From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 8 May 2018 22:03:18 +0100
Subject: drm/i915/guc: Make submission tasklet hardirq safe
Git-commit: 6486d84b1cca1b4374286ba2685161824f0bfa7d
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Prepare to allow the GuC submission to be run from underneath a
hardirq timer context (and not just the current softirq context) as is
required for fast preemption resets and context switches.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508210318.10274-2-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/intel_guc_submission.c | 34 ++++++++++++++++++++--------
1 file changed, 25 insertions(+), 9 deletions(-)
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -669,7 +669,7 @@ static inline int port_prio(const struct
return rq_prio(port_request(port));
}
-static void guc_dequeue(struct intel_engine_cs *engine)
+static bool __guc_dequeue(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
struct execlist_port *port = execlists->port;
@@ -679,7 +679,8 @@ static void guc_dequeue(struct intel_eng
bool submit = false;
struct rb_node *rb;
- spin_lock_irq(&engine->timeline.lock);
+ lockdep_assert_held(&engine->timeline.lock);
+
rb = execlists->first;
GEM_BUG_ON(rb_first(&execlists->queue) != rb);
@@ -694,13 +695,13 @@ static void guc_dequeue(struct intel_eng
EXECLISTS_ACTIVE_PREEMPT);
queue_work(engine->i915->guc.preempt_wq,
&preempt_work->work);
- goto unlock;
+ return false;
}
}
port++;
if (port_isset(port))
- goto unlock;
+ return false;
}
GEM_BUG_ON(port_isset(port));
@@ -738,19 +739,34 @@ static void guc_dequeue(struct intel_eng
done:
execlists->queue_priority = rb ? to_priolist(rb)->priority : INT_MIN;
execlists->first = rb;
- if (submit) {
+ if (submit)
port_assign(port, last);
+ if (last)
execlists_user_begin(execlists, execlists->port);
- guc_submit(engine);
- }
/* We must always keep the beast fed if we have work piled up */
GEM_BUG_ON(port_isset(execlists->port) &&
!execlists_is_active(execlists, EXECLISTS_ACTIVE_USER));
GEM_BUG_ON(execlists->first && !port_isset(execlists->port));
-unlock:
- spin_unlock_irq(&engine->timeline.lock);
+ return submit;
+}
+
+static void guc_dequeue(struct intel_engine_cs *engine)
+{
+ unsigned long flags;
+ bool submit;
+
+ local_irq_save(flags);
+
+ spin_lock(&engine->timeline.lock);
+ submit = __guc_dequeue(engine);
+ spin_unlock(&engine->timeline.lock);
+
+ if (submit)
+ guc_submit(engine);
+
+ local_irq_restore(flags);
}
static void guc_submission_tasklet(unsigned long data)