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 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 #undef QUIET 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 npages; /* restricted by sg_alloc_table */ 40 int max_order = MAX_ORDER; 41 unsigned int max_segment; 42 gfp_t gfp; 43 44 if (overflows_type(obj->base.size >> PAGE_SHIFT, npages)) 45 return -E2BIG; 46 47 npages = obj->base.size >> PAGE_SHIFT; 48 max_segment = i915_sg_segment_size(i915->drm.dev) >> PAGE_SHIFT; 49 max_order = min(max_order, get_order(max_segment)); 50 51 gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE; 52 if (IS_I965GM(i915) || IS_I965G(i915)) { 53 /* 965gm cannot relocate objects above 4GiB. */ 54 gfp &= ~__GFP_HIGHMEM; 55 gfp |= __GFP_DMA32; 56 } 57 58 create_st: 59 st = kmalloc(sizeof(*st), GFP_KERNEL); 60 if (!st) 61 return -ENOMEM; 62 63 if (sg_alloc_table(st, npages, GFP_KERNEL)) { 64 kfree(st); 65 return -ENOMEM; 66 } 67 68 sg = st->sgl; 69 st->nents = 0; 70 71 do { 72 int order = min(fls(npages) - 1, max_order); 73 struct vm_page *page; 74 75 do { 76 page = alloc_pages(gfp | (order ? QUIET : MAYFAIL), 77 order); 78 if (page) 79 break; 80 if (!order--) 81 goto err; 82 83 /* Limit subsequent allocations as well */ 84 max_order = order; 85 } while (1); 86 87 sg_set_page(sg, page, PAGE_SIZE << order, 0); 88 st->nents++; 89 90 npages -= 1 << order; 91 if (!npages) { 92 sg_mark_end(sg); 93 break; 94 } 95 96 sg = __sg_next(sg); 97 } while (1); 98 99 if (i915_gem_gtt_prepare_pages(obj, st)) { 100 /* Failed to dma-map try again with single page sg segments */ 101 if (get_order(st->sgl->length)) { 102 internal_free_pages(st); 103 max_order = 0; 104 goto create_st; 105 } 106 goto err; 107 } 108 109 __i915_gem_object_set_pages(obj, st); 110 111 return 0; 112 113 err: 114 sg_set_page(sg, NULL, 0, 0); 115 sg_mark_end(sg); 116 internal_free_pages(st); 117 118 return -ENOMEM; 119 } 120 121 static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj, 122 struct sg_table *pages) 123 { 124 i915_gem_gtt_finish_pages(obj, pages); 125 internal_free_pages(pages); 126 127 obj->mm.dirty = false; 128 129 __start_cpu_write(obj); 130 } 131 132 static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = { 133 .name = "i915_gem_object_internal", 134 .flags = I915_GEM_OBJECT_IS_SHRINKABLE, 135 .get_pages = i915_gem_object_get_pages_internal, 136 .put_pages = i915_gem_object_put_pages_internal, 137 }; 138 139 struct drm_i915_gem_object * 140 __i915_gem_object_create_internal(struct drm_i915_private *i915, 141 const struct drm_i915_gem_object_ops *ops, 142 phys_addr_t size) 143 { 144 static struct lock_class_key lock_class; 145 struct drm_i915_gem_object *obj; 146 unsigned int cache_level; 147 148 GEM_BUG_ON(!size); 149 GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE)); 150 151 if (overflows_type(size, obj->base.size)) 152 return ERR_PTR(-E2BIG); 153 154 obj = i915_gem_object_alloc(); 155 if (!obj) 156 return ERR_PTR(-ENOMEM); 157 158 drm_gem_private_object_init(&i915->drm, &obj->base, size); 159 i915_gem_object_init(obj, ops, &lock_class, 0); 160 obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE; 161 162 /* 163 * Mark the object as volatile, such that the pages are marked as 164 * dontneed whilst they are still pinned. As soon as they are unpinned 165 * they are allowed to be reaped by the shrinker, and the caller is 166 * expected to repopulate - the contents of this object are only valid 167 * whilst active and pinned. 168 */ 169 i915_gem_object_set_volatile(obj); 170 171 obj->read_domains = I915_GEM_DOMAIN_CPU; 172 obj->write_domain = I915_GEM_DOMAIN_CPU; 173 174 cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE; 175 i915_gem_object_set_cache_coherency(obj, cache_level); 176 177 return obj; 178 } 179 180 /** 181 * i915_gem_object_create_internal: create an object with volatile pages 182 * @i915: the i915 device 183 * @size: the size in bytes of backing storage to allocate for the object 184 * 185 * Creates a new object that wraps some internal memory for private use. 186 * This object is not backed by swappable storage, and as such its contents 187 * are volatile and only valid whilst pinned. If the object is reaped by the 188 * shrinker, its pages and data will be discarded. Equally, it is not a full 189 * GEM object and so not valid for access from userspace. This makes it useful 190 * for hardware interfaces like ringbuffers (which are pinned from the time 191 * the request is written to the time the hardware stops accessing it), but 192 * not for contexts (which need to be preserved when not active for later 193 * reuse). Note that it is not cleared upon allocation. 194 */ 195 struct drm_i915_gem_object * 196 i915_gem_object_create_internal(struct drm_i915_private *i915, 197 phys_addr_t size) 198 { 199 return __i915_gem_object_create_internal(i915, &i915_gem_object_internal_ops, size); 200 } 201