From 8a2fd47a78309715c827263a09e68de04be3ee6b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 13 Jan 2020 15:45:55 +0000
Subject: drm/i915/gem: Take local vma references for the parser
Git-commit: 01c1b2cbf05224495eec2cf54166934f123bad61
Patch-mainline: v5.6-rc2
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Take and hold a reference to each of the vma (and their objects) as we
process them with the cmdparser. This stops them being freed during the
work if the GEM execbuf is interrupted and the request we expected to
keep the objects alive is incomplete.

Fixes: 686c7c35abc2 ("drm/i915/gem: Asynchronous cmdparser")
Closes: https://gitlab.freedesktop.org/drm/intel/issues/970
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200113154555.1909639-1-chris@chris-wilson.co.uk
(cherry picked from commit 36c8e356a76e147f0b631fd29838147c01b50d04)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 37 ++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index d5a0f5ae4a8b..60c984e10c4a 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1981,9 +1981,20 @@ static int __eb_parse(struct dma_fence_work *work)
 				       pw->trampoline);
 }
 
+static void __eb_parse_release(struct dma_fence_work *work)
+{
+	struct eb_parse_work *pw = container_of(work, typeof(*pw), base);
+
+	if (pw->trampoline)
+		i915_active_release(&pw->trampoline->active);
+	i915_active_release(&pw->shadow->active);
+	i915_active_release(&pw->batch->active);
+}
+
 static const struct dma_fence_work_ops eb_parse_ops = {
 	.name = "eb_parse",
 	.work = __eb_parse,
+	.release = __eb_parse_release,
 };
 
 static int eb_parse_pipeline(struct i915_execbuffer *eb,
@@ -1997,6 +2008,20 @@ static int eb_parse_pipeline(struct i915_execbuffer *eb,
 	if (!pw)
 		return -ENOMEM;
 
+	err = i915_active_acquire(&eb->batch->active);
+	if (err)
+		goto err_free;
+
+	err = i915_active_acquire(&shadow->active);
+	if (err)
+		goto err_batch;
+
+	if (trampoline) {
+		err = i915_active_acquire(&trampoline->active);
+		if (err)
+			goto err_shadow;
+	}
+
 	dma_fence_work_init(&pw->base, &eb_parse_ops);
 
 	pw->engine = eb->engine;
@@ -2006,7 +2031,9 @@ static int eb_parse_pipeline(struct i915_execbuffer *eb,
 	pw->shadow = shadow;
 	pw->trampoline = trampoline;
 
-	dma_resv_lock(pw->batch->resv, NULL);
+	err = dma_resv_lock_interruptible(pw->batch->resv, NULL);
+	if (err)
+		goto err_trampoline;
 
 	err = dma_resv_reserve_shared(pw->batch->resv, 1);
 	if (err)
@@ -2034,6 +2061,14 @@ static int eb_parse_pipeline(struct i915_execbuffer *eb,
 
 err_batch_unlock:
 	dma_resv_unlock(pw->batch->resv);
+err_trampoline:
+	if (trampoline)
+		i915_active_release(&trampoline->active);
+err_shadow:
+	i915_active_release(&shadow->active);
+err_batch:
+	i915_active_release(&eb->batch->active);
+err_free:
 	kfree(pw);
 	return err;
 }
-- 
2.28.0