diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_request.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_request.h | 721 |
1 files changed, 0 insertions, 721 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h deleted file mode 100644 index 0d6d39f19506..000000000000 --- a/drivers/gpu/drm/i915/i915_gem_request.h +++ /dev/null @@ -1,721 +0,0 @@ -/* - * Copyright © 2008-2015 Intel Corporation - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice (including the next - * paragraph) shall be included in all copies or substantial portions of the - * Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - * - */ - -#ifndef I915_GEM_REQUEST_H -#define I915_GEM_REQUEST_H - -#include <linux/dma-fence.h> - -#include "i915_gem.h" -#include "i915_sw_fence.h" - -#include <uapi/drm/i915_drm.h> - -struct drm_file; -struct drm_i915_gem_object; -struct drm_i915_gem_request; - -struct intel_wait { - struct rb_node node; - struct task_struct *tsk; - struct drm_i915_gem_request *request; - u32 seqno; -}; - -struct intel_signal_node { - struct rb_node node; - struct intel_wait wait; -}; - -struct i915_dependency { - struct i915_priotree *signaler; - struct list_head signal_link; - struct list_head wait_link; - struct list_head dfs_link; - unsigned long flags; -#define I915_DEPENDENCY_ALLOC BIT(0) -}; - -/* Requests exist in a complex web of interdependencies. Each request - * has to wait for some other request to complete before it is ready to be run - * (e.g. we have to wait until the pixels have been rendering into a texture - * before we can copy from it). We track the readiness of a request in terms - * of fences, but we also need to keep the dependency tree for the lifetime - * of the request (beyond the life of an individual fence). We use the tree - * at various points to reorder the requests whilst keeping the requests - * in order with respect to their various dependencies. - */ -struct i915_priotree { - struct list_head signalers_list; /* those before us, we depend upon */ - struct list_head waiters_list; /* those after us, they depend upon us */ - struct list_head link; - int priority; -}; - -enum { - I915_PRIORITY_MIN = I915_CONTEXT_MIN_USER_PRIORITY - 1, - I915_PRIORITY_NORMAL = I915_CONTEXT_DEFAULT_PRIORITY, - I915_PRIORITY_MAX = I915_CONTEXT_MAX_USER_PRIORITY + 1, - - I915_PRIORITY_INVALID = INT_MIN -}; - -struct i915_gem_capture_list { - struct i915_gem_capture_list *next; - struct i915_vma *vma; -}; - -/** - * Request queue structure. - * - * The request queue allows us to note sequence numbers that have been emitted - * and may be associated with active buffers to be retired. - * - * By keeping this list, we can avoid having to do questionable sequence - * number comparisons on buffer last_read|write_seqno. It also allows an - * emission time to be associated with the request for tracking how far ahead - * of the GPU the submission is. - * - * When modifying this structure be very aware that we perform a lockless - * RCU lookup of it that may race against reallocation of the struct - * from the slab freelist. We intentionally do not zero the structure on - * allocation so that the lookup can use the dangling pointers (and is - * cogniscent that those pointers may be wrong). Instead, everything that - * needs to be initialised must be done so explicitly. - * - * The requests are reference counted. - */ -struct drm_i915_gem_request { - struct dma_fence fence; - spinlock_t lock; - - /** On Which ring this request was generated */ - struct drm_i915_private *i915; - - /** - * Context and ring buffer related to this request - * Contexts are refcounted, so when this request is associated with a - * context, we must increment the context's refcount, to guarantee that - * it persists while any request is linked to it. Requests themselves - * are also refcounted, so the request will only be freed when the last - * reference to it is dismissed, and the code in - * i915_gem_request_free() will then decrement the refcount on the - * context. - */ - struct i915_gem_context *ctx; - struct intel_engine_cs *engine; - struct intel_ring *ring; - struct intel_timeline *timeline; - struct intel_signal_node signaling; - - /* Fences for the various phases in the request's lifetime. - * - * The submit fence is used to await upon all of the request's - * dependencies. When it is signaled, the request is ready to run. - * It is used by the driver to then queue the request for execution. - */ - struct i915_sw_fence submit; - wait_queue_entry_t submitq; - wait_queue_head_t execute; - - /* A list of everyone we wait upon, and everyone who waits upon us. - * Even though we will not be submitted to the hardware before the - * submit fence is signaled (it waits for all external events as well - * as our own requests), the scheduler still needs to know the - * dependency tree for the lifetime of the request (from execbuf - * to retirement), i.e. bidirectional dependency information for the - * request not tied to individual fences. - */ - struct i915_priotree priotree; - struct i915_dependency dep; - - /** GEM sequence number associated with this request on the - * global execution timeline. It is zero when the request is not - * on the HW queue (i.e. not on the engine timeline list). - * Its value is guarded by the timeline spinlock. - */ - u32 global_seqno; - - /** Position in the ring of the start of the request */ - u32 head; - - /** - * Position in the ring of the start of the postfix. - * This is required to calculate the maximum available ring space - * without overwriting the postfix. - */ - u32 postfix; - - /** Position in the ring of the end of the whole request */ - u32 tail; - - /** Position in the ring of the end of any workarounds after the tail */ - u32 wa_tail; - - /** Preallocate space in the ring for the emitting the request */ - u32 reserved_space; - - /** Batch buffer related to this request if any (used for - * error state dump only). - */ - struct i915_vma *batch; - /** Additional buffers requested by userspace to be captured upon - * a GPU hang. The vma/obj on this list are protected by their - * active reference - all objects on this list must also be - * on the active_list (of their final request). - */ - struct i915_gem_capture_list *capture_list; - struct list_head active_list; - - /** Time at which this request was emitted, in jiffies. */ - unsigned long emitted_jiffies; - - bool waitboost; - - /** engine->request_list entry for this request */ - struct list_head link; - - /** ring->request_list entry for this request */ - struct list_head ring_link; - - struct drm_i915_file_private *file_priv; - /** file_priv list entry for this request */ - struct list_head client_link; -}; - -#define I915_FENCE_GFP (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN) - -extern const struct dma_fence_ops i915_fence_ops; - -static inline bool dma_fence_is_i915(const struct dma_fence *fence) -{ - return fence->ops == &i915_fence_ops; -} - -struct drm_i915_gem_request * __must_check -i915_gem_request_alloc(struct intel_engine_cs *engine, - struct i915_gem_context *ctx); -void i915_gem_request_retire_upto(struct drm_i915_gem_request *req); - -static inline struct drm_i915_gem_request * -to_request(struct dma_fence *fence) -{ - /* We assume that NULL fence/request are interoperable */ - BUILD_BUG_ON(offsetof(struct drm_i915_gem_request, fence) != 0); - GEM_BUG_ON(fence && !dma_fence_is_i915(fence)); - return container_of(fence, struct drm_i915_gem_request, fence); -} - -static inline struct drm_i915_gem_request * -i915_gem_request_get(struct drm_i915_gem_request *req) -{ - return to_request(dma_fence_get(&req->fence)); -} - -static inline struct drm_i915_gem_request * -i915_gem_request_get_rcu(struct drm_i915_gem_request *req) -{ - return to_request(dma_fence_get_rcu(&req->fence)); -} - -static inline void -i915_gem_request_put(struct drm_i915_gem_request *req) -{ - dma_fence_put(&req->fence); -} - -static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst, - struct drm_i915_gem_request *src) -{ - if (src) - i915_gem_request_get(src); - - if (*pdst) - i915_gem_request_put(*pdst); - - *pdst = src; -} - -/** - * i915_gem_request_global_seqno - report the current global seqno - * @request - the request - * - * A request is assigned a global seqno only when it is on the hardware - * execution queue. The global seqno can be used to maintain a list of - * requests on the same engine in retirement order, for example for - * constructing a priority queue for waiting. Prior to its execution, or - * if it is subsequently removed in the event of preemption, its global - * seqno is zero. As both insertion and removal from the execution queue - * may operate in IRQ context, it is not guarded by the usual struct_mutex - * BKL. Instead those relying on the global seqno must be prepared for its - * value to change between reads. Only when the request is complete can - * the global seqno be stable (due to the memory barriers on submitting - * the commands to the hardware to write the breadcrumb, if the HWS shows - * that it has passed the global seqno and the global seqno is unchanged - * after the read, it is indeed complete). - */ -static u32 -i915_gem_request_global_seqno(const struct drm_i915_gem_request *request) -{ - return READ_ONCE(request->global_seqno); -} - -int -i915_gem_request_await_object(struct drm_i915_gem_request *to, - struct drm_i915_gem_object *obj, - bool write); -int i915_gem_request_await_dma_fence(struct drm_i915_gem_request *req, - struct dma_fence *fence); - -void __i915_add_request(struct drm_i915_gem_request *req, bool flush_caches); -#define i915_add_request(req) \ - __i915_add_request(req, false) - -void __i915_gem_request_submit(struct drm_i915_gem_request *request); -void i915_gem_request_submit(struct drm_i915_gem_request *request); - -void __i915_gem_request_unsubmit(struct drm_i915_gem_request *request); -void i915_gem_request_unsubmit(struct drm_i915_gem_request *request); - -struct intel_rps_client; -#define NO_WAITBOOST ERR_PTR(-1) -#define IS_RPS_CLIENT(p) (!IS_ERR(p)) -#define IS_RPS_USER(p) (!IS_ERR_OR_NULL(p)) - -long i915_wait_request(struct drm_i915_gem_request *req, - unsigned int flags, - long timeout) - __attribute__((nonnull(1))); -#define I915_WAIT_INTERRUPTIBLE BIT(0) -#define I915_WAIT_LOCKED BIT(1) /* struct_mutex held, handle GPU reset */ -#define I915_WAIT_ALL BIT(2) /* used by i915_gem_object_wait() */ - -static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine); - -/** - * Returns true if seq1 is later than seq2. - */ -static inline bool i915_seqno_passed(u32 seq1, u32 seq2) -{ - return (s32)(seq1 - seq2) >= 0; -} - -static inline bool -__i915_gem_request_completed(const struct drm_i915_gem_request *req, u32 seqno) -{ - GEM_BUG_ON(!seqno); - return i915_seqno_passed(intel_engine_get_seqno(req->engine), seqno) && - seqno == i915_gem_request_global_seqno(req); -} - -static inline bool -i915_gem_request_completed(const struct drm_i915_gem_request *req) -{ - u32 seqno; - - seqno = i915_gem_request_global_seqno(req); - if (!seqno) - return false; - - return __i915_gem_request_completed(req, seqno); -} - -/* We treat requests as fences. This is not be to confused with our - * "fence registers" but pipeline synchronisation objects ala GL_ARB_sync. - * We use the fences to synchronize access from the CPU with activity on the - * GPU, for example, we should not rewrite an object's PTE whilst the GPU - * is reading them. We also track fences at a higher level to provide - * implicit synchronisation around GEM objects, e.g. set-domain will wait - * for outstanding GPU rendering before marking the object ready for CPU - * access, or a pageflip will wait until the GPU is complete before showing - * the frame on the scanout. - * - * In order to use a fence, the object must track the fence it needs to - * serialise with. For example, GEM objects want to track both read and - * write access so that we can perform concurrent read operations between - * the CPU and GPU engines, as well as waiting for all rendering to - * complete, or waiting for the last GPU user of a "fence register". The - * object then embeds a #i915_gem_active to track the most recent (in - * retirement order) request relevant for the desired mode of access. - * The #i915_gem_active is updated with i915_gem_active_set() to track the - * most recent fence request, typically this is done as part of - * i915_vma_move_to_active(). - * - * When the #i915_gem_active completes (is retired), it will - * signal its completion to the owner through a callback as well as mark - * itself as idle (i915_gem_active.request == NULL). The owner - * can then perform any action, such as delayed freeing of an active - * resource including itself. - */ -struct i915_gem_active; - -typedef void (*i915_gem_retire_fn)(struct i915_gem_active *, - struct drm_i915_gem_request *); - -struct i915_gem_active { - struct drm_i915_gem_request __rcu *request; - struct list_head link; - i915_gem_retire_fn retire; -}; - -void i915_gem_retire_noop(struct i915_gem_active *, - struct drm_i915_gem_request *request); - -/** - * init_request_active - prepares the activity tracker for use - * @active - the active tracker - * @func - a callback when then the tracker is retired (becomes idle), - * can be NULL - * - * init_request_active() prepares the embedded @active struct for use as - * an activity tracker, that is for tracking the last known active request - * associated with it. When the last request becomes idle, when it is retired - * after completion, the optional callback @func is invoked. - */ -static inline void -init_request_active(struct i915_gem_active *active, - i915_gem_retire_fn retire) -{ - INIT_LIST_HEAD(&active->link); - active->retire = retire ?: i915_gem_retire_noop; -} - -/** - * i915_gem_active_set - updates the tracker to watch the current request - * @active - the active tracker - * @request - the request to watch - * - * i915_gem_active_set() watches the given @request for completion. Whilst - * that @request is busy, the @active reports busy. When that @request is - * retired, the @active tracker is updated to report idle. - */ -static inline void -i915_gem_active_set(struct i915_gem_active *active, - struct drm_i915_gem_request *request) -{ - list_move(&active->link, &request->active_list); - rcu_assign_pointer(active->request, request); -} - -/** - * i915_gem_active_set_retire_fn - updates the retirement callback - * @active - the active tracker - * @fn - the routine called when the request is retired - * @mutex - struct_mutex used to guard retirements - * - * i915_gem_active_set_retire_fn() updates the function pointer that - * is called when the final request associated with the @active tracker - * is retired. - */ -static inline void -i915_gem_active_set_retire_fn(struct i915_gem_active *active, - i915_gem_retire_fn fn, - struct mutex *mutex) -{ - lockdep_assert_held(mutex); - active->retire = fn ?: i915_gem_retire_noop; -} - -static inline struct drm_i915_gem_request * -__i915_gem_active_peek(const struct i915_gem_active *active) -{ - /* Inside the error capture (running with the driver in an unknown - * state), we want to bend the rules slightly (a lot). - * - * Work is in progress to make it safer, in the meantime this keeps - * the known issue from spamming the logs. - */ - return rcu_dereference_protected(active->request, 1); -} - -/** - * i915_gem_active_raw - return the active request - * @active - the active tracker - * - * i915_gem_active_raw() returns the current request being tracked, or NULL. - * It does not obtain a reference on the request for the caller, so the caller - * must hold struct_mutex. - */ -static inline struct drm_i915_gem_request * -i915_gem_active_raw(const struct i915_gem_active *active, struct mutex *mutex) -{ - return rcu_dereference_protected(active->request, - lockdep_is_held(mutex)); -} - -/** - * i915_gem_active_peek - report the active request being monitored - * @active - the active tracker - * - * i915_gem_active_peek() returns the current request being tracked if - * still active, or NULL. It does not obtain a reference on the request - * for the caller, so the caller must hold struct_mutex. - */ -static inline struct drm_i915_gem_request * -i915_gem_active_peek(const struct i915_gem_active *active, struct mutex *mutex) -{ - struct drm_i915_gem_request *request; - - request = i915_gem_active_raw(active, mutex); - if (!request || i915_gem_request_completed(request)) - return NULL; - - return request; -} - -/** - * i915_gem_active_get - return a reference to the active request - * @active - the active tracker - * - * i915_gem_active_get() returns a reference to the active request, or NULL - * if the active tracker is idle. The caller must hold struct_mutex. - */ -static inline struct drm_i915_gem_request * -i915_gem_active_get(const struct i915_gem_active *active, struct mutex *mutex) -{ - return i915_gem_request_get(i915_gem_active_peek(active, mutex)); -} - -/** - * __i915_gem_active_get_rcu - return a reference to the active request - * @active - the active tracker - * - * __i915_gem_active_get() returns a reference to the active request, or NULL - * if the active tracker is idle. The caller must hold the RCU read lock, but - * the returned pointer is safe to use outside of RCU. - */ -static inline struct drm_i915_gem_request * -__i915_gem_active_get_rcu(const struct i915_gem_active *active) -{ - /* Performing a lockless retrieval of the active request is super - * tricky. SLAB_TYPESAFE_BY_RCU merely guarantees that the backing - * slab of request objects will not be freed whilst we hold the - * RCU read lock. It does not guarantee that the request itself - * will not be freed and then *reused*. Viz, - * - * Thread A Thread B - * - * req = active.request - * retire(req) -> free(req); - * (req is now first on the slab freelist) - * active.request = NULL - * - * req = new submission on a new object - * ref(req) - * - * To prevent the request from being reused whilst the caller - * uses it, we take a reference like normal. Whilst acquiring - * the reference we check that it is not in a destroyed state - * (refcnt == 0). That prevents the request being reallocated - * whilst the caller holds on to it. To check that the request - * was not reallocated as we acquired the reference we have to - * check that our request remains the active request across - * the lookup, in the same manner as a seqlock. The visibility - * of the pointer versus the reference counting is controlled - * by using RCU barriers (rcu_dereference and rcu_assign_pointer). - * - * In the middle of all that, we inspect whether the request is - * complete. Retiring is lazy so the request may be completed long - * before the active tracker is updated. Querying whether the - * request is complete is far cheaper (as it involves no locked - * instructions setting cachelines to exclusive) than acquiring - * the reference, so we do it first. The RCU read lock ensures the - * pointer dereference is valid, but does not ensure that the - * seqno nor HWS is the right one! However, if the request was - * reallocated, that means the active tracker's request was complete. - * If the new request is also complete, then both are and we can - * just report the active tracker is idle. If the new request is - * incomplete, then we acquire a reference on it and check that - * it remained the active request. - * - * It is then imperative that we do not zero the request on - * reallocation, so that we can chase the dangling pointers! - * See i915_gem_request_alloc(). - */ - do { - struct drm_i915_gem_request *request; - - request = rcu_dereference(active->request); - if (!request || i915_gem_request_completed(request)) - return NULL; - - /* An especially silly compiler could decide to recompute the - * result of i915_gem_request_completed, more specifically - * re-emit the load for request->fence.seqno. A race would catch - * a later seqno value, which could flip the result from true to - * false. Which means part of the instructions below might not - * be executed, while later on instructions are executed. Due to - * barriers within the refcounting the inconsistency can't reach - * past the call to i915_gem_request_get_rcu, but not executing - * that while still executing i915_gem_request_put() creates - * havoc enough. Prevent this with a compiler barrier. - */ - barrier(); - - request = i915_gem_request_get_rcu(request); - - /* What stops the following rcu_access_pointer() from occurring - * before the above i915_gem_request_get_rcu()? If we were - * to read the value before pausing to get the reference to - * the request, we may not notice a change in the active - * tracker. - * - * The rcu_access_pointer() is a mere compiler barrier, which - * means both the CPU and compiler are free to perform the - * memory read without constraint. The compiler only has to - * ensure that any operations after the rcu_access_pointer() - * occur afterwards in program order. This means the read may - * be performed earlier by an out-of-order CPU, or adventurous - * compiler. - * - * The atomic operation at the heart of - * i915_gem_request_get_rcu(), see dma_fence_get_rcu(), is - * atomic_inc_not_zero() which is only a full memory barrier - * when successful. That is, if i915_gem_request_get_rcu() - * returns the request (and so with the reference counted - * incremented) then the following read for rcu_access_pointer() - * must occur after the atomic operation and so confirm - * that this request is the one currently being tracked. - * - * The corresponding write barrier is part of - * rcu_assign_pointer(). - */ - if (!request || request == rcu_access_pointer(active->request)) - return rcu_pointer_handoff(request); - - i915_gem_request_put(request); - } while (1); -} - -/** - * i915_gem_active_get_unlocked - return a reference to the active request - * @active - the active tracker - * - * i915_gem_active_get_unlocked() returns a reference to the active request, - * or NULL if the active tracker is idle. The reference is obtained under RCU, - * so no locking is required by the caller. - * - * The reference should be freed with i915_gem_request_put(). - */ -static inline struct drm_i915_gem_request * -i915_gem_active_get_unlocked(const struct i915_gem_active *active) -{ - struct drm_i915_gem_request *request; - - rcu_read_lock(); - request = __i915_gem_active_get_rcu(active); - rcu_read_unlock(); - - return request; -} - -/** - * i915_gem_active_isset - report whether the active tracker is assigned - * @active - the active tracker - * - * i915_gem_active_isset() returns true if the active tracker is currently - * assigned to a request. Due to the lazy retiring, that request may be idle - * and this may report stale information. - */ -static inline bool -i915_gem_active_isset(const struct i915_gem_active *active) -{ - return rcu_access_pointer(active->request); -} - -/** - * i915_gem_active_wait - waits until the request is completed - * @active - the active request on which to wait - * @flags - how to wait - * @timeout - how long to wait at most - * @rps - userspace client to charge for a waitboost - * - * i915_gem_active_wait() waits until the request is completed before - * returning, without requiring any locks to be held. Note that it does not - * retire any requests before returning. - * - * This function relies on RCU in order to acquire the reference to the active - * request without holding any locks. See __i915_gem_active_get_rcu() for the - * glory details on how that is managed. Once the reference is acquired, we - * can then wait upon the request, and afterwards release our reference, - * free of any locking. - * - * This function wraps i915_wait_request(), see it for the full details on - * the arguments. - * - * Returns 0 if successful, or a negative error code. - */ -static inline int -i915_gem_active_wait(const struct i915_gem_active *active, unsigned int flags) -{ - struct drm_i915_gem_request *request; - long ret = 0; - - request = i915_gem_active_get_unlocked(active); - if (request) { - ret = i915_wait_request(request, flags, MAX_SCHEDULE_TIMEOUT); - i915_gem_request_put(request); - } - - return ret < 0 ? ret : 0; -} - -/** - * i915_gem_active_retire - waits until the request is retired - * @active - the active request on which to wait - * - * i915_gem_active_retire() waits until the request is completed, - * and then ensures that at least the retirement handler for this - * @active tracker is called before returning. If the @active - * tracker is idle, the function returns immediately. - */ -static inline int __must_check -i915_gem_active_retire(struct i915_gem_active *active, - struct mutex *mutex) -{ - struct drm_i915_gem_request *request; - long ret; - - request = i915_gem_active_raw(active, mutex); - if (!request) - return 0; - - ret = i915_wait_request(request, - I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED, - MAX_SCHEDULE_TIMEOUT); - if (ret < 0) - return ret; - - list_del_init(&active->link); - RCU_INIT_POINTER(active->request, NULL); - - active->retire(active, request); - - return 0; -} - -#define for_each_active(mask, idx) \ - for (; mask ? idx = ffs(mask) - 1, 1 : 0; mask &= ~BIT(idx)) - -#endif /* I915_GEM_REQUEST_H */ |
