1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2015-2018 Etnaviv Project
4  */
5 
6 #include <linux/dma-mapping.h>
7 #include <linux/scatterlist.h>
8 
9 #include "common.xml.h"
10 #include "etnaviv_cmdbuf.h"
11 #include "etnaviv_drv.h"
12 #include "etnaviv_gem.h"
13 #include "etnaviv_gpu.h"
14 #include "etnaviv_mmu.h"
15 
16 static void etnaviv_context_unmap(struct etnaviv_iommu_context *context,
17 				 unsigned long iova, size_t size)
18 {
19 	size_t unmapped_page, unmapped = 0;
20 	size_t pgsize = SZ_4K;
21 
22 	if (!IS_ALIGNED(iova | size, pgsize)) {
23 		pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%zx\n",
24 		       iova, size, pgsize);
25 		return;
26 	}
27 
28 	while (unmapped < size) {
29 		unmapped_page = context->global->ops->unmap(context, iova,
30 							    pgsize);
31 		if (!unmapped_page)
32 			break;
33 
34 		iova += unmapped_page;
35 		unmapped += unmapped_page;
36 	}
37 }
38 
39 static int etnaviv_context_map(struct etnaviv_iommu_context *context,
40 			      unsigned long iova, phys_addr_t paddr,
41 			      size_t size, int prot)
42 {
43 	unsigned long orig_iova = iova;
44 	size_t pgsize = SZ_4K;
45 	size_t orig_size = size;
46 	int ret = 0;
47 
48 	if (!IS_ALIGNED(iova | paddr | size, pgsize)) {
49 		pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%zx\n",
50 		       iova, &paddr, size, pgsize);
51 		return -EINVAL;
52 	}
53 
54 	while (size) {
55 		ret = context->global->ops->map(context, iova, paddr, pgsize,
56 						prot);
57 		if (ret)
58 			break;
59 
60 		iova += pgsize;
61 		paddr += pgsize;
62 		size -= pgsize;
63 	}
64 
65 	/* unroll mapping in case something went wrong */
66 	if (ret)
67 		etnaviv_context_unmap(context, orig_iova, orig_size - size);
68 
69 	return ret;
70 }
71 
72 static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova,
73 			     struct sg_table *sgt, unsigned len, int prot)
74 {	struct scatterlist *sg;
75 	unsigned int da = iova;
76 	unsigned int i;
77 	int ret;
78 
79 	if (!context || !sgt)
80 		return -EINVAL;
81 
82 	for_each_sgtable_dma_sg(sgt, sg, i) {
83 		u32 pa = sg_dma_address(sg) - sg->offset;
84 		size_t bytes = sg_dma_len(sg) + sg->offset;
85 
86 		VERB("map[%d]: %08x %08x(%zx)", i, iova, pa, bytes);
87 
88 		ret = etnaviv_context_map(context, da, pa, bytes, prot);
89 		if (ret)
90 			goto fail;
91 
92 		da += bytes;
93 	}
94 
95 	context->flush_seq++;
96 
97 	return 0;
98 
99 fail:
100 	etnaviv_context_unmap(context, iova, da - iova);
101 	return ret;
102 }
103 
104 static void etnaviv_iommu_unmap(struct etnaviv_iommu_context *context, u32 iova,
105 				struct sg_table *sgt, unsigned len)
106 {
107 	struct scatterlist *sg;
108 	unsigned int da = iova;
109 	int i;
110 
111 	for_each_sgtable_dma_sg(sgt, sg, i) {
112 		size_t bytes = sg_dma_len(sg) + sg->offset;
113 
114 		etnaviv_context_unmap(context, da, bytes);
115 
116 		VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);
117 
118 		BUG_ON(!PAGE_ALIGNED(bytes));
119 
120 		da += bytes;
121 	}
122 
123 	context->flush_seq++;
124 }
125 
126 static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu_context *context,
127 	struct etnaviv_vram_mapping *mapping)
128 {
129 	struct etnaviv_gem_object *etnaviv_obj = mapping->object;
130 
131 	lockdep_assert_held(&context->lock);
132 
133 	etnaviv_iommu_unmap(context, mapping->vram_node.start,
134 			    etnaviv_obj->sgt, etnaviv_obj->base.size);
135 	drm_mm_remove_node(&mapping->vram_node);
136 }
137 
138 static int etnaviv_iommu_find_iova(struct etnaviv_iommu_context *context,
139 				   struct drm_mm_node *node, size_t size)
140 {
141 	struct etnaviv_vram_mapping *free = NULL;
142 	enum drm_mm_insert_mode mode = DRM_MM_INSERT_LOW;
143 	int ret;
144 
145 	lockdep_assert_held(&context->lock);
146 
147 	while (1) {
148 		struct etnaviv_vram_mapping *m, *n;
149 		struct drm_mm_scan scan;
150 		struct list_head list;
151 		bool found;
152 
153 		ret = drm_mm_insert_node_in_range(&context->mm, node,
154 						  size, 0, 0, 0, U64_MAX, mode);
155 		if (ret != -ENOSPC)
156 			break;
157 
158 		/* Try to retire some entries */
159 		drm_mm_scan_init(&scan, &context->mm, size, 0, 0, mode);
160 
161 		found = 0;
162 		INIT_LIST_HEAD(&list);
163 		list_for_each_entry(free, &context->mappings, mmu_node) {
164 			/* If this vram node has not been used, skip this. */
165 			if (!free->vram_node.mm)
166 				continue;
167 
168 			/*
169 			 * If the iova is pinned, then it's in-use,
170 			 * so we must keep its mapping.
171 			 */
172 			if (free->use)
173 				continue;
174 
175 			list_add(&free->scan_node, &list);
176 			if (drm_mm_scan_add_block(&scan, &free->vram_node)) {
177 				found = true;
178 				break;
179 			}
180 		}
181 
182 		if (!found) {
183 			/* Nothing found, clean up and fail */
184 			list_for_each_entry_safe(m, n, &list, scan_node)
185 				BUG_ON(drm_mm_scan_remove_block(&scan, &m->vram_node));
186 			break;
187 		}
188 
189 		/*
190 		 * drm_mm does not allow any other operations while
191 		 * scanning, so we have to remove all blocks first.
192 		 * If drm_mm_scan_remove_block() returns false, we
193 		 * can leave the block pinned.
194 		 */
195 		list_for_each_entry_safe(m, n, &list, scan_node)
196 			if (!drm_mm_scan_remove_block(&scan, &m->vram_node))
197 				list_del_init(&m->scan_node);
198 
199 		/*
200 		 * Unmap the blocks which need to be reaped from the MMU.
201 		 * Clear the mmu pointer to prevent the mapping_get finding
202 		 * this mapping.
203 		 */
204 		list_for_each_entry_safe(m, n, &list, scan_node) {
205 			etnaviv_iommu_remove_mapping(context, m);
206 			etnaviv_iommu_context_put(m->context);
207 			m->context = NULL;
208 			list_del_init(&m->mmu_node);
209 			list_del_init(&m->scan_node);
210 		}
211 
212 		mode = DRM_MM_INSERT_EVICT;
213 
214 		/*
215 		 * We removed enough mappings so that the new allocation will
216 		 * succeed, retry the allocation one more time.
217 		 */
218 	}
219 
220 	return ret;
221 }
222 
223 static int etnaviv_iommu_insert_exact(struct etnaviv_iommu_context *context,
224 		   struct drm_mm_node *node, size_t size, u64 va)
225 {
226 	struct etnaviv_vram_mapping *m, *n;
227 	struct drm_mm_node *scan_node;
228 	LIST_HEAD(scan_list);
229 	int ret;
230 
231 	lockdep_assert_held(&context->lock);
232 
233 	ret = drm_mm_insert_node_in_range(&context->mm, node, size, 0, 0, va,
234 					  va + size, DRM_MM_INSERT_LOWEST);
235 	if (ret != -ENOSPC)
236 		return ret;
237 
238 	/*
239 	 * When we can't insert the node, due to a existing mapping blocking
240 	 * the address space, there are two possible reasons:
241 	 * 1. Userspace genuinely messed up and tried to reuse address space
242 	 * before the last job using this VMA has finished executing.
243 	 * 2. The existing buffer mappings are idle, but the buffers are not
244 	 * destroyed yet (likely due to being referenced by another context) in
245 	 * which case the mappings will not be cleaned up and we must reap them
246 	 * here to make space for the new mapping.
247 	 */
248 
249 	drm_mm_for_each_node_in_range(scan_node, &context->mm, va, va + size) {
250 		m = container_of(scan_node, struct etnaviv_vram_mapping,
251 				 vram_node);
252 
253 		if (m->use)
254 			return -ENOSPC;
255 
256 		list_add(&m->scan_node, &scan_list);
257 	}
258 
259 	list_for_each_entry_safe(m, n, &scan_list, scan_node) {
260 		etnaviv_iommu_remove_mapping(context, m);
261 		etnaviv_iommu_context_put(m->context);
262 		m->context = NULL;
263 		list_del_init(&m->mmu_node);
264 		list_del_init(&m->scan_node);
265 	}
266 
267 	return drm_mm_insert_node_in_range(&context->mm, node, size, 0, 0, va,
268 					   va + size, DRM_MM_INSERT_LOWEST);
269 }
270 
271 int etnaviv_iommu_map_gem(struct etnaviv_iommu_context *context,
272 	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
273 	struct etnaviv_vram_mapping *mapping, u64 va)
274 {
275 	struct sg_table *sgt = etnaviv_obj->sgt;
276 	struct drm_mm_node *node;
277 	int ret;
278 
279 	lockdep_assert_held(&etnaviv_obj->lock);
280 
281 	mutex_lock(&context->lock);
282 
283 	/* v1 MMU can optimize single entry (contiguous) scatterlists */
284 	if (context->global->version == ETNAVIV_IOMMU_V1 &&
285 	    sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
286 		u32 iova;
287 
288 		iova = sg_dma_address(sgt->sgl) - memory_base;
289 		if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
290 			mapping->iova = iova;
291 			mapping->context = etnaviv_iommu_context_get(context);
292 			list_add_tail(&mapping->mmu_node, &context->mappings);
293 			ret = 0;
294 			goto unlock;
295 		}
296 	}
297 
298 	node = &mapping->vram_node;
299 
300 	if (va)
301 		ret = etnaviv_iommu_insert_exact(context, node,
302 						 etnaviv_obj->base.size, va);
303 	else
304 		ret = etnaviv_iommu_find_iova(context, node,
305 					      etnaviv_obj->base.size);
306 	if (ret < 0)
307 		goto unlock;
308 
309 	mapping->iova = node->start;
310 	ret = etnaviv_iommu_map(context, node->start, sgt, etnaviv_obj->base.size,
311 				ETNAVIV_PROT_READ | ETNAVIV_PROT_WRITE);
312 
313 	if (ret < 0) {
314 		drm_mm_remove_node(node);
315 		goto unlock;
316 	}
317 
318 	mapping->context = etnaviv_iommu_context_get(context);
319 	list_add_tail(&mapping->mmu_node, &context->mappings);
320 unlock:
321 	mutex_unlock(&context->lock);
322 
323 	return ret;
324 }
325 
326 void etnaviv_iommu_unmap_gem(struct etnaviv_iommu_context *context,
327 	struct etnaviv_vram_mapping *mapping)
328 {
329 	WARN_ON(mapping->use);
330 
331 	mutex_lock(&context->lock);
332 
333 	/* Bail if the mapping has been reaped by another thread */
334 	if (!mapping->context) {
335 		mutex_unlock(&context->lock);
336 		return;
337 	}
338 
339 	/* If the vram node is on the mm, unmap and remove the node */
340 	if (mapping->vram_node.mm == &context->mm)
341 		etnaviv_iommu_remove_mapping(context, mapping);
342 
343 	list_del(&mapping->mmu_node);
344 	mutex_unlock(&context->lock);
345 	etnaviv_iommu_context_put(context);
346 }
347 
348 static void etnaviv_iommu_context_free(struct kref *kref)
349 {
350 	struct etnaviv_iommu_context *context =
351 		container_of(kref, struct etnaviv_iommu_context, refcount);
352 
353 	etnaviv_cmdbuf_suballoc_unmap(context, &context->cmdbuf_mapping);
354 
355 	context->global->ops->free(context);
356 }
357 void etnaviv_iommu_context_put(struct etnaviv_iommu_context *context)
358 {
359 	kref_put(&context->refcount, etnaviv_iommu_context_free);
360 }
361 
362 struct etnaviv_iommu_context *
363 etnaviv_iommu_context_init(struct etnaviv_iommu_global *global,
364 			   struct etnaviv_cmdbuf_suballoc *suballoc)
365 {
366 	struct etnaviv_iommu_context *ctx;
367 	int ret;
368 
369 	if (global->version == ETNAVIV_IOMMU_V1)
370 		ctx = etnaviv_iommuv1_context_alloc(global);
371 	else
372 		ctx = etnaviv_iommuv2_context_alloc(global);
373 
374 	if (!ctx)
375 		return NULL;
376 
377 	ret = etnaviv_cmdbuf_suballoc_map(suballoc, ctx, &ctx->cmdbuf_mapping,
378 					  global->memory_base);
379 	if (ret)
380 		goto out_free;
381 
382 	if (global->version == ETNAVIV_IOMMU_V1 &&
383 	    ctx->cmdbuf_mapping.iova > 0x80000000) {
384 		dev_err(global->dev,
385 		        "command buffer outside valid memory window\n");
386 		goto out_unmap;
387 	}
388 
389 	return ctx;
390 
391 out_unmap:
392 	etnaviv_cmdbuf_suballoc_unmap(ctx, &ctx->cmdbuf_mapping);
393 out_free:
394 	global->ops->free(ctx);
395 	return NULL;
396 }
397 
398 void etnaviv_iommu_restore(struct etnaviv_gpu *gpu,
399 			   struct etnaviv_iommu_context *context)
400 {
401 	context->global->ops->restore(gpu, context);
402 }
403 
404 int etnaviv_iommu_get_suballoc_va(struct etnaviv_iommu_context *context,
405 				  struct etnaviv_vram_mapping *mapping,
406 				  u32 memory_base, dma_addr_t paddr,
407 				  size_t size)
408 {
409 	mutex_lock(&context->lock);
410 
411 	if (mapping->use > 0) {
412 		mapping->use++;
413 		mutex_unlock(&context->lock);
414 		return 0;
415 	}
416 
417 	/*
418 	 * For MMUv1 we don't add the suballoc region to the pagetables, as
419 	 * those GPUs can only work with cmdbufs accessed through the linear
420 	 * window. Instead we manufacture a mapping to make it look uniform
421 	 * to the upper layers.
422 	 */
423 	if (context->global->version == ETNAVIV_IOMMU_V1) {
424 		mapping->iova = paddr - memory_base;
425 	} else {
426 		struct drm_mm_node *node = &mapping->vram_node;
427 		int ret;
428 
429 		ret = etnaviv_iommu_find_iova(context, node, size);
430 		if (ret < 0) {
431 			mutex_unlock(&context->lock);
432 			return ret;
433 		}
434 
435 		mapping->iova = node->start;
436 		ret = etnaviv_context_map(context, node->start, paddr, size,
437 					  ETNAVIV_PROT_READ);
438 		if (ret < 0) {
439 			drm_mm_remove_node(node);
440 			mutex_unlock(&context->lock);
441 			return ret;
442 		}
443 
444 		context->flush_seq++;
445 	}
446 
447 	list_add_tail(&mapping->mmu_node, &context->mappings);
448 	mapping->use = 1;
449 
450 	mutex_unlock(&context->lock);
451 
452 	return 0;
453 }
454 
455 void etnaviv_iommu_put_suballoc_va(struct etnaviv_iommu_context *context,
456 		  struct etnaviv_vram_mapping *mapping)
457 {
458 	struct drm_mm_node *node = &mapping->vram_node;
459 
460 	mutex_lock(&context->lock);
461 	mapping->use--;
462 
463 	if (mapping->use > 0 || context->global->version == ETNAVIV_IOMMU_V1) {
464 		mutex_unlock(&context->lock);
465 		return;
466 	}
467 
468 	etnaviv_context_unmap(context, node->start, node->size);
469 	drm_mm_remove_node(node);
470 	mutex_unlock(&context->lock);
471 }
472 
473 size_t etnaviv_iommu_dump_size(struct etnaviv_iommu_context *context)
474 {
475 	return context->global->ops->dump_size(context);
476 }
477 
478 void etnaviv_iommu_dump(struct etnaviv_iommu_context *context, void *buf)
479 {
480 	context->global->ops->dump(context, buf);
481 }
482 
483 int etnaviv_iommu_global_init(struct etnaviv_gpu *gpu)
484 {
485 	enum etnaviv_iommu_version version = ETNAVIV_IOMMU_V1;
486 	struct etnaviv_drm_private *priv = gpu->drm->dev_private;
487 	struct etnaviv_iommu_global *global;
488 	struct device *dev = gpu->drm->dev;
489 
490 	if (gpu->identity.minor_features1 & chipMinorFeatures1_MMU_VERSION)
491 		version = ETNAVIV_IOMMU_V2;
492 
493 	if (priv->mmu_global) {
494 		if (priv->mmu_global->version != version) {
495 			dev_err(gpu->dev,
496 				"MMU version doesn't match global version\n");
497 			return -ENXIO;
498 		}
499 
500 		priv->mmu_global->use++;
501 		return 0;
502 	}
503 
504 	global = kzalloc(sizeof(*global), GFP_KERNEL);
505 	if (!global)
506 		return -ENOMEM;
507 
508 	global->bad_page_cpu = dma_alloc_wc(dev, SZ_4K, &global->bad_page_dma,
509 					    GFP_KERNEL);
510 	if (!global->bad_page_cpu)
511 		goto free_global;
512 
513 	memset32(global->bad_page_cpu, 0xdead55aa, SZ_4K / sizeof(u32));
514 
515 	if (version == ETNAVIV_IOMMU_V2) {
516 		global->v2.pta_cpu = dma_alloc_wc(dev, ETNAVIV_PTA_SIZE,
517 					       &global->v2.pta_dma, GFP_KERNEL);
518 		if (!global->v2.pta_cpu)
519 			goto free_bad_page;
520 	}
521 
522 	global->dev = dev;
523 	global->version = version;
524 	global->use = 1;
525 	mutex_init(&global->lock);
526 
527 	if (version == ETNAVIV_IOMMU_V1)
528 		global->ops = &etnaviv_iommuv1_ops;
529 	else
530 		global->ops = &etnaviv_iommuv2_ops;
531 
532 	priv->mmu_global = global;
533 
534 	return 0;
535 
536 free_bad_page:
537 	dma_free_wc(dev, SZ_4K, global->bad_page_cpu, global->bad_page_dma);
538 free_global:
539 	kfree(global);
540 
541 	return -ENOMEM;
542 }
543 
544 void etnaviv_iommu_global_fini(struct etnaviv_gpu *gpu)
545 {
546 	struct etnaviv_drm_private *priv = gpu->drm->dev_private;
547 	struct etnaviv_iommu_global *global = priv->mmu_global;
548 
549 	if (--global->use > 0)
550 		return;
551 
552 	if (global->v2.pta_cpu)
553 		dma_free_wc(global->dev, ETNAVIV_PTA_SIZE,
554 			    global->v2.pta_cpu, global->v2.pta_dma);
555 
556 	if (global->bad_page_cpu)
557 		dma_free_wc(global->dev, SZ_4K,
558 			    global->bad_page_cpu, global->bad_page_dma);
559 
560 	mutex_destroy(&global->lock);
561 	kfree(global);
562 
563 	priv->mmu_global = NULL;
564 }
565