drivers/staging/gma500/psb_gem.c

   1 /*
   2  *  psb backlight interface
   3  *
   4  * Copyright (c) 2011, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Authors: Alan Cox
  20  *
  21  * TODO:
  22  *      -       we don't actually put GEM objects into the GART yet
  23  *      -       we need to work out if the MMU is relevant as well (eg for
  24  *              accelerated operations on a GEM object)
  25  *      -       cache coherency
  26  *
  27  * ie this is just an initial framework to get us going.
  28  */
  29
  30 #include <drm/drmP.h>
  31 #include <drm/drm.h>
  32 #include "psb_drm.h"
  33 #include "psb_drv.h"
  34
  35 int psb_gem_init_object(struct drm_gem_object *obj)
  36 {
  37         return -EINVAL;
  38 }
  39
  40 void psb_gem_free_object(struct drm_gem_object *obj)
  41 {
  42         struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
  43         psb_gtt_free_range(obj->dev, gtt);
  44         if (obj->map_list.map) {
  45                 /* Do things GEM should do for us */
  46                 struct drm_gem_mm *mm = obj->dev->mm_private;
  47                 struct drm_map_list *list = &obj->map_list;
  48                 drm_ht_remove_item(&mm->offset_hash, &list->hash);
  49                 drm_mm_put_block(list->file_offset_node);
  50                 kfree(list->map);
  51                 list->map = NULL;
  52         }
  53         drm_gem_object_release(obj);
  54 }
  55
  56 int psb_gem_get_aperture(struct drm_device *dev, void *data,
  57                                 struct drm_file *file)
  58 {
  59         return -EINVAL;
  60 }
  61
  62 /**
  63  *      psb_gem_create_mmap_offset      -       invent an mmap offset
  64  *      @obj: our object
  65  *
  66  *      This is basically doing by hand a pile of ugly crap which should
  67  *      be done automatically by the GEM library code but isn't
  68  */
  69 static int psb_gem_create_mmap_offset(struct drm_gem_object *obj)
  70 {
  71         struct drm_device *dev = obj->dev;
  72         struct drm_gem_mm *mm = dev->mm_private;
  73         struct drm_map_list *list;
  74         struct drm_local_map *map;
  75         int ret;
  76
  77         list = &obj->map_list;
  78         list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
  79         if (list->map == NULL)
  80                 return -ENOMEM;
  81         map = list->map;
  82         map->type = _DRM_GEM;
  83         map->size = obj->size;
  84         map->handle =obj;
  85
  86         list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
  87                                         obj->size / PAGE_SIZE, 0, 0);
  88         if (!list->file_offset_node) {
  89                 DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
  90                 ret = -ENOSPC;
  91                 goto free_it;
  92         }
  93         list->file_offset_node = drm_mm_get_block(list->file_offset_node,
  94                                         obj->size / PAGE_SIZE, 0);
  95         if (!list->file_offset_node) {
  96                 ret = -ENOMEM;
  97                 goto free_it;
  98         }
  99         list->hash.key = list->file_offset_node->start;
 100         ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
 101         if (ret) {
 102                 DRM_ERROR("failed to add to map hash\n");
 103                 goto free_mm;
 104         }
 105         return 0;
 106
 107 free_mm:
 108         drm_mm_put_block(list->file_offset_node);
 109 free_it:
 110         kfree(list->map);
 111         list->map = NULL;
 112         return ret;
 113 }
 114
 115 /**
 116  *      psb_gem_dumb_map_gtt    -       buffer mapping for dumb interface
 117  *      @file: our drm client file
 118  *      @dev: drm device
 119  *      @handle: GEM handle to the object (from dumb_create)
 120  *
 121  *      Do the necessary setup to allow the mapping of the frame buffer
 122  *      into user memory. We don't have to do much here at the moment.
 123  */
 124 int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev,
 125                          uint32_t handle, uint64_t *offset)
 126 {
 127         int ret = 0;
 128         struct drm_gem_object *obj;
 129
 130         if (!(dev->driver->driver_features & DRIVER_GEM))
 131                 return -ENODEV;
 132
 133         mutex_lock(&dev->struct_mutex);
 134
 135         /* GEM does all our handle to object mapping */
 136         obj = drm_gem_object_lookup(dev, file, handle);
 137         if (obj == NULL) {
 138                 ret = -ENOENT;
 139                 goto unlock;
 140         }
 141         /* What validation is needed here ? */
 142
 143         /* Make it mmapable */
 144         if (!obj->map_list.map) {
 145                 ret = psb_gem_create_mmap_offset(obj);
 146                 if (ret)
 147                         goto out;
 148         }
 149         /* GEM should really work out the hash offsets for us */
 150         *offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
 151 out:
 152         drm_gem_object_unreference(obj);
 153 unlock:
 154         mutex_unlock(&dev->struct_mutex);
 155         return ret;
 156 }
 157
 158 /**
 159  *      psb_gem_create          -       create a mappable object
 160  *      @file: the DRM file of the client
 161  *      @dev: our device
 162  *      @size: the size requested
 163  *      @handlep: returned handle (opaque number)
 164  *
 165  *      Create a GEM object, fill in the boilerplate and attach a handle to
 166  *      it so that userspace can speak about it. This does the core work
 167  *      for the various methods that do/will create GEM objects for things
 168  */
 169 static int psb_gem_create(struct drm_file *file,
 170         struct drm_device *dev, uint64_t size, uint32_t *handlep)
 171 {
 172         struct gtt_range *r;
 173         int ret;
 174         u32 handle;
 175
 176         size = roundup(size, PAGE_SIZE);
 177
 178         /* Allocate our object - for now a direct gtt range which is not
 179            stolen memory backed */
 180         r = psb_gtt_alloc_range(dev, size, "gem", 0);
 181         if (r == NULL)
 182                 return -ENOSPC;
 183         /* Initialize the extra goodies GEM needs to do all the hard work */
 184         if (drm_gem_object_init(dev, &r->gem, size) != 0) {
 185                 psb_gtt_free_range(dev, r);
 186                 /* GEM doesn't give an error code and we don't have an
 187                    EGEMSUCKS so make something up for now - FIXME */
 188                 return -ENOMEM;
 189         }
 190         /* Give the object a handle so we can carry it more easily */
 191         ret = drm_gem_handle_create(file, &r->gem, &handle);
 192         if (ret) {
 193                 drm_gem_object_release(&r->gem);
 194                 psb_gtt_free_range(dev, r);
 195                 return ret;
 196         }
 197         /* We have the initial and handle reference but need only one now */
 198         drm_gem_object_unreference(&r->gem);
 199         *handlep = handle;
 200         return 0;
 201 }
 202
 203 /**
 204  *      psb_gem_dumb_create     -       create a dumb buffer
 205  *      @drm_file: our client file
 206  *      @dev: our device
 207  *      @args: the requested arguments copied from userspace
 208  *
 209  *      Allocate a buffer suitable for use for a frame buffer of the
 210  *      form described by user space. Give userspace a handle by which
 211  *      to reference it.
 212  */
 213 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 214                         struct drm_mode_create_dumb *args)
 215 {
 216         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 217         args->size = args->pitch * args->height;
 218         return psb_gem_create(file, dev, args->size, &args->handle);
 219 }
 220
 221 /**
 222  *      psb_gem_dumb_destroy    -       destroy a dumb buffer
 223  *      @file: client file
 224  *      @dev: our DRM device
 225  *      @handle: the object handle
 226  *
 227  *      Destroy a handle that was created via psb_gem_dumb_create, at least
 228  *      we hope it was created that way. i915 seems to assume the caller
 229  *      does the checking but that might be worth review ! FIXME
 230  */
 231 int psb_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 232                         uint32_t handle)
 233 {
 234         /* No special work needed, drop the reference and see what falls out */
 235         return drm_gem_handle_delete(file, handle);
 236 }
 237
 238 /**
 239  *      psb_gem_fault           -       pagefault handler for GEM objects
 240  *      @vma: the VMA of the GEM object
 241  *      @vmf: fault detail
 242  *
 243  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 244  *      does most of the work for us including the actual map/unmap calls
 245  *      but we need to do the actual page work.
 246  *
 247  *      This code eventually needs to handle faulting objects in and out
 248  *      of the GART and repacking it when we run out of space. We can put
 249  *      that off for now and for our simple uses
 250  *
 251  *      The VMA was set up by GEM. In doing so it also ensured that the
 252  *      vma->vm_private_data points to the GEM object that is backing this
 253  *      mapping.
 254  */
 255 int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 256 {
 257         struct drm_gem_object *obj;
 258         struct gtt_range *r;
 259         int ret;
 260         unsigned long pfn;
 261         pgoff_t page_offset;
 262
 263         obj = vma->vm_private_data;     /* GEM object */
 264         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 265
 266         /* FIXME: Locking. We may also need to repack the GART sometimes */
 267
 268         /* Page relative to the VMA start */
 269         page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
 270                                 >> PAGE_SHIFT;
 271
 272         /* Bus address of the page is gart + object offset + page offset */
 273         /* Assumes gtt allocations are page aligned */
 274         pfn = (r->resource.start >> PAGE_SHIFT) + page_offset;
 275
 276         ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 277         switch (ret) {
 278         case 0:
 279         case -ERESTARTSYS:
 280         case -EINTR:
 281                 return VM_FAULT_NOPAGE;
 282         case -ENOMEM:
 283                 return VM_FAULT_OOM;
 284         default:
 285                 return VM_FAULT_SIGBUS;
 286         }
 287 }