[PATCH 02/31] drm/i915/gt: Push engine stopping into reset-prepare
Chris Wilson
chris at chris-wilson.co.uk
Tue Jul 16 20:11:45 UTC 2019
Push the engine stop into the back reset_prepare (where it already was!)
This allows us to avoid dangerously setting the RING registers to 0 for
logical contexts. If we clear the register on a live context, those
invalid register values are recorded in the logical context state and
replayed (with hilarious results).
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/intel_lrc.c | 16 +++++-
drivers/gpu/drm/i915/gt/intel_reset.c | 58 ----------------------
drivers/gpu/drm/i915/gt/intel_ringbuffer.c | 40 ++++++++++++++-
3 files changed, 53 insertions(+), 61 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index a220575a69bc..8da23409c064 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2179,11 +2179,23 @@ static void execlists_reset_prepare(struct intel_engine_cs *engine)
__tasklet_disable_sync_once(&execlists->tasklet);
GEM_BUG_ON(!reset_in_progress(execlists));
- intel_engine_stop_cs(engine);
-
/* And flush any current direct submission. */
spin_lock_irqsave(&engine->active.lock, flags);
spin_unlock_irqrestore(&engine->active.lock, flags);
+
+ /*
+ * We stop engines, otherwise we might get failed reset and a
+ * dead gpu (on elk). Also as modern gpu as kbl can suffer
+ * from system hang if batchbuffer is progressing when
+ * the reset is issued, regardless of READY_TO_RESET ack.
+ * Thus assume it is best to stop engines on all gens
+ * where we have a gpu reset.
+ *
+ * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
+ *
+ * FIXME: Wa for more modern gens needs to be validated
+ */
+ intel_engine_stop_cs(engine);
}
static void reset_csb_pointers(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index 7ddedfb16aa2..55e2ddcbd215 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -135,47 +135,6 @@ void __i915_request_reset(struct i915_request *rq, bool guilty)
}
}
-static void gen3_stop_engine(struct intel_engine_cs *engine)
-{
- struct intel_uncore *uncore = engine->uncore;
- const u32 base = engine->mmio_base;
-
- GEM_TRACE("%s\n", engine->name);
-
- if (intel_engine_stop_cs(engine))
- GEM_TRACE("%s: timed out on STOP_RING\n", engine->name);
-
- intel_uncore_write_fw(uncore,
- RING_HEAD(base),
- intel_uncore_read_fw(uncore, RING_TAIL(base)));
- intel_uncore_posting_read_fw(uncore, RING_HEAD(base)); /* paranoia */
-
- intel_uncore_write_fw(uncore, RING_HEAD(base), 0);
- intel_uncore_write_fw(uncore, RING_TAIL(base), 0);
- intel_uncore_posting_read_fw(uncore, RING_TAIL(base));
-
- /* The ring must be empty before it is disabled */
- intel_uncore_write_fw(uncore, RING_CTL(base), 0);
-
- /* Check acts as a post */
- if (intel_uncore_read_fw(uncore, RING_HEAD(base)))
- GEM_TRACE("%s: ring head [%x] not parked\n",
- engine->name,
- intel_uncore_read_fw(uncore, RING_HEAD(base)));
-}
-
-static void stop_engines(struct intel_gt *gt, intel_engine_mask_t engine_mask)
-{
- struct intel_engine_cs *engine;
- intel_engine_mask_t tmp;
-
- if (INTEL_GEN(gt->i915) < 3)
- return;
-
- for_each_engine_masked(engine, gt->i915, engine_mask, tmp)
- gen3_stop_engine(engine);
-}
-
static bool i915_in_reset(struct pci_dev *pdev)
{
u8 gdrst;
@@ -607,23 +566,6 @@ int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
*/
intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
for (retry = 0; ret == -ETIMEDOUT && retry < retries; retry++) {
- /*
- * We stop engines, otherwise we might get failed reset and a
- * dead gpu (on elk). Also as modern gpu as kbl can suffer
- * from system hang if batchbuffer is progressing when
- * the reset is issued, regardless of READY_TO_RESET ack.
- * Thus assume it is best to stop engines on all gens
- * where we have a gpu reset.
- *
- * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
- *
- * WaMediaResetMainRingCleanup:ctg,elk (presumably)
- *
- * FIXME: Wa for more modern gens needs to be validated
- */
- if (retry)
- stop_engines(gt, engine_mask);
-
GEM_TRACE("engine_mask=%x\n", engine_mask);
preempt_disable();
ret = reset(gt, engine_mask, retry);
diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
index f1e571fa2e6d..213df144be15 100644
--- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
@@ -739,7 +739,45 @@ static int xcs_resume(struct intel_engine_cs *engine)
static void reset_prepare(struct intel_engine_cs *engine)
{
- intel_engine_stop_cs(engine);
+ struct intel_uncore *uncore = engine->uncore;
+ const u32 base = engine->mmio_base;
+
+ /*
+ * We stop engines, otherwise we might get failed reset and a
+ * dead gpu (on elk). Also as modern gpu as kbl can suffer
+ * from system hang if batchbuffer is progressing when
+ * the reset is issued, regardless of READY_TO_RESET ack.
+ * Thus assume it is best to stop engines on all gens
+ * where we have a gpu reset.
+ *
+ * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
+ *
+ * WaMediaResetMainRingCleanup:ctg,elk (presumably)
+ *
+ * FIXME: Wa for more modern gens needs to be validated
+ */
+ GEM_TRACE("%s\n", engine->name);
+
+ if (intel_engine_stop_cs(engine))
+ GEM_TRACE("%s: timed out on STOP_RING\n", engine->name);
+
+ intel_uncore_write_fw(uncore,
+ RING_HEAD(base),
+ intel_uncore_read_fw(uncore, RING_TAIL(base)));
+ intel_uncore_posting_read_fw(uncore, RING_HEAD(base)); /* paranoia */
+
+ intel_uncore_write_fw(uncore, RING_HEAD(base), 0);
+ intel_uncore_write_fw(uncore, RING_TAIL(base), 0);
+ intel_uncore_posting_read_fw(uncore, RING_TAIL(base));
+
+ /* The ring must be empty before it is disabled */
+ intel_uncore_write_fw(uncore, RING_CTL(base), 0);
+
+ /* Check acts as a post */
+ if (intel_uncore_read_fw(uncore, RING_HEAD(base)))
+ GEM_TRACE("%s: ring head [%x] not parked\n",
+ engine->name,
+ intel_uncore_read_fw(uncore, RING_HEAD(base)));
}
static void reset_ring(struct intel_engine_cs *engine, bool stalled)
--
2.22.0
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