diff options
| -rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index 5b9f69458c7d..b07d22de682f 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -328,6 +328,28 @@ static u32 ct_get_next_fence(struct intel_guc_ct *ct) return ++ct->requests.last_fence; } +static void write_barrier(struct intel_guc_ct *ct) +{ + struct intel_guc *guc = ct_to_guc(ct); + struct intel_gt *gt = guc_to_gt(guc); + + if (i915_gem_object_is_lmem(guc->ct.vma->obj)) { + GEM_BUG_ON(guc->send_regs.fw_domains); + /* + * This register is used by the i915 and GuC for MMIO based + * communication. Once we are in this code CTBs are the only + * method the i915 uses to communicate with the GuC so it is + * safe to write to this register (a value of 0 is NOP for MMIO + * communication). If we ever start mixing CTBs and MMIOs a new + * register will have to be chosen. + */ + intel_uncore_write_fw(gt->uncore, GEN11_SOFT_SCRATCH(0), 0); + } else { + /* wmb() sufficient for a barrier if in smem */ + wmb(); + } +} + /** * DOC: CTB Host to GuC request * @@ -411,6 +433,12 @@ static int ct_write(struct intel_guc_ct *ct, } GEM_BUG_ON(tail > size); + /* + * make sure H2G buffer update and LRC tail update (if this triggering a + * submission) are visible before updating the descriptor tail + */ + write_barrier(ct); + /* now update desc tail (back in bytes) */ desc->tail = tail * 4; return 0; |