Network: Improve error handling when unable to allocate blocks.

- Refactor init code to allow external code to reset TX or RX state machines.
- Update the TX routines to return true on sucessfull allocation, and false otherwise.
- When allocation fails, drain the ramining passthrough buffer to ensure that the NCSI block is not locked up.

1 files changed, 45 insertions, 21 deletions

diff --git a/libs/Network/tx.c b/libs/Network/tx.c
index d619bf4..a1cd30e 100644
--- a/libs/Network/tx.c
+++ b/libs/Network/tx.c
@@ -43,6 +43,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 #include <APE_APE.h>
+#include <APE_SHM.h>
 #include <APE_TX_PORT0.h>
 #include <Ethernet.h>
 #include <Network.h>
@@ -52,6 +53,7 @@
 #include <endian.h>
 #include <stdio.h>
 #else
+#include <printf.h>
 /* ARM */
 static inline uint32_t be32toh(uint32_t be32)
 {
@@ -75,9 +77,6 @@ uint32_t Network_TX_numBlocksNeeded(uint32_t frame_size)
         blocks += DIVIDE_RND_UP(frame_size, ADDITIONAL_FRAME_MAX);
     }
 
-#ifdef CXX_SIMULATOR
-    printf("%d blocks needed for packet with frame size %d\n", blocks, frame_size);
-#endif
     return blocks;
 }
 
@@ -101,16 +100,11 @@ int32_t __attribute__((noinline)) Network_TX_allocateBlock(NetworkPort_t *port)
     if (APE_TX_TO_NET_BUFFER_ALLOCATOR_STATE_ALLOCATION_OK != status.bits.State)
     {
         block = -1;
-#if CXX_SIMULATOR
         printf("Error: Failed to allocate TX block.\n");
-#endif
     }
     else
     {
         block = status.bits.Index;
-#if CXX_SIMULATOR
-        printf("Allocated TX block %d\n", block);
-#endif
     }
 
     return block;
@@ -233,18 +227,17 @@ static uint32_t inline Network_TX_initAdditionalBlock(RegTX_PORTOut_t *block, in
     return control.bits.payload_length;
 }
 
-static inline void Network_TX_transmitPacket_internal(uint8_t *packet, uint32_t length, bool big_endian, NetworkPort_t *port)
+static inline bool Network_TX_transmitPacket_internal(uint8_t *packet, uint32_t length, bool big_endian, NetworkPort_t *port)
 {
     if (!length)
     {
-        return;
+        return false;
     }
 
     uint32_t *packet_32 = (uint32_t *)packet;
     uint32_t consumed = 0;
     uint32_t blocks = Network_TX_numBlocksNeeded(length);
     int total_blocks = blocks;
-    ;
 
     // First block
     int32_t tail;
@@ -252,7 +245,7 @@ static inline void Network_TX_transmitPacket_internal(uint8_t *packet, uint32_t
     if (first <= 0)
     {
         // Error
-        return;
+        return false;
     }
     int32_t next_block = -1;
     if (blocks > 1)
@@ -287,16 +280,18 @@ static inline void Network_TX_transmitPacket_internal(uint8_t *packet, uint32_t
     doorbell.bits.Length = total_blocks;
 
     *((RegAPETxToNetDoorbell_t *)port->tx_doorbell) = doorbell;
+
+    return true;
 }
 
-void Network_TX_transmitBePacket(uint8_t *packet, uint32_t length, NetworkPort_t *port)
+bool Network_TX_transmitBePacket(uint8_t *packet, uint32_t length, NetworkPort_t *port)
 {
-    Network_TX_transmitPacket_internal(packet, length, true, port);
+    return Network_TX_transmitPacket_internal(packet, length, true, port);
 }
 
-void Network_TX_transmitLePacket(uint8_t *packet, uint32_t length, NetworkPort_t *port)
+bool Network_TX_transmitLePacket(uint8_t *packet, uint32_t length, NetworkPort_t *port)
 {
-    Network_TX_transmitPacket_internal(packet, length, false, port);
+    return Network_TX_transmitPacket_internal(packet, length, false, port);
 }
 
 static uint32_t inline Network_TX_initFirstPassthroughBlock(RegTX_PORTOut_t *block, uint32_t length, int32_t blocks, int32_t next_block)
@@ -396,38 +391,65 @@ static uint32_t inline Network_TX_initAdditionalPassthroughBlock(RegTX_PORTOut_t
     return control.bits.payload_length;
 }
 
-void Network_TX_transmitPassthroughPacket(uint32_t length, NetworkPort_t *port)
+static void drainPassthroughBytes(uint32_t bytes)
 {
-    if (!length)
+    printf("Dropping %d bytes\n", bytes);
+    // Drain any passthrough bytes to ensure that the NCSI input buffers are not locked up.
+    int num_words = DIVIDE_RND_UP(bytes, sizeof(uint32_t)) + 1; // +1 for FCS word.
+    for (int i = 0; i < num_words; i++)
     {
-        return;
+        uint32_t word = APE_PERI.BmcToNcReadBuffer.r32;
+        (void)word;
     }
+}
 
+bool Network_TX_transmitPassthroughPacket(uint32_t length, NetworkPort_t *port)
+{
+    if (!length)
+    {
+        return false;
+    }
     // Drop the FCS word. It will be generated by hardware.
     length -= 4;
 
     int32_t tail;
     int32_t first = tail = Network_TX_allocateBlock(port);
+    if(first < 0)
+    {
+        // Unable to allocate block.
+        drainPassthroughBytes(length);
+        return false;
+    }
     int32_t next_block = -1;
     uint32_t blocks = Network_TX_numBlocksNeeded(length);
     int total_blocks = blocks;
-    ;
+
+    printf("Sending passhrough packet to Net. First block: %d (%d total).\n", first, blocks);
 
     if (blocks > 1)
     {
         next_block = Network_TX_allocateBlock(port);
+        if(next_block < 0)
+        {
+            return false;
+        }
     }
     RegTX_PORTOut_t *block = (RegTX_PORTOut_t *)&port->tx_port->Out[TX_PORT_OUT_ALL_BLOCK_WORDS * first];
 
     length -= Network_TX_initFirstPassthroughBlock(block, length, blocks, next_block);
     blocks -= 1;
+
     while (blocks--)
     {
-
         block = (RegTX_PORTOut_t *)&port->tx_port->Out[TX_PORT_OUT_ALL_BLOCK_WORDS * next_block];
         if (blocks)
         {
             next_block = Network_TX_allocateBlock(port);
+            if(next_block < 0)
+            {
+                drainPassthroughBytes(length);
+                return false;
+            }
             length -= Network_TX_initAdditionalPassthroughBlock(block, next_block, length);
         }
         else
@@ -449,4 +471,6 @@ void Network_TX_transmitPassthroughPacket(uint32_t length, NetworkPort_t *port)
     // Read last RX word (FCS) to clear the buffer
     uint32_t data = APE_PERI.BmcToNcReadBuffer.r32;
     (void)data;
+
+    return true;
 }