[PATCH 2/3] drm/i915/execlists: Move request unwinding to a separate function

Chris Wilson
2017-09-25T12:49:41Z

In the future, we will want to unwind requests following a preemption
point. This requires the same steps as for unwinding upon a reset, so
extract the existing code to a separate function for later use.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_lrc.c | 53 +++++++++++++++++++++++++---------------
1 file changed, 33 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 2c07f3c08bd3..c84831c7ea4a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -348,6 +348,37 @@ lookup_priolist(struct intel_engine_cs *engine,
return ptr_pack_bits(p, first, 1);
}

+static void unwind_wa_tail(struct drm_i915_gem_request *rq)
+{
+ rq->tail = intel_ring_wrap(rq->ring,
+ rq->wa_tail - WA_TAIL_DWORDS*sizeof(u32));
+ assert_ring_tail_valid(rq->ring, rq->tail);
+}
+
+static void unwind_incomplete_requests(struct intel_engine_cs *engine)
+{
+ struct drm_i915_gem_request *rq, *rn;
+
+ lockdep_assert_held(&engine->timeline->lock);
+ list_for_each_entry_safe_reverse(rq, rn,
+ &engine->timeline->requests,
+ link) {
+ struct i915_priolist *p;
+
+ if (i915_gem_request_completed(rq))
+ return;
+
+ __i915_gem_request_unsubmit(rq);
+ unwind_wa_tail(rq);
+
+ p = lookup_priolist(engine,
+ &rq->priotree,
+ rq->priotree.priority);
+ list_add(&rq->priotree.link,
+ &ptr_mask_bits(p, 1)->requests);
+ }
+}
+
static inline void
execlists_context_status_change(struct drm_i915_gem_request *rq,
unsigned long status)
@@ -1378,7 +1409,6 @@ static void reset_common_ring(struct intel_engine_cs *engine,
struct drm_i915_gem_request *request)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
- struct drm_i915_gem_request *rq, *rn;
struct intel_context *ce;
unsigned long flags;

@@ -1396,21 +1426,7 @@ static void reset_common_ring(struct intel_engine_cs *engine,
execlist_cancel_port_requests(execlists);

/* Push back any incomplete requests for replay after the reset. */
- list_for_each_entry_safe_reverse(rq, rn,
- &engine->timeline->requests, link) {
- struct i915_priolist *p;
-
- if (i915_gem_request_completed(rq))
- break;
-
- __i915_gem_request_unsubmit(rq);
-
- p = lookup_priolist(engine,
- &rq->priotree,
- rq->priotree.priority);
- list_add(&rq->priotree.link,
- &ptr_mask_bits(p, 1)->requests);
- }
+ unwind_incomplete_requests(engine);

spin_unlock_irqrestore(&engine->timeline->lock, flags);

@@ -1447,10 +1463,7 @@ static void reset_common_ring(struct intel_engine_cs *engine,
intel_ring_update_space(request->ring);

/* Reset WaIdleLiteRestore:bdw,skl as well */
- request->tail =
- intel_ring_wrap(request->ring,
- request->wa_tail - WA_TAIL_DWORDS*sizeof(u32));
- assert_ring_tail_valid(request->ring, request->tail);
+ unwind_wa_tail(request);
}

static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
--
2.14.1