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 and we don't have an
 124                    EGEMSUCKS so make something up for now - FIXME */
 125                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
 126                 return -ENOMEM;
 127         }
 128         /* Give the object a handle so we can carry it more easily */
 129         ret = drm_gem_handle_create(file, &r->gem, &handle);
 130         if (ret) {
 131                 dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
 132                                                         &r->gem, size);
 133                 drm_gem_object_release(&r->gem);
 134                 psb_gtt_free_range(dev, r);
 135                 return ret;
 136         }
 137         /* We have the initial and handle reference but need only one now */
 138         drm_gem_object_unreference(&r->gem);
 139         *handlep = handle;
 140         return 0;
 141 }
 142
 143 /**
 144  *      psb_gem_dumb_create     -       create a dumb buffer
 145  *      @drm_file: our client file
 146  *      @dev: our device
 147  *      @args: the requested arguments copied from userspace
 148  *
 149  *      Allocate a buffer suitable for use for a frame buffer of the
 150  *      form described by user space. Give userspace a handle by which
 151  *      to reference it.
 152  */
 153 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 154                         struct drm_mode_create_dumb *args)
 155 {
 156         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 157         args->size = args->pitch * args->height;
 158         return psb_gem_create(file, dev, args->size, &args->handle);
 159 }
 160
 161 /**
 162  *      psb_gem_dumb_destroy    -       destroy a dumb buffer
 163  *      @file: client file
 164  *      @dev: our DRM device
 165  *      @handle: the object handle
 166  *
 167  *      Destroy a handle that was created via psb_gem_dumb_create, at least
 168  *      we hope it was created that way. i915 seems to assume the caller
 169  *      does the checking but that might be worth review ! FIXME
 170  */
 171 int psb_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 172                         uint32_t handle)
 173 {
 174         /* No special work needed, drop the reference and see what falls out */
 175         return drm_gem_handle_delete(file, handle);
 176 }
 177
 178 /**
 179  *      psb_gem_fault           -       pagefault handler for GEM objects
 180  *      @vma: the VMA of the GEM object
 181  *      @vmf: fault detail
 182  *
 183  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 184  *      does most of the work for us including the actual map/unmap calls
 185  *      but we need to do the actual page work.
 186  *
 187  *      This code eventually needs to handle faulting objects in and out
 188  *      of the GTT and repacking it when we run out of space. We can put
 189  *      that off for now and for our simple uses
 190  *
 191  *      The VMA was set up by GEM. In doing so it also ensured that the
 192  *      vma->vm_private_data points to the GEM object that is backing this
 193  *      mapping.
 194  *
 195  *      FIXME
 196  */
 197 int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 198 {
 199         struct drm_gem_object *obj;
 200         struct gtt_range *r;
 201         int ret;
 202         unsigned long pfn;
 203         pgoff_t page_offset;
 204         struct drm_device *dev;
 205         struct drm_psb_private *dev_priv;
 206
 207         obj = vma->vm_private_data;     /* GEM object */
 208         dev = obj->dev;
 209         dev_priv = dev->dev_private;
 210
 211         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 212
 213         /* Make sure we don't parallel update on a fault, nor move or remove
 214            something from beneath our feet */
 215         mutex_lock(&dev->struct_mutex);
 216
 217         /* For now the mmap pins the object and it stays pinned. As things
 218            stand that will do us no harm */
 219         if (r->mmapping == 0) {
 220                 ret = psb_gtt_pin(r);
 221                 if (ret < 0) {
 222                         dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
 223                         goto fail;
 224                 }
 225                 r->mmapping = 1;
 226         }
 227
 228         /* Page relative to the VMA start - we must calculate this ourselves
 229            because vmf->pgoff is the fake GEM offset */
 230         page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
 231                                 >> PAGE_SHIFT;
 232
 233         /* CPU view of the page, don't go via the GART for CPU writes */
 234         if (r->stolen)
 235                 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 236         else
 237                 pfn = page_to_pfn(r->pages[page_offset]);
 238         ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 239
 240 fail:
 241         mutex_unlock(&dev->struct_mutex);
 242         switch (ret) {
 243         case 0:
 244         case -ERESTARTSYS:
 245         case -EINTR:
 246                 return VM_FAULT_NOPAGE;
 247         case -ENOMEM:
 248                 return VM_FAULT_OOM;
 249         default:
 250                 return VM_FAULT_SIGBUS;
 251         }
 252 }