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