200 lines · c
1/*2 * SPDX-License-Identifier: MIT3 *4 * Copyright © 2014-2016 Intel Corporation5 */6 7#include <linux/scatterlist.h>8#include <linux/slab.h>9 10#include "i915_drv.h"11#include "i915_gem.h"12#include "i915_gem_internal.h"13#include "i915_gem_object.h"14#include "i915_scatterlist.h"15#include "i915_utils.h"16 17#define QUIET (__GFP_NORETRY | __GFP_NOWARN)18#define MAYFAIL (__GFP_RETRY_MAYFAIL | __GFP_NOWARN)19 20static void internal_free_pages(struct sg_table *st)21{22 struct scatterlist *sg;23 24 for (sg = st->sgl; sg; sg = __sg_next(sg)) {25 if (sg_page(sg))26 __free_pages(sg_page(sg), get_order(sg->length));27 }28 29 sg_free_table(st);30 kfree(st);31}32 33static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)34{35 struct drm_i915_private *i915 = to_i915(obj->base.dev);36 struct sg_table *st;37 struct scatterlist *sg;38 unsigned int npages; /* restricted by sg_alloc_table */39 int max_order = MAX_PAGE_ORDER;40 unsigned int max_segment;41 gfp_t gfp;42 43 if (overflows_type(obj->base.size >> PAGE_SHIFT, npages))44 return -E2BIG;45 46 npages = obj->base.size >> PAGE_SHIFT;47 max_segment = i915_sg_segment_size(i915->drm.dev) >> PAGE_SHIFT;48 max_order = min(max_order, get_order(max_segment));49 50 gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;51 if (IS_I965GM(i915) || IS_I965G(i915)) {52 /* 965gm cannot relocate objects above 4GiB. */53 gfp &= ~__GFP_HIGHMEM;54 gfp |= __GFP_DMA32;55 }56 57create_st:58 st = kmalloc(sizeof(*st), GFP_KERNEL);59 if (!st)60 return -ENOMEM;61 62 if (sg_alloc_table(st, npages, GFP_KERNEL)) {63 kfree(st);64 return -ENOMEM;65 }66 67 sg = st->sgl;68 st->nents = 0;69 70 do {71 int order = min(fls(npages) - 1, max_order);72 struct page *page;73 74 do {75 page = alloc_pages(gfp | (order ? QUIET : MAYFAIL),76 order);77 if (page)78 break;79 if (!order--)80 goto err;81 82 /* Limit subsequent allocations as well */83 max_order = order;84 } while (1);85 86 sg_set_page(sg, page, PAGE_SIZE << order, 0);87 st->nents++;88 89 npages -= 1 << order;90 if (!npages) {91 sg_mark_end(sg);92 break;93 }94 95 sg = __sg_next(sg);96 } while (1);97 98 if (i915_gem_gtt_prepare_pages(obj, st)) {99 /* Failed to dma-map try again with single page sg segments */100 if (get_order(st->sgl->length)) {101 internal_free_pages(st);102 max_order = 0;103 goto create_st;104 }105 goto err;106 }107 108 __i915_gem_object_set_pages(obj, st);109 110 return 0;111 112err:113 sg_set_page(sg, NULL, 0, 0);114 sg_mark_end(sg);115 internal_free_pages(st);116 117 return -ENOMEM;118}119 120static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,121 struct sg_table *pages)122{123 i915_gem_gtt_finish_pages(obj, pages);124 internal_free_pages(pages);125 126 obj->mm.dirty = false;127 128 __start_cpu_write(obj);129}130 131static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {132 .name = "i915_gem_object_internal",133 .flags = I915_GEM_OBJECT_IS_SHRINKABLE,134 .get_pages = i915_gem_object_get_pages_internal,135 .put_pages = i915_gem_object_put_pages_internal,136};137 138struct drm_i915_gem_object *139__i915_gem_object_create_internal(struct drm_i915_private *i915,140 const struct drm_i915_gem_object_ops *ops,141 phys_addr_t size)142{143 static struct lock_class_key lock_class;144 struct drm_i915_gem_object *obj;145 unsigned int cache_level;146 147 GEM_BUG_ON(!size);148 GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));149 150 if (overflows_type(size, obj->base.size))151 return ERR_PTR(-E2BIG);152 153 obj = i915_gem_object_alloc();154 if (!obj)155 return ERR_PTR(-ENOMEM);156 157 drm_gem_private_object_init(&i915->drm, &obj->base, size);158 i915_gem_object_init(obj, ops, &lock_class, 0);159 obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE;160 161 /*162 * Mark the object as volatile, such that the pages are marked as163 * dontneed whilst they are still pinned. As soon as they are unpinned164 * they are allowed to be reaped by the shrinker, and the caller is165 * expected to repopulate - the contents of this object are only valid166 * whilst active and pinned.167 */168 i915_gem_object_set_volatile(obj);169 170 obj->read_domains = I915_GEM_DOMAIN_CPU;171 obj->write_domain = I915_GEM_DOMAIN_CPU;172 173 cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;174 i915_gem_object_set_cache_coherency(obj, cache_level);175 176 return obj;177}178 179/**180 * i915_gem_object_create_internal: create an object with volatile pages181 * @i915: the i915 device182 * @size: the size in bytes of backing storage to allocate for the object183 *184 * Creates a new object that wraps some internal memory for private use.185 * This object is not backed by swappable storage, and as such its contents186 * are volatile and only valid whilst pinned. If the object is reaped by the187 * shrinker, its pages and data will be discarded. Equally, it is not a full188 * GEM object and so not valid for access from userspace. This makes it useful189 * for hardware interfaces like ringbuffers (which are pinned from the time190 * the request is written to the time the hardware stops accessing it), but191 * not for contexts (which need to be preserved when not active for later192 * reuse). Note that it is not cleared upon allocation.193 */194struct drm_i915_gem_object *195i915_gem_object_create_internal(struct drm_i915_private *i915,196 phys_addr_t size)197{198 return __i915_gem_object_create_internal(i915, &i915_gem_object_internal_ops, size);199}200