LXR linux/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
  32void 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
  44int 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 */
  61int 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_unreference_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 */
 111int 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 */
 137int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 138{
 139        struct drm_gem_object *obj;
 140        struct gtt_range *r;
 141        int ret;
 142        unsigned long pfn;
 143        pgoff_t page_offset;
 144        struct drm_device *dev;
 145        struct drm_psb_private *dev_priv;
 146
 147        obj = vma->vm_private_data;     /* GEM object */
 148        dev = obj->dev;
 149        dev_priv = dev->dev_private;
 150
 151        r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 152
 153        /* Make sure we don't parallel update on a fault, nor move or remove
 154           something from beneath our feet */
 155        mutex_lock(&dev_priv->mmap_mutex);
 156
 157        /* For now the mmap pins the object and it stays pinned. As things
 158           stand that will do us no harm */
 159        if (r->mmapping == 0) {
 160                ret = psb_gtt_pin(r);
 161                if (ret < 0) {
 162                        dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
 163                        goto fail;
 164                }
 165                r->mmapping = 1;
 166        }
 167
 168        /* Page relative to the VMA start - we must calculate this ourselves
 169           because vmf->pgoff is the fake GEM offset */
 170        page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
 171                                >> PAGE_SHIFT;
 172
 173        /* CPU view of the page, don't go via the GART for CPU writes */
 174        if (r->stolen)
 175                pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 176        else
 177                pfn = page_to_pfn(r->pages[page_offset]);
 178        ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 179
 180fail:
 181        mutex_unlock(&dev_priv->mmap_mutex);
 182        switch (ret) {
 183        case 0:
 184        case -ERESTARTSYS:
 185        case -EINTR:
 186                return VM_FAULT_NOPAGE;
 187        case -ENOMEM:
 188                return VM_FAULT_OOM;
 189        default:
 190                return VM_FAULT_SIGBUS;
 191        }
 192}
 193