1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2019 Intel Corporation 5 */ 6 7 #ifndef __I915_GEM_CONTEXT_TYPES_H__ 8 #define __I915_GEM_CONTEXT_TYPES_H__ 9 10 #include <linux/atomic.h> 11 #include <linux/list.h> 12 #include <linux/llist.h> 13 #include <linux/kref.h> 14 #include <linux/mutex.h> 15 #include <linux/radix-tree.h> 16 #include <linux/rbtree.h> 17 #include <linux/rcupdate.h> 18 #include <linux/types.h> 19 20 #include "gt/intel_context_types.h" 21 22 #include "i915_scheduler.h" 23 #include "i915_sw_fence.h" 24 25 struct pid; 26 27 struct drm_i915_private; 28 struct drm_i915_file_private; 29 struct i915_address_space; 30 struct intel_timeline; 31 struct intel_ring; 32 33 /** 34 * struct i915_gem_engines - A set of engines 35 */ 36 struct i915_gem_engines { 37 union { 38 /** @link: Link in i915_gem_context::stale::engines */ 39 struct list_head link; 40 41 /** @rcu: RCU to use when freeing */ 42 struct rcu_head rcu; 43 }; 44 45 /** @fence: Fence used for delayed destruction of engines */ 46 struct i915_sw_fence fence; 47 48 /** @ctx: i915_gem_context backpointer */ 49 struct i915_gem_context *ctx; 50 51 /** @num_engines: Number of engines in this set */ 52 unsigned int num_engines; 53 54 /** @engines: Array of engines */ 55 struct intel_context *engines[]; 56 }; 57 58 /** 59 * struct i915_gem_engines_iter - Iterator for an i915_gem_engines set 60 */ 61 struct i915_gem_engines_iter { 62 /** @idx: Index into i915_gem_engines::engines */ 63 unsigned int idx; 64 65 /** @engines: Engine set being iterated */ 66 const struct i915_gem_engines *engines; 67 }; 68 69 /** 70 * enum i915_gem_engine_type - Describes the type of an i915_gem_proto_engine 71 */ 72 enum i915_gem_engine_type { 73 /** @I915_GEM_ENGINE_TYPE_INVALID: An invalid engine */ 74 I915_GEM_ENGINE_TYPE_INVALID = 0, 75 76 /** @I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine */ 77 I915_GEM_ENGINE_TYPE_PHYSICAL, 78 79 /** @I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set */ 80 I915_GEM_ENGINE_TYPE_BALANCED, 81 82 /** @I915_GEM_ENGINE_TYPE_PARALLEL: A parallel engine set */ 83 I915_GEM_ENGINE_TYPE_PARALLEL, 84 }; 85 86 /** 87 * struct i915_gem_proto_engine - prototype engine 88 * 89 * This struct describes an engine that a context may contain. Engines 90 * have four types: 91 * 92 * - I915_GEM_ENGINE_TYPE_INVALID: Invalid engines can be created but they 93 * show up as a NULL in i915_gem_engines::engines[i] and any attempt to 94 * use them by the user results in -EINVAL. They are also useful during 95 * proto-context construction because the client may create invalid 96 * engines and then set them up later as virtual engines. 97 * 98 * - I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine, described by 99 * i915_gem_proto_engine::engine. 100 * 101 * - I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set, described 102 * i915_gem_proto_engine::num_siblings and i915_gem_proto_engine::siblings. 103 * 104 * - I915_GEM_ENGINE_TYPE_PARALLEL: A parallel submission engine set, described 105 * i915_gem_proto_engine::width, i915_gem_proto_engine::num_siblings, and 106 * i915_gem_proto_engine::siblings. 107 */ 108 struct i915_gem_proto_engine { 109 /** @type: Type of this engine */ 110 enum i915_gem_engine_type type; 111 112 /** @engine: Engine, for physical */ 113 struct intel_engine_cs *engine; 114 115 /** @num_siblings: Number of balanced or parallel siblings */ 116 unsigned int num_siblings; 117 118 /** @width: Width of each sibling */ 119 unsigned int width; 120 121 /** @siblings: Balanced siblings or num_siblings * width for parallel */ 122 struct intel_engine_cs **siblings; 123 124 /** @sseu: Client-set SSEU parameters */ 125 struct intel_sseu sseu; 126 }; 127 128 /** 129 * struct i915_gem_proto_context - prototype context 130 * 131 * The struct i915_gem_proto_context represents the creation parameters for 132 * a struct i915_gem_context. This is used to gather parameters provided 133 * either through creation flags or via SET_CONTEXT_PARAM so that, when we 134 * create the final i915_gem_context, those parameters can be immutable. 135 * 136 * The context uAPI allows for two methods of setting context parameters: 137 * SET_CONTEXT_PARAM and CONTEXT_CREATE_EXT_SETPARAM. The former is 138 * allowed to be called at any time while the later happens as part of 139 * GEM_CONTEXT_CREATE. When these were initially added, Currently, 140 * everything settable via one is settable via the other. While some 141 * params are fairly simple and setting them on a live context is harmless 142 * such the context priority, others are far trickier such as the VM or the 143 * set of engines. To avoid some truly nasty race conditions, we don't 144 * allow setting the VM or the set of engines on live contexts. 145 * 146 * The way we dealt with this without breaking older userspace that sets 147 * the VM or engine set via SET_CONTEXT_PARAM is to delay the creation of 148 * the actual context until after the client is done configuring it with 149 * SET_CONTEXT_PARAM. From the perspective of the client, it has the same 150 * u32 context ID the whole time. From the perspective of i915, however, 151 * it's an i915_gem_proto_context right up until the point where we attempt 152 * to do something which the proto-context can't handle at which point the 153 * real context gets created. 154 * 155 * This is accomplished via a little xarray dance. When GEM_CONTEXT_CREATE 156 * is called, we create a proto-context, reserve a slot in context_xa but 157 * leave it NULL, the proto-context in the corresponding slot in 158 * proto_context_xa. Then, whenever we go to look up a context, we first 159 * check context_xa. If it's there, we return the i915_gem_context and 160 * we're done. If it's not, we look in proto_context_xa and, if we find it 161 * there, we create the actual context and kill the proto-context. 162 * 163 * At the time we made this change (April, 2021), we did a fairly complete 164 * audit of existing userspace to ensure this wouldn't break anything: 165 * 166 * - Mesa/i965 didn't use the engines or VM APIs at all 167 * 168 * - Mesa/ANV used the engines API but via CONTEXT_CREATE_EXT_SETPARAM and 169 * didn't use the VM API. 170 * 171 * - Mesa/iris didn't use the engines or VM APIs at all 172 * 173 * - The open-source compute-runtime didn't yet use the engines API but 174 * did use the VM API via SET_CONTEXT_PARAM. However, CONTEXT_SETPARAM 175 * was always the second ioctl on that context, immediately following 176 * GEM_CONTEXT_CREATE. 177 * 178 * - The media driver sets engines and bonding/balancing via 179 * SET_CONTEXT_PARAM. However, CONTEXT_SETPARAM to set the VM was 180 * always the second ioctl on that context, immediately following 181 * GEM_CONTEXT_CREATE and setting engines immediately followed that. 182 * 183 * In order for this dance to work properly, any modification to an 184 * i915_gem_proto_context that is exposed to the client via 185 * drm_i915_file_private::proto_context_xa must be guarded by 186 * drm_i915_file_private::proto_context_lock. The exception is when a 187 * proto-context has not yet been exposed such as when handling 188 * CONTEXT_CREATE_SET_PARAM during GEM_CONTEXT_CREATE. 189 */ 190 struct i915_gem_proto_context { 191 /** @vm: See &i915_gem_context.vm */ 192 struct i915_address_space *vm; 193 194 /** @user_flags: See &i915_gem_context.user_flags */ 195 unsigned long user_flags; 196 197 /** @sched: See &i915_gem_context.sched */ 198 struct i915_sched_attr sched; 199 200 /** @num_user_engines: Number of user-specified engines or -1 */ 201 int num_user_engines; 202 203 /** @user_engines: User-specified engines */ 204 struct i915_gem_proto_engine *user_engines; 205 206 /** @legacy_rcs_sseu: Client-set SSEU parameters for the legacy RCS */ 207 struct intel_sseu legacy_rcs_sseu; 208 209 /** @single_timeline: See See &i915_gem_context.syncobj */ 210 bool single_timeline; 211 212 /** @uses_protected_content: See &i915_gem_context.uses_protected_content */ 213 bool uses_protected_content; 214 215 /** @pxp_wakeref: See &i915_gem_context.pxp_wakeref */ 216 intel_wakeref_t pxp_wakeref; 217 }; 218 219 /** 220 * struct i915_gem_context - client state 221 * 222 * The struct i915_gem_context represents the combined view of the driver and 223 * logical hardware state for a particular client. 224 */ 225 struct i915_gem_context { 226 /** @i915: i915 device backpointer */ 227 struct drm_i915_private *i915; 228 229 /** @file_priv: owning file descriptor */ 230 struct drm_i915_file_private *file_priv; 231 232 /** 233 * @engines: User defined engines for this context 234 * 235 * Various uAPI offer the ability to lookup up an 236 * index from this array to select an engine operate on. 237 * 238 * Multiple logically distinct instances of the same engine 239 * may be defined in the array, as well as composite virtual 240 * engines. 241 * 242 * Execbuf uses the I915_EXEC_RING_MASK as an index into this 243 * array to select which HW context + engine to execute on. For 244 * the default array, the user_ring_map[] is used to translate 245 * the legacy uABI onto the approprate index (e.g. both 246 * I915_EXEC_DEFAULT and I915_EXEC_RENDER select the same 247 * context, and I915_EXEC_BSD is weird). For a use defined 248 * array, execbuf uses I915_EXEC_RING_MASK as a plain index. 249 * 250 * User defined by I915_CONTEXT_PARAM_ENGINE (when the 251 * CONTEXT_USER_ENGINES flag is set). 252 */ 253 struct i915_gem_engines __rcu *engines; 254 255 /** @engines_mutex: guards writes to engines */ 256 struct mutex engines_mutex; 257 258 /** 259 * @syncobj: Shared timeline syncobj 260 * 261 * When the SHARED_TIMELINE flag is set on context creation, we 262 * emulate a single timeline across all engines using this syncobj. 263 * For every execbuffer2 call, this syncobj is used as both an in- 264 * and out-fence. Unlike the real intel_timeline, this doesn't 265 * provide perfect atomic in-order guarantees if the client races 266 * with itself by calling execbuffer2 twice concurrently. However, 267 * if userspace races with itself, that's not likely to yield well- 268 * defined results anyway so we choose to not care. 269 */ 270 struct drm_syncobj *syncobj; 271 272 /** 273 * @vm: unique address space (GTT) 274 * 275 * In full-ppgtt mode, each context has its own address space ensuring 276 * complete seperation of one client from all others. 277 * 278 * In other modes, this is a NULL pointer with the expectation that 279 * the caller uses the shared global GTT. 280 */ 281 struct i915_address_space *vm; 282 283 /** 284 * @pid: process id of creator 285 * 286 * Note that who created the context may not be the principle user, 287 * as the context may be shared across a local socket. However, 288 * that should only affect the default context, all contexts created 289 * explicitly by the client are expected to be isolated. 290 */ 291 struct pid *pid; 292 293 /** @link: place with &drm_i915_private.context_list */ 294 struct list_head link; 295 296 /** 297 * @ref: reference count 298 * 299 * A reference to a context is held by both the client who created it 300 * and on each request submitted to the hardware using the request 301 * (to ensure the hardware has access to the state until it has 302 * finished all pending writes). See i915_gem_context_get() and 303 * i915_gem_context_put() for access. 304 */ 305 struct kref ref; 306 307 /** 308 * @release_work: 309 * 310 * Work item for deferred cleanup, since i915_gem_context_put() tends to 311 * be called from hardirq context. 312 * 313 * FIXME: The only real reason for this is &i915_gem_engines.fence, all 314 * other callers are from process context and need at most some mild 315 * shuffling to pull the i915_gem_context_put() call out of a spinlock. 316 */ 317 struct work_struct release_work; 318 319 /** 320 * @rcu: rcu_head for deferred freeing. 321 */ 322 struct rcu_head rcu; 323 324 /** 325 * @user_flags: small set of booleans controlled by the user 326 */ 327 unsigned long user_flags; 328 #define UCONTEXT_NO_ERROR_CAPTURE 1 329 #define UCONTEXT_BANNABLE 2 330 #define UCONTEXT_RECOVERABLE 3 331 #define UCONTEXT_PERSISTENCE 4 332 333 /** 334 * @flags: small set of booleans 335 */ 336 unsigned long flags; 337 #define CONTEXT_CLOSED 0 338 #define CONTEXT_USER_ENGINES 1 339 340 /** 341 * @uses_protected_content: context uses PXP-encrypted objects. 342 * 343 * This flag can only be set at ctx creation time and it's immutable for 344 * the lifetime of the context. See I915_CONTEXT_PARAM_PROTECTED_CONTENT 345 * in uapi/drm/i915_drm.h for more info on setting restrictions and 346 * expected behaviour of marked contexts. 347 */ 348 bool uses_protected_content; 349 350 /** 351 * @pxp_wakeref: wakeref to keep the device awake when PXP is in use 352 * 353 * PXP sessions are invalidated when the device is suspended, which in 354 * turns invalidates all contexts and objects using it. To keep the 355 * flow simple, we keep the device awake when contexts using PXP objects 356 * are in use. It is expected that the userspace application only uses 357 * PXP when the display is on, so taking a wakeref here shouldn't worsen 358 * our power metrics. 359 */ 360 intel_wakeref_t pxp_wakeref; 361 362 /** @mutex: guards everything that isn't engines or handles_vma */ 363 struct mutex mutex; 364 365 /** @sched: scheduler parameters */ 366 struct i915_sched_attr sched; 367 368 /** @guilty_count: How many times this context has caused a GPU hang. */ 369 atomic_t guilty_count; 370 /** 371 * @active_count: How many times this context was active during a GPU 372 * hang, but did not cause it. 373 */ 374 atomic_t active_count; 375 376 /** 377 * @hang_timestamp: The last time(s) this context caused a GPU hang 378 */ 379 unsigned long hang_timestamp[2]; 380 #define CONTEXT_FAST_HANG_JIFFIES (120 * HZ) /* 3 hangs within 120s? Banned! */ 381 382 /** @remap_slice: Bitmask of cache lines that need remapping */ 383 u8 remap_slice; 384 385 /** 386 * @handles_vma: rbtree to look up our context specific obj/vma for 387 * the user handle. (user handles are per fd, but the binding is 388 * per vm, which may be one per context or shared with the global GTT) 389 */ 390 struct radix_tree_root handles_vma; 391 392 /** @lut_mutex: Locks handles_vma */ 393 struct mutex lut_mutex; 394 395 /** 396 * @name: arbitrary name, used for user debug 397 * 398 * A name is constructed for the context from the creator's process 399 * name, pid and user handle in order to uniquely identify the 400 * context in messages. 401 */ 402 char name[TASK_COMM_LEN + 8]; 403 404 /** @stale: tracks stale engines to be destroyed */ 405 struct { 406 /** @lock: guards engines */ 407 spinlock_t lock; 408 /** @engines: list of stale engines */ 409 struct list_head engines; 410 } stale; 411 }; 412 413 #endif /* __I915_GEM_CONTEXT_TYPES_H__ */ 414