FreeBSD/Linux Kernel Cross Reference
sys/dev/drm/drm_vm.c

     /*-
      * Copyright 2003 Eric Anholt
      * 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
     * ERIC ANHOLT 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 <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    /** @file drm_vm.c
     * Support code for mmaping of DRM maps.
     */
    
    #include "dev/drm/drmP.h"
    #include "dev/drm/drm.h"
    
    int drm_mmap(struct cdev *kdev, vm_ooffset_t offset, vm_paddr_t *paddr,
        int prot, vm_memattr_t *memattr)
    {
            struct drm_device *dev = drm_get_device_from_kdev(kdev);
            struct drm_file *file_priv = NULL;
            drm_local_map_t *map;
            enum drm_map_type type;
            vm_paddr_t phys;
            int error;
    
            /* d_mmap gets called twice, we can only reference file_priv during
             * the first call.  We need to assume that if error is EBADF the
             * call was succesful and the client is authenticated.
             */
            error = devfs_get_cdevpriv((void **)&file_priv);
            if (error == ENOENT) {
                    DRM_ERROR("Could not find authenticator!\n");
                    return EINVAL;
            }
    
            if (file_priv && !file_priv->authenticated)
                    return EACCES;
    
            DRM_DEBUG("called with offset %016jx\n", offset);
            if (dev->dma && offset < ptoa(dev->dma->page_count)) {
                    drm_device_dma_t *dma = dev->dma;
    
                    DRM_SPINLOCK(&dev->dma_lock);
    
                    if (dma->pagelist != NULL) {
                            unsigned long page = offset >> PAGE_SHIFT;
                            unsigned long phys = dma->pagelist[page];
    
                            DRM_SPINUNLOCK(&dev->dma_lock);
                            *paddr = phys;
                            return 0;
                    } else {
                            DRM_SPINUNLOCK(&dev->dma_lock);
                            return -1;
                    }
            }
    
            /* A sequential search of a linked list is
               fine here because: 1) there will only be
               about 5-10 entries in the list and, 2) a
               DRI client only has to do this mapping
               once, so it doesn't have to be optimized
               for performance, even if the list was a
               bit longer.
            */
            DRM_LOCK();
            TAILQ_FOREACH(map, &dev->maplist, link) {
                    if (offset >> DRM_MAP_HANDLE_SHIFT ==
                        (unsigned long)map->handle >> DRM_MAP_HANDLE_SHIFT)
                            break;
            }
    
            if (map == NULL) {
                    DRM_DEBUG("Can't find map, request offset = %016jx\n", offset);
                    TAILQ_FOREACH(map, &dev->maplist, link) {
                            DRM_DEBUG("map offset = %016lx, handle = %016lx\n",
                                map->offset, (unsigned long)map->handle);
                    }
                    DRM_UNLOCK();
                    return -1;
            }
           if (((map->flags & _DRM_RESTRICTED) && !DRM_SUSER(DRM_CURPROC))) {
                   DRM_UNLOCK();
                   DRM_DEBUG("restricted map\n");
                   return -1;
           }
           type = map->type;
           DRM_UNLOCK();
   
           offset = offset & ((1ULL << DRM_MAP_HANDLE_SHIFT) - 1);
   
           switch (type) {
           case _DRM_FRAME_BUFFER:
           case _DRM_AGP:
                   *memattr = VM_MEMATTR_WRITE_COMBINING;
                   /* FALLTHROUGH */
           case _DRM_REGISTERS:
                   phys = map->offset + offset;
                   break;
           case _DRM_SCATTER_GATHER:
                   *memattr = VM_MEMATTR_WRITE_COMBINING;
                   /* FALLTHROUGH */
           case _DRM_CONSISTENT:
           case _DRM_SHM:
                   phys = vtophys((char *)map->virtual + offset);
                   break;
           default:
                   DRM_ERROR("bad map type %d\n", type);
                   return -1;      /* This should never happen. */
           }
   
           *paddr = phys;
           return 0;
   }
   

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