1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
4  * Author:Mark Yao <mark.yao@rock-chips.com>
5  */
6 
7 #include <linux/dma-buf.h>
8 #include <linux/iommu.h>
9 #include <linux/vmalloc.h>
10 
11 #include <drm/drm.h>
12 #include <drm/drm_gem.h>
13 #include <drm/drm_gem_cma_helper.h>
14 #include <drm/drm_prime.h>
15 #include <drm/drm_vma_manager.h>
16 
17 #include "rockchip_drm_drv.h"
18 #include "rockchip_drm_gem.h"
19 
20 static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
21 {
22 	struct drm_device *drm = rk_obj->base.dev;
23 	struct rockchip_drm_private *private = drm->dev_private;
24 	int prot = IOMMU_READ | IOMMU_WRITE;
25 	ssize_t ret;
26 
27 	mutex_lock(&private->mm_lock);
28 	ret = drm_mm_insert_node_generic(&private->mm, &rk_obj->mm,
29 					 rk_obj->base.size, PAGE_SIZE,
30 					 0, 0);
31 	mutex_unlock(&private->mm_lock);
32 
33 	if (ret < 0) {
34 		DRM_ERROR("out of I/O virtual memory: %zd\n", ret);
35 		return ret;
36 	}
37 
38 	rk_obj->dma_addr = rk_obj->mm.start;
39 
40 	ret = iommu_map_sgtable(private->domain, rk_obj->dma_addr, rk_obj->sgt,
41 				prot);
42 	if (ret < rk_obj->base.size) {
43 		DRM_ERROR("failed to map buffer: size=%zd request_size=%zd\n",
44 			  ret, rk_obj->base.size);
45 		ret = -ENOMEM;
46 		goto err_remove_node;
47 	}
48 
49 	rk_obj->size = ret;
50 
51 	return 0;
52 
53 err_remove_node:
54 	mutex_lock(&private->mm_lock);
55 	drm_mm_remove_node(&rk_obj->mm);
56 	mutex_unlock(&private->mm_lock);
57 
58 	return ret;
59 }
60 
61 static int rockchip_gem_iommu_unmap(struct rockchip_gem_object *rk_obj)
62 {
63 	struct drm_device *drm = rk_obj->base.dev;
64 	struct rockchip_drm_private *private = drm->dev_private;
65 
66 	iommu_unmap(private->domain, rk_obj->dma_addr, rk_obj->size);
67 
68 	mutex_lock(&private->mm_lock);
69 
70 	drm_mm_remove_node(&rk_obj->mm);
71 
72 	mutex_unlock(&private->mm_lock);
73 
74 	return 0;
75 }
76 
77 static int rockchip_gem_get_pages(struct rockchip_gem_object *rk_obj)
78 {
79 	struct drm_device *drm = rk_obj->base.dev;
80 	int ret, i;
81 	struct scatterlist *s;
82 
83 	rk_obj->pages = drm_gem_get_pages(&rk_obj->base);
84 	if (IS_ERR(rk_obj->pages))
85 		return PTR_ERR(rk_obj->pages);
86 
87 	rk_obj->num_pages = rk_obj->base.size >> PAGE_SHIFT;
88 
89 	rk_obj->sgt = drm_prime_pages_to_sg(rk_obj->base.dev,
90 					    rk_obj->pages, rk_obj->num_pages);
91 	if (IS_ERR(rk_obj->sgt)) {
92 		ret = PTR_ERR(rk_obj->sgt);
93 		goto err_put_pages;
94 	}
95 
96 	/*
97 	 * Fake up the SG table so that dma_sync_sg_for_device() can be used
98 	 * to flush the pages associated with it.
99 	 *
100 	 * TODO: Replace this by drm_clflush_sg() once it can be implemented
101 	 * without relying on symbols that are not exported.
102 	 */
103 	for_each_sgtable_sg(rk_obj->sgt, s, i)
104 		sg_dma_address(s) = sg_phys(s);
105 
106 	dma_sync_sgtable_for_device(drm->dev, rk_obj->sgt, DMA_TO_DEVICE);
107 
108 	return 0;
109 
110 err_put_pages:
111 	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, false, false);
112 	return ret;
113 }
114 
115 static void rockchip_gem_put_pages(struct rockchip_gem_object *rk_obj)
116 {
117 	sg_free_table(rk_obj->sgt);
118 	kfree(rk_obj->sgt);
119 	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, true, true);
120 }
121 
122 static int rockchip_gem_alloc_iommu(struct rockchip_gem_object *rk_obj,
123 				    bool alloc_kmap)
124 {
125 	int ret;
126 
127 	ret = rockchip_gem_get_pages(rk_obj);
128 	if (ret < 0)
129 		return ret;
130 
131 	ret = rockchip_gem_iommu_map(rk_obj);
132 	if (ret < 0)
133 		goto err_free;
134 
135 	if (alloc_kmap) {
136 		rk_obj->kvaddr = vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
137 				      pgprot_writecombine(PAGE_KERNEL));
138 		if (!rk_obj->kvaddr) {
139 			DRM_ERROR("failed to vmap() buffer\n");
140 			ret = -ENOMEM;
141 			goto err_unmap;
142 		}
143 	}
144 
145 	return 0;
146 
147 err_unmap:
148 	rockchip_gem_iommu_unmap(rk_obj);
149 err_free:
150 	rockchip_gem_put_pages(rk_obj);
151 
152 	return ret;
153 }
154 
155 static int rockchip_gem_alloc_dma(struct rockchip_gem_object *rk_obj,
156 				  bool alloc_kmap)
157 {
158 	struct drm_gem_object *obj = &rk_obj->base;
159 	struct drm_device *drm = obj->dev;
160 
161 	rk_obj->dma_attrs = DMA_ATTR_WRITE_COMBINE;
162 
163 	if (!alloc_kmap)
164 		rk_obj->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
165 
166 	rk_obj->kvaddr = dma_alloc_attrs(drm->dev, obj->size,
167 					 &rk_obj->dma_addr, GFP_KERNEL,
168 					 rk_obj->dma_attrs);
169 	if (!rk_obj->kvaddr) {
170 		DRM_ERROR("failed to allocate %zu byte dma buffer", obj->size);
171 		return -ENOMEM;
172 	}
173 
174 	return 0;
175 }
176 
177 static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
178 				  bool alloc_kmap)
179 {
180 	struct drm_gem_object *obj = &rk_obj->base;
181 	struct drm_device *drm = obj->dev;
182 	struct rockchip_drm_private *private = drm->dev_private;
183 
184 	if (private->domain)
185 		return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
186 	else
187 		return rockchip_gem_alloc_dma(rk_obj, alloc_kmap);
188 }
189 
190 static void rockchip_gem_free_iommu(struct rockchip_gem_object *rk_obj)
191 {
192 	vunmap(rk_obj->kvaddr);
193 	rockchip_gem_iommu_unmap(rk_obj);
194 	rockchip_gem_put_pages(rk_obj);
195 }
196 
197 static void rockchip_gem_free_dma(struct rockchip_gem_object *rk_obj)
198 {
199 	struct drm_gem_object *obj = &rk_obj->base;
200 	struct drm_device *drm = obj->dev;
201 
202 	dma_free_attrs(drm->dev, obj->size, rk_obj->kvaddr, rk_obj->dma_addr,
203 		       rk_obj->dma_attrs);
204 }
205 
206 static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
207 {
208 	if (rk_obj->pages)
209 		rockchip_gem_free_iommu(rk_obj);
210 	else
211 		rockchip_gem_free_dma(rk_obj);
212 }
213 
214 static int rockchip_drm_gem_object_mmap_iommu(struct drm_gem_object *obj,
215 					      struct vm_area_struct *vma)
216 {
217 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
218 	unsigned int count = obj->size >> PAGE_SHIFT;
219 	unsigned long user_count = vma_pages(vma);
220 
221 	if (user_count == 0)
222 		return -ENXIO;
223 
224 	return vm_map_pages(vma, rk_obj->pages, count);
225 }
226 
227 static int rockchip_drm_gem_object_mmap_dma(struct drm_gem_object *obj,
228 					    struct vm_area_struct *vma)
229 {
230 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
231 	struct drm_device *drm = obj->dev;
232 
233 	return dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
234 			      obj->size, rk_obj->dma_attrs);
235 }
236 
237 static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
238 					struct vm_area_struct *vma)
239 {
240 	int ret;
241 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
242 
243 	/*
244 	 * We allocated a struct page table for rk_obj, so clear
245 	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
246 	 */
247 	vma->vm_flags &= ~VM_PFNMAP;
248 
249 	if (rk_obj->pages)
250 		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
251 	else
252 		ret = rockchip_drm_gem_object_mmap_dma(obj, vma);
253 
254 	if (ret)
255 		drm_gem_vm_close(vma);
256 
257 	return ret;
258 }
259 
260 int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
261 			  struct vm_area_struct *vma)
262 {
263 	int ret;
264 
265 	ret = drm_gem_mmap_obj(obj, obj->size, vma);
266 	if (ret)
267 		return ret;
268 
269 	return rockchip_drm_gem_object_mmap(obj, vma);
270 }
271 
272 /* drm driver mmap file operations */
273 int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
274 {
275 	struct drm_gem_object *obj;
276 	int ret;
277 
278 	ret = drm_gem_mmap(filp, vma);
279 	if (ret)
280 		return ret;
281 
282 	/*
283 	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
284 	 * whole buffer from the start.
285 	 */
286 	vma->vm_pgoff = 0;
287 
288 	obj = vma->vm_private_data;
289 
290 	return rockchip_drm_gem_object_mmap(obj, vma);
291 }
292 
293 static void rockchip_gem_release_object(struct rockchip_gem_object *rk_obj)
294 {
295 	drm_gem_object_release(&rk_obj->base);
296 	kfree(rk_obj);
297 }
298 
299 static const struct drm_gem_object_funcs rockchip_gem_object_funcs = {
300 	.free = rockchip_gem_free_object,
301 	.get_sg_table = rockchip_gem_prime_get_sg_table,
302 	.vmap = rockchip_gem_prime_vmap,
303 	.vunmap	= rockchip_gem_prime_vunmap,
304 	.vm_ops = &drm_gem_cma_vm_ops,
305 };
306 
307 static struct rockchip_gem_object *
308 	rockchip_gem_alloc_object(struct drm_device *drm, unsigned int size)
309 {
310 	struct rockchip_gem_object *rk_obj;
311 	struct drm_gem_object *obj;
312 
313 	size = round_up(size, PAGE_SIZE);
314 
315 	rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
316 	if (!rk_obj)
317 		return ERR_PTR(-ENOMEM);
318 
319 	obj = &rk_obj->base;
320 
321 	obj->funcs = &rockchip_gem_object_funcs;
322 
323 	drm_gem_object_init(drm, obj, size);
324 
325 	return rk_obj;
326 }
327 
328 struct rockchip_gem_object *
329 rockchip_gem_create_object(struct drm_device *drm, unsigned int size,
330 			   bool alloc_kmap)
331 {
332 	struct rockchip_gem_object *rk_obj;
333 	int ret;
334 
335 	rk_obj = rockchip_gem_alloc_object(drm, size);
336 	if (IS_ERR(rk_obj))
337 		return rk_obj;
338 
339 	ret = rockchip_gem_alloc_buf(rk_obj, alloc_kmap);
340 	if (ret)
341 		goto err_free_rk_obj;
342 
343 	return rk_obj;
344 
345 err_free_rk_obj:
346 	rockchip_gem_release_object(rk_obj);
347 	return ERR_PTR(ret);
348 }
349 
350 /*
351  * rockchip_gem_free_object - (struct drm_gem_object_funcs)->free
352  * callback function
353  */
354 void rockchip_gem_free_object(struct drm_gem_object *obj)
355 {
356 	struct drm_device *drm = obj->dev;
357 	struct rockchip_drm_private *private = drm->dev_private;
358 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
359 
360 	if (obj->import_attach) {
361 		if (private->domain) {
362 			rockchip_gem_iommu_unmap(rk_obj);
363 		} else {
364 			dma_unmap_sgtable(drm->dev, rk_obj->sgt,
365 					  DMA_BIDIRECTIONAL, 0);
366 		}
367 		drm_prime_gem_destroy(obj, rk_obj->sgt);
368 	} else {
369 		rockchip_gem_free_buf(rk_obj);
370 	}
371 
372 	rockchip_gem_release_object(rk_obj);
373 }
374 
375 /*
376  * rockchip_gem_create_with_handle - allocate an object with the given
377  * size and create a gem handle on it
378  *
379  * returns a struct rockchip_gem_object* on success or ERR_PTR values
380  * on failure.
381  */
382 static struct rockchip_gem_object *
383 rockchip_gem_create_with_handle(struct drm_file *file_priv,
384 				struct drm_device *drm, unsigned int size,
385 				unsigned int *handle)
386 {
387 	struct rockchip_gem_object *rk_obj;
388 	struct drm_gem_object *obj;
389 	int ret;
390 
391 	rk_obj = rockchip_gem_create_object(drm, size, false);
392 	if (IS_ERR(rk_obj))
393 		return ERR_CAST(rk_obj);
394 
395 	obj = &rk_obj->base;
396 
397 	/*
398 	 * allocate a id of idr table where the obj is registered
399 	 * and handle has the id what user can see.
400 	 */
401 	ret = drm_gem_handle_create(file_priv, obj, handle);
402 	if (ret)
403 		goto err_handle_create;
404 
405 	/* drop reference from allocate - handle holds it now. */
406 	drm_gem_object_put(obj);
407 
408 	return rk_obj;
409 
410 err_handle_create:
411 	rockchip_gem_free_object(obj);
412 
413 	return ERR_PTR(ret);
414 }
415 
416 /*
417  * rockchip_gem_dumb_create - (struct drm_driver)->dumb_create callback
418  * function
419  *
420  * This aligns the pitch and size arguments to the minimum required. wrap
421  * this into your own function if you need bigger alignment.
422  */
423 int rockchip_gem_dumb_create(struct drm_file *file_priv,
424 			     struct drm_device *dev,
425 			     struct drm_mode_create_dumb *args)
426 {
427 	struct rockchip_gem_object *rk_obj;
428 	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
429 
430 	/*
431 	 * align to 64 bytes since Mali requires it.
432 	 */
433 	args->pitch = ALIGN(min_pitch, 64);
434 	args->size = args->pitch * args->height;
435 
436 	rk_obj = rockchip_gem_create_with_handle(file_priv, dev, args->size,
437 						 &args->handle);
438 
439 	return PTR_ERR_OR_ZERO(rk_obj);
440 }
441 
442 /*
443  * Allocate a sg_table for this GEM object.
444  * Note: Both the table's contents, and the sg_table itself must be freed by
445  *       the caller.
446  * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
447  */
448 struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
449 {
450 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
451 	struct drm_device *drm = obj->dev;
452 	struct sg_table *sgt;
453 	int ret;
454 
455 	if (rk_obj->pages)
456 		return drm_prime_pages_to_sg(obj->dev, rk_obj->pages, rk_obj->num_pages);
457 
458 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
459 	if (!sgt)
460 		return ERR_PTR(-ENOMEM);
461 
462 	ret = dma_get_sgtable_attrs(drm->dev, sgt, rk_obj->kvaddr,
463 				    rk_obj->dma_addr, obj->size,
464 				    rk_obj->dma_attrs);
465 	if (ret) {
466 		DRM_ERROR("failed to allocate sgt, %d\n", ret);
467 		kfree(sgt);
468 		return ERR_PTR(ret);
469 	}
470 
471 	return sgt;
472 }
473 
474 static int
475 rockchip_gem_iommu_map_sg(struct drm_device *drm,
476 			  struct dma_buf_attachment *attach,
477 			  struct sg_table *sg,
478 			  struct rockchip_gem_object *rk_obj)
479 {
480 	rk_obj->sgt = sg;
481 	return rockchip_gem_iommu_map(rk_obj);
482 }
483 
484 static int
485 rockchip_gem_dma_map_sg(struct drm_device *drm,
486 			struct dma_buf_attachment *attach,
487 			struct sg_table *sg,
488 			struct rockchip_gem_object *rk_obj)
489 {
490 	int err = dma_map_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
491 	if (err)
492 		return err;
493 
494 	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
495 		DRM_ERROR("failed to map sg_table to contiguous linear address.\n");
496 		dma_unmap_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
497 		return -EINVAL;
498 	}
499 
500 	rk_obj->dma_addr = sg_dma_address(sg->sgl);
501 	rk_obj->sgt = sg;
502 	return 0;
503 }
504 
505 struct drm_gem_object *
506 rockchip_gem_prime_import_sg_table(struct drm_device *drm,
507 				   struct dma_buf_attachment *attach,
508 				   struct sg_table *sg)
509 {
510 	struct rockchip_drm_private *private = drm->dev_private;
511 	struct rockchip_gem_object *rk_obj;
512 	int ret;
513 
514 	rk_obj = rockchip_gem_alloc_object(drm, attach->dmabuf->size);
515 	if (IS_ERR(rk_obj))
516 		return ERR_CAST(rk_obj);
517 
518 	if (private->domain)
519 		ret = rockchip_gem_iommu_map_sg(drm, attach, sg, rk_obj);
520 	else
521 		ret = rockchip_gem_dma_map_sg(drm, attach, sg, rk_obj);
522 
523 	if (ret < 0) {
524 		DRM_ERROR("failed to import sg table: %d\n", ret);
525 		goto err_free_rk_obj;
526 	}
527 
528 	return &rk_obj->base;
529 
530 err_free_rk_obj:
531 	rockchip_gem_release_object(rk_obj);
532 	return ERR_PTR(ret);
533 }
534 
535 int rockchip_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
536 {
537 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
538 
539 	if (rk_obj->pages) {
540 		void *vaddr = vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
541 				  pgprot_writecombine(PAGE_KERNEL));
542 		if (!vaddr)
543 			return -ENOMEM;
544 		dma_buf_map_set_vaddr(map, vaddr);
545 		return 0;
546 	}
547 
548 	if (rk_obj->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING)
549 		return -ENOMEM;
550 	dma_buf_map_set_vaddr(map, rk_obj->kvaddr);
551 
552 	return 0;
553 }
554 
555 void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
556 {
557 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
558 
559 	if (rk_obj->pages) {
560 		vunmap(map->vaddr);
561 		return;
562 	}
563 
564 	/* Nothing to do if allocated by DMA mapping API. */
565 }
566