1 /* exynos_drm_gem.c
2  *
3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4  * Author: Inki Dae <inki.dae@samsung.com>
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  */
11 
12 #include <drm/drmP.h>
13 #include <drm/drm_vma_manager.h>
14 
15 #include <linux/shmem_fs.h>
16 #include <linux/dma-buf.h>
17 #include <linux/pfn_t.h>
18 #include <drm/exynos_drm.h>
19 
20 #include "exynos_drm_drv.h"
21 #include "exynos_drm_gem.h"
22 #include "exynos_drm_iommu.h"
23 
24 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)
25 {
26 	struct drm_device *dev = exynos_gem->base.dev;
27 	unsigned long attr;
28 	unsigned int nr_pages;
29 	struct sg_table sgt;
30 	int ret = -ENOMEM;
31 
32 	if (exynos_gem->dma_addr) {
33 		DRM_DEBUG_KMS("already allocated.\n");
34 		return 0;
35 	}
36 
37 	exynos_gem->dma_attrs = 0;
38 
39 	/*
40 	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
41 	 * region will be allocated else physically contiguous
42 	 * as possible.
43 	 */
44 	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
45 		exynos_gem->dma_attrs |= DMA_ATTR_FORCE_CONTIGUOUS;
46 
47 	/*
48 	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
49 	 * else cachable mapping.
50 	 */
51 	if (exynos_gem->flags & EXYNOS_BO_WC ||
52 			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
53 		attr = DMA_ATTR_WRITE_COMBINE;
54 	else
55 		attr = DMA_ATTR_NON_CONSISTENT;
56 
57 	exynos_gem->dma_attrs |= attr;
58 	exynos_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
59 
60 	nr_pages = exynos_gem->size >> PAGE_SHIFT;
61 
62 	exynos_gem->pages = drm_calloc_large(nr_pages, sizeof(struct page *));
63 	if (!exynos_gem->pages) {
64 		DRM_ERROR("failed to allocate pages.\n");
65 		return -ENOMEM;
66 	}
67 
68 	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
69 					     &exynos_gem->dma_addr, GFP_KERNEL,
70 					     exynos_gem->dma_attrs);
71 	if (!exynos_gem->cookie) {
72 		DRM_ERROR("failed to allocate buffer.\n");
73 		goto err_free;
74 	}
75 
76 	ret = dma_get_sgtable_attrs(to_dma_dev(dev), &sgt, exynos_gem->cookie,
77 				    exynos_gem->dma_addr, exynos_gem->size,
78 				    exynos_gem->dma_attrs);
79 	if (ret < 0) {
80 		DRM_ERROR("failed to get sgtable.\n");
81 		goto err_dma_free;
82 	}
83 
84 	if (drm_prime_sg_to_page_addr_arrays(&sgt, exynos_gem->pages, NULL,
85 					     nr_pages)) {
86 		DRM_ERROR("invalid sgtable.\n");
87 		ret = -EINVAL;
88 		goto err_sgt_free;
89 	}
90 
91 	sg_free_table(&sgt);
92 
93 	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
94 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
95 
96 	return 0;
97 
98 err_sgt_free:
99 	sg_free_table(&sgt);
100 err_dma_free:
101 	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
102 		       exynos_gem->dma_addr, exynos_gem->dma_attrs);
103 err_free:
104 	drm_free_large(exynos_gem->pages);
105 
106 	return ret;
107 }
108 
109 static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
110 {
111 	struct drm_device *dev = exynos_gem->base.dev;
112 
113 	if (!exynos_gem->dma_addr) {
114 		DRM_DEBUG_KMS("dma_addr is invalid.\n");
115 		return;
116 	}
117 
118 	DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n",
119 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
120 
121 	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
122 			(dma_addr_t)exynos_gem->dma_addr,
123 			exynos_gem->dma_attrs);
124 
125 	drm_free_large(exynos_gem->pages);
126 }
127 
128 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
129 					struct drm_file *file_priv,
130 					unsigned int *handle)
131 {
132 	int ret;
133 
134 	/*
135 	 * allocate a id of idr table where the obj is registered
136 	 * and handle has the id what user can see.
137 	 */
138 	ret = drm_gem_handle_create(file_priv, obj, handle);
139 	if (ret)
140 		return ret;
141 
142 	DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);
143 
144 	/* drop reference from allocate - handle holds it now. */
145 	drm_gem_object_unreference_unlocked(obj);
146 
147 	return 0;
148 }
149 
150 void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
151 {
152 	struct drm_gem_object *obj = &exynos_gem->base;
153 
154 	DRM_DEBUG_KMS("handle count = %d\n", obj->handle_count);
155 
156 	/*
157 	 * do not release memory region from exporter.
158 	 *
159 	 * the region will be released by exporter
160 	 * once dmabuf's refcount becomes 0.
161 	 */
162 	if (obj->import_attach)
163 		drm_prime_gem_destroy(obj, exynos_gem->sgt);
164 	else
165 		exynos_drm_free_buf(exynos_gem);
166 
167 	/* release file pointer to gem object. */
168 	drm_gem_object_release(obj);
169 
170 	kfree(exynos_gem);
171 }
172 
173 unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
174 						unsigned int gem_handle,
175 						struct drm_file *file_priv)
176 {
177 	struct exynos_drm_gem *exynos_gem;
178 	struct drm_gem_object *obj;
179 
180 	obj = drm_gem_object_lookup(file_priv, gem_handle);
181 	if (!obj) {
182 		DRM_ERROR("failed to lookup gem object.\n");
183 		return 0;
184 	}
185 
186 	exynos_gem = to_exynos_gem(obj);
187 
188 	drm_gem_object_unreference_unlocked(obj);
189 
190 	return exynos_gem->size;
191 }
192 
193 static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
194 						  unsigned long size)
195 {
196 	struct exynos_drm_gem *exynos_gem;
197 	struct drm_gem_object *obj;
198 	int ret;
199 
200 	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
201 	if (!exynos_gem)
202 		return ERR_PTR(-ENOMEM);
203 
204 	exynos_gem->size = size;
205 	obj = &exynos_gem->base;
206 
207 	ret = drm_gem_object_init(dev, obj, size);
208 	if (ret < 0) {
209 		DRM_ERROR("failed to initialize gem object\n");
210 		kfree(exynos_gem);
211 		return ERR_PTR(ret);
212 	}
213 
214 	ret = drm_gem_create_mmap_offset(obj);
215 	if (ret < 0) {
216 		drm_gem_object_release(obj);
217 		kfree(exynos_gem);
218 		return ERR_PTR(ret);
219 	}
220 
221 	DRM_DEBUG_KMS("created file object = %p\n", obj->filp);
222 
223 	return exynos_gem;
224 }
225 
226 struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
227 					     unsigned int flags,
228 					     unsigned long size)
229 {
230 	struct exynos_drm_gem *exynos_gem;
231 	int ret;
232 
233 	if (flags & ~(EXYNOS_BO_MASK)) {
234 		DRM_ERROR("invalid flags.\n");
235 		return ERR_PTR(-EINVAL);
236 	}
237 
238 	if (!size) {
239 		DRM_ERROR("invalid size.\n");
240 		return ERR_PTR(-EINVAL);
241 	}
242 
243 	size = roundup(size, PAGE_SIZE);
244 
245 	exynos_gem = exynos_drm_gem_init(dev, size);
246 	if (IS_ERR(exynos_gem))
247 		return exynos_gem;
248 
249 	/* set memory type and cache attribute from user side. */
250 	exynos_gem->flags = flags;
251 
252 	ret = exynos_drm_alloc_buf(exynos_gem);
253 	if (ret < 0) {
254 		drm_gem_object_release(&exynos_gem->base);
255 		kfree(exynos_gem);
256 		return ERR_PTR(ret);
257 	}
258 
259 	return exynos_gem;
260 }
261 
262 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
263 				struct drm_file *file_priv)
264 {
265 	struct drm_exynos_gem_create *args = data;
266 	struct exynos_drm_gem *exynos_gem;
267 	int ret;
268 
269 	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size);
270 	if (IS_ERR(exynos_gem))
271 		return PTR_ERR(exynos_gem);
272 
273 	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
274 					   &args->handle);
275 	if (ret) {
276 		exynos_drm_gem_destroy(exynos_gem);
277 		return ret;
278 	}
279 
280 	return 0;
281 }
282 
283 int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
284 			     struct drm_file *file_priv)
285 {
286 	struct drm_exynos_gem_map *args = data;
287 
288 	return exynos_drm_gem_dumb_map_offset(file_priv, dev, args->handle,
289 					      &args->offset);
290 }
291 
292 dma_addr_t *exynos_drm_gem_get_dma_addr(struct drm_device *dev,
293 					unsigned int gem_handle,
294 					struct drm_file *filp)
295 {
296 	struct exynos_drm_gem *exynos_gem;
297 	struct drm_gem_object *obj;
298 
299 	obj = drm_gem_object_lookup(filp, gem_handle);
300 	if (!obj) {
301 		DRM_ERROR("failed to lookup gem object.\n");
302 		return ERR_PTR(-EINVAL);
303 	}
304 
305 	exynos_gem = to_exynos_gem(obj);
306 
307 	return &exynos_gem->dma_addr;
308 }
309 
310 void exynos_drm_gem_put_dma_addr(struct drm_device *dev,
311 					unsigned int gem_handle,
312 					struct drm_file *filp)
313 {
314 	struct drm_gem_object *obj;
315 
316 	obj = drm_gem_object_lookup(filp, gem_handle);
317 	if (!obj) {
318 		DRM_ERROR("failed to lookup gem object.\n");
319 		return;
320 	}
321 
322 	drm_gem_object_unreference_unlocked(obj);
323 
324 	/*
325 	 * decrease obj->refcount one more time because we has already
326 	 * increased it at exynos_drm_gem_get_dma_addr().
327 	 */
328 	drm_gem_object_unreference_unlocked(obj);
329 }
330 
331 static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
332 				      struct vm_area_struct *vma)
333 {
334 	struct drm_device *drm_dev = exynos_gem->base.dev;
335 	unsigned long vm_size;
336 	int ret;
337 
338 	vma->vm_flags &= ~VM_PFNMAP;
339 	vma->vm_pgoff = 0;
340 
341 	vm_size = vma->vm_end - vma->vm_start;
342 
343 	/* check if user-requested size is valid. */
344 	if (vm_size > exynos_gem->size)
345 		return -EINVAL;
346 
347 	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
348 			     exynos_gem->dma_addr, exynos_gem->size,
349 			     exynos_gem->dma_attrs);
350 	if (ret < 0) {
351 		DRM_ERROR("failed to mmap.\n");
352 		return ret;
353 	}
354 
355 	return 0;
356 }
357 
358 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
359 				      struct drm_file *file_priv)
360 {
361 	struct exynos_drm_gem *exynos_gem;
362 	struct drm_exynos_gem_info *args = data;
363 	struct drm_gem_object *obj;
364 
365 	obj = drm_gem_object_lookup(file_priv, args->handle);
366 	if (!obj) {
367 		DRM_ERROR("failed to lookup gem object.\n");
368 		return -EINVAL;
369 	}
370 
371 	exynos_gem = to_exynos_gem(obj);
372 
373 	args->flags = exynos_gem->flags;
374 	args->size = exynos_gem->size;
375 
376 	drm_gem_object_unreference_unlocked(obj);
377 
378 	return 0;
379 }
380 
381 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
382 {
383 	exynos_drm_gem_destroy(to_exynos_gem(obj));
384 }
385 
386 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
387 			       struct drm_device *dev,
388 			       struct drm_mode_create_dumb *args)
389 {
390 	struct exynos_drm_gem *exynos_gem;
391 	unsigned int flags;
392 	int ret;
393 
394 	/*
395 	 * allocate memory to be used for framebuffer.
396 	 * - this callback would be called by user application
397 	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
398 	 */
399 
400 	args->pitch = args->width * ((args->bpp + 7) / 8);
401 	args->size = args->pitch * args->height;
402 
403 	if (is_drm_iommu_supported(dev))
404 		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
405 	else
406 		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
407 
408 	exynos_gem = exynos_drm_gem_create(dev, flags, args->size);
409 	if (IS_ERR(exynos_gem)) {
410 		dev_warn(dev->dev, "FB allocation failed.\n");
411 		return PTR_ERR(exynos_gem);
412 	}
413 
414 	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
415 					   &args->handle);
416 	if (ret) {
417 		exynos_drm_gem_destroy(exynos_gem);
418 		return ret;
419 	}
420 
421 	return 0;
422 }
423 
424 int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
425 				   struct drm_device *dev, uint32_t handle,
426 				   uint64_t *offset)
427 {
428 	struct drm_gem_object *obj;
429 	int ret = 0;
430 
431 	/*
432 	 * get offset of memory allocated for drm framebuffer.
433 	 * - this callback would be called by user application
434 	 *	with DRM_IOCTL_MODE_MAP_DUMB command.
435 	 */
436 
437 	obj = drm_gem_object_lookup(file_priv, handle);
438 	if (!obj) {
439 		DRM_ERROR("failed to lookup gem object.\n");
440 		return -EINVAL;
441 	}
442 
443 	*offset = drm_vma_node_offset_addr(&obj->vma_node);
444 	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);
445 
446 	drm_gem_object_unreference_unlocked(obj);
447 	return ret;
448 }
449 
450 int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
451 {
452 	struct drm_gem_object *obj = vma->vm_private_data;
453 	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
454 	unsigned long pfn;
455 	pgoff_t page_offset;
456 	int ret;
457 
458 	page_offset = ((unsigned long)vmf->virtual_address -
459 			vma->vm_start) >> PAGE_SHIFT;
460 
461 	if (page_offset >= (exynos_gem->size >> PAGE_SHIFT)) {
462 		DRM_ERROR("invalid page offset\n");
463 		ret = -EINVAL;
464 		goto out;
465 	}
466 
467 	pfn = page_to_pfn(exynos_gem->pages[page_offset]);
468 	ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
469 			__pfn_to_pfn_t(pfn, PFN_DEV));
470 
471 out:
472 	switch (ret) {
473 	case 0:
474 	case -ERESTARTSYS:
475 	case -EINTR:
476 		return VM_FAULT_NOPAGE;
477 	case -ENOMEM:
478 		return VM_FAULT_OOM;
479 	default:
480 		return VM_FAULT_SIGBUS;
481 	}
482 }
483 
484 static int exynos_drm_gem_mmap_obj(struct drm_gem_object *obj,
485 				   struct vm_area_struct *vma)
486 {
487 	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
488 	int ret;
489 
490 	DRM_DEBUG_KMS("flags = 0x%x\n", exynos_gem->flags);
491 
492 	/* non-cachable as default. */
493 	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
494 		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
495 	else if (exynos_gem->flags & EXYNOS_BO_WC)
496 		vma->vm_page_prot =
497 			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
498 	else
499 		vma->vm_page_prot =
500 			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
501 
502 	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
503 	if (ret)
504 		goto err_close_vm;
505 
506 	return ret;
507 
508 err_close_vm:
509 	drm_gem_vm_close(vma);
510 
511 	return ret;
512 }
513 
514 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
515 {
516 	struct drm_gem_object *obj;
517 	int ret;
518 
519 	/* set vm_area_struct. */
520 	ret = drm_gem_mmap(filp, vma);
521 	if (ret < 0) {
522 		DRM_ERROR("failed to mmap.\n");
523 		return ret;
524 	}
525 
526 	obj = vma->vm_private_data;
527 
528 	if (obj->import_attach)
529 		return dma_buf_mmap(obj->dma_buf, vma, 0);
530 
531 	return exynos_drm_gem_mmap_obj(obj, vma);
532 }
533 
534 /* low-level interface prime helpers */
535 struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
536 {
537 	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
538 	int npages;
539 
540 	npages = exynos_gem->size >> PAGE_SHIFT;
541 
542 	return drm_prime_pages_to_sg(exynos_gem->pages, npages);
543 }
544 
545 struct drm_gem_object *
546 exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
547 				     struct dma_buf_attachment *attach,
548 				     struct sg_table *sgt)
549 {
550 	struct exynos_drm_gem *exynos_gem;
551 	int npages;
552 	int ret;
553 
554 	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
555 	if (IS_ERR(exynos_gem)) {
556 		ret = PTR_ERR(exynos_gem);
557 		return ERR_PTR(ret);
558 	}
559 
560 	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
561 
562 	npages = exynos_gem->size >> PAGE_SHIFT;
563 	exynos_gem->pages = drm_malloc_ab(npages, sizeof(struct page *));
564 	if (!exynos_gem->pages) {
565 		ret = -ENOMEM;
566 		goto err;
567 	}
568 
569 	ret = drm_prime_sg_to_page_addr_arrays(sgt, exynos_gem->pages, NULL,
570 					       npages);
571 	if (ret < 0)
572 		goto err_free_large;
573 
574 	exynos_gem->sgt = sgt;
575 
576 	if (sgt->nents == 1) {
577 		/* always physically continuous memory if sgt->nents is 1. */
578 		exynos_gem->flags |= EXYNOS_BO_CONTIG;
579 	} else {
580 		/*
581 		 * this case could be CONTIG or NONCONTIG type but for now
582 		 * sets NONCONTIG.
583 		 * TODO. we have to find a way that exporter can notify
584 		 * the type of its own buffer to importer.
585 		 */
586 		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
587 	}
588 
589 	return &exynos_gem->base;
590 
591 err_free_large:
592 	drm_free_large(exynos_gem->pages);
593 err:
594 	drm_gem_object_release(&exynos_gem->base);
595 	kfree(exynos_gem);
596 	return ERR_PTR(ret);
597 }
598 
599 void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj)
600 {
601 	return NULL;
602 }
603 
604 void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
605 {
606 	/* Nothing to do */
607 }
608 
609 int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
610 			      struct vm_area_struct *vma)
611 {
612 	int ret;
613 
614 	ret = drm_gem_mmap_obj(obj, obj->size, vma);
615 	if (ret < 0)
616 		return ret;
617 
618 	return exynos_drm_gem_mmap_obj(obj, vma);
619 }
620