drivers/gpu/drm/gma500/gem.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  psb GEM interface
   4  *
   5  * Copyright (c) 2011, Intel Corporation.
   6  *
   7  * Authors: Alan Cox
   8  *
   9  * TODO:
  10  *      -       we need to work out if the MMU is relevant (eg for
  11  *              accelerated operations on a GEM object)
  12  */
  13
  14 #include <linux/pagemap.h>
  15
  16 #include <drm/drm.h>
  17 #include <drm/drm_vma_manager.h>
  18
  19 #include "psb_drv.h"
  20
  21 void psb_gem_free_object(struct drm_gem_object *obj)
  22 {
  23         struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
  24
  25         /* Remove the list map if one is present */
  26         drm_gem_free_mmap_offset(obj);
  27         drm_gem_object_release(obj);
  28
  29         /* This must occur last as it frees up the memory of the GEM object */
  30         psb_gtt_free_range(obj->dev, gtt);
  31 }
  32
  33 int psb_gem_get_aperture(struct drm_device *dev, void *data,
  34                                 struct drm_file *file)
  35 {
  36         return -EINVAL;
  37 }
  38
  39 /**
  40  *      psb_gem_create          -       create a mappable object
  41  *      @file: the DRM file of the client
  42  *      @dev: our device
  43  *      @size: the size requested
  44  *      @handlep: returned handle (opaque number)
  45  *
  46  *      Create a GEM object, fill in the boilerplate and attach a handle to
  47  *      it so that userspace can speak about it. This does the core work
  48  *      for the various methods that do/will create GEM objects for things
  49  */
  50 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size,
  51                    u32 *handlep, int stolen, u32 align)
  52 {
  53         struct gtt_range *r;
  54         int ret;
  55         u32 handle;
  56
  57         size = roundup(size, PAGE_SIZE);
  58
  59         /* Allocate our object - for now a direct gtt range which is not
  60            stolen memory backed */
  61         r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE);
  62         if (r == NULL) {
  63                 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
  64                 return -ENOSPC;
  65         }
  66         /* Initialize the extra goodies GEM needs to do all the hard work */
  67         if (drm_gem_object_init(dev, &r->gem, size) != 0) {
  68                 psb_gtt_free_range(dev, r);
  69                 /* GEM doesn't give an error code so use -ENOMEM */
  70                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
  71                 return -ENOMEM;
  72         }
  73         /* Limit the object to 32bit mappings */
  74         mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
  75         /* Give the object a handle so we can carry it more easily */
  76         ret = drm_gem_handle_create(file, &r->gem, &handle);
  77         if (ret) {
  78                 dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
  79                                                         &r->gem, size);
  80                 drm_gem_object_release(&r->gem);
  81                 psb_gtt_free_range(dev, r);
  82                 return ret;
  83         }
  84         /* We have the initial and handle reference but need only one now */
  85         drm_gem_object_put_unlocked(&r->gem);
  86         *handlep = handle;
  87         return 0;
  88 }
  89
  90 /**
  91  *      psb_gem_dumb_create     -       create a dumb buffer
  92  *      @drm_file: our client file
  93  *      @dev: our device
  94  *      @args: the requested arguments copied from userspace
  95  *
  96  *      Allocate a buffer suitable for use for a frame buffer of the
  97  *      form described by user space. Give userspace a handle by which
  98  *      to reference it.
  99  */
 100 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 101                         struct drm_mode_create_dumb *args)
 102 {
 103         args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
 104         args->size = args->pitch * args->height;
 105         return psb_gem_create(file, dev, args->size, &args->handle, 0,
 106                               PAGE_SIZE);
 107 }
 108
 109 /**
 110  *      psb_gem_fault           -       pagefault handler for GEM objects
 111  *      @vma: the VMA of the GEM object
 112  *      @vmf: fault detail
 113  *
 114  *      Invoked when a fault occurs on an mmap of a GEM managed area. GEM
 115  *      does most of the work for us including the actual map/unmap calls
 116  *      but we need to do the actual page work.
 117  *
 118  *      This code eventually needs to handle faulting objects in and out
 119  *      of the GTT and repacking it when we run out of space. We can put
 120  *      that off for now and for our simple uses
 121  *
 122  *      The VMA was set up by GEM. In doing so it also ensured that the
 123  *      vma->vm_private_data points to the GEM object that is backing this
 124  *      mapping.
 125  */
 126 vm_fault_t psb_gem_fault(struct vm_fault *vmf)
 127 {
 128         struct vm_area_struct *vma = vmf->vma;
 129         struct drm_gem_object *obj;
 130         struct gtt_range *r;
 131         int err;
 132         vm_fault_t ret;
 133         unsigned long pfn;
 134         pgoff_t page_offset;
 135         struct drm_device *dev;
 136         struct drm_psb_private *dev_priv;
 137
 138         obj = vma->vm_private_data;     /* GEM object */
 139         dev = obj->dev;
 140         dev_priv = dev->dev_private;
 141
 142         r = container_of(obj, struct gtt_range, gem);   /* Get the gtt range */
 143
 144         /* Make sure we don't parallel update on a fault, nor move or remove
 145            something from beneath our feet */
 146         mutex_lock(&dev_priv->mmap_mutex);
 147
 148         /* For now the mmap pins the object and it stays pinned. As things
 149            stand that will do us no harm */
 150         if (r->mmapping == 0) {
 151                 err = psb_gtt_pin(r);
 152                 if (err < 0) {
 153                         dev_err(dev->dev, "gma500: pin failed: %d\n", err);
 154                         ret = vmf_error(err);
 155                         goto fail;
 156                 }
 157                 r->mmapping = 1;
 158         }
 159
 160         /* Page relative to the VMA start - we must calculate this ourselves
 161            because vmf->pgoff is the fake GEM offset */
 162         page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 163
 164         /* CPU view of the page, don't go via the GART for CPU writes */
 165         if (r->stolen)
 166                 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 167         else
 168                 pfn = page_to_pfn(r->pages[page_offset]);
 169         ret = vmf_insert_pfn(vma, vmf->address, pfn);
 170 fail:
 171         mutex_unlock(&dev_priv->mmap_mutex);
 172
 173         return ret;
 174 }