[PATCH v3 3/4] lib/gpgpu_shader: pass surface desription to shaders via inline data

[Andrzej Hajda]

Since newer architectures require stateless load/stores we need to pass
surface description to the shader. Instead of doing it for every call
we can use inline data which is passed by COMPUTE_WALKER and is stored
in GRF register r1.

Signed-off-by: Andrzej Hajda <andrzej.hajda at intel.com>
---
 lib/gpgpu_shader.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lib/gpgpu_shader.c b/lib/gpgpu_shader.c
index 363435e7efd3..518423158880 100644
--- a/lib/gpgpu_shader.c
+++ b/lib/gpgpu_shader.c
@@ -148,6 +148,16 @@ __xelp_gpgpu_execfunc(struct intel_bb *ibb,
 		      engine | I915_EXEC_NO_RELOC, false);
 }
 
+static void
+fill_inline_data(uint32_t *inline_data, uint64_t target_offset, struct intel_buf *target)
+{
+	igt_assert(target->surface[0].stride == intel_buf_width(target) * target->bpp/8);
+	*inline_data++ = lower_32_bits(target_offset);
+	*inline_data++ = upper_32_bits(target_offset);
+	*inline_data++ = target->surface[0].stride;
+	*inline_data++ = intel_buf_height(target);
+}
+
 static void
 __xehp_gpgpu_execfunc(struct intel_bb *ibb,
 		      struct intel_buf *target,
@@ -159,6 +169,7 @@ __xehp_gpgpu_execfunc(struct intel_bb *ibb,
 	struct xehp_interface_descriptor_data idd;
 	uint32_t sip_offset;
 	uint64_t engine;
+	uint32_t *inline_data;
 
 	intel_bb_add_intel_buf(ibb, target, true);
 
@@ -186,7 +197,10 @@ __xehp_gpgpu_execfunc(struct intel_bb *ibb,
 	if (sip_offset)
 		emit_sip(ibb, sip_offset);
 
+	/* Inline data is at 31th/32th dword of COMPUTE_WALKER, BSpec: 67028 */
+	inline_data = intel_bb_ptr(ibb) + 4 * (shdr->gen_ver < 2000 ? 31 : 32);
 	xehp_emit_compute_walk(ibb, 0, 0, x_dim * 16, y_dim, &idd, 0x0);
+	fill_inline_data(inline_data, CANONICAL(target->addr.offset), target);
 
 	intel_bb_out(ibb, MI_BATCH_BUFFER_END);
 	intel_bb_ptr_align(ibb, 32);
@@ -217,10 +231,18 @@ void gpgpu_shader_exec(struct intel_bb *ibb,
 		       struct gpgpu_shader *sip,
 		       uint64_t ring, bool explicit_engine)
 {
+	uint64_t ahnd;
+
 	igt_require(shdr->gen_ver >= SUPPORTED_GEN_VER);
 	igt_assert(ibb->size >= PAGE_SIZE);
 	igt_assert(ibb->ptr == ibb->batch);
 
+	ahnd = intel_allocator_open_full(ibb->fd, 0, 0, 0, INTEL_ALLOCATOR_SIMPLE,
+					 ALLOC_STRATEGY_LOW_TO_HIGH, 0);
+	target->addr.offset = intel_allocator_alloc(ahnd, target->handle,
+						    target->surface[0].size, 0);
+	intel_allocator_close(ahnd);
+
 	if (shdr->gen_ver >= 1250)
 		__xehp_gpgpu_execfunc(ibb, target, x_dim, y_dim, shdr, sip,
 				      ring, explicit_engine);

-- 
2.34.1