[igt-dev] [PATCH i-g-t] tests/api_intel_bb: Verify delta is properly added in emit relocation

[Zbigniew Kempczyński]

When delta is added to buffer address and sum exceeds 32bits verify
emit relocation contains properly set low + high address dwords.

References: https://patchwork.freedesktop.org/series/83644/

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
Reported-by: Imre Deak <imre.deak at intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 tests/i915/api_intel_bb.c | 84 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/tests/i915/api_intel_bb.c b/tests/i915/api_intel_bb.c
index 965a7dde..7678fbce 100644
--- a/tests/i915/api_intel_bb.c
+++ b/tests/i915/api_intel_bb.c
@@ -860,6 +860,87 @@ static void offset_control(struct buf_ops *bops)
 	intel_bb_destroy(ibb);
 }
 
+/*
+ * Idea of the test is to verify delta is properly added to address
+ * when emit_reloc() is called.
+ *
+ * We create 3 buffers aligned to 0x4000_0000, last one has to be
+ * at 0xc000_0000. Then we add 0x7000_0000 to get 0x1_3000_0000.
+ * We cannot use less buffers because delta is s32 (even if it is passed as
+ * u32) so maximum positive value is 0x7fff_ffff.
+ */
+#define DELTA_BUFFERS 3
+static void delta_check(struct buf_ops *bops)
+{
+	int i915 = buf_ops_get_fd(bops), i;
+	struct intel_bb *ibb;
+	struct intel_buf *buf[DELTA_BUFFERS], *target;
+	uint64_t default_alignment, offset;
+	uint32_t *ptr, hi, lo;
+	bool supports_48bit;
+
+	ibb = intel_bb_create_with_relocs(i915, PAGE_SIZE);
+	supports_48bit = ibb->supports_48b_address;
+	if (!supports_48bit)
+		intel_bb_destroy(ibb);
+	igt_require_f(supports_48bit, "We need 48bit ppgtt for testing\n");
+
+	if (debug_bb)
+		intel_bb_set_debug(ibb, true);
+
+	/* Alignment has to be power of 2, we need to do 3 buffers */
+	default_alignment = intel_bb_set_default_object_alignment(ibb, 0x40000000);
+	for (i = 0; i < ARRAY_SIZE(buf); i++) {
+		buf[i] = create_buf(bops, WIDTH, HEIGHT, COLOR_CC);
+		intel_bb_add_object(ibb, buf[i]->handle, intel_buf_bo_size(buf[i]),
+				    buf[i]->addr.offset, false);
+	}
+	intel_bb_set_default_object_alignment(ibb, default_alignment);
+
+	intel_bb_out(ibb, MI_BATCH_BUFFER_END);
+	intel_bb_ptr_align(ibb, 8);
+
+	intel_bb_exec(ibb, intel_bb_offset(ibb), I915_EXEC_DEFAULT, false);
+
+	target = buf[DELTA_BUFFERS - 1];
+	/* Last buffer should be @ 0xc000_0000 */
+	offset = intel_bb_get_object_offset(ibb, target->handle);
+	igt_assert(offset == 0xc0000000);
+
+	intel_bb_reset(ibb, false);
+
+	/*
+	 * We need to do this ugly hack to enforce using passed presumed_offsets
+	 * in add_object() otherwise -1 is used and relocation is performed.
+	 */
+	ibb->enforce_relocs = false;
+
+	intel_bb_add_object(ibb, target->handle, intel_buf_bo_size(target),
+			    offset, false);
+	intel_bb_out(ibb, MI_BATCH_BUFFER_END);
+	intel_bb_ptr_align(ibb, 8);
+
+	intel_bb_emit_reloc(ibb, target->handle,
+			    I915_GEM_DOMAIN_RENDER,
+			    I915_GEM_DOMAIN_RENDER,
+			    0x70000000, offset);
+
+	intel_bb_exec(ibb, intel_bb_offset(ibb), I915_EXEC_DEFAULT, false);
+
+	ptr = gem_mmap__device_coherent(i915, ibb->handle, 0, ibb->size, PROT_READ);
+	lo = ptr[2];
+	hi = ptr[3];
+	gem_munmap(ptr, ibb->size);
+
+	for (i = 0; i < ARRAY_SIZE(buf); i++)
+		intel_buf_destroy(buf[i]);
+	intel_bb_destroy(ibb);
+
+	/* Assert after all resources are freed */
+	igt_assert_f(lo == 0x30000000 && hi == 0x1,
+		     "intel-bb doesn't properly handle delta in emit relocation\n");
+}
+
 static void full_batch(struct buf_ops *bops)
 {
 	int i915 = buf_ops_get_fd(bops);
@@ -1150,6 +1231,9 @@ igt_main_args("dpib", NULL, help_str, opt_handler, NULL)
 	igt_subtest("offset-control")
 		offset_control(bops);
 
+	igt_subtest("delta-check")
+		delta_check(bops);
+
 	igt_subtest("full-batch")
 		full_batch(bops);
 
-- 
2.26.0