swcore[new mpm]: page allocator (both old and new) modified to enable a new way…

swcore[new mpm]: page allocator (both old and new) modified to enable a new way of page usecnt handling: we store the usecnt only in the first page of the pck, the non-first pages have usecnt=1. When pck is sent on the output port, only the usecnt of the first page is decremented unless the usecnt==1, then we free all the pages allocated to the pck, so the page allocator needs to indicate if the usecnt is 1

swcore[new mpm]: page allocator (both old and new) modified to enable a new way…
swcore[new mpm]: page allocator (both old and new) modified to enable a new way of page usecnt handling: we store the usecnt only in the first page of the pck, the non-first pages have usecnt=1. When pck is sent on the output port, only the usecnt of the first page is decremented unless the usecnt==1, then we free all the pages allocated to the pck, so the page allocator needs to indicate if the usecnt is 1
2be45f53 · Maciej Lipinski · e58f99dd · 2be45f53 · 2be45f53 · 2be45f53
Commit 2be45f53 authored Feb 17, 2012 by Maciej Lipinski
3 changed files
--- a/modules/wrsw_swcore/swc_multiport_page_allocator.vhd
+++ b/modules/wrsw_swcore/swc_multiport_page_allocator.vhd
@@ -79,6 +79,8 @@ entity swc_multiport_page_allocator is
    usecnt_i          : in  std_logic_vector(g_num_ports * g_usecount_width - 1 downto 0);
    pgaddr_alloc_o    : out std_logic_vector(g_page_addr_width-1 downto 0);

+    free_last_pg_o    : out std_logic_vector(g_num_ports - 1 downto 0);
+
    nomem_o           : out std_logic
    );

@@ -152,7 +154,8 @@ architecture syn of swc_multiport_page_allocator is
  signal free_done_feedback  : std_logic_vector(g_num_ports-1 downto 0);
  signal free_done           : std_logic_vector(g_num_ports-1 downto 0);

-
+  signal free_last_pg      : std_logic_vector(g_num_ports-1 downto 0);
+  signal free_last_pg_feedback      : std_logic_vector(g_num_ports-1 downto 0);

  signal force_free_done_feedback  : std_logic_vector(g_num_ports-1 downto 0);
  signal force_free_done           : std_logic_vector(g_num_ports-1 downto 0);
@@ -161,7 +164,7 @@ architecture syn of swc_multiport_page_allocator is
  signal set_usecnt_done_feedback  : std_logic_vector(g_num_ports-1 downto 0);
 --  signal set_usecnt_done           : std_logic_vector(g_num_ports-1 downto 0);

-  
+  signal pg_free_last_pg            : std_logic;
 begin  -- syn


@@ -180,6 +183,7 @@ begin  -- syn
      rst_n_i        => rst_n_i,
      alloc_i        => pg_alloc,
      free_i         => pg_free,
+      free_last_pg_o => pg_free_last_pg,
      force_free_i   => pg_force_free,
      set_usecnt_i   => pg_set_usecnt,
      usecnt_i       => pg_usecnt,
@@ -259,6 +263,8 @@ begin  -- syn
        free_done_feedback        <= (others => '0');
        set_usecnt_done_feedback  <= (others => '0');
        force_free_done_feedback  <= (others => '0');
+        
+        free_last_pg              <= (others => '0');
      else

        -- recognizing on which port the allocation/deallocation/freeing process
@@ -274,8 +280,10 @@ begin  -- syn

            if(request_grant(1 downto 0) = b"01") then
               free_done_feedback(i)       <= '1';
+               free_last_pg_feedback(i)    <= pg_free_last_pg;                
            else
               free_done_feedback(i)       <= '0';
+               free_last_pg_feedback(i)    <= '0';
            end if;

            if(request_grant(1 downto 0) = b"10") then
@@ -293,6 +301,7 @@ begin  -- syn
          else
            alloc_done_feedback(i)       <= '0';
            free_done_feedback(i)        <= '0';
+            free_last_pg_feedback(i)     <= '0';
            set_usecnt_done_feedback(i)  <= '0';
            force_free_done_feedback(i)  <= '0';
          end if;
@@ -300,6 +309,7 @@ begin  -- syn

        alloc_done      <= alloc_done_feedback;
        free_done       <= free_done_feedback;
+        free_last_pg    <= free_last_pg_feedback;
       -- set_usecnt_done <= set_usecnt_done_feedback;
        force_free_done <= force_free_done_feedback;
      end if;
@@ -308,6 +318,7 @@ begin  -- syn

  alloc_done_o      <= alloc_done;
  free_done_o       <= free_done;
+  free_last_pg_o    <= free_last_pg;
  set_usecnt_done_o <= set_usecnt_done_feedback;--set_usecnt_done;
  force_free_done_o <= force_free_done;
  nomem_o           <= pg_nomem;

--- a/modules/wrsw_swcore/swc_page_alloc.vhd
+++ b/modules/wrsw_swcore/swc_page_alloc.vhd
@@ -157,6 +157,9 @@ entity swc_page_allocator_new is
    pgaddr_valid_o : out std_logic;

    idle_o : out std_logic;
+
+    free_last_pg_o : out std_logic;
+
    done_o : out std_logic;             -- "early" done output (active HI).
                                        -- Indicates that
                                        -- the alloc/release cycle is going to
@@ -327,4 +330,7 @@ ram_ones  <=(others => '1');
  nomem_o <= nomem;

  idle_o <= not (initializing or free_d0 or alloc_d0);
+  
+  free_last_pg_o <= (not initializing) when (free_d0 = '1' and unsigned(usecnt_rddata) = 1) else '0';
+  
 end syn;
--- a/modules/wrsw_swcore/swc_page_alloc_old.vhd
+++ b/modules/wrsw_swcore/swc_page_alloc_old.vhd
@@ -157,6 +157,7 @@ entity swc_page_allocator is

    pgaddr_o       : out std_logic_vector(g_page_addr_width -1 downto 0);
    pgaddr_valid_o : out std_logic;
+    free_last_pg_o : out std_logic;

    idle_o : out std_logic;
    done_o : out std_logic;             -- "early" done output (active HI).
@@ -615,4 +616,8 @@ begin  -- syn

  nomem_o <= nomem;

+  free_last_pg_o <= '1' when (state             = FREE_CHECK_USECNT and 
+                              usecnt_mem_rddata = std_logic_vector(to_unsigned(1, usecnt_mem_rddata'length ))) else
+                    '0';
+
 end syn;