Merge pull request #238 from alexandergall/loop-unroll

Apply partial loop-unrolling to avoid trace aborts

src/apps/intel/intel10g.lua

@@ -173,14 +173,27 @@ end
 local txdesc_flags = bits{ifcs=25, dext=29, dtyp0=20, dtyp1=21}
 local txdesc_flags_last = bits({eop=24}, txdesc_flags)
 
+local function transmit_aux (self, p, i, niovecs)
+   local iov = p.iovecs[i]
+   local flags = (i + 1 < niovecs) and txdesc_flags or txdesc_flags_last
+   self.txdesc[self.tdt].address = iov.buffer.physical + iov.offset
+   self.txdesc[self.tdt].options = bor(iov.length, flags, lshift(p.length+0ULL, 46))
+   self.txpackets[self.tdt] = packet_ref(p)
+   self.tdt = band(self.tdt + 1, num_descriptors - 1)
+end
+
 function M_sf:transmit (p)
-   for i = 0, p.niovecs - 1 do
-      local iov = p.iovecs[i]
-      local flags = (i + 1 < p.niovecs) and txdesc_flags or txdesc_flags_last
-      self.txdesc[self.tdt].address = iov.buffer.physical + iov.offset
-      self.txdesc[self.tdt].options = bor(iov.length, flags, lshift(p.length+0ULL, 46))
-      self.txpackets[self.tdt] = packet_ref(p)
-      self.tdt = band(self.tdt + 1, num_descriptors - 1)
+   local niovecs = p.niovecs
+   if niovecs > 0 then
+      transmit_aux(self, p, 0, niovecs)
+   end
+   if niovecs > 1 then
+      transmit_aux(self, p, 1, niovecs)
+   end
+   if niovecs > 2 then
+      for i = 2, niovecs - 1 do
+	 transmit_aux(self, p, i, niovecs)
+      end
    end
 end
 
@@ -189,10 +202,12 @@ function M_sf:sync_transmit ()
    self.tdh = self.r.TDH()
    C.full_memory_barrier()
    -- Release processed buffers
-   while old_tdh ~= self.tdh do
-      packet.deref(self.txpackets[old_tdh])
-      self.txpackets[old_tdh] = nil
-      old_tdh = band(old_tdh + 1, num_descriptors - 1)
+   if old_tdh ~= self.tdh then
+      while old_tdh ~= self.tdh do
+	 packet.deref(self.txpackets[old_tdh])
+	 self.txpackets[old_tdh] = nil
+	 old_tdh = band(old_tdh + 1, num_descriptors - 1)
+      end
    end
    self.r.TDT(self.tdt)
 end
@@ -205,17 +220,25 @@ end
 
 --- See datasheet section 7.1 "Inline Functions -- Receive Functionality."
 
+local function receive_aux(self, p)
+   local wb = self.rxdesc[self.rxnext].wb
+   if band(wb.xstatus_xerror, 1) == 1 then -- Descriptor Done
+      local b = self.rxbuffers[self.rxnext]
+      packet.add_iovec(p, b, wb.pkt_len)
+      self.rxnext = band(self.rxnext + 1, num_descriptors - 1)
+   end
+   return band(wb.xstatus_xerror, 2) == 2  -- End Of Packet
+end
+
 function M_sf:receive ()
    assert(self.rdh ~= self.rxnext)
    local p = packet.allocate()
-   repeat
-      local wb = self.rxdesc[self.rxnext].wb
-      if band(wb.xstatus_xerror, 1) == 1 then -- Descriptor Done
-         local b = self.rxbuffers[self.rxnext]
-         packet.add_iovec(p, b, wb.pkt_len)
-         self.rxnext = band(self.rxnext + 1, num_descriptors - 1)
+   if not receive_aux(self, p) then
+      if not receive_aux(self, p) then
+	 repeat
+	 until receive_aux(self, p)
       end
-   until band(wb.xstatus_xerror, 2) == 2  -- End Of Packet
+   end
    return p
 end
 

src/core/packet.lua

@@ -199,9 +199,23 @@ function tenure (p)
 end
 
 -- Free a packet and all of its buffers.
+
+local function free_aux(p, i)
+   buffer.free(p.iovecs[i].buffer)
+end
+
 function free (p)
-   for i = 0, p.niovecs-1 do
-      buffer.free(p.iovecs[i].buffer)
+   local niovecs = p.niovecs
+   if niovecs > 0 then
+      free_aux(p, 0)
+   end
+   if niovecs > 1 then
+      free_aux(p, 1)
+   end
+   if niovecs > 2 then
+      for i = 2, p.niovecs-1 do
+	 free_aux(p, i)
+      end
    end
    p.length         = 0
    p.niovecs        = 0

src/lib/hardware/register.lua

@@ -55,7 +55,7 @@ function Register:noop () end
 ---     reg()      <=> reg:read()
 ---     reg(value) <=> reg:write(value)
 function Register:__call (value)
-   if value then return self:write(value) else return self:read() end
+   if value then return (self:write(value)) else return (self:read()) end
 end
 
 --- Registers print as `$NAME:$HEXVALUE` to make debugging easy.

src/lib/protocol/header.lua

@@ -144,11 +144,11 @@ end
 -- Instance methods
 
 function header:header ()
-   return self._header[0][0]
+   return (self._header[0][0])
 end
 
 function header:sizeof ()
-   return ffi.sizeof(self._header_type)
+   return (ffi.sizeof(self._header_type))
 end
 
 -- default equality method, can be overriden in the ancestors