[Intel-gfx] [PATCH 14/26] drm/i915/guc: Implement multi-lrc reset

Matthew Brost
2021-10-04T22:12:28Z

Update context and full GPU reset to work with multi-lrc. The idea is
parent context tracks all the active requests inflight for itself and
its' children. The parent context owns the reset replaying / canceling
requests as needed.

v2:
(John Harrison)
- Simply loop in find active request
- Add comments to find ative request / reset loop

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
drivers/gpu/drm/i915/gt/intel_context.c | 15 +++-
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 69 ++++++++++++++-----
2 files changed, 63 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index c5bb7ccfb3f8..3b340eb59ada 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -528,20 +528,29 @@ struct i915_request *intel_context_create_request(struct intel_context *ce)

struct i915_request *intel_context_find_active_request(struct intel_context *ce)
{
+ struct intel_context *parent = intel_context_to_parent(ce);
struct i915_request *rq, *active = NULL;
unsigned long flags;

GEM_BUG_ON(!intel_engine_uses_guc(ce->engine));

- spin_lock_irqsave(&ce->guc_state.lock, flags);
- list_for_each_entry_reverse(rq, &ce->guc_state.requests,
+ /*
+ * We search the parent list to find an active request on the submitted
+ * context. The parent list contains the requests for all the contexts
+ * in the relationship so we have to do a compare of each request's
+ * context must be done.
+ */
+ spin_lock_irqsave(&parent->guc_state.lock, flags);
+ list_for_each_entry_reverse(rq, &parent->guc_state.requests,
sched.link) {
+ if (rq->context != ce)
+ continue;
if (i915_request_completed(rq))
break;

active = rq;
}
- spin_unlock_irqrestore(&ce->guc_state.lock, flags);
+ spin_unlock_irqrestore(&parent->guc_state.lock, flags);

return active;
}
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 6be7adf89e4f..d661a69ef4f7 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -681,6 +681,11 @@ static inline int rq_prio(const struct i915_request *rq)
return rq->sched.attr.priority;
}

+static inline bool is_multi_lrc(struct intel_context *ce)
+{
+ return intel_context_is_parallel(ce);
+}
+
static bool is_multi_lrc_rq(struct i915_request *rq)
{
return intel_context_is_parallel(rq->context);
@@ -1214,10 +1219,15 @@ __unwind_incomplete_requests(struct intel_context *ce)

static void __guc_reset_context(struct intel_context *ce, bool stalled)
{
+ bool local_stalled;
struct i915_request *rq;
unsigned long flags;
u32 head;
+ int i, number_children = ce->parallel.number_children;
bool skip = false;
+ struct intel_context *parent = ce;
+
+ GEM_BUG_ON(intel_context_is_child(ce));

intel_context_get(ce);

@@ -1243,25 +1253,38 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
if (unlikely(skip))
goto out_put;

- rq = intel_context_find_active_request(ce);
- if (!rq) {
- head = ce->ring->tail;
- stalled = false;
- goto out_replay;
- }
+ /*
+ * For each context in the relationship find the hanging request
+ * resetting each context / request as needed
+ */
+ for (i = 0; i < number_children + 1; ++i) {
+ if (!intel_context_is_pinned(ce))
+ goto next_context;
+
+ local_stalled = false;
+ rq = intel_context_find_active_request(ce);
+ if (!rq) {
+ head = ce->ring->tail;
+ goto out_replay;
+ }

- if (!i915_request_started(rq))
- stalled = false;
+ GEM_BUG_ON(i915_active_is_idle(&ce->active));
+ head = intel_ring_wrap(ce->ring, rq->head);

- GEM_BUG_ON(i915_active_is_idle(&ce->active));
- head = intel_ring_wrap(ce->ring, rq->head);
- __i915_request_reset(rq, stalled);
+ if (i915_request_started(rq))
+ local_stalled = true;

+ __i915_request_reset(rq, local_stalled && stalled);
out_replay:
- guc_reset_state(ce, head, stalled);
- __unwind_incomplete_requests(ce);
+ guc_reset_state(ce, head, local_stalled && stalled);
+next_context:
+ if (i != number_children)
+ ce = list_next_entry(ce, parallel.child_link);
+ }
+
+ __unwind_incomplete_requests(parent);
out_put:
- intel_context_put(ce);
+ intel_context_put(parent);
}

void intel_guc_submission_reset(struct intel_guc *guc, bool stalled)
@@ -1282,7 +1305,8 @@ void intel_guc_submission_reset(struct intel_guc *guc, bool stalled)

xa_unlock(&guc->context_lookup);

- if (intel_context_is_pinned(ce))
+ if (intel_context_is_pinned(ce) &&
+ !intel_context_is_child(ce))
__guc_reset_context(ce, stalled);

intel_context_put(ce);
@@ -1374,7 +1398,8 @@ void intel_guc_submission_cancel_requests(struct intel_guc *guc)

xa_unlock(&guc->context_lookup);

- if (intel_context_is_pinned(ce))
+ if (intel_context_is_pinned(ce) &&
+ !intel_context_is_child(ce))
guc_cancel_context_requests(ce);

intel_context_put(ce);
@@ -2067,6 +2092,8 @@ static struct i915_sw_fence *guc_context_block(struct intel_context *ce)
u16 guc_id;
bool enabled;

+ GEM_BUG_ON(intel_context_is_child(ce));
+
spin_lock_irqsave(&ce->guc_state.lock, flags);

incr_context_blocked(ce);
@@ -2121,6 +2148,7 @@ static void guc_context_unblock(struct intel_context *ce)
bool enable;

GEM_BUG_ON(context_enabled(ce));
+ GEM_BUG_ON(intel_context_is_child(ce));

spin_lock_irqsave(&ce->guc_state.lock, flags);

@@ -2147,11 +2175,14 @@ static void guc_context_unblock(struct intel_context *ce)
static void guc_context_cancel_request(struct intel_context *ce,
struct i915_request *rq)
{
+ struct intel_context *block_context =
+ request_to_scheduling_context(rq);
+
if (i915_sw_fence_signaled(&rq->submit)) {
struct i915_sw_fence *fence;

intel_context_get(ce);
- fence = guc_context_block(ce);
+ fence = guc_context_block(block_context);
i915_sw_fence_wait(fence);
if (!i915_request_completed(rq)) {
__i915_request_skip(rq);
@@ -2165,7 +2196,7 @@ static void guc_context_cancel_request(struct intel_context *ce,
*/
flush_work(&ce_to_guc(ce)->ct.requests.worker);

- guc_context_unblock(ce);
+ guc_context_unblock(block_context);
intel_context_put(ce);
}
}
@@ -2191,6 +2222,8 @@ static void guc_context_ban(struct intel_context *ce, struct i915_request *rq)
intel_wakeref_t wakeref;
unsigned long flags;

+ GEM_BUG_ON(intel_context_is_child(ce));
+
guc_flush_submissions(guc);

spin_lock_irqsave(&ce->guc_state.lock, flags);
--
2.32.0