+struct push_bos {
+ struct {
+ struct iris_address addr;
+ uint32_t length;
+ } buffers[4];
+ int buffer_count;
+ uint32_t max_length;
+};
+
+static void
+setup_constant_buffers(struct iris_context *ice,
+ struct iris_batch *batch,
+ int stage,
+ struct push_bos *push_bos)
+{
+ struct iris_shader_state *shs = &ice->state.shaders[stage];
+ struct iris_compiled_shader *shader = ice->shaders.prog[stage];
+ struct brw_stage_prog_data *prog_data = (void *) shader->prog_data;
+
+ uint32_t push_range_sum = 0;
+
+ int n = 0;
+ for (int i = 0; i < 4; i++) {
+ const struct brw_ubo_range *range = &prog_data->ubo_ranges[i];
+
+ if (range->length == 0)
+ continue;
+
+ push_range_sum += range->length;
+
+ if (range->length > push_bos->max_length)
+ push_bos->max_length = range->length;
+
+ /* Range block is a binding table index, map back to UBO index. */
+ unsigned block_index = iris_bti_to_group_index(
+ &shader->bt, IRIS_SURFACE_GROUP_UBO, range->block);
+ assert(block_index != IRIS_SURFACE_NOT_USED);
+
+ struct pipe_shader_buffer *cbuf = &shs->constbuf[block_index];
+ struct iris_resource *res = (void *) cbuf->buffer;
+
+ assert(cbuf->buffer_offset % 32 == 0);
+
+ push_bos->buffers[n].length = range->length;
+ push_bos->buffers[n].addr =
+ res ? ro_bo(res->bo, range->start * 32 + cbuf->buffer_offset)
+ : ro_bo(batch->screen->workaround_bo, 0);
+ n++;
+ }
+
+ /* From the 3DSTATE_CONSTANT_XS and 3DSTATE_CONSTANT_ALL programming notes:
+ *
+ * "The sum of all four read length fields must be less than or
+ * equal to the size of 64."
+ */
+ assert(push_range_sum <= 64);
+
+ push_bos->buffer_count = n;
+}
+
+static void
+emit_push_constant_packets(struct iris_context *ice,
+ struct iris_batch *batch,
+ int stage,
+ const struct push_bos *push_bos)
+{
+ struct iris_compiled_shader *shader = ice->shaders.prog[stage];
+ struct brw_stage_prog_data *prog_data = (void *) shader->prog_data;
+
+ iris_emit_cmd(batch, GENX(3DSTATE_CONSTANT_VS), pkt) {
+ pkt._3DCommandSubOpcode = push_constant_opcodes[stage];
+ if (prog_data) {
+ /* The Skylake PRM contains the following restriction:
+ *
+ * "The driver must ensure The following case does not occur
+ * without a flush to the 3D engine: 3DSTATE_CONSTANT_* with
+ * buffer 3 read length equal to zero committed followed by a
+ * 3DSTATE_CONSTANT_* with buffer 0 read length not equal to
+ * zero committed."
+ *
+ * To avoid this, we program the buffers in the highest slots.
+ * This way, slot 0 is only used if slot 3 is also used.
+ */
+ int n = push_bos->buffer_count;
+ assert(n <= 4);
+ const unsigned shift = 4 - n;
+ for (int i = 0; i < n; i++) {
+ pkt.ConstantBody.ReadLength[i + shift] =
+ push_bos->buffers[i].length;
+ pkt.ConstantBody.Buffer[i + shift] = push_bos->buffers[i].addr;
+ }
+ }
+ }
+}
+
+#if GEN_GEN >= 12
+static void
+emit_push_constant_packet_all(struct iris_context *ice,
+ struct iris_batch *batch,
+ uint32_t shader_mask,
+ const struct push_bos *push_bos)
+{
+ if (!push_bos) {
+ iris_emit_cmd(batch, GENX(3DSTATE_CONSTANT_ALL), pc) {
+ pc.ShaderUpdateEnable = shader_mask;
+ }
+ return;
+ }
+
+ const uint32_t n = push_bos->buffer_count;
+ const uint32_t max_pointers = 4;
+ const uint32_t num_dwords = 2 + 2 * n;
+ uint32_t const_all[2 + 2 * max_pointers];
+ uint32_t *dw = &const_all[0];
+
+ assert(n <= max_pointers);
+ iris_pack_command(GENX(3DSTATE_CONSTANT_ALL), dw, all) {
+ all.DWordLength = num_dwords - 2;
+ all.ShaderUpdateEnable = shader_mask;
+ all.PointerBufferMask = (1 << n) - 1;
+ }
+ dw += 2;
+
+ for (int i = 0; i < n; i++) {
+ _iris_pack_state(batch, GENX(3DSTATE_CONSTANT_ALL_DATA),
+ dw + i * 2, data) {
+ data.PointerToConstantBuffer = push_bos->buffers[i].addr;
+ data.ConstantBufferReadLength = push_bos->buffers[i].length;
+ }
+ }
+ iris_batch_emit(batch, const_all, sizeof(uint32_t) * num_dwords);
+}
+#endif
+