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_create          -       create a mappable object
  52  *      @file: the DRM file of the client
  53  *      @dev: our device
  54  *      @size: the size requested
  55  *      @handlep: returned handle (opaque number)
  56  *
  57  *      Create a GEM object, fill in the boilerplate and attach a handle to
  58  *      it so that userspace can speak about it. This does the core work
  59  *      for the various methods that do/will create GEM objects for things
  60  */
  61 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size,
  62                    u32 *handlep, int stolen, u32 align)
  63 {
  64         struct gtt_range *r;
  65         int ret;
  66         u32 handle;
  67
  68         size = roundup(size, PAGE_SIZE);
  69
  70         /* Allocate our object - for now a direct gtt range which is not
  71            stolen memory backed */
  72         r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE);
  73         if (r == NULL) {
  74                 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
  75                 return -ENOSPC;
  76         }
  77         /* Initialize the extra goodies GEM needs to do all the hard work */
  78         if (drm_gem_object_init(dev, &r->gem, size) != 0) {
  79                 psb_gtt_free_range(dev, r);
  80                 /* GEM doesn't give an error code so use -ENOMEM */
  81                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
  82                 return -ENOMEM;
  83         }
  84         /* Limit the object to 32bit mappings */
  85         mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
  86         /* Give the object a handle so we can carry it more easily */
  87         ret = drm_gem_handle_create(file, &r->gem, &handle);
  88         if (ret) {
  89                 dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
  90                                                         &r->gem, size);
  91                 drm_gem_object_release(&r->gem);
  92                 psb_gtt_free_range(dev, r);
  93                 return ret;
  94         }
  95         /* We have the initial and handle reference but need only one now */
  96         drm_gem_object_put_unlocked(&r->gem);
  97         *handlep = handle;
  98         return 0;
  99 }
 100
 101 /**
 102  *      psb_gem_dumb_create     -       create a dumb buffer
 103  *      @drm_file: our client file
 104  *      @dev: our device
 105  *      @args: the requested arguments copied from userspace
 106  *
 107  *      Allocate a buffer suitable for use for a frame buffer of the
 108  *      form described by user space. Give userspace a handle by which
 109  *      to reference it.
 110  */
 111 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 112                         struct drm_mode_create_dumb *args)
 113 {
 114         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 115         args->size = args->pitch * args->height;
 116         return psb_gem_create(file, dev, args->size, &args->handle, 0,
 117                               PAGE_SIZE);
 118 }
 119
 120 /**
 121  *      psb_gem_fault           -       pagefault handler for GEM objects
 122  *      @vma: the VMA of the GEM object
 123  *      @vmf: fault detail
 124  *
 125  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 126  *      does most of the work for us including the actual map/unmap calls
 127  *      but we need to do the actual page work.
 128  *
 129  *      This code eventually needs to handle faulting objects in and out
 130  *      of the GTT and repacking it when we run out of space. We can put
 131  *      that off for now and for our simple uses
 132  *
 133  *      The VMA was set up by GEM. In doing so it also ensured that the
 134  *      vma->vm_private_data points to the GEM object that is backing this
 135  *      mapping.
 136  */
 137 vm_fault_t psb_gem_fault(struct vm_fault *vmf)
 138 {
 139         struct vm_area_struct *vma = vmf->vma;
 140         struct drm_gem_object *obj;
 141         struct gtt_range *r;
 142         int err;
 143         vm_fault_t ret;
 144         unsigned long pfn;
 145         pgoff_t page_offset;
 146         struct drm_device *dev;
 147         struct drm_psb_private *dev_priv;
 148
 149         obj = vma->vm_private_data;     /* GEM object */
 150         dev = obj->dev;
 151         dev_priv = dev->dev_private;
 152
 153         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 154
 155         /* Make sure we don't parallel update on a fault, nor move or remove
 156            something from beneath our feet */
 157         mutex_lock(&dev_priv->mmap_mutex);
 158
 159         /* For now the mmap pins the object and it stays pinned. As things
 160            stand that will do us no harm */
 161         if (r->mmapping == 0) {
 162                 err = psb_gtt_pin(r);
 163                 if (err < 0) {
 164                         dev_err(dev->dev, "gma500: pin failed: %d\n", err);
 165                         ret = vmf_error(err);
 166                         goto fail;
 167                 }
 168                 r->mmapping = 1;
 169         }
 170
 171         /* Page relative to the VMA start - we must calculate this ourselves
 172            because vmf->pgoff is the fake GEM offset */
 173         page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 174
 175         /* CPU view of the page, don't go via the GART for CPU writes */
 176         if (r->stolen)
 177                 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 178         else
 179                 pfn = page_to_pfn(r->pages[page_offset]);
 180         ret = vmf_insert_pfn(vma, vmf->address, pfn);
 181 fail:
 182         mutex_unlock(&dev_priv->mmap_mutex);
 183
 184         return ret;
 185 }