From: Chris Wilson chris.p.wilson@intel.com
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 ---
See [PATCH v5 0/2] at: https://lore.kernel.org/all/cover.1657639152.git.mchehab@kernel.org/
drivers/gpu/drm/i915/gt/intel_gt.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index 8da3314bb6bf..68c2b0d8f187 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -952,6 +952,20 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt) mutex_lock(>->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, @@ -966,7 +980,6 @@ 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,