If we want to percolate information back from the HW, up through the GEM context, we need to wait until the intel_context is scheduled out for the last time. This is handled by the retirement of the intel_context's barrier, i.e. by listening to the pulse after the notional unpin. So wait until the intel_context is finally retired before releasing the engine, so that we can inspect the final context state and pass it on.
Signed-off-by: Chris Wilson <[email protected]> Cc: Tvrtko Ursulin <[email protected]> --- drivers/gpu/drm/i915/gem/i915_gem_context.c | 16 +++--- drivers/gpu/drm/i915/i915_active.c | 57 ++++++++++++++++++++- drivers/gpu/drm/i915/i915_active.h | 3 +- 3 files changed, 64 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c index dffe0daee0d2..55f7879f6db4 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c @@ -570,23 +570,19 @@ static void engines_idle_release(struct i915_gem_context *ctx, engines->ctx = i915_gem_context_get(ctx); for_each_gem_engine(ce, engines, it) { - struct dma_fence *fence; - int err = 0; + int err; /* serialises with execbuf */ set_bit(CONTEXT_CLOSED_BIT, &ce->flags); if (!intel_context_pin_if_active(ce)) continue; - fence = i915_active_fence_get(&ce->timeline->last_request); - if (fence) { - err = i915_sw_fence_await_dma_fence(&engines->fence, - fence, 0, - GFP_KERNEL); - dma_fence_put(fence); - } + /* Wait until context is finally scheduled out and retired */ + err = i915_sw_fence_await_active(&engines->fence, + &ce->active, + I915_ACTIVE_AWAIT_BARRIER); intel_context_unpin(ce); - if (err < 0) + if (err) goto kill; } diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c index 7b685032cc1e..c01bf25c8e5e 100644 --- a/drivers/gpu/drm/i915/i915_active.c +++ b/drivers/gpu/drm/i915/i915_active.c @@ -542,6 +542,54 @@ static int __await_active(struct i915_active_fence *active, return 0; } +struct wait_barrier { + struct wait_queue_entry base; + struct i915_active *ref; +}; + +static int +barrier_wake(wait_queue_entry_t *wq, unsigned mode, int flags, void *key) +{ + struct wait_barrier *wb = container_of(wq, typeof(*wb), base); + + if (i915_active_is_idle(wb->ref)) { /* shared waitqueue, must check! */ + list_del(&wq->entry); + i915_sw_fence_complete(wq->private); + kfree(wq); + } + + return 0; +} + +static int __await_barrier(struct i915_active *ref, struct i915_sw_fence *fence) +{ + struct wait_barrier *wb; + + wb = kmalloc(sizeof(*wb), GFP_NOWAIT | __GFP_NOWARN); + if (unlikely(!wb)) + return -ENOMEM; + + if (!i915_active_acquire_if_busy(ref)) { + kfree(wb); + return 0; + } + + if (!i915_sw_fence_await(fence)) { + kfree(wb); + i915_active_release(ref); + return -EINVAL; + } + + wb->base.flags = 0; + wb->base.func = barrier_wake; + wb->base.private = fence; + + add_wait_queue(__var_waitqueue(ref), &wb->base); + + i915_active_release(ref); + return 0; +} + static int await_active(struct i915_active *ref, unsigned int flags, int (*fn)(void *arg, struct dma_fence *fence), @@ -556,7 +604,8 @@ static int await_active(struct i915_active *ref, return err; } - if (flags & I915_ACTIVE_AWAIT_ALL && i915_active_acquire_if_busy(ref)) { + if (flags & I915_ACTIVE_AWAIT_ACTIVE && + i915_active_acquire_if_busy(ref)) { struct active_node *it, *n; rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) { @@ -569,6 +618,12 @@ static int await_active(struct i915_active *ref, return err; } + if (flags & I915_ACTIVE_AWAIT_BARRIER) { + err = __await_barrier(ref, arg); + if (err) + return err; + } + return 0; } diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h index 4f9aa7bab514..c7d54d2302a2 100644 --- a/drivers/gpu/drm/i915/i915_active.h +++ b/drivers/gpu/drm/i915/i915_active.h @@ -193,7 +193,8 @@ int i915_sw_fence_await_active(struct i915_sw_fence *fence, int i915_request_await_active(struct i915_request *rq, struct i915_active *ref, unsigned int flags); -#define I915_ACTIVE_AWAIT_ALL BIT(0) +#define I915_ACTIVE_AWAIT_ACTIVE BIT(0) +#define I915_ACTIVE_AWAIT_BARRIER BIT(1) int i915_active_acquire(struct i915_active *ref); bool i915_active_acquire_if_busy(struct i915_active *ref); -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
