Should we gain per-client timelines, we can then utilise the separate HWSP in order to use MI_SEMAPHORE_MBOX with the unique GGTT addresses required for synchronising between clients across different engines. Teach the emit_semaphore_wait about MI_SEMAPHORE_MBOX for the older generations.
Note that the engine must still indicate support for the semaphore synchronisation before the context is allowed to use them. Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/i915_request.c | 31 +++++++++++++++++++---------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index c5d7220de529..9537e30f9439 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1016,7 +1016,7 @@ __emit_semaphore_wait(struct i915_request *to, int len, err; u32 *cs; - GEM_BUG_ON(INTEL_GEN(to->i915) < 8); + GEM_BUG_ON(INTEL_GEN(to->i915) < 6); GEM_BUG_ON(i915_request_has_initial_breadcrumb(to)); /* We need to pin the signaler's HWSP until we are finished reading. */ @@ -1040,17 +1040,26 @@ __emit_semaphore_wait(struct i915_request *to, * (post-wrap) values than they were expecting (and so wait * forever). */ - *cs++ = (MI_SEMAPHORE_WAIT | - MI_SEMAPHORE_GLOBAL_GTT | - MI_SEMAPHORE_POLL | - MI_SEMAPHORE_SAD_GTE_SDD) + - has_token; - *cs++ = seqno; - *cs++ = hwsp_offset; - *cs++ = 0; - if (has_token) { + if (INTEL_GEN(to->i915) >= 8) { + *cs++ = (MI_SEMAPHORE_WAIT | + MI_SEMAPHORE_GLOBAL_GTT | + MI_SEMAPHORE_POLL | + MI_SEMAPHORE_SAD_GTE_SDD) + + has_token; + *cs++ = seqno; + *cs++ = hwsp_offset; + *cs++ = 0; + if (has_token) { + *cs++ = 0; + *cs++ = MI_NOOP; + } + } else { + *cs++ = (MI_SEMAPHORE_MBOX | + MI_SEMAPHORE_GLOBAL_GTT | + MI_SEMAPHORE_COMPARE); + *cs++ = seqno - 1; /* COMPARE is a strict greater-than */ + *cs++ = hwsp_offset; *cs++ = 0; - *cs++ = MI_NOOP; } intel_ring_advance(to, cs); -- 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
