wishbone: sdb auto crossbar mapping support

modules/wishbone/wishbone_pkg.vhd

@@ -92,7 +92,7 @@ package wishbone_pkg is
   constant c_sdb_device_length : natural := 512;  -- bits
   subtype  t_sdb_record is std_logic_vector(c_sdb_device_length-1 downto 0);
   type     t_sdb_record_array is array(natural range <>) of t_sdb_record;
-
+  
   type t_sdb_product is record
     vendor_id : std_logic_vector(63 downto 0);
     device_id : std_logic_vector(31 downto 0);
@@ -139,9 +139,8 @@ package wishbone_pkg is
     syn_date         : std_logic_vector(31 downto 0);
     syn_username     : string(1 to 15);
   end record t_sdb_synthesis;
-
-
   
+
   -- general crossbar building functions
   function f_sdb_create_array(g_enum_dev_id  : boolean := false;
                               g_dev_id_offs    : natural := 0;
@@ -170,6 +169,12 @@ package wishbone_pkg is
   function f_sdb_extract_repo_url(sdb_record : t_sdb_record) return t_sdb_repo_url;
   function f_sdb_extract_synthesis(sdb_record : t_sdb_record) return t_sdb_synthesis;
 
+  -- Automatic crossbar mapping functions
+  function f_sdb_auto_device(device : t_sdb_device; enable : boolean := true) return t_sdb_record;
+  function f_sdb_auto_bridge(bridge : t_sdb_bridge; enable : boolean := true) return t_sdb_record;
+  function f_sdb_auto_layout(records : t_sdb_record_array) return t_sdb_record_array;
+  function f_sdb_auto_sdb   (records : t_sdb_record_array) return t_wishbone_address;
+  
   -- For internal use by the crossbar
   function f_sdb_embed_product(product         : t_sdb_product) return std_logic_vector;  -- (319 downto 8)
   function f_sdb_embed_component(sdb_component : t_sdb_component; address : t_wishbone_address) return std_logic_vector;  -- (447 downto 8)
@@ -1130,6 +1135,136 @@ package body wishbone_pkg is
     return result;
   end;
   
+  function f_sdb_auto_device(device : t_sdb_device; enable : boolean)
+    return t_sdb_record
+  is
+    constant c_zero  : t_wishbone_address := (others => '0');
+    variable v_empty : t_sdb_record := (others => '0');
+  begin
+    v_empty(7 downto 0) := (others => '1');
+    if enable then
+      return f_sdb_embed_device(device, c_zero);
+    else
+      return v_empty;
+    end if;
+  end f_sdb_auto_device;
+  
+  function f_sdb_auto_bridge(bridge : t_sdb_bridge; enable : boolean)
+    return t_sdb_record
+  is
+    constant c_zero  : t_wishbone_address := (others => '0');
+    variable v_empty : t_sdb_record := (others => '0');
+  begin
+    v_empty(7 downto 0) := (others => '1');
+    if enable then
+      return f_sdb_embed_bridge(bridge, c_zero);
+    else
+      return v_empty;
+    end if;
+  end f_sdb_auto_bridge;
+  
+  subtype t_usdb_address is unsigned(63 downto 0);
+  type t_usdb_address_array is array(natural range <>) of t_usdb_address;
+  
+  -- We map devices by placing the smallest ones first.
+  -- This is guaranteed to pack the maximum number of devices in the smallest space.
+  -- If a device has an address != 0, we leave it alone and let the crossbar confirm
+  -- that the address does not cause a conflict.
+  function f_sdb_auto_layout_helper(records : t_sdb_record_array)
+    return t_usdb_address_array
+  is
+    alias c_records : t_sdb_record_array(records'length-1 downto 0) is records;
+    constant c_zero : t_usdb_address := (others => '0');
+    
+    constant c_used_entries : natural := c_records'length + 1;
+    constant c_rom_entries  : natural := 2**f_ceil_log2(c_used_entries);
+    constant c_rom_bytes    : natural := c_rom_entries * c_sdb_device_length / 8;
+        
+    variable v_component : t_sdb_component;
+    variable v_sizes     : t_usdb_address_array(c_records'length downto 0);
+    variable v_address   : t_usdb_address_array(c_records'length downto 0);
+    variable v_map       : std_logic_vector(c_records'length downto 0) := (others => '0');
+    variable v_cursor    : unsigned(63 downto 0) := (others => '0');
+    variable v_increment : unsigned(63 downto 0) := (others => '0');
+  begin
+    -- First, extract the length of the devices, ignoring those not to be mapped
+    for i in c_records'range loop
+      v_component := f_sdb_extract_component(c_records(i)(447 downto 8));
+      v_sizes(i)   := unsigned(v_component.addr_last);
+      v_address(i) := unsigned(v_component.addr_first);
+      
+      -- Silently round up to a power of two; the crossbar will give a warning for us
+      for j in 62 downto 0 loop
+        v_sizes(i)(j) := v_sizes(i)(j+1) or v_sizes(i)(j);
+      end loop;
+      
+      -- Only map devices/bridges at address zero
+      if v_address(i) = c_zero then
+        case c_records(i)(7 downto 0) is
+          when x"01" => v_map(i) := '1';
+          when x"02" => v_map(i) := '1';
+          when others => null;
+        end case;
+      end if;
+    end loop;
+    
+    -- Assign the SDB record a spot as well
+    v_address(c_records'length) := (others => '0');
+    v_sizes(c_records'length) := to_unsigned(c_rom_bytes-1, 64);
+    v_map(c_records'length) := '1';
+    
+    -- Start assigning addresses
+    for j in 0 to 63 loop
+      v_increment := (j => '1', others => '0');
+      
+      for i in 0 to c_records'length loop
+        if v_map(i) = '1' and v_sizes(i)(j) = '0' then
+          v_map(i) := '0';
+          v_address(i) := v_cursor;
+          v_cursor := v_cursor + v_increment;
+        end if;
+      end loop;
+      
+      -- Round up to the next required alignment
+      if v_cursor(j) = '1' then
+        v_cursor := v_cursor + v_increment;
+      end if;
+    end loop;
+    
+    return v_address;
+  end f_sdb_auto_layout_helper;
+  
+  function f_sdb_auto_layout(records : t_sdb_record_array)
+    return t_sdb_record_array
+  is
+    alias    c_records : t_sdb_record_array(records'length-1 downto 0) is records;
+    variable v_result  : t_sdb_record_array(c_records'range) := c_records;
+    constant c_address : t_usdb_address_array := f_sdb_auto_layout_helper(c_records);
+    variable v_address : t_wishbone_address;
+  begin
+    -- Put the addresses into the mapping
+    for i in v_result'range loop
+      v_address :=  std_logic_vector(c_address(i)(t_wishbone_address'range));
+
+      if c_records(i)(7 downto 0) = x"01" then
+        v_result(i) := f_sdb_embed_device(f_sdb_extract_device(v_result(i)), v_address);
+      end if;
+      if c_records(i)(7 downto 0) = x"02" then
+        v_result(i) := f_sdb_embed_bridge(f_sdb_extract_bridge(v_result(i)), v_address);
+      end if;
+    end loop;
+    
+    return v_result;
+  end f_sdb_auto_layout;
+  
+  function f_sdb_auto_sdb(records : t_sdb_record_array)
+    return t_wishbone_address
+  is
+    alias    c_records : t_sdb_record_array(records'length-1 downto 0) is records;
+    constant c_address : t_usdb_address_array(c_records'length downto 0) := f_sdb_auto_layout_helper(c_records);
+  begin
+    return std_logic_vector(c_address(c_records'length)(t_wishbone_address'range));
+  end f_sdb_auto_sdb;
 
 
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