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 #define MAYFAIL (__GFP_RETRY_MAYFAIL | __GFP_NOWARN)
  31
  32 /* convert swiotlb segment size into sensible units (pages)! */
  33 #define IO_TLB_SEGPAGES (IO_TLB_SEGSIZE << IO_TLB_SHIFT >> PAGE_SHIFT)
  34
  35 static void internal_free_pages(struct sg_table *st)
  36 {
  37         struct scatterlist *sg;
  38
  39         for (sg = st->sgl; sg; sg = __sg_next(sg)) {
  40                 if (sg_page(sg))
  41                         __free_pages(sg_page(sg), get_order(sg->length));
  42         }
  43
  44         sg_free_table(st);
  45         kfree(st);
  46 }
  47
  48 static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
  49 {
  50         struct drm_i915_private *i915 = to_i915(obj->base.dev);
  51         struct sg_table *st;
  52         struct scatterlist *sg;
  53         unsigned int sg_page_sizes;
  54         unsigned int npages;
  55         int max_order;
  56         gfp_t gfp;
  57
  58         max_order = MAX_ORDER;
  59 #ifdef CONFIG_SWIOTLB
  60         if (swiotlb_nr_tbl()) {
  61                 unsigned int max_segment;
  62
  63                 max_segment = swiotlb_max_segment();
  64                 if (max_segment) {
  65                         max_segment = max_t(unsigned int, max_segment,
  66                                             PAGE_SIZE) >> PAGE_SHIFT;
  67                         max_order = min(max_order, ilog2(max_segment));
  68                 }
  69         }
  70 #endif
  71
  72         gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
  73         if (IS_I965GM(i915) || IS_I965G(i915)) {
  74                 /* 965gm cannot relocate objects above 4GiB. */
  75                 gfp &= ~__GFP_HIGHMEM;
  76                 gfp |= __GFP_DMA32;
  77         }
  78
  79 create_st:
  80         st = kmalloc(sizeof(*st), GFP_KERNEL);
  81         if (!st)
  82                 return -ENOMEM;
  83
  84         npages = obj->base.size / PAGE_SIZE;
  85         if (sg_alloc_table(st, npages, GFP_KERNEL)) {
  86                 kfree(st);
  87                 return -ENOMEM;
  88         }
  89
  90         sg = st->sgl;
  91         st->nents = 0;
  92         sg_page_sizes = 0;
  93
  94         do {
  95                 int order = min(fls(npages) - 1, max_order);
  96                 struct page *page;
  97
  98                 do {
  99                         page = alloc_pages(gfp | (order ? QUIET : MAYFAIL),
 100                                            order);
 101                         if (page)
 102                                 break;
 103                         if (!order--)
 104                                 goto err;
 105
 106                         /* Limit subsequent allocations as well */
 107                         max_order = order;
 108                 } while (1);
 109
 110                 sg_set_page(sg, page, PAGE_SIZE << order, 0);
 111                 sg_page_sizes |= PAGE_SIZE << order;
 112                 st->nents++;
 113
 114                 npages -= 1 << order;
 115                 if (!npages) {
 116                         sg_mark_end(sg);
 117                         break;
 118                 }
 119
 120                 sg = __sg_next(sg);
 121         } while (1);
 122
 123         if (i915_gem_gtt_prepare_pages(obj, st)) {
 124                 /* Failed to dma-map try again with single page sg segments */
 125                 if (get_order(st->sgl->length)) {
 126                         internal_free_pages(st);
 127                         max_order = 0;
 128                         goto create_st;
 129                 }
 130                 goto err;
 131         }
 132
 133         /* Mark the pages as dontneed whilst they are still pinned. As soon
 134          * as they are unpinned they are allowed to be reaped by the shrinker,
 135          * and the caller is expected to repopulate - the contents of this
 136          * object are only valid whilst active and pinned.
 137          */
 138         obj->mm.madv = I915_MADV_DONTNEED;
 139
 140         __i915_gem_object_set_pages(obj, st, sg_page_sizes);
 141
 142         return 0;
 143
 144 err:
 145         sg_set_page(sg, NULL, 0, 0);
 146         sg_mark_end(sg);
 147         internal_free_pages(st);
 148
 149         return -ENOMEM;
 150 }
 151
 152 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
 153                                                struct sg_table *pages)
 154 {
 155         i915_gem_gtt_finish_pages(obj, pages);
 156         internal_free_pages(pages);
 157
 158         obj->mm.dirty = false;
 159         obj->mm.madv = I915_MADV_WILLNEED;
 160 }
 161
 162 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
 163         .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
 164                  I915_GEM_OBJECT_IS_SHRINKABLE,
 165         .get_pages = i915_gem_object_get_pages_internal,
 166         .put_pages = i915_gem_object_put_pages_internal,
 167 };
 168
 169 /**
 170  * i915_gem_object_create_internal: create an object with volatile pages
 171  * @i915: the i915 device
 172  * @size: the size in bytes of backing storage to allocate for the object
 173  *
 174  * Creates a new object that wraps some internal memory for private use.
 175  * This object is not backed by swappable storage, and as such its contents
 176  * are volatile and only valid whilst pinned. If the object is reaped by the
 177  * shrinker, its pages and data will be discarded. Equally, it is not a full
 178  * GEM object and so not valid for access from userspace. This makes it useful
 179  * for hardware interfaces like ringbuffers (which are pinned from the time
 180  * the request is written to the time the hardware stops accessing it), but
 181  * not for contexts (which need to be preserved when not active for later
 182  * reuse). Note that it is not cleared upon allocation.
 183  */
 184 struct drm_i915_gem_object *
 185 i915_gem_object_create_internal(struct drm_i915_private *i915,
 186                                 phys_addr_t size)
 187 {
 188         struct drm_i915_gem_object *obj;
 189         unsigned int cache_level;
 190
 191         GEM_BUG_ON(!size);
 192         GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
 193
 194         if (overflows_type(size, obj->base.size))
 195                 return ERR_PTR(-E2BIG);
 196
 197         obj = i915_gem_object_alloc(i915);
 198         if (!obj)
 199                 return ERR_PTR(-ENOMEM);
 200
 201         drm_gem_private_object_init(&i915->drm, &obj->base, size);
 202         i915_gem_object_init(obj, &i915_gem_object_internal_ops);
 203
 204         obj->read_domains = I915_GEM_DOMAIN_CPU;
 205         obj->write_domain = I915_GEM_DOMAIN_CPU;
 206
 207         cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 208         i915_gem_object_set_cache_coherency(obj, cache_level);
 209
 210         return obj;
 211 }