ilo: print a warning when PPGTT is disabled

Despite what the PRMs say, the driver appears to work fine when PPGTT is
disabled.  But at least print a warning in that case.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/gallium/drivers/ilo/ilo_screen.c b/src/gallium/drivers/ilo/ilo_screen.c
index 5d652e4ad73..442e704615d 100644
--- a/src/gallium/drivers/ilo/ilo_screen.c
+++ b/src/gallium/drivers/ilo/ilo_screen.c
@@ -652,6 +652,7 @@ init_dev(struct ilo_dev_info *dev, const struct intel_winsys_info *info)
    dev->has_llc = info->has_llc;
    dev->has_address_swizzling = info->has_address_swizzling;
    dev->has_logical_context = info->has_logical_context;
+   dev->has_ppgtt = info->has_ppgtt;
    dev->has_timestamp = info->has_timestamp;
    dev->has_gen7_sol_reset = info->has_gen7_sol_reset;
 
@@ -661,6 +662,24 @@ init_dev(struct ilo_dev_info *dev, const struct intel_winsys_info *info)
    }
 
    /*
+    * PIPE_CONTROL and MI_* use PPGTT writes on GEN7+ and privileged GGTT
+    * writes on GEN6.
+    *
+    * From the Sandy Bridge PRM, volume 1 part 3, page 101:
+    *
+    *     "[DevSNB] When Per-Process GTT Enable is set, it is assumed that all
+    *      code is in a secure environment, independent of address space.
+    *      Under this condition, this bit only specifies the address space
+    *      (GGTT or PPGTT). All commands are executed "as-is""
+    *
+    * We need PPGTT to be enabled on GEN6 too.
+    */
+   if (!dev->has_ppgtt) {
+      /* experiments show that it does not really matter... */
+      ilo_warn("PPGTT disabled\n");
+   }
+
+   /*
     * From the Sandy Bridge PRM, volume 4 part 2, page 18:
     *
     *     "[DevSNB]: The GT1 product's URB provides 32KB of storage, arranged