/* * \file drm_vm.c * Memory mapping for DRM * * \author Rickard E. (Rik) Faith * \author Gareth Hughes */ /* * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com * * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include #if defined(__ia64__) #include #include #endif #include #include #include #include #include #include #include #include "drm_internal.h" #include "drm_legacy.h" struct drm_vma_entry { struct list_head head; struct vm_area_struct *vma; pid_t pid; }; static void drm_vm_open(struct vm_area_struct *vma); static void drm_vm_close(struct vm_area_struct *vma); static pgprot_t drm_io_prot(struct drm_local_map *map, struct vm_area_struct *vma) { pgprot_t tmp = vm_get_page_prot(vma->vm_flags); /* We don't want graphics memory to be mapped encrypted */ tmp = pgprot_decrypted(tmp); #if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) || \ defined(__mips__) if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING)) tmp = pgprot_noncached(tmp); else tmp = pgprot_writecombine(tmp); #elif defined(__ia64__) if (efi_range_is_wc(vma->vm_start, vma->vm_end - vma->vm_start)) tmp = pgprot_writecombine(tmp); else tmp = pgprot_noncached(tmp); #elif defined(__sparc__) || defined(__arm__) tmp = pgprot_noncached(tmp); #endif return tmp; } static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma) { pgprot_t tmp = vm_get_page_prot(vma->vm_flags); #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) tmp = pgprot_noncached_wc(tmp); #endif return tmp; } /* * \c fault method for AGP virtual memory. * * \param vma virtual memory area. * \param address access address. * \return pointer to the page structure. * * Find the right map and if it's AGP memory find the real physical page to * map, get the page, increment the use count and return it. */ #if IS_ENABLED(CONFIG_AGP) static vm_fault_t drm_vm_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; struct drm_local_map *map = NULL; struct drm_map_list *r_list; struct drm_hash_item *hash; /* * Find the right map */ if (!dev->agp) goto vm_fault_error; if (!dev->agp || !dev->agp->cant_use_aperture) goto vm_fault_error; if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) goto vm_fault_error; r_list = drm_hash_entry(hash, struct drm_map_list, hash); map = r_list->map; if (map && map->type == _DRM_AGP) { /* * Using vm_pgoff as a selector forces us to use this unusual * addressing scheme. */ resource_size_t offset = vmf->address - vma->vm_start; resource_size_t baddr = map->offset + offset; struct drm_agp_mem *agpmem; struct vm_page *page; #ifdef __alpha__ /* * Adjust to a bus-relative address */ baddr -= dev->hose->mem_space->start; #endif /* * It's AGP memory - find the real physical page to map */ list_for_each_entry(agpmem, &dev->agp->memory, head) { if (agpmem->bound <= baddr && agpmem->bound + agpmem->pages * PAGE_SIZE > baddr) break; } if (&agpmem->head == &dev->agp->memory) goto vm_fault_error; /* * Get the page, inc the use count, and return it */ offset = (baddr - agpmem->bound) >> PAGE_SHIFT; page = agpmem->memory->pages[offset]; get_page(page); vmf->page = page; DRM_DEBUG ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n", (unsigned long long)baddr, agpmem->memory->pages[offset], (unsigned long long)offset, page_count(page)); return 0; } vm_fault_error: return VM_FAULT_SIGBUS; /* Disallow mremap */ } #else static vm_fault_t drm_vm_fault(struct vm_fault *vmf) { return VM_FAULT_SIGBUS; } #endif /* * \c nopage method for shared virtual memory. * * \param vma virtual memory area. * \param address access address. * \return pointer to the page structure. * * Get the mapping, find the real physical page to map, get the page, and * return it. */ static vm_fault_t drm_vm_shm_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_local_map *map = vma->vm_private_data; unsigned long offset; unsigned long i; struct vm_page *page; if (!map) return VM_FAULT_SIGBUS; /* Nothing allocated */ offset = vmf->address - vma->vm_start; i = (unsigned long)map->handle + offset; page = vmalloc_to_page((void *)i); if (!page) return VM_FAULT_SIGBUS; get_page(page); vmf->page = page; DRM_DEBUG("shm_fault 0x%lx\n", offset); return 0; } /* * \c close method for shared virtual memory. * * \param vma virtual memory area. * * Deletes map information if we are the last * person to close a mapping and it's not in the global maplist. */ static void drm_vm_shm_close(struct vm_area_struct *vma) { struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; struct drm_vma_entry *pt, *temp; struct drm_local_map *map; struct drm_map_list *r_list; int found_maps = 0; DRM_DEBUG("0x%08lx,0x%08lx\n", vma->vm_start, vma->vm_end - vma->vm_start); map = vma->vm_private_data; mutex_lock(&dev->struct_mutex); list_for_each_entry_safe(pt, temp, &dev->vmalist, head) { if (pt->vma->vm_private_data == map) found_maps++; if (pt->vma == vma) { list_del(&pt->head); kfree(pt); } } /* We were the only map that was found */ if (found_maps == 1 && map->flags & _DRM_REMOVABLE) { /* Check to see if we are in the maplist, if we are not, then * we delete this mappings information. */ found_maps = 0; list_for_each_entry(r_list, &dev->maplist, head) { if (r_list->map == map) found_maps++; } if (!found_maps) { switch (map->type) { case _DRM_REGISTERS: case _DRM_FRAME_BUFFER: arch_phys_wc_del(map->mtrr); iounmap(map->handle); break; case _DRM_SHM: vfree(map->handle); break; case _DRM_AGP: case _DRM_SCATTER_GATHER: break; case _DRM_CONSISTENT: dma_free_coherent(&dev->pdev->dev, map->size, map->handle, map->offset); break; } kfree(map); } } mutex_unlock(&dev->struct_mutex); } /* * \c fault method for DMA virtual memory. * * \param address access address. * \return pointer to the page structure. * * Determine the page number from the page offset and get it from drm_device_dma::pagelist. */ static vm_fault_t drm_vm_dma_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; struct drm_device_dma *dma = dev->dma; unsigned long offset; unsigned long page_nr; struct vm_page *page; if (!dma) return VM_FAULT_SIGBUS; /* Error */ if (!dma->pagelist) return VM_FAULT_SIGBUS; /* Nothing allocated */ offset = vmf->address - vma->vm_start; /* vm_[pg]off[set] should be 0 */ page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */ page = virt_to_page((void *)dma->pagelist[page_nr]); get_page(page); vmf->page = page; DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr); return 0; } /* * \c fault method for scatter-gather virtual memory. * * \param address access address. * \return pointer to the page structure. * * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist. */ static vm_fault_t drm_vm_sg_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct drm_local_map *map = vma->vm_private_data; struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; struct drm_sg_mem *entry = dev->sg; unsigned long offset; unsigned long map_offset; unsigned long page_offset; struct vm_page *page; if (!entry) return VM_FAULT_SIGBUS; /* Error */ if (!entry->pagelist) return VM_FAULT_SIGBUS; /* Nothing allocated */ offset = vmf->address - vma->vm_start; map_offset = map->offset - (unsigned long)dev->sg->virtual; page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT); page = entry->pagelist[page_offset]; get_page(page); vmf->page = page; return 0; } /** AGP virtual memory operations */ static const struct vm_operations_struct drm_vm_ops = { .fault = drm_vm_fault, .open = drm_vm_open, .close = drm_vm_close, }; /** Shared virtual memory operations */ static const struct vm_operations_struct drm_vm_shm_ops = { .fault = drm_vm_shm_fault, .open = drm_vm_open, .close = drm_vm_shm_close, }; /** DMA virtual memory operations */ static const struct vm_operations_struct drm_vm_dma_ops = { .fault = drm_vm_dma_fault, .open = drm_vm_open, .close = drm_vm_close, }; /** Scatter-gather virtual memory operations */ static const struct vm_operations_struct drm_vm_sg_ops = { .fault = drm_vm_sg_fault, .open = drm_vm_open, .close = drm_vm_close, }; static void drm_vm_open_locked(struct drm_device *dev, struct vm_area_struct *vma) { struct drm_vma_entry *vma_entry; DRM_DEBUG("0x%08lx,0x%08lx\n", vma->vm_start, vma->vm_end - vma->vm_start); vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL); if (vma_entry) { vma_entry->vma = vma; vma_entry->pid = current->pid; list_add(&vma_entry->head, &dev->vmalist); } } static void drm_vm_open(struct vm_area_struct *vma) { struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; mutex_lock(&dev->struct_mutex); drm_vm_open_locked(dev, vma); mutex_unlock(&dev->struct_mutex); } static void drm_vm_close_locked(struct drm_device *dev, struct vm_area_struct *vma) { struct drm_vma_entry *pt, *temp; DRM_DEBUG("0x%08lx,0x%08lx\n", vma->vm_start, vma->vm_end - vma->vm_start); list_for_each_entry_safe(pt, temp, &dev->vmalist, head) { if (pt->vma == vma) { list_del(&pt->head); kfree(pt); break; } } } /* * \c close method for all virtual memory types. * * \param vma virtual memory area. * * Search the \p vma private data entry in drm_device::vmalist, unlink it, and * free it. */ static void drm_vm_close(struct vm_area_struct *vma) { struct drm_file *priv = vma->vm_file->private_data; struct drm_device *dev = priv->minor->dev; mutex_lock(&dev->struct_mutex); drm_vm_close_locked(dev, vma); mutex_unlock(&dev->struct_mutex); } /* * mmap DMA memory. * * \param file_priv DRM file private. * \param vma virtual memory area. * \return zero on success or a negative number on failure. * * Sets the virtual memory area operations structure to vm_dma_ops, the file * pointer, and calls vm_open(). */ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) { struct drm_file *priv = filp->private_data; struct drm_device *dev; struct drm_device_dma *dma; unsigned long length = vma->vm_end - vma->vm_start; dev = priv->minor->dev; dma = dev->dma; DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n", vma->vm_start, vma->vm_end, vma->vm_pgoff); /* Length must match exact page count */ if (!dma || (length >> PAGE_SHIFT) != dma->page_count) { return -EINVAL; } if (!capable(CAP_SYS_ADMIN) && (dma->flags & _DRM_DMA_USE_PCI_RO)) { vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); #if defined(__i386__) || defined(__x86_64__) pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; #else /* Ye gads this is ugly. With more thought we could move this up higher and use `protection_map' instead. */ vma->vm_page_prot = __pgprot(pte_val (pte_wrprotect (__pte(pgprot_val(vma->vm_page_prot))))); #endif } vma->vm_ops = &drm_vm_dma_ops; vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; drm_vm_open_locked(dev, vma); return 0; } static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev) { #ifdef __alpha__ return dev->hose->dense_mem_base; #else return 0; #endif } /* * mmap DMA memory. * * \param file_priv DRM file private. * \param vma virtual memory area. * \return zero on success or a negative number on failure. * * If the virtual memory area has no offset associated with it then it's a DMA * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist, * checks that the restricted flag is not set, sets the virtual memory operations * according to the mapping type and remaps the pages. Finally sets the file * pointer and calls vm_open(). */ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) { struct drm_file *priv = filp->private_data; struct drm_device *dev = priv->minor->dev; struct drm_local_map *map = NULL; resource_size_t offset = 0; struct drm_hash_item *hash; DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n", vma->vm_start, vma->vm_end, vma->vm_pgoff); if (!priv->authenticated) return -EACCES; /* We check for "dma". On Apple's UniNorth, it's valid to have * the AGP mapped at physical address 0 * --BenH. */ if (!vma->vm_pgoff #if IS_ENABLED(CONFIG_AGP) && (!dev->agp || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE) #endif ) return drm_mmap_dma(filp, vma); if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) { DRM_ERROR("Could not find map\n"); return -EINVAL; } map = drm_hash_entry(hash, struct drm_map_list, hash)->map; if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) return -EPERM; /* Check for valid size. */ if (map->size < vma->vm_end - vma->vm_start) return -EINVAL; if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) { vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE); #if defined(__i386__) || defined(__x86_64__) pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW; #else /* Ye gads this is ugly. With more thought we could move this up higher and use `protection_map' instead. */ vma->vm_page_prot = __pgprot(pte_val (pte_wrprotect (__pte(pgprot_val(vma->vm_page_prot))))); #endif } switch (map->type) { #if !defined(__arm__) case _DRM_AGP: if (dev->agp && dev->agp->cant_use_aperture) { /* * On some platforms we can't talk to bus dma address from the CPU, so for * memory of type DRM_AGP, we'll deal with sorting out the real physical * pages and mappings in fault() */ #if defined(__powerpc__) vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); #endif vma->vm_ops = &drm_vm_ops; break; } fallthrough; /* to _DRM_FRAME_BUFFER... */ #endif case _DRM_FRAME_BUFFER: case _DRM_REGISTERS: offset = drm_core_get_reg_ofs(dev); vma->vm_page_prot = drm_io_prot(map, vma); if (io_remap_pfn_range(vma, vma->vm_start, (map->offset + offset) >> PAGE_SHIFT, vma->vm_end - vma->vm_start, vma->vm_page_prot)) return -EAGAIN; DRM_DEBUG(" Type = %d; start = 0x%lx, end = 0x%lx," " offset = 0x%llx\n", map->type, vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset)); vma->vm_ops = &drm_vm_ops; break; case _DRM_CONSISTENT: /* Consistent memory is really like shared memory. But * it's allocated in a different way, so avoid fault */ if (remap_pfn_range(vma, vma->vm_start, page_to_pfn(virt_to_page(map->handle)), vma->vm_end - vma->vm_start, vma->vm_page_prot)) return -EAGAIN; vma->vm_page_prot = drm_dma_prot(map->type, vma); fallthrough; /* to _DRM_SHM */ case _DRM_SHM: vma->vm_ops = &drm_vm_shm_ops; vma->vm_private_data = (void *)map; break; case _DRM_SCATTER_GATHER: vma->vm_ops = &drm_vm_sg_ops; vma->vm_private_data = (void *)map; vma->vm_page_prot = drm_dma_prot(map->type, vma); break; default: return -EINVAL; /* This should never happen. */ } vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; drm_vm_open_locked(dev, vma); return 0; } int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma) { struct drm_file *priv = filp->private_data; struct drm_device *dev = priv->minor->dev; int ret; if (drm_dev_is_unplugged(dev)) return -ENODEV; mutex_lock(&dev->struct_mutex); ret = drm_mmap_locked(filp, vma); mutex_unlock(&dev->struct_mutex); return ret; } EXPORT_SYMBOL(drm_legacy_mmap); #if IS_ENABLED(CONFIG_DRM_LEGACY) void drm_legacy_vma_flush(struct drm_device *dev) { struct drm_vma_entry *vma, *vma_temp; /* Clear vma list (only needed for legacy drivers) */ list_for_each_entry_safe(vma, vma_temp, &dev->vmalist, head) { list_del(&vma->head); kfree(vma); } } #endif