More testing and fix Qav + refactor

CHANGELOG.rst

@@ -4,20 +4,24 @@ lib_ethernet change log
 4.0.0
 -----
 
-  * ADDED: Support for running MII sim tests for XS3 architecture
   * ADDED: RMII Ethernet MAC support for XCORE-AI
   * ADDED: Extended sim tests for testing RMII applications
+  * ADDED: Support for running MII sim tests for XS3 architecture
   * ADDED: Support for XCommon CMake build system
   * ADDED: Exit command to RMII RT MAC
   * ADDED: Improved MAC feature documentation
-  * ADDED: Test for SMI
-  * CHANGED: SMI re-write. Single port version now functional
+  * ADDED: Tests for SMI
+  * ADDED: Optional credit limit for Qav shaper
+  * ADDED: Support for running MII sim tests for XS3 architecture
+  * CHANGED: SMI re-write. Single port version now functional and documented
+  * CHANGED: Moved example PHY drivers to lib_board_support
   * REMOVED: Slicekit based examples because hardware is obsolete
   * REMOVED: Support for waf build system
   * REMOVED: Support for XS1 devices
   * RESOLVED: Build warnings even when compile successful
-  * ADDED: Support for running MII sim tests for XS3 architecture
-  * CHANGED: Moved PHY support to separate head and source
+  * RESOLVED: Qav shaper credit overflow causing negative credit on idle
+  * RESOLVED: Packets might not be transmitted for 21 seconds if no transmit
+    activity for 21 seconds (IFG timer)
 
   * Changes to dependencies:
 

lib_ethernet/api/ethernet.h

@@ -9,10 +9,13 @@
 #include "doxygen.h"    // Sphynx Documentation Workarounds
 
 
-#define ETHERNET_ALL_INTERFACES  (-1)
-#define ETHERNET_MAX_PACKET_SIZE (1518) /**< MAX packet size in bytes */
+#define ETHERNET_ALL_INTERFACES     (-1)
+#define ETHERNET_MAX_PACKET_SIZE    (1518) /**< MAX packet size in bytes including src, dst, ether/tags but NOT preamble or CRC*/
+
+#define MACADDR_NUM_BYTES           (6) /**< Number of octets in MAC address */
+
+#define MII_CREDIT_FRACTIONAL_BITS  (16) /** Fractional bits for Qav credit based shaper setting */
 
-#define MACADDR_NUM_BYTES 6
 
 /** Type representing the type of packet from the MAC */
 typedef enum eth_packet_type_t {
@@ -77,7 +80,7 @@ typedef interface ethernet_cfg_if {
    * \param ifnum       The index of the MAC interface to set
    * \param mac_address The six-octet MAC address to set
    */
-  void set_macaddr(size_t ifnum, uint8_t mac_address[MACADDR_NUM_BYTES]);
+  void set_macaddr(size_t ifnum, const uint8_t mac_address[MACADDR_NUM_BYTES]);
 
   /** Gets the source MAC address of the Ethernet MAC
    *
@@ -166,25 +169,36 @@ typedef interface ethernet_cfg_if {
    */
   void get_tile_id_and_timer_value(REFERENCE_PARAM(unsigned, tile_id), REFERENCE_PARAM(unsigned, time_on_tile));
 
-  /** Set the high-priority TX queue's credit based shaper idle slope.
+  /** Set the high-priority TX queue's credit based shaper idle slope value.
+   *  See also set_egress_qav_idle_slope_bps() where the argument is bits per second.
    *  This function is only available in the 10/100 Mb/s real-time and 10/100/1000 Mb/s MACs.
    *
-   *  \param ifnum   The index of the MAC interface to set the slope
+   *  \param ifnum   The index of the MAC interface to set the slope (always 0)
    *  \param slope   The slope value in bits per 100 MHz ref timer tick in MII_CREDIT_FRACTIONAL_BITS Q format.
    * 
-   *  To convert from bits-per-second to the MII_CREDIT_FRACTIONAL_BITS format for the parameter 'slope', the
-   *  following helper function may be used:
    * 
-   *  unsigned calc_idle_slope(unsigned bits_per_second)
-   *  {
-   *      unsigned long long slope = ((unsigned long long) bits_per_second) << (MII_CREDIT_FRACTIONAL_BITS);
-   *      slope = slope / XS1_TIMER_HZ; // bits that should be sent per ref timer tick
+   */
+  void set_egress_qav_idle_slope(size_t ifnum, unsigned slope);
+
+  /** Set the high-priority TX queue's credit based shaper idle slope in bits per second.
+   *  This function is only available in the 10/100 Mb/s real-time and 10/100/1000 Mb/s MACs.
+   *
+   *  \param ifnum   The index of the MAC interface to set the slope (always 0)
+   *  \param slope   The maximum number of bits per second to be set
    * 
-   *      return (unsigned) slope;
-   *  }
    * 
    */
-  void set_egress_qav_idle_slope(size_t ifnum, unsigned slope);
+  void set_egress_qav_idle_slope_bps(size_t ifnum, unsigned bits_per_second);
+
+
+  /** Sets the the high-priority TX queue's  Qav credit limit in units of frame size bytes
+   *
+   *  \param ifnum         The index of the MAC interface to set the slope (always 0)
+   *  \param limit_bytes   The credit limit in units of payload size in bytes to set as a credit limit,
+   *                       not including preamble, CRC and IFG. Set to 0 for no limit (default)
+   *
+   */
+  void set_egress_qav_credit_limit(size_t ifnum, int payload_limit_bytes);
 
   /** Set the ingress latency to correct for the offset between the timestamp
    *  measurement plane relative to the reference plane. See 802.1AS 8.4.3.
@@ -433,8 +447,8 @@ inline void ethernet_send_hp_packet(streaming_chanend_t c_tx_hp,
  *  on the egress MAC port.
  */
 enum ethernet_enable_shaper_t {
-  ETHERNET_ENABLE_SHAPER, /**< Enable the credit based shaper */
-  ETHERNET_DISABLE_SHAPER /**< Disable the credit based shaper */
+  ETHERNET_DISABLE_SHAPER = 0, /**< Disable the credit based shaper */
+  ETHERNET_ENABLE_SHAPER       /**< Enable the credit based shaper */
 };
 
 /** Structure representing the port and clock resources required by RGMII

lib_ethernet/lib_build_info.cmake

@@ -15,7 +15,7 @@ set(LIB_COMPILER_FLAGS      -g
 
 set(LIB_OPTIONAL_HEADERS    ethernet_conf.h)
 
-set(LIB_COMPILER_FLAGS_mii_master.xc            ${LIB_COMPILER_FLAGS} -O3 -fschedule -g0 -mno-dual-issue)
+set(LIB_COMPILER_FLAGS_mii_master.xc            ${LIB_COMPILER_FLAGS} -O3 -fschedule -g -mno-dual-issue)
 set(LIB_COMPILER_FLAGS_macaddr_filter.xc        ${LIB_COMPILER_FLAGS} -Wno-reinterpret-alignment)
 set(LIB_COMPILER_FLAGS_mii.xc                   ${LIB_COMPILER_FLAGS} -Wno-cast-align -Wno-unusual-code)
 set(LIB_COMPILER_FLAGS_mii_ethernet_mac.xc      ${LIB_COMPILER_FLAGS} -Wno-cast-align -Wno-unusual-code)

lib_ethernet/module_build_info

@@ -14,7 +14,7 @@ OPTIONAL_HEADERS += ethernet_conf.h
 
 MODULE_XCC_FLAGS = $(XCC_FLAGS) -g -O3 -mno-dual-issue
 
-XCC_FLAGS_mii_master.xc = $(XCC_FLAGS) -O3 -fschedule -g0 -mno-dual-issue
+XCC_FLAGS_mii_master.xc = $(XCC_FLAGS) -O3 -fschedule -g -mno-dual-issue
 XCC_FLAGS_macaddr_filter.xc = $(MODULE_XCC_FLAGS) -Wno-reinterpret-alignment
 XCC_FLAGS_mii.xc = $(MODULE_XCC_FLAGS) -Wno-cast-align -Wno-unusual-code
 XCC_FLAGS_mii_ethernet_mac.xc = $(MODULE_XCC_FLAGS) -Wno-cast-align -Wno-unusual-code

lib_ethernet/src/mii_ethernet_mac.xc

@@ -160,7 +160,7 @@ static void mii_ethernet_aux(client mii_if i_mii,
         memcpy(r_mac_address, mac_address, sizeof mac_address);
         break;
 
-      case i_cfg[int i].set_macaddr(size_t ifnum, uint8_t r_mac_address[MACADDR_NUM_BYTES]):
+      case i_cfg[int i].set_macaddr(size_t ifnum, const uint8_t r_mac_address[MACADDR_NUM_BYTES]):
         memcpy(mac_address, r_mac_address, sizeof r_mac_address);
         break;
 
@@ -221,6 +221,16 @@ static void mii_ethernet_aux(client mii_if i_mii,
         fail("Shaper not supported in standard MII Ethernet MAC");
         break;
 
+      case i_cfg[int i].set_egress_qav_idle_slope_bps(size_t ifnum, unsigned bits_per_second): {
+        fail("Shaper not supported in standard MII Ethernet MAC");
+        break;
+      }
+
+      case i_cfg[int i].set_egress_qav_credit_limit(size_t ifnum, int payload_limit_bytes): {
+        fail("Shaper not supported in standard MII Ethernet MAC");
+        break;
+      }
+
       case i_cfg[int i].set_ingress_timestamp_latency(size_t ifnum, ethernet_speed_t speed, unsigned value): {
         fail("Timestamp correction not supported in standard MII Ethernet MAC");
         break;

lib_ethernet/src/mii_ethernet_rt_mac.xc

@@ -15,6 +15,7 @@
 #include "print.h"
 #include "server_state.h"
 #include "rmii_rx_pins_exit.h"
+#include "shaper.h"
 
 
 static inline unsigned int get_tile_id_from_chanend(chanend c) {
@@ -322,7 +323,7 @@ unsafe void mii_ethernet_server(mii_mempool_t rx_mem,
       memcpy(r_mac_address, mac_address, sizeof mac_address);
       break;
 
-    case i_cfg[int i].set_macaddr(size_t ifnum, uint8_t r_mac_address[MACADDR_NUM_BYTES]):
+    case i_cfg[int i].set_macaddr(size_t ifnum, const uint8_t r_mac_address[MACADDR_NUM_BYTES]):
       memcpy(mac_address, r_mac_address, sizeof r_mac_address);
       break;
 
@@ -404,11 +405,21 @@ unsafe void mii_ethernet_server(mii_mempool_t rx_mem,
       break;
     }
 
+    case i_cfg[int i].set_egress_qav_idle_slope_bps(size_t ifnum, unsigned bits_per_second): {
+      set_qav_idle_slope(p_port_state, bits_per_second);
+      break;
+    }
+
+    case i_cfg[int i].set_egress_qav_credit_limit(size_t ifnum, int payload_limit_bytes): {
+      set_qav_credit_limit(p_port_state, payload_limit_bytes);
+      break;
+    }
+
     case i_cfg[int i].set_ingress_timestamp_latency(size_t ifnum, ethernet_speed_t speed, unsigned value): {
       if (speed < 0 || speed >= NUM_ETHERNET_SPEEDS) {
         fail("Invalid Ethernet speed, must be a valid ethernet_speed_t enum value");
       }
-      p_port_state->ingress_ts_latency[speed] = value / 10;
+      p_port_state->ingress_ts_latency[speed] = value / 10; // div by 10 to get to timer ticks from nanonseconds 
       break;
     }
 

lib_ethernet/src/mii_master.xc

@@ -13,6 +13,7 @@
 #include "mii_common_lld.h"
 #include "string.h"
 #include "check_ifg_wait.h"
+#include "shaper.h"
 
 #define QUOTEAUX(x) #x
 #define QUOTE(x) QUOTEAUX(x)
@@ -471,9 +472,9 @@ unsafe void mii_master_tx_pins(mii_mempool_t tx_mem_lp,
                                out buffered port:32 p_mii_txd,
                                volatile ethernet_port_state_t * unsafe p_port_state)
 {
-  int credit = 0; // No. of bits allowed to send
-  int credit_time;
-  // Need one timer to be able to read at any time for the shaper
+  qav_state_t qav_state = {0, 0, 0}; // Set times and credit to zero so it can tx first frame
+
+  // Need a timer to be able to read at any time for the shaper
   timer credit_tmr;
   // And a second timer to be enforcing the IFG gap
   hwtimer_t ifg_tmr;
@@ -485,7 +486,8 @@ unsafe void mii_master_tx_pins(mii_mempool_t tx_mem_lp,
     enable_shaper = 0;
 
   if (ETHERNET_SUPPORT_HP_QUEUES && enable_shaper) {
-    credit_tmr :> credit_time;
+    credit_tmr :> qav_state.current_time;
+    qav_state.prev_time = qav_state.current_time;
   }
 
   ifg_tmr :> ifg_time;
@@ -496,27 +498,15 @@ unsafe void mii_master_tx_pins(mii_mempool_t tx_mem_lp,
     mii_ts_queue_t *p_ts_queue = null;
     mii_mempool_t tx_mem = tx_mem_hp;
 
-    if (ETHERNET_SUPPORT_HP_QUEUES)
+    if (ETHERNET_SUPPORT_HP_QUEUES) {
       buf = mii_get_next_buf(packets_hp);
+    }
 
     if (enable_shaper) {
-      int prev_credit_time = credit_time;
-      credit_tmr :> credit_time;
-
-      int elapsed = credit_time - prev_credit_time;
-      credit += elapsed * p_port_state->qav_idle_slope; // add bit budget since last transmission to credit. ticks * bits/tick = bits
-
-      if (buf) {
-        if (credit < 0) {
-          buf = 0; // if out of credit drop this HP packet
-        }
-      }
-      else {
-        if (credit > 0)
-          credit = 0;
-      }
+      credit_tmr :> qav_state.current_time;
+      buf = shaper_do_idle_slope(buf, &qav_state, p_port_state);
     }
-
+    
     if (!buf) {
       buf = mii_get_next_buf(packets_lp);
       p_ts_queue = &ts_queue;
@@ -530,19 +520,15 @@ unsafe void mii_master_tx_pins(mii_mempool_t tx_mem_lp,
 
     unsigned time = mii_transmit_packet(tx_mem, buf, p_mii_txd, ifg_tmr, ifg_time, eof_time);
 
-    eof_time = ifg_time;
     // Setup the hardware timer to enforce the IFG
+    eof_time = ifg_time;
     ifg_time += MII_ETHERNET_IFS_AS_REF_CLOCK_COUNT;
     ifg_time += (buf->length & 0x3) * 8;
 
+    // Calculate the send slope (decrement credit) if enabled and was HP
     const int packet_is_high_priority = (p_ts_queue == null);
     if (enable_shaper && packet_is_high_priority) {
-      const int preamble_bytes = 8;
-      const int ifg_bytes = 96/8;
-      const int crc_bytes = 4;
-      int len = buf->length + preamble_bytes + ifg_bytes + crc_bytes;
-      // decrease credit by no. of bits transmitted
-      credit = credit - (len << (MII_CREDIT_FRACTIONAL_BITS+3)); // MII_CREDIT_FRACTIONAL_BITS+3 to convert from bytes to bits
+      shaper_do_send_slope(buf->length, &qav_state);
     }
 
     if (mii_get_and_dec_transmit_count(buf) == 0) {
@@ -559,6 +545,6 @@ unsafe void mii_master_tx_pins(mii_mempool_t tx_mem_lp,
         mii_free_current(packets_hp);
       }
     }
-  }
+  } // while(1)
 }