Add MCRF instruction

Hopefully it's not too timing catastrophic. The variable newcrf will
be handy for the other CR ops when we implement them I suspect.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

decode1.vhdl

@@ -120,7 +120,7 @@ architecture behaviour of decode1 is
 		--PPC_MADDHD
 		--PPC_MADDHDU
 		--PPC_MADDLD
-		--PPC_MCRF
+		PPC_MCRF       =>       (ALU,    OP_MCRF,      NONE,       NONE,        NONE, NONE, BF,   BFA,  NONE, '1', '1', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '1'),
 		--PPC_MCRXR
 		--PPC_MCRXRX
 		PPC_MFCR       =>       (ALU,    OP_MFCR,      NONE,       NONE,        NONE, RT,   NONE, NONE, NONE, '1', '0', '0', '0', NONE, '0', '0', '0', '0', '0', '0', NONE, '0', '1'),

decode2.vhdl

@@ -159,6 +159,8 @@ architecture behaviour of decode2 is
 			return "0" & insn_bi(insn_in);
 		when L =>
 			return "00000" & insn_l(insn_in);
+		when BFA =>
+			return "000" & insn_bfa(insn_in);
 		when NONE =>
 			return "000000";
 		end case;

decode_types.vhdl

@@ -64,7 +64,7 @@ package decode_types is
 	type input_reg_c_t is (NONE, RS);
 	type output_reg_a_t is (NONE, RT, RA);
 	type constant_a_t is (NONE, SH, SH32, FXM, BO, BF, TOO, BC);
-	type constant_b_t is (NONE, MB, ME, MB32, BI, L);
+	type constant_b_t is (NONE, MB, ME, MB32, BI, L, BFA);
 	type constant_c_t is (NONE, ME32, BH);
 	type rc_t is (NONE, ONE, RC);
 

execute1.vhdl

@@ -52,9 +52,11 @@ begin
 	execute1_1: process(all)
 		variable v : reg_type;
 		variable result : std_ulogic_vector(63 downto 0);
+		variable newcrf : std_ulogic_vector(3 downto 0);
 		variable result_with_carry : std_ulogic_vector(64 downto 0);
 		variable result_en : integer;
 		variable crnum : integer;
+		variable scrnum : integer;
 		variable lo, hi : integer;
 	begin
 		result := (others => '0');
@@ -183,6 +185,23 @@ begin
 						result := e_in.read_data2;
 					end if;
 					result_en := 1;
+				when OP_MCRF =>
+					v.e.write_cr_enable := '1';
+					crnum := to_integer(unsigned(e_in.const1(2 downto 0)));
+					scrnum := to_integer(unsigned(e_in.const2(2 downto 0)));
+					v.e.write_cr_mask := num_to_fxm(crnum);
+					for i in 0 to 7 loop
+					    lo := (7-i)*4;
+					    hi := lo + 3;
+					    if i = scrnum then
+						newcrf := e_in.cr(hi downto lo);
+					    end if;
+					end loop;
+					for i in 0 to 7 loop
+						lo := i*4;
+						hi := lo + 3;
+						v.e.write_cr_data(hi downto lo) := newcrf;
+					end loop;
 				when OP_MFCTR =>
 					result := ctrl.ctr;
 					result_en := 1;

insn_helpers.vhdl

@@ -18,6 +18,7 @@ package insn_helpers is
     function insn_rc (insn_in : std_ulogic_vector) return std_ulogic;
     function insn_bd (insn_in : std_ulogic_vector) return std_ulogic_vector;
     function insn_bf (insn_in : std_ulogic_vector) return std_ulogic_vector;
+    function insn_bfa (insn_in : std_ulogic_vector) return std_ulogic_vector;
     function insn_fxm (insn_in : std_ulogic_vector) return std_ulogic_vector;
     function insn_bo (insn_in : std_ulogic_vector) return std_ulogic_vector;
     function insn_bi (insn_in : std_ulogic_vector) return std_ulogic_vector;
@@ -112,6 +113,11 @@ package body insn_helpers is
         return insn_in(25 downto 23);
     end;
 
+    function insn_bfa (insn_in : std_ulogic_vector) return std_ulogic_vector is
+    begin
+        return insn_in(20 downto 18);
+    end;
+
     function insn_fxm (insn_in : std_ulogic_vector) return std_ulogic_vector is
     begin
         return insn_in(19 downto 12);