FAILED: patch "[PATCH] drm/i915: Don't use BAR mappings for ring buffers with LLC" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 85636167e3206c3fbd52254fc432991cc4e90194
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '[email protected]' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

85636167e320 ("drm/i915: Don't use BAR mappings for ring buffers with LLC") fa85bfd19c26 ("drm/i915: Update the helper to set correct mapping")
e09e903a6e89 ("drm/i915/selftests: Prepare execlists and lrc selftests for obj->mm.lock removal") 17b7ab92bec3 ("drm/i915/selftests: Prepare hangcheck for obj->mm.lock removal") d3ad29567d4e ("drm/i915/selftests: Prepare context selftest for obj->mm.lock removal") c858ffa17716 ("drm/i915: Lock ww in ucode objects correctly")
c05258889ed4 ("drm/i915: Add igt_spinner_pin() to allow for ww locking around spinner.") 6895649bf13f ("drm/i915/selftests: Set error returns")
a0d3fdb628b8 ("drm/i915/gt: Split logical ring contexts from execlist submission") d0d829e56674 ("drm/i915: split gen8+ flush and bb_start emission functions") 70a2b431c364 ("drm/i915/gt: Rename lrc.c to execlists_submission.c")
d33fcd798cb7 ("drm/i915/gt: Ignore dt==0 for reporting underflows")
09212e81e545 ("drm/i915/gt: Flush xcs before tgl breadcrumbs")
c10f6019d0b2 ("drm/i915/gt: Use the local HWSP offset during submission") 89db95377be4 ("drm/i915/gt: Confirm the context survives execution")
052e04f17056 ("drm/i915/selftests: Fix locking inversion in lrc selftest.") 47b086934f42 ("drm/i915: Make sure execbuffer always passes ww state to i915_vma_pin.") 3999a7087989 ("drm/i915: Rework intel_context pinning to do everything outside of pin_mutex") 2bf541ff6d06 ("drm/i915: Pin engine before pinning all objects, v5.") b49a7d51c32e ("drm/i915: Nuke arguments to eb_pin_engine")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 85636167e3206c3fbd52254fc432991cc4e90194 Mon Sep 17 00:00:00 2001
From: John Harrison <[email protected]>
Date: Wed, 15 Feb 2023 17:11:01 -0800
Subject: [PATCH] drm/i915: Don't use BAR mappings for ring buffers with LLC
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Direction from hardware is that ring buffers should never be mapped via the BAR on systems with LLC. There are too many caching pitfalls due to the way BAR accesses are routed. So it is safest to just not use it.

index fb1d2595392e..fb99143be98e 100644
@@ -53,7 +53,7 @@ int intel_ring_pin(struct intel_ring *ring, struct i915_gem_ww_ctx *ww)
 	if (unlikely(ret))
 		goto err_unpin;
 
-	if (i915_vma_is_map_and_fenceable(vma)) {
+	if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915)) {
 		addr = (void __force *)i915_vma_pin_iomap(vma);
 	} else {
 		int type = i915_coherent_map_type(vma->vm->i915, vma->obj, false);

@@ -98,7 +98,7 @@ void intel_ring_unpin(struct intel_ring *ring)
 		return;
 
 	i915_vma_unset_ggtt_write(vma);
-	if (i915_vma_is_map_and_fenceable(vma))
+	if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915))
 		i915_vma_unpin_iomap(vma);
 	else
 		i915_gem_object_unpin_map(vma->obj);

From: John Harrison <[email protected]>

Direction from hardware is that ring buffers should never be mapped via the BAR on systems with LLC. There are too many caching pitfalls due to the way BAR accesses are routed. So it is safest to just not use it.

---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 3b8218dd9bb1..979d130b24c4 100644
@@ -1083,7 +1083,7 @@ int intel_ring_pin(struct intel_ring *ring,
 	if (unlikely(ret))
 		return ret;
 
-	if (i915_vma_is_map_and_fenceable(vma))
+	if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915))
 		addr = (void __force *)i915_vma_pin_iomap(vma);
 	else
 		addr = i915_gem_object_pin_map(vma->obj, map);

@@ -1118,7 +1118,7 @@ void intel_ring_unpin(struct intel_ring *ring)
 	/* Discard any unused bytes beyond that submitted to hw. */
 	intel_ring_reset(ring, ring->tail);
 
-	if (i915_vma_is_map_and_fenceable(ring->vma))
+	if (i915_vma_is_map_and_fenceable(ring->vma) && !HAS_LLC(ring->vma->vm->i915))
 		i915_vma_unpin_iomap(ring->vma);
 	else
 		i915_gem_object_unpin_map(ring->vma->obj);

2.39.1