2 * SPDX-License-Identifier: MIT
4 * Copyright © 2019 Intel Corporation
7 #ifndef __I915_GEM_CONTEXT_TYPES_H__
8 #define __I915_GEM_CONTEXT_TYPES_H__
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>
20 #include "gt/intel_context_types.h"
22 #include "i915_scheduler.h"
23 #include "i915_sw_fence.h"
27 struct drm_i915_private;
28 struct drm_i915_file_private;
29 struct i915_address_space;
30 struct intel_timeline;
34 * struct i915_gem_engines - A set of engines
36 struct i915_gem_engines {
38 /** @link: Link in i915_gem_context::stale::engines */
39 struct list_head link;
41 /** @rcu: RCU to use when freeing */
45 /** @fence: Fence used for delayed destruction of engines */
46 struct i915_sw_fence fence;
48 /** @ctx: i915_gem_context backpointer */
49 struct i915_gem_context *ctx;
51 /** @num_engines: Number of engines in this set */
52 unsigned int num_engines;
54 /** @engines: Array of engines */
55 struct intel_context *engines[];
59 * struct i915_gem_engines_iter - Iterator for an i915_gem_engines set
61 struct i915_gem_engines_iter {
62 /** @idx: Index into i915_gem_engines::engines */
65 /** @engines: Engine set being iterated */
66 const struct i915_gem_engines *engines;
70 * enum i915_gem_engine_type - Describes the type of an i915_gem_proto_engine
72 enum i915_gem_engine_type {
73 /** @I915_GEM_ENGINE_TYPE_INVALID: An invalid engine */
74 I915_GEM_ENGINE_TYPE_INVALID = 0,
76 /** @I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine */
77 I915_GEM_ENGINE_TYPE_PHYSICAL,
79 /** @I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set */
80 I915_GEM_ENGINE_TYPE_BALANCED,
82 /** @I915_GEM_ENGINE_TYPE_PARALLEL: A parallel engine set */
83 I915_GEM_ENGINE_TYPE_PARALLEL,
87 * struct i915_gem_proto_engine - prototype engine
89 * This struct describes an engine that a context may contain. Engines
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.
98 * - I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine, described by
99 * i915_gem_proto_engine::engine.
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.
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.
108 struct i915_gem_proto_engine {
109 /** @type: Type of this engine */
110 enum i915_gem_engine_type type;
112 /** @engine: Engine, for physical */
113 struct intel_engine_cs *engine;
115 /** @num_siblings: Number of balanced or parallel siblings */
116 unsigned int num_siblings;
118 /** @width: Width of each sibling */
121 /** @siblings: Balanced siblings or num_siblings * width for parallel */
122 struct intel_engine_cs **siblings;
124 /** @sseu: Client-set SSEU parameters */
125 struct intel_sseu sseu;
129 * struct i915_gem_proto_context - prototype context
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.
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.
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.
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.
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:
166 * - Mesa/i965 didn't use the engines or VM APIs at all
168 * - Mesa/ANV used the engines API but via CONTEXT_CREATE_EXT_SETPARAM and
169 * didn't use the VM API.
171 * - Mesa/iris didn't use the engines or VM APIs at all
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.
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.
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.
190 struct i915_gem_proto_context {
191 /** @vm: See &i915_gem_context.vm */
192 struct i915_address_space *vm;
194 /** @user_flags: See &i915_gem_context.user_flags */
195 unsigned long user_flags;
197 /** @sched: See &i915_gem_context.sched */
198 struct i915_sched_attr sched;
200 /** @num_user_engines: Number of user-specified engines or -1 */
201 int num_user_engines;
203 /** @user_engines: User-specified engines */
204 struct i915_gem_proto_engine *user_engines;
206 /** @legacy_rcs_sseu: Client-set SSEU parameters for the legacy RCS */
207 struct intel_sseu legacy_rcs_sseu;
209 /** @single_timeline: See See &i915_gem_context.syncobj */
210 bool single_timeline;
212 /** @uses_protected_content: See &i915_gem_context.uses_protected_content */
213 bool uses_protected_content;
215 /** @pxp_wakeref: See &i915_gem_context.pxp_wakeref */
216 intel_wakeref_t pxp_wakeref;
220 * struct i915_gem_context - client state
222 * The struct i915_gem_context represents the combined view of the driver and
223 * logical hardware state for a particular client.
225 struct i915_gem_context {
226 /** @i915: i915 device backpointer */
227 struct drm_i915_private *i915;
229 /** @file_priv: owning file descriptor */
230 struct drm_i915_file_private *file_priv;
233 * @engines: User defined engines for this context
235 * Various uAPI offer the ability to lookup up an
236 * index from this array to select an engine operate on.
238 * Multiple logically distinct instances of the same engine
239 * may be defined in the array, as well as composite virtual
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.
250 * User defined by I915_CONTEXT_PARAM_ENGINE (when the
251 * CONTEXT_USER_ENGINES flag is set).
253 struct i915_gem_engines __rcu *engines;
255 /** @engines_mutex: guards writes to engines */
256 struct mutex engines_mutex;
259 * @syncobj: Shared timeline syncobj
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.
270 struct drm_syncobj *syncobj;
273 * @vm: unique address space (GTT)
275 * In full-ppgtt mode, each context has its own address space ensuring
276 * complete seperation of one client from all others.
278 * In other modes, this is a NULL pointer with the expectation that
279 * the caller uses the shared global GTT.
281 struct i915_address_space *vm;
284 * @pid: process id of creator
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.
293 /** @link: place with &drm_i915_private.context_list */
294 struct list_head link;
297 * @ref: reference count
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.
310 * Work item for deferred cleanup, since i915_gem_context_put() tends to
311 * be called from hardirq context.
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.
317 struct work_struct release_work;
320 * @rcu: rcu_head for deferred freeing.
325 * @user_flags: small set of booleans controlled by the user
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
334 * @flags: small set of booleans
337 #define CONTEXT_CLOSED 0
338 #define CONTEXT_USER_ENGINES 1
341 * @uses_protected_content: context uses PXP-encrypted objects.
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.
348 bool uses_protected_content;
351 * @pxp_wakeref: wakeref to keep the device awake when PXP is in use
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
360 intel_wakeref_t pxp_wakeref;
362 /** @mutex: guards everything that isn't engines or handles_vma */
365 /** @sched: scheduler parameters */
366 struct i915_sched_attr sched;
368 /** @guilty_count: How many times this context has caused a GPU hang. */
369 atomic_t guilty_count;
371 * @active_count: How many times this context was active during a GPU
372 * hang, but did not cause it.
374 atomic_t active_count;
377 * @hang_timestamp: The last time(s) this context caused a GPU hang
379 unsigned long hang_timestamp[2];
380 #define CONTEXT_FAST_HANG_JIFFIES (120 * HZ) /* 3 hangs within 120s? Banned! */
382 /** @remap_slice: Bitmask of cache lines that need remapping */
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)
390 struct radix_tree_root handles_vma;
392 /** @lut_mutex: Locks handles_vma */
393 struct mutex lut_mutex;
396 * @name: arbitrary name, used for user debug
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.
402 char name[TASK_COMM_LEN + 8];
404 /** @stale: tracks stale engines to be destroyed */
406 /** @lock: guards engines */
408 /** @engines: list of stale engines */
409 struct list_head engines;
413 #endif /* __I915_GEM_CONTEXT_TYPES_H__ */