From 56e00b6e8b047b5dee69f12912dc9a92ec423018 Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Tue, 5 Jul 2016 19:05:42 +0200
Subject: [PATCH] Improve a bit the RTL8139 driver

---
 kernel/src/rtl8139.cpp | 49 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/kernel/src/rtl8139.cpp b/kernel/src/rtl8139.cpp
index 47a8ec18..dbea0dcd 100644
--- a/kernel/src/rtl8139.cpp
+++ b/kernel/src/rtl8139.cpp
@@ -17,10 +17,12 @@
 #define MAC4 0x04
 #define RBSTART 0x30
 #define CMD 0x37
-#define IMR 0x3C
-#define ISR 0x3E
-#define RCR 0x44
+#define IMR 0x3C //Interrupt mask register
+#define ISR 0x3E //Interrupt status register
+#define RCR 0x44 //Receive Config Register
 #define CONFIG_1 0x52
+#define RX_BUF_PTR 0x38
+#define RX_BUF_ADDR 0x3A
 
 #define RCR_AAP  (1 << 0) /* Accept All Packets */
 #define RCR_APM  (1 << 1) /* Accept Physical Match Packets */
@@ -34,6 +36,8 @@ struct rtl8139_t {
     uint32_t iobase;
     uint64_t phys_buffer_rx;
     uint64_t buffer_rx;
+
+    uint64_t cur_rx; //Index inside the buffer
 };
 
 //TODO Add a way so that the interrupt handler is able to pass a void ptr to the handler
@@ -45,8 +49,44 @@ void packet_handler(interrupt::syscall_regs*){
 
     auto& desc = *saved_desc;
 
+    //This should be a packet header
+    uint16_t header = *reinterpret_cast<uint16_t*>(desc.buffer_rx);
+
+    logging::logf(logging::log_level::TRACE, "rtl8139: Packet Received %u\n", uint64_t(header));
+
+    // Get the interrupt status
+    auto status = in_word(desc.iobase + ISR);
+
     // Acknowledge the handling of the packet
-    out_word(desc.iobase + ISR, 0x1);
+    out_word(desc.iobase + ISR, status);
+
+#define RX_OK 0x01
+#define CMD_NOT_EMPTY 0x01
+
+    if(status & RX_OK){
+        logging::logf(logging::log_level::TRACE, "rtl8139: Receive status OK\n");
+
+        auto cur_rx = desc.cur_rx;
+        auto buffer_rx = desc.buffer_rx;
+
+        while((in_byte(desc.iobase + CMD) & CMD_NOT_EMPTY) == 0){
+            auto packet_header = *reinterpret_cast<uint16_t*>(buffer_rx + cur_rx);
+            auto packet_length = *reinterpret_cast<uint16_t*>(buffer_rx + cur_rx + 2);
+            auto packet_only_length = packet_length - 4;
+
+            logging::logf(logging::log_level::TRACE, "rtl8139: Handle Packet Received %u\n", uint64_t(packet_header));
+            logging::logf(logging::log_level::TRACE, "rtl8139: Handle Packet Received %u\n", uint64_t(packet_length));
+
+            cur_rx = (cur_rx + packet_length + 4 + 3) & ~3;
+            out_word(desc.iobase + RX_BUF_PTR, cur_rx - 16);
+        }
+
+        logging::logf(logging::log_level::TRACE, "rtl8139: Packet Handled\n");
+
+        desc.cur_rx = cur_rx;
+    } else {
+        logging::logf(logging::log_level::TRACE, "rtl8139: Receive status not OK\n");
+    }
 }
 
 } //end of anonymous namespace
@@ -92,6 +132,7 @@ void rtl8139::init_driver(network::interface_descriptor& interface, pci::device_
 
     desc->phys_buffer_rx = buffer_rx_phys;
     desc->buffer_rx = buffer_rx_virt;
+    desc->cur_rx = 0;
 
     // 6. Register IRQ handler