c3b147604f
We use some of the lower bits of the retire function pointer for potential flags, which is quite thorny, since the caller needs to remember to give the function the correct alignment with __i915_active_call, otherwise we might incorrectly unpack the pointer and jump to some garbage address later. Instead of all this let's just pass the flags along as a separate parameter. Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Suggested-by: Daniel Vetter <daniel@ffwll.ch> References:ca419f407b
("drm/i915: Fix crash in auto_retire") References:d8e44e4dd2
("drm/i915/overlay: Fix active retire callback alignment") References:fd5f262db1
("drm/i915/selftests: Fix active retire callback alignment") Signed-off-by: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210504164136.96456-1-matthew.auld@intel.com
505 lines
11 KiB
C
505 lines
11 KiB
C
// SPDX-License-Identifier: MIT
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/*
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* Copyright © 2019 Intel Corporation
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*/
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#include "gem/i915_gem_context.h"
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#include "gem/i915_gem_pm.h"
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#include "i915_drv.h"
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#include "i915_globals.h"
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#include "intel_context.h"
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#include "intel_engine.h"
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#include "intel_engine_pm.h"
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#include "intel_ring.h"
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static struct i915_global_context {
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struct i915_global base;
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struct kmem_cache *slab_ce;
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} global;
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static struct intel_context *intel_context_alloc(void)
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{
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return kmem_cache_zalloc(global.slab_ce, GFP_KERNEL);
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}
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static void rcu_context_free(struct rcu_head *rcu)
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{
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struct intel_context *ce = container_of(rcu, typeof(*ce), rcu);
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kmem_cache_free(global.slab_ce, ce);
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}
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void intel_context_free(struct intel_context *ce)
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{
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call_rcu(&ce->rcu, rcu_context_free);
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}
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struct intel_context *
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intel_context_create(struct intel_engine_cs *engine)
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{
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struct intel_context *ce;
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ce = intel_context_alloc();
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if (!ce)
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return ERR_PTR(-ENOMEM);
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intel_context_init(ce, engine);
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return ce;
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}
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int intel_context_alloc_state(struct intel_context *ce)
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{
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int err = 0;
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if (mutex_lock_interruptible(&ce->pin_mutex))
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return -EINTR;
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if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
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if (intel_context_is_banned(ce)) {
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err = -EIO;
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goto unlock;
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}
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err = ce->ops->alloc(ce);
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if (unlikely(err))
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goto unlock;
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set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
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}
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unlock:
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mutex_unlock(&ce->pin_mutex);
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return err;
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}
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static int intel_context_active_acquire(struct intel_context *ce)
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{
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int err;
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__i915_active_acquire(&ce->active);
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if (intel_context_is_barrier(ce))
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return 0;
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/* Preallocate tracking nodes */
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err = i915_active_acquire_preallocate_barrier(&ce->active,
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ce->engine);
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if (err)
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i915_active_release(&ce->active);
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return err;
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}
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static void intel_context_active_release(struct intel_context *ce)
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{
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/* Nodes preallocated in intel_context_active() */
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i915_active_acquire_barrier(&ce->active);
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i915_active_release(&ce->active);
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}
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static int __context_pin_state(struct i915_vma *vma, struct i915_gem_ww_ctx *ww)
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{
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unsigned int bias = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;
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int err;
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err = i915_ggtt_pin(vma, ww, 0, bias | PIN_HIGH);
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if (err)
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return err;
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err = i915_active_acquire(&vma->active);
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if (err)
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goto err_unpin;
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/*
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* And mark it as a globally pinned object to let the shrinker know
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* it cannot reclaim the object until we release it.
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*/
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i915_vma_make_unshrinkable(vma);
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vma->obj->mm.dirty = true;
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return 0;
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err_unpin:
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i915_vma_unpin(vma);
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return err;
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}
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static void __context_unpin_state(struct i915_vma *vma)
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{
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i915_vma_make_shrinkable(vma);
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i915_active_release(&vma->active);
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__i915_vma_unpin(vma);
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}
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static int __ring_active(struct intel_ring *ring,
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struct i915_gem_ww_ctx *ww)
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{
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int err;
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err = intel_ring_pin(ring, ww);
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if (err)
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return err;
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err = i915_active_acquire(&ring->vma->active);
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if (err)
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goto err_pin;
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return 0;
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err_pin:
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intel_ring_unpin(ring);
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return err;
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}
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static void __ring_retire(struct intel_ring *ring)
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{
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i915_active_release(&ring->vma->active);
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intel_ring_unpin(ring);
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}
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static int intel_context_pre_pin(struct intel_context *ce,
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struct i915_gem_ww_ctx *ww)
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{
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int err;
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CE_TRACE(ce, "active\n");
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err = __ring_active(ce->ring, ww);
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if (err)
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return err;
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err = intel_timeline_pin(ce->timeline, ww);
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if (err)
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goto err_ring;
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if (!ce->state)
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return 0;
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err = __context_pin_state(ce->state, ww);
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if (err)
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goto err_timeline;
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return 0;
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err_timeline:
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intel_timeline_unpin(ce->timeline);
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err_ring:
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__ring_retire(ce->ring);
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return err;
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}
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static void intel_context_post_unpin(struct intel_context *ce)
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{
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if (ce->state)
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__context_unpin_state(ce->state);
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intel_timeline_unpin(ce->timeline);
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__ring_retire(ce->ring);
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}
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int __intel_context_do_pin_ww(struct intel_context *ce,
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struct i915_gem_ww_ctx *ww)
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{
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bool handoff = false;
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void *vaddr;
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int err = 0;
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if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
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err = intel_context_alloc_state(ce);
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if (err)
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return err;
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}
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/*
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* We always pin the context/ring/timeline here, to ensure a pin
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* refcount for __intel_context_active(), which prevent a lock
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* inversion of ce->pin_mutex vs dma_resv_lock().
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*/
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err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, ww);
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if (!err && ce->ring->vma->obj)
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err = i915_gem_object_lock(ce->ring->vma->obj, ww);
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if (!err && ce->state)
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err = i915_gem_object_lock(ce->state->obj, ww);
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if (!err)
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err = intel_context_pre_pin(ce, ww);
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if (err)
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return err;
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err = i915_active_acquire(&ce->active);
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if (err)
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goto err_ctx_unpin;
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err = ce->ops->pre_pin(ce, ww, &vaddr);
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if (err)
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goto err_release;
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err = mutex_lock_interruptible(&ce->pin_mutex);
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if (err)
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goto err_post_unpin;
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if (unlikely(intel_context_is_closed(ce))) {
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err = -ENOENT;
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goto err_unlock;
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}
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if (likely(!atomic_add_unless(&ce->pin_count, 1, 0))) {
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err = intel_context_active_acquire(ce);
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if (unlikely(err))
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goto err_unlock;
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err = ce->ops->pin(ce, vaddr);
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if (err) {
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intel_context_active_release(ce);
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goto err_unlock;
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}
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CE_TRACE(ce, "pin ring:{start:%08x, head:%04x, tail:%04x}\n",
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i915_ggtt_offset(ce->ring->vma),
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ce->ring->head, ce->ring->tail);
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handoff = true;
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smp_mb__before_atomic(); /* flush pin before it is visible */
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atomic_inc(&ce->pin_count);
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}
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GEM_BUG_ON(!intel_context_is_pinned(ce)); /* no overflow! */
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err_unlock:
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mutex_unlock(&ce->pin_mutex);
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err_post_unpin:
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if (!handoff)
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ce->ops->post_unpin(ce);
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err_release:
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i915_active_release(&ce->active);
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err_ctx_unpin:
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intel_context_post_unpin(ce);
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/*
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* Unlock the hwsp_ggtt object since it's shared.
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* In principle we can unlock all the global state locked above
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* since it's pinned and doesn't need fencing, and will
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* thus remain resident until it is explicitly unpinned.
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*/
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i915_gem_ww_unlock_single(ce->timeline->hwsp_ggtt->obj);
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return err;
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}
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int __intel_context_do_pin(struct intel_context *ce)
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{
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struct i915_gem_ww_ctx ww;
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int err;
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i915_gem_ww_ctx_init(&ww, true);
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retry:
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err = __intel_context_do_pin_ww(ce, &ww);
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if (err == -EDEADLK) {
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err = i915_gem_ww_ctx_backoff(&ww);
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if (!err)
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goto retry;
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}
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i915_gem_ww_ctx_fini(&ww);
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return err;
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}
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void intel_context_unpin(struct intel_context *ce)
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{
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if (!atomic_dec_and_test(&ce->pin_count))
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return;
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CE_TRACE(ce, "unpin\n");
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ce->ops->unpin(ce);
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ce->ops->post_unpin(ce);
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/*
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* Once released, we may asynchronously drop the active reference.
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* As that may be the only reference keeping the context alive,
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* take an extra now so that it is not freed before we finish
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* dereferencing it.
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*/
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intel_context_get(ce);
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intel_context_active_release(ce);
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intel_context_put(ce);
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}
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static void __intel_context_retire(struct i915_active *active)
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{
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struct intel_context *ce = container_of(active, typeof(*ce), active);
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CE_TRACE(ce, "retire runtime: { total:%lluns, avg:%lluns }\n",
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intel_context_get_total_runtime_ns(ce),
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intel_context_get_avg_runtime_ns(ce));
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set_bit(CONTEXT_VALID_BIT, &ce->flags);
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intel_context_post_unpin(ce);
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intel_context_put(ce);
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}
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static int __intel_context_active(struct i915_active *active)
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{
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struct intel_context *ce = container_of(active, typeof(*ce), active);
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intel_context_get(ce);
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/* everything should already be activated by intel_context_pre_pin() */
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GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->ring->vma->active));
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__intel_ring_pin(ce->ring);
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__intel_timeline_pin(ce->timeline);
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if (ce->state) {
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GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->state->active));
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__i915_vma_pin(ce->state);
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i915_vma_make_unshrinkable(ce->state);
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}
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return 0;
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}
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void
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intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
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{
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GEM_BUG_ON(!engine->cops);
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GEM_BUG_ON(!engine->gt->vm);
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kref_init(&ce->ref);
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ce->engine = engine;
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ce->ops = engine->cops;
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ce->sseu = engine->sseu;
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ce->ring = __intel_context_ring_size(SZ_4K);
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ewma_runtime_init(&ce->runtime.avg);
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ce->vm = i915_vm_get(engine->gt->vm);
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/* NB ce->signal_link/lock is used under RCU */
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spin_lock_init(&ce->signal_lock);
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INIT_LIST_HEAD(&ce->signals);
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mutex_init(&ce->pin_mutex);
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i915_active_init(&ce->active,
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__intel_context_active, __intel_context_retire, 0);
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}
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void intel_context_fini(struct intel_context *ce)
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{
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if (ce->timeline)
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intel_timeline_put(ce->timeline);
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i915_vm_put(ce->vm);
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mutex_destroy(&ce->pin_mutex);
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i915_active_fini(&ce->active);
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}
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static void i915_global_context_shrink(void)
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{
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kmem_cache_shrink(global.slab_ce);
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}
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static void i915_global_context_exit(void)
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{
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kmem_cache_destroy(global.slab_ce);
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}
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static struct i915_global_context global = { {
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.shrink = i915_global_context_shrink,
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.exit = i915_global_context_exit,
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} };
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int __init i915_global_context_init(void)
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{
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global.slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
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if (!global.slab_ce)
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return -ENOMEM;
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i915_global_register(&global.base);
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return 0;
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}
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void intel_context_enter_engine(struct intel_context *ce)
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{
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intel_engine_pm_get(ce->engine);
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intel_timeline_enter(ce->timeline);
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}
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void intel_context_exit_engine(struct intel_context *ce)
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{
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intel_timeline_exit(ce->timeline);
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intel_engine_pm_put(ce->engine);
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}
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int intel_context_prepare_remote_request(struct intel_context *ce,
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struct i915_request *rq)
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{
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struct intel_timeline *tl = ce->timeline;
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int err;
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/* Only suitable for use in remotely modifying this context */
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GEM_BUG_ON(rq->context == ce);
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if (rcu_access_pointer(rq->timeline) != tl) { /* timeline sharing! */
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/* Queue this switch after current activity by this context. */
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err = i915_active_fence_set(&tl->last_request, rq);
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if (err)
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return err;
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}
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/*
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* Guarantee context image and the timeline remains pinned until the
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* modifying request is retired by setting the ce activity tracker.
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*
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* But we only need to take one pin on the account of it. Or in other
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* words transfer the pinned ce object to tracked active request.
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*/
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GEM_BUG_ON(i915_active_is_idle(&ce->active));
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return i915_active_add_request(&ce->active, rq);
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}
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struct i915_request *intel_context_create_request(struct intel_context *ce)
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{
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struct i915_gem_ww_ctx ww;
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struct i915_request *rq;
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int err;
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i915_gem_ww_ctx_init(&ww, true);
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retry:
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err = intel_context_pin_ww(ce, &ww);
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if (!err) {
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rq = i915_request_create(ce);
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intel_context_unpin(ce);
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} else if (err == -EDEADLK) {
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err = i915_gem_ww_ctx_backoff(&ww);
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if (!err)
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goto retry;
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rq = ERR_PTR(err);
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} else {
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rq = ERR_PTR(err);
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}
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i915_gem_ww_ctx_fini(&ww);
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if (IS_ERR(rq))
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return rq;
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/*
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* timeline->mutex should be the inner lock, but is used as outer lock.
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* Hack around this to shut up lockdep in selftests..
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*/
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lockdep_unpin_lock(&ce->timeline->mutex, rq->cookie);
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mutex_release(&ce->timeline->mutex.dep_map, _RET_IP_);
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mutex_acquire(&ce->timeline->mutex.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
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rq->cookie = lockdep_pin_lock(&ce->timeline->mutex);
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return rq;
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}
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#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
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#include "selftest_context.c"
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#endif
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