Patch "drm/i915/gt: Serialize TLB invalidates with GT resets" has been added to the 5.18-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/i915/gt: Serialize TLB invalidates with GT resets

to the 5.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-gt-serialize-tlb-invalidates-with-gt-resets.patch
and it can be found in the queue-5.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit cd3fd76729a8c7c7c8c75d0b6e877775a129fdf5
Author: Chris Wilson <chris.p.wilson@xxxxxxxxx>
Date:   Tue Jul 12 16:21:33 2022 +0100

    drm/i915/gt: Serialize TLB invalidates with GT resets
    
    [ Upstream commit a1c5a7bf79c1faa5633b918b5c0666545e84c4d1 ]
    
    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.
    
    Cc: stable@xxxxxxxxxxxxxxx  # v4.4 and upper
    Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
    Reported-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
    Tested-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
    Reviewed-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
    Signed-off-by: Chris Wilson <chris.p.wilson@xxxxxxxxx>
    Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
    Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
    Acked-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
    Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
    Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/1e59a7c45dd919a530256b9ac721ac6ea86c0677.1657639152.git.mchehab@xxxxxxxxxx
    (cherry picked from commit 33da97894758737895e90c909f16786052680ef4)
    Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index 8a2483ccbfb9..f4375479e6f0 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -1012,6 +1012,20 @@ 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); /* serialise invalidate with GT reset */
+
+	for_each_engine(engine, gt, id) {
+		struct reg_and_bit rb;
+
+		rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
+		if (!i915_mmio_reg_offset(rb.reg))
+			continue;
+
+		intel_uncore_write_fw(uncore, rb.reg, rb.bit);
+	}
+
+	spin_unlock_irq(&uncore->lock);
+
 	for_each_engine(engine, gt, id) {
 		/*
 		 * HW architecture suggest typical invalidation time at 40us,
@@ -1026,7 +1040,6 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt)
 		if (!i915_mmio_reg_offset(rb.reg))
 			continue;
 
-		intel_uncore_write_fw(uncore, rb.reg, rb.bit);
 		if (__intel_wait_for_register_fw(uncore,
 						 rb.reg, rb.bit, 0,
 						 timeout_us, timeout_ms,