i965: Pass the EGL/DRI context priority through to the kernel

Decode the EGL/DRI priority enum into the [-1023, 1023] range as
interpreted by the kernel and call DRM_I915_GEM_CONTEXT_SETPARAM to
adjust the priority. We use 0 as the default medium priority (also the
kernel default) and so only need adjust up or down. By only doing the
adjustment if not setting to medium, we can faithfully report any error
whilst setting without worrying about kernel version.

Signed-off-by: Chris Wilson <[email protected]>
Cc: Kenneth Graunke <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_bufmgr.c b/src/mesa/drivers/dri/i965/brw_bufmgr.c
index 7c5a9651eba..17036b53bcd 100644
--- a/src/mesa/drivers/dri/i965/brw_bufmgr.c
+++ b/src/mesa/drivers/dri/i965/brw_bufmgr.c
@@ -1299,6 +1299,25 @@ brw_create_hw_context(struct brw_bufmgr *bufmgr)
    return create.ctx_id;
 }
 
+int
+brw_hw_context_set_priority(struct brw_bufmgr *bufmgr,
+                            uint32_t ctx_id,
+                            int priority)
+{
+   struct drm_i915_gem_context_param p = {
+      .ctx_id = ctx_id,
+      .param = I915_CONTEXT_PARAM_PRIORITY,
+      .value = priority,
+   };
+   int err;
+
+   err = 0;
+   if (drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM, &p))
+      err = -errno;
+
+   return err;
+}
+
 void
 brw_destroy_hw_context(struct brw_bufmgr *bufmgr, uint32_t ctx_id)
 {