[igt-dev] [PATCH i-g-t 1/7] lib/gem_submission: Add kernel exec object alignment capability
From: Zbigniew Kempczyński <hidden>
Date: 2021-10-14 08:19:40
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
v2: rename to gem_allows_obj_alignment() (Ashutosh) With newer gens passing non-zero alignment will be forbidden. Add check which detects kernel supports it or not. Signed-off-by: Zbigniew Kempczyński <redacted> Cc: Petri Latvala <redacted> Cc: Ashutosh Dixit <redacted> --- lib/i915/gem_submission.c | 32 ++++++++++++++++++++++++++++++++ lib/i915/gem_submission.h | 1 + 2 files changed, 33 insertions(+)
diff --git a/lib/i915/gem_submission.c b/lib/i915/gem_submission.c
index f1af4f97c..2627b802c 100644
--- a/lib/i915/gem_submission.c
+++ b/lib/i915/gem_submission.c@@ -472,3 +472,35 @@ bool gem_has_relocations(int i915) return has_relocs; } + +/** + * gem_allows_obj_alignment + * @fd: opened i915 drm file descriptor + * + * Check does i915 driver allows setting object alignment in exec object to + * handle in kernel and adjust object offset accordingly. + * + * Returns: true if kernel supports setting offset to be aligned, otherwise + * false. + */ +bool gem_allows_obj_alignment(int fd) +{ + struct drm_i915_gem_exec_object2 obj = { + .handle = gem_create(fd, 4096), + }; + struct drm_i915_gem_execbuffer2 execbuf = { + .buffers_ptr = to_user_pointer(&obj), + .buffer_count = 1, + }; + bool ret; + const uint32_t bbe = MI_BATCH_BUFFER_END; + + gem_write(fd, obj.handle, 0, &bbe, sizeof(bbe)); + gem_execbuf(fd, &execbuf); + + obj.alignment = 0x2000; + ret = __gem_execbuf(fd, &execbuf) == 0; + gem_close(fd, obj.handle); + + return ret; +}
diff --git a/lib/i915/gem_submission.h b/lib/i915/gem_submission.h
index 9b3e2a4e5..38dd24a99 100644
--- a/lib/i915/gem_submission.h
+++ b/lib/i915/gem_submission.h@@ -55,5 +55,6 @@ unsigned int gem_submission_measure(int i915, const intel_ctx_cfg_t *cfg, void gem_test_all_engines(int fd); bool gem_has_relocations(int fd); +bool gem_allows_obj_alignment(int fd); #endif /* GEM_SUBMISSION_H */
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2.26.0