[Intel-gfx] [PATCH] drm/i915/gt: Turn vm off then on again for gen7 mm switch
Chris Wilson
chris at chris-wilson.co.uk
Sun Dec 8 10:37:35 UTC 2019
"Have you tried switching it off and on again?"
Set the size of the mm to 0 to disable all PD cachelines, before
enabling the whole mm again. Let's see if that tricks the TLB into
reloading.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
.../gpu/drm/i915/gt/intel_ring_submission.c | 20 ++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
index f66220f3c0e6..de1050250782 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
@@ -1365,7 +1365,9 @@ static const struct intel_context_ops ring_context_ops = {
.destroy = ring_context_destroy,
};
-static int load_pd_dir(struct i915_request *rq, const struct i915_ppgtt *ppgtt)
+static int load_pd_dir(struct i915_request *rq,
+ const struct i915_ppgtt *ppgtt,
+ u32 valid)
{
const struct intel_engine_cs * const engine = rq->engine;
u32 *cs;
@@ -1376,7 +1378,7 @@ static int load_pd_dir(struct i915_request *rq, const struct i915_ppgtt *ppgtt)
*cs++ = MI_LOAD_REGISTER_IMM(1);
*cs++ = i915_mmio_reg_offset(RING_PP_DIR_DCLV(engine->mmio_base));
- *cs++ = PP_DIR_DCLV_2G;
+ *cs++ = valid;
*cs++ = MI_STORE_REGISTER_MEM | MI_SRM_LRM_GLOBAL_GTT;
*cs++ = i915_mmio_reg_offset(RING_PP_DIR_DCLV(engine->mmio_base));
@@ -1599,8 +1601,6 @@ static int switch_context(struct i915_request *rq)
GEM_BUG_ON(HAS_EXECLISTS(rq->i915));
if (vm) {
- int loops = 4; /* 2 for Haswell? 4 for Baytrail! */
-
/*
* Not only do we need a full barrier (post-sync write) after
* invalidating the TLBs, but we need to wait a little bit
@@ -1617,16 +1617,18 @@ static int switch_context(struct i915_request *rq)
if (ret)
return ret;
- do {
- ret = load_pd_dir(rq, i915_vm_to_ppgtt(vm));
- if (ret)
- return ret;
- } while (--loops);
+ ret = load_pd_dir(rq, i915_vm_to_ppgtt(vm), 0);
+ if (ret)
+ return ret;
ret = flush_tlb(rq);
if (ret)
return ret;
+ ret = load_pd_dir(rq, i915_vm_to_ppgtt(vm), PP_DIR_DCLV_2G);
+ if (ret)
+ return ret;
+
ret = rq->engine->emit_flush(rq, EMIT_FLUSH);
if (ret)
return ret;
--
2.24.0
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