eepro100: Restructure code (new function tx_command)

Handling of transmit commands is rather complex,
so about 80 lines of code were moved from function
action_command to the new function tx_command.

The two new values "tx" and "cb_address" in the
eepro100 status structure made this possible without
passing too many parameters.

In addition, the moved code was cleaned a little bit:
old comments marked with //~ were removed, C++ style
comments were replaced by C style comments, C++ like
variable declarations after code were reordered.

Simplified mode is still broken. Nor did I fix
endianess issues. Both problems will be fixed in
additional patches (which need this one).

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/eepro100.c

@@ -212,6 +212,11 @@ typedef struct {
     uint32_t ru_offset;         /* RU address offset */
     uint32_t statsaddr;         /* pointer to eepro100_stats_t */
 
+    /* Temporary status information (no need to save these values),
+     * used while processing CU commands. */
+    eepro100_tx_t tx;           /* transmit buffer descriptor */
+    uint32_t cb_address;        /* = cu_base + cu_offset */
+
     /* Statistical counters. Also used for wake-up packet (i82559). */
     eepro100_stats_t statistics;
 
@@ -760,17 +765,100 @@ static void dump_statistics(EEPRO100State * s)
     //~ missing("CU dump statistical counters");
 }
 
+static void tx_command(EEPRO100State *s)
+{
+    uint32_t tbd_array = le32_to_cpu(s->tx.tx_desc_addr);
+    uint16_t tcb_bytes = (le16_to_cpu(s->tx.tcb_bytes) & 0x3fff);
+    /* Sends larger than MAX_ETH_FRAME_SIZE are allowed, up to 2600 bytes. */
+    uint8_t buf[2600];
+    uint16_t size = 0;
+    uint32_t tbd_address = s->cb_address + 0x10;
+    TRACE(RXTX, logout
+        ("transmit, TBD array address 0x%08x, TCB byte count 0x%04x, TBD count %u\n",
+         tbd_array, tcb_bytes, s->tx.tbd_count));
+
+    if (tcb_bytes > 2600) {
+        logout("TCB byte count too large, using 2600\n");
+        tcb_bytes = 2600;
+    }
+    if (!((tcb_bytes > 0) || (tbd_array != 0xffffffff))) {
+        logout
+            ("illegal values of TBD array address and TCB byte count!\n");
+    }
+    assert(tcb_bytes <= sizeof(buf));
+    while (size < tcb_bytes) {
+        uint32_t tx_buffer_address = ldl_phys(tbd_address);
+        uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
+        //~ uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
+        tbd_address += 8;
+        TRACE(RXTX, logout
+            ("TBD (simplified mode): buffer address 0x%08x, size 0x%04x\n",
+             tx_buffer_address, tx_buffer_size));
+        tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
+        cpu_physical_memory_read(tx_buffer_address, &buf[size],
+                                 tx_buffer_size);
+        size += tx_buffer_size;
+    }
+    if (tbd_array == 0xffffffff) {
+        /* Simplified mode. Was already handled by code above. */
+    } else {
+        /* Flexible mode. */
+        uint8_t tbd_count = 0;
+        if (s->has_extended_tcb_support && !(s->configuration[6] & BIT(4))) {
+            /* Extended Flexible TCB. */
+            for (; tbd_count < 2; tbd_count++) {
+                uint32_t tx_buffer_address = ldl_phys(tbd_address);
+                uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
+                uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
+                tbd_address += 8;
+                TRACE(RXTX, logout
+                    ("TBD (extended flexible mode): buffer address 0x%08x, size 0x%04x\n",
+                     tx_buffer_address, tx_buffer_size));
+                tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
+                cpu_physical_memory_read(tx_buffer_address, &buf[size],
+                                         tx_buffer_size);
+                size += tx_buffer_size;
+                if (tx_buffer_el & 1) {
+                    break;
+                }
+            }
+        }
+        tbd_address = tbd_array;
+        for (; tbd_count < s->tx.tbd_count; tbd_count++) {
+            uint32_t tx_buffer_address = ldl_phys(tbd_address);
+            uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
+            uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
+            tbd_address += 8;
+            TRACE(RXTX, logout
+                ("TBD (flexible mode): buffer address 0x%08x, size 0x%04x\n",
+                 tx_buffer_address, tx_buffer_size));
+            tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
+            cpu_physical_memory_read(tx_buffer_address, &buf[size],
+                                     tx_buffer_size);
+            size += tx_buffer_size;
+            if (tx_buffer_el & 1) {
+                break;
+            }
+        }
+    }
+    TRACE(RXTX, logout("%p sending frame, len=%d,%s\n", s, size, nic_dump(buf, size)));
+    qemu_send_packet(&s->nic->nc, buf, size);
+    s->statistics.tx_good_frames++;
+    /* Transmit with bad status would raise an CX/TNO interrupt.
+     * (82557 only). Emulation never has bad status. */
+    //~ eepro100_cx_interrupt(s);
+}
+
 static void action_command(EEPRO100State *s)
 {
     for (;;) {
-        uint32_t cb_address = s->cu_base + s->cu_offset;
+        s->cb_address = s->cu_base + s->cu_offset;
-        eepro100_tx_t tx;
+        cpu_physical_memory_read(s->cb_address, (uint8_t *)&s->tx, sizeof(s->tx));
-        cpu_physical_memory_read(cb_address, (uint8_t *) & tx, sizeof(tx));
+        uint16_t status = le16_to_cpu(s->tx.status);
-        uint16_t status = le16_to_cpu(tx.status);
+        uint16_t command = le16_to_cpu(s->tx.command);
-        uint16_t command = le16_to_cpu(tx.command);
         logout
             ("val=0x%02x (cu start), status=0x%04x, command=0x%04x, link=0x%08x\n",
-             val, status, command, tx.link);
+             val, status, command, s->tx.link);
         bool bit_el = ((command & 0x8000) != 0);
         bool bit_s = ((command & 0x4000) != 0);
         bool bit_i = ((command & 0x2000) != 0);
@@ -778,17 +866,17 @@ static void action_command(EEPRO100State *s)
         bool success = true;
         //~ bool bit_sf = ((command & 0x0008) != 0);
         uint16_t cmd = command & 0x0007;
-        s->cu_offset = le32_to_cpu(tx.link);
+        s->cu_offset = le32_to_cpu(s->tx.link);
         switch (cmd) {
         case CmdNOp:
             /* Do nothing. */
             break;
         case CmdIASetup:
-            cpu_physical_memory_read(cb_address + 8, &s->conf.macaddr.a[0], 6);
+            cpu_physical_memory_read(s->cb_address + 8, &s->conf.macaddr.a[0], 6);
             TRACE(OTHER, logout("macaddr: %s\n", nic_dump(&s->macaddr[0], 6)));
             break;
         case CmdConfigure:
-            cpu_physical_memory_read(cb_address + 8, &s->configuration[0],
+            cpu_physical_memory_read(s->cb_address + 8, &s->configuration[0],
                                      sizeof(s->configuration));
             TRACE(OTHER, logout("configuration: %s\n", nic_dump(&s->configuration[0], 16)));
             break;
@@ -796,95 +884,12 @@ static void action_command(EEPRO100State *s)
             //~ missing("multicast list");
             break;
         case CmdTx:
-            (void)0;
-            uint32_t tbd_array = le32_to_cpu(tx.tx_desc_addr);
-            uint16_t tcb_bytes = (le16_to_cpu(tx.tcb_bytes) & 0x3fff);
-            TRACE(RXTX, logout
-                ("transmit, TBD array address 0x%08x, TCB byte count 0x%04x, TBD count %u\n",
-                 tbd_array, tcb_bytes, tx.tbd_count));
-
             if (bit_nc) {
                 missing("CmdTx: NC = 0");
                 success = false;
                 break;
             }
-            //~ assert(!bit_sf);
+            tx_command(s);
-            if (tcb_bytes > 2600) {
-                logout("TCB byte count too large, using 2600\n");
-                tcb_bytes = 2600;
-            }
-            /* Next assertion fails for local configuration. */
-            //~ assert((tcb_bytes > 0) || (tbd_array != 0xffffffff));
-            if (!((tcb_bytes > 0) || (tbd_array != 0xffffffff))) {
-                logout
-                    ("illegal values of TBD array address and TCB byte count!\n");
-            }
-            // sends larger than MAX_ETH_FRAME_SIZE are allowed, up to 2600 bytes
-            uint8_t buf[2600];
-            uint16_t size = 0;
-            uint32_t tbd_address = cb_address + 0x10;
-            assert(tcb_bytes <= sizeof(buf));
-            while (size < tcb_bytes) {
-                uint32_t tx_buffer_address = ldl_phys(tbd_address);
-                uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
-                //~ uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
-                tbd_address += 8;
-                TRACE(RXTX, logout
-                    ("TBD (simplified mode): buffer address 0x%08x, size 0x%04x\n",
-                     tx_buffer_address, tx_buffer_size));
-                tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
-                cpu_physical_memory_read(tx_buffer_address, &buf[size],
-                                         tx_buffer_size);
-                size += tx_buffer_size;
-            }
-            if (tbd_array == 0xffffffff) {
-                /* Simplified mode. Was already handled by code above. */
-            } else {
-                /* Flexible mode. */
-                uint8_t tbd_count = 0;
-                if (s->has_extended_tcb_support && !(s->configuration[6] & BIT(4))) {
-                    /* Extended Flexible TCB. */
-                    for (; tbd_count < 2; tbd_count++) {
-                        uint32_t tx_buffer_address = ldl_phys(tbd_address);
-                        uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
-                        uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
-                        tbd_address += 8;
-                        TRACE(RXTX, logout
-                            ("TBD (extended flexible mode): buffer address 0x%08x, size 0x%04x\n",
-                             tx_buffer_address, tx_buffer_size));
-                        tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
-                        cpu_physical_memory_read(tx_buffer_address, &buf[size],
-                                                 tx_buffer_size);
-                        size += tx_buffer_size;
-                        if (tx_buffer_el & 1) {
-                            break;
-                        }
-                    }
-                }
-                tbd_address = tbd_array;
-                for (; tbd_count < tx.tbd_count; tbd_count++) {
-                    uint32_t tx_buffer_address = ldl_phys(tbd_address);
-                    uint16_t tx_buffer_size = lduw_phys(tbd_address + 4);
-                    uint16_t tx_buffer_el = lduw_phys(tbd_address + 6);
-                    tbd_address += 8;
-                    TRACE(RXTX, logout
-                        ("TBD (flexible mode): buffer address 0x%08x, size 0x%04x\n",
-                         tx_buffer_address, tx_buffer_size));
-                    tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);
-                    cpu_physical_memory_read(tx_buffer_address, &buf[size],
-                                             tx_buffer_size);
-                    size += tx_buffer_size;
-                    if (tx_buffer_el & 1) {
-                        break;
-                    }
-                }
-            }
-            TRACE(RXTX, logout("%p sending frame, len=%d,%s\n", s, size, nic_dump(buf, size)));
-            qemu_send_packet(&s->nic->nc, buf, size);
-            s->statistics.tx_good_frames++;
-            /* Transmit with bad status would raise an CX/TNO interrupt.
-             * (82557 only). Emulation never has bad status. */
-            //~ eepro100_cx_interrupt(s);
             break;
         case CmdTDR:
             TRACE(OTHER, logout("load microcode\n"));
@@ -897,7 +902,7 @@ static void action_command(EEPRO100State *s)
             break;
         }
         /* Write new status. */
-        stw_phys(cb_address, status | 0x8000 | (success ? 0x2000 : 0));
+        stw_phys(s->cb_address, status | 0x8000 | (success ? 0x2000 : 0));
         if (bit_i) {
             /* CU completed action. */
             eepro100_cx_interrupt(s);