From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 28 Jun 2018 21:12:05 +0100
Subject: drm/i915/execlists: Pull CSB reset under the timeline.lock
Git-commit: d8857d541c67110cdcedb330e9677efdc9c5844d
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
In the following patch, we will process the CSB events under the
timeline.lock and not serialised by the tasklet. This also means that we
will need to protect access to common variables such as
execlists->csb_head with the timeline.lock during reset.
v2: Move sync_irq to avoid deadlocks between taking timeline.lock from
our interrupt handler.
v3: Kill off the synchronize_hardirq as it raises more questions than
answered; now we use the timeline.lock entirely for CSB serialisation
between the irq and elsewhere, we don't need to be so heavy handed with
flushing
v4: Treat request cancellation (wedging after failed reset) similarly
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180628201211.13837-3-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/intel_lrc.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -871,7 +871,6 @@ static void reset_irq(struct intel_engin
{
/* Mark all CS interrupts as complete */
smp_store_mb(engine->execlists.active, 0);
- synchronize_hardirq(engine->i915->drm.irq);
clear_gtiir(engine);
@@ -908,14 +907,12 @@ static void execlists_cancel_requests(st
* submission's irq state, we also wish to remind ourselves that
* it is irq state.)
*/
- local_irq_save(flags);
+ spin_lock_irqsave(&engine->timeline.lock, flags);
/* Cancel the requests on the HW and clear the ELSP tracker. */
execlists_cancel_port_requests(execlists);
reset_irq(engine);
- spin_lock(&engine->timeline.lock);
-
/* Mark all executing requests as skipped. */
list_for_each_entry(rq, &engine->timeline.requests, link) {
GEM_BUG_ON(!rq->global_seqno);
@@ -949,9 +946,7 @@ static void execlists_cancel_requests(st
execlists->first = NULL;
GEM_BUG_ON(port_isset(execlists->port));
- spin_unlock(&engine->timeline.lock);
-
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&engine->timeline.lock, flags);
}
static void process_csb(struct intel_engine_cs *engine)
@@ -1969,8 +1964,7 @@ static void execlists_reset(struct intel
engine->name, request ? request->global_seqno : 0,
intel_engine_get_seqno(engine));
- /* See execlists_cancel_requests() for the irq/spinlock split. */
- local_irq_save(flags);
+ spin_lock_irqsave(&engine->timeline.lock, flags);
/*
* Catch up with any missed context-switch interrupts.
@@ -1985,14 +1979,12 @@ static void execlists_reset(struct intel
reset_irq(engine);
/* Push back any incomplete requests for replay after the reset. */
- spin_lock(&engine->timeline.lock);
__unwind_incomplete_requests(engine);
- spin_unlock(&engine->timeline.lock);
/* Following the reset, we need to reload the CSB read/write pointers */
engine->execlists.csb_head = GEN8_CSB_ENTRIES - 1;
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&engine->timeline.lock, flags);
/*
* If the request was innocent, we leave the request in the ELSP