapping_put(bomapping);
532
533	return 0;
534
535err_map:
536	sg_free_table(sgt);
537err_pages:
538	drm_gem_shmem_put_pages(&bo->base);
539err_unlock:
540	dma_resv_unlock(obj->resv);
541err_bo:
542	panfrost_gem_mapping_put(bomapping);
543	return ret;
544}
545
546static void panfrost_mmu_release_ctx(struct kref *kref)
547{
548	struct panfrost_mmu *mmu = container_of(kref, struct panfrost_mmu,
549						refcount);
550	struct panfrost_device *pfdev = mmu->pfdev;
551
552	spin_lock(&pfdev->as_lock);
553	if (mmu->as >= 0) {
554		pm_runtime_get_noresume(pfdev->dev);
555		if (pm_runtime_active(pfdev->dev))
556			panfrost_mmu_disable(pfdev, mmu->as);
557		pm_runtime_put_autosuspend(pfdev->dev);
558
559		clear_bit(mmu->as, &pfdev->as_alloc_mask);
560		clear_bit(mmu->as, &pfdev->as_in_use_mask);
561		list_del(&mmu->list);
562	}
563	spin_unlock(&pfdev->as_lock);
564
565	free_io_pgtable_ops(mmu->pgtbl_ops);
566	drm_mm_takedown(&mmu->mm);
567	kfree(mmu);
568}
569
570void panfrost_mmu_ctx_put(struct panfrost_mmu *mmu)
571{
572	kref_put(&mmu->refcount, panfrost_mmu_release_ctx);
573}
574
575struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu)
576{
577	kref_get(&mmu->refcount);
578
579	return mmu;
580}
581
582#define PFN_4G		(SZ_4G >> PAGE_SHIFT)
583#define PFN_4G_MASK	(PFN_4G - 1)
584#define PFN_16M		(SZ_16M >> PAGE_SHIFT)
585
586static void panfrost_drm_mm_color_adjust(const struct drm_mm_node *node,
587					 unsigned long color,
588					 u64 *start, u64 *end)
589{
590	/* Executable buffers can't start or end on a 4GB boundary */
591	if (!(color & PANFROST_BO_NOEXEC)) {
592		u64 next_seg;
593
594		if ((*start & PFN_4G_MASK) == 0)
595			(*start)++;
596
597		if ((*end & PFN_4G_MASK) == 0)
598			(*end)--;
599
600		next_seg = ALIGN(*start, PFN_4G);
601		if (next_seg - *start <= PFN_16M)
602			*start = next_seg + 1;
603
604		*end = min(*end, ALIGN(*start, PFN_4G) - 1);
605	}
606}
607
608struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev)
609{
610	struct panfrost_mmu *mmu;
611
612	mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
613	if (!mmu)
614		return ERR_PTR(-ENOMEM);
615
616	mmu->pfdev = pfdev;
617	spin_lock_init(&mmu->mm_lock);
618
619	/* 4G enough for now. can be 48-bit */
620	drm_mm_init(&mmu->mm, SZ_32M >> PAGE_SHIFT, (SZ_4G - SZ_32M) >> PAGE_SHIFT);
621	mmu->mm.color_adjust = panfrost_drm_mm_color_adjust;
622
623	INIT_LIST_HEAD(&mmu->list);
624	mmu->as = -1;
625
626	mmu->pgtbl_cfg = (struct io_pgtable_cfg) {
627		.pgsize_bitmap	= SZ_4K | SZ_2M,
628		.ias		= FIELD_GET(0xff, pfdev->features.mmu_features),
629		.oas		= FIELD_GET(0xff00, pfdev->features.mmu_features),
630		.coherent_walk	= pfdev->coherent,
631		.tlb		= &mmu_tlb_ops,
632		.iommu_dev	= pfdev->dev,
633	};
634
635	mmu->pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &mmu->pgtbl_cfg,
636					      mmu);
637	if (!mmu->pgtbl_ops) {
638		kfree(mmu);
639		return ERR_PTR(-EINVAL);
640	}
641
642	kref_init(&mmu->refcount);
643
644	return mmu;
645}
646
647static const char *access_type_name(struct panfrost_device *pfdev,
648		u32 fault_status)
649{
650	switch (fault_status & AS_FAULTSTATUS_ACCESS_TYPE_MASK) {
651	case AS_FAULTSTATUS_ACCESS_TYPE_ATOMIC:
652		if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU))
653			return "ATOMIC";
654		else
655			return "UNKNOWN";
656	case AS_FAULTSTATUS_ACCESS_TYPE_READ:
657		return "READ";
658	case AS_FAULTSTATUS_ACCESS_TYPE_WRITE:
659		return "WRITE";
660	case AS_FAULTSTATUS_ACCESS_TYPE_EX:
661		return "EXECUTE";
662	default:
663		WARN_ON(1);
664		return NULL;
665	}
666}
667
668static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data)
669{
670	struct panfrost_device *pfdev = data;
671
672	if (!mmu_read(pfdev, MMU_INT_STAT))
673		return IRQ_NONE;
674
675	mmu_write(pfdev, MMU_INT_MASK, 0);
676	return IRQ_WAKE_THREAD;
677}
678
679static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
680{
681	struct panfrost_device *pfdev = data;
682	u32 status = mmu_read(pfdev, MMU_INT_RAWSTAT);
683	int ret;
684
685	while (status) {
686		u32 as = ffs(status | (status >> 16)) - 1;
687		u32 mask = BIT(as) | BIT(as + 16);
688		u64 addr;
689		u32 fault_status;
690		u32 exception_type;
691		u32 access_type;
692		u32 source_id;
693
694		fault_status = mmu_read(pfdev, AS_FAULTSTATUS(as));
695		addr = mmu_read(pfdev, AS_FAULTADDRESS_LO(as));
696		addr |= (u64)mmu_read(pfdev, AS_FAULTADDRESS_HI(as)) << 32;
697
698		/* decode the fault status */
699		exception_type = fault_status & 0xFF;
700		access_type = (fault_status >> 8) & 0x3;
701		source_id = (fault_status >> 16);
702
703		mmu_write(pfdev, MMU_INT_CLEAR, mask);
704
705		/* Page fault only */
706		ret = -1;
707		if ((status & mask) == BIT(as) && (exception_type & 0xF8) == 0xC0)
708			ret = panfrost_mmu_map_fault_addr(pfdev, as, addr);
709
710		if (ret) {
711			/* terminal fault, print info about the fault */
712			dev_err(pfdev->dev,
713				"Unhandled Page fault in AS%d at VA 0x%016llX\n"
714				"Reason: %s\n"
715				"raw fault status: 0x%X\n"
716				"decoded fault status: %s\n"
717				"exception type 0x%X: %s\n"
718				"access type 0x%X: %s\n"
719				"source id 0x%X\n",
720				as, addr,
721				"TODO",
722				fault_status,
723				(fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE FAULT"),
724				exception_type, panfrost_exception_name(exception_type),
725				access_type, access_type_name(pfdev, fault_status),
726				source_id);
727
728			spin_lock(&pfdev->as_lock);
729			/* Ignore MMU interrupts on this AS until it's been
730			 * re-enabled.
731			 */
732			pfdev->as_faulty_mask |= mask;
733
734			/* Disable the MMU to kill jobs on this AS. */
735			panfrost_mmu_disable(pfdev, as);
736			spin_unlock(&pfdev->as_lock);
737		}
738
739		status &= ~mask;
740
741		/* If we received new MMU interrupts, process them before returning. */
742		if (!status)
743			status = mmu_read(pfdev, MMU_INT_RAWSTAT) & ~pfdev->as_faulty_mask;
744	}
745
746	spin_lock(&pfdev->as_lock);
747	mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask);
748	spin_unlock(&pfdev->as_lock);
749
750	return IRQ_HANDLED;
751};
752
753int panfrost_mmu_init(struct panfrost_device *pfdev)
754{
755	int err, irq;
756
757	irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "mmu");
758	if (irq <= 0)
759		return -ENODEV;
760
761	err = devm_request_threaded_irq(pfdev->dev, irq,
762					panfrost_mmu_irq_handler,
763					panfrost_mmu_irq_handler_thread,
764					IRQF_SHARED, KBUILD_MODNAME "-mmu",
765					pfdev);
766
767	if (err) {
768		dev_err(pfdev->dev, "failed to request mmu irq");
769		return err;
770	}
771
772	return 0;
773}
774
775void panfrost_mmu_fini(struct panfrost_device *pfdev)
776{
777	mmu_write(pfdev, MMU_INT_MASK, 0);
778}
779