i965/chv: Use kernel provided info for max_cs_threads

With the previous patches, the code can find out the actual number of available
compute threads. It is enabled only for Cherryview since that is the only
platform I know for a fact has shipped devices which can benefit from this.  It
seems like other platforms /might/ benefit from this because of fused
configurations which /might/ have shipped. Fallback code is still there.

v2: Some minor adjustments from Matt

Signed-off-by: Ben Widawsky <[email protected]>
Reviewed-by: Jordan Justen <[email protected]

1 files changed, 8 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index c66dd13373b..6e3f0a08432 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -929,7 +929,14 @@ brwCreateContext(gl_api api,
    brw->max_ds_threads = devinfo->max_ds_threads;
    brw->max_gs_threads = devinfo->max_gs_threads;
    brw->max_wm_threads = devinfo->max_wm_threads;
-   brw->max_cs_threads = devinfo->max_cs_threads;
+   /* FINISHME: Do this for all platforms that the kernel supports */
+   if (brw->is_cherryview &&
+       screen->subslice_total > 0 && screen->eu_total > 0) {
+      /* Logical CS threads = EUs per subslice * 7 threads per EU */
+      brw->max_cs_threads = screen->eu_total / screen->subslice_total * 7;
+   } else {
+      brw->max_cs_threads = devinfo->max_cs_threads;
+   }
    brw->urb.size = devinfo->urb.size;
    brw->urb.min_vs_entries = devinfo->urb.min_vs_entries;
    brw->urb.max_vs_entries = devinfo->urb.max_vs_entries;