Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright © 2012-2014 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 | |
Maarten Lankhorst | b588c92 | 2015-05-13 09:56:00 +0200 | [diff] [blame] | 25 | #include <drm/drmP.h> |
| 26 | #include <drm/i915_drm.h> |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 27 | #include "i915_drv.h" |
| 28 | #include "i915_trace.h" |
| 29 | #include "intel_drv.h" |
| 30 | #include <linux/mmu_context.h> |
| 31 | #include <linux/mmu_notifier.h> |
| 32 | #include <linux/mempolicy.h> |
| 33 | #include <linux/swap.h> |
| 34 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 35 | struct i915_mm_struct { |
| 36 | struct mm_struct *mm; |
| 37 | struct drm_device *dev; |
| 38 | struct i915_mmu_notifier *mn; |
| 39 | struct hlist_node node; |
| 40 | struct kref kref; |
| 41 | struct work_struct work; |
| 42 | }; |
| 43 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 44 | #if defined(CONFIG_MMU_NOTIFIER) |
| 45 | #include <linux/interval_tree.h> |
| 46 | |
| 47 | struct i915_mmu_notifier { |
| 48 | spinlock_t lock; |
| 49 | struct hlist_node node; |
| 50 | struct mmu_notifier mn; |
| 51 | struct rb_root objects; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 52 | }; |
| 53 | |
| 54 | struct i915_mmu_object { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 55 | struct i915_mmu_notifier *mn; |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 56 | struct drm_i915_gem_object *obj; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 57 | struct interval_tree_node it; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 58 | struct list_head link; |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 59 | struct work_struct work; |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 60 | bool attached; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 61 | }; |
| 62 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 63 | static void cancel_userptr(struct work_struct *work) |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 64 | { |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 65 | struct i915_mmu_object *mo = container_of(work, typeof(*mo), work); |
| 66 | struct drm_i915_gem_object *obj = mo->obj; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 67 | struct drm_device *dev = obj->base.dev; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 68 | |
| 69 | mutex_lock(&dev->struct_mutex); |
| 70 | /* Cancel any active worker and force us to re-evaluate gup */ |
| 71 | obj->userptr.work = NULL; |
| 72 | |
| 73 | if (obj->pages != NULL) { |
| 74 | struct drm_i915_private *dev_priv = to_i915(dev); |
| 75 | struct i915_vma *vma, *tmp; |
| 76 | bool was_interruptible; |
| 77 | |
| 78 | was_interruptible = dev_priv->mm.interruptible; |
| 79 | dev_priv->mm.interruptible = false; |
| 80 | |
Chris Wilson | 1c7f4bc | 2016-02-26 11:03:19 +0000 | [diff] [blame] | 81 | list_for_each_entry_safe(vma, tmp, &obj->vma_list, obj_link) { |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 82 | int ret = i915_vma_unbind(vma); |
| 83 | WARN_ON(ret && ret != -EIO); |
| 84 | } |
| 85 | WARN_ON(i915_gem_object_put_pages(obj)); |
| 86 | |
| 87 | dev_priv->mm.interruptible = was_interruptible; |
| 88 | } |
| 89 | |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 90 | drm_gem_object_unreference(&obj->base); |
| 91 | mutex_unlock(&dev->struct_mutex); |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 92 | } |
| 93 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 94 | static void add_object(struct i915_mmu_object *mo) |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 95 | { |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 96 | if (mo->attached) |
| 97 | return; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 98 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 99 | interval_tree_insert(&mo->it, &mo->mn->objects); |
| 100 | mo->attached = true; |
| 101 | } |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 102 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 103 | static void del_object(struct i915_mmu_object *mo) |
| 104 | { |
| 105 | if (!mo->attached) |
| 106 | return; |
| 107 | |
| 108 | interval_tree_remove(&mo->it, &mo->mn->objects); |
| 109 | mo->attached = false; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 110 | } |
| 111 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 112 | static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, |
| 113 | struct mm_struct *mm, |
| 114 | unsigned long start, |
| 115 | unsigned long end) |
| 116 | { |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 117 | struct i915_mmu_notifier *mn = |
| 118 | container_of(_mn, struct i915_mmu_notifier, mn); |
| 119 | struct i915_mmu_object *mo; |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 120 | struct interval_tree_node *it; |
| 121 | LIST_HEAD(cancelled); |
| 122 | |
| 123 | if (RB_EMPTY_ROOT(&mn->objects)) |
| 124 | return; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 125 | |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 126 | /* interval ranges are inclusive, but invalidate range is exclusive */ |
| 127 | end--; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 128 | |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 129 | spin_lock(&mn->lock); |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 130 | it = interval_tree_iter_first(&mn->objects, start, end); |
| 131 | while (it) { |
| 132 | /* The mmu_object is released late when destroying the |
| 133 | * GEM object so it is entirely possible to gain a |
| 134 | * reference on an object in the process of being freed |
| 135 | * since our serialisation is via the spinlock and not |
| 136 | * the struct_mutex - and consequently use it after it |
| 137 | * is freed and then double free it. To prevent that |
| 138 | * use-after-free we only acquire a reference on the |
| 139 | * object if it is not in the process of being destroyed. |
| 140 | */ |
| 141 | mo = container_of(it, struct i915_mmu_object, it); |
| 142 | if (kref_get_unless_zero(&mo->obj->base.refcount)) |
| 143 | schedule_work(&mo->work); |
Michał Winiarski | 460822b | 2015-02-03 15:48:17 +0100 | [diff] [blame] | 144 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 145 | list_add(&mo->link, &cancelled); |
| 146 | it = interval_tree_iter_next(it, start, end); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 147 | } |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 148 | list_for_each_entry(mo, &cancelled, link) |
| 149 | del_object(mo); |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 150 | spin_unlock(&mn->lock); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | static const struct mmu_notifier_ops i915_gem_userptr_notifier = { |
| 154 | .invalidate_range_start = i915_gem_userptr_mn_invalidate_range_start, |
| 155 | }; |
| 156 | |
| 157 | static struct i915_mmu_notifier * |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 158 | i915_mmu_notifier_create(struct mm_struct *mm) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 159 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 160 | struct i915_mmu_notifier *mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 161 | int ret; |
| 162 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 163 | mn = kmalloc(sizeof(*mn), GFP_KERNEL); |
| 164 | if (mn == NULL) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 165 | return ERR_PTR(-ENOMEM); |
| 166 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 167 | spin_lock_init(&mn->lock); |
| 168 | mn->mn.ops = &i915_gem_userptr_notifier; |
| 169 | mn->objects = RB_ROOT; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 170 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 171 | /* Protected by mmap_sem (write-lock) */ |
| 172 | ret = __mmu_notifier_register(&mn->mn, mm); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 173 | if (ret) { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 174 | kfree(mn); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 175 | return ERR_PTR(ret); |
| 176 | } |
| 177 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 178 | return mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 179 | } |
| 180 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 181 | static void |
| 182 | i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) |
| 183 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 184 | struct i915_mmu_object *mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 185 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 186 | mo = obj->userptr.mmu_object; |
| 187 | if (mo == NULL) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 188 | return; |
| 189 | |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 190 | spin_lock(&mo->mn->lock); |
| 191 | del_object(mo); |
| 192 | spin_unlock(&mo->mn->lock); |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 193 | kfree(mo); |
| 194 | |
| 195 | obj->userptr.mmu_object = NULL; |
| 196 | } |
| 197 | |
| 198 | static struct i915_mmu_notifier * |
| 199 | i915_mmu_notifier_find(struct i915_mm_struct *mm) |
| 200 | { |
Chris Wilson | e968136 | 2014-09-26 10:31:02 +0100 | [diff] [blame] | 201 | struct i915_mmu_notifier *mn = mm->mn; |
| 202 | |
| 203 | mn = mm->mn; |
| 204 | if (mn) |
| 205 | return mn; |
| 206 | |
| 207 | down_write(&mm->mm->mmap_sem); |
| 208 | mutex_lock(&to_i915(mm->dev)->mm_lock); |
| 209 | if ((mn = mm->mn) == NULL) { |
| 210 | mn = i915_mmu_notifier_create(mm->mm); |
| 211 | if (!IS_ERR(mn)) |
| 212 | mm->mn = mn; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 213 | } |
Chris Wilson | e968136 | 2014-09-26 10:31:02 +0100 | [diff] [blame] | 214 | mutex_unlock(&to_i915(mm->dev)->mm_lock); |
| 215 | up_write(&mm->mm->mmap_sem); |
| 216 | |
| 217 | return mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | static int |
| 221 | i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, |
| 222 | unsigned flags) |
| 223 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 224 | struct i915_mmu_notifier *mn; |
| 225 | struct i915_mmu_object *mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 226 | |
| 227 | if (flags & I915_USERPTR_UNSYNCHRONIZED) |
| 228 | return capable(CAP_SYS_ADMIN) ? 0 : -EPERM; |
| 229 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 230 | if (WARN_ON(obj->userptr.mm == NULL)) |
| 231 | return -EINVAL; |
| 232 | |
| 233 | mn = i915_mmu_notifier_find(obj->userptr.mm); |
| 234 | if (IS_ERR(mn)) |
| 235 | return PTR_ERR(mn); |
| 236 | |
| 237 | mo = kzalloc(sizeof(*mo), GFP_KERNEL); |
| 238 | if (mo == NULL) |
| 239 | return -ENOMEM; |
| 240 | |
| 241 | mo->mn = mn; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 242 | mo->obj = obj; |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 243 | mo->it.start = obj->userptr.ptr; |
| 244 | mo->it.last = obj->userptr.ptr + obj->base.size - 1; |
| 245 | INIT_WORK(&mo->work, cancel_userptr); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 246 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 247 | obj->userptr.mmu_object = mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 248 | return 0; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 249 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 250 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 251 | static void |
| 252 | i915_mmu_notifier_free(struct i915_mmu_notifier *mn, |
| 253 | struct mm_struct *mm) |
| 254 | { |
| 255 | if (mn == NULL) |
| 256 | return; |
| 257 | |
| 258 | mmu_notifier_unregister(&mn->mn, mm); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 259 | kfree(mn); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | #else |
| 263 | |
| 264 | static void |
| 265 | i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) |
| 266 | { |
| 267 | } |
| 268 | |
| 269 | static int |
| 270 | i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, |
| 271 | unsigned flags) |
| 272 | { |
| 273 | if ((flags & I915_USERPTR_UNSYNCHRONIZED) == 0) |
| 274 | return -ENODEV; |
| 275 | |
| 276 | if (!capable(CAP_SYS_ADMIN)) |
| 277 | return -EPERM; |
| 278 | |
| 279 | return 0; |
| 280 | } |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 281 | |
| 282 | static void |
| 283 | i915_mmu_notifier_free(struct i915_mmu_notifier *mn, |
| 284 | struct mm_struct *mm) |
| 285 | { |
| 286 | } |
| 287 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 288 | #endif |
| 289 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 290 | static struct i915_mm_struct * |
| 291 | __i915_mm_struct_find(struct drm_i915_private *dev_priv, struct mm_struct *real) |
| 292 | { |
| 293 | struct i915_mm_struct *mm; |
| 294 | |
| 295 | /* Protected by dev_priv->mm_lock */ |
| 296 | hash_for_each_possible(dev_priv->mm_structs, mm, node, (unsigned long)real) |
| 297 | if (mm->mm == real) |
| 298 | return mm; |
| 299 | |
| 300 | return NULL; |
| 301 | } |
| 302 | |
| 303 | static int |
| 304 | i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj) |
| 305 | { |
| 306 | struct drm_i915_private *dev_priv = to_i915(obj->base.dev); |
| 307 | struct i915_mm_struct *mm; |
| 308 | int ret = 0; |
| 309 | |
| 310 | /* During release of the GEM object we hold the struct_mutex. This |
| 311 | * precludes us from calling mmput() at that time as that may be |
| 312 | * the last reference and so call exit_mmap(). exit_mmap() will |
| 313 | * attempt to reap the vma, and if we were holding a GTT mmap |
| 314 | * would then call drm_gem_vm_close() and attempt to reacquire |
| 315 | * the struct mutex. So in order to avoid that recursion, we have |
| 316 | * to defer releasing the mm reference until after we drop the |
| 317 | * struct_mutex, i.e. we need to schedule a worker to do the clean |
| 318 | * up. |
| 319 | */ |
| 320 | mutex_lock(&dev_priv->mm_lock); |
| 321 | mm = __i915_mm_struct_find(dev_priv, current->mm); |
| 322 | if (mm == NULL) { |
| 323 | mm = kmalloc(sizeof(*mm), GFP_KERNEL); |
| 324 | if (mm == NULL) { |
| 325 | ret = -ENOMEM; |
| 326 | goto out; |
| 327 | } |
| 328 | |
| 329 | kref_init(&mm->kref); |
| 330 | mm->dev = obj->base.dev; |
| 331 | |
| 332 | mm->mm = current->mm; |
| 333 | atomic_inc(¤t->mm->mm_count); |
| 334 | |
| 335 | mm->mn = NULL; |
| 336 | |
| 337 | /* Protected by dev_priv->mm_lock */ |
| 338 | hash_add(dev_priv->mm_structs, |
| 339 | &mm->node, (unsigned long)mm->mm); |
| 340 | } else |
| 341 | kref_get(&mm->kref); |
| 342 | |
| 343 | obj->userptr.mm = mm; |
| 344 | out: |
| 345 | mutex_unlock(&dev_priv->mm_lock); |
| 346 | return ret; |
| 347 | } |
| 348 | |
| 349 | static void |
| 350 | __i915_mm_struct_free__worker(struct work_struct *work) |
| 351 | { |
| 352 | struct i915_mm_struct *mm = container_of(work, typeof(*mm), work); |
| 353 | i915_mmu_notifier_free(mm->mn, mm->mm); |
| 354 | mmdrop(mm->mm); |
| 355 | kfree(mm); |
| 356 | } |
| 357 | |
| 358 | static void |
| 359 | __i915_mm_struct_free(struct kref *kref) |
| 360 | { |
| 361 | struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref); |
| 362 | |
| 363 | /* Protected by dev_priv->mm_lock */ |
| 364 | hash_del(&mm->node); |
| 365 | mutex_unlock(&to_i915(mm->dev)->mm_lock); |
| 366 | |
| 367 | INIT_WORK(&mm->work, __i915_mm_struct_free__worker); |
| 368 | schedule_work(&mm->work); |
| 369 | } |
| 370 | |
| 371 | static void |
| 372 | i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj) |
| 373 | { |
| 374 | if (obj->userptr.mm == NULL) |
| 375 | return; |
| 376 | |
| 377 | kref_put_mutex(&obj->userptr.mm->kref, |
| 378 | __i915_mm_struct_free, |
| 379 | &to_i915(obj->base.dev)->mm_lock); |
| 380 | obj->userptr.mm = NULL; |
| 381 | } |
| 382 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 383 | struct get_pages_work { |
| 384 | struct work_struct work; |
| 385 | struct drm_i915_gem_object *obj; |
| 386 | struct task_struct *task; |
| 387 | }; |
| 388 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 389 | #if IS_ENABLED(CONFIG_SWIOTLB) |
| 390 | #define swiotlb_active() swiotlb_nr_tbl() |
| 391 | #else |
| 392 | #define swiotlb_active() 0 |
| 393 | #endif |
| 394 | |
| 395 | static int |
| 396 | st_set_pages(struct sg_table **st, struct page **pvec, int num_pages) |
| 397 | { |
| 398 | struct scatterlist *sg; |
| 399 | int ret, n; |
| 400 | |
| 401 | *st = kmalloc(sizeof(**st), GFP_KERNEL); |
| 402 | if (*st == NULL) |
| 403 | return -ENOMEM; |
| 404 | |
| 405 | if (swiotlb_active()) { |
| 406 | ret = sg_alloc_table(*st, num_pages, GFP_KERNEL); |
| 407 | if (ret) |
| 408 | goto err; |
| 409 | |
| 410 | for_each_sg((*st)->sgl, sg, num_pages, n) |
| 411 | sg_set_page(sg, pvec[n], PAGE_SIZE, 0); |
| 412 | } else { |
| 413 | ret = sg_alloc_table_from_pages(*st, pvec, num_pages, |
| 414 | 0, num_pages << PAGE_SHIFT, |
| 415 | GFP_KERNEL); |
| 416 | if (ret) |
| 417 | goto err; |
| 418 | } |
| 419 | |
| 420 | return 0; |
| 421 | |
| 422 | err: |
| 423 | kfree(*st); |
| 424 | *st = NULL; |
| 425 | return ret; |
| 426 | } |
| 427 | |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 428 | static int |
| 429 | __i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj, |
| 430 | struct page **pvec, int num_pages) |
| 431 | { |
| 432 | int ret; |
| 433 | |
| 434 | ret = st_set_pages(&obj->pages, pvec, num_pages); |
| 435 | if (ret) |
| 436 | return ret; |
| 437 | |
| 438 | ret = i915_gem_gtt_prepare_object(obj); |
| 439 | if (ret) { |
| 440 | sg_free_table(obj->pages); |
| 441 | kfree(obj->pages); |
| 442 | obj->pages = NULL; |
| 443 | } |
| 444 | |
| 445 | return ret; |
| 446 | } |
| 447 | |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 448 | static int |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 449 | __i915_gem_userptr_set_active(struct drm_i915_gem_object *obj, |
| 450 | bool value) |
| 451 | { |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 452 | int ret = 0; |
| 453 | |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 454 | /* During mm_invalidate_range we need to cancel any userptr that |
| 455 | * overlaps the range being invalidated. Doing so requires the |
| 456 | * struct_mutex, and that risks recursion. In order to cause |
| 457 | * recursion, the user must alias the userptr address space with |
| 458 | * a GTT mmapping (possible with a MAP_FIXED) - then when we have |
| 459 | * to invalidate that mmaping, mm_invalidate_range is called with |
| 460 | * the userptr address *and* the struct_mutex held. To prevent that |
| 461 | * we set a flag under the i915_mmu_notifier spinlock to indicate |
| 462 | * whether this object is valid. |
| 463 | */ |
| 464 | #if defined(CONFIG_MMU_NOTIFIER) |
| 465 | if (obj->userptr.mmu_object == NULL) |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 466 | return 0; |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 467 | |
| 468 | spin_lock(&obj->userptr.mmu_object->mn->lock); |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 469 | /* In order to serialise get_pages with an outstanding |
| 470 | * cancel_userptr, we must drop the struct_mutex and try again. |
| 471 | */ |
Chris Wilson | 768e159 | 2016-01-21 17:32:43 +0000 | [diff] [blame] | 472 | if (!value) |
| 473 | del_object(obj->userptr.mmu_object); |
| 474 | else if (!work_pending(&obj->userptr.mmu_object->work)) |
| 475 | add_object(obj->userptr.mmu_object); |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 476 | else |
| 477 | ret = -EAGAIN; |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 478 | spin_unlock(&obj->userptr.mmu_object->mn->lock); |
| 479 | #endif |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 480 | |
| 481 | return ret; |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 482 | } |
| 483 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 484 | static void |
| 485 | __i915_gem_userptr_get_pages_worker(struct work_struct *_work) |
| 486 | { |
| 487 | struct get_pages_work *work = container_of(_work, typeof(*work), work); |
| 488 | struct drm_i915_gem_object *obj = work->obj; |
| 489 | struct drm_device *dev = obj->base.dev; |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 490 | const int npages = obj->base.size >> PAGE_SHIFT; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 491 | struct page **pvec; |
| 492 | int pinned, ret; |
| 493 | |
| 494 | ret = -ENOMEM; |
| 495 | pinned = 0; |
| 496 | |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 497 | pvec = kmalloc(npages*sizeof(struct page *), |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 498 | GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY); |
| 499 | if (pvec == NULL) |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 500 | pvec = drm_malloc_ab(npages, sizeof(struct page *)); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 501 | if (pvec != NULL) { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 502 | struct mm_struct *mm = obj->userptr.mm->mm; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 503 | |
| 504 | down_read(&mm->mmap_sem); |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 505 | while (pinned < npages) { |
Dave Hansen | 1e98779 | 2016-02-12 13:01:54 -0800 | [diff] [blame] | 506 | ret = get_user_pages_remote(work->task, mm, |
| 507 | obj->userptr.ptr + pinned * PAGE_SIZE, |
| 508 | npages - pinned, |
| 509 | !obj->userptr.read_only, 0, |
| 510 | pvec + pinned, NULL); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 511 | if (ret < 0) |
| 512 | break; |
| 513 | |
| 514 | pinned += ret; |
| 515 | } |
| 516 | up_read(&mm->mmap_sem); |
| 517 | } |
| 518 | |
| 519 | mutex_lock(&dev->struct_mutex); |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 520 | if (obj->userptr.work == &work->work) { |
| 521 | if (pinned == npages) { |
| 522 | ret = __i915_gem_userptr_set_pages(obj, pvec, npages); |
| 523 | if (ret == 0) { |
| 524 | list_add_tail(&obj->global_list, |
| 525 | &to_i915(dev)->mm.unbound_list); |
| 526 | obj->get_page.sg = obj->pages->sgl; |
| 527 | obj->get_page.last = 0; |
| 528 | pinned = 0; |
| 529 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 530 | } |
Chris Wilson | 68d6c84 | 2015-10-01 12:34:45 +0100 | [diff] [blame] | 531 | obj->userptr.work = ERR_PTR(ret); |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 532 | if (ret) |
| 533 | __i915_gem_userptr_set_active(obj, false); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 534 | } |
| 535 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 536 | obj->userptr.workers--; |
| 537 | drm_gem_object_unreference(&obj->base); |
| 538 | mutex_unlock(&dev->struct_mutex); |
| 539 | |
| 540 | release_pages(pvec, pinned, 0); |
| 541 | drm_free_large(pvec); |
| 542 | |
| 543 | put_task_struct(work->task); |
| 544 | kfree(work); |
| 545 | } |
| 546 | |
| 547 | static int |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 548 | __i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj, |
| 549 | bool *active) |
| 550 | { |
| 551 | struct get_pages_work *work; |
| 552 | |
| 553 | /* Spawn a worker so that we can acquire the |
| 554 | * user pages without holding our mutex. Access |
| 555 | * to the user pages requires mmap_sem, and we have |
| 556 | * a strict lock ordering of mmap_sem, struct_mutex - |
| 557 | * we already hold struct_mutex here and so cannot |
| 558 | * call gup without encountering a lock inversion. |
| 559 | * |
| 560 | * Userspace will keep on repeating the operation |
| 561 | * (thanks to EAGAIN) until either we hit the fast |
| 562 | * path or the worker completes. If the worker is |
| 563 | * cancelled or superseded, the task is still run |
| 564 | * but the results ignored. (This leads to |
| 565 | * complications that we may have a stray object |
| 566 | * refcount that we need to be wary of when |
| 567 | * checking for existing objects during creation.) |
| 568 | * If the worker encounters an error, it reports |
| 569 | * that error back to this function through |
| 570 | * obj->userptr.work = ERR_PTR. |
| 571 | */ |
| 572 | if (obj->userptr.workers >= I915_GEM_USERPTR_MAX_WORKERS) |
| 573 | return -EAGAIN; |
| 574 | |
| 575 | work = kmalloc(sizeof(*work), GFP_KERNEL); |
| 576 | if (work == NULL) |
| 577 | return -ENOMEM; |
| 578 | |
| 579 | obj->userptr.work = &work->work; |
| 580 | obj->userptr.workers++; |
| 581 | |
| 582 | work->obj = obj; |
| 583 | drm_gem_object_reference(&obj->base); |
| 584 | |
| 585 | work->task = current; |
| 586 | get_task_struct(work->task); |
| 587 | |
| 588 | INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker); |
| 589 | schedule_work(&work->work); |
| 590 | |
| 591 | *active = true; |
| 592 | return -EAGAIN; |
| 593 | } |
| 594 | |
| 595 | static int |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 596 | i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) |
| 597 | { |
| 598 | const int num_pages = obj->base.size >> PAGE_SHIFT; |
| 599 | struct page **pvec; |
| 600 | int pinned, ret; |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 601 | bool active; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 602 | |
| 603 | /* If userspace should engineer that these pages are replaced in |
| 604 | * the vma between us binding this page into the GTT and completion |
| 605 | * of rendering... Their loss. If they change the mapping of their |
| 606 | * pages they need to create a new bo to point to the new vma. |
| 607 | * |
| 608 | * However, that still leaves open the possibility of the vma |
| 609 | * being copied upon fork. Which falls under the same userspace |
| 610 | * synchronisation issue as a regular bo, except that this time |
| 611 | * the process may not be expecting that a particular piece of |
| 612 | * memory is tied to the GPU. |
| 613 | * |
| 614 | * Fortunately, we can hook into the mmu_notifier in order to |
| 615 | * discard the page references prior to anything nasty happening |
| 616 | * to the vma (discard or cloning) which should prevent the more |
| 617 | * egregious cases from causing harm. |
| 618 | */ |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 619 | if (IS_ERR(obj->userptr.work)) { |
| 620 | /* active flag will have been dropped already by the worker */ |
| 621 | ret = PTR_ERR(obj->userptr.work); |
| 622 | obj->userptr.work = NULL; |
| 623 | return ret; |
| 624 | } |
| 625 | if (obj->userptr.work) |
| 626 | /* active flag should still be held for the pending work */ |
| 627 | return -EAGAIN; |
| 628 | |
| 629 | /* Let the mmu-notifier know that we have begun and need cancellation */ |
Chris Wilson | 380996a | 2015-10-01 12:34:47 +0100 | [diff] [blame] | 630 | ret = __i915_gem_userptr_set_active(obj, true); |
| 631 | if (ret) |
| 632 | return ret; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 633 | |
| 634 | pvec = NULL; |
| 635 | pinned = 0; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 636 | if (obj->userptr.mm->mm == current->mm) { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 637 | pvec = kmalloc(num_pages*sizeof(struct page *), |
| 638 | GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY); |
| 639 | if (pvec == NULL) { |
| 640 | pvec = drm_malloc_ab(num_pages, sizeof(struct page *)); |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 641 | if (pvec == NULL) { |
| 642 | __i915_gem_userptr_set_active(obj, false); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 643 | return -ENOMEM; |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 644 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 645 | } |
| 646 | |
| 647 | pinned = __get_user_pages_fast(obj->userptr.ptr, num_pages, |
| 648 | !obj->userptr.read_only, pvec); |
| 649 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 650 | |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 651 | active = false; |
| 652 | if (pinned < 0) |
| 653 | ret = pinned, pinned = 0; |
| 654 | else if (pinned < num_pages) |
| 655 | ret = __i915_gem_userptr_get_pages_schedule(obj, &active); |
| 656 | else |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 657 | ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages); |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 658 | if (ret) { |
| 659 | __i915_gem_userptr_set_active(obj, active); |
| 660 | release_pages(pvec, pinned, 0); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 661 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 662 | drm_free_large(pvec); |
| 663 | return ret; |
| 664 | } |
| 665 | |
| 666 | static void |
| 667 | i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj) |
| 668 | { |
Tvrtko Ursulin | c479f43 | 2014-09-26 15:05:22 +0100 | [diff] [blame] | 669 | struct sg_page_iter sg_iter; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 670 | |
| 671 | BUG_ON(obj->userptr.work != NULL); |
Chris Wilson | e4b946b | 2015-10-01 12:34:46 +0100 | [diff] [blame] | 672 | __i915_gem_userptr_set_active(obj, false); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 673 | |
| 674 | if (obj->madv != I915_MADV_WILLNEED) |
| 675 | obj->dirty = 0; |
| 676 | |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 677 | i915_gem_gtt_finish_object(obj); |
| 678 | |
Tvrtko Ursulin | c479f43 | 2014-09-26 15:05:22 +0100 | [diff] [blame] | 679 | for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) { |
| 680 | struct page *page = sg_page_iter_page(&sg_iter); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 681 | |
| 682 | if (obj->dirty) |
| 683 | set_page_dirty(page); |
| 684 | |
| 685 | mark_page_accessed(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame^] | 686 | put_page(page); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 687 | } |
| 688 | obj->dirty = 0; |
| 689 | |
| 690 | sg_free_table(obj->pages); |
| 691 | kfree(obj->pages); |
| 692 | } |
| 693 | |
| 694 | static void |
| 695 | i915_gem_userptr_release(struct drm_i915_gem_object *obj) |
| 696 | { |
| 697 | i915_gem_userptr_release__mmu_notifier(obj); |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 698 | i915_gem_userptr_release__mm_struct(obj); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 699 | } |
| 700 | |
| 701 | static int |
| 702 | i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj) |
| 703 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 704 | if (obj->userptr.mmu_object) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 705 | return 0; |
| 706 | |
| 707 | return i915_gem_userptr_init__mmu_notifier(obj, 0); |
| 708 | } |
| 709 | |
| 710 | static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = { |
Chris Wilson | 93232ae | 2016-01-22 18:32:31 +0000 | [diff] [blame] | 711 | .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE, |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 712 | .get_pages = i915_gem_userptr_get_pages, |
| 713 | .put_pages = i915_gem_userptr_put_pages, |
Chris Wilson | 93232ae | 2016-01-22 18:32:31 +0000 | [diff] [blame] | 714 | .dmabuf_export = i915_gem_userptr_dmabuf_export, |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 715 | .release = i915_gem_userptr_release, |
| 716 | }; |
| 717 | |
| 718 | /** |
| 719 | * Creates a new mm object that wraps some normal memory from the process |
| 720 | * context - user memory. |
| 721 | * |
| 722 | * We impose several restrictions upon the memory being mapped |
| 723 | * into the GPU. |
| 724 | * 1. It must be page aligned (both start/end addresses, i.e ptr and size). |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 725 | * 2. It must be normal system memory, not a pointer into another map of IO |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 726 | * space (e.g. it must not be a GTT mmapping of another object). |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 727 | * 3. We only allow a bo as large as we could in theory map into the GTT, |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 728 | * that is we limit the size to the total size of the GTT. |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 729 | * 4. The bo is marked as being snoopable. The backing pages are left |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 730 | * accessible directly by the CPU, but reads and writes by the GPU may |
| 731 | * incur the cost of a snoop (unless you have an LLC architecture). |
| 732 | * |
| 733 | * Synchronisation between multiple users and the GPU is left to userspace |
| 734 | * through the normal set-domain-ioctl. The kernel will enforce that the |
| 735 | * GPU relinquishes the VMA before it is returned back to the system |
| 736 | * i.e. upon free(), munmap() or process termination. However, the userspace |
| 737 | * malloc() library may not immediately relinquish the VMA after free() and |
| 738 | * instead reuse it whilst the GPU is still reading and writing to the VMA. |
| 739 | * Caveat emptor. |
| 740 | * |
| 741 | * Also note, that the object created here is not currently a "first class" |
| 742 | * object, in that several ioctls are banned. These are the CPU access |
| 743 | * ioctls: mmap(), pwrite and pread. In practice, you are expected to use |
Chris Wilson | cc917ab | 2015-10-13 14:22:26 +0100 | [diff] [blame] | 744 | * direct access via your pointer rather than use those ioctls. Another |
| 745 | * restriction is that we do not allow userptr surfaces to be pinned to the |
| 746 | * hardware and so we reject any attempt to create a framebuffer out of a |
| 747 | * userptr. |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 748 | * |
| 749 | * If you think this is a good interface to use to pass GPU memory between |
| 750 | * drivers, please use dma-buf instead. In fact, wherever possible use |
| 751 | * dma-buf instead. |
| 752 | */ |
| 753 | int |
| 754 | i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file) |
| 755 | { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 756 | struct drm_i915_gem_userptr *args = data; |
| 757 | struct drm_i915_gem_object *obj; |
| 758 | int ret; |
| 759 | u32 handle; |
| 760 | |
| 761 | if (args->flags & ~(I915_USERPTR_READ_ONLY | |
| 762 | I915_USERPTR_UNSYNCHRONIZED)) |
| 763 | return -EINVAL; |
| 764 | |
| 765 | if (offset_in_page(args->user_ptr | args->user_size)) |
| 766 | return -EINVAL; |
| 767 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 768 | if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE, |
| 769 | (char __user *)(unsigned long)args->user_ptr, args->user_size)) |
| 770 | return -EFAULT; |
| 771 | |
| 772 | if (args->flags & I915_USERPTR_READ_ONLY) { |
| 773 | /* On almost all of the current hw, we cannot tell the GPU that a |
| 774 | * page is readonly, so this is just a placeholder in the uAPI. |
| 775 | */ |
| 776 | return -ENODEV; |
| 777 | } |
| 778 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 779 | obj = i915_gem_object_alloc(dev); |
| 780 | if (obj == NULL) |
| 781 | return -ENOMEM; |
| 782 | |
| 783 | drm_gem_private_object_init(dev, &obj->base, args->user_size); |
| 784 | i915_gem_object_init(obj, &i915_gem_userptr_ops); |
| 785 | obj->cache_level = I915_CACHE_LLC; |
| 786 | obj->base.write_domain = I915_GEM_DOMAIN_CPU; |
| 787 | obj->base.read_domains = I915_GEM_DOMAIN_CPU; |
| 788 | |
| 789 | obj->userptr.ptr = args->user_ptr; |
| 790 | obj->userptr.read_only = !!(args->flags & I915_USERPTR_READ_ONLY); |
| 791 | |
| 792 | /* And keep a pointer to the current->mm for resolving the user pages |
| 793 | * at binding. This means that we need to hook into the mmu_notifier |
| 794 | * in order to detect if the mmu is destroyed. |
| 795 | */ |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 796 | ret = i915_gem_userptr_init__mm_struct(obj); |
| 797 | if (ret == 0) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 798 | ret = i915_gem_userptr_init__mmu_notifier(obj, args->flags); |
| 799 | if (ret == 0) |
| 800 | ret = drm_gem_handle_create(file, &obj->base, &handle); |
| 801 | |
| 802 | /* drop reference from allocate - handle holds it now */ |
| 803 | drm_gem_object_unreference_unlocked(&obj->base); |
| 804 | if (ret) |
| 805 | return ret; |
| 806 | |
| 807 | args->handle = handle; |
| 808 | return 0; |
| 809 | } |
| 810 | |
| 811 | int |
| 812 | i915_gem_init_userptr(struct drm_device *dev) |
| 813 | { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 814 | struct drm_i915_private *dev_priv = to_i915(dev); |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 815 | mutex_init(&dev_priv->mm_lock); |
| 816 | hash_init(dev_priv->mm_structs); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 817 | return 0; |
| 818 | } |