xref: /linux/drivers/gpu/drm/etnaviv/etnaviv_mmu.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2015-2018 Etnaviv Project
4  */
5 
6 #include "common.xml.h"
7 #include "etnaviv_cmdbuf.h"
8 #include "etnaviv_drv.h"
9 #include "etnaviv_gem.h"
10 #include "etnaviv_gpu.h"
11 #include "etnaviv_iommu.h"
12 #include "etnaviv_mmu.h"
13 
14 static void etnaviv_domain_unmap(struct etnaviv_iommu_domain *domain,
15 				 unsigned long iova, size_t size)
16 {
17 	size_t unmapped_page, unmapped = 0;
18 	size_t pgsize = SZ_4K;
19 
20 	if (!IS_ALIGNED(iova | size, pgsize)) {
21 		pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%zx\n",
22 		       iova, size, pgsize);
23 		return;
24 	}
25 
26 	while (unmapped < size) {
27 		unmapped_page = domain->ops->unmap(domain, iova, pgsize);
28 		if (!unmapped_page)
29 			break;
30 
31 		iova += unmapped_page;
32 		unmapped += unmapped_page;
33 	}
34 }
35 
36 static int etnaviv_domain_map(struct etnaviv_iommu_domain *domain,
37 			      unsigned long iova, phys_addr_t paddr,
38 			      size_t size, int prot)
39 {
40 	unsigned long orig_iova = iova;
41 	size_t pgsize = SZ_4K;
42 	size_t orig_size = size;
43 	int ret = 0;
44 
45 	if (!IS_ALIGNED(iova | paddr | size, pgsize)) {
46 		pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%zx\n",
47 		       iova, &paddr, size, pgsize);
48 		return -EINVAL;
49 	}
50 
51 	while (size) {
52 		ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
53 		if (ret)
54 			break;
55 
56 		iova += pgsize;
57 		paddr += pgsize;
58 		size -= pgsize;
59 	}
60 
61 	/* unroll mapping in case something went wrong */
62 	if (ret)
63 		etnaviv_domain_unmap(domain, orig_iova, orig_size - size);
64 
65 	return ret;
66 }
67 
68 static int etnaviv_iommu_map(struct etnaviv_iommu *iommu, u32 iova,
69 			     struct sg_table *sgt, unsigned len, int prot)
70 {
71 	struct etnaviv_iommu_domain *domain = iommu->domain;
72 	struct scatterlist *sg;
73 	unsigned int da = iova;
74 	unsigned int i, j;
75 	int ret;
76 
77 	if (!domain || !sgt)
78 		return -EINVAL;
79 
80 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
81 		u32 pa = sg_dma_address(sg) - sg->offset;
82 		size_t bytes = sg_dma_len(sg) + sg->offset;
83 
84 		VERB("map[%d]: %08x %08x(%zx)", i, iova, pa, bytes);
85 
86 		ret = etnaviv_domain_map(domain, da, pa, bytes, prot);
87 		if (ret)
88 			goto fail;
89 
90 		da += bytes;
91 	}
92 
93 	return 0;
94 
95 fail:
96 	da = iova;
97 
98 	for_each_sg(sgt->sgl, sg, i, j) {
99 		size_t bytes = sg_dma_len(sg) + sg->offset;
100 
101 		etnaviv_domain_unmap(domain, da, bytes);
102 		da += bytes;
103 	}
104 	return ret;
105 }
106 
107 static void etnaviv_iommu_unmap(struct etnaviv_iommu *iommu, u32 iova,
108 				struct sg_table *sgt, unsigned len)
109 {
110 	struct etnaviv_iommu_domain *domain = iommu->domain;
111 	struct scatterlist *sg;
112 	unsigned int da = iova;
113 	int i;
114 
115 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
116 		size_t bytes = sg_dma_len(sg) + sg->offset;
117 
118 		etnaviv_domain_unmap(domain, da, bytes);
119 
120 		VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);
121 
122 		BUG_ON(!PAGE_ALIGNED(bytes));
123 
124 		da += bytes;
125 	}
126 }
127 
128 static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu *mmu,
129 	struct etnaviv_vram_mapping *mapping)
130 {
131 	struct etnaviv_gem_object *etnaviv_obj = mapping->object;
132 
133 	etnaviv_iommu_unmap(mmu, 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 *mmu,
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(&mmu->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(&mmu->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, &mmu->mm, size, 0, 0, mode);
160 
161 		found = 0;
162 		INIT_LIST_HEAD(&list);
163 		list_for_each_entry(free, &mmu->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(mmu, m);
206 			m->mmu = NULL;
207 			list_del_init(&m->mmu_node);
208 			list_del_init(&m->scan_node);
209 		}
210 
211 		mode = DRM_MM_INSERT_EVICT;
212 
213 		/*
214 		 * We removed enough mappings so that the new allocation will
215 		 * succeed, retry the allocation one more time.
216 		 */
217 	}
218 
219 	return ret;
220 }
221 
222 int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
223 	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
224 	struct etnaviv_vram_mapping *mapping)
225 {
226 	struct sg_table *sgt = etnaviv_obj->sgt;
227 	struct drm_mm_node *node;
228 	int ret;
229 
230 	lockdep_assert_held(&etnaviv_obj->lock);
231 
232 	mutex_lock(&mmu->lock);
233 
234 	/* v1 MMU can optimize single entry (contiguous) scatterlists */
235 	if (mmu->version == ETNAVIV_IOMMU_V1 &&
236 	    sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
237 		u32 iova;
238 
239 		iova = sg_dma_address(sgt->sgl) - memory_base;
240 		if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
241 			mapping->iova = iova;
242 			list_add_tail(&mapping->mmu_node, &mmu->mappings);
243 			ret = 0;
244 			goto unlock;
245 		}
246 	}
247 
248 	node = &mapping->vram_node;
249 
250 	ret = etnaviv_iommu_find_iova(mmu, node, etnaviv_obj->base.size);
251 	if (ret < 0)
252 		goto unlock;
253 
254 	mapping->iova = node->start;
255 	ret = etnaviv_iommu_map(mmu, node->start, sgt, etnaviv_obj->base.size,
256 				ETNAVIV_PROT_READ | ETNAVIV_PROT_WRITE);
257 
258 	if (ret < 0) {
259 		drm_mm_remove_node(node);
260 		goto unlock;
261 	}
262 
263 	list_add_tail(&mapping->mmu_node, &mmu->mappings);
264 	mmu->need_flush = true;
265 unlock:
266 	mutex_unlock(&mmu->lock);
267 
268 	return ret;
269 }
270 
271 void etnaviv_iommu_unmap_gem(struct etnaviv_iommu *mmu,
272 	struct etnaviv_vram_mapping *mapping)
273 {
274 	WARN_ON(mapping->use);
275 
276 	mutex_lock(&mmu->lock);
277 
278 	/* If the vram node is on the mm, unmap and remove the node */
279 	if (mapping->vram_node.mm == &mmu->mm)
280 		etnaviv_iommu_remove_mapping(mmu, mapping);
281 
282 	list_del(&mapping->mmu_node);
283 	mmu->need_flush = true;
284 	mutex_unlock(&mmu->lock);
285 }
286 
287 void etnaviv_iommu_destroy(struct etnaviv_iommu *mmu)
288 {
289 	drm_mm_takedown(&mmu->mm);
290 	mmu->domain->ops->free(mmu->domain);
291 	kfree(mmu);
292 }
293 
294 struct etnaviv_iommu *etnaviv_iommu_new(struct etnaviv_gpu *gpu)
295 {
296 	enum etnaviv_iommu_version version;
297 	struct etnaviv_iommu *mmu;
298 
299 	mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
300 	if (!mmu)
301 		return ERR_PTR(-ENOMEM);
302 
303 	if (!(gpu->identity.minor_features1 & chipMinorFeatures1_MMU_VERSION)) {
304 		mmu->domain = etnaviv_iommuv1_domain_alloc(gpu);
305 		version = ETNAVIV_IOMMU_V1;
306 	} else {
307 		mmu->domain = etnaviv_iommuv2_domain_alloc(gpu);
308 		version = ETNAVIV_IOMMU_V2;
309 	}
310 
311 	if (!mmu->domain) {
312 		dev_err(gpu->dev, "Failed to allocate GPU IOMMU domain\n");
313 		kfree(mmu);
314 		return ERR_PTR(-ENOMEM);
315 	}
316 
317 	mmu->gpu = gpu;
318 	mmu->version = version;
319 	mutex_init(&mmu->lock);
320 	INIT_LIST_HEAD(&mmu->mappings);
321 
322 	drm_mm_init(&mmu->mm, mmu->domain->base, mmu->domain->size);
323 
324 	return mmu;
325 }
326 
327 void etnaviv_iommu_restore(struct etnaviv_gpu *gpu)
328 {
329 	if (gpu->mmu->version == ETNAVIV_IOMMU_V1)
330 		etnaviv_iommuv1_restore(gpu);
331 	else
332 		etnaviv_iommuv2_restore(gpu);
333 }
334 
335 int etnaviv_iommu_get_suballoc_va(struct etnaviv_gpu *gpu, dma_addr_t paddr,
336 				  struct drm_mm_node *vram_node, size_t size,
337 				  u32 *iova)
338 {
339 	struct etnaviv_iommu *mmu = gpu->mmu;
340 
341 	if (mmu->version == ETNAVIV_IOMMU_V1) {
342 		*iova = paddr - gpu->memory_base;
343 		return 0;
344 	} else {
345 		int ret;
346 
347 		mutex_lock(&mmu->lock);
348 		ret = etnaviv_iommu_find_iova(mmu, vram_node, size);
349 		if (ret < 0) {
350 			mutex_unlock(&mmu->lock);
351 			return ret;
352 		}
353 		ret = etnaviv_domain_map(mmu->domain, vram_node->start, paddr,
354 					 size, ETNAVIV_PROT_READ);
355 		if (ret < 0) {
356 			drm_mm_remove_node(vram_node);
357 			mutex_unlock(&mmu->lock);
358 			return ret;
359 		}
360 		gpu->mmu->need_flush = true;
361 		mutex_unlock(&mmu->lock);
362 
363 		*iova = (u32)vram_node->start;
364 		return 0;
365 	}
366 }
367 
368 void etnaviv_iommu_put_suballoc_va(struct etnaviv_gpu *gpu,
369 				   struct drm_mm_node *vram_node, size_t size,
370 				   u32 iova)
371 {
372 	struct etnaviv_iommu *mmu = gpu->mmu;
373 
374 	if (mmu->version == ETNAVIV_IOMMU_V2) {
375 		mutex_lock(&mmu->lock);
376 		etnaviv_domain_unmap(mmu->domain, iova, size);
377 		drm_mm_remove_node(vram_node);
378 		mutex_unlock(&mmu->lock);
379 	}
380 }
381 size_t etnaviv_iommu_dump_size(struct etnaviv_iommu *iommu)
382 {
383 	return iommu->domain->ops->dump_size(iommu->domain);
384 }
385 
386 void etnaviv_iommu_dump(struct etnaviv_iommu *iommu, void *buf)
387 {
388 	iommu->domain->ops->dump(iommu->domain, buf);
389 }
390