platform/wavelet3d: implement shader writeback

1 files changed, 152 insertions, 11 deletions

diff --git a/platform/wavelet3d/gfx_shader_back.sv b/platform/wavelet3d/gfx_shader_back.sv
index c7b2855..4929192 100644
--- a/platform/wavelet3d/gfx_shader_back.sv
+++ b/platform/wavelet3d/gfx_shader_back.sv
@@ -1,13 +1,15 @@
 module gfx_shader_back
 import gfx::*;
 (
-	input  logic               clk,
-	                           rst_n,
+	input  logic                 clk,
+	                             rst_n,
 
-	       gfx_front_back.back back,
+	       gfx_front_back.back   back,
 
-	       gfx_regfile_io.ab   read_data,
-	       gfx_regfile_io.wb   reg_wb
+	       gfx_regfile_io.ab     read_data,
+	       gfx_regfile_io.wb     reg_wb,
+
+	       gfx_shader_setup.core setup
 );
 
 	logic abort;
@@ -30,6 +32,7 @@ import gfx::*;
 		.rst_n,
 		.op(back.execute.p0),
 		.wb(p0_wb.tx),
+		.wave(back.execute.wave),
 		.abort,
 		.read_data,
 		.in_valid(back.dispatch.valid)
@@ -41,6 +44,7 @@ import gfx::*;
 		.rst_n,
 		.op(back.execute.p1),
 		.wb(p1_wb.tx),
+		.wave(back.execute.wave),
 		.in_shake(p1_shake.rx),
 		.read_data
 	);
@@ -51,6 +55,7 @@ import gfx::*;
 		.rst_n,
 		.op(back.execute.p2),
 		.wb(p2_wb.tx),
+		.wave(back.execute.wave),
 		.in_shake(p2_shake.rx),
 		.read_data
 	);
@@ -61,6 +66,7 @@ import gfx::*;
 		.rst_n,
 		.op(back.execute.p3),
 		.wb(p3_wb.tx),
+		.wave(back.execute.wave),
 		.in_shake(p3_shake.rx),
 		.read_data
 	);
@@ -81,7 +87,10 @@ import gfx::*;
 		.clk,
 		.rst_n,
 		.wb(out_wb.rx),
-		.regs(reg_wb)
+		.regs(reg_wb),
+		.setup,
+		.loop_group(back.loop.group),
+		.loop_valid(back.loop.valid)
 	);
 
 endmodule
@@ -170,6 +179,7 @@ module gfx_shader_writeback_arbiter2_prio
 	//TODO
 	assign a.ready = out.ready;
 	assign b.ready = 0;
+
 	assign out.dest = a.dest;
 	assign out.lanes = a.lanes;
 	assign out.group = a.group;
@@ -177,18 +187,149 @@ module gfx_shader_writeback_arbiter2_prio
 	assign out.scalar = a.scalar;
 	assign out.writeback = a.writeback;
 
+	assign out.mask = a.mask;
+	assign out.mask_update = a.mask_update;
+
+	assign out.pc_add = a.pc_add;
+	assign out.pc_inc = a.pc_inc;
+	assign out.pc_update = a.pc_update;
+
 endmodule
 
 module gfx_shader_writeback
+import gfx::*;
 (
-	input  logic             clk,
-	                         rst_n,
+	input  logic                 clk,
+	                             rst_n,
+
+	       gfx_wb.rx             wb,
+
+	       gfx_regfile_io.wb     regs,
 
-	       gfx_wb.rx         wb,
+	output logic                 loop_valid,
+	output group_id              loop_group,
 
-	       gfx_regfile_io.wb regs
+	       gfx_shader_setup.core setup
 );
 
-	
+	struct
+	{
+		group_id  group;
+		word      lanes[SHADER_LANES];
+		pc_offset pc_add;
+		lane_mask mask;
+		vgpr_num  vgpr;
+		logic     pc_update,
+		          mask_update,
+		          vgpr_update;
+	} loop_hold[REGFILE_STAGES], loop_out;
+
+	logic loop_valid_hold[REGFILE_STAGES], loop_out_valid, mask_wb, scalar_wb,
+	      setup_gpr, setup_mask, setup_submit;
+
+	assign wb.ready = 1;
+
+	assign loop_out = loop_hold[REGFILE_STAGES - 1];
+	assign loop_out_valid = loop_valid_hold[REGFILE_STAGES - 1];
+
+	assign loop_valid = loop_out_valid | setup_submit;
+
+	assign regs.pc_back_group = wb.group;
+	assign regs.mask_back_group = wb.group;
+
+	assign regs.pc_wb_write = (loop_out_valid & loop_out.pc_update) | setup_submit;
+	assign regs.mask_wb_write = mask_wb | setup_mask;
+	assign regs.sgpr_write.write = scalar_wb | setup_gpr;
+
+	assign regs.vgpr_write.vgpr = loop_out.vgpr;
+	assign regs.vgpr_write.group = loop_out.group;
+
+	assign mask_wb = loop_out_valid & loop_out.mask_update;
+	assign scalar_wb = wb.valid & wb.writeback & wb.scalar;
+
+	always_comb begin
+		loop_group = setup.write.group;
+		regs.pc_wb = setup.write.pc;
+		regs.pc_wb_group = setup.write.group;
+
+		if (loop_out_valid) begin
+			loop_group = loop_out.group;
+			regs.pc_wb = regs.pc_back + word_ptr'(loop_out.pc_add);
+			regs.pc_wb_group = loop_out.group;
+		end
+
+		regs.mask_wb = setup.write.mask;
+		regs.mask_wb_group = setup.write.group;
+
+		if (mask_wb) begin
+			regs.mask_wb = loop_out.mask;
+			regs.mask_wb_group = loop_out.group;
+		end
+
+		regs.sgpr_write.data = setup.write.gpr_value;
+		regs.sgpr_write.sgpr = setup.write.gpr.sgpr;
+		regs.sgpr_write.group = setup.write.group;
+
+		if (scalar_wb) begin
+			regs.sgpr_write.data = wb.lanes[0];
+			regs.sgpr_write.sgpr = wb.dest.sgpr;
+			regs.sgpr_write.group = wb.group;
+		end
+
+		for (int i = 0; i < SHADER_LANES; ++i)
+			regs.vgpr_write.data[i] = loop_out.lanes[i];
+
+		regs.vgpr_write.mask = regs.mask_back;
+		if (~loop_out_valid | ~loop_out.vgpr_update)
+			regs.vgpr_write.mask = '0;
+	end
+
+	always_ff @(posedge clk) begin
+		// Blocking assignments por bug de verilator (ver for de lanes abajo)
+
+		for (int i = REGFILE_STAGES - 1; i > 0; --i)
+			loop_hold[i] = loop_hold[i - 1];
+
+		loop_hold[0].mask = wb.mask;
+		loop_hold[0].vgpr = wb.dest.vgpr.num;
+		loop_hold[0].group = wb.group;
+		loop_hold[0].pc_add = wb.pc_add;
+		loop_hold[0].pc_update = wb.pc_update;
+		loop_hold[0].mask_update = wb.mask_update;
+		loop_hold[0].vgpr_update = wb.writeback & ~wb.scalar;
+
+		// https://github.com/verilator/verilator/issues/4804
+		for (int i = 0; i < SHADER_LANES; ++i)
+			loop_hold[0].lanes[i] = wb.lanes[i];
+
+		if (wb.pc_inc)
+			loop_hold[0].pc_add = pc_offset'(1);
+	end
+
+	always_ff @(posedge clk or negedge rst_n)
+		if (~rst_n) begin
+			setup_gpr <= 0;
+			setup_mask <= 0;
+			setup_submit <= 0;
+
+			setup.set_done.gpr <= 0;
+			setup.set_done.mask <= 0;
+			setup.set_done.submit <= 0;
+
+			for (int i = 0; i < $size(loop_valid_hold); ++i)
+				loop_valid_hold[i] <= 0;
+		end else begin
+			setup_gpr <= (setup_gpr & scalar_wb) | setup.write.gpr_set;
+			setup_mask <= (setup_mask & mask_wb) | setup.write.mask_set;
+			setup_submit <= (setup_submit & loop_out_valid) | setup.write.pc_set;
+
+			setup.set_done.gpr <= setup_gpr & ~scalar_wb;
+			setup.set_done.mask <= setup_mask & ~mask_wb;
+			setup.set_done.submit <= setup_submit & ~loop_out_valid;
+
+			loop_valid_hold[0] <= wb.valid;
+			for (int i = 1; i < REGFILE_STAGES; ++i)
+				loop_valid_hold[i] <= loop_valid_hold[i - 1];
+		end
 
 endmodule