drivers/gpu/drm/i915/i915_gem_internal.c

   1 /*
   2  * Copyright © 2014-2016 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  */
  24
  25 #include <drm/drmP.h>
  26 #include <drm/i915_drm.h>
  27 #include "i915_drv.h"
  28
  29 #define QUIET (__GFP_NORETRY | __GFP_NOWARN)
  30
  31 /* convert swiotlb segment size into sensible units (pages)! */
  32 #define IO_TLB_SEGPAGES (IO_TLB_SEGSIZE << IO_TLB_SHIFT >> PAGE_SHIFT)
  33
  34 static void internal_free_pages(struct sg_table *st)
  35 {
  36         struct scatterlist *sg;
  37
  38         for (sg = st->sgl; sg; sg = __sg_next(sg))
  39                 __free_pages(sg_page(sg), get_order(sg->length));
  40
  41         sg_free_table(st);
  42         kfree(st);
  43 }
  44
  45 static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
  46 {
  47         struct drm_i915_private *i915 = to_i915(obj->base.dev);
  48         unsigned int npages = obj->base.size / PAGE_SIZE;
  49         struct sg_table *st;
  50         struct scatterlist *sg;
  51         int max_order;
  52         gfp_t gfp;
  53
  54         st = kmalloc(sizeof(*st), GFP_KERNEL);
  55         if (!st)
  56                 return -ENOMEM;
  57
  58         if (sg_alloc_table(st, npages, GFP_KERNEL)) {
  59                 kfree(st);
  60                 return -ENOMEM;
  61         }
  62
  63         sg = st->sgl;
  64         st->nents = 0;
  65
  66         max_order = MAX_ORDER;
  67 #ifdef CONFIG_SWIOTLB
  68         if (swiotlb_nr_tbl()) /* minimum max swiotlb size is IO_TLB_SEGSIZE */
  69                 max_order = min(max_order, ilog2(IO_TLB_SEGPAGES));
  70 #endif
  71
  72         gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
  73         if (IS_CRESTLINE(i915) || IS_BROADWATER(i915)) {
  74                 /* 965gm cannot relocate objects above 4GiB. */
  75                 gfp &= ~__GFP_HIGHMEM;
  76                 gfp |= __GFP_DMA32;
  77         }
  78
  79         do {
  80                 int order = min(fls(npages) - 1, max_order);
  81                 struct page *page;
  82
  83                 do {
  84                         page = alloc_pages(gfp | (order ? QUIET : 0), order);
  85                         if (page)
  86                                 break;
  87                         if (!order--)
  88                                 goto err;
  89
  90                         /* Limit subsequent allocations as well */
  91                         max_order = order;
  92                 } while (1);
  93
  94                 sg_set_page(sg, page, PAGE_SIZE << order, 0);
  95                 st->nents++;
  96
  97                 npages -= 1 << order;
  98                 if (!npages) {
  99                         sg_mark_end(sg);
 100                         break;
 101                 }
 102
 103                 sg = __sg_next(sg);
 104         } while (1);
 105         obj->mm.pages = st;
 106
 107         if (i915_gem_gtt_prepare_object(obj)) {
 108                 obj->mm.pages = NULL;
 109                 goto err;
 110         }
 111
 112         /* Mark the pages as dontneed whilst they are still pinned. As soon
 113          * as they are unpinned they are allowed to be reaped by the shrinker,
 114          * and the caller is expected to repopulate - the contents of this
 115          * object are only valid whilst active and pinned.
 116          */
 117         obj->mm.madv = I915_MADV_DONTNEED;
 118         return 0;
 119
 120 err:
 121         sg_mark_end(sg);
 122         internal_free_pages(st);
 123         return -ENOMEM;
 124 }
 125
 126 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj)
 127 {
 128         i915_gem_gtt_finish_object(obj);
 129         internal_free_pages(obj->mm.pages);
 130
 131         obj->mm.dirty = false;
 132         obj->mm.madv = I915_MADV_WILLNEED;
 133 }
 134
 135 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
 136         .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE,
 137         .get_pages = i915_gem_object_get_pages_internal,
 138         .put_pages = i915_gem_object_put_pages_internal,
 139 };
 140
 141 /**
 142  * Creates a new object that wraps some internal memory for private use.
 143  * This object is not backed by swappable storage, and as such its contents
 144  * are volatile and only valid whilst pinned. If the object is reaped by the
 145  * shrinker, its pages and data will be discarded. Equally, it is not a full
 146  * GEM object and so not valid for access from userspace. This makes it useful
 147  * for hardware interfaces like ringbuffers (which are pinned from the time
 148  * the request is written to the time the hardware stops accessing it), but
 149  * not for contexts (which need to be preserved when not active for later
 150  * reuse). Note that it is not cleared upon allocation.
 151  */
 152 struct drm_i915_gem_object *
 153 i915_gem_object_create_internal(struct drm_i915_private *i915,
 154                                 unsigned int size)
 155 {
 156         struct drm_i915_gem_object *obj;
 157
 158         obj = i915_gem_object_alloc(&i915->drm);
 159         if (!obj)
 160                 return ERR_PTR(-ENOMEM);
 161
 162         drm_gem_private_object_init(&i915->drm, &obj->base, size);
 163         i915_gem_object_init(obj, &i915_gem_object_internal_ops);
 164
 165         obj->base.write_domain = I915_GEM_DOMAIN_CPU;
 166         obj->base.read_domains = I915_GEM_DOMAIN_CPU;
 167         obj->cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 168
 169         return obj;
 170 }