intel_mp: add queue enable counters, fix rxdrop counter

Two counters are added for each queue called "q<i>_<rx|tx>_enabled",
which is set to one if the corresponding queue is enabled and zero
otherwise.  This helps consumers of the statistics to determine which
of the per-queue counters contain valid data.

Queues are enabled implicitly when an instance of the driver is
initialized but the counters are maintained by the master process
only.  The only way for the master to detect the state of a queue is
by an explicite check in sync_stats().

For each process, two new counters txq and rxq are created which hold
the number of the transmit and receive queues for which the driver was
configured.

For the 82599, receive drop counters are maintained per rx queue.  The
total rx drop counter must be derived from the per-queue counters.
This commit assumes that each enabled receive queue uses its "natural"
statistics register.

src/apps/intel_mp/intel_mp.lua

@@ -61,6 +61,7 @@ reg['82599ES'] = {
    array = [[
 ALLRXDCTL   0x01028 +0x40*0..63     RW Receive Descriptor Control
 ALLRXDCTL   0x0D028 +0x40*64..127   RW Receive Descriptor Control
+ALLTXDCTL   0x06028 +0x40*0..127    RW Transmit Descriptor Control
 DAQF        0x0E200 +0x04*0..127    RW Destination Address Queue Filter
 FTQF        0x0E600 +0x04*0..127    RW Five Tuple Queue Filter
 ETQF        0x05128 +0x04*0..7      RW EType Queue Filter
@@ -187,7 +188,6 @@ TDWBAH      0x0603C +0x40*0..127    RW Tx Descriptor Completion Write Back Addre
 }
 reg['1000BaseX'] = {
    array = [[
-ALLRXDCTL   0x0c028 +0x40*0..7      RW Re Descriptor Control Queue
 RAL64       0x05400 +0x08*0..15     RW64 Receive Address Low
 RAL         0x05400 +0x08*0..15     RW Receive Address Low
 RAH         0x05404 +0x08*0..15     RW Receive Address High
@@ -245,6 +245,8 @@ TXCTL  0xe014 +0x40*0..7            RW Tx DCA CTRL Register Queue
 }
 reg.i210 = {
    array = [[
+ALLRXDCTL   0x0c028 +0x40*0..3      RW Re Descriptor Control Queue
+ALLTXDCTL   0x0e028 +0x40*0..3      RW Tx Descriptor Control Queue
 RQDPC       0x0C030 +0x40*0..3      RC Receive Queue Drop Packet Count
 TQDPC       0x0E030 +0x40*0..3      RC Transmit Queue Drop Packet Count
 PQGPRC      0x10010 +0x100*0..3     RC Per Queue Good Packets Received Count
@@ -261,6 +263,8 @@ EEC       0x12010 -            RW EEPROM-Mode Control Register
 }
 reg.i350 = {
    array = [[
+ALLRXDCTL   0x0c028 +0x40*0..7      RW Re Descriptor Control Queue
+ALLTXDCTL   0x0e028 +0x40*0..7      RW Tx Descriptor Control Queue
 RQDPC       0x0C030 +0x40*0..7      RCR Receive Queue Drop Packet Count
 TQDPC       0x0E030 +0x40*0..7      RCR Transmit Queue Drop Packet Count
 PQGPRC      0x10010 +0x100*0..7     RCR Per Queue Good Packets Received Count
@@ -372,7 +376,9 @@ function Intel:new (conf)
    -- Initialize per app statistics
    self.shm = {
       mtu    = {counter, self.mtu},
-      txdrop = {counter}
+      txdrop = {counter},
+      txq    = {counter, self.txq},
+      rxq    = {counter, self.rxq}
    }
 
    -- Figure out if we are supposed to collect device statistics
@@ -822,6 +828,15 @@ function Intel:sync_stats ()
       local name, register = self.queue_stats[idx], self.queue_stats[idx+1]
       set(stats[name], register())
    end
+   local enable = lshift(1, 25)
+   for i = 0, self.max_q-1 do
+      if band(self.r.ALLRXDCTL[i](), enable) > 0 then
+         set(stats[self.queue_stats_names.rx_enabled[i]], 1)
+      end
+      if band(self.r.ALLTXDCTL[i](), enable) > 0 then
+         set(stats[self.queue_stats_names.tx_enabled[i]], 1)
+      end
+   end
 end
 
 -- set MAC address (4.6.10.1.4)
@@ -1145,27 +1160,42 @@ function Intel1g:rxdmapackets ()
    return self.r.RPTHC()
 end
 
-function Intel1g:init_queue_stats (frame)
-   local perqregs = {
-      rxdrops = "RQDPC",
-      txdrops = "TQDPC",
-      rxpackets = "PQGPRC",
-      txpackets = "PQGPTC",
-      rxbytes = "PQGORC",
-      txbytes = "PQGOTC",
-      rxmcast = "PQMPRC"
-   }
+local function init_queue_stats (self, frame, perqregs)
    self.queue_stats = {}
+   self.queue_stats_names = {}
+
+   local function add_q_counter (qid, cname)
+      local name = "q" .. qid .. "_" .. cname
+      frame[name] = { counter, 0 }
+      local t = self.queue_stats_names
+      if not t[cname] then
+         t[cname] = {}
+      end
+      t[cname][qid] = name
+      return name
+   end
+
    for i=0,self.max_q-1 do
+      add_q_counter(i, "rx_enabled")
+      add_q_counter(i, "tx_enabled")
       for k,v in pairs(perqregs) do
-         local name = "q" .. i .. "_" .. k
-         table.insert(self.queue_stats, name)
+         table.insert(self.queue_stats, add_q_counter(i, k))
          table.insert(self.queue_stats, self.r[v][i])
-         frame[name] = {counter}
       end
    end
 end
 
+function Intel1g:init_queue_stats (frame)
+   init_queue_stats(self, frame,
+                    { rxdrops = "RQDPC",
+                      txdrops = "TQDPC",
+                      rxpackets = "PQGPRC",
+                      txpackets = "PQGPTC",
+                      rxbytes = "PQGORC",
+                      txbytes = "PQGOTC",
+                      rxmcast = "PQMPRC" })
+end
+
 function Intel1g:get_rxstats ()
    assert(self.rxq, "cannot retrieve rxstats without rxq")
    local frame = shm.open_frame("pci/"..self.pciaddress)
@@ -1245,7 +1275,21 @@ function Intel82599:promisc ()
    return band(self.r.FCTRL(), lshift(1, 9)) ~= 0ULL
 end
 function Intel82599:rxbytes  () return self.r.GORC64()   end
-function Intel82599:rxdrop   () return self.r.QPRDC[0]() end
+function Intel82599:rxdrop   ()
+   -- Accumulate the per-queue rx drop counters (there is no global
+   -- drop counter).  This assumes that each queue uses its natural
+   -- counter, which is not guaranteed because the statistics register
+   -- can be chosen arbitrarily (via the rxcounter configuration
+   -- option)
+   local read, stats = counter.read, self.stats
+   local rxdrop = 0
+   for i = 0, self.max_q -1 do
+      if read(stats[self.queue_stats_names.rx_enabled[i]]) == 1 then
+         rxdrop = rxdrop + read(stats[self.queue_stats_names.rxdrops[i]])
+      end
+   end
+   return rxdrop
+end
 function Intel82599:rxerrors ()
    return self.r.CRCERRS() + self.r.ILLERRC() + self.r.ERRBC() +
       self.r.RUC() + self.r.RFC() + self.r.ROC() + self.r.RJC()
@@ -1258,22 +1302,12 @@ function Intel82599:rxdmapackets ()
 end
 
 function Intel82599:init_queue_stats (frame)
-   local perqregs = {
-      rxdrops = "QPRDC",
-      rxpackets = "QPRC",
-      txpackets = "QPTC",
-      rxbytes = "QBRC64",
-      txbytes = "QBTC64",
-   }
-   self.queue_stats = {}
-   for i=0,15 do
-      for k,v in pairs(perqregs) do
-         local name = "q" .. i .. "_" .. k
-         table.insert(self.queue_stats, name)
-         table.insert(self.queue_stats, self.r[v][i])
-         frame[name] = {counter}
-      end
-   end
+   init_queue_stats(self, frame,
+                    { rxdrops = "QPRDC",
+                      rxpackets = "QPRC",
+                      txpackets = "QPTC",
+                      rxbytes = "QBRC64",
+                      txbytes = "QBTC64" })
 end
 
 function Intel82599:init ()