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/i915_drm.h>
  26 #include "i915_drv.h"
  27
  28 #define QUIET (__GFP_NORETRY | __GFP_NOWARN)
  29 #define MAYFAIL (__GFP_RETRY_MAYFAIL | __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                 if (sg_page(sg))
  40                         __free_pages(sg_page(sg), get_order(sg->length));
  41         }
  42
  43         sg_free_table(st);
  44         kfree(st);
  45 }
  46
  47 static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
  48 {
  49         struct drm_i915_private *i915 = to_i915(obj->base.dev);
  50         struct sg_table *st;
  51         struct scatterlist *sg;
  52         unsigned int sg_page_sizes;
  53         unsigned int npages;
  54         int max_order;
  55         gfp_t gfp;
  56
  57         max_order = MAX_ORDER;
  58 #ifdef CONFIG_SWIOTLB
  59         if (swiotlb_nr_tbl()) {
  60                 unsigned int max_segment;
  61
  62                 max_segment = swiotlb_max_segment();
  63                 if (max_segment) {
  64                         max_segment = max_t(unsigned int, max_segment,
  65                                             PAGE_SIZE) >> PAGE_SHIFT;
  66                         max_order = min(max_order, ilog2(max_segment));
  67                 }
  68         }
  69 #endif
  70
  71         gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
  72         if (IS_I965GM(i915) || IS_I965G(i915)) {
  73                 /* 965gm cannot relocate objects above 4GiB. */
  74                 gfp &= ~__GFP_HIGHMEM;
  75                 gfp |= __GFP_DMA32;
  76         }
  77
  78 create_st:
  79         st = kmalloc(sizeof(*st), GFP_KERNEL);
  80         if (!st)
  81                 return -ENOMEM;
  82
  83         npages = obj->base.size / PAGE_SIZE;
  84         if (sg_alloc_table(st, npages, GFP_KERNEL)) {
  85                 kfree(st);
  86                 return -ENOMEM;
  87         }
  88
  89         sg = st->sgl;
  90         st->nents = 0;
  91         sg_page_sizes = 0;
  92
  93         do {
  94                 int order = min(fls(npages) - 1, max_order);
  95                 struct page *page;
  96
  97                 do {
  98                         page = alloc_pages(gfp | (order ? QUIET : MAYFAIL),
  99                                            order);
 100                         if (page)
 101                                 break;
 102                         if (!order--)
 103                                 goto err;
 104
 105                         /* Limit subsequent allocations as well */
 106                         max_order = order;
 107                 } while (1);
 108
 109                 sg_set_page(sg, page, PAGE_SIZE << order, 0);
 110                 sg_page_sizes |= PAGE_SIZE << order;
 111                 st->nents++;
 112
 113                 npages -= 1 << order;
 114                 if (!npages) {
 115                         sg_mark_end(sg);
 116                         break;
 117                 }
 118
 119                 sg = __sg_next(sg);
 120         } while (1);
 121
 122         if (i915_gem_gtt_prepare_pages(obj, st)) {
 123                 /* Failed to dma-map try again with single page sg segments */
 124                 if (get_order(st->sgl->length)) {
 125                         internal_free_pages(st);
 126                         max_order = 0;
 127                         goto create_st;
 128                 }
 129                 goto err;
 130         }
 131
 132         /* Mark the pages as dontneed whilst they are still pinned. As soon
 133          * as they are unpinned they are allowed to be reaped by the shrinker,
 134          * and the caller is expected to repopulate - the contents of this
 135          * object are only valid whilst active and pinned.
 136          */
 137         obj->mm.madv = I915_MADV_DONTNEED;
 138
 139         __i915_gem_object_set_pages(obj, st, sg_page_sizes);
 140
 141         return 0;
 142
 143 err:
 144         sg_set_page(sg, NULL, 0, 0);
 145         sg_mark_end(sg);
 146         internal_free_pages(st);
 147
 148         return -ENOMEM;
 149 }
 150
 151 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
 152                                                struct sg_table *pages)
 153 {
 154         i915_gem_gtt_finish_pages(obj, pages);
 155         internal_free_pages(pages);
 156
 157         obj->mm.dirty = false;
 158         obj->mm.madv = I915_MADV_WILLNEED;
 159 }
 160
 161 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
 162         .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
 163                  I915_GEM_OBJECT_IS_SHRINKABLE,
 164         .get_pages = i915_gem_object_get_pages_internal,
 165         .put_pages = i915_gem_object_put_pages_internal,
 166 };
 167
 168 /**
 169  * i915_gem_object_create_internal: create an object with volatile pages
 170  * @i915: the i915 device
 171  * @size: the size in bytes of backing storage to allocate for the object
 172  *
 173  * Creates a new object that wraps some internal memory for private use.
 174  * This object is not backed by swappable storage, and as such its contents
 175  * are volatile and only valid whilst pinned. If the object is reaped by the
 176  * shrinker, its pages and data will be discarded. Equally, it is not a full
 177  * GEM object and so not valid for access from userspace. This makes it useful
 178  * for hardware interfaces like ringbuffers (which are pinned from the time
 179  * the request is written to the time the hardware stops accessing it), but
 180  * not for contexts (which need to be preserved when not active for later
 181  * reuse). Note that it is not cleared upon allocation.
 182  */
 183 struct drm_i915_gem_object *
 184 i915_gem_object_create_internal(struct drm_i915_private *i915,
 185                                 phys_addr_t size)
 186 {
 187         struct drm_i915_gem_object *obj;
 188         unsigned int cache_level;
 189
 190         GEM_BUG_ON(!size);
 191         GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
 192
 193         if (overflows_type(size, obj->base.size))
 194                 return ERR_PTR(-E2BIG);
 195
 196         obj = i915_gem_object_alloc();
 197         if (!obj)
 198                 return ERR_PTR(-ENOMEM);
 199
 200         drm_gem_private_object_init(&i915->drm, &obj->base, size);
 201         i915_gem_object_init(obj, &i915_gem_object_internal_ops);
 202
 203         obj->read_domains = I915_GEM_DOMAIN_CPU;
 204         obj->write_domain = I915_GEM_DOMAIN_CPU;
 205
 206         cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 207         i915_gem_object_set_cache_coherency(obj, cache_level);
 208
 209         return obj;
 210 }