tlb_content now supports 512G pages

[soc.git] / src / TLB / ariane / tlb_content.py

diff --git a/src/TLB/ariane/tlb_content.py b/src/TLB/ariane/tlb_content.py
index 4ffd919eb3800750ffc2c23006342f16fae80071..3384c88502d469b5edc111ea0e1c8c2e84dced3d 100644 (file)
--- a/src/TLB/ariane/tlb_content.py
+++ b/src/TLB/ariane/tlb_content.py
@@ -5,17 +5,17 @@ from TLB.ariane.ptw import TLBUpdate, PTE
 
 class TLBEntry:
     def __init__(self, asid_width):
-        self.asid = Signal(asid_width)
+        self.asid = Signal(asid_width,name="ent_asid")
         # SV48 defines four levels of page tables
-        self.vpn0 = Signal(9)
-        self.vpn1 = Signal(9)
-        self.vpn2 = Signal(9)
-        self.vpn3 = Signal(9)
-        self.is_2M = Signal()
-        self.is_1G = Signal()
-        self.is_512G = Signal()
-        self.valid = Signal()
-
+        self.vpn0 = Signal(9,name="ent_vpn0")
+        self.vpn1 = Signal(9,name="ent_vpn1")
+        self.vpn2 = Signal(9,name="ent_vpn2")
+        self.vpn3 = Signal(9,name="ent_vpn3")
+        self.is_2M = Signal(name="ent_is_2M")
+        self.is_1G = Signal(name="ent_is_1G")
+        self.is_512G = Signal(name="ent_is_512G")
+        self.valid = Signal(name="ent_valid")
+        
     def flatten(self):
         return Cat(*self.ports())
 
@@ -25,6 +25,7 @@ class TLBEntry:
     def ports(self):
         return [self.asid, self.vpn0, self.vpn1, self.vpn2,
                 self.is_2M, self.is_1G, self.valid]
+        
 
 class TLBContent(Elaboratable):
     def __init__(self, pte_width, asid_width):
@@ -33,6 +34,7 @@ class TLBContent(Elaboratable):
         self.flush_i = Signal()  # Flush signal
         # Update TLB
         self.update_i = TLBUpdate(asid_width)
+        self.vpn3 = Signal(9)
         self.vpn2 = Signal(9)
         self.vpn1 = Signal(9)
         self.vpn0 = Signal(9)
@@ -50,42 +52,52 @@ class TLBContent(Elaboratable):
         m = Module()
 
         tags = TLBEntry(self.asid_width)
+        
+        
         content = Signal(self.pte_width)
 
         m.d.comb += [self.lu_hit_o.eq(0),
+                     self.lu_is_512G_o.eq(0),
                      self.lu_is_2M_o.eq(0),
                      self.lu_is_1G_o.eq(0)]
 
-        # temporaries for 1st level match
+        # temporaries for lookup
         asid_ok = Signal(reset_less=True)
+        # tags_ok = Signal(reset_less=True)
+
+        vpn3_ok = Signal(reset_less=True)
         vpn2_ok = Signal(reset_less=True)
-        tags_ok = Signal(reset_less=True)
-        vpn2_hit = Signal(reset_less=True)
-        m.d.comb += [tags_ok.eq(tags.valid),
-                     asid_ok.eq(tags.asid == self.lu_asid_i),
-                     vpn2_ok.eq(tags.vpn2 == self.vpn2),
-                     vpn2_hit.eq(tags_ok & asid_ok & vpn2_ok)]
-        # temporaries for 2nd level match
         vpn1_ok = Signal(reset_less=True)
-        tags_2M = Signal(reset_less=True)
         vpn0_ok = Signal(reset_less=True)
+
+        #tags_2M = Signal(reset_less=True)
         vpn0_or_2M = Signal(reset_less=True)
-        m.d.comb += [vpn1_ok.eq(self.vpn1 == tags.vpn1),
-                     tags_2M.eq(tags.is_2M),
-                     vpn0_ok.eq(self.vpn0 == tags.vpn0),
-                     vpn0_or_2M.eq(tags_2M | vpn0_ok)]
-        # TODO temporaries for 3rd level match
+    
+        m.d.comb += [
+                     #compare asid and vpn*
+                     asid_ok.eq(tags.asid == self.lu_asid_i),
+                     vpn3_ok.eq(tags.vpn3 == self.vpn3),
+                     vpn2_ok.eq(tags.vpn2 == self.vpn2),
+                     vpn1_ok.eq(tags.vpn1 == self.vpn1),
+                     vpn0_ok.eq(tags.vpn0 == self.vpn0),
+                     vpn0_or_2M.eq(tags.is_2M | vpn0_ok)
+        ]
+        
         
-        # first level match, this may be a giga page,
-        # check the ASID flags as well
-        with m.If(vpn2_hit):
-            # second level
-            with m.If (tags.is_1G):
+        with m.If(asid_ok & tags.valid):
+            # first level, only vpn3 needs to match
+            with m.If (tags.is_512G & vpn3_ok):
+                m.d.comb += [ self.lu_content_o.eq(content),
+                              self.lu_is_512G_o.eq(1),
+                              self.lu_hit_o.eq(1),
+                            ]
+            # second level , second level vpn2 and vpn3 need to match
+            with m.Elif (tags.is_1G & vpn2_ok & vpn3_ok):
                 m.d.comb += [ self.lu_content_o.eq(content),
                               self.lu_is_1G_o.eq(1),
                               self.lu_hit_o.eq(1),
                             ]
-            # not a giga page hit so check further
+            # not a giga page hit nor a tera page hit so check further
             with m.Elif(vpn1_ok):
                 # this could be a 2 mega page hit or a 4 kB hit
                 # output accordingly
@@ -113,6 +125,7 @@ class TLBContent(Elaboratable):
         with m.Elif(replace_valid):
             m.d.sync += [ # update tag array
                           tags.asid.eq(self.update_i.asid),
+                          tags.vpn3.eq(self.update_i.vpn[27:36]),
                           tags.vpn2.eq(self.update_i.vpn[18:27]),
                           tags.vpn1.eq(self.update_i.vpn[9:18]),
                           tags.vpn0.eq(self.update_i.vpn[0:9]),