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v5.4
  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 <linux/export.h>
 37#include <linux/pci.h>
 38#include <linux/seq_file.h>
 39#include <linux/vmalloc.h>
 40
 41#if defined(__ia64__)
 42#include <linux/efi.h>
 43#include <linux/slab.h>
 44#endif
 45#include <linux/mem_encrypt.h>
 46
 47#include <asm/pgtable.h>
 48
 49#include <drm/drm_agpsupport.h>
 50#include <drm/drm_device.h>
 51#include <drm/drm_drv.h>
 52#include <drm/drm_file.h>
 53#include <drm/drm_framebuffer.h>
 54#include <drm/drm_gem.h>
 55#include <drm/drm_print.h>
 56
 57#include "drm_internal.h"
 58#include "drm_legacy.h"
 59
 60struct drm_vma_entry {
 61	struct list_head head;
 62	struct vm_area_struct *vma;
 63	pid_t pid;
 64};
 65
 66static void drm_vm_open(struct vm_area_struct *vma);
 67static void drm_vm_close(struct vm_area_struct *vma);
 68
 69static pgprot_t drm_io_prot(struct drm_local_map *map,
 70			    struct vm_area_struct *vma)
 71{
 72	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 73
 74	/* We don't want graphics memory to be mapped encrypted */
 75	tmp = pgprot_decrypted(tmp);
 76
 77#if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) || \
 78    defined(__mips__)
 79	if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))
 80		tmp = pgprot_noncached(tmp);
 81	else
 82		tmp = pgprot_writecombine(tmp);
 
 
 
 
 83#elif defined(__ia64__)
 84	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
 85				    vma->vm_start))
 86		tmp = pgprot_writecombine(tmp);
 87	else
 88		tmp = pgprot_noncached(tmp);
 89#elif defined(__sparc__) || defined(__arm__)
 90	tmp = pgprot_noncached(tmp);
 91#endif
 92	return tmp;
 93}
 94
 95static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
 96{
 97	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 98
 99#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
100	tmp = pgprot_noncached_wc(tmp);
101#endif
102	return tmp;
103}
104
105/**
106 * \c fault method for AGP virtual memory.
107 *
108 * \param vma virtual memory area.
109 * \param address access address.
110 * \return pointer to the page structure.
111 *
112 * Find the right map and if it's AGP memory find the real physical page to
113 * map, get the page, increment the use count and return it.
114 */
115#if IS_ENABLED(CONFIG_AGP)
116static vm_fault_t drm_vm_fault(struct vm_fault *vmf)
117{
118	struct vm_area_struct *vma = vmf->vma;
119	struct drm_file *priv = vma->vm_file->private_data;
120	struct drm_device *dev = priv->minor->dev;
121	struct drm_local_map *map = NULL;
122	struct drm_map_list *r_list;
123	struct drm_hash_item *hash;
124
125	/*
126	 * Find the right map
127	 */
128	if (!dev->agp)
129		goto vm_fault_error;
130
131	if (!dev->agp || !dev->agp->cant_use_aperture)
132		goto vm_fault_error;
133
134	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
135		goto vm_fault_error;
136
137	r_list = drm_hash_entry(hash, struct drm_map_list, hash);
138	map = r_list->map;
139
140	if (map && map->type == _DRM_AGP) {
141		/*
142		 * Using vm_pgoff as a selector forces us to use this unusual
143		 * addressing scheme.
144		 */
145		resource_size_t offset = vmf->address - vma->vm_start;
 
146		resource_size_t baddr = map->offset + offset;
147		struct drm_agp_mem *agpmem;
148		struct page *page;
149
150#ifdef __alpha__
151		/*
152		 * Adjust to a bus-relative address
153		 */
154		baddr -= dev->hose->mem_space->start;
155#endif
156
157		/*
158		 * It's AGP memory - find the real physical page to map
159		 */
160		list_for_each_entry(agpmem, &dev->agp->memory, head) {
161			if (agpmem->bound <= baddr &&
162			    agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
163				break;
164		}
165
166		if (&agpmem->head == &dev->agp->memory)
167			goto vm_fault_error;
168
169		/*
170		 * Get the page, inc the use count, and return it
171		 */
172		offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
173		page = agpmem->memory->pages[offset];
174		get_page(page);
175		vmf->page = page;
176
177		DRM_DEBUG
178		    ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
179		     (unsigned long long)baddr,
180		     agpmem->memory->pages[offset],
181		     (unsigned long long)offset,
182		     page_count(page));
183		return 0;
184	}
185vm_fault_error:
186	return VM_FAULT_SIGBUS;	/* Disallow mremap */
187}
188#else
189static vm_fault_t drm_vm_fault(struct vm_fault *vmf)
190{
191	return VM_FAULT_SIGBUS;
192}
193#endif
194
195/**
196 * \c nopage method for shared virtual memory.
197 *
198 * \param vma virtual memory area.
199 * \param address access address.
200 * \return pointer to the page structure.
201 *
202 * Get the mapping, find the real physical page to map, get the page, and
203 * return it.
204 */
205static vm_fault_t drm_vm_shm_fault(struct vm_fault *vmf)
206{
207	struct vm_area_struct *vma = vmf->vma;
208	struct drm_local_map *map = vma->vm_private_data;
209	unsigned long offset;
210	unsigned long i;
211	struct page *page;
212
213	if (!map)
214		return VM_FAULT_SIGBUS;	/* Nothing allocated */
215
216	offset = vmf->address - vma->vm_start;
217	i = (unsigned long)map->handle + offset;
218	page = vmalloc_to_page((void *)i);
219	if (!page)
220		return VM_FAULT_SIGBUS;
221	get_page(page);
222	vmf->page = page;
223
224	DRM_DEBUG("shm_fault 0x%lx\n", offset);
225	return 0;
226}
227
228/**
229 * \c close method for shared virtual memory.
230 *
231 * \param vma virtual memory area.
232 *
233 * Deletes map information if we are the last
234 * person to close a mapping and it's not in the global maplist.
235 */
236static void drm_vm_shm_close(struct vm_area_struct *vma)
237{
238	struct drm_file *priv = vma->vm_file->private_data;
239	struct drm_device *dev = priv->minor->dev;
240	struct drm_vma_entry *pt, *temp;
241	struct drm_local_map *map;
242	struct drm_map_list *r_list;
243	int found_maps = 0;
244
245	DRM_DEBUG("0x%08lx,0x%08lx\n",
246		  vma->vm_start, vma->vm_end - vma->vm_start);
247
248	map = vma->vm_private_data;
249
250	mutex_lock(&dev->struct_mutex);
251	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
252		if (pt->vma->vm_private_data == map)
253			found_maps++;
254		if (pt->vma == vma) {
255			list_del(&pt->head);
256			kfree(pt);
257		}
258	}
259
260	/* We were the only map that was found */
261	if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
262		/* Check to see if we are in the maplist, if we are not, then
263		 * we delete this mappings information.
264		 */
265		found_maps = 0;
266		list_for_each_entry(r_list, &dev->maplist, head) {
267			if (r_list->map == map)
268				found_maps++;
269		}
270
271		if (!found_maps) {
272			drm_dma_handle_t dmah;
273
274			switch (map->type) {
275			case _DRM_REGISTERS:
276			case _DRM_FRAME_BUFFER:
277				arch_phys_wc_del(map->mtrr);
278				iounmap(map->handle);
279				break;
280			case _DRM_SHM:
281				vfree(map->handle);
282				break;
283			case _DRM_AGP:
284			case _DRM_SCATTER_GATHER:
285				break;
286			case _DRM_CONSISTENT:
287				dmah.vaddr = map->handle;
288				dmah.busaddr = map->offset;
289				dmah.size = map->size;
290				__drm_legacy_pci_free(dev, &dmah);
291				break;
292			}
293			kfree(map);
294		}
295	}
296	mutex_unlock(&dev->struct_mutex);
297}
298
299/**
300 * \c fault method for DMA virtual memory.
301 *
 
302 * \param address access address.
303 * \return pointer to the page structure.
304 *
305 * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
306 */
307static vm_fault_t drm_vm_dma_fault(struct vm_fault *vmf)
308{
309	struct vm_area_struct *vma = vmf->vma;
310	struct drm_file *priv = vma->vm_file->private_data;
311	struct drm_device *dev = priv->minor->dev;
312	struct drm_device_dma *dma = dev->dma;
313	unsigned long offset;
314	unsigned long page_nr;
315	struct page *page;
316
317	if (!dma)
318		return VM_FAULT_SIGBUS;	/* Error */
319	if (!dma->pagelist)
320		return VM_FAULT_SIGBUS;	/* Nothing allocated */
321
322	offset = vmf->address - vma->vm_start;
323					/* vm_[pg]off[set] should be 0 */
324	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
325	page = virt_to_page((void *)dma->pagelist[page_nr]);
326
327	get_page(page);
328	vmf->page = page;
329
330	DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
331	return 0;
332}
333
334/**
335 * \c fault method for scatter-gather virtual memory.
336 *
 
337 * \param address access address.
338 * \return pointer to the page structure.
339 *
340 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
341 */
342static vm_fault_t drm_vm_sg_fault(struct vm_fault *vmf)
343{
344	struct vm_area_struct *vma = vmf->vma;
345	struct drm_local_map *map = vma->vm_private_data;
346	struct drm_file *priv = vma->vm_file->private_data;
347	struct drm_device *dev = priv->minor->dev;
348	struct drm_sg_mem *entry = dev->sg;
349	unsigned long offset;
350	unsigned long map_offset;
351	unsigned long page_offset;
352	struct page *page;
353
354	if (!entry)
355		return VM_FAULT_SIGBUS;	/* Error */
356	if (!entry->pagelist)
357		return VM_FAULT_SIGBUS;	/* Nothing allocated */
358
359	offset = vmf->address - vma->vm_start;
360	map_offset = map->offset - (unsigned long)dev->sg->virtual;
361	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
362	page = entry->pagelist[page_offset];
363	get_page(page);
364	vmf->page = page;
365
366	return 0;
367}
368
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
369/** AGP virtual memory operations */
370static const struct vm_operations_struct drm_vm_ops = {
371	.fault = drm_vm_fault,
372	.open = drm_vm_open,
373	.close = drm_vm_close,
374};
375
376/** Shared virtual memory operations */
377static const struct vm_operations_struct drm_vm_shm_ops = {
378	.fault = drm_vm_shm_fault,
379	.open = drm_vm_open,
380	.close = drm_vm_shm_close,
381};
382
383/** DMA virtual memory operations */
384static const struct vm_operations_struct drm_vm_dma_ops = {
385	.fault = drm_vm_dma_fault,
386	.open = drm_vm_open,
387	.close = drm_vm_close,
388};
389
390/** Scatter-gather virtual memory operations */
391static const struct vm_operations_struct drm_vm_sg_ops = {
392	.fault = drm_vm_sg_fault,
393	.open = drm_vm_open,
394	.close = drm_vm_close,
395};
396
397static void drm_vm_open_locked(struct drm_device *dev,
398			       struct vm_area_struct *vma)
 
 
 
 
 
 
 
 
399{
400	struct drm_vma_entry *vma_entry;
401
402	DRM_DEBUG("0x%08lx,0x%08lx\n",
403		  vma->vm_start, vma->vm_end - vma->vm_start);
404
405	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
406	if (vma_entry) {
407		vma_entry->vma = vma;
408		vma_entry->pid = current->pid;
409		list_add(&vma_entry->head, &dev->vmalist);
410	}
411}
 
412
413static void drm_vm_open(struct vm_area_struct *vma)
414{
415	struct drm_file *priv = vma->vm_file->private_data;
416	struct drm_device *dev = priv->minor->dev;
417
418	mutex_lock(&dev->struct_mutex);
419	drm_vm_open_locked(dev, vma);
420	mutex_unlock(&dev->struct_mutex);
421}
422
423static void drm_vm_close_locked(struct drm_device *dev,
424				struct vm_area_struct *vma)
425{
426	struct drm_vma_entry *pt, *temp;
427
428	DRM_DEBUG("0x%08lx,0x%08lx\n",
429		  vma->vm_start, vma->vm_end - vma->vm_start);
430
431	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
432		if (pt->vma == vma) {
433			list_del(&pt->head);
434			kfree(pt);
435			break;
436		}
437	}
438}
439
440/**
441 * \c close method for all virtual memory types.
442 *
443 * \param vma virtual memory area.
444 *
445 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
446 * free it.
447 */
448static void drm_vm_close(struct vm_area_struct *vma)
449{
450	struct drm_file *priv = vma->vm_file->private_data;
451	struct drm_device *dev = priv->minor->dev;
452
453	mutex_lock(&dev->struct_mutex);
454	drm_vm_close_locked(dev, vma);
455	mutex_unlock(&dev->struct_mutex);
456}
457
458/**
459 * mmap DMA memory.
460 *
461 * \param file_priv DRM file private.
462 * \param vma virtual memory area.
463 * \return zero on success or a negative number on failure.
464 *
465 * Sets the virtual memory area operations structure to vm_dma_ops, the file
466 * pointer, and calls vm_open().
467 */
468static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
469{
470	struct drm_file *priv = filp->private_data;
471	struct drm_device *dev;
472	struct drm_device_dma *dma;
473	unsigned long length = vma->vm_end - vma->vm_start;
474
475	dev = priv->minor->dev;
476	dma = dev->dma;
477	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
478		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
479
480	/* Length must match exact page count */
481	if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
482		return -EINVAL;
483	}
484
485	if (!capable(CAP_SYS_ADMIN) &&
486	    (dma->flags & _DRM_DMA_USE_PCI_RO)) {
487		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
488#if defined(__i386__) || defined(__x86_64__)
489		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
490#else
491		/* Ye gads this is ugly.  With more thought
492		   we could move this up higher and use
493		   `protection_map' instead.  */
494		vma->vm_page_prot =
495		    __pgprot(pte_val
496			     (pte_wrprotect
497			      (__pte(pgprot_val(vma->vm_page_prot)))));
498#endif
499	}
500
501	vma->vm_ops = &drm_vm_dma_ops;
502
503	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
504
505	drm_vm_open_locked(dev, vma);
506	return 0;
507}
508
509static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
510{
511#ifdef __alpha__
512	return dev->hose->dense_mem_base;
513#else
514	return 0;
515#endif
516}
517
518/**
519 * mmap DMA memory.
520 *
521 * \param file_priv DRM file private.
522 * \param vma virtual memory area.
523 * \return zero on success or a negative number on failure.
524 *
525 * If the virtual memory area has no offset associated with it then it's a DMA
526 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
527 * checks that the restricted flag is not set, sets the virtual memory operations
528 * according to the mapping type and remaps the pages. Finally sets the file
529 * pointer and calls vm_open().
530 */
531static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
532{
533	struct drm_file *priv = filp->private_data;
534	struct drm_device *dev = priv->minor->dev;
535	struct drm_local_map *map = NULL;
536	resource_size_t offset = 0;
537	struct drm_hash_item *hash;
538
539	DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
540		  vma->vm_start, vma->vm_end, vma->vm_pgoff);
541
542	if (!priv->authenticated)
543		return -EACCES;
544
545	/* We check for "dma". On Apple's UniNorth, it's valid to have
546	 * the AGP mapped at physical address 0
547	 * --BenH.
548	 */
549	if (!vma->vm_pgoff
550#if IS_ENABLED(CONFIG_AGP)
551	    && (!dev->agp
552		|| dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
553#endif
554	    )
555		return drm_mmap_dma(filp, vma);
556
557	if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
558		DRM_ERROR("Could not find map\n");
559		return -EINVAL;
560	}
561
562	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
563	if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
564		return -EPERM;
565
566	/* Check for valid size. */
567	if (map->size < vma->vm_end - vma->vm_start)
568		return -EINVAL;
569
570	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
571		vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
572#if defined(__i386__) || defined(__x86_64__)
573		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
574#else
575		/* Ye gads this is ugly.  With more thought
576		   we could move this up higher and use
577		   `protection_map' instead.  */
578		vma->vm_page_prot =
579		    __pgprot(pte_val
580			     (pte_wrprotect
581			      (__pte(pgprot_val(vma->vm_page_prot)))));
582#endif
583	}
584
585	switch (map->type) {
586#if !defined(__arm__)
587	case _DRM_AGP:
588		if (dev->agp && dev->agp->cant_use_aperture) {
589			/*
590			 * On some platforms we can't talk to bus dma address from the CPU, so for
591			 * memory of type DRM_AGP, we'll deal with sorting out the real physical
592			 * pages and mappings in fault()
593			 */
594#if defined(__powerpc__)
595			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
596#endif
597			vma->vm_ops = &drm_vm_ops;
598			break;
599		}
 
600#endif
601		/* fall through - to _DRM_FRAME_BUFFER... */
602	case _DRM_FRAME_BUFFER:
603	case _DRM_REGISTERS:
604		offset = drm_core_get_reg_ofs(dev);
605		vma->vm_page_prot = drm_io_prot(map, vma);
606		if (io_remap_pfn_range(vma, vma->vm_start,
607				       (map->offset + offset) >> PAGE_SHIFT,
608				       vma->vm_end - vma->vm_start,
609				       vma->vm_page_prot))
610			return -EAGAIN;
611		DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
612			  " offset = 0x%llx\n",
613			  map->type,
614			  vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));
615
616		vma->vm_ops = &drm_vm_ops;
617		break;
618	case _DRM_CONSISTENT:
619		/* Consistent memory is really like shared memory. But
620		 * it's allocated in a different way, so avoid fault */
621		if (remap_pfn_range(vma, vma->vm_start,
622		    page_to_pfn(virt_to_page(map->handle)),
623		    vma->vm_end - vma->vm_start, vma->vm_page_prot))
624			return -EAGAIN;
625		vma->vm_page_prot = drm_dma_prot(map->type, vma);
626		/* fall through - to _DRM_SHM */
627	case _DRM_SHM:
628		vma->vm_ops = &drm_vm_shm_ops;
629		vma->vm_private_data = (void *)map;
630		break;
631	case _DRM_SCATTER_GATHER:
632		vma->vm_ops = &drm_vm_sg_ops;
633		vma->vm_private_data = (void *)map;
634		vma->vm_page_prot = drm_dma_prot(map->type, vma);
635		break;
636	default:
637		return -EINVAL;	/* This should never happen. */
638	}
639	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
640
641	drm_vm_open_locked(dev, vma);
642	return 0;
643}
644
645int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma)
646{
647	struct drm_file *priv = filp->private_data;
648	struct drm_device *dev = priv->minor->dev;
649	int ret;
650
651	if (drm_dev_is_unplugged(dev))
652		return -ENODEV;
653
654	mutex_lock(&dev->struct_mutex);
655	ret = drm_mmap_locked(filp, vma);
656	mutex_unlock(&dev->struct_mutex);
657
658	return ret;
659}
660EXPORT_SYMBOL(drm_legacy_mmap);
661
662#if IS_ENABLED(CONFIG_DRM_LEGACY)
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}
673#endif
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);