1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2014-2016 Intel Corporation 5 */ 6 7 #include <linux/scatterlist.h> 8 #include <linux/slab.h> 9 #include <linux/swiotlb.h> 10 11 #include "i915_drv.h" 12 #include "i915_gem.h" 13 #include "i915_gem_internal.h" 14 #include "i915_gem_object.h" 15 #include "i915_scatterlist.h" 16 #include "i915_utils.h" 17 18 #define QUIET (__GFP_NORETRY | __GFP_NOWARN) 19 #define MAYFAIL (__GFP_RETRY_MAYFAIL | __GFP_NOWARN) 20 21 static void internal_free_pages(struct sg_table *st) 22 { 23 struct scatterlist *sg; 24 25 for (sg = st->sgl; sg; sg = __sg_next(sg)) { 26 if (sg_page(sg)) 27 __free_pages(sg_page(sg), get_order(sg->length)); 28 } 29 30 sg_free_table(st); 31 kfree(st); 32 } 33 34 static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj) 35 { 36 struct drm_i915_private *i915 = to_i915(obj->base.dev); 37 struct sg_table *st; 38 struct scatterlist *sg; 39 unsigned int sg_page_sizes; 40 unsigned int npages; 41 int max_order; 42 gfp_t gfp; 43 44 max_order = MAX_ORDER; 45 #ifdef CONFIG_SWIOTLB 46 if (is_swiotlb_active(obj->base.dev->dev)) { 47 unsigned int max_segment; 48 49 max_segment = swiotlb_max_segment(); 50 if (max_segment) { 51 max_segment = max_t(unsigned int, max_segment, 52 PAGE_SIZE) >> PAGE_SHIFT; 53 max_order = min(max_order, ilog2(max_segment)); 54 } 55 } 56 #endif 57 58 gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE; 59 if (IS_I965GM(i915) || IS_I965G(i915)) { 60 /* 965gm cannot relocate objects above 4GiB. */ 61 gfp &= ~__GFP_HIGHMEM; 62 gfp |= __GFP_DMA32; 63 } 64 65 create_st: 66 st = kmalloc(sizeof(*st), GFP_KERNEL); 67 if (!st) 68 return -ENOMEM; 69 70 npages = obj->base.size / PAGE_SIZE; 71 if (sg_alloc_table(st, npages, GFP_KERNEL)) { 72 kfree(st); 73 return -ENOMEM; 74 } 75 76 sg = st->sgl; 77 st->nents = 0; 78 sg_page_sizes = 0; 79 80 do { 81 int order = min(fls(npages) - 1, max_order); 82 struct page *page; 83 84 do { 85 page = alloc_pages(gfp | (order ? QUIET : MAYFAIL), 86 order); 87 if (page) 88 break; 89 if (!order--) 90 goto err; 91 92 /* Limit subsequent allocations as well */ 93 max_order = order; 94 } while (1); 95 96 sg_set_page(sg, page, PAGE_SIZE << order, 0); 97 sg_page_sizes |= PAGE_SIZE << order; 98 st->nents++; 99 100 npages -= 1 << order; 101 if (!npages) { 102 sg_mark_end(sg); 103 break; 104 } 105 106 sg = __sg_next(sg); 107 } while (1); 108 109 if (i915_gem_gtt_prepare_pages(obj, st)) { 110 /* Failed to dma-map try again with single page sg segments */ 111 if (get_order(st->sgl->length)) { 112 internal_free_pages(st); 113 max_order = 0; 114 goto create_st; 115 } 116 goto err; 117 } 118 119 __i915_gem_object_set_pages(obj, st, sg_page_sizes); 120 121 return 0; 122 123 err: 124 sg_set_page(sg, NULL, 0, 0); 125 sg_mark_end(sg); 126 internal_free_pages(st); 127 128 return -ENOMEM; 129 } 130 131 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj, 132 struct sg_table *pages) 133 { 134 i915_gem_gtt_finish_pages(obj, pages); 135 internal_free_pages(pages); 136 137 obj->mm.dirty = false; 138 139 __start_cpu_write(obj); 140 } 141 142 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = { 143 .name = "i915_gem_object_internal", 144 .flags = I915_GEM_OBJECT_IS_SHRINKABLE, 145 .get_pages = i915_gem_object_get_pages_internal, 146 .put_pages = i915_gem_object_put_pages_internal, 147 }; 148 149 struct drm_i915_gem_object * 150 __i915_gem_object_create_internal(struct drm_i915_private *i915, 151 const struct drm_i915_gem_object_ops *ops, 152 phys_addr_t size) 153 { 154 static struct lock_class_key lock_class; 155 struct drm_i915_gem_object *obj; 156 unsigned int cache_level; 157 158 GEM_BUG_ON(!size); 159 GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE)); 160 161 if (overflows_type(size, obj->base.size)) 162 return ERR_PTR(-E2BIG); 163 164 obj = i915_gem_object_alloc(); 165 if (!obj) 166 return ERR_PTR(-ENOMEM); 167 168 drm_gem_private_object_init(&i915->drm, &obj->base, size); 169 i915_gem_object_init(obj, ops, &lock_class, 0); 170 obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE; 171 172 /* 173 * Mark the object as volatile, such that the pages are marked as 174 * dontneed whilst they are still pinned. As soon as they are unpinned 175 * they are allowed to be reaped by the shrinker, and the caller is 176 * expected to repopulate - the contents of this object are only valid 177 * whilst active and pinned. 178 */ 179 i915_gem_object_set_volatile(obj); 180 181 obj->read_domains = I915_GEM_DOMAIN_CPU; 182 obj->write_domain = I915_GEM_DOMAIN_CPU; 183 184 cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE; 185 i915_gem_object_set_cache_coherency(obj, cache_level); 186 187 return obj; 188 } 189 190 /** 191 * i915_gem_object_create_internal: create an object with volatile pages 192 * @i915: the i915 device 193 * @size: the size in bytes of backing storage to allocate for the object 194 * 195 * Creates a new object that wraps some internal memory for private use. 196 * This object is not backed by swappable storage, and as such its contents 197 * are volatile and only valid whilst pinned. If the object is reaped by the 198 * shrinker, its pages and data will be discarded. Equally, it is not a full 199 * GEM object and so not valid for access from userspace. This makes it useful 200 * for hardware interfaces like ringbuffers (which are pinned from the time 201 * the request is written to the time the hardware stops accessing it), but 202 * not for contexts (which need to be preserved when not active for later 203 * reuse). Note that it is not cleared upon allocation. 204 */ 205 struct drm_i915_gem_object * 206 i915_gem_object_create_internal(struct drm_i915_private *i915, 207 phys_addr_t size) 208 { 209 return __i915_gem_object_create_internal(i915, &i915_gem_object_internal_ops, size); 210 } 211