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v3.15
  1/**
  2 * \file drm_vm.c
  3 * Memory mapping for DRM
  4 *
  5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
  6 * \author Gareth Hughes <gareth@valinux.com>
  7 */
  8
  9/*
 10 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
 11 *
 12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 14 * All Rights Reserved.
 15 *
 16 * Permission is hereby granted, free of charge, to any person obtaining a
 17 * copy of this software and associated documentation files (the "Software"),
 18 * to deal in the Software without restriction, including without limitation
 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 20 * and/or sell copies of the Software, and to permit persons to whom the
 21 * Software is furnished to do so, subject to the following conditions:
 22 *
 23 * The above copyright notice and this permission notice (including the next
 24 * paragraph) shall be included in all copies or substantial portions of the
 25 * Software.
 26 *
 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 33 * OTHER DEALINGS IN THE SOFTWARE.
 34 */
 35
 36#include <drm/drmP.h>
 37#include <linux/export.h>
 
 38#if defined(__ia64__)
 39#include <linux/efi.h>
 40#include <linux/slab.h>
 41#endif
 
 
 
 
 
 
 
 
 
 42
 43static void drm_vm_open(struct vm_area_struct *vma);
 44static void drm_vm_close(struct vm_area_struct *vma);
 45
 46static pgprot_t drm_io_prot(struct drm_local_map *map,
 47			    struct vm_area_struct *vma)
 48{
 49	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 50
 51#if defined(__i386__) || defined(__x86_64__)
 52	if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))
 53		tmp = pgprot_noncached(tmp);
 54	else
 55		tmp = pgprot_writecombine(tmp);
 56#elif defined(__powerpc__)
 57	pgprot_val(tmp) |= _PAGE_NO_CACHE;
 58	if (map->type == _DRM_REGISTERS)
 59		pgprot_val(tmp) |= _PAGE_GUARDED;
 60#elif defined(__ia64__)
 61	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
 62				    vma->vm_start))
 63		tmp = pgprot_writecombine(tmp);
 64	else
 65		tmp = pgprot_noncached(tmp);
 66#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
 67	tmp = pgprot_noncached(tmp);
 68#endif
 69	return tmp;
 70}
 71
 72static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
 73{
 74	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 75
 76#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
 77	tmp |= _PAGE_NO_CACHE;
 78#endif
 79	return tmp;
 80}
 81
 82/**
 83 * \c fault method for AGP virtual memory.
 84 *
 85 * \param vma virtual memory area.
 86 * \param address access address.
 87 * \return pointer to the page structure.
 88 *
 89 * Find the right map and if it's AGP memory find the real physical page to
 90 * map, get the page, increment the use count and return it.
 91 */
 92#if __OS_HAS_AGP
 93static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 94{
 95	struct drm_file *priv = vma->vm_file->private_data;
 96	struct drm_device *dev = priv->minor->dev;
 97	struct drm_local_map *map = NULL;
 98	struct drm_map_list *r_list;
 99	struct drm_hash_item *hash;
100
101	/*
102	 * Find the right map
103	 */
104	if (!dev->agp)
105		goto vm_fault_error;
106
107	if (!dev->agp || !dev->agp->cant_use_aperture)
108		goto vm_fault_error;
109
110	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
111		goto vm_fault_error;
112
113	r_list = drm_hash_entry(hash, struct drm_map_list, hash);
114	map = r_list->map;
115
116	if (map && map->type == _DRM_AGP) {
117		/*
118		 * Using vm_pgoff as a selector forces us to use this unusual
119		 * addressing scheme.
120		 */
121		resource_size_t offset = (unsigned long)vmf->virtual_address -
122			vma->vm_start;
123		resource_size_t baddr = map->offset + offset;
124		struct drm_agp_mem *agpmem;
125		struct page *page;
126
127#ifdef __alpha__
128		/*
129		 * Adjust to a bus-relative address
130		 */
131		baddr -= dev->hose->mem_space->start;
132#endif
133
134		/*
135		 * It's AGP memory - find the real physical page to map
136		 */
137		list_for_each_entry(agpmem, &dev->agp->memory, head) {
138			if (agpmem->bound <= baddr &&
139			    agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
140				break;
141		}
142
143		if (&agpmem->head == &dev->agp->memory)
144			goto vm_fault_error;
145
146		/*
147		 * Get the page, inc the use count, and return it
148		 */
149		offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
150		page = agpmem->memory->pages[offset];
151		get_page(page);
152		vmf->page = page;
153
154		DRM_DEBUG
155		    ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
156		     (unsigned long long)baddr,
157		     agpmem->memory->pages[offset],
158		     (unsigned long long)offset,
159		     page_count(page));
160		return 0;
161	}
162vm_fault_error:
163	return VM_FAULT_SIGBUS;	/* Disallow mremap */
164}
165#else				/* __OS_HAS_AGP */
166static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
167{
168	return VM_FAULT_SIGBUS;
169}
170#endif				/* __OS_HAS_AGP */
171
172/**
173 * \c nopage method for shared virtual memory.
174 *
175 * \param vma virtual memory area.
176 * \param address access address.
177 * \return pointer to the page structure.
178 *
179 * Get the mapping, find the real physical page to map, get the page, and
180 * return it.
181 */
182static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
183{
184	struct drm_local_map *map = vma->vm_private_data;
185	unsigned long offset;
186	unsigned long i;
187	struct page *page;
188
189	if (!map)
190		return VM_FAULT_SIGBUS;	/* Nothing allocated */
191
192	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
193	i = (unsigned long)map->handle + offset;
194	page = vmalloc_to_page((void *)i);
195	if (!page)
196		return VM_FAULT_SIGBUS;
197	get_page(page);
198	vmf->page = page;
199
200	DRM_DEBUG("shm_fault 0x%lx\n", offset);
201	return 0;
202}
203
204/**
205 * \c close method for shared virtual memory.
206 *
207 * \param vma virtual memory area.
208 *
209 * Deletes map information if we are the last
210 * person to close a mapping and it's not in the global maplist.
211 */
212static void drm_vm_shm_close(struct vm_area_struct *vma)
213{
214	struct drm_file *priv = vma->vm_file->private_data;
215	struct drm_device *dev = priv->minor->dev;
216	struct drm_vma_entry *pt, *temp;
217	struct drm_local_map *map;
218	struct drm_map_list *r_list;
219	int found_maps = 0;
220
221	DRM_DEBUG("0x%08lx,0x%08lx\n",
222		  vma->vm_start, vma->vm_end - vma->vm_start);
223
224	map = vma->vm_private_data;
225
226	mutex_lock(&dev->struct_mutex);
227	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
228		if (pt->vma->vm_private_data == map)
229			found_maps++;
230		if (pt->vma == vma) {
231			list_del(&pt->head);
232			kfree(pt);
233		}
234	}
235
236	/* We were the only map that was found */
237	if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
238		/* Check to see if we are in the maplist, if we are not, then
239		 * we delete this mappings information.
240		 */
241		found_maps = 0;
242		list_for_each_entry(r_list, &dev->maplist, head) {
243			if (r_list->map == map)
244				found_maps++;
245		}
246
247		if (!found_maps) {
248			drm_dma_handle_t dmah;
249
250			switch (map->type) {
251			case _DRM_REGISTERS:
252			case _DRM_FRAME_BUFFER:
253				arch_phys_wc_del(map->mtrr);
254				iounmap(map->handle);
255				break;
256			case _DRM_SHM:
257				vfree(map->handle);
258				break;
259			case _DRM_AGP:
260			case _DRM_SCATTER_GATHER:
261				break;
262			case _DRM_CONSISTENT:
263				dmah.vaddr = map->handle;
264				dmah.busaddr = map->offset;
265				dmah.size = map->size;
266				__drm_pci_free(dev, &dmah);
267				break;
268			}
269			kfree(map);
270		}
271	}
272	mutex_unlock(&dev->struct_mutex);
273}
274
275/**
276 * \c fault method for DMA virtual memory.
277 *
278 * \param vma virtual memory area.
279 * \param address access address.
280 * \return pointer to the page structure.
281 *
282 * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
283 */
284static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
285{
286	struct drm_file *priv = vma->vm_file->private_data;
287	struct drm_device *dev = priv->minor->dev;
288	struct drm_device_dma *dma = dev->dma;
289	unsigned long offset;
290	unsigned long page_nr;
291	struct page *page;
292
293	if (!dma)
294		return VM_FAULT_SIGBUS;	/* Error */
295	if (!dma->pagelist)
296		return VM_FAULT_SIGBUS;	/* Nothing allocated */
297
298	offset = (unsigned long)vmf->virtual_address - vma->vm_start;	/* vm_[pg]off[set] should be 0 */
 
299	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
300	page = virt_to_page((void *)dma->pagelist[page_nr]);
301
302	get_page(page);
303	vmf->page = page;
304
305	DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
306	return 0;
307}
308
309/**
310 * \c fault method for scatter-gather virtual memory.
311 *
312 * \param vma virtual memory area.
313 * \param address access address.
314 * \return pointer to the page structure.
315 *
316 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
317 */
318static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
319{
320	struct drm_local_map *map = vma->vm_private_data;
321	struct drm_file *priv = vma->vm_file->private_data;
322	struct drm_device *dev = priv->minor->dev;
323	struct drm_sg_mem *entry = dev->sg;
324	unsigned long offset;
325	unsigned long map_offset;
326	unsigned long page_offset;
327	struct page *page;
328
329	if (!entry)
330		return VM_FAULT_SIGBUS;	/* Error */
331	if (!entry->pagelist)
332		return VM_FAULT_SIGBUS;	/* Nothing allocated */
333
334	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
335	map_offset = map->offset - (unsigned long)dev->sg->virtual;
336	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
337	page = entry->pagelist[page_offset];
338	get_page(page);
339	vmf->page = page;
340
341	return 0;
342}
343
344static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
345{
346	return drm_do_vm_fault(vma, vmf);
347}
348
349static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
350{
351	return drm_do_vm_shm_fault(vma, vmf);
352}
353
354static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
355{
356	return drm_do_vm_dma_fault(vma, vmf);
357}
358
359static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
360{
361	return drm_do_vm_sg_fault(vma, vmf);
362}
363
364/** AGP virtual memory operations */
365static const struct vm_operations_struct drm_vm_ops = {
366	.fault = drm_vm_fault,
367	.open = drm_vm_open,
368	.close = drm_vm_close,
369};
370
371/** Shared virtual memory operations */
372static const struct vm_operations_struct drm_vm_shm_ops = {
373	.fault = drm_vm_shm_fault,
374	.open = drm_vm_open,
375	.close = drm_vm_shm_close,
376};
377
378/** DMA virtual memory operations */
379static const struct vm_operations_struct drm_vm_dma_ops = {
380	.fault = drm_vm_dma_fault,
381	.open = drm_vm_open,
382	.close = drm_vm_close,
383};
384
385/** Scatter-gather virtual memory operations */
386static const struct vm_operations_struct drm_vm_sg_ops = {
387	.fault = drm_vm_sg_fault,
388	.open = drm_vm_open,
389	.close = drm_vm_close,
390};
391
392/**
393 * \c open method for shared virtual memory.
394 *
395 * \param vma virtual memory area.
396 *
397 * Create a new drm_vma_entry structure as the \p vma private data entry and
398 * add it to drm_device::vmalist.
399 */
400void drm_vm_open_locked(struct drm_device *dev,
401		struct vm_area_struct *vma)
402{
403	struct drm_vma_entry *vma_entry;
404
405	DRM_DEBUG("0x%08lx,0x%08lx\n",
406		  vma->vm_start, vma->vm_end - vma->vm_start);
407
408	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
409	if (vma_entry) {
410		vma_entry->vma = vma;
411		vma_entry->pid = current->pid;
412		list_add(&vma_entry->head, &dev->vmalist);
413	}
414}
415EXPORT_SYMBOL_GPL(drm_vm_open_locked);
416
417static void drm_vm_open(struct vm_area_struct *vma)
418{
419	struct drm_file *priv = vma->vm_file->private_data;
420	struct drm_device *dev = priv->minor->dev;
421
422	mutex_lock(&dev->struct_mutex);
423	drm_vm_open_locked(dev, vma);
424	mutex_unlock(&dev->struct_mutex);
425}
426
427void drm_vm_close_locked(struct drm_device *dev,
428		struct vm_area_struct *vma)
429{
430	struct drm_vma_entry *pt, *temp;
431
432	DRM_DEBUG("0x%08lx,0x%08lx\n",
433		  vma->vm_start, vma->vm_end - vma->vm_start);
434
435	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
436		if (pt->vma == vma) {
437			list_del(&pt->head);
438			kfree(pt);
439			break;
440		}
441	}
442}
443
444/**
445 * \c close method for all virtual memory types.
446 *
447 * \param vma virtual memory area.
448 *
449 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
450 * free it.
451 */
452static void drm_vm_close(struct vm_area_struct *vma)
453{
454	struct drm_file *priv = vma->vm_file->private_data;
455	struct drm_device *dev = priv->minor->dev;
456
457	mutex_lock(&dev->struct_mutex);
458	drm_vm_close_locked(dev, vma);
459	mutex_unlock(&dev->struct_mutex);
460}
461
462/**
463 * mmap DMA memory.
464 *
465 * \param file_priv DRM file private.
466 * \param vma virtual memory area.
467 * \return zero on success or a negative number on failure.
468 *
469 * Sets the virtual memory area operations structure to vm_dma_ops, the file
470 * pointer, and calls vm_open().
471 */
472static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
473{
474	struct drm_file *priv = filp->private_data;
475	struct drm_device *dev;
476	struct drm_device_dma *dma;
477	unsigned long length = vma->vm_end - vma->vm_start;
478
479	dev = priv->minor->dev;
480	dma = dev->dma;
481	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
482		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
483
484	/* Length must match exact page count */
485	if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
486		return -EINVAL;
487	}
488
489	if (!capable(CAP_SYS_ADMIN) &&
490	    (dma->flags & _DRM_DMA_USE_PCI_RO)) {
491		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
492#if defined(__i386__) || defined(__x86_64__)
493		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
494#else
495		/* Ye gads this is ugly.  With more thought
496		   we could move this up higher and use
497		   `protection_map' instead.  */
498		vma->vm_page_prot =
499		    __pgprot(pte_val
500			     (pte_wrprotect
501			      (__pte(pgprot_val(vma->vm_page_prot)))));
502#endif
503	}
504
505	vma->vm_ops = &drm_vm_dma_ops;
506
507	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
508
509	drm_vm_open_locked(dev, vma);
510	return 0;
511}
512
513static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
514{
515#ifdef __alpha__
516	return dev->hose->dense_mem_base;
517#else
518	return 0;
519#endif
520}
521
522/**
523 * mmap DMA memory.
524 *
525 * \param file_priv DRM file private.
526 * \param vma virtual memory area.
527 * \return zero on success or a negative number on failure.
528 *
529 * If the virtual memory area has no offset associated with it then it's a DMA
530 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
531 * checks that the restricted flag is not set, sets the virtual memory operations
532 * according to the mapping type and remaps the pages. Finally sets the file
533 * pointer and calls vm_open().
534 */
535int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
536{
537	struct drm_file *priv = filp->private_data;
538	struct drm_device *dev = priv->minor->dev;
539	struct drm_local_map *map = NULL;
540	resource_size_t offset = 0;
541	struct drm_hash_item *hash;
542
543	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
544		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
545
546	if (!priv->authenticated)
547		return -EACCES;
548
549	/* We check for "dma". On Apple's UniNorth, it's valid to have
550	 * the AGP mapped at physical address 0
551	 * --BenH.
552	 */
553	if (!vma->vm_pgoff
554#if __OS_HAS_AGP
555	    && (!dev->agp
556		|| dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
557#endif
558	    )
559		return drm_mmap_dma(filp, vma);
560
561	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
562		DRM_ERROR("Could not find map\n");
563		return -EINVAL;
564	}
565
566	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
567	if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
568		return -EPERM;
569
570	/* Check for valid size. */
571	if (map->size < vma->vm_end - vma->vm_start)
572		return -EINVAL;
573
574	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
575		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
576#if defined(__i386__) || defined(__x86_64__)
577		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
578#else
579		/* Ye gads this is ugly.  With more thought
580		   we could move this up higher and use
581		   `protection_map' instead.  */
582		vma->vm_page_prot =
583		    __pgprot(pte_val
584			     (pte_wrprotect
585			      (__pte(pgprot_val(vma->vm_page_prot)))));
586#endif
587	}
588
589	switch (map->type) {
590#if !defined(__arm__)
591	case _DRM_AGP:
592		if (dev->agp && dev->agp->cant_use_aperture) {
593			/*
594			 * On some platforms we can't talk to bus dma address from the CPU, so for
595			 * memory of type DRM_AGP, we'll deal with sorting out the real physical
596			 * pages and mappings in fault()
597			 */
598#if defined(__powerpc__)
599			pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
600#endif
601			vma->vm_ops = &drm_vm_ops;
602			break;
603		}
604		/* fall through to _DRM_FRAME_BUFFER... */
605#endif
606	case _DRM_FRAME_BUFFER:
607	case _DRM_REGISTERS:
608		offset = drm_core_get_reg_ofs(dev);
609		vma->vm_page_prot = drm_io_prot(map, vma);
610		if (io_remap_pfn_range(vma, vma->vm_start,
611				       (map->offset + offset) >> PAGE_SHIFT,
612				       vma->vm_end - vma->vm_start,
613				       vma->vm_page_prot))
614			return -EAGAIN;
615		DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
616			  " offset = 0x%llx\n",
617			  map->type,
618			  vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));
619
620		vma->vm_ops = &drm_vm_ops;
621		break;
622	case _DRM_CONSISTENT:
623		/* Consistent memory is really like shared memory. But
624		 * it's allocated in a different way, so avoid fault */
625		if (remap_pfn_range(vma, vma->vm_start,
626		    page_to_pfn(virt_to_page(map->handle)),
627		    vma->vm_end - vma->vm_start, vma->vm_page_prot))
628			return -EAGAIN;
629		vma->vm_page_prot = drm_dma_prot(map->type, vma);
630	/* fall through to _DRM_SHM */
631	case _DRM_SHM:
632		vma->vm_ops = &drm_vm_shm_ops;
633		vma->vm_private_data = (void *)map;
634		break;
635	case _DRM_SCATTER_GATHER:
636		vma->vm_ops = &drm_vm_sg_ops;
637		vma->vm_private_data = (void *)map;
638		vma->vm_page_prot = drm_dma_prot(map->type, vma);
639		break;
640	default:
641		return -EINVAL;	/* This should never happen. */
642	}
643	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
644
645	drm_vm_open_locked(dev, vma);
646	return 0;
647}
648
649int drm_mmap(struct file *filp, struct vm_area_struct *vma)
650{
651	struct drm_file *priv = filp->private_data;
652	struct drm_device *dev = priv->minor->dev;
653	int ret;
654
655	if (drm_device_is_unplugged(dev))
656		return -ENODEV;
657
658	mutex_lock(&dev->struct_mutex);
659	ret = drm_mmap_locked(filp, vma);
660	mutex_unlock(&dev->struct_mutex);
661
662	return ret;
663}
664EXPORT_SYMBOL(drm_mmap);
 
 
 
 
 
 
 
 
 
 
 
v4.10.11
  1/**
  2 * \file drm_vm.c
  3 * Memory mapping for DRM
  4 *
  5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
  6 * \author Gareth Hughes <gareth@valinux.com>
  7 */
  8
  9/*
 10 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
 11 *
 12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 14 * All Rights Reserved.
 15 *
 16 * Permission is hereby granted, free of charge, to any person obtaining a
 17 * copy of this software and associated documentation files (the "Software"),
 18 * to deal in the Software without restriction, including without limitation
 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 20 * and/or sell copies of the Software, and to permit persons to whom the
 21 * Software is furnished to do so, subject to the following conditions:
 22 *
 23 * The above copyright notice and this permission notice (including the next
 24 * paragraph) shall be included in all copies or substantial portions of the
 25 * Software.
 26 *
 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 33 * OTHER DEALINGS IN THE SOFTWARE.
 34 */
 35
 36#include <drm/drmP.h>
 37#include <linux/export.h>
 38#include <linux/seq_file.h>
 39#if defined(__ia64__)
 40#include <linux/efi.h>
 41#include <linux/slab.h>
 42#endif
 43#include <asm/pgtable.h>
 44#include "drm_internal.h"
 45#include "drm_legacy.h"
 46
 47struct drm_vma_entry {
 48	struct list_head head;
 49	struct vm_area_struct *vma;
 50	pid_t pid;
 51};
 52
 53static void drm_vm_open(struct vm_area_struct *vma);
 54static void drm_vm_close(struct vm_area_struct *vma);
 55
 56static pgprot_t drm_io_prot(struct drm_local_map *map,
 57			    struct vm_area_struct *vma)
 58{
 59	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 60
 61#if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__)
 62	if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))
 63		tmp = pgprot_noncached(tmp);
 64	else
 65		tmp = pgprot_writecombine(tmp);
 
 
 
 
 66#elif defined(__ia64__)
 67	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
 68				    vma->vm_start))
 69		tmp = pgprot_writecombine(tmp);
 70	else
 71		tmp = pgprot_noncached(tmp);
 72#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
 73	tmp = pgprot_noncached(tmp);
 74#endif
 75	return tmp;
 76}
 77
 78static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
 79{
 80	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 81
 82#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
 83	tmp = pgprot_noncached_wc(tmp);
 84#endif
 85	return tmp;
 86}
 87
 88/**
 89 * \c fault method for AGP virtual memory.
 90 *
 91 * \param vma virtual memory area.
 92 * \param address access address.
 93 * \return pointer to the page structure.
 94 *
 95 * Find the right map and if it's AGP memory find the real physical page to
 96 * map, get the page, increment the use count and return it.
 97 */
 98#if IS_ENABLED(CONFIG_AGP)
 99static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
100{
101	struct drm_file *priv = vma->vm_file->private_data;
102	struct drm_device *dev = priv->minor->dev;
103	struct drm_local_map *map = NULL;
104	struct drm_map_list *r_list;
105	struct drm_hash_item *hash;
106
107	/*
108	 * Find the right map
109	 */
110	if (!dev->agp)
111		goto vm_fault_error;
112
113	if (!dev->agp || !dev->agp->cant_use_aperture)
114		goto vm_fault_error;
115
116	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
117		goto vm_fault_error;
118
119	r_list = drm_hash_entry(hash, struct drm_map_list, hash);
120	map = r_list->map;
121
122	if (map && map->type == _DRM_AGP) {
123		/*
124		 * Using vm_pgoff as a selector forces us to use this unusual
125		 * addressing scheme.
126		 */
127		resource_size_t offset = vmf->address - vma->vm_start;
 
128		resource_size_t baddr = map->offset + offset;
129		struct drm_agp_mem *agpmem;
130		struct page *page;
131
132#ifdef __alpha__
133		/*
134		 * Adjust to a bus-relative address
135		 */
136		baddr -= dev->hose->mem_space->start;
137#endif
138
139		/*
140		 * It's AGP memory - find the real physical page to map
141		 */
142		list_for_each_entry(agpmem, &dev->agp->memory, head) {
143			if (agpmem->bound <= baddr &&
144			    agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
145				break;
146		}
147
148		if (&agpmem->head == &dev->agp->memory)
149			goto vm_fault_error;
150
151		/*
152		 * Get the page, inc the use count, and return it
153		 */
154		offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
155		page = agpmem->memory->pages[offset];
156		get_page(page);
157		vmf->page = page;
158
159		DRM_DEBUG
160		    ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
161		     (unsigned long long)baddr,
162		     agpmem->memory->pages[offset],
163		     (unsigned long long)offset,
164		     page_count(page));
165		return 0;
166	}
167vm_fault_error:
168	return VM_FAULT_SIGBUS;	/* Disallow mremap */
169}
170#else
171static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
172{
173	return VM_FAULT_SIGBUS;
174}
175#endif
176
177/**
178 * \c nopage method for shared virtual memory.
179 *
180 * \param vma virtual memory area.
181 * \param address access address.
182 * \return pointer to the page structure.
183 *
184 * Get the mapping, find the real physical page to map, get the page, and
185 * return it.
186 */
187static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
188{
189	struct drm_local_map *map = vma->vm_private_data;
190	unsigned long offset;
191	unsigned long i;
192	struct page *page;
193
194	if (!map)
195		return VM_FAULT_SIGBUS;	/* Nothing allocated */
196
197	offset = vmf->address - vma->vm_start;
198	i = (unsigned long)map->handle + offset;
199	page = vmalloc_to_page((void *)i);
200	if (!page)
201		return VM_FAULT_SIGBUS;
202	get_page(page);
203	vmf->page = page;
204
205	DRM_DEBUG("shm_fault 0x%lx\n", offset);
206	return 0;
207}
208
209/**
210 * \c close method for shared virtual memory.
211 *
212 * \param vma virtual memory area.
213 *
214 * Deletes map information if we are the last
215 * person to close a mapping and it's not in the global maplist.
216 */
217static void drm_vm_shm_close(struct vm_area_struct *vma)
218{
219	struct drm_file *priv = vma->vm_file->private_data;
220	struct drm_device *dev = priv->minor->dev;
221	struct drm_vma_entry *pt, *temp;
222	struct drm_local_map *map;
223	struct drm_map_list *r_list;
224	int found_maps = 0;
225
226	DRM_DEBUG("0x%08lx,0x%08lx\n",
227		  vma->vm_start, vma->vm_end - vma->vm_start);
228
229	map = vma->vm_private_data;
230
231	mutex_lock(&dev->struct_mutex);
232	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
233		if (pt->vma->vm_private_data == map)
234			found_maps++;
235		if (pt->vma == vma) {
236			list_del(&pt->head);
237			kfree(pt);
238		}
239	}
240
241	/* We were the only map that was found */
242	if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
243		/* Check to see if we are in the maplist, if we are not, then
244		 * we delete this mappings information.
245		 */
246		found_maps = 0;
247		list_for_each_entry(r_list, &dev->maplist, head) {
248			if (r_list->map == map)
249				found_maps++;
250		}
251
252		if (!found_maps) {
253			drm_dma_handle_t dmah;
254
255			switch (map->type) {
256			case _DRM_REGISTERS:
257			case _DRM_FRAME_BUFFER:
258				arch_phys_wc_del(map->mtrr);
259				iounmap(map->handle);
260				break;
261			case _DRM_SHM:
262				vfree(map->handle);
263				break;
264			case _DRM_AGP:
265			case _DRM_SCATTER_GATHER:
266				break;
267			case _DRM_CONSISTENT:
268				dmah.vaddr = map->handle;
269				dmah.busaddr = map->offset;
270				dmah.size = map->size;
271				__drm_legacy_pci_free(dev, &dmah);
272				break;
273			}
274			kfree(map);
275		}
276	}
277	mutex_unlock(&dev->struct_mutex);
278}
279
280/**
281 * \c fault method for DMA virtual memory.
282 *
283 * \param vma virtual memory area.
284 * \param address access address.
285 * \return pointer to the page structure.
286 *
287 * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
288 */
289static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
290{
291	struct drm_file *priv = vma->vm_file->private_data;
292	struct drm_device *dev = priv->minor->dev;
293	struct drm_device_dma *dma = dev->dma;
294	unsigned long offset;
295	unsigned long page_nr;
296	struct page *page;
297
298	if (!dma)
299		return VM_FAULT_SIGBUS;	/* Error */
300	if (!dma->pagelist)
301		return VM_FAULT_SIGBUS;	/* Nothing allocated */
302
303	offset = vmf->address - vma->vm_start;
304					/* vm_[pg]off[set] should be 0 */
305	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
306	page = virt_to_page((void *)dma->pagelist[page_nr]);
307
308	get_page(page);
309	vmf->page = page;
310
311	DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
312	return 0;
313}
314
315/**
316 * \c fault method for scatter-gather virtual memory.
317 *
318 * \param vma virtual memory area.
319 * \param address access address.
320 * \return pointer to the page structure.
321 *
322 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
323 */
324static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
325{
326	struct drm_local_map *map = vma->vm_private_data;
327	struct drm_file *priv = vma->vm_file->private_data;
328	struct drm_device *dev = priv->minor->dev;
329	struct drm_sg_mem *entry = dev->sg;
330	unsigned long offset;
331	unsigned long map_offset;
332	unsigned long page_offset;
333	struct page *page;
334
335	if (!entry)
336		return VM_FAULT_SIGBUS;	/* Error */
337	if (!entry->pagelist)
338		return VM_FAULT_SIGBUS;	/* Nothing allocated */
339
340	offset = vmf->address - vma->vm_start;
341	map_offset = map->offset - (unsigned long)dev->sg->virtual;
342	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
343	page = entry->pagelist[page_offset];
344	get_page(page);
345	vmf->page = page;
346
347	return 0;
348}
349
350static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
351{
352	return drm_do_vm_fault(vma, vmf);
353}
354
355static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
356{
357	return drm_do_vm_shm_fault(vma, vmf);
358}
359
360static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
361{
362	return drm_do_vm_dma_fault(vma, vmf);
363}
364
365static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
366{
367	return drm_do_vm_sg_fault(vma, vmf);
368}
369
370/** AGP virtual memory operations */
371static const struct vm_operations_struct drm_vm_ops = {
372	.fault = drm_vm_fault,
373	.open = drm_vm_open,
374	.close = drm_vm_close,
375};
376
377/** Shared virtual memory operations */
378static const struct vm_operations_struct drm_vm_shm_ops = {
379	.fault = drm_vm_shm_fault,
380	.open = drm_vm_open,
381	.close = drm_vm_shm_close,
382};
383
384/** DMA virtual memory operations */
385static const struct vm_operations_struct drm_vm_dma_ops = {
386	.fault = drm_vm_dma_fault,
387	.open = drm_vm_open,
388	.close = drm_vm_close,
389};
390
391/** Scatter-gather virtual memory operations */
392static const struct vm_operations_struct drm_vm_sg_ops = {
393	.fault = drm_vm_sg_fault,
394	.open = drm_vm_open,
395	.close = drm_vm_close,
396};
397
398static void drm_vm_open_locked(struct drm_device *dev,
399			       struct vm_area_struct *vma)
 
 
 
 
 
 
 
 
400{
401	struct drm_vma_entry *vma_entry;
402
403	DRM_DEBUG("0x%08lx,0x%08lx\n",
404		  vma->vm_start, vma->vm_end - vma->vm_start);
405
406	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
407	if (vma_entry) {
408		vma_entry->vma = vma;
409		vma_entry->pid = current->pid;
410		list_add(&vma_entry->head, &dev->vmalist);
411	}
412}
 
413
414static void drm_vm_open(struct vm_area_struct *vma)
415{
416	struct drm_file *priv = vma->vm_file->private_data;
417	struct drm_device *dev = priv->minor->dev;
418
419	mutex_lock(&dev->struct_mutex);
420	drm_vm_open_locked(dev, vma);
421	mutex_unlock(&dev->struct_mutex);
422}
423
424static void drm_vm_close_locked(struct drm_device *dev,
425				struct vm_area_struct *vma)
426{
427	struct drm_vma_entry *pt, *temp;
428
429	DRM_DEBUG("0x%08lx,0x%08lx\n",
430		  vma->vm_start, vma->vm_end - vma->vm_start);
431
432	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
433		if (pt->vma == vma) {
434			list_del(&pt->head);
435			kfree(pt);
436			break;
437		}
438	}
439}
440
441/**
442 * \c close method for all virtual memory types.
443 *
444 * \param vma virtual memory area.
445 *
446 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
447 * free it.
448 */
449static void drm_vm_close(struct vm_area_struct *vma)
450{
451	struct drm_file *priv = vma->vm_file->private_data;
452	struct drm_device *dev = priv->minor->dev;
453
454	mutex_lock(&dev->struct_mutex);
455	drm_vm_close_locked(dev, vma);
456	mutex_unlock(&dev->struct_mutex);
457}
458
459/**
460 * mmap DMA memory.
461 *
462 * \param file_priv DRM file private.
463 * \param vma virtual memory area.
464 * \return zero on success or a negative number on failure.
465 *
466 * Sets the virtual memory area operations structure to vm_dma_ops, the file
467 * pointer, and calls vm_open().
468 */
469static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
470{
471	struct drm_file *priv = filp->private_data;
472	struct drm_device *dev;
473	struct drm_device_dma *dma;
474	unsigned long length = vma->vm_end - vma->vm_start;
475
476	dev = priv->minor->dev;
477	dma = dev->dma;
478	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
479		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
480
481	/* Length must match exact page count */
482	if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
483		return -EINVAL;
484	}
485
486	if (!capable(CAP_SYS_ADMIN) &&
487	    (dma->flags & _DRM_DMA_USE_PCI_RO)) {
488		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
489#if defined(__i386__) || defined(__x86_64__)
490		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
491#else
492		/* Ye gads this is ugly.  With more thought
493		   we could move this up higher and use
494		   `protection_map' instead.  */
495		vma->vm_page_prot =
496		    __pgprot(pte_val
497			     (pte_wrprotect
498			      (__pte(pgprot_val(vma->vm_page_prot)))));
499#endif
500	}
501
502	vma->vm_ops = &drm_vm_dma_ops;
503
504	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
505
506	drm_vm_open_locked(dev, vma);
507	return 0;
508}
509
510static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
511{
512#ifdef __alpha__
513	return dev->hose->dense_mem_base;
514#else
515	return 0;
516#endif
517}
518
519/**
520 * mmap DMA memory.
521 *
522 * \param file_priv DRM file private.
523 * \param vma virtual memory area.
524 * \return zero on success or a negative number on failure.
525 *
526 * If the virtual memory area has no offset associated with it then it's a DMA
527 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
528 * checks that the restricted flag is not set, sets the virtual memory operations
529 * according to the mapping type and remaps the pages. Finally sets the file
530 * pointer and calls vm_open().
531 */
532static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
533{
534	struct drm_file *priv = filp->private_data;
535	struct drm_device *dev = priv->minor->dev;
536	struct drm_local_map *map = NULL;
537	resource_size_t offset = 0;
538	struct drm_hash_item *hash;
539
540	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
541		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
542
543	if (!priv->authenticated)
544		return -EACCES;
545
546	/* We check for "dma". On Apple's UniNorth, it's valid to have
547	 * the AGP mapped at physical address 0
548	 * --BenH.
549	 */
550	if (!vma->vm_pgoff
551#if IS_ENABLED(CONFIG_AGP)
552	    && (!dev->agp
553		|| dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
554#endif
555	    )
556		return drm_mmap_dma(filp, vma);
557
558	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
559		DRM_ERROR("Could not find map\n");
560		return -EINVAL;
561	}
562
563	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
564	if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
565		return -EPERM;
566
567	/* Check for valid size. */
568	if (map->size < vma->vm_end - vma->vm_start)
569		return -EINVAL;
570
571	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
572		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
573#if defined(__i386__) || defined(__x86_64__)
574		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
575#else
576		/* Ye gads this is ugly.  With more thought
577		   we could move this up higher and use
578		   `protection_map' instead.  */
579		vma->vm_page_prot =
580		    __pgprot(pte_val
581			     (pte_wrprotect
582			      (__pte(pgprot_val(vma->vm_page_prot)))));
583#endif
584	}
585
586	switch (map->type) {
587#if !defined(__arm__)
588	case _DRM_AGP:
589		if (dev->agp && dev->agp->cant_use_aperture) {
590			/*
591			 * On some platforms we can't talk to bus dma address from the CPU, so for
592			 * memory of type DRM_AGP, we'll deal with sorting out the real physical
593			 * pages and mappings in fault()
594			 */
595#if defined(__powerpc__)
596			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
597#endif
598			vma->vm_ops = &drm_vm_ops;
599			break;
600		}
601		/* fall through to _DRM_FRAME_BUFFER... */
602#endif
603	case _DRM_FRAME_BUFFER:
604	case _DRM_REGISTERS:
605		offset = drm_core_get_reg_ofs(dev);
606		vma->vm_page_prot = drm_io_prot(map, vma);
607		if (io_remap_pfn_range(vma, vma->vm_start,
608				       (map->offset + offset) >> PAGE_SHIFT,
609				       vma->vm_end - vma->vm_start,
610				       vma->vm_page_prot))
611			return -EAGAIN;
612		DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
613			  " offset = 0x%llx\n",
614			  map->type,
615			  vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));
616
617		vma->vm_ops = &drm_vm_ops;
618		break;
619	case _DRM_CONSISTENT:
620		/* Consistent memory is really like shared memory. But
621		 * it's allocated in a different way, so avoid fault */
622		if (remap_pfn_range(vma, vma->vm_start,
623		    page_to_pfn(virt_to_page(map->handle)),
624		    vma->vm_end - vma->vm_start, vma->vm_page_prot))
625			return -EAGAIN;
626		vma->vm_page_prot = drm_dma_prot(map->type, vma);
627	/* fall through to _DRM_SHM */
628	case _DRM_SHM:
629		vma->vm_ops = &drm_vm_shm_ops;
630		vma->vm_private_data = (void *)map;
631		break;
632	case _DRM_SCATTER_GATHER:
633		vma->vm_ops = &drm_vm_sg_ops;
634		vma->vm_private_data = (void *)map;
635		vma->vm_page_prot = drm_dma_prot(map->type, vma);
636		break;
637	default:
638		return -EINVAL;	/* This should never happen. */
639	}
640	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
641
642	drm_vm_open_locked(dev, vma);
643	return 0;
644}
645
646int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma)
647{
648	struct drm_file *priv = filp->private_data;
649	struct drm_device *dev = priv->minor->dev;
650	int ret;
651
652	if (drm_device_is_unplugged(dev))
653		return -ENODEV;
654
655	mutex_lock(&dev->struct_mutex);
656	ret = drm_mmap_locked(filp, vma);
657	mutex_unlock(&dev->struct_mutex);
658
659	return ret;
660}
661EXPORT_SYMBOL(drm_legacy_mmap);
662
663void drm_legacy_vma_flush(struct drm_device *dev)
664{
665	struct drm_vma_entry *vma, *vma_temp;
666
667	/* Clear vma list (only needed for legacy drivers) */
668	list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
669		list_del(&vma->head);
670		kfree(vma);
671	}
672}