edge: Use RLC data block encoding functions
This commit removes the use of struct rlc_dl_header from
gprs_rlcmac_dl_tbf::create_dl_acked_block and
gprs_rlcmac_dl_tbf::create_new_bsn. Instead of patching the
data area directly, the RLC block encoding functions are used.
Note that the data unit encoding is still hard-coded to GPRS in
create_new_bsn, so using MCS 1-4 (albeit being supported by the
encoder) will not work yet.
Sponsored-by: On-Waves ehf
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index ac1c253..a1f8b60 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -27,6 +27,7 @@
#include <gprs_bssgp_pcu.h>
#include <gprs_codel.h>
#include <decoding.h>
+#include <encoding.h>
#include "pcu_utils.h"
@@ -423,13 +424,13 @@
struct msgb *gprs_rlcmac_dl_tbf::create_new_bsn(const uint32_t fn, const uint8_t ts)
{
- struct rlc_dl_header *rh;
struct rlc_li_field *li;
uint8_t *delimiter, *data, *e_pointer;
uint16_t space, chunk;
gprs_rlc_data *rlc_data;
const uint16_t bsn = m_window.v_s();
GprsCodingScheme cs = current_cs();
+ gprs_rlc_data_block_info *rdbi;
if (m_llc.frame_length() == 0)
schedule_next_frame();
@@ -439,29 +440,27 @@
OSMO_ASSERT(cs.isValid());
- /* total length of block, including spare bits */
- const uint8_t block_length = cs.sizeDL();
- /* length of usable data of block, w/o spare bits (GPRS), inc. MAC */
- const uint8_t block_data_len = cs.maxBytesDL();
+ /* length of usable data block (single data unit w/o header) */
+ const uint8_t block_data_len = cs.maxDataBlockBytes();
/* now we still have untransmitted LLC data, so we fill mac block */
rlc_data = m_rlc.block(bsn);
data = rlc_data->prepare(block_data_len);
rlc_data->cs = cs;
+ rlc_data->len = block_data_len;
- rh = (struct rlc_dl_header *)data;
- rh->pt = 0; /* Data Block */
- rh->rrbp = rh->s_p = 0; /* Polling, set later, if required */
- rh->usf = 7; /* will be set at scheduler */
- rh->pr = 0; /* FIXME: power reduction */
- rh->tfi = m_tfi; /* TFI */
- rh->fbi = 0; /* Final Block Indicator, set late, if true */
- rh->bsn = bsn; /* Block Sequence Number */
- rh->e = 0; /* Extension bit, maybe set later */
- e_pointer = data + 2; /* points to E of current chunk */
- data += sizeof(*rh);
+ rdbi = &(rlc_data->block_info);
+ memset(rdbi, 0, sizeof(*rdbi));
+ rdbi->data_len = block_data_len;
+
+ rdbi->cv = 15; /* Final Block Indicator, set late, if true */
+ rdbi->bsn = bsn; /* Block Sequence Number */
+ rdbi->e = 1; /* Extension bit, maybe set later (1: no extension) */
+
+ e_pointer = NULL; /* points to E of current chunk if it is stored in an
+ extension byte */
delimiter = data; /* where next length header would be stored */
- space = block_data_len - sizeof(*rh);
+ space = block_data_len;
while (1) {
if (m_llc.frame_length() == 0) {
/* A header will need to by added, so we just need
@@ -492,7 +491,8 @@
"only remaining space, and we are done\n",
chunk, space);
/* block is filled, so there is no extension */
- *e_pointer |= 0x01;
+ if (e_pointer)
+ *e_pointer |= 0x01;
/* fill only space */
m_llc.consume(data, space);
/* return data block as message */
@@ -510,12 +510,13 @@
"len=%d\n", tbf_name(this), m_llc.frame_length());
gprs_rlcmac_dl_bw(this, m_llc.frame_length());
/* block is filled, so there is no extension */
- *e_pointer |= 0x01;
+ if (e_pointer)
+ *e_pointer |= 0x01;
/* fill space */
m_llc.consume(data, space);
m_llc.reset();
/* final block */
- rh->fbi = 1; /* we indicate final block */
+ rdbi->cv = 0; /* we indicate final block */
request_dl_ack();
set_state(GPRS_RLCMAC_FINISHED);
/* return data block as message */
@@ -559,6 +560,7 @@
li->e = 0; /* Extension bit, maybe set later */
li->m = 0; /* will be set later, if there is more LLC data */
li->li = chunk; /* length of chunk */
+ rdbi->e = 0; /* 0: extensions present */
e_pointer = delimiter; /* points to E of current delimiter */
delimiter++;
/* copy (rest of) LLC frame to space and reset later */
@@ -582,7 +584,7 @@
"done.\n");
li->e = 1; /* we cannot extend */
- rh->fbi = 1; /* we indicate final block */
+ rdbi->cv = 0; /* we indicate final block */
request_dl_ack();
set_state(GPRS_RLCMAC_FINISHED);
break;
@@ -593,10 +595,9 @@
li->e = 1; /* we cannot extend */
break;
}
- LOGP(DRLCMACDL, LOGL_DEBUG, "data block: %s\n",
- osmo_hexdump(rlc_data->block, block_length));
-#warning "move this up?"
- rlc_data->len = block_length;
+ LOGP(DRLCMACDL, LOGL_DEBUG, "data block (BSN %d, %s): %s\n",
+ bsn, rlc_data->cs.name(),
+ osmo_hexdump(rlc_data->block, block_data_len));
/* raise send state and set ack state array */
m_window.m_v_b.mark_unacked(bsn);
m_window.increment_send();
@@ -608,16 +609,30 @@
const uint32_t fn, const uint8_t ts,
const int index)
{
- uint8_t *data;
- struct rlc_dl_header *rh;
+ uint8_t *block_data, *msg_data;
struct msgb *dl_msg;
- uint8_t len;
+ unsigned msg_len;
bool need_poll;
+ /* TODO: support MCS-7 - MCS-9, where data_block_idx can be 1 */
+ unsigned int data_block_idx = 0;
+
+ gprs_rlc_data_info rlc;
+ GprsCodingScheme cs;
+ gprs_rlc_data_block_info *rdbi;
/* get data and header from current block */
- data = m_rlc.block(index)->block;
- len = m_rlc.block(index)->len;
- rh = (struct rlc_dl_header *)data;
+ block_data = m_rlc.block(index)->block;
+
+ cs = m_rlc.block(index)->cs;
+
+ gprs_rlc_data_info_init_dl(&rlc, cs);
+
+ rlc.usf = 7; /* will be set at scheduler */
+ rlc.pr = 0; /* FIXME: power reduction */
+ rlc.tfi = m_tfi; /* TFI */
+
+ rlc.block_info[data_block_idx] = m_rlc.block(index)->block_info;
+ rdbi = &rlc.block_info[data_block_idx];
/* If the TBF has just started, relate frames_since_last_poll to the
* current fn */
@@ -625,9 +640,7 @@
m_last_dl_poll_fn = fn;
need_poll = state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
- /* Clear Polling, if still set in history buffer */
- rh->s_p = 0;
-
+
/* poll after POLL_ACK_AFTER_FRAMES frames, or when final block is tx.
*/
if (m_tx_counter >= POLL_ACK_AFTER_FRAMES || m_dl_ack_requested ||
@@ -662,7 +675,7 @@
"TS %d\n", ts);
m_tx_counter = 0;
/* start timer whenever we send the final block */
- if (rh->fbi == 1)
+ if (rdbi->cv == 0)
tbf_timer_start(this, 3191, bts_data()->t3191, 0);
/* schedule polling */
@@ -676,8 +689,8 @@
m_dl_ack_requested = false;
/* set polling in header */
- rh->rrbp = 0; /* N+13 */
- rh->s_p = 1; /* Polling */
+ rlc.rrbp = 0; /* N+13 */
+ rlc.es_p = 1; /* Polling */
m_last_dl_poll_fn = poll_fn;
@@ -687,15 +700,25 @@
}
}
+ msg_len = cs.sizeDL();
+
/* return data block as message */
- dl_msg = msgb_alloc(len, "rlcmac_dl_data");
+ dl_msg = msgb_alloc(msg_len, "rlcmac_dl_data");
if (!dl_msg)
return NULL;
+ msg_data = msgb_put(dl_msg, msg_len);
+ Encoding::rlc_write_dl_data_header(&rlc, msg_data);
+ Encoding::rlc_copy_from_aligned_buffer(&rlc, data_block_idx, msg_data,
+ block_data);
+
+ LOGP(DRLCMACDL, LOGL_DEBUG, "msg block (BSN %d, %s): %s\n",
+ index, cs.name(),
+ msgb_hexdump(dl_msg));
+
/* Increment TX-counter */
m_tx_counter++;
- memcpy(msgb_put(dl_msg, len), data, len);
bts->rlc_sent();
return dl_msg;