Re: [igt-dev] [PATCH i-g-t v21 01/35] lib/gem_submission: Add gem_has_relocations() check

Add check which probes kernel supports relocation or not
for i915 device.

Signed-off-by: Zbigniew Kempczyński <redacted>
Signed-off-by: Chris Wilson <redacted>
Cc: Dominik Grzegorzek <redacted>
Cc: Petri Latvala <redacted>
---
 lib/i915/gem_submission.c | 30 ++++++++++++++++++++++++++++++
 lib/i915/gem_submission.h |  1 +
 2 files changed, 31 insertions(+)

diff --git a/lib/i915/gem_submission.c b/lib/i915/gem_submission.c
index 320340a5d..051f9d046 100644
--- a/lib/i915/gem_submission.c
+++ b/lib/i915/gem_submission.c

@@ -398,3 +398,33 @@ unsigned int gem_submission_measure(int i915, unsigned int engine)
 
        return size;
 }
+
+/**
+ * gem_has_relocations:
+ * @fd: opened i915 drm file descriptor
+ *
+ * Feature test macro to query whether kernel allows for generation to
+ * use relocations.
+ *
+ * Returns: true if we can use relocations, otherwise false
+ */
+
+bool gem_has_relocations(int i915)
+{
+       struct drm_i915_gem_relocation_entry reloc = {};
+       struct drm_i915_gem_exec_object2 obj = {
+               .handle = gem_create(i915, 4096),
+               .relocs_ptr = to_user_pointer(&reloc),
+               .relocation_count = 1,
+       };
+       struct drm_i915_gem_execbuffer2 execbuf = {
+               .buffers_ptr = to_user_pointer(&obj),
+               .buffer_count = 1,
+       };
+       bool has_relocs;
+
+       has_relocs = __gem_execbuf(i915, &execbuf) == -ENOENT;
+       gem_close(i915, obj.handle);