1 /*
2  * Copyright (C) 2012 Russell King
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #include <linux/dma-buf.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/shmem_fs.h>
11 #include <drm/drmP.h>
12 #include "armada_drm.h"
13 #include "armada_gem.h"
14 #include <drm/armada_drm.h>
15 #include "armada_ioctlP.h"
16 
17 static int armada_gem_vm_fault(struct vm_fault *vmf)
18 {
19 	struct drm_gem_object *gobj = vmf->vma->vm_private_data;
20 	struct armada_gem_object *obj = drm_to_armada_gem(gobj);
21 	unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
22 	int ret;
23 
24 	pfn += (vmf->address - vmf->vma->vm_start) >> PAGE_SHIFT;
25 	ret = vm_insert_pfn(vmf->vma, vmf->address, pfn);
26 
27 	switch (ret) {
28 	case 0:
29 	case -EBUSY:
30 		return VM_FAULT_NOPAGE;
31 	case -ENOMEM:
32 		return VM_FAULT_OOM;
33 	default:
34 		return VM_FAULT_SIGBUS;
35 	}
36 }
37 
38 const struct vm_operations_struct armada_gem_vm_ops = {
39 	.fault	= armada_gem_vm_fault,
40 	.open	= drm_gem_vm_open,
41 	.close	= drm_gem_vm_close,
42 };
43 
44 static size_t roundup_gem_size(size_t size)
45 {
46 	return roundup(size, PAGE_SIZE);
47 }
48 
49 void armada_gem_free_object(struct drm_gem_object *obj)
50 {
51 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
52 	struct armada_private *priv = obj->dev->dev_private;
53 
54 	DRM_DEBUG_DRIVER("release obj %p\n", dobj);
55 
56 	drm_gem_free_mmap_offset(&dobj->obj);
57 
58 	might_lock(&priv->linear_lock);
59 
60 	if (dobj->page) {
61 		/* page backed memory */
62 		unsigned int order = get_order(dobj->obj.size);
63 		__free_pages(dobj->page, order);
64 	} else if (dobj->linear) {
65 		/* linear backed memory */
66 		mutex_lock(&priv->linear_lock);
67 		drm_mm_remove_node(dobj->linear);
68 		mutex_unlock(&priv->linear_lock);
69 		kfree(dobj->linear);
70 		if (dobj->addr)
71 			iounmap(dobj->addr);
72 	}
73 
74 	if (dobj->obj.import_attach) {
75 		/* We only ever display imported data */
76 		if (dobj->sgt)
77 			dma_buf_unmap_attachment(dobj->obj.import_attach,
78 						 dobj->sgt, DMA_TO_DEVICE);
79 		drm_prime_gem_destroy(&dobj->obj, NULL);
80 	}
81 
82 	drm_gem_object_release(&dobj->obj);
83 
84 	kfree(dobj);
85 }
86 
87 int
88 armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
89 {
90 	struct armada_private *priv = dev->dev_private;
91 	size_t size = obj->obj.size;
92 
93 	if (obj->page || obj->linear)
94 		return 0;
95 
96 	/*
97 	 * If it is a small allocation (typically cursor, which will
98 	 * be 32x64 or 64x32 ARGB pixels) try to get it from the system.
99 	 * Framebuffers will never be this small (our minimum size for
100 	 * framebuffers is larger than this anyway.)  Such objects are
101 	 * only accessed by the CPU so we don't need any special handing
102 	 * here.
103 	 */
104 	if (size <= 8192) {
105 		unsigned int order = get_order(size);
106 		struct page *p = alloc_pages(GFP_KERNEL, order);
107 
108 		if (p) {
109 			obj->addr = page_address(p);
110 			obj->phys_addr = page_to_phys(p);
111 			obj->page = p;
112 
113 			memset(obj->addr, 0, PAGE_ALIGN(size));
114 		}
115 	}
116 
117 	/*
118 	 * We could grab something from CMA if it's enabled, but that
119 	 * involves building in a problem:
120 	 *
121 	 * CMA's interface uses dma_alloc_coherent(), which provides us
122 	 * with an CPU virtual address and a device address.
123 	 *
124 	 * The CPU virtual address may be either an address in the kernel
125 	 * direct mapped region (for example, as it would be on x86) or
126 	 * it may be remapped into another part of kernel memory space
127 	 * (eg, as it would be on ARM.)  This means virt_to_phys() on the
128 	 * returned virtual address is invalid depending on the architecture
129 	 * implementation.
130 	 *
131 	 * The device address may also not be a physical address; it may
132 	 * be that there is some kind of remapping between the device and
133 	 * system RAM, which makes the use of the device address also
134 	 * unsafe to re-use as a physical address.
135 	 *
136 	 * This makes DRM usage of dma_alloc_coherent() in a generic way
137 	 * at best very questionable and unsafe.
138 	 */
139 
140 	/* Otherwise, grab it from our linear allocation */
141 	if (!obj->page) {
142 		struct drm_mm_node *node;
143 		unsigned align = min_t(unsigned, size, SZ_2M);
144 		void __iomem *ptr;
145 		int ret;
146 
147 		node = kzalloc(sizeof(*node), GFP_KERNEL);
148 		if (!node)
149 			return -ENOSPC;
150 
151 		mutex_lock(&priv->linear_lock);
152 		ret = drm_mm_insert_node_generic(&priv->linear, node,
153 						 size, align, 0, 0);
154 		mutex_unlock(&priv->linear_lock);
155 		if (ret) {
156 			kfree(node);
157 			return ret;
158 		}
159 
160 		obj->linear = node;
161 
162 		/* Ensure that the memory we're returning is cleared. */
163 		ptr = ioremap_wc(obj->linear->start, size);
164 		if (!ptr) {
165 			mutex_lock(&priv->linear_lock);
166 			drm_mm_remove_node(obj->linear);
167 			mutex_unlock(&priv->linear_lock);
168 			kfree(obj->linear);
169 			obj->linear = NULL;
170 			return -ENOMEM;
171 		}
172 
173 		memset_io(ptr, 0, size);
174 		iounmap(ptr);
175 
176 		obj->phys_addr = obj->linear->start;
177 		obj->dev_addr = obj->linear->start;
178 	}
179 
180 	DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
181 			 (unsigned long long)obj->phys_addr,
182 			 (unsigned long long)obj->dev_addr);
183 
184 	return 0;
185 }
186 
187 void *
188 armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
189 {
190 	/* only linear objects need to be ioremap'd */
191 	if (!dobj->addr && dobj->linear)
192 		dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
193 	return dobj->addr;
194 }
195 
196 struct armada_gem_object *
197 armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
198 {
199 	struct armada_gem_object *obj;
200 
201 	size = roundup_gem_size(size);
202 
203 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
204 	if (!obj)
205 		return NULL;
206 
207 	drm_gem_private_object_init(dev, &obj->obj, size);
208 	obj->dev_addr = DMA_ERROR_CODE;
209 
210 	DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);
211 
212 	return obj;
213 }
214 
215 static struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
216 	size_t size)
217 {
218 	struct armada_gem_object *obj;
219 	struct address_space *mapping;
220 
221 	size = roundup_gem_size(size);
222 
223 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
224 	if (!obj)
225 		return NULL;
226 
227 	if (drm_gem_object_init(dev, &obj->obj, size)) {
228 		kfree(obj);
229 		return NULL;
230 	}
231 
232 	obj->dev_addr = DMA_ERROR_CODE;
233 
234 	mapping = obj->obj.filp->f_mapping;
235 	mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
236 
237 	DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);
238 
239 	return obj;
240 }
241 
242 /* Dumb alloc support */
243 int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
244 	struct drm_mode_create_dumb *args)
245 {
246 	struct armada_gem_object *dobj;
247 	u32 handle;
248 	size_t size;
249 	int ret;
250 
251 	args->pitch = armada_pitch(args->width, args->bpp);
252 	args->size = size = args->pitch * args->height;
253 
254 	dobj = armada_gem_alloc_private_object(dev, size);
255 	if (dobj == NULL)
256 		return -ENOMEM;
257 
258 	ret = armada_gem_linear_back(dev, dobj);
259 	if (ret)
260 		goto err;
261 
262 	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
263 	if (ret)
264 		goto err;
265 
266 	args->handle = handle;
267 
268 	/* drop reference from allocate - handle holds it now */
269 	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
270  err:
271 	drm_gem_object_unreference_unlocked(&dobj->obj);
272 	return ret;
273 }
274 
275 int armada_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
276 	uint32_t handle, uint64_t *offset)
277 {
278 	struct armada_gem_object *obj;
279 	int ret = 0;
280 
281 	obj = armada_gem_object_lookup(file, handle);
282 	if (!obj) {
283 		DRM_ERROR("failed to lookup gem object\n");
284 		return -EINVAL;
285 	}
286 
287 	/* Don't allow imported objects to be mapped */
288 	if (obj->obj.import_attach) {
289 		ret = -EINVAL;
290 		goto err_unref;
291 	}
292 
293 	ret = drm_gem_create_mmap_offset(&obj->obj);
294 	if (ret == 0) {
295 		*offset = drm_vma_node_offset_addr(&obj->obj.vma_node);
296 		DRM_DEBUG_DRIVER("handle %#x offset %llx\n", handle, *offset);
297 	}
298 
299  err_unref:
300 	drm_gem_object_unreference_unlocked(&obj->obj);
301 
302 	return ret;
303 }
304 
305 int armada_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
306 	uint32_t handle)
307 {
308 	return drm_gem_handle_delete(file, handle);
309 }
310 
311 /* Private driver gem ioctls */
312 int armada_gem_create_ioctl(struct drm_device *dev, void *data,
313 	struct drm_file *file)
314 {
315 	struct drm_armada_gem_create *args = data;
316 	struct armada_gem_object *dobj;
317 	size_t size;
318 	u32 handle;
319 	int ret;
320 
321 	if (args->size == 0)
322 		return -ENOMEM;
323 
324 	size = args->size;
325 
326 	dobj = armada_gem_alloc_object(dev, size);
327 	if (dobj == NULL)
328 		return -ENOMEM;
329 
330 	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
331 	if (ret)
332 		goto err;
333 
334 	args->handle = handle;
335 
336 	/* drop reference from allocate - handle holds it now */
337 	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
338  err:
339 	drm_gem_object_unreference_unlocked(&dobj->obj);
340 	return ret;
341 }
342 
343 /* Map a shmem-backed object into process memory space */
344 int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
345 	struct drm_file *file)
346 {
347 	struct drm_armada_gem_mmap *args = data;
348 	struct armada_gem_object *dobj;
349 	unsigned long addr;
350 
351 	dobj = armada_gem_object_lookup(file, args->handle);
352 	if (dobj == NULL)
353 		return -ENOENT;
354 
355 	if (!dobj->obj.filp) {
356 		drm_gem_object_unreference_unlocked(&dobj->obj);
357 		return -EINVAL;
358 	}
359 
360 	addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
361 		       MAP_SHARED, args->offset);
362 	drm_gem_object_unreference_unlocked(&dobj->obj);
363 	if (IS_ERR_VALUE(addr))
364 		return addr;
365 
366 	args->addr = addr;
367 
368 	return 0;
369 }
370 
371 int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
372 	struct drm_file *file)
373 {
374 	struct drm_armada_gem_pwrite *args = data;
375 	struct armada_gem_object *dobj;
376 	char __user *ptr;
377 	int ret;
378 
379 	DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
380 		args->handle, args->offset, args->size, args->ptr);
381 
382 	if (args->size == 0)
383 		return 0;
384 
385 	ptr = (char __user *)(uintptr_t)args->ptr;
386 
387 	if (!access_ok(VERIFY_READ, ptr, args->size))
388 		return -EFAULT;
389 
390 	ret = fault_in_pages_readable(ptr, args->size);
391 	if (ret)
392 		return ret;
393 
394 	dobj = armada_gem_object_lookup(file, args->handle);
395 	if (dobj == NULL)
396 		return -ENOENT;
397 
398 	/* Must be a kernel-mapped object */
399 	if (!dobj->addr)
400 		return -EINVAL;
401 
402 	if (args->offset > dobj->obj.size ||
403 	    args->size > dobj->obj.size - args->offset) {
404 		DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
405 		ret = -EINVAL;
406 		goto unref;
407 	}
408 
409 	if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
410 		ret = -EFAULT;
411 	} else if (dobj->update) {
412 		dobj->update(dobj->update_data);
413 		ret = 0;
414 	}
415 
416  unref:
417 	drm_gem_object_unreference_unlocked(&dobj->obj);
418 	return ret;
419 }
420 
421 /* Prime support */
422 static struct sg_table *
423 armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
424 	enum dma_data_direction dir)
425 {
426 	struct drm_gem_object *obj = attach->dmabuf->priv;
427 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
428 	struct scatterlist *sg;
429 	struct sg_table *sgt;
430 	int i, num;
431 
432 	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
433 	if (!sgt)
434 		return NULL;
435 
436 	if (dobj->obj.filp) {
437 		struct address_space *mapping;
438 		int count;
439 
440 		count = dobj->obj.size / PAGE_SIZE;
441 		if (sg_alloc_table(sgt, count, GFP_KERNEL))
442 			goto free_sgt;
443 
444 		mapping = dobj->obj.filp->f_mapping;
445 
446 		for_each_sg(sgt->sgl, sg, count, i) {
447 			struct page *page;
448 
449 			page = shmem_read_mapping_page(mapping, i);
450 			if (IS_ERR(page)) {
451 				num = i;
452 				goto release;
453 			}
454 
455 			sg_set_page(sg, page, PAGE_SIZE, 0);
456 		}
457 
458 		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
459 			num = sgt->nents;
460 			goto release;
461 		}
462 	} else if (dobj->page) {
463 		/* Single contiguous page */
464 		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
465 			goto free_sgt;
466 
467 		sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
468 
469 		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
470 			goto free_table;
471 	} else if (dobj->linear) {
472 		/* Single contiguous physical region - no struct page */
473 		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
474 			goto free_sgt;
475 		sg_dma_address(sgt->sgl) = dobj->dev_addr;
476 		sg_dma_len(sgt->sgl) = dobj->obj.size;
477 	} else {
478 		goto free_sgt;
479 	}
480 	return sgt;
481 
482  release:
483 	for_each_sg(sgt->sgl, sg, num, i)
484 		put_page(sg_page(sg));
485  free_table:
486 	sg_free_table(sgt);
487  free_sgt:
488 	kfree(sgt);
489 	return NULL;
490 }
491 
492 static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
493 	struct sg_table *sgt, enum dma_data_direction dir)
494 {
495 	struct drm_gem_object *obj = attach->dmabuf->priv;
496 	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
497 	int i;
498 
499 	if (!dobj->linear)
500 		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
501 
502 	if (dobj->obj.filp) {
503 		struct scatterlist *sg;
504 		for_each_sg(sgt->sgl, sg, sgt->nents, i)
505 			put_page(sg_page(sg));
506 	}
507 
508 	sg_free_table(sgt);
509 	kfree(sgt);
510 }
511 
512 static void *armada_gem_dmabuf_no_kmap(struct dma_buf *buf, unsigned long n)
513 {
514 	return NULL;
515 }
516 
517 static void
518 armada_gem_dmabuf_no_kunmap(struct dma_buf *buf, unsigned long n, void *addr)
519 {
520 }
521 
522 static int
523 armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
524 {
525 	return -EINVAL;
526 }
527 
528 static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
529 	.map_dma_buf	= armada_gem_prime_map_dma_buf,
530 	.unmap_dma_buf	= armada_gem_prime_unmap_dma_buf,
531 	.release	= drm_gem_dmabuf_release,
532 	.kmap_atomic	= armada_gem_dmabuf_no_kmap,
533 	.kunmap_atomic	= armada_gem_dmabuf_no_kunmap,
534 	.kmap		= armada_gem_dmabuf_no_kmap,
535 	.kunmap		= armada_gem_dmabuf_no_kunmap,
536 	.mmap		= armada_gem_dmabuf_mmap,
537 };
538 
539 struct dma_buf *
540 armada_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj,
541 	int flags)
542 {
543 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
544 
545 	exp_info.ops = &armada_gem_prime_dmabuf_ops;
546 	exp_info.size = obj->size;
547 	exp_info.flags = O_RDWR;
548 	exp_info.priv = obj;
549 
550 	return drm_gem_dmabuf_export(dev, &exp_info);
551 }
552 
553 struct drm_gem_object *
554 armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
555 {
556 	struct dma_buf_attachment *attach;
557 	struct armada_gem_object *dobj;
558 
559 	if (buf->ops == &armada_gem_prime_dmabuf_ops) {
560 		struct drm_gem_object *obj = buf->priv;
561 		if (obj->dev == dev) {
562 			/*
563 			 * Importing our own dmabuf(s) increases the
564 			 * refcount on the gem object itself.
565 			 */
566 			drm_gem_object_reference(obj);
567 			return obj;
568 		}
569 	}
570 
571 	attach = dma_buf_attach(buf, dev->dev);
572 	if (IS_ERR(attach))
573 		return ERR_CAST(attach);
574 
575 	dobj = armada_gem_alloc_private_object(dev, buf->size);
576 	if (!dobj) {
577 		dma_buf_detach(buf, attach);
578 		return ERR_PTR(-ENOMEM);
579 	}
580 
581 	dobj->obj.import_attach = attach;
582 	get_dma_buf(buf);
583 
584 	/*
585 	 * Don't call dma_buf_map_attachment() here - it maps the
586 	 * scatterlist immediately for DMA, and this is not always
587 	 * an appropriate thing to do.
588 	 */
589 	return &dobj->obj;
590 }
591 
592 int armada_gem_map_import(struct armada_gem_object *dobj)
593 {
594 	int ret;
595 
596 	dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
597 					   DMA_TO_DEVICE);
598 	if (IS_ERR(dobj->sgt)) {
599 		ret = PTR_ERR(dobj->sgt);
600 		dobj->sgt = NULL;
601 		DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
602 		return ret;
603 	}
604 	if (dobj->sgt->nents > 1) {
605 		DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
606 		return -EINVAL;
607 	}
608 	if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
609 		DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
610 		return -EINVAL;
611 	}
612 	dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
613 	return 0;
614 }
615