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 | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 52 | struct list_head linear; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 53 | unsigned long serial; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 54 | bool has_linear; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | struct i915_mmu_object { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 58 | struct i915_mmu_notifier *mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 59 | struct interval_tree_node it; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 60 | struct list_head link; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 61 | struct drm_i915_gem_object *obj; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 62 | bool is_linear; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 63 | }; |
| 64 | |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 65 | static unsigned long cancel_userptr(struct drm_i915_gem_object *obj) |
| 66 | { |
| 67 | struct drm_device *dev = obj->base.dev; |
| 68 | unsigned long end; |
| 69 | |
| 70 | mutex_lock(&dev->struct_mutex); |
| 71 | /* Cancel any active worker and force us to re-evaluate gup */ |
| 72 | obj->userptr.work = NULL; |
| 73 | |
| 74 | if (obj->pages != NULL) { |
| 75 | struct drm_i915_private *dev_priv = to_i915(dev); |
| 76 | struct i915_vma *vma, *tmp; |
| 77 | bool was_interruptible; |
| 78 | |
| 79 | was_interruptible = dev_priv->mm.interruptible; |
| 80 | dev_priv->mm.interruptible = false; |
| 81 | |
| 82 | list_for_each_entry_safe(vma, tmp, &obj->vma_list, vma_link) { |
| 83 | int ret = i915_vma_unbind(vma); |
| 84 | WARN_ON(ret && ret != -EIO); |
| 85 | } |
| 86 | WARN_ON(i915_gem_object_put_pages(obj)); |
| 87 | |
| 88 | dev_priv->mm.interruptible = was_interruptible; |
| 89 | } |
| 90 | |
| 91 | end = obj->userptr.ptr + obj->base.size; |
| 92 | |
| 93 | drm_gem_object_unreference(&obj->base); |
| 94 | mutex_unlock(&dev->struct_mutex); |
| 95 | |
| 96 | return end; |
| 97 | } |
| 98 | |
Chris Wilson | 4877776 | 2014-07-24 13:28:44 +0100 | [diff] [blame] | 99 | static void *invalidate_range__linear(struct i915_mmu_notifier *mn, |
| 100 | struct mm_struct *mm, |
| 101 | unsigned long start, |
| 102 | unsigned long end) |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 103 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 104 | struct i915_mmu_object *mo; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 105 | unsigned long serial; |
| 106 | |
| 107 | restart: |
| 108 | serial = mn->serial; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 109 | list_for_each_entry(mo, &mn->linear, link) { |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 110 | struct drm_i915_gem_object *obj; |
| 111 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 112 | if (mo->it.last < start || mo->it.start > end) |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 113 | continue; |
| 114 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 115 | obj = mo->obj; |
Michał Winiarski | 460822b | 2015-02-03 15:48:17 +0100 | [diff] [blame] | 116 | |
| 117 | if (!kref_get_unless_zero(&obj->base.refcount)) |
| 118 | continue; |
| 119 | |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 120 | spin_unlock(&mn->lock); |
| 121 | |
| 122 | cancel_userptr(obj); |
| 123 | |
| 124 | spin_lock(&mn->lock); |
| 125 | if (serial != mn->serial) |
| 126 | goto restart; |
| 127 | } |
| 128 | |
Chris Wilson | 4877776 | 2014-07-24 13:28:44 +0100 | [diff] [blame] | 129 | return NULL; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 130 | } |
| 131 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 132 | static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, |
| 133 | struct mm_struct *mm, |
| 134 | unsigned long start, |
| 135 | unsigned long end) |
| 136 | { |
| 137 | struct i915_mmu_notifier *mn = container_of(_mn, struct i915_mmu_notifier, mn); |
| 138 | struct interval_tree_node *it = NULL; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 139 | unsigned long next = start; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 140 | unsigned long serial = 0; |
| 141 | |
| 142 | end--; /* interval ranges are inclusive, but invalidate range is exclusive */ |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 143 | while (next < end) { |
Chris Wilson | 4877776 | 2014-07-24 13:28:44 +0100 | [diff] [blame] | 144 | struct drm_i915_gem_object *obj = NULL; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 145 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 146 | spin_lock(&mn->lock); |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 147 | if (mn->has_linear) |
Chris Wilson | 4877776 | 2014-07-24 13:28:44 +0100 | [diff] [blame] | 148 | it = invalidate_range__linear(mn, mm, start, end); |
| 149 | else if (serial == mn->serial) |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 150 | it = interval_tree_iter_next(it, next, end); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 151 | else |
| 152 | it = interval_tree_iter_first(&mn->objects, start, end); |
| 153 | if (it != NULL) { |
| 154 | obj = container_of(it, struct i915_mmu_object, it)->obj; |
Michał Winiarski | 460822b | 2015-02-03 15:48:17 +0100 | [diff] [blame] | 155 | |
| 156 | /* The mmu_object is released late when destroying the |
| 157 | * GEM object so it is entirely possible to gain a |
| 158 | * reference on an object in the process of being freed |
| 159 | * since our serialisation is via the spinlock and not |
| 160 | * the struct_mutex - and consequently use it after it |
| 161 | * is freed and then double free it. |
| 162 | */ |
| 163 | if (!kref_get_unless_zero(&obj->base.refcount)) { |
| 164 | spin_unlock(&mn->lock); |
| 165 | serial = 0; |
| 166 | continue; |
| 167 | } |
| 168 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 169 | serial = mn->serial; |
| 170 | } |
| 171 | spin_unlock(&mn->lock); |
| 172 | if (obj == NULL) |
| 173 | return; |
| 174 | |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 175 | next = cancel_userptr(obj); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 176 | } |
| 177 | } |
| 178 | |
| 179 | static const struct mmu_notifier_ops i915_gem_userptr_notifier = { |
| 180 | .invalidate_range_start = i915_gem_userptr_mn_invalidate_range_start, |
| 181 | }; |
| 182 | |
| 183 | static struct i915_mmu_notifier * |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 184 | i915_mmu_notifier_create(struct mm_struct *mm) |
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 | struct i915_mmu_notifier *mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 187 | int ret; |
| 188 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 189 | mn = kmalloc(sizeof(*mn), GFP_KERNEL); |
| 190 | if (mn == NULL) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 191 | return ERR_PTR(-ENOMEM); |
| 192 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 193 | spin_lock_init(&mn->lock); |
| 194 | mn->mn.ops = &i915_gem_userptr_notifier; |
| 195 | mn->objects = RB_ROOT; |
| 196 | mn->serial = 1; |
| 197 | INIT_LIST_HEAD(&mn->linear); |
| 198 | mn->has_linear = false; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 199 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 200 | /* Protected by mmap_sem (write-lock) */ |
| 201 | ret = __mmu_notifier_register(&mn->mn, mm); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 202 | if (ret) { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 203 | kfree(mn); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 204 | return ERR_PTR(ret); |
| 205 | } |
| 206 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 207 | return mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 208 | } |
| 209 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 210 | static void __i915_mmu_notifier_update_serial(struct i915_mmu_notifier *mn) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 211 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 212 | if (++mn->serial == 0) |
| 213 | mn->serial = 1; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 214 | } |
| 215 | |
| 216 | static int |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 217 | i915_mmu_notifier_add(struct drm_device *dev, |
| 218 | struct i915_mmu_notifier *mn, |
| 219 | struct i915_mmu_object *mo) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 220 | { |
| 221 | struct interval_tree_node *it; |
Chris Wilson | 281400f | 2015-05-15 11:42:21 +0100 | [diff] [blame] | 222 | int ret = 0; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 223 | |
Chris Wilson | 281400f | 2015-05-15 11:42:21 +0100 | [diff] [blame] | 224 | /* By this point we have already done a lot of expensive setup that |
| 225 | * we do not want to repeat just because the caller (e.g. X) has a |
| 226 | * signal pending (and partly because of that expensive setup, X |
| 227 | * using an interrupt timer is likely to get stuck in an EINTR loop). |
| 228 | */ |
| 229 | mutex_lock(&dev->struct_mutex); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 230 | |
| 231 | /* Make sure we drop the final active reference (and thereby |
| 232 | * remove the objects from the interval tree) before we do |
| 233 | * the check for overlapping objects. |
| 234 | */ |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 235 | i915_gem_retire_requests(dev); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 236 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 237 | spin_lock(&mn->lock); |
| 238 | it = interval_tree_iter_first(&mn->objects, |
| 239 | mo->it.start, mo->it.last); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 240 | if (it) { |
| 241 | struct drm_i915_gem_object *obj; |
| 242 | |
| 243 | /* We only need to check the first object in the range as it |
| 244 | * either has cancelled gup work queued and we need to |
| 245 | * return back to the user to give time for the gup-workers |
| 246 | * to flush their object references upon which the object will |
| 247 | * be removed from the interval-tree, or the the range is |
| 248 | * still in use by another client and the overlap is invalid. |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 249 | * |
| 250 | * If we do have an overlap, we cannot use the interval tree |
| 251 | * for fast range invalidation. |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 252 | */ |
| 253 | |
| 254 | obj = container_of(it, struct i915_mmu_object, it)->obj; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 255 | if (!obj->userptr.workers) |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 256 | mn->has_linear = mo->is_linear = true; |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 257 | else |
| 258 | ret = -EAGAIN; |
| 259 | } else |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 260 | interval_tree_insert(&mo->it, &mn->objects); |
Chris Wilson | ec8b0dd | 2014-07-21 13:21:23 +0100 | [diff] [blame] | 261 | |
| 262 | if (ret == 0) { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 263 | list_add(&mo->link, &mn->linear); |
| 264 | __i915_mmu_notifier_update_serial(mn); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 265 | } |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 266 | spin_unlock(&mn->lock); |
| 267 | mutex_unlock(&dev->struct_mutex); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 268 | |
| 269 | return ret; |
| 270 | } |
| 271 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 272 | static bool i915_mmu_notifier_has_linear(struct i915_mmu_notifier *mn) |
| 273 | { |
| 274 | struct i915_mmu_object *mo; |
| 275 | |
| 276 | list_for_each_entry(mo, &mn->linear, link) |
| 277 | if (mo->is_linear) |
| 278 | return true; |
| 279 | |
| 280 | return false; |
| 281 | } |
| 282 | |
| 283 | static void |
| 284 | i915_mmu_notifier_del(struct i915_mmu_notifier *mn, |
| 285 | struct i915_mmu_object *mo) |
| 286 | { |
| 287 | spin_lock(&mn->lock); |
| 288 | list_del(&mo->link); |
| 289 | if (mo->is_linear) |
| 290 | mn->has_linear = i915_mmu_notifier_has_linear(mn); |
| 291 | else |
| 292 | interval_tree_remove(&mo->it, &mn->objects); |
| 293 | __i915_mmu_notifier_update_serial(mn); |
| 294 | spin_unlock(&mn->lock); |
| 295 | } |
| 296 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 297 | static void |
| 298 | i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) |
| 299 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 300 | struct i915_mmu_object *mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 301 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 302 | mo = obj->userptr.mmu_object; |
| 303 | if (mo == NULL) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 304 | return; |
| 305 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 306 | i915_mmu_notifier_del(mo->mn, mo); |
| 307 | kfree(mo); |
| 308 | |
| 309 | obj->userptr.mmu_object = NULL; |
| 310 | } |
| 311 | |
| 312 | static struct i915_mmu_notifier * |
| 313 | i915_mmu_notifier_find(struct i915_mm_struct *mm) |
| 314 | { |
Chris Wilson | e968136 | 2014-09-26 10:31:02 +0100 | [diff] [blame] | 315 | struct i915_mmu_notifier *mn = mm->mn; |
| 316 | |
| 317 | mn = mm->mn; |
| 318 | if (mn) |
| 319 | return mn; |
| 320 | |
| 321 | down_write(&mm->mm->mmap_sem); |
| 322 | mutex_lock(&to_i915(mm->dev)->mm_lock); |
| 323 | if ((mn = mm->mn) == NULL) { |
| 324 | mn = i915_mmu_notifier_create(mm->mm); |
| 325 | if (!IS_ERR(mn)) |
| 326 | mm->mn = mn; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 327 | } |
Chris Wilson | e968136 | 2014-09-26 10:31:02 +0100 | [diff] [blame] | 328 | mutex_unlock(&to_i915(mm->dev)->mm_lock); |
| 329 | up_write(&mm->mm->mmap_sem); |
| 330 | |
| 331 | return mn; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 332 | } |
| 333 | |
| 334 | static int |
| 335 | i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, |
| 336 | unsigned flags) |
| 337 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 338 | struct i915_mmu_notifier *mn; |
| 339 | struct i915_mmu_object *mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 340 | int ret; |
| 341 | |
| 342 | if (flags & I915_USERPTR_UNSYNCHRONIZED) |
| 343 | return capable(CAP_SYS_ADMIN) ? 0 : -EPERM; |
| 344 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 345 | if (WARN_ON(obj->userptr.mm == NULL)) |
| 346 | return -EINVAL; |
| 347 | |
| 348 | mn = i915_mmu_notifier_find(obj->userptr.mm); |
| 349 | if (IS_ERR(mn)) |
| 350 | return PTR_ERR(mn); |
| 351 | |
| 352 | mo = kzalloc(sizeof(*mo), GFP_KERNEL); |
| 353 | if (mo == NULL) |
| 354 | return -ENOMEM; |
| 355 | |
| 356 | mo->mn = mn; |
| 357 | mo->it.start = obj->userptr.ptr; |
| 358 | mo->it.last = mo->it.start + obj->base.size - 1; |
| 359 | mo->obj = obj; |
| 360 | |
| 361 | ret = i915_mmu_notifier_add(obj->base.dev, mn, mo); |
| 362 | if (ret) { |
| 363 | kfree(mo); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 364 | return ret; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 365 | } |
| 366 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 367 | obj->userptr.mmu_object = mo; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 368 | return 0; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 369 | } |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 370 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 371 | static void |
| 372 | i915_mmu_notifier_free(struct i915_mmu_notifier *mn, |
| 373 | struct mm_struct *mm) |
| 374 | { |
| 375 | if (mn == NULL) |
| 376 | return; |
| 377 | |
| 378 | mmu_notifier_unregister(&mn->mn, mm); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 379 | kfree(mn); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 380 | } |
| 381 | |
| 382 | #else |
| 383 | |
| 384 | static void |
| 385 | i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) |
| 386 | { |
| 387 | } |
| 388 | |
| 389 | static int |
| 390 | i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, |
| 391 | unsigned flags) |
| 392 | { |
| 393 | if ((flags & I915_USERPTR_UNSYNCHRONIZED) == 0) |
| 394 | return -ENODEV; |
| 395 | |
| 396 | if (!capable(CAP_SYS_ADMIN)) |
| 397 | return -EPERM; |
| 398 | |
| 399 | return 0; |
| 400 | } |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 401 | |
| 402 | static void |
| 403 | i915_mmu_notifier_free(struct i915_mmu_notifier *mn, |
| 404 | struct mm_struct *mm) |
| 405 | { |
| 406 | } |
| 407 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 408 | #endif |
| 409 | |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 410 | static struct i915_mm_struct * |
| 411 | __i915_mm_struct_find(struct drm_i915_private *dev_priv, struct mm_struct *real) |
| 412 | { |
| 413 | struct i915_mm_struct *mm; |
| 414 | |
| 415 | /* Protected by dev_priv->mm_lock */ |
| 416 | hash_for_each_possible(dev_priv->mm_structs, mm, node, (unsigned long)real) |
| 417 | if (mm->mm == real) |
| 418 | return mm; |
| 419 | |
| 420 | return NULL; |
| 421 | } |
| 422 | |
| 423 | static int |
| 424 | i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj) |
| 425 | { |
| 426 | struct drm_i915_private *dev_priv = to_i915(obj->base.dev); |
| 427 | struct i915_mm_struct *mm; |
| 428 | int ret = 0; |
| 429 | |
| 430 | /* During release of the GEM object we hold the struct_mutex. This |
| 431 | * precludes us from calling mmput() at that time as that may be |
| 432 | * the last reference and so call exit_mmap(). exit_mmap() will |
| 433 | * attempt to reap the vma, and if we were holding a GTT mmap |
| 434 | * would then call drm_gem_vm_close() and attempt to reacquire |
| 435 | * the struct mutex. So in order to avoid that recursion, we have |
| 436 | * to defer releasing the mm reference until after we drop the |
| 437 | * struct_mutex, i.e. we need to schedule a worker to do the clean |
| 438 | * up. |
| 439 | */ |
| 440 | mutex_lock(&dev_priv->mm_lock); |
| 441 | mm = __i915_mm_struct_find(dev_priv, current->mm); |
| 442 | if (mm == NULL) { |
| 443 | mm = kmalloc(sizeof(*mm), GFP_KERNEL); |
| 444 | if (mm == NULL) { |
| 445 | ret = -ENOMEM; |
| 446 | goto out; |
| 447 | } |
| 448 | |
| 449 | kref_init(&mm->kref); |
| 450 | mm->dev = obj->base.dev; |
| 451 | |
| 452 | mm->mm = current->mm; |
| 453 | atomic_inc(¤t->mm->mm_count); |
| 454 | |
| 455 | mm->mn = NULL; |
| 456 | |
| 457 | /* Protected by dev_priv->mm_lock */ |
| 458 | hash_add(dev_priv->mm_structs, |
| 459 | &mm->node, (unsigned long)mm->mm); |
| 460 | } else |
| 461 | kref_get(&mm->kref); |
| 462 | |
| 463 | obj->userptr.mm = mm; |
| 464 | out: |
| 465 | mutex_unlock(&dev_priv->mm_lock); |
| 466 | return ret; |
| 467 | } |
| 468 | |
| 469 | static void |
| 470 | __i915_mm_struct_free__worker(struct work_struct *work) |
| 471 | { |
| 472 | struct i915_mm_struct *mm = container_of(work, typeof(*mm), work); |
| 473 | i915_mmu_notifier_free(mm->mn, mm->mm); |
| 474 | mmdrop(mm->mm); |
| 475 | kfree(mm); |
| 476 | } |
| 477 | |
| 478 | static void |
| 479 | __i915_mm_struct_free(struct kref *kref) |
| 480 | { |
| 481 | struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref); |
| 482 | |
| 483 | /* Protected by dev_priv->mm_lock */ |
| 484 | hash_del(&mm->node); |
| 485 | mutex_unlock(&to_i915(mm->dev)->mm_lock); |
| 486 | |
| 487 | INIT_WORK(&mm->work, __i915_mm_struct_free__worker); |
| 488 | schedule_work(&mm->work); |
| 489 | } |
| 490 | |
| 491 | static void |
| 492 | i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj) |
| 493 | { |
| 494 | if (obj->userptr.mm == NULL) |
| 495 | return; |
| 496 | |
| 497 | kref_put_mutex(&obj->userptr.mm->kref, |
| 498 | __i915_mm_struct_free, |
| 499 | &to_i915(obj->base.dev)->mm_lock); |
| 500 | obj->userptr.mm = NULL; |
| 501 | } |
| 502 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 503 | struct get_pages_work { |
| 504 | struct work_struct work; |
| 505 | struct drm_i915_gem_object *obj; |
| 506 | struct task_struct *task; |
| 507 | }; |
| 508 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 509 | #if IS_ENABLED(CONFIG_SWIOTLB) |
| 510 | #define swiotlb_active() swiotlb_nr_tbl() |
| 511 | #else |
| 512 | #define swiotlb_active() 0 |
| 513 | #endif |
| 514 | |
| 515 | static int |
| 516 | st_set_pages(struct sg_table **st, struct page **pvec, int num_pages) |
| 517 | { |
| 518 | struct scatterlist *sg; |
| 519 | int ret, n; |
| 520 | |
| 521 | *st = kmalloc(sizeof(**st), GFP_KERNEL); |
| 522 | if (*st == NULL) |
| 523 | return -ENOMEM; |
| 524 | |
| 525 | if (swiotlb_active()) { |
| 526 | ret = sg_alloc_table(*st, num_pages, GFP_KERNEL); |
| 527 | if (ret) |
| 528 | goto err; |
| 529 | |
| 530 | for_each_sg((*st)->sgl, sg, num_pages, n) |
| 531 | sg_set_page(sg, pvec[n], PAGE_SIZE, 0); |
| 532 | } else { |
| 533 | ret = sg_alloc_table_from_pages(*st, pvec, num_pages, |
| 534 | 0, num_pages << PAGE_SHIFT, |
| 535 | GFP_KERNEL); |
| 536 | if (ret) |
| 537 | goto err; |
| 538 | } |
| 539 | |
| 540 | return 0; |
| 541 | |
| 542 | err: |
| 543 | kfree(*st); |
| 544 | *st = NULL; |
| 545 | return ret; |
| 546 | } |
| 547 | |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 548 | static int |
| 549 | __i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj, |
| 550 | struct page **pvec, int num_pages) |
| 551 | { |
| 552 | int ret; |
| 553 | |
| 554 | ret = st_set_pages(&obj->pages, pvec, num_pages); |
| 555 | if (ret) |
| 556 | return ret; |
| 557 | |
| 558 | ret = i915_gem_gtt_prepare_object(obj); |
| 559 | if (ret) { |
| 560 | sg_free_table(obj->pages); |
| 561 | kfree(obj->pages); |
| 562 | obj->pages = NULL; |
| 563 | } |
| 564 | |
| 565 | return ret; |
| 566 | } |
| 567 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 568 | static void |
| 569 | __i915_gem_userptr_get_pages_worker(struct work_struct *_work) |
| 570 | { |
| 571 | struct get_pages_work *work = container_of(_work, typeof(*work), work); |
| 572 | struct drm_i915_gem_object *obj = work->obj; |
| 573 | struct drm_device *dev = obj->base.dev; |
| 574 | const int num_pages = obj->base.size >> PAGE_SHIFT; |
| 575 | struct page **pvec; |
| 576 | int pinned, ret; |
| 577 | |
| 578 | ret = -ENOMEM; |
| 579 | pinned = 0; |
| 580 | |
| 581 | pvec = kmalloc(num_pages*sizeof(struct page *), |
| 582 | GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY); |
| 583 | if (pvec == NULL) |
| 584 | pvec = drm_malloc_ab(num_pages, sizeof(struct page *)); |
| 585 | if (pvec != NULL) { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 586 | struct mm_struct *mm = obj->userptr.mm->mm; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 587 | |
| 588 | down_read(&mm->mmap_sem); |
| 589 | while (pinned < num_pages) { |
| 590 | ret = get_user_pages(work->task, mm, |
| 591 | obj->userptr.ptr + pinned * PAGE_SIZE, |
| 592 | num_pages - pinned, |
| 593 | !obj->userptr.read_only, 0, |
| 594 | pvec + pinned, NULL); |
| 595 | if (ret < 0) |
| 596 | break; |
| 597 | |
| 598 | pinned += ret; |
| 599 | } |
| 600 | up_read(&mm->mmap_sem); |
| 601 | } |
| 602 | |
| 603 | mutex_lock(&dev->struct_mutex); |
| 604 | if (obj->userptr.work != &work->work) { |
| 605 | ret = 0; |
| 606 | } else if (pinned == num_pages) { |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 607 | ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 608 | if (ret == 0) { |
| 609 | list_add_tail(&obj->global_list, &to_i915(dev)->mm.unbound_list); |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 610 | obj->get_page.sg = obj->pages->sgl; |
| 611 | obj->get_page.last = 0; |
| 612 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 613 | pinned = 0; |
| 614 | } |
| 615 | } |
| 616 | |
| 617 | obj->userptr.work = ERR_PTR(ret); |
| 618 | obj->userptr.workers--; |
| 619 | drm_gem_object_unreference(&obj->base); |
| 620 | mutex_unlock(&dev->struct_mutex); |
| 621 | |
| 622 | release_pages(pvec, pinned, 0); |
| 623 | drm_free_large(pvec); |
| 624 | |
| 625 | put_task_struct(work->task); |
| 626 | kfree(work); |
| 627 | } |
| 628 | |
| 629 | static int |
| 630 | i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) |
| 631 | { |
| 632 | const int num_pages = obj->base.size >> PAGE_SHIFT; |
| 633 | struct page **pvec; |
| 634 | int pinned, ret; |
| 635 | |
| 636 | /* If userspace should engineer that these pages are replaced in |
| 637 | * the vma between us binding this page into the GTT and completion |
| 638 | * of rendering... Their loss. If they change the mapping of their |
| 639 | * pages they need to create a new bo to point to the new vma. |
| 640 | * |
| 641 | * However, that still leaves open the possibility of the vma |
| 642 | * being copied upon fork. Which falls under the same userspace |
| 643 | * synchronisation issue as a regular bo, except that this time |
| 644 | * the process may not be expecting that a particular piece of |
| 645 | * memory is tied to the GPU. |
| 646 | * |
| 647 | * Fortunately, we can hook into the mmu_notifier in order to |
| 648 | * discard the page references prior to anything nasty happening |
| 649 | * to the vma (discard or cloning) which should prevent the more |
| 650 | * egregious cases from causing harm. |
| 651 | */ |
| 652 | |
| 653 | pvec = NULL; |
| 654 | pinned = 0; |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 655 | if (obj->userptr.mm->mm == current->mm) { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 656 | pvec = kmalloc(num_pages*sizeof(struct page *), |
| 657 | GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY); |
| 658 | if (pvec == NULL) { |
| 659 | pvec = drm_malloc_ab(num_pages, sizeof(struct page *)); |
| 660 | if (pvec == NULL) |
| 661 | return -ENOMEM; |
| 662 | } |
| 663 | |
| 664 | pinned = __get_user_pages_fast(obj->userptr.ptr, num_pages, |
| 665 | !obj->userptr.read_only, pvec); |
| 666 | } |
| 667 | if (pinned < num_pages) { |
| 668 | if (pinned < 0) { |
| 669 | ret = pinned; |
| 670 | pinned = 0; |
| 671 | } else { |
| 672 | /* Spawn a worker so that we can acquire the |
| 673 | * user pages without holding our mutex. Access |
| 674 | * to the user pages requires mmap_sem, and we have |
| 675 | * a strict lock ordering of mmap_sem, struct_mutex - |
| 676 | * we already hold struct_mutex here and so cannot |
| 677 | * call gup without encountering a lock inversion. |
| 678 | * |
| 679 | * Userspace will keep on repeating the operation |
| 680 | * (thanks to EAGAIN) until either we hit the fast |
| 681 | * path or the worker completes. If the worker is |
| 682 | * cancelled or superseded, the task is still run |
| 683 | * but the results ignored. (This leads to |
| 684 | * complications that we may have a stray object |
| 685 | * refcount that we need to be wary of when |
| 686 | * checking for existing objects during creation.) |
| 687 | * If the worker encounters an error, it reports |
| 688 | * that error back to this function through |
| 689 | * obj->userptr.work = ERR_PTR. |
| 690 | */ |
| 691 | ret = -EAGAIN; |
| 692 | if (obj->userptr.work == NULL && |
| 693 | obj->userptr.workers < I915_GEM_USERPTR_MAX_WORKERS) { |
| 694 | struct get_pages_work *work; |
| 695 | |
| 696 | work = kmalloc(sizeof(*work), GFP_KERNEL); |
| 697 | if (work != NULL) { |
| 698 | obj->userptr.work = &work->work; |
| 699 | obj->userptr.workers++; |
| 700 | |
| 701 | work->obj = obj; |
| 702 | drm_gem_object_reference(&obj->base); |
| 703 | |
| 704 | work->task = current; |
| 705 | get_task_struct(work->task); |
| 706 | |
| 707 | INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker); |
| 708 | schedule_work(&work->work); |
| 709 | } else |
| 710 | ret = -ENOMEM; |
| 711 | } else { |
| 712 | if (IS_ERR(obj->userptr.work)) { |
| 713 | ret = PTR_ERR(obj->userptr.work); |
| 714 | obj->userptr.work = NULL; |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | } else { |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 719 | ret = __i915_gem_userptr_set_pages(obj, pvec, num_pages); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 720 | if (ret == 0) { |
| 721 | obj->userptr.work = NULL; |
| 722 | pinned = 0; |
| 723 | } |
| 724 | } |
| 725 | |
| 726 | release_pages(pvec, pinned, 0); |
| 727 | drm_free_large(pvec); |
| 728 | return ret; |
| 729 | } |
| 730 | |
| 731 | static void |
| 732 | i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj) |
| 733 | { |
Tvrtko Ursulin | c479f43 | 2014-09-26 15:05:22 +0100 | [diff] [blame] | 734 | struct sg_page_iter sg_iter; |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 735 | |
| 736 | BUG_ON(obj->userptr.work != NULL); |
| 737 | |
| 738 | if (obj->madv != I915_MADV_WILLNEED) |
| 739 | obj->dirty = 0; |
| 740 | |
Imre Deak | e227330 | 2015-07-09 12:59:05 +0300 | [diff] [blame] | 741 | i915_gem_gtt_finish_object(obj); |
| 742 | |
Tvrtko Ursulin | c479f43 | 2014-09-26 15:05:22 +0100 | [diff] [blame] | 743 | for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) { |
| 744 | struct page *page = sg_page_iter_page(&sg_iter); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 745 | |
| 746 | if (obj->dirty) |
| 747 | set_page_dirty(page); |
| 748 | |
| 749 | mark_page_accessed(page); |
| 750 | page_cache_release(page); |
| 751 | } |
| 752 | obj->dirty = 0; |
| 753 | |
| 754 | sg_free_table(obj->pages); |
| 755 | kfree(obj->pages); |
| 756 | } |
| 757 | |
| 758 | static void |
| 759 | i915_gem_userptr_release(struct drm_i915_gem_object *obj) |
| 760 | { |
| 761 | i915_gem_userptr_release__mmu_notifier(obj); |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 762 | i915_gem_userptr_release__mm_struct(obj); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 763 | } |
| 764 | |
| 765 | static int |
| 766 | i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj) |
| 767 | { |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 768 | if (obj->userptr.mmu_object) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 769 | return 0; |
| 770 | |
| 771 | return i915_gem_userptr_init__mmu_notifier(obj, 0); |
| 772 | } |
| 773 | |
| 774 | static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = { |
| 775 | .dmabuf_export = i915_gem_userptr_dmabuf_export, |
| 776 | .get_pages = i915_gem_userptr_get_pages, |
| 777 | .put_pages = i915_gem_userptr_put_pages, |
| 778 | .release = i915_gem_userptr_release, |
| 779 | }; |
| 780 | |
| 781 | /** |
| 782 | * Creates a new mm object that wraps some normal memory from the process |
| 783 | * context - user memory. |
| 784 | * |
| 785 | * We impose several restrictions upon the memory being mapped |
| 786 | * into the GPU. |
| 787 | * 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] | 788 | * 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] | 789 | * 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] | 790 | * 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] | 791 | * 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] | 792 | * 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] | 793 | * accessible directly by the CPU, but reads and writes by the GPU may |
| 794 | * incur the cost of a snoop (unless you have an LLC architecture). |
| 795 | * |
| 796 | * Synchronisation between multiple users and the GPU is left to userspace |
| 797 | * through the normal set-domain-ioctl. The kernel will enforce that the |
| 798 | * GPU relinquishes the VMA before it is returned back to the system |
| 799 | * i.e. upon free(), munmap() or process termination. However, the userspace |
| 800 | * malloc() library may not immediately relinquish the VMA after free() and |
| 801 | * instead reuse it whilst the GPU is still reading and writing to the VMA. |
| 802 | * Caveat emptor. |
| 803 | * |
| 804 | * Also note, that the object created here is not currently a "first class" |
| 805 | * object, in that several ioctls are banned. These are the CPU access |
| 806 | * ioctls: mmap(), pwrite and pread. In practice, you are expected to use |
| 807 | * direct access via your pointer rather than use those ioctls. |
| 808 | * |
| 809 | * If you think this is a good interface to use to pass GPU memory between |
| 810 | * drivers, please use dma-buf instead. In fact, wherever possible use |
| 811 | * dma-buf instead. |
| 812 | */ |
| 813 | int |
| 814 | i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file) |
| 815 | { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 816 | struct drm_i915_gem_userptr *args = data; |
| 817 | struct drm_i915_gem_object *obj; |
| 818 | int ret; |
| 819 | u32 handle; |
| 820 | |
| 821 | if (args->flags & ~(I915_USERPTR_READ_ONLY | |
| 822 | I915_USERPTR_UNSYNCHRONIZED)) |
| 823 | return -EINVAL; |
| 824 | |
| 825 | if (offset_in_page(args->user_ptr | args->user_size)) |
| 826 | return -EINVAL; |
| 827 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 828 | if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE, |
| 829 | (char __user *)(unsigned long)args->user_ptr, args->user_size)) |
| 830 | return -EFAULT; |
| 831 | |
| 832 | if (args->flags & I915_USERPTR_READ_ONLY) { |
| 833 | /* On almost all of the current hw, we cannot tell the GPU that a |
| 834 | * page is readonly, so this is just a placeholder in the uAPI. |
| 835 | */ |
| 836 | return -ENODEV; |
| 837 | } |
| 838 | |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 839 | obj = i915_gem_object_alloc(dev); |
| 840 | if (obj == NULL) |
| 841 | return -ENOMEM; |
| 842 | |
| 843 | drm_gem_private_object_init(dev, &obj->base, args->user_size); |
| 844 | i915_gem_object_init(obj, &i915_gem_userptr_ops); |
| 845 | obj->cache_level = I915_CACHE_LLC; |
| 846 | obj->base.write_domain = I915_GEM_DOMAIN_CPU; |
| 847 | obj->base.read_domains = I915_GEM_DOMAIN_CPU; |
| 848 | |
| 849 | obj->userptr.ptr = args->user_ptr; |
| 850 | obj->userptr.read_only = !!(args->flags & I915_USERPTR_READ_ONLY); |
| 851 | |
| 852 | /* And keep a pointer to the current->mm for resolving the user pages |
| 853 | * at binding. This means that we need to hook into the mmu_notifier |
| 854 | * in order to detect if the mmu is destroyed. |
| 855 | */ |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 856 | ret = i915_gem_userptr_init__mm_struct(obj); |
| 857 | if (ret == 0) |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 858 | ret = i915_gem_userptr_init__mmu_notifier(obj, args->flags); |
| 859 | if (ret == 0) |
| 860 | ret = drm_gem_handle_create(file, &obj->base, &handle); |
| 861 | |
| 862 | /* drop reference from allocate - handle holds it now */ |
| 863 | drm_gem_object_unreference_unlocked(&obj->base); |
| 864 | if (ret) |
| 865 | return ret; |
| 866 | |
| 867 | args->handle = handle; |
| 868 | return 0; |
| 869 | } |
| 870 | |
| 871 | int |
| 872 | i915_gem_init_userptr(struct drm_device *dev) |
| 873 | { |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 874 | struct drm_i915_private *dev_priv = to_i915(dev); |
Chris Wilson | ad46cb5 | 2014-08-07 14:20:40 +0100 | [diff] [blame] | 875 | mutex_init(&dev_priv->mm_lock); |
| 876 | hash_init(dev_priv->mm_structs); |
Chris Wilson | 5cc9ed4 | 2014-05-16 14:22:37 +0100 | [diff] [blame] | 877 | return 0; |
| 878 | } |