The patch below does not apply to the 4.14-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 stable@vger.kernel.org.

thanks,

greg k-h

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

From a1c5a7bf79c1faa5633b918b5c0666545e84c4d1 Mon Sep 17 00:00:00 2001 From: Chris Wilson chris.p.wilson@intel.com Date: Tue, 12 Jul 2022 16:21:33 +0100 Subject: [PATCH] drm/i915/gt: Serialize TLB invalidates with GT resets MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

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@vger.kernel.org # v4.4 and upper Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store") Reported-by: Mauro Carvalho Chehab mchehab@kernel.org Tested-by: Mauro Carvalho Chehab mchehab@kernel.org Reviewed-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Chris Wilson chris.p.wilson@intel.com Cc: Tvrtko Ursulin tvrtko.ursulin@linux.intel.com Reviewed-by: Andi Shyti andi.shyti@linux.intel.com Acked-by: Thomas Hellström thomas.hellstrom@linux.intel.com Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/1e59a7c45dd919a530256b9ac721ac... (cherry picked from commit 33da97894758737895e90c909f16786052680ef4) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index 51a0fe60c050..531af6ad7007 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -1209,6 +1209,20 @@ 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, @@ -1223,7 +1237,6 @@ 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,