From: Chris Wilson chris@chris-wilson.co.uk
[ Upstream commit b24dcf1dc507f69ed3b5c66c2b6a0209ae80d4d4 ]
Don't allow two engines to be reset in parallel, as they would both try to select a reset bit (and send requests to common registers) and wait on that register, at the same time. Serialize control of the reset requests/acks using the uncore->lock, which will also ensure that no other GT state changes at the same time as the actual reset.
Cc: stable@vger.kernel.org # v4.4 and upper Reported-by: Mika Kuoppala mika.kuoppala@linux.intel.com Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Acked-by: Mika Kuoppala mika.kuoppala@linux.intel.com Reviewed-by: Andi Shyti andi.shyti@intel.com Reviewed-by: Andrzej Hajda andrzej.hajda@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/e0a2d894e77aed7c2e36b0d1abdc7d... (cherry picked from commit 336561a914fc0c6f1218228718f633b31b7af1c3) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/i915/gt/intel_reset.c | 37 ++++++++++++++++++++------- 1 file changed, 28 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index b7c6d4462ec5..d57db66ac7ea 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -299,9 +299,9 @@ static int gen6_hw_domain_reset(struct intel_gt *gt, u32 hw_domain_mask) return err; }
-static int gen6_reset_engines(struct intel_gt *gt, - intel_engine_mask_t engine_mask, - unsigned int retry) +static int __gen6_reset_engines(struct intel_gt *gt, + intel_engine_mask_t engine_mask, + unsigned int retry) { struct intel_engine_cs *engine; u32 hw_mask; @@ -320,6 +320,20 @@ static int gen6_reset_engines(struct intel_gt *gt, return gen6_hw_domain_reset(gt, hw_mask); }
+static int gen6_reset_engines(struct intel_gt *gt, + intel_engine_mask_t engine_mask, + unsigned int retry) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(>->uncore->lock, flags); + ret = __gen6_reset_engines(gt, engine_mask, retry); + spin_unlock_irqrestore(>->uncore->lock, flags); + + return ret; +} + static struct intel_engine_cs *find_sfc_paired_vecs_engine(struct intel_engine_cs *engine) { int vecs_id; @@ -486,9 +500,9 @@ static void gen11_unlock_sfc(struct intel_engine_cs *engine) rmw_clear_fw(uncore, sfc_lock.lock_reg, sfc_lock.lock_bit); }
-static int gen11_reset_engines(struct intel_gt *gt, - intel_engine_mask_t engine_mask, - unsigned int retry) +static int __gen11_reset_engines(struct intel_gt *gt, + intel_engine_mask_t engine_mask, + unsigned int retry) { struct intel_engine_cs *engine; intel_engine_mask_t tmp; @@ -582,8 +596,11 @@ static int gen8_reset_engines(struct intel_gt *gt, struct intel_engine_cs *engine; const bool reset_non_ready = retry >= 1; intel_engine_mask_t tmp; + unsigned long flags; int ret;
+ spin_lock_irqsave(>->uncore->lock, flags); + for_each_engine_masked(engine, gt, engine_mask, tmp) { ret = gen8_engine_reset_prepare(engine); if (ret && !reset_non_ready) @@ -611,17 +628,19 @@ static int gen8_reset_engines(struct intel_gt *gt, * This is best effort, so ignore any error from the initial reset. */ if (IS_DG2(gt->i915) && engine_mask == ALL_ENGINES) - gen11_reset_engines(gt, gt->info.engine_mask, 0); + __gen11_reset_engines(gt, gt->info.engine_mask, 0);
if (GRAPHICS_VER(gt->i915) >= 11) - ret = gen11_reset_engines(gt, engine_mask, retry); + ret = __gen11_reset_engines(gt, engine_mask, retry); else - ret = gen6_reset_engines(gt, engine_mask, retry); + ret = __gen6_reset_engines(gt, engine_mask, retry);
skip_reset: for_each_engine_masked(engine, gt, engine_mask, tmp) gen8_engine_reset_cancel(engine);
+ spin_unlock_irqrestore(>->uncore->lock, flags); + return ret; }