i965: Only enable ARB_query_buffer_object for newer kernels on Haswell.

On Haswell, we need version 6 of the kernel command parser in order to
write the math registers.  Our implementation of ARB_query_buffer_object
heavily relies on MI_MATH, so we should only advertise it when MI_MATH
is available.  We also need MI_LOAD_REGISTER_REG, which requires version
7 of the command parser.

To make these checks easier, introduce a screen->has_mi_math_and_lrr
flag that will be set when both commands are supported.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index db9d94d..f9b5484 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -1531,6 +1531,14 @@ __DRIconfig **intelInitScreen2(__DRIscreen *psp)
    if (ret == -1)
       intelScreen->cmd_parser_version = 0;
 
+   /* Haswell requires command parser version 6 in order to write to the
+    * MI_MATH GPR registers, and version 7 in order to use
+    * MI_LOAD_REGISTER_REG (which all users of MI_MATH use).
+    */
+   intelScreen->has_mi_math_and_lrr = intelScreen->devinfo->gen >= 8 ||
+                                      (intelScreen->devinfo->is_haswell &&
+                                       intelScreen->cmd_parser_version >= 7);
+
    psp->extensions = !intelScreen->has_context_reset_notification
       ? intelScreenExtensions : intelRobustScreenExtensions;