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-rw-r--r--firmware/microblaze/lib/bsm12.c319
1 files changed, 319 insertions, 0 deletions
diff --git a/firmware/microblaze/lib/bsm12.c b/firmware/microblaze/lib/bsm12.c
new file mode 100644
index 000000000..3f17fe42d
--- /dev/null
+++ b/firmware/microblaze/lib/bsm12.c
@@ -0,0 +1,319 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009 Free Software Foundation, Inc.
+ *
+ * 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/>.
+ */
+
+/*
+ * buffer state machine: 1 input to two outputs
+ *
+ * Typically used to read packets from the ethernet and then after inspecting,
+ * handle the packet in firmware or pass it on to 1 of the 2 buffer destinations.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "bsm12.h"
+#include "memory_map.h"
+#include "buffer_pool.h"
+#include <stdbool.h>
+#include "nonstdio.h"
+#include <stdlib.h>
+
+typedef enum {
+ BS_EMPTY,
+ BS_FILLING,
+ BS_FULL,
+ BS_EMPTYING,
+} buffer_state_t;
+
+static buffer_state_t buffer_state[NBUFFERS];
+static uint32_t last_send_ctrl[NBUFFERS];
+static int8_t buffer_target[NBUFFERS]; // -1, 0 or 1.
+static uint8_t buffer_dst[NBUFFERS]; // 0 or 1. Valid only when BF_EMPTYING
+
+#define ST_IDLE (-1)
+
+void
+bsm12_init(bsm12_t *sm, int buf0,
+ const buf_cmd_args_t *recv,
+ const buf_cmd_args_t *send0,
+ const buf_cmd_args_t *send1,
+ bsm12_inspector_t inspect)
+{
+ if (buf0 & 0x3) // precondition: buf0 % 4 == 0
+ abort();
+
+ sm->buf0 = buf0;
+ sm->running = false;
+ sm->recv_args = *recv;
+ sm->send_args[0] = *send0;
+ sm->send_args[1] = *send1;
+
+ sm->rx_state = ST_IDLE;
+ sm->tx_state[0] = ST_IDLE;
+ sm->tx_state[1] = ST_IDLE;
+
+ sm->inspect = inspect;
+
+ sm->bps_error = BPS_ERROR(buf0 + 0) | BPS_ERROR(buf0 + 1) | BPS_ERROR(buf0 + 2);
+ sm->bps_done = BPS_DONE(buf0 + 0) | BPS_DONE(buf0 + 1) | BPS_DONE(buf0 + 2);
+ sm->bps_error_or_done = sm->bps_error | sm->bps_done;
+
+ // How much to adjust the last_line register.
+ // It's 1 for everything but the ethernet.
+ sm->last_line_adj = recv->port == PORT_ETH ? 3 : 1;
+
+ buffer_state[sm->buf0 + 0] = BS_EMPTY;
+ buffer_state[sm->buf0 + 1] = BS_EMPTY;
+ buffer_state[sm->buf0 + 2] = BS_EMPTY;
+
+ buffer_target[sm->buf0 + 0] = -1;
+ buffer_target[sm->buf0 + 1] = -1;
+ buffer_target[sm->buf0 + 2] = -1;
+
+ for (int i = 0; i < NBUFFERS; i++)
+ sm->next_buf[i] = buf0;
+
+ sm->next_buf[buf0 + 0] = buf0 + 1;
+ sm->next_buf[buf0 + 1] = buf0 + 2;
+ sm->next_buf[buf0 + 2] = buf0 + 0;
+
+ for (int i = 0; i < 3; i++){
+ sm->precomputed_receive_to_buf_ctrl_word[i] =
+ (BPC_READ
+ | BPC_BUFFER(sm->buf0 + i)
+ | BPC_PORT(sm->recv_args.port)
+ | BPC_STEP(1)
+ | BPC_FIRST_LINE(sm->recv_args.first_line)
+ | BPC_LAST_LINE(sm->recv_args.last_line));
+
+ for (int j = 0; j < 2; j++){
+ sm->precomputed_send_from_buf_ctrl_word[i][j] =
+ (BPC_WRITE
+ | BPC_BUFFER(sm->buf0 + i)
+ | BPC_PORT(sm->send_args[j].port)
+ | BPC_STEP(1)
+ | BPC_FIRST_LINE(sm->send_args[j].first_line)
+ | BPC_LAST_LINE(0)); // last line filled in at runtime
+ }
+ }
+}
+
+static inline void
+bsm12_receive_to_buf(bsm12_t *sm, int bufno)
+{
+ buffer_pool_ctrl->ctrl = sm->precomputed_receive_to_buf_ctrl_word[bufno & 0x3];
+}
+
+static inline void
+bsm12_send_from_buf(bsm12_t *sm, int bufno, int dst_idx)
+{
+ dst_idx &= 0x1;
+
+ uint32_t t =
+ (sm->precomputed_send_from_buf_ctrl_word[bufno & 0x3][dst_idx]
+ | BPC_LAST_LINE(buffer_pool_status->last_line[bufno] - sm->last_line_adj));
+
+ buffer_pool_ctrl->ctrl = t;
+ last_send_ctrl[bufno] = t;
+ buffer_dst[bufno] = dst_idx;
+}
+
+static inline void
+bsm12_resend_from_buf(bsm12_t *sm, int bufno)
+{
+ buffer_pool_ctrl->ctrl = last_send_ctrl[bufno];
+}
+
+void
+bsm12_start(bsm12_t *sm)
+{
+ sm->running = true;
+
+ buffer_state[sm->buf0 + 0] = BS_EMPTY;
+ buffer_state[sm->buf0 + 1] = BS_EMPTY;
+ buffer_state[sm->buf0 + 2] = BS_EMPTY;
+
+ buffer_target[sm->buf0 + 0] = -1;
+ buffer_target[sm->buf0 + 1] = -1;
+ buffer_target[sm->buf0 + 2] = -1;
+
+ bp_clear_buf(sm->buf0 + 0);
+ bp_clear_buf(sm->buf0 + 1);
+ bp_clear_buf(sm->buf0 + 2);
+
+ sm->rx_state = 0;
+ sm->tx_state[0] = ST_IDLE;
+ sm->tx_state[1] = ST_IDLE;
+ bsm12_receive_to_buf(sm, sm->buf0);
+ buffer_state[sm->buf0] = BS_FILLING;
+}
+
+void
+bsm12_stop(bsm12_t *sm)
+{
+ sm->running = false;
+ bp_clear_buf(sm->buf0 + 0);
+ bp_clear_buf(sm->buf0 + 1);
+ bp_clear_buf(sm->buf0 + 2);
+ buffer_state[sm->buf0 + 0] = BS_EMPTY;
+ buffer_state[sm->buf0 + 1] = BS_EMPTY;
+ buffer_state[sm->buf0 + 2] = BS_EMPTY;
+}
+
+static void bsm12_process_helper(bsm12_t *sm, int buf_this);
+static void bsm12_error_helper(bsm12_t *sm, int buf_this);
+
+void
+bsm12_process_status(bsm12_t *sm, uint32_t status)
+{
+ // anything for us?
+ if ((status & sm->bps_error_or_done) == 0 || !sm->running)
+ return;
+
+ if (status & sm->bps_error){
+ // Most likely an ethernet Rx error. We just restart the transfer.
+ if (status & (BPS_ERROR(sm->buf0 + 0)))
+ bsm12_error_helper(sm, sm->buf0 + 0);
+
+ if (status & (BPS_ERROR(sm->buf0 + 1)))
+ bsm12_error_helper(sm, sm->buf0 + 1);
+
+ if (status & (BPS_ERROR(sm->buf0 + 2)))
+ bsm12_error_helper(sm, sm->buf0 + 2);
+ }
+
+ if (status & BPS_DONE(sm->buf0 + 0))
+ bsm12_process_helper(sm, sm->buf0 + 0);
+
+ if (status & BPS_DONE(sm->buf0 + 1))
+ bsm12_process_helper(sm, sm->buf0 + 1);
+
+ if (status & BPS_DONE(sm->buf0 + 2))
+ bsm12_process_helper(sm, sm->buf0 + 2);
+}
+
+ static void
+bsm12_process_helper(bsm12_t *sm, int buf_this)
+{
+ bp_clear_buf(buf_this);
+
+ if (buffer_state[buf_this] == BS_FILLING){
+
+ buffer_state[buf_this] = BS_FULL;
+ buffer_target[buf_this] = -1;
+
+ //
+ // where does this packet go?
+ //
+ int dst = sm->inspect(sm, buf_this);
+ if (dst == -1){
+ //
+ // f/w handled the packet; refill the buffer
+ //
+ bsm12_receive_to_buf(sm, buf_this);
+ buffer_state[buf_this] = BS_FILLING;
+ buffer_target[buf_this] = -1;
+ sm->rx_state = buf_this & 0x3;
+ }
+ else { // goes to dst 0 or 1
+ //
+ // If the next buffer is empty, start a receive on it
+ //
+ int t = sm->next_buf[buf_this];
+ if (buffer_state[t] == BS_EMPTY){
+ bsm12_receive_to_buf(sm, t);
+ buffer_state[t] = BS_FILLING;
+ buffer_target[t] = -1;
+ sm->rx_state = t & 0x3;
+ }
+ else
+ sm->rx_state = ST_IDLE;
+
+ //
+ // If the destination is idle, start the xfer, othewise remember it
+ //
+ if (sm->tx_state[dst] == ST_IDLE){
+ bsm12_send_from_buf(sm, buf_this, dst);
+ sm->tx_state[dst] = buf_this & 0x3;
+ buffer_state[buf_this] = BS_EMPTYING;
+ buffer_target[buf_this] = -1;
+ }
+ else {
+ buffer_target[buf_this] = dst;
+ }
+ }
+ }
+
+ else { // BS_EMPTYING
+
+ buffer_state[buf_this] = BS_EMPTY;
+ buffer_target[buf_this] = -1;
+
+ if (sm->rx_state == ST_IDLE){ // fire off another receive
+ sm->rx_state = buf_this & 0x3;
+ bsm12_receive_to_buf(sm, buf_this);
+ buffer_state[buf_this] = BS_FILLING;
+ buffer_target[buf_this] = -1;
+ }
+
+ int dst = buffer_dst[buf_this]; // the dst we were emptying into
+ // is the next buffer full and for us?
+ int t = sm->next_buf[buf_this];
+ if (buffer_target[t] == dst){ // yes,
+ bsm12_send_from_buf(sm, t, dst); // send it
+ buffer_state[t] = BS_EMPTYING;
+ buffer_target[t] = -1;
+ sm->tx_state[dst] = t & 0x3;
+ }
+ // how about the one after that?
+ else if (buffer_target[t=sm->next_buf[t]] == dst){ // yes,
+ bsm12_send_from_buf(sm, t, dst); // send it
+ buffer_state[t] = BS_EMPTYING;
+ buffer_target[t] = -1;
+ sm->tx_state[dst] = t & 0x3;
+ }
+ else {
+ sm->tx_state[dst] = ST_IDLE;
+ }
+ }
+}
+
+static void
+bsm12_error_helper(bsm12_t *sm, int buf_this)
+{
+ bp_clear_buf(buf_this); // clears ERROR flag
+
+ if (buffer_state[buf_this] == BS_FILLING){
+ bsm12_receive_to_buf(sm, buf_this); // restart the xfer
+ }
+ else { // buffer was emptying
+ bsm12_resend_from_buf(sm, buf_this); // restart the xfer
+ }
+}
+
+
+void
+bsm12_handle_tx_underrun(bsm12_t *sm)
+{
+}
+
+void
+bsm12_handle_rx_overrun(bsm12_t *sm)
+{
+}
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