1 files changed, 289 insertions, 0 deletions
diff --git a/host/usrp_e_utils/usrp-e-loopback.cpp b/host/usrp_e_utils/usrp-e-loopback.cpp
new file mode 100644
index 000000000..5b1003440
--- /dev/null
+++ b/host/usrp_e_utils/usrp-e-loopback.cpp
@@ -0,0 +1,289 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "common.hpp"
+#include <cstdlib>
+#include <cstdio>
+#include <ctime>
+#include <iostream>
+#include <boost/thread/thread.hpp>
+#include <boost/format.hpp>
+#include <boost/cstdint.hpp>
+#include <sys/mman.h> //mmap
+#include <unistd.h> //getpagesize
+#include <poll.h> //poll
+
+static const size_t bytes_per_frame = 2048;
+
+static const int poll_timeout_ms = 100;
+
+struct loopback_pkt_hdr_type{
+    boost::uint32_t words32;
+    boost::uint32_t checksum;
+    boost::uint64_t seq_num;
+};
+
+struct loopback_pkt_type{
+    loopback_pkt_hdr_type hdr;
+    boost::uint32_t data[(bytes_per_frame-sizeof(loopback_pkt_hdr_type))/sizeof(boost::uint32_t)];
+};
+
+static ring_buffer_info (*recv_info)[];
+static ring_buffer_info (*send_info)[];
+static loopback_pkt_type (*recv_buff)[];
+static loopback_pkt_type (*send_buff)[];
+
+static struct usrp_e_ring_buffer_size_t rb_size;
+
+static bool running = true;
+
+static boost::uint64_t seq_errors = 0;
+static boost::uint64_t checksum_errors = 0;
+static boost::uint64_t sent_words32 = 0;
+static boost::uint64_t recvd_words32 = 0;
+
+static inline void print_pkt(const loopback_pkt_type &pkt){
+    std::cout << std::endl;
+    std::cout << "pkt.hdr.words32 " << pkt.hdr.words32 << std::endl;
+    std::cout << "pkt.hdr.checksum " << pkt.hdr.checksum << std::endl;
+    std::cout << "pkt.hdr.seq_num " << pkt.hdr.seq_num << std::endl;
+}
+
+boost::uint32_t my_checksum(void *buff, size_t size32){
+    boost::uint32_t x = 0;
+    for (size_t i = 0; i < size32; i++){
+        x += reinterpret_cast<boost::uint32_t *>(buff)[i];
+        x ^= reinterpret_cast<boost::uint32_t *>(buff)[i];
+    }
+    return x;
+}
+
+/***********************************************************************
+ * Read thread - recv frames and verify checksum
+ **********************************************************************/
+static void read_thread(void){
+    std::cout << "start read thread... " << std::endl;
+
+    boost::uint64_t seq_num = 0;
+    size_t index = 0;
+
+    while (running){
+
+        loopback_pkt_type &pkt = (*recv_buff)[index];
+        ring_buffer_info &info = (*recv_info)[index];
+
+        //wait for frame available
+        if (not (info.flags & RB_USER)){
+            pollfd pfd;
+            pfd.fd = fp;
+            pfd.events = POLLIN;
+            if (poll(&pfd, 1, poll_timeout_ms) <= 0){
+                std::cout << "Read poll timeout, exiting read thread!" << std::endl;
+                running = false;
+                return;
+            }
+        }
+        info.flags = RB_USER_PROCESS;
+
+        //print_pkt(pkt);
+
+        //handle checksum
+        const boost::uint32_t expected_checksum = pkt.hdr.checksum;
+        pkt.hdr.checksum = 0; //set to zero for calculation
+        const boost::uint32_t actual_checksum = my_checksum(&pkt, pkt.hdr.words32);
+        if (expected_checksum != actual_checksum){
+            checksum_errors++;
+            std::cerr << "C";
+        }
+        else{
+            recvd_words32 += pkt.hdr.words32;
+        }
+
+        //handle sequence
+        if (seq_num != pkt.hdr.seq_num){
+            seq_errors++;
+            std::cerr << "S";
+        }
+        seq_num = pkt.hdr.seq_num+1;
+
+        //release the packet
+        info.flags = RB_KERNEL;
+
+        //increment index and wrap around to zero
+        index++;
+        if (index == size_t(rb_size.num_rx_frames)) index = 0;
+    }
+
+}
+
+/***********************************************************************
+ * Write thread - send frames and calculate checksum
+ **********************************************************************/
+static void write_thread(const size_t num_words32){
+    std::cout << "start write thread... " << std::endl;
+
+    srandom(std::time(NULL));
+
+    boost::uint64_t seq_num = 0;
+    size_t index = 0;
+
+    //write into tmp and memcopy into pkt to avoid cache issues
+    loopback_pkt_type pkt_tmp;
+
+    while (running){
+
+        ring_buffer_info &info = (*send_info)[index];
+
+        //wait for frame available
+        if (not (info.flags & RB_KERNEL)){
+            pollfd pfd;
+            pfd.fd = fp;
+            pfd.events = POLLOUT;
+            if (poll(&pfd, 1, poll_timeout_ms) <= 0){
+                std::cout << "Write poll timeout, exiting write thread!" << std::endl;
+                running = false;
+                return;
+            }
+        }
+
+        //fill packet header and body
+        const boost::uint32_t seed = random();
+        pkt_tmp.hdr.words32 = sizeof(pkt_tmp.hdr)/sizeof(boost::uint32_t) + num_words32;
+        pkt_tmp.hdr.checksum = 0; //set to zero for checksum()
+        pkt_tmp.hdr.seq_num = seq_num++;
+        for (size_t i = 0; i < num_words32; i++) pkt_tmp.data[i] = seed + i;
+        pkt_tmp.hdr.checksum = my_checksum(&pkt_tmp, pkt_tmp.hdr.words32);
+        sent_words32 += pkt_tmp.hdr.words32;
+
+        loopback_pkt_type &pkt = (*send_buff)[index];
+        std::memcpy(&pkt, &pkt_tmp, pkt_tmp.hdr.words32*sizeof(boost::uint32_t));
+
+        //print_pkt(pkt);
+
+        //commit the packet
+        info.len = pkt_tmp.hdr.words32*sizeof(boost::uint32_t);
+        info.flags = RB_USER;
+        ::write(fp, NULL, 0);
+
+        //increment index and wrap around to zero
+        index++;
+        if (index == size_t(rb_size.num_tx_frames)) index = 0;
+    }
+}
+
+/***********************************************************************
+ * Setup memory mapped ring buffer
+ **********************************************************************/
+static void setup_ring(void){
+    std::cout << "setup memory mapped ring buffer... " << std::flush;
+
+    //calculate various sizes
+    const size_t page_size = getpagesize();
+    ioctl(fp, USRP_E_GET_RB_INFO, &rb_size);
+    const size_t map_size = (rb_size.num_pages_rx_flags + rb_size.num_pages_tx_flags) * page_size +
+        (rb_size.num_rx_frames + rb_size.num_tx_frames) * (page_size >> 1);
+
+    //call into memory map
+    void *mem = ::mmap(0, map_size, PROT_READ|PROT_WRITE, MAP_SHARED, fp, 0);
+    if (mem == MAP_FAILED) {
+        std::cerr << "mmap failed" << std::endl;
+        std::exit(-1);
+    }
+
+    //calculate the memory offsets for info and buffers
+    const size_t recv_info_off = 0;
+    const size_t recv_buff_off = recv_info_off + (rb_size.num_pages_rx_flags * page_size);
+    const size_t send_info_off = recv_buff_off + (rb_size.num_rx_frames * page_size/2);
+    const size_t send_buff_off = send_info_off + (rb_size.num_pages_tx_flags * page_size);
+
+    //set the internal pointers for info and buffers
+    typedef ring_buffer_info (*rbi_pta)[];
+    typedef loopback_pkt_type (*pkt_pta)[];
+    char *rb_ptr = reinterpret_cast<char *>(mem);
+    recv_info = reinterpret_cast<rbi_pta>(rb_ptr + recv_info_off);
+    recv_buff = reinterpret_cast<pkt_pta>(rb_ptr + recv_buff_off);
+    send_info = reinterpret_cast<rbi_pta>(rb_ptr + send_info_off);
+    send_buff = reinterpret_cast<pkt_pta>(rb_ptr + send_buff_off);
+
+    std::cout << "done" << std::endl;
+}
+
+/***********************************************************************
+ * Main
+ **********************************************************************/
+#include <boost/program_options.hpp>
+
+int main(int argc, char *argv[]){
+
+    //variables to be set by po
+    double duration;
+    size_t nwords;
+
+    //setup the program options
+    namespace po = boost::program_options;
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("duration", po::value<double>(&duration)->default_value(10), "number of seconds to run loopback")
+        ("nwords", po::value<size_t>(&nwords)->default_value(400), "number of words32 to send per packet")
+    ;
+    po::variables_map vm;
+    po::store(po::parse_command_line(argc, argv, desc), vm);
+    po::notify(vm);
+
+    //print the help message
+    if (vm.count("help")){
+        std::cout << boost::format("UHD USRP-E-Loopback %s") % desc << std::endl;
+        return ~0;
+    }
+
+    if ((fp = ::open("/dev/usrp_e0", O_RDWR)) < 0){
+        std::cerr << "Open failed" << std::endl;
+        return -1;
+    }
+
+    //set the mode to loopback
+    poke16(E100_REG_MISC_XFER_RATE, (1<<8) | (1<<9));
+
+    //setup the ring buffer
+    setup_ring();
+
+    //spawn threads
+    boost::thread_group tg;
+    tg.create_thread(boost::bind(&read_thread));
+    tg.create_thread(boost::bind(&write_thread, nwords));
+
+    const boost::system_time start_time = boost::get_system_time();
+    const boost::system_time finish_time = start_time + boost::posix_time::milliseconds(long(duration*1000));
+    while (boost::get_system_time() < finish_time){
+        boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
+        std::cerr << ".";
+    }
+    running = false;
+    tg.join_all();
+
+    std::cout << std::endl;
+    std::cout << "seq_errors          " << seq_errors << std::endl;
+    std::cout << "checksum_errors     " << checksum_errors << std::endl;
+    std::cout << "sent_words32        " << sent_words32 << std::endl;
+    std::cout << "recvd_words32       " << recvd_words32 << std::endl;
+    std::cout << "approx send rate    " << (sent_words32/duration)/1e6 << "Msps" << std::endl;
+    std::cout << "approx recv rate    " << (recvd_words32/duration)/1e6 << "Msps" << std::endl;
+
+    ::close(fp);
+    return seq_errors + checksum_errors;
+}