i965/drm: Make register write check handle execbuffer directly.

I'm about to rewrite how relocation handling works, at which point
drm_bacon_bo_emit_reloc() and drm_bacon_bo_mrb_exec() won't exist
anymore.  This code is already largely not using the batchbuffer
infrastructure, so just go all the way and handle relocations, the
validation list, and execbuffer ourselves.  That way, we don't have
to think the weird case where we only have a screen, and no context,
when redesigning the relocation handling.

v2: Write reloc.presumed_offset + reloc.delta into the batch, rather
    than duplicating the comment, so it's obvious that they match
    (suggested by Chris).  Also add a comment about why we don't do
    any error checking.

Reviewed-by: Chris Wilson <[email protected]>
Acked-by: Jason Ekstrand <[email protected]>

1 files changed, 34 insertions, 7 deletions

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index c973b448260..559575b6af8 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -1368,6 +1368,9 @@ static bool
 intel_detect_pipelined_register(struct intel_screen *screen,
                                 int reg, uint32_t expected_value, bool reset)
 {
+   if (screen->no_hw)
+      return false;
+
    drm_bacon_bo *results, *bo;
    uint32_t *batch;
    uint32_t offset = 0;
@@ -1395,11 +1398,14 @@ intel_detect_pipelined_register(struct intel_screen *screen,
    /* Save the register's value back to the buffer. */
    *batch++ = MI_STORE_REGISTER_MEM | (3 - 2);
    *batch++ = reg;
-   drm_bacon_bo_emit_reloc(bo, (char *)batch -(char *)bo->virtual,
-                           results, offset*sizeof(uint32_t),
-                           I915_GEM_DOMAIN_INSTRUCTION,
-                           I915_GEM_DOMAIN_INSTRUCTION);
-   *batch++ = ((uint32_t) results->offset64) + offset*sizeof(uint32_t);
+   struct drm_i915_gem_relocation_entry reloc = {
+      .offset = (char *) batch - (char *) bo->virtual,
+      .delta = offset * sizeof(uint32_t),
+      .target_handle = results->handle,
+      .read_domains = I915_GEM_DOMAIN_INSTRUCTION,
+      .write_domain = I915_GEM_DOMAIN_INSTRUCTION,
+   };
+   *batch++ = reloc.presumed_offset + reloc.delta;
 
    /* And afterwards clear the register */
    if (reset) {
@@ -1410,8 +1416,29 @@ intel_detect_pipelined_register(struct intel_screen *screen,
 
    *batch++ = MI_BATCH_BUFFER_END;
 
-   drm_bacon_bo_mrb_exec(bo, ALIGN((char *)batch - (char *)bo->virtual, 8),
-                         I915_EXEC_RENDER);
+   struct drm_i915_gem_exec_object2 exec_objects[2] = {
+      {
+         .handle = results->handle,
+      },
+      {
+         .handle = bo->handle,
+         .relocation_count = 1,
+         .relocs_ptr = (uintptr_t) &reloc,
+      }
+   };
+
+   struct drm_i915_gem_execbuffer2 execbuf = {
+      .buffers_ptr = (uintptr_t) exec_objects,
+      .buffer_count = 2,
+      .batch_len = ALIGN((char *) batch - (char *) bo->virtual, 8),
+      .flags = I915_EXEC_RENDER,
+   };
+
+   /* Don't bother with error checking - if the execbuf fails, the
+    * value won't be written and we'll just report that there's no access.
+    */
+   __DRIscreen *dri_screen = screen->driScrnPriv;
+   drmIoctl(dri_screen->fd, DRM_IOCTL_I915_GEM_EXECBUFFER2, &execbuf);
 
    /* Check whether the value got written. */
    if (drm_bacon_bo_map(results, false) == 0) {