LXR linux/drivers/gpu/drm/i915/i915_gem

   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
  34static 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
  47static struct sg_table *
  48i915_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 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
  78create_st:
  79        st = kmalloc(sizeof(*st), GFP_KERNEL);
  80        if (!st)
  81                return ERR_PTR(-ENOMEM);
  82
  83        npages = obj->base.size / PAGE_SIZE;
  84        if (sg_alloc_table(st, npages, GFP_KERNEL)) {
  85                kfree(st);
  86                return ERR_PTR(-ENOMEM);
  87        }
  88
  89        sg = st->sgl;
  90        st->nents = 0;
  91
  92        do {
  93                int order = min(fls(npages) - 1, max_order);
  94                struct page *page;
  95
  96                do {
  97                        page = alloc_pages(gfp | (order ? QUIET : 0), order);
  98                        if (page)
  99                                break;
 100                        if (!order--)
 101                                goto err;
 102
 103                        /* Limit subsequent allocations as well */
 104                        max_order = order;
 105                } while (1);
 106
 107                sg_set_page(sg, page, PAGE_SIZE << order, 0);
 108                st->nents++;
 109
 110                npages -= 1 << order;
 111                if (!npages) {
 112                        sg_mark_end(sg);
 113                        break;
 114                }
 115
 116                sg = __sg_next(sg);
 117        } while (1);
 118
 119        if (i915_gem_gtt_prepare_pages(obj, st)) {
 120                /* Failed to dma-map try again with single page sg segments */
 121                if (get_order(st->sgl->length)) {
 122                        internal_free_pages(st);
 123                        max_order = 0;
 124                        goto create_st;
 125                }
 126                goto err;
 127        }
 128
 129        /* Mark the pages as dontneed whilst they are still pinned. As soon
 130         * as they are unpinned they are allowed to be reaped by the shrinker,
 131         * and the caller is expected to repopulate - the contents of this
 132         * object are only valid whilst active and pinned.
 133         */
 134        obj->mm.madv = I915_MADV_DONTNEED;
 135        return st;
 136
 137err:
 138        sg_set_page(sg, NULL, 0, 0);
 139        sg_mark_end(sg);
 140        internal_free_pages(st);
 141        return ERR_PTR(-ENOMEM);
 142}
 143
 144static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
 145                                               struct sg_table *pages)
 146{
 147        i915_gem_gtt_finish_pages(obj, pages);
 148        internal_free_pages(pages);
 149
 150        obj->mm.dirty = false;
 151        obj->mm.madv = I915_MADV_WILLNEED;
 152}
 153
 154static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
 155        .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
 156                 I915_GEM_OBJECT_IS_SHRINKABLE,
 157        .get_pages = i915_gem_object_get_pages_internal,
 158        .put_pages = i915_gem_object_put_pages_internal,
 159};
 160
 161/**
 162 * Creates a new object that wraps some internal memory for private use.
 163 * This object is not backed by swappable storage, and as such its contents
 164 * are volatile and only valid whilst pinned. If the object is reaped by the
 165 * shrinker, its pages and data will be discarded. Equally, it is not a full
 166 * GEM object and so not valid for access from userspace. This makes it useful
 167 * for hardware interfaces like ringbuffers (which are pinned from the time
 168 * the request is written to the time the hardware stops accessing it), but
 169 * not for contexts (which need to be preserved when not active for later
 170 * reuse). Note that it is not cleared upon allocation.
 171 */
 172struct drm_i915_gem_object *
 173i915_gem_object_create_internal(struct drm_i915_private *i915,
 174                                phys_addr_t size)
 175{
 176        struct drm_i915_gem_object *obj;
 177
 178        GEM_BUG_ON(!size);
 179        GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
 180
 181        if (overflows_type(size, obj->base.size))
 182                return ERR_PTR(-E2BIG);
 183
 184        obj = i915_gem_object_alloc(i915);
 185        if (!obj)
 186                return ERR_PTR(-ENOMEM);
 187
 188        drm_gem_private_object_init(&i915->drm, &obj->base, size);
 189        i915_gem_object_init(obj, &i915_gem_object_internal_ops);
 190
 191        obj->base.read_domains = I915_GEM_DOMAIN_CPU;
 192        obj->base.write_domain = I915_GEM_DOMAIN_CPU;
 193        obj->cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
 194        obj->cache_coherent = i915_gem_object_is_coherent(obj);
 195        obj->cache_dirty = !obj->cache_coherent;
 196
 197        return obj;
 198}
 199