drivers/staging/gma500/gem.c

   1 /*
   2  *  psb GEM 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 need to work out if the MMU is relevant (eg for
  23  *              accelerated operations on a GEM object)
  24  */
  25
  26 #include <drm/drmP.h>
  27 #include <drm/drm.h>
  28 #include "psb_drm.h"
  29 #include "psb_drv.h"
  30
  31 int psb_gem_init_object(struct drm_gem_object *obj)
  32 {
  33         return -EINVAL;
  34 }
  35
  36 void psb_gem_free_object(struct drm_gem_object *obj)
  37 {
  38         struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
  39         drm_gem_object_release_wrap(obj);
  40         /* This must occur last as it frees up the memory of the GEM object */
  41         psb_gtt_free_range(obj->dev, gtt);
  42 }
  43
  44 int psb_gem_get_aperture(struct drm_device *dev, void *data,
  45                                 struct drm_file *file)
  46 {
  47         return -EINVAL;
  48 }
  49
  50 /**
  51  *      psb_gem_dumb_map_gtt    -       buffer mapping for dumb interface
  52  *      @file: our drm client file
  53  *      @dev: drm device
  54  *      @handle: GEM handle to the object (from dumb_create)
  55  *
  56  *      Do the necessary setup to allow the mapping of the frame buffer
  57  *      into user memory. We don't have to do much here at the moment.
  58  */
  59 int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev,
  60                          uint32_t handle, uint64_t *offset)
  61 {
  62         int ret = 0;
  63         struct drm_gem_object *obj;
  64
  65         if (!(dev->driver->driver_features & DRIVER_GEM))
  66                 return -ENODEV;
  67
  68         mutex_lock(&dev->struct_mutex);
  69
  70         /* GEM does all our handle to object mapping */
  71         obj = drm_gem_object_lookup(dev, file, handle);
  72         if (obj == NULL) {
  73                 ret = -ENOENT;
  74                 goto unlock;
  75         }
  76         /* What validation is needed here ? */
  77
  78         /* Make it mmapable */
  79         if (!obj->map_list.map) {
  80                 ret = gem_create_mmap_offset(obj);
  81                 if (ret)
  82                         goto out;
  83         }
  84         /* GEM should really work out the hash offsets for us */
  85         *offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
  86 out:
  87         drm_gem_object_unreference(obj);
  88 unlock:
  89         mutex_unlock(&dev->struct_mutex);
  90         return ret;
  91 }
  92
  93 /**
  94  *      psb_gem_create          -       create a mappable object
  95  *      @file: the DRM file of the client
  96  *      @dev: our device
  97  *      @size: the size requested
  98  *      @handlep: returned handle (opaque number)
  99  *
 100  *      Create a GEM object, fill in the boilerplate and attach a handle to
 101  *      it so that userspace can speak about it. This does the core work
 102  *      for the various methods that do/will create GEM objects for things
 103  */
 104 static int psb_gem_create(struct drm_file *file,
 105         struct drm_device *dev, uint64_t size, uint32_t *handlep)
 106 {
 107         struct gtt_range *r;
 108         int ret;
 109         u32 handle;
 110
 111         size = roundup(size, PAGE_SIZE);
 112
 113         /* Allocate our object - for now a direct gtt range which is not
 114            stolen memory backed */
 115         r = psb_gtt_alloc_range(dev, size, "gem", 0);
 116         if (r == NULL) {
 117                 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
 118                 return -ENOSPC;
 119         }
 120         /* Initialize the extra goodies GEM needs to do all the hard work */
 121         if (drm_gem_object_init(dev, &r->gem, size) != 0) {
 122                 psb_gtt_free_range(dev, r);
 123                 /* GEM doesn't give an error code so use -ENOMEM */
 124                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
 125                 return -ENOMEM;
 126         }
 127         /* Give the object a handle so we can carry it more easily */
 128         ret = drm_gem_handle_create(file, &r->gem, &handle);
 129         if (ret) {
 130                 dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
 131                                                         &r->gem, size);
 132                 drm_gem_object_release(&r->gem);
 133                 psb_gtt_free_range(dev, r);
 134                 return ret;
 135         }
 136         /* We have the initial and handle reference but need only one now */
 137         drm_gem_object_unreference(&r->gem);
 138         *handlep = handle;
 139         return 0;
 140 }
 141
 142 /**
 143  *      psb_gem_dumb_create     -       create a dumb buffer
 144  *      @drm_file: our client file
 145  *      @dev: our device
 146  *      @args: the requested arguments copied from userspace
 147  *
 148  *      Allocate a buffer suitable for use for a frame buffer of the
 149  *      form described by user space. Give userspace a handle by which
 150  *      to reference it.
 151  */
 152 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 153                         struct drm_mode_create_dumb *args)
 154 {
 155         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 156         args->size = args->pitch * args->height;
 157         return psb_gem_create(file, dev, args->size, &args->handle);
 158 }
 159
 160 /**
 161  *      psb_gem_dumb_destroy    -       destroy a dumb buffer
 162  *      @file: client file
 163  *      @dev: our DRM device
 164  *      @handle: the object handle
 165  *
 166  *      Destroy a handle that was created via psb_gem_dumb_create, at least
 167  *      we hope it was created that way. i915 seems to assume the caller
 168  *      does the checking but that might be worth review ! FIXME
 169  */
 170 int psb_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 171                         uint32_t handle)
 172 {
 173         /* No special work needed, drop the reference and see what falls out */
 174         return drm_gem_handle_delete(file, handle);
 175 }
 176
 177 /**
 178  *      psb_gem_fault           -       pagefault handler for GEM objects
 179  *      @vma: the VMA of the GEM object
 180  *      @vmf: fault detail
 181  *
 182  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 183  *      does most of the work for us including the actual map/unmap calls
 184  *      but we need to do the actual page work.
 185  *
 186  *      This code eventually needs to handle faulting objects in and out
 187  *      of the GTT and repacking it when we run out of space. We can put
 188  *      that off for now and for our simple uses
 189  *
 190  *      The VMA was set up by GEM. In doing so it also ensured that the
 191  *      vma->vm_private_data points to the GEM object that is backing this
 192  *      mapping.
 193  */
 194 int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 195 {
 196         struct drm_gem_object *obj;
 197         struct gtt_range *r;
 198         int ret;
 199         unsigned long pfn;
 200         pgoff_t page_offset;
 201         struct drm_device *dev;
 202         struct drm_psb_private *dev_priv;
 203
 204         obj = vma->vm_private_data;     /* GEM object */
 205         dev = obj->dev;
 206         dev_priv = dev->dev_private;
 207
 208         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 209
 210         /* Make sure we don't parallel update on a fault, nor move or remove
 211            something from beneath our feet */
 212         mutex_lock(&dev->struct_mutex);
 213
 214         /* For now the mmap pins the object and it stays pinned. As things
 215            stand that will do us no harm */
 216         if (r->mmapping == 0) {
 217                 ret = psb_gtt_pin(r);
 218                 if (ret < 0) {
 219                         dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
 220                         goto fail;
 221                 }
 222                 r->mmapping = 1;
 223         }
 224
 225         /* Page relative to the VMA start - we must calculate this ourselves
 226            because vmf->pgoff is the fake GEM offset */
 227         page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
 228                                 >> PAGE_SHIFT;
 229
 230         /* CPU view of the page, don't go via the GART for CPU writes */
 231         if (r->stolen)
 232                 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 233         else
 234                 pfn = page_to_pfn(r->pages[page_offset]);
 235         ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 236
 237 fail:
 238         mutex_unlock(&dev->struct_mutex);
 239         switch (ret) {
 240         case 0:
 241         case -ERESTARTSYS:
 242         case -EINTR:
 243                 return VM_FAULT_NOPAGE;
 244         case -ENOMEM:
 245                 return VM_FAULT_OOM;
 246         default:
 247                 return VM_FAULT_SIGBUS;
 248         }
 249 }
 250
 251 static int psb_gem_create_stolen(struct drm_file *file, struct drm_device *dev,
 252                                                 int size, u32 *handle)
 253 {
 254         struct gtt_range *gtt = psb_gtt_alloc_range(dev, size, "gem", 1);
 255         if (gtt == NULL)
 256                 return -ENOMEM;
 257         if (drm_gem_private_object_init(dev, &gtt->gem, size) != 0)
 258                 goto free_gtt;
 259         if (drm_gem_handle_create(file, &gtt->gem, handle) == 0)
 260                 return 0;
 261 free_gtt:
 262         psb_gtt_free_range(dev, gtt);
 263         return -ENOMEM;
 264 }
 265
 266 /*
 267  *      GEM interfaces for our specific client
 268  */
 269 int psb_gem_create_ioctl(struct drm_device *dev, void *data,
 270                                         struct drm_file *file)
 271 {
 272         struct drm_psb_gem_create *args = data;
 273         int ret;
 274         if (args->flags & PSB_GEM_CREATE_STOLEN) {
 275                 ret = psb_gem_create_stolen(file, dev, args->size,
 276                                                         &args->handle);
 277                 if (ret == 0)
 278                         return 0;
 279                 /* Fall throguh */
 280                 args->flags &= ~PSB_GEM_CREATE_STOLEN;
 281         }
 282         return psb_gem_create(file, dev, args->size, &args->handle);
 283 }
 284
 285 int psb_gem_mmap_ioctl(struct drm_device *dev, void *data,
 286                                         struct drm_file *file)
 287 {
 288         struct drm_psb_gem_mmap *args = data;
 289         return dev->driver->dumb_map_offset(file, dev,
 290                                                 args->handle, &args->offset);
 291 }
 292