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