i965: Stop restoring the default L3 configuration on Kernel 4.16+.

Kernel 4.16 has proper context isolation, which means we can change
the L3 configuration without worrying about that leaking to other
newly created contexts, breaking the assumptions of other userspace.

So, disable our workaround to reprogram it back to the default.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>

diff --git a/src/mesa/drivers/dri/i965/intel_batchbuffer.c b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
index 8a2b421..d0999bb 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_batchbuffer.c
+++ b/src/mesa/drivers/dri/i965/intel_batchbuffer.c
@@ -739,9 +739,10 @@ brw_finish_batch(struct brw_context *brw)
    if (brw->batch.ring == RENDER_RING) {
       /* Work around L3 state leaks into contexts set MI_RESTORE_INHIBIT which
        * assume that the L3 cache is configured according to the hardware
-       * defaults.
+       * defaults.  On Kernel 4.16+, we no longer need to do this.
        */
-      if (devinfo->gen >= 7)
+      if (devinfo->gen >= 7 &&
+          !(brw->screen->kernel_features & KERNEL_ALLOWS_CONTEXT_ISOLATION))
          gen7_restore_default_l3_config(brw);
 
       if (devinfo->is_haswell) {

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index 768634d..f9e799f 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -2660,6 +2660,9 @@ __DRIconfig **intelInitScreen2(__DRIscreen *dri_screen)
    if (devinfo->gen >= 8 || screen->cmd_parser_version >= 5)
       screen->kernel_features |= KERNEL_ALLOWS_COMPUTE_DISPATCH;
 
+   if (intel_get_boolean(screen, I915_PARAM_HAS_CONTEXT_ISOLATION))
+      screen->kernel_features |= KERNEL_ALLOWS_CONTEXT_ISOLATION;
+
    const char *force_msaa = getenv("INTEL_FORCE_MSAA");
    if (force_msaa) {
       screen->winsys_msaa_samples_override =

diff --git a/src/mesa/drivers/dri/i965/intel_screen.h b/src/mesa/drivers/dri/i965/intel_screen.h
index ef2d089..a2bce92 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_screen.h
+++ b/src/mesa/drivers/dri/i965/intel_screen.h
@@ -81,6 +81,7 @@ struct intel_screen
 #define KERNEL_ALLOWS_COMPUTE_DISPATCH              (1<<4)
 #define KERNEL_ALLOWS_EXEC_CAPTURE                  (1<<5)
 #define KERNEL_ALLOWS_EXEC_BATCH_FIRST              (1<<6)
+#define KERNEL_ALLOWS_CONTEXT_ISOLATION             (1<<7)
 
    struct brw_bufmgr *bufmgr;