1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* exynos_drm_gem.c
3  *
4  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
5  * Author: Inki Dae <inki.dae@samsung.com>
6  */
7 
8 
9 #include <linux/dma-buf.h>
10 #include <linux/pfn_t.h>
11 #include <linux/shmem_fs.h>
12 
13 #include <drm/drm_prime.h>
14 #include <drm/drm_vma_manager.h>
15 #include <drm/exynos_drm.h>
16 
17 #include "exynos_drm_drv.h"
18 #include "exynos_drm_gem.h"
19 
20 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
21 {
22 	struct drm_device *dev = exynos_gem->base.dev;
23 	unsigned long attr = 0;
24 
25 	if (exynos_gem->dma_addr) {
26 		DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
27 		return 0;
28 	}
29 
30 	/*
31 	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
32 	 * region will be allocated else physically contiguous
33 	 * as possible.
34 	 */
35 	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
36 		attr |= DMA_ATTR_FORCE_CONTIGUOUS;
37 
38 	/*
39 	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
40 	 * else cachable mapping.
41 	 */
42 	if (exynos_gem->flags & EXYNOS_BO_WC ||
43 			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
44 		attr |= DMA_ATTR_WRITE_COMBINE;
45 	else
46 		attr |= DMA_ATTR_NON_CONSISTENT;
47 
48 	/* FBDev emulation requires kernel mapping */
49 	if (!kvmap)
50 		attr |= DMA_ATTR_NO_KERNEL_MAPPING;
51 
52 	exynos_gem->dma_attrs = attr;
53 	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
54 					     &exynos_gem->dma_addr, GFP_KERNEL,
55 					     exynos_gem->dma_attrs);
56 	if (!exynos_gem->cookie) {
57 		DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
58 		return -ENOMEM;
59 	}
60 
61 	if (kvmap)
62 		exynos_gem->kvaddr = exynos_gem->cookie;
63 
64 	DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
65 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
66 	return 0;
67 }
68 
69 static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
70 {
71 	struct drm_device *dev = exynos_gem->base.dev;
72 
73 	if (!exynos_gem->dma_addr) {
74 		DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
75 		return;
76 	}
77 
78 	DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
79 			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
80 
81 	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
82 			(dma_addr_t)exynos_gem->dma_addr,
83 			exynos_gem->dma_attrs);
84 }
85 
86 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
87 					struct drm_file *file_priv,
88 					unsigned int *handle)
89 {
90 	int ret;
91 
92 	/*
93 	 * allocate a id of idr table where the obj is registered
94 	 * and handle has the id what user can see.
95 	 */
96 	ret = drm_gem_handle_create(file_priv, obj, handle);
97 	if (ret)
98 		return ret;
99 
100 	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
101 
102 	/* drop reference from allocate - handle holds it now. */
103 	drm_gem_object_put(obj);
104 
105 	return 0;
106 }
107 
108 void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
109 {
110 	struct drm_gem_object *obj = &exynos_gem->base;
111 
112 	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
113 			  obj->handle_count);
114 
115 	/*
116 	 * do not release memory region from exporter.
117 	 *
118 	 * the region will be released by exporter
119 	 * once dmabuf's refcount becomes 0.
120 	 */
121 	if (obj->import_attach)
122 		drm_prime_gem_destroy(obj, exynos_gem->sgt);
123 	else
124 		exynos_drm_free_buf(exynos_gem);
125 
126 	/* release file pointer to gem object. */
127 	drm_gem_object_release(obj);
128 
129 	kfree(exynos_gem);
130 }
131 
132 static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
133 						  unsigned long size)
134 {
135 	struct exynos_drm_gem *exynos_gem;
136 	struct drm_gem_object *obj;
137 	int ret;
138 
139 	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
140 	if (!exynos_gem)
141 		return ERR_PTR(-ENOMEM);
142 
143 	exynos_gem->size = size;
144 	obj = &exynos_gem->base;
145 
146 	ret = drm_gem_object_init(dev, obj, size);
147 	if (ret < 0) {
148 		DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
149 		kfree(exynos_gem);
150 		return ERR_PTR(ret);
151 	}
152 
153 	ret = drm_gem_create_mmap_offset(obj);
154 	if (ret < 0) {
155 		drm_gem_object_release(obj);
156 		kfree(exynos_gem);
157 		return ERR_PTR(ret);
158 	}
159 
160 	DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %pK\n", obj->filp);
161 
162 	return exynos_gem;
163 }
164 
165 struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
166 					     unsigned int flags,
167 					     unsigned long size,
168 					     bool kvmap)
169 {
170 	struct exynos_drm_gem *exynos_gem;
171 	int ret;
172 
173 	if (flags & ~(EXYNOS_BO_MASK)) {
174 		DRM_DEV_ERROR(dev->dev,
175 			      "invalid GEM buffer flags: %u\n", flags);
176 		return ERR_PTR(-EINVAL);
177 	}
178 
179 	if (!size) {
180 		DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
181 		return ERR_PTR(-EINVAL);
182 	}
183 
184 	size = roundup(size, PAGE_SIZE);
185 
186 	exynos_gem = exynos_drm_gem_init(dev, size);
187 	if (IS_ERR(exynos_gem))
188 		return exynos_gem;
189 
190 	if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
191 		/*
192 		 * when no IOMMU is available, all allocated buffers are
193 		 * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
194 		 */
195 		flags &= ~EXYNOS_BO_NONCONTIG;
196 		DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
197 	}
198 
199 	/* set memory type and cache attribute from user side. */
200 	exynos_gem->flags = flags;
201 
202 	ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
203 	if (ret < 0) {
204 		drm_gem_object_release(&exynos_gem->base);
205 		kfree(exynos_gem);
206 		return ERR_PTR(ret);
207 	}
208 
209 	return exynos_gem;
210 }
211 
212 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
213 				struct drm_file *file_priv)
214 {
215 	struct drm_exynos_gem_create *args = data;
216 	struct exynos_drm_gem *exynos_gem;
217 	int ret;
218 
219 	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
220 	if (IS_ERR(exynos_gem))
221 		return PTR_ERR(exynos_gem);
222 
223 	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
224 					   &args->handle);
225 	if (ret) {
226 		exynos_drm_gem_destroy(exynos_gem);
227 		return ret;
228 	}
229 
230 	return 0;
231 }
232 
233 int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
234 			     struct drm_file *file_priv)
235 {
236 	struct drm_exynos_gem_map *args = data;
237 
238 	return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
239 				       &args->offset);
240 }
241 
242 struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
243 					  unsigned int gem_handle)
244 {
245 	struct drm_gem_object *obj;
246 
247 	obj = drm_gem_object_lookup(filp, gem_handle);
248 	if (!obj)
249 		return NULL;
250 	return to_exynos_gem(obj);
251 }
252 
253 static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
254 				      struct vm_area_struct *vma)
255 {
256 	struct drm_device *drm_dev = exynos_gem->base.dev;
257 	unsigned long vm_size;
258 	int ret;
259 
260 	vma->vm_flags &= ~VM_PFNMAP;
261 	vma->vm_pgoff = 0;
262 
263 	vm_size = vma->vm_end - vma->vm_start;
264 
265 	/* check if user-requested size is valid. */
266 	if (vm_size > exynos_gem->size)
267 		return -EINVAL;
268 
269 	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
270 			     exynos_gem->dma_addr, exynos_gem->size,
271 			     exynos_gem->dma_attrs);
272 	if (ret < 0) {
273 		DRM_ERROR("failed to mmap.\n");
274 		return ret;
275 	}
276 
277 	return 0;
278 }
279 
280 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
281 				      struct drm_file *file_priv)
282 {
283 	struct exynos_drm_gem *exynos_gem;
284 	struct drm_exynos_gem_info *args = data;
285 	struct drm_gem_object *obj;
286 
287 	obj = drm_gem_object_lookup(file_priv, args->handle);
288 	if (!obj) {
289 		DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
290 		return -EINVAL;
291 	}
292 
293 	exynos_gem = to_exynos_gem(obj);
294 
295 	args->flags = exynos_gem->flags;
296 	args->size = exynos_gem->size;
297 
298 	drm_gem_object_put(obj);
299 
300 	return 0;
301 }
302 
303 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
304 {
305 	exynos_drm_gem_destroy(to_exynos_gem(obj));
306 }
307 
308 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
309 			       struct drm_device *dev,
310 			       struct drm_mode_create_dumb *args)
311 {
312 	struct exynos_drm_gem *exynos_gem;
313 	unsigned int flags;
314 	int ret;
315 
316 	/*
317 	 * allocate memory to be used for framebuffer.
318 	 * - this callback would be called by user application
319 	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
320 	 */
321 
322 	args->pitch = args->width * ((args->bpp + 7) / 8);
323 	args->size = args->pitch * args->height;
324 
325 	if (is_drm_iommu_supported(dev))
326 		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
327 	else
328 		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
329 
330 	exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
331 	if (IS_ERR(exynos_gem)) {
332 		dev_warn(dev->dev, "FB allocation failed.\n");
333 		return PTR_ERR(exynos_gem);
334 	}
335 
336 	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
337 					   &args->handle);
338 	if (ret) {
339 		exynos_drm_gem_destroy(exynos_gem);
340 		return ret;
341 	}
342 
343 	return 0;
344 }
345 
346 static int exynos_drm_gem_mmap_obj(struct drm_gem_object *obj,
347 				   struct vm_area_struct *vma)
348 {
349 	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
350 	int ret;
351 
352 	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
353 			  exynos_gem->flags);
354 
355 	/* non-cachable as default. */
356 	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
357 		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
358 	else if (exynos_gem->flags & EXYNOS_BO_WC)
359 		vma->vm_page_prot =
360 			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
361 	else
362 		vma->vm_page_prot =
363 			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
364 
365 	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
366 	if (ret)
367 		goto err_close_vm;
368 
369 	return ret;
370 
371 err_close_vm:
372 	drm_gem_vm_close(vma);
373 
374 	return ret;
375 }
376 
377 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
378 {
379 	struct drm_gem_object *obj;
380 	int ret;
381 
382 	/* set vm_area_struct. */
383 	ret = drm_gem_mmap(filp, vma);
384 	if (ret < 0) {
385 		DRM_ERROR("failed to mmap.\n");
386 		return ret;
387 	}
388 
389 	obj = vma->vm_private_data;
390 
391 	if (obj->import_attach)
392 		return dma_buf_mmap(obj->dma_buf, vma, 0);
393 
394 	return exynos_drm_gem_mmap_obj(obj, vma);
395 }
396 
397 /* low-level interface prime helpers */
398 struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
399 					    struct dma_buf *dma_buf)
400 {
401 	return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
402 }
403 
404 struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
405 {
406 	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
407 	struct drm_device *drm_dev = obj->dev;
408 	struct sg_table *sgt;
409 	int ret;
410 
411 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
412 	if (!sgt)
413 		return ERR_PTR(-ENOMEM);
414 
415 	ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
416 				    exynos_gem->dma_addr, exynos_gem->size,
417 				    exynos_gem->dma_attrs);
418 	if (ret) {
419 		DRM_ERROR("failed to get sgtable, %d\n", ret);
420 		kfree(sgt);
421 		return ERR_PTR(ret);
422 	}
423 
424 	return sgt;
425 }
426 
427 struct drm_gem_object *
428 exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
429 				     struct dma_buf_attachment *attach,
430 				     struct sg_table *sgt)
431 {
432 	struct exynos_drm_gem *exynos_gem;
433 
434 	if (sgt->nents < 1)
435 		return ERR_PTR(-EINVAL);
436 
437 	/*
438 	 * Check if the provided buffer has been mapped as contiguous
439 	 * into DMA address space.
440 	 */
441 	if (sgt->nents > 1) {
442 		dma_addr_t next_addr = sg_dma_address(sgt->sgl);
443 		struct scatterlist *s;
444 		unsigned int i;
445 
446 		for_each_sg(sgt->sgl, s, sgt->nents, i) {
447 			if (!sg_dma_len(s))
448 				break;
449 			if (sg_dma_address(s) != next_addr) {
450 				DRM_ERROR("buffer chunks must be mapped contiguously");
451 				return ERR_PTR(-EINVAL);
452 			}
453 			next_addr = sg_dma_address(s) + sg_dma_len(s);
454 		}
455 	}
456 
457 	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
458 	if (IS_ERR(exynos_gem))
459 		return ERR_CAST(exynos_gem);
460 
461 	/*
462 	 * Buffer has been mapped as contiguous into DMA address space,
463 	 * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
464 	 * We assume a simplified logic below:
465 	 */
466 	if (is_drm_iommu_supported(dev))
467 		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
468 	else
469 		exynos_gem->flags |= EXYNOS_BO_CONTIG;
470 
471 	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
472 	exynos_gem->sgt = sgt;
473 	return &exynos_gem->base;
474 }
475 
476 void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj)
477 {
478 	return NULL;
479 }
480 
481 void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
482 {
483 	/* Nothing to do */
484 }
485 
486 int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
487 			      struct vm_area_struct *vma)
488 {
489 	int ret;
490 
491 	ret = drm_gem_mmap_obj(obj, obj->size, vma);
492 	if (ret < 0)
493 		return ret;
494 
495 	return exynos_drm_gem_mmap_obj(obj, vma);
496 }
497