3 * Memory mapping for DRM
12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
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:
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
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
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32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
36 #include <linux/export.h>
37 #include <linux/pci.h>
38 #include <linux/seq_file.h>
39 #include <linux/vmalloc.h>
40 #include <linux/pgtable.h>
43 #include <linux/efi.h>
44 #include <linux/slab.h>
46 #include <linux/mem_encrypt.h>
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_print.h>
56 #include "drm_internal.h"
57 #include "drm_legacy.h"
59 struct drm_vma_entry {
60 struct list_head head;
61 struct vm_area_struct *vma;
65 static void drm_vm_open(struct vm_area_struct *vma);
66 static void drm_vm_close(struct vm_area_struct *vma);
68 static pgprot_t drm_io_prot(struct drm_local_map *map,
69 struct vm_area_struct *vma)
71 pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
73 /* We don't want graphics memory to be mapped encrypted */
74 tmp = pgprot_decrypted(tmp);
76 #if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) || \
78 if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))
79 tmp = pgprot_noncached(tmp);
81 tmp = pgprot_writecombine(tmp);
82 #elif defined(__ia64__)
83 if (efi_range_is_wc(vma->vm_start, vma->vm_end -
85 tmp = pgprot_writecombine(tmp);
87 tmp = pgprot_noncached(tmp);
88 #elif defined(__sparc__) || defined(__arm__)
89 tmp = pgprot_noncached(tmp);
94 static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
96 pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
98 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
99 tmp = pgprot_noncached_wc(tmp);
105 * \c fault method for AGP virtual memory.
107 * \param vma virtual memory area.
108 * \param address access address.
109 * \return pointer to the page structure.
111 * Find the right map and if it's AGP memory find the real physical page to
112 * map, get the page, increment the use count and return it.
114 #if IS_ENABLED(CONFIG_AGP)
115 static vm_fault_t drm_vm_fault(struct vm_fault *vmf)
117 struct vm_area_struct *vma = vmf->vma;
118 struct drm_file *priv = vma->vm_file->private_data;
119 struct drm_device *dev = priv->minor->dev;
120 struct drm_local_map *map = NULL;
121 struct drm_map_list *r_list;
122 struct drm_hash_item *hash;
130 if (!dev->agp || !dev->agp->cant_use_aperture)
133 if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
136 r_list = drm_hash_entry(hash, struct drm_map_list, hash);
139 if (map && map->type == _DRM_AGP) {
141 * Using vm_pgoff as a selector forces us to use this unusual
144 resource_size_t offset = vmf->address - vma->vm_start;
145 resource_size_t baddr = map->offset + offset;
146 struct drm_agp_mem *agpmem;
151 * Adjust to a bus-relative address
153 baddr -= dev->hose->mem_space->start;
157 * It's AGP memory - find the real physical page to map
159 list_for_each_entry(agpmem, &dev->agp->memory, head) {
160 if (agpmem->bound <= baddr &&
161 agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
165 if (&agpmem->head == &dev->agp->memory)
169 * Get the page, inc the use count, and return it
171 offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
172 page = agpmem->memory->pages[offset];
177 ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
178 (unsigned long long)baddr,
179 agpmem->memory->pages[offset],
180 (unsigned long long)offset,
185 return VM_FAULT_SIGBUS; /* Disallow mremap */
188 static vm_fault_t drm_vm_fault(struct vm_fault *vmf)
190 return VM_FAULT_SIGBUS;
195 * \c nopage method for shared virtual memory.
197 * \param vma virtual memory area.
198 * \param address access address.
199 * \return pointer to the page structure.
201 * Get the mapping, find the real physical page to map, get the page, and
204 static vm_fault_t drm_vm_shm_fault(struct vm_fault *vmf)
206 struct vm_area_struct *vma = vmf->vma;
207 struct drm_local_map *map = vma->vm_private_data;
208 unsigned long offset;
213 return VM_FAULT_SIGBUS; /* Nothing allocated */
215 offset = vmf->address - vma->vm_start;
216 i = (unsigned long)map->handle + offset;
217 page = vmalloc_to_page((void *)i);
219 return VM_FAULT_SIGBUS;
223 DRM_DEBUG("shm_fault 0x%lx\n", offset);
228 * \c close method for shared virtual memory.
230 * \param vma virtual memory area.
232 * Deletes map information if we are the last
233 * person to close a mapping and it's not in the global maplist.
235 static void drm_vm_shm_close(struct vm_area_struct *vma)
237 struct drm_file *priv = vma->vm_file->private_data;
238 struct drm_device *dev = priv->minor->dev;
239 struct drm_vma_entry *pt, *temp;
240 struct drm_local_map *map;
241 struct drm_map_list *r_list;
244 DRM_DEBUG("0x%08lx,0x%08lx\n",
245 vma->vm_start, vma->vm_end - vma->vm_start);
247 map = vma->vm_private_data;
249 mutex_lock(&dev->struct_mutex);
250 list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
251 if (pt->vma->vm_private_data == map)
253 if (pt->vma == vma) {
259 /* We were the only map that was found */
260 if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
261 /* Check to see if we are in the maplist, if we are not, then
262 * we delete this mappings information.
265 list_for_each_entry(r_list, &dev->maplist, head) {
266 if (r_list->map == map)
273 case _DRM_FRAME_BUFFER:
274 arch_phys_wc_del(map->mtrr);
275 iounmap(map->handle);
281 case _DRM_SCATTER_GATHER:
283 case _DRM_CONSISTENT:
284 dma_free_coherent(&dev->pdev->dev,
293 mutex_unlock(&dev->struct_mutex);
297 * \c fault method for DMA virtual memory.
299 * \param address access address.
300 * \return pointer to the page structure.
302 * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
304 static vm_fault_t drm_vm_dma_fault(struct vm_fault *vmf)
306 struct vm_area_struct *vma = vmf->vma;
307 struct drm_file *priv = vma->vm_file->private_data;
308 struct drm_device *dev = priv->minor->dev;
309 struct drm_device_dma *dma = dev->dma;
310 unsigned long offset;
311 unsigned long page_nr;
315 return VM_FAULT_SIGBUS; /* Error */
317 return VM_FAULT_SIGBUS; /* Nothing allocated */
319 offset = vmf->address - vma->vm_start;
320 /* vm_[pg]off[set] should be 0 */
321 page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
322 page = virt_to_page((void *)dma->pagelist[page_nr]);
327 DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
332 * \c fault method for scatter-gather virtual memory.
334 * \param address access address.
335 * \return pointer to the page structure.
337 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
339 static vm_fault_t drm_vm_sg_fault(struct vm_fault *vmf)
341 struct vm_area_struct *vma = vmf->vma;
342 struct drm_local_map *map = vma->vm_private_data;
343 struct drm_file *priv = vma->vm_file->private_data;
344 struct drm_device *dev = priv->minor->dev;
345 struct drm_sg_mem *entry = dev->sg;
346 unsigned long offset;
347 unsigned long map_offset;
348 unsigned long page_offset;
352 return VM_FAULT_SIGBUS; /* Error */
353 if (!entry->pagelist)
354 return VM_FAULT_SIGBUS; /* Nothing allocated */
356 offset = vmf->address - vma->vm_start;
357 map_offset = map->offset - (unsigned long)dev->sg->virtual;
358 page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
359 page = entry->pagelist[page_offset];
366 /** AGP virtual memory operations */
367 static const struct vm_operations_struct drm_vm_ops = {
368 .fault = drm_vm_fault,
370 .close = drm_vm_close,
373 /** Shared virtual memory operations */
374 static const struct vm_operations_struct drm_vm_shm_ops = {
375 .fault = drm_vm_shm_fault,
377 .close = drm_vm_shm_close,
380 /** DMA virtual memory operations */
381 static const struct vm_operations_struct drm_vm_dma_ops = {
382 .fault = drm_vm_dma_fault,
384 .close = drm_vm_close,
387 /** Scatter-gather virtual memory operations */
388 static const struct vm_operations_struct drm_vm_sg_ops = {
389 .fault = drm_vm_sg_fault,
391 .close = drm_vm_close,
394 static void drm_vm_open_locked(struct drm_device *dev,
395 struct vm_area_struct *vma)
397 struct drm_vma_entry *vma_entry;
399 DRM_DEBUG("0x%08lx,0x%08lx\n",
400 vma->vm_start, vma->vm_end - vma->vm_start);
402 vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
404 vma_entry->vma = vma;
405 vma_entry->pid = current->pid;
406 list_add(&vma_entry->head, &dev->vmalist);
410 static void drm_vm_open(struct vm_area_struct *vma)
412 struct drm_file *priv = vma->vm_file->private_data;
413 struct drm_device *dev = priv->minor->dev;
415 mutex_lock(&dev->struct_mutex);
416 drm_vm_open_locked(dev, vma);
417 mutex_unlock(&dev->struct_mutex);
420 static void drm_vm_close_locked(struct drm_device *dev,
421 struct vm_area_struct *vma)
423 struct drm_vma_entry *pt, *temp;
425 DRM_DEBUG("0x%08lx,0x%08lx\n",
426 vma->vm_start, vma->vm_end - vma->vm_start);
428 list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
429 if (pt->vma == vma) {
438 * \c close method for all virtual memory types.
440 * \param vma virtual memory area.
442 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
445 static void drm_vm_close(struct vm_area_struct *vma)
447 struct drm_file *priv = vma->vm_file->private_data;
448 struct drm_device *dev = priv->minor->dev;
450 mutex_lock(&dev->struct_mutex);
451 drm_vm_close_locked(dev, vma);
452 mutex_unlock(&dev->struct_mutex);
458 * \param file_priv DRM file private.
459 * \param vma virtual memory area.
460 * \return zero on success or a negative number on failure.
462 * Sets the virtual memory area operations structure to vm_dma_ops, the file
463 * pointer, and calls vm_open().
465 static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
467 struct drm_file *priv = filp->private_data;
468 struct drm_device *dev;
469 struct drm_device_dma *dma;
470 unsigned long length = vma->vm_end - vma->vm_start;
472 dev = priv->minor->dev;
474 DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
475 vma->vm_start, vma->vm_end, vma->vm_pgoff);
477 /* Length must match exact page count */
478 if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
482 if (!capable(CAP_SYS_ADMIN) &&
483 (dma->flags & _DRM_DMA_USE_PCI_RO)) {
484 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
485 #if defined(__i386__) || defined(__x86_64__)
486 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
488 /* Ye gads this is ugly. With more thought
489 we could move this up higher and use
490 `protection_map' instead. */
494 (__pte(pgprot_val(vma->vm_page_prot)))));
498 vma->vm_ops = &drm_vm_dma_ops;
500 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
502 drm_vm_open_locked(dev, vma);
506 static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
509 return dev->hose->dense_mem_base;
518 * \param file_priv DRM file private.
519 * \param vma virtual memory area.
520 * \return zero on success or a negative number on failure.
522 * If the virtual memory area has no offset associated with it then it's a DMA
523 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
524 * checks that the restricted flag is not set, sets the virtual memory operations
525 * according to the mapping type and remaps the pages. Finally sets the file
526 * pointer and calls vm_open().
528 static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
530 struct drm_file *priv = filp->private_data;
531 struct drm_device *dev = priv->minor->dev;
532 struct drm_local_map *map = NULL;
533 resource_size_t offset = 0;
534 struct drm_hash_item *hash;
536 DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
537 vma->vm_start, vma->vm_end, vma->vm_pgoff);
539 if (!priv->authenticated)
542 /* We check for "dma". On Apple's UniNorth, it's valid to have
543 * the AGP mapped at physical address 0
547 #if IS_ENABLED(CONFIG_AGP)
549 || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
552 return drm_mmap_dma(filp, vma);
554 if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
555 DRM_ERROR("Could not find map\n");
559 map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
560 if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
563 /* Check for valid size. */
564 if (map->size < vma->vm_end - vma->vm_start)
567 if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
568 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
569 #if defined(__i386__) || defined(__x86_64__)
570 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
572 /* Ye gads this is ugly. With more thought
573 we could move this up higher and use
574 `protection_map' instead. */
578 (__pte(pgprot_val(vma->vm_page_prot)))));
583 #if !defined(__arm__)
585 if (dev->agp && dev->agp->cant_use_aperture) {
587 * On some platforms we can't talk to bus dma address from the CPU, so for
588 * memory of type DRM_AGP, we'll deal with sorting out the real physical
589 * pages and mappings in fault()
591 #if defined(__powerpc__)
592 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
594 vma->vm_ops = &drm_vm_ops;
597 fallthrough; /* to _DRM_FRAME_BUFFER... */
599 case _DRM_FRAME_BUFFER:
601 offset = drm_core_get_reg_ofs(dev);
602 vma->vm_page_prot = drm_io_prot(map, vma);
603 if (io_remap_pfn_range(vma, vma->vm_start,
604 (map->offset + offset) >> PAGE_SHIFT,
605 vma->vm_end - vma->vm_start,
608 DRM_DEBUG(" Type = %d; start = 0x%lx, end = 0x%lx,"
609 " offset = 0x%llx\n",
611 vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));
613 vma->vm_ops = &drm_vm_ops;
615 case _DRM_CONSISTENT:
616 /* Consistent memory is really like shared memory. But
617 * it's allocated in a different way, so avoid fault */
618 if (remap_pfn_range(vma, vma->vm_start,
619 page_to_pfn(virt_to_page(map->handle)),
620 vma->vm_end - vma->vm_start, vma->vm_page_prot))
622 vma->vm_page_prot = drm_dma_prot(map->type, vma);
623 fallthrough; /* to _DRM_SHM */
625 vma->vm_ops = &drm_vm_shm_ops;
626 vma->vm_private_data = (void *)map;
628 case _DRM_SCATTER_GATHER:
629 vma->vm_ops = &drm_vm_sg_ops;
630 vma->vm_private_data = (void *)map;
631 vma->vm_page_prot = drm_dma_prot(map->type, vma);
634 return -EINVAL; /* This should never happen. */
636 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
638 drm_vm_open_locked(dev, vma);
642 int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma)
644 struct drm_file *priv = filp->private_data;
645 struct drm_device *dev = priv->minor->dev;
648 if (drm_dev_is_unplugged(dev))
651 mutex_lock(&dev->struct_mutex);
652 ret = drm_mmap_locked(filp, vma);
653 mutex_unlock(&dev->struct_mutex);
657 EXPORT_SYMBOL(drm_legacy_mmap);
659 #if IS_ENABLED(CONFIG_DRM_LEGACY)
660 void drm_legacy_vma_flush(struct drm_device *dev)
662 struct drm_vma_entry *vma, *vma_temp;
664 /* Clear vma list (only needed for legacy drivers) */
665 list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) {
666 list_del(&vma->head);