drivers/gpu/drm/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 <drm/gma_drm.h>
  29 #include <drm/drm_vma_manager.h>
  30 #include "psb_drv.h"
  31
  32 void psb_gem_free_object(struct drm_gem_object *obj)
  33 {
  34         struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
  35
  36         /* Remove the list map if one is present */
  37         drm_gem_free_mmap_offset(obj);
  38         drm_gem_object_release(obj);
  39
  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         /* GEM does all our handle to object mapping */
  66         obj = drm_gem_object_lookup(dev, file, handle);
  67         if (obj == NULL)
  68                 return -ENOENT;
  69
  70         /* Make it mmapable */
  71         ret = drm_gem_create_mmap_offset(obj);
  72         if (ret)
  73                 goto out;
  74         *offset = drm_vma_node_offset_addr(&obj->vma_node);
  75 out:
  76         drm_gem_object_unreference_unlocked(obj);
  77         return ret;
  78 }
  79
  80 /**
  81  *      psb_gem_create          -       create a mappable object
  82  *      @file: the DRM file of the client
  83  *      @dev: our device
  84  *      @size: the size requested
  85  *      @handlep: returned handle (opaque number)
  86  *
  87  *      Create a GEM object, fill in the boilerplate and attach a handle to
  88  *      it so that userspace can speak about it. This does the core work
  89  *      for the various methods that do/will create GEM objects for things
  90  */
  91 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size,
  92                    u32 *handlep, int stolen, u32 align)
  93 {
  94         struct gtt_range *r;
  95         int ret;
  96         u32 handle;
  97
  98         size = roundup(size, PAGE_SIZE);
  99
 100         /* Allocate our object - for now a direct gtt range which is not
 101            stolen memory backed */
 102         r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE);
 103         if (r == NULL) {
 104                 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
 105                 return -ENOSPC;
 106         }
 107         /* Initialize the extra goodies GEM needs to do all the hard work */
 108         if (drm_gem_object_init(dev, &r->gem, size) != 0) {
 109                 psb_gtt_free_range(dev, r);
 110                 /* GEM doesn't give an error code so use -ENOMEM */
 111                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
 112                 return -ENOMEM;
 113         }
 114         /* Limit the object to 32bit mappings */
 115         mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
 116         /* Give the object a handle so we can carry it more easily */
 117         ret = drm_gem_handle_create(file, &r->gem, &handle);
 118         if (ret) {
 119                 dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
 120                                                         &r->gem, size);
 121                 drm_gem_object_release(&r->gem);
 122                 psb_gtt_free_range(dev, r);
 123                 return ret;
 124         }
 125         /* We have the initial and handle reference but need only one now */
 126         drm_gem_object_unreference_unlocked(&r->gem);
 127         *handlep = handle;
 128         return 0;
 129 }
 130
 131 /**
 132  *      psb_gem_dumb_create     -       create a dumb buffer
 133  *      @drm_file: our client file
 134  *      @dev: our device
 135  *      @args: the requested arguments copied from userspace
 136  *
 137  *      Allocate a buffer suitable for use for a frame buffer of the
 138  *      form described by user space. Give userspace a handle by which
 139  *      to reference it.
 140  */
 141 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 142                         struct drm_mode_create_dumb *args)
 143 {
 144         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 145         args->size = args->pitch * args->height;
 146         return psb_gem_create(file, dev, args->size, &args->handle, 0,
 147                               PAGE_SIZE);
 148 }
 149
 150 /**
 151  *      psb_gem_fault           -       pagefault handler for GEM objects
 152  *      @vma: the VMA of the GEM object
 153  *      @vmf: fault detail
 154  *
 155  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 156  *      does most of the work for us including the actual map/unmap calls
 157  *      but we need to do the actual page work.
 158  *
 159  *      This code eventually needs to handle faulting objects in and out
 160  *      of the GTT and repacking it when we run out of space. We can put
 161  *      that off for now and for our simple uses
 162  *
 163  *      The VMA was set up by GEM. In doing so it also ensured that the
 164  *      vma->vm_private_data points to the GEM object that is backing this
 165  *      mapping.
 166  */
 167 int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 168 {
 169         struct drm_gem_object *obj;
 170         struct gtt_range *r;
 171         int ret;
 172         unsigned long pfn;
 173         pgoff_t page_offset;
 174         struct drm_device *dev;
 175         struct drm_psb_private *dev_priv;
 176
 177         obj = vma->vm_private_data;     /* GEM object */
 178         dev = obj->dev;
 179         dev_priv = dev->dev_private;
 180
 181         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 182
 183         /* Make sure we don't parallel update on a fault, nor move or remove
 184            something from beneath our feet */
 185         mutex_lock(&dev_priv->mmap_mutex);
 186
 187         /* For now the mmap pins the object and it stays pinned. As things
 188            stand that will do us no harm */
 189         if (r->mmapping == 0) {
 190                 ret = psb_gtt_pin(r);
 191                 if (ret < 0) {
 192                         dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
 193                         goto fail;
 194                 }
 195                 r->mmapping = 1;
 196         }
 197
 198         /* Page relative to the VMA start - we must calculate this ourselves
 199            because vmf->pgoff is the fake GEM offset */
 200         page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
 201                                 >> PAGE_SHIFT;
 202
 203         /* CPU view of the page, don't go via the GART for CPU writes */
 204         if (r->stolen)
 205                 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 206         else
 207                 pfn = page_to_pfn(r->pages[page_offset]);
 208         ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 209
 210 fail:
 211         mutex_unlock(&dev_priv->mmap_mutex);
 212         switch (ret) {
 213         case 0:
 214         case -ERESTARTSYS:
 215         case -EINTR:
 216                 return VM_FAULT_NOPAGE;
 217         case -ENOMEM:
 218                 return VM_FAULT_OOM;
 219         default:
 220                 return VM_FAULT_SIGBUS;
 221         }
 222 }