drm/i915/gtt: Only keep gen6 page directories pinned while active

In order to be able to evict the gen6 ppgtt, we have to unpin it at some
point. We can simply use our context activity tracking to know when the
ppgtt is no longer in use by hardware, and so only keep it pinned while
being used a request.

For the kernel_context (and thus aliasing_ppgtt), it remains pinned at
all times, as the kernel_context itself is pinned at all times.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180614094103.18025-5-chris@chris-wilson.co.uk

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 735622dc73ec..6a937a896651 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1179,6 +1179,27 @@ static void intel_ring_context_destroy(struct intel_context *ce)
 		__i915_gem_object_release_unless_active(ce->state->obj);
 }
 
+static int __context_pin_ppgtt(struct i915_gem_context *ctx)
+{
+	struct i915_hw_ppgtt *ppgtt;
+	int err = 0;
+
+	ppgtt = ctx->ppgtt ?: ctx->i915->mm.aliasing_ppgtt;
+	if (ppgtt)
+		err = gen6_ppgtt_pin(ppgtt);
+
+	return err;
+}
+
+static void __context_unpin_ppgtt(struct i915_gem_context *ctx)
+{
+	struct i915_hw_ppgtt *ppgtt;
+
+	ppgtt = ctx->ppgtt ?: ctx->i915->mm.aliasing_ppgtt;
+	if (ppgtt)
+		gen6_ppgtt_unpin(ppgtt);
+}
+
 static int __context_pin(struct intel_context *ce)
 {
 	struct i915_vma *vma;
@@ -1227,6 +1248,7 @@ static void __context_unpin(struct intel_context *ce)
 
 static void intel_ring_context_unpin(struct intel_context *ce)
 {
+	__context_unpin_ppgtt(ce->gem_context);
 	__context_unpin(ce);
 
 	i915_gem_context_put(ce->gem_context);
@@ -1324,6 +1346,10 @@ __ring_context_pin(struct intel_engine_cs *engine,
 	if (err)
 		goto err;
 
+	err = __context_pin_ppgtt(ce->gem_context);
+	if (err)
+		goto err_unpin;
+
 	i915_gem_context_get(ctx);
 
 	/* One ringbuffer to rule them all */
@@ -1332,6 +1358,8 @@ __ring_context_pin(struct intel_engine_cs *engine,
 
 	return ce;
 
+err_unpin:
+	__context_unpin(ce);
 err:
 	ce->pin_count = 0;
 	return ERR_PTR(err);