1 /*
2  * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
3  * Author:Mark Yao <mark.yao@rock-chips.com>
4  *
5  * This software is licensed under the terms of the GNU General Public
6  * License version 2, as published by the Free Software Foundation, and
7  * may be copied, distributed, and modified under those terms.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <drm/drm.h>
16 #include <drm/drmP.h>
17 #include <drm/drm_gem.h>
18 #include <drm/drm_vma_manager.h>
19 #include <linux/iommu.h>
20 
21 #include "rockchip_drm_drv.h"
22 #include "rockchip_drm_gem.h"
23 
24 static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
25 {
26 	struct drm_device *drm = rk_obj->base.dev;
27 	struct rockchip_drm_private *private = drm->dev_private;
28 	int prot = IOMMU_READ | IOMMU_WRITE;
29 	ssize_t ret;
30 
31 	mutex_lock(&private->mm_lock);
32 
33 	ret = drm_mm_insert_node_generic(&private->mm, &rk_obj->mm,
34 					 rk_obj->base.size, PAGE_SIZE,
35 					 0, 0);
36 
37 	mutex_unlock(&private->mm_lock);
38 	if (ret < 0) {
39 		DRM_ERROR("out of I/O virtual memory: %zd\n", ret);
40 		return ret;
41 	}
42 
43 	rk_obj->dma_addr = rk_obj->mm.start;
44 
45 	ret = iommu_map_sg(private->domain, rk_obj->dma_addr, rk_obj->sgt->sgl,
46 			   rk_obj->sgt->nents, prot);
47 	if (ret < rk_obj->base.size) {
48 		DRM_ERROR("failed to map buffer: size=%zd request_size=%zd\n",
49 			  ret, rk_obj->base.size);
50 		ret = -ENOMEM;
51 		goto err_remove_node;
52 	}
53 
54 	rk_obj->size = ret;
55 
56 	return 0;
57 
58 err_remove_node:
59 	drm_mm_remove_node(&rk_obj->mm);
60 
61 	return ret;
62 }
63 
64 static int rockchip_gem_iommu_unmap(struct rockchip_gem_object *rk_obj)
65 {
66 	struct drm_device *drm = rk_obj->base.dev;
67 	struct rockchip_drm_private *private = drm->dev_private;
68 
69 	iommu_unmap(private->domain, rk_obj->dma_addr, rk_obj->size);
70 
71 	mutex_lock(&private->mm_lock);
72 
73 	drm_mm_remove_node(&rk_obj->mm);
74 
75 	mutex_unlock(&private->mm_lock);
76 
77 	return 0;
78 }
79 
80 static int rockchip_gem_get_pages(struct rockchip_gem_object *rk_obj)
81 {
82 	struct drm_device *drm = rk_obj->base.dev;
83 	int ret, i;
84 	struct scatterlist *s;
85 
86 	rk_obj->pages = drm_gem_get_pages(&rk_obj->base);
87 	if (IS_ERR(rk_obj->pages))
88 		return PTR_ERR(rk_obj->pages);
89 
90 	rk_obj->num_pages = rk_obj->base.size >> PAGE_SHIFT;
91 
92 	rk_obj->sgt = drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
93 	if (IS_ERR(rk_obj->sgt)) {
94 		ret = PTR_ERR(rk_obj->sgt);
95 		goto err_put_pages;
96 	}
97 
98 	/*
99 	 * Fake up the SG table so that dma_sync_sg_for_device() can be used
100 	 * to flush the pages associated with it.
101 	 *
102 	 * TODO: Replace this by drm_clflush_sg() once it can be implemented
103 	 * without relying on symbols that are not exported.
104 	 */
105 	for_each_sg(rk_obj->sgt->sgl, s, rk_obj->sgt->nents, i)
106 		sg_dma_address(s) = sg_phys(s);
107 
108 	dma_sync_sg_for_device(drm->dev, rk_obj->sgt->sgl, rk_obj->sgt->nents,
109 			       DMA_TO_DEVICE);
110 
111 	return 0;
112 
113 err_put_pages:
114 	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, false, false);
115 	return ret;
116 }
117 
118 static void rockchip_gem_put_pages(struct rockchip_gem_object *rk_obj)
119 {
120 	sg_free_table(rk_obj->sgt);
121 	kfree(rk_obj->sgt);
122 	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, true, true);
123 }
124 
125 static int rockchip_gem_alloc_iommu(struct rockchip_gem_object *rk_obj,
126 				    bool alloc_kmap)
127 {
128 	int ret;
129 
130 	ret = rockchip_gem_get_pages(rk_obj);
131 	if (ret < 0)
132 		return ret;
133 
134 	ret = rockchip_gem_iommu_map(rk_obj);
135 	if (ret < 0)
136 		goto err_free;
137 
138 	if (alloc_kmap) {
139 		rk_obj->kvaddr = vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
140 				      pgprot_writecombine(PAGE_KERNEL));
141 		if (!rk_obj->kvaddr) {
142 			DRM_ERROR("failed to vmap() buffer\n");
143 			ret = -ENOMEM;
144 			goto err_unmap;
145 		}
146 	}
147 
148 	return 0;
149 
150 err_unmap:
151 	rockchip_gem_iommu_unmap(rk_obj);
152 err_free:
153 	rockchip_gem_put_pages(rk_obj);
154 
155 	return ret;
156 }
157 
158 static int rockchip_gem_alloc_dma(struct rockchip_gem_object *rk_obj,
159 				  bool alloc_kmap)
160 {
161 	struct drm_gem_object *obj = &rk_obj->base;
162 	struct drm_device *drm = obj->dev;
163 
164 	rk_obj->dma_attrs = DMA_ATTR_WRITE_COMBINE;
165 
166 	if (!alloc_kmap)
167 		rk_obj->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
168 
169 	rk_obj->kvaddr = dma_alloc_attrs(drm->dev, obj->size,
170 					 &rk_obj->dma_addr, GFP_KERNEL,
171 					 rk_obj->dma_attrs);
172 	if (!rk_obj->kvaddr) {
173 		DRM_ERROR("failed to allocate %zu byte dma buffer", obj->size);
174 		return -ENOMEM;
175 	}
176 
177 	return 0;
178 }
179 
180 static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
181 				  bool alloc_kmap)
182 {
183 	struct drm_gem_object *obj = &rk_obj->base;
184 	struct drm_device *drm = obj->dev;
185 	struct rockchip_drm_private *private = drm->dev_private;
186 
187 	if (private->domain)
188 		return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
189 	else
190 		return rockchip_gem_alloc_dma(rk_obj, alloc_kmap);
191 }
192 
193 static void rockchip_gem_free_iommu(struct rockchip_gem_object *rk_obj)
194 {
195 	vunmap(rk_obj->kvaddr);
196 	rockchip_gem_iommu_unmap(rk_obj);
197 	rockchip_gem_put_pages(rk_obj);
198 }
199 
200 static void rockchip_gem_free_dma(struct rockchip_gem_object *rk_obj)
201 {
202 	struct drm_gem_object *obj = &rk_obj->base;
203 	struct drm_device *drm = obj->dev;
204 
205 	dma_free_attrs(drm->dev, obj->size, rk_obj->kvaddr, rk_obj->dma_addr,
206 		       rk_obj->dma_attrs);
207 }
208 
209 static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
210 {
211 	if (rk_obj->pages)
212 		rockchip_gem_free_iommu(rk_obj);
213 	else
214 		rockchip_gem_free_dma(rk_obj);
215 }
216 
217 static int rockchip_drm_gem_object_mmap_iommu(struct drm_gem_object *obj,
218 					      struct vm_area_struct *vma)
219 {
220 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
221 	unsigned int i, count = obj->size >> PAGE_SHIFT;
222 	unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
223 	unsigned long uaddr = vma->vm_start;
224 	unsigned long offset = vma->vm_pgoff;
225 	unsigned long end = user_count + offset;
226 	int ret;
227 
228 	if (user_count == 0)
229 		return -ENXIO;
230 	if (end > count)
231 		return -ENXIO;
232 
233 	for (i = offset; i < end; i++) {
234 		ret = vm_insert_page(vma, uaddr, rk_obj->pages[i]);
235 		if (ret)
236 			return ret;
237 		uaddr += PAGE_SIZE;
238 	}
239 
240 	return 0;
241 }
242 
243 static int rockchip_drm_gem_object_mmap_dma(struct drm_gem_object *obj,
244 					    struct vm_area_struct *vma)
245 {
246 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
247 	struct drm_device *drm = obj->dev;
248 
249 	return dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
250 			      obj->size, rk_obj->dma_attrs);
251 }
252 
253 static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
254 					struct vm_area_struct *vma)
255 {
256 	int ret;
257 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
258 
259 	/*
260 	 * We allocated a struct page table for rk_obj, so clear
261 	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
262 	 */
263 	vma->vm_flags &= ~VM_PFNMAP;
264 	vma->vm_pgoff = 0;
265 
266 	if (rk_obj->pages)
267 		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
268 	else
269 		ret = rockchip_drm_gem_object_mmap_dma(obj, vma);
270 
271 	if (ret)
272 		drm_gem_vm_close(vma);
273 
274 	return ret;
275 }
276 
277 int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
278 			  struct vm_area_struct *vma)
279 {
280 	int ret;
281 
282 	ret = drm_gem_mmap_obj(obj, obj->size, vma);
283 	if (ret)
284 		return ret;
285 
286 	return rockchip_drm_gem_object_mmap(obj, vma);
287 }
288 
289 /* drm driver mmap file operations */
290 int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
291 {
292 	struct drm_gem_object *obj;
293 	int ret;
294 
295 	ret = drm_gem_mmap(filp, vma);
296 	if (ret)
297 		return ret;
298 
299 	obj = vma->vm_private_data;
300 
301 	return rockchip_drm_gem_object_mmap(obj, vma);
302 }
303 
304 static void rockchip_gem_release_object(struct rockchip_gem_object *rk_obj)
305 {
306 	drm_gem_object_release(&rk_obj->base);
307 	kfree(rk_obj);
308 }
309 
310 struct rockchip_gem_object *
311 	rockchip_gem_create_object(struct drm_device *drm, unsigned int size,
312 				   bool alloc_kmap)
313 {
314 	struct rockchip_gem_object *rk_obj;
315 	struct drm_gem_object *obj;
316 	int ret;
317 
318 	size = round_up(size, PAGE_SIZE);
319 
320 	rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
321 	if (!rk_obj)
322 		return ERR_PTR(-ENOMEM);
323 
324 	obj = &rk_obj->base;
325 
326 	drm_gem_object_init(drm, obj, size);
327 
328 	ret = rockchip_gem_alloc_buf(rk_obj, alloc_kmap);
329 	if (ret)
330 		goto err_free_rk_obj;
331 
332 	return rk_obj;
333 
334 err_free_rk_obj:
335 	rockchip_gem_release_object(rk_obj);
336 	return ERR_PTR(ret);
337 }
338 
339 /*
340  * rockchip_gem_free_object - (struct drm_driver)->gem_free_object callback
341  * function
342  */
343 void rockchip_gem_free_object(struct drm_gem_object *obj)
344 {
345 	struct rockchip_gem_object *rk_obj;
346 
347 	rk_obj = to_rockchip_obj(obj);
348 
349 	rockchip_gem_free_buf(rk_obj);
350 
351 	rockchip_gem_release_object(rk_obj);
352 }
353 
354 /*
355  * rockchip_gem_create_with_handle - allocate an object with the given
356  * size and create a gem handle on it
357  *
358  * returns a struct rockchip_gem_object* on success or ERR_PTR values
359  * on failure.
360  */
361 static struct rockchip_gem_object *
362 rockchip_gem_create_with_handle(struct drm_file *file_priv,
363 				struct drm_device *drm, unsigned int size,
364 				unsigned int *handle)
365 {
366 	struct rockchip_gem_object *rk_obj;
367 	struct drm_gem_object *obj;
368 	int ret;
369 
370 	rk_obj = rockchip_gem_create_object(drm, size, false);
371 	if (IS_ERR(rk_obj))
372 		return ERR_CAST(rk_obj);
373 
374 	obj = &rk_obj->base;
375 
376 	/*
377 	 * allocate a id of idr table where the obj is registered
378 	 * and handle has the id what user can see.
379 	 */
380 	ret = drm_gem_handle_create(file_priv, obj, handle);
381 	if (ret)
382 		goto err_handle_create;
383 
384 	/* drop reference from allocate - handle holds it now. */
385 	drm_gem_object_unreference_unlocked(obj);
386 
387 	return rk_obj;
388 
389 err_handle_create:
390 	rockchip_gem_free_object(obj);
391 
392 	return ERR_PTR(ret);
393 }
394 
395 int rockchip_gem_dumb_map_offset(struct drm_file *file_priv,
396 				 struct drm_device *dev, uint32_t handle,
397 				 uint64_t *offset)
398 {
399 	struct drm_gem_object *obj;
400 	int ret;
401 
402 	obj = drm_gem_object_lookup(file_priv, handle);
403 	if (!obj) {
404 		DRM_ERROR("failed to lookup gem object.\n");
405 		return -EINVAL;
406 	}
407 
408 	ret = drm_gem_create_mmap_offset(obj);
409 	if (ret)
410 		goto out;
411 
412 	*offset = drm_vma_node_offset_addr(&obj->vma_node);
413 	DRM_DEBUG_KMS("offset = 0x%llx\n", *offset);
414 
415 out:
416 	drm_gem_object_unreference_unlocked(obj);
417 
418 	return 0;
419 }
420 
421 /*
422  * rockchip_gem_dumb_create - (struct drm_driver)->dumb_create callback
423  * function
424  *
425  * This aligns the pitch and size arguments to the minimum required. wrap
426  * this into your own function if you need bigger alignment.
427  */
428 int rockchip_gem_dumb_create(struct drm_file *file_priv,
429 			     struct drm_device *dev,
430 			     struct drm_mode_create_dumb *args)
431 {
432 	struct rockchip_gem_object *rk_obj;
433 	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
434 
435 	/*
436 	 * align to 64 bytes since Mali requires it.
437 	 */
438 	args->pitch = ALIGN(min_pitch, 64);
439 	args->size = args->pitch * args->height;
440 
441 	rk_obj = rockchip_gem_create_with_handle(file_priv, dev, args->size,
442 						 &args->handle);
443 
444 	return PTR_ERR_OR_ZERO(rk_obj);
445 }
446 
447 /*
448  * Allocate a sg_table for this GEM object.
449  * Note: Both the table's contents, and the sg_table itself must be freed by
450  *       the caller.
451  * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
452  */
453 struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
454 {
455 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
456 	struct drm_device *drm = obj->dev;
457 	struct sg_table *sgt;
458 	int ret;
459 
460 	if (rk_obj->pages)
461 		return drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
462 
463 	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
464 	if (!sgt)
465 		return ERR_PTR(-ENOMEM);
466 
467 	ret = dma_get_sgtable_attrs(drm->dev, sgt, rk_obj->kvaddr,
468 				    rk_obj->dma_addr, obj->size,
469 				    rk_obj->dma_attrs);
470 	if (ret) {
471 		DRM_ERROR("failed to allocate sgt, %d\n", ret);
472 		kfree(sgt);
473 		return ERR_PTR(ret);
474 	}
475 
476 	return sgt;
477 }
478 
479 void *rockchip_gem_prime_vmap(struct drm_gem_object *obj)
480 {
481 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
482 
483 	if (rk_obj->pages)
484 		return vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
485 			    pgprot_writecombine(PAGE_KERNEL));
486 
487 	if (rk_obj->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING)
488 		return NULL;
489 
490 	return rk_obj->kvaddr;
491 }
492 
493 void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
494 {
495 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
496 
497 	if (rk_obj->pages) {
498 		vunmap(vaddr);
499 		return;
500 	}
501 
502 	/* Nothing to do if allocated by DMA mapping API. */
503 }
504