[6/6] drm/i915/gt: Serialize TLB invalidates with GT resets

Commit Message

Mauro Carvalho Chehab June 15, 2022, 3:27 p.m. UTC

From: Chris Wilson <[e-mail]>

Avoid trying to invalidate the TLB in the middle of performing an
engine reset, as this may result in the reset timing out. Currently,
the TLB invalidate is only serialised by its own mutex, forgoing the
uncore lock, but we can take the uncore->lock as well to serialise
the mmio access, thereby serialising with the GDRST.

Tested on a NUC5i7RYB, BIOS RYBDWi35.86A.0380.2019.0517.1530 with
i915 selftest/hangcheck.

Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")

Reported-by: Mauro Carvalho Chehab <[e-mail]>
Tested-by: Mauro Carvalho Chehab <[e-mail]>
Reviewed-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Chris Wilson <[e-mail]>
Cc: Tvrtko Ursulin <[e-mail]>
Cc: [e-mail]
Acked-by: Thomas Hellström <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
---

See [PATCH 0/6] at: https://lore.kernel.org/all/[e-mail]/

 drivers/gpu/drm/i915/gt/intel_gt.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Andi Shyti June 23, 2022, 11:18 a.m. UTC | #1

Hi Mauro,

On Wed, Jun 15, 2022 at 04:27:40PM +0100, Mauro Carvalho Chehab wrote:
> From: Chris Wilson <[e-mail]>
> 
> Avoid trying to invalidate the TLB in the middle of performing an
> engine reset, as this may result in the reset timing out. Currently,
> the TLB invalidate is only serialised by its own mutex, forgoing the
> uncore lock, but we can take the uncore->lock as well to serialise
> the mmio access, thereby serialising with the GDRST.
> 
> Tested on a NUC5i7RYB, BIOS RYBDWi35.86A.0380.2019.0517.1530 with
> i915 selftest/hangcheck.
> 
> Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
> 
> Reported-by: Mauro Carvalho Chehab <[e-mail]>
> Tested-by: Mauro Carvalho Chehab <[e-mail]>
> Reviewed-by: Mauro Carvalho Chehab <[e-mail]>
> Signed-off-by: Chris Wilson <[e-mail]>
> Cc: Tvrtko Ursulin <[e-mail]>
> Cc: [e-mail]
> Acked-by: Thomas Hellström <[e-mail]>
> Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Reviewed-by: Andi Shyti <[e-mail]>

Thanks,
Andi

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index fb4fd5273ca4..33eb93586858 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -1248,6 +1248,8 @@  void intel_gt_invalidate_tlbs(struct intel_gt *gt)
 	mutex_lock(&gt->tlb_invalidate_lock);
 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
 
+	spin_lock_irq(&uncore->lock); /* seralise invalidate with GT reset */
+
 	awake = 0;
 	for_each_engine(engine, gt, id) {
 		struct reg_and_bit rb;
@@ -1272,6 +1274,8 @@  void intel_gt_invalidate_tlbs(struct intel_gt *gt)
 	     IS_ALDERLAKE_P(i915)))
 		intel_uncore_write_fw(uncore, GEN12_OA_TLB_INV_CR, 1);
 
+	spin_unlock_irq(&uncore->lock);
+
 	for_each_engine_masked(engine, gt, awake, tmp) {
 		struct reg_and_bit rb;