etnaviv_mmu.c

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