[L] Change in osmocom-bb[master]: trxcon/l1sched: implement CSD scheduling support

27 Aug 2023

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmocom-bb/+/32922 )
Change subject: trxcon/l1sched: implement CSD scheduling support
......................................................................
trxcon/l1sched: implement CSD scheduling support
This patch adds support for TCH/[FH]2.4, TCH/[FH]4.8, TCH/F9.6 and
TCH/F14.4 (including FACCH).  Additional changes made:
* enlarge the maximum TCH burst buffer size to 24 * (2 * 58) bytes;
* enlarge per-l1cs UL/DL burst masks to hold up to 32 bits;
* enlarge per-l1cs DL meas ring buffer to 24 entries;
* enlarge L1SCHED_PRIM_TAILROOM from 256 to 512 bytes;
* enlarge L1CTL_LENGTH from 256 to 512 bytes;
Change-Id: I0d7389a9a5f7019b9316ab1c0115797ff54a0e41
Depends: libosmocore.git Ib482817b5f6a4e3c7299f6e0b3841143b60fc93d
Depends: libosmocore.git I0c7a9c180dcafe64e6aebe53518d3d11e1f29886
Depends: libosmocore.git I4685376c8deb04db670684c9ebf685ad6fc989fa
Related: OS#4396, OS#1572
---
M src/host/trxcon/include/osmocom/bb/l1sched/l1sched.h
M src/host/trxcon/include/osmocom/bb/trxcon/l1ctl_server.h
M src/host/trxcon/src/l1ctl.c
M src/host/trxcon/src/sched_lchan_common.c
M src/host/trxcon/src/sched_lchan_desc.c
M src/host/trxcon/src/sched_lchan_pdtch.c
M src/host/trxcon/src/sched_lchan_tchf.c
M src/host/trxcon/src/sched_lchan_tchh.c
M src/host/trxcon/src/sched_lchan_xcch.c
M src/host/trxcon/src/sched_prim.c
10 files changed, 368 insertions(+), 103 deletions(-)
Approvals:
  fixeria: Looks good to me, approved
  osmith: Looks good to me, but someone else must approve
  Jenkins Builder: Verified

diff --git a/src/host/trxcon/include/osmocom/bb/l1sched/l1sched.h b/src/host/trxcon/include/osmocom/bb/l1sched/l1sched.h
index 98282c1..7d9a5b5 100644
--- a/src/host/trxcon/include/osmocom/bb/l1sched/l1sched.h
+++ b/src/host/trxcon/include/osmocom/bb/l1sched/l1sched.h
@@ -195,9 +195,9 @@
    int8_t rssi;
 };
-/* Simple ring buffer (up to 8 unique measurements) */
+/* Simple ring buffer (up to 24 unique measurements) */
 struct l1sched_lchan_meas_hist {
-	struct l1sched_meas_set buf[8];
+	struct l1sched_meas_set buf[24];
    struct l1sched_meas_set *head;
 };
@@ -213,9 +213,9 @@
    /*! Burst type: GMSK or 8PSK */
    enum l1sched_burst_type burst_type;
    /*! Mask of received bursts */
-	uint8_t rx_burst_mask;
+	uint32_t rx_burst_mask;
    /*! Mask of transmitted bursts */
-	uint8_t tx_burst_mask;
+	uint32_t tx_burst_mask;
    /*! Burst buffer for RX */
    sbit_t *rx_bursts;
    /*! Burst buffer for TX */
@@ -386,7 +386,7 @@
 /* Shared declarations for lchan handlers */
 extern const uint8_t l1sched_nb_training_bits[8][26];
-const char *l1sched_burst_mask2str(const uint8_t *mask, int bits);
+const char *l1sched_burst_mask2str(const uint32_t *mask, int bits);
/* Interleaved TCH/H block TDMA frame mapping */
 bool l1sched_tchh_block_map_fn(enum l1sched_lchan_type chan,
diff --git a/src/host/trxcon/include/osmocom/bb/trxcon/l1ctl_server.h b/src/host/trxcon/include/osmocom/bb/trxcon/l1ctl_server.h
index 8a7e48e..83c61f0 100644
--- a/src/host/trxcon/include/osmocom/bb/trxcon/l1ctl_server.h
+++ b/src/host/trxcon/include/osmocom/bb/trxcon/l1ctl_server.h
@@ -7,7 +7,7 @@
 #include <osmocom/core/timer.h>
 #include <osmocom/core/msgb.h>
-#define L1CTL_LENGTH 256
+#define L1CTL_LENGTH 512
 #define L1CTL_HEADROOM 32
/**
diff --git a/src/host/trxcon/src/l1ctl.c b/src/host/trxcon/src/l1ctl.c
index a45bc2c..0f6bd1b 100644
--- a/src/host/trxcon/src/l1ctl.c
+++ b/src/host/trxcon/src/l1ctl.c
@@ -44,7 +44,7 @@
 #include <osmocom/bb/trxcon/trxcon.h>
 #include <osmocom/bb/trxcon/trxcon_fsm.h>
-#define L1CTL_LENGTH		256
+#define L1CTL_LENGTH		512
 #define L1CTL_HEADROOM		32
/* Logging categories configurable via trxcon_set_log_cfg() */
diff --git a/src/host/trxcon/src/sched_lchan_common.c b/src/host/trxcon/src/sched_lchan_common.c
index 2308297..2b1729a 100644
--- a/src/host/trxcon/src/sched_lchan_common.c
+++ b/src/host/trxcon/src/sched_lchan_common.c
@@ -78,13 +78,12 @@
  * Examples: "  ****.." (incomplete, 4/6 bursts)
  *           "    ****" (complete, all 4 bursts)
  *           "**.***.." (incomplete, 5/8 bursts) */
-const char *l1sched_burst_mask2str(const uint8_t *mask, int bits)
+const char *l1sched_burst_mask2str(const uint32_t *mask, int bits)
 {
-	/* TODO: CSD is interleaved over 22 bursts, so the mask needs to be extended */
-	static char buf[8 + 1];
+	static char buf[32 + 1];
    char *ptr = buf;
-	OSMO_ASSERT(bits <= 8 && bits > 0);
+	OSMO_ASSERT(bits <= 32 && bits > 0);
while (--bits >= 0)
    	*(ptr++) = (*mask & (1 << bits)) ? '*' : '.';
diff --git a/src/host/trxcon/src/sched_lchan_desc.c b/src/host/trxcon/src/sched_lchan_desc.c
index 4943a71..db5446e 100644
--- a/src/host/trxcon/src/sched_lchan_desc.c
+++ b/src/host/trxcon/src/sched_lchan_desc.c
@@ -130,7 +130,7 @@
    	 *
    	 * The MS shall continuously transmit bursts, even if there is nothing
    	 * to send, unless DTX (Discontinuous Transmission) is used. */
-		.burst_buf_size = 8 * GSM_NBITS_NB_GMSK_PAYLOAD,
+		.burst_buf_size = 24 * GSM_NBITS_NB_GMSK_PAYLOAD,
    	.rx_fn = rx_tchf_fn,
    	.tx_fn = tx_tchf_fn,
    },
@@ -156,7 +156,7 @@
    	 *
    	 * The MS shall continuously transmit bursts, even if there is nothing
    	 * to send, unless DTX (Discontinuous Transmission) is used. */
-		.burst_buf_size = 6 * GSM_NBITS_NB_GMSK_PAYLOAD,
+		.burst_buf_size = 24 * GSM_NBITS_NB_GMSK_PAYLOAD,
    	.rx_fn = rx_tchh_fn,
    	.tx_fn = tx_tchh_fn,
    },
@@ -167,7 +167,7 @@
    	.link_id = L1SCHED_CH_LID_DEDIC,
/* Same as for L1SCHED_TCHH_0, see above. */
-		.burst_buf_size = 6 * GSM_NBITS_NB_GMSK_PAYLOAD,
+		.burst_buf_size = 24 * GSM_NBITS_NB_GMSK_PAYLOAD,
    	.rx_fn = rx_tchh_fn,
    	.tx_fn = tx_tchh_fn,
    },
diff --git a/src/host/trxcon/src/sched_lchan_pdtch.c b/src/host/trxcon/src/sched_lchan_pdtch.c
index 001a2d9..0f8a25f 100644
--- a/src/host/trxcon/src/sched_lchan_pdtch.c
+++ b/src/host/trxcon/src/sched_lchan_pdtch.c
@@ -36,10 +36,11 @@
 int rx_pdtch_fn(struct l1sched_lchan_state *lchan,
    	const struct l1sched_burst_ind *bi)
 {
-	uint8_t l2[GPRS_L2_MAX_LEN], *mask;
+	uint8_t l2[GPRS_L2_MAX_LEN];
    int n_errors, n_bits_total, rc;
    sbit_t *bursts_p, *burst;
    size_t l2_len;
+	uint32_t *mask;
/* Set up pointers */
    mask = &lchan->rx_burst_mask;
@@ -125,7 +126,7 @@
 {
    ubit_t *bursts_p, *burst;
    const uint8_t *tsc;
-	uint8_t *mask;
+	uint32_t *mask;
    int rc;
/* Set up pointers */
diff --git a/src/host/trxcon/src/sched_lchan_tchf.c b/src/host/trxcon/src/sched_lchan_tchf.c
index 12bea57..ac9ee6b 100644
--- a/src/host/trxcon/src/sched_lchan_tchf.c
+++ b/src/host/trxcon/src/sched_lchan_tchf.c
@@ -3,7 +3,7 @@
  * TDMA scheduler: handlers for DL / UL bursts on logical channels
  *
  * (C) 2017-2022 by Vadim Yanitskiy axilirator@gmail.com
- * Contributions by sysmocom - s.f.m.c. GmbH
+ * (C) 2021-2023 by sysmocom - s.f.m.c. GmbH info@sysmocom.de
  *
  * All Rights Reserved
  *
@@ -28,6 +28,7 @@
#include <osmocom/gsm/protocol/gsm_04_08.h>
 #include <osmocom/gsm/gsm_utils.h>
+#include <osmocom/gsm/gsm0502.h>
#include <osmocom/coding/gsm0503_coding.h>
 #include <osmocom/coding/gsm0503_amr_dtx.h>
@@ -36,6 +37,16 @@
 #include <osmocom/bb/l1sched/l1sched.h>
 #include <osmocom/bb/l1sched/logging.h>
+/* Burst Payload LENgth (short alias) */
+#define BPLEN GSM_NBITS_NB_GMSK_PAYLOAD
+
+/* Burst BUFfer capacity (in BPLEN units) */
+#define BUFMAX 24
+
+/* Burst BUFfer position macros */
+#define BUFPOS(buf, n) &buf[(n) * BPLEN]
+#define BUFTAIL8(buf) BUFPOS(buf, (BUFMAX - 8))
+
 /* 3GPP TS 45.009, table 3.2.1.3-{1,3}: AMR on Downlink TCH/F.
  *
  * +---+---+---+---+---+---+---+---+
@@ -57,14 +68,34 @@
    [17] = 1, /* TCH/F: a=17 */
 };
+static int decode_fr_facch(struct l1sched_lchan_state *lchan)
+{
+	uint8_t data[GSM_MACBLOCK_LEN];
+	int n_errors, n_bits_total;
+	int rc;
+
+	rc = gsm0503_tch_fr_facch_decode(&data[0], BUFTAIL8(lchan->rx_bursts),
+					 &n_errors, &n_bits_total);
+	if (rc != GSM_MACBLOCK_LEN)
+		return rc;
+
+	/* calculate AVG of the measurements (FACCH/F takes 8 bursts) */
+	l1sched_lchan_meas_avg(lchan, 8);
+
+	l1sched_lchan_emit_data_ind(lchan, &data[0], GSM_MACBLOCK_LEN,
+				    n_errors, n_bits_total, false);
+
+	return GSM_MACBLOCK_LEN;
+}
+
 int rx_tchf_fn(struct l1sched_lchan_state *lchan,
           const struct l1sched_burst_ind *bi)
 {
    int n_errors = -1, n_bits_total = 0, rc;
    sbit_t *bursts_p, *burst;
-	uint8_t tch_data[128];
+	uint8_t tch_data[290];
    size_t tch_data_len;
-	uint8_t *mask;
+	uint32_t *mask;
    int amr = 0;
    uint8_t ft;
@@ -77,8 +108,8 @@
if (bi->bid == 0) {
    	/* Shift the burst buffer by 4 bursts leftwards */
-		memcpy(&bursts_p[0], &bursts_p[464], 464);
-		memset(&bursts_p[464], 0, 464);
+		memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 4), 20 * BPLEN);
+		memset(BUFPOS(bursts_p, 20), 0, 4 * BPLEN);
    	*mask = *mask << 4;
    } else {
    	/* Align to the first burst of a block */
@@ -92,8 +123,8 @@
    /* Store the measurements */
    l1sched_lchan_meas_push(lchan, bi);
-	/* Copy burst to end of buffer of 8 bursts */
-	burst = bursts_p + bi->bid * 116 + 464;
+	/* Copy burst to end of buffer of 24 bursts */
+	burst = BUFPOS(bursts_p, 20 + bi->bid);
    memcpy(burst, bi->burst + 3, 58);
    memcpy(burst + 58, bi->burst + 87, 58);
@@ -102,7 +133,7 @@
    	return 0;
/* Calculate AVG of the measurements */
-	l1sched_lchan_meas_avg(lchan, 8);
+	l1sched_lchan_meas_avg(lchan, 8); // XXX
/* Check for complete set of bursts */
    if ((*mask & 0xff) != 0xff) {
@@ -115,15 +146,18 @@
}
+	/* TCH/F: speech and signalling frames are interleaved over 8 bursts, while
+	 * CSD frames are interleaved over 22 bursts.  Unless we're in CSD mode,
+	 * decode only the last 8 bursts to avoid introducing additional delays. */
    switch (lchan->tch_mode) {
    case GSM48_CMODE_SIGN:
    case GSM48_CMODE_SPEECH_V1: /* FR */
-		rc = gsm0503_tch_fr_decode(&tch_data[0], bursts_p,
-			1, 0, &n_errors, &n_bits_total);
+		rc = gsm0503_tch_fr_decode(&tch_data[0], BUFTAIL8(bursts_p),
+					   1, 0, &n_errors, &n_bits_total);
    	break;
    case GSM48_CMODE_SPEECH_EFR: /* EFR */
-		rc = gsm0503_tch_fr_decode(&tch_data[0], bursts_p,
-			1, 1, &n_errors, &n_bits_total);
+		rc = gsm0503_tch_fr_decode(&tch_data[0], BUFTAIL8(bursts_p),
+					   1, 1, &n_errors, &n_bits_total);
    	break;
    case GSM48_CMODE_SPEECH_AMR: /* AMR */
    	/* we store tch_data + 2 header bytes, the amr variable set to
@@ -131,7 +165,7 @@
    	 * receive an FACCH frame instead of a voice frame (we do not
    	 * know this before we actually decode the frame) */
    	amr = 2;
-		rc = gsm0503_tch_afs_decode_dtx(&tch_data[amr], bursts_p,
+		rc = gsm0503_tch_afs_decode_dtx(&tch_data[amr], BUFTAIL8(bursts_p),
    					!sched_tchf_dl_amr_cmi_map[bi->fn % 26],
    					lchan->amr.codec,
    					lchan->amr.codecs,
@@ -156,6 +190,36 @@
    				    "osmo_amr_rtp_enc() returned rc=%d\n", rc);
    	}
    	break;
+	/* CSD (TCH/F14.4): 14.5 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_14k5:
+		/* FACCH/F does not steal TCH/F14.4 frames, but only disturbs some bits */
+		decode_fr_facch(lchan);
+		rc = gsm0503_tch_fr144_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+					      &n_errors, &n_bits_total);
+		break;
+	/* CSD (TCH/F9.6): 12.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_12k0:
+		/* FACCH/F does not steal TCH/F9.6 frames, but only disturbs some bits */
+		decode_fr_facch(lchan);
+		rc = gsm0503_tch_fr96_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+					     &n_errors, &n_bits_total);
+		break;
+	/* CSD (TCH/F4.8): 6.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_6k0:
+		/* FACCH/F does not steal TCH/F4.8 frames, but only disturbs some bits */
+		decode_fr_facch(lchan);
+		rc = gsm0503_tch_fr48_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+					     &n_errors, &n_bits_total);
+		break;
+	/* CSD (TCH/F2.4): 3.6 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_3k6:
+		/* TCH/F2.4 employs the same interleaving as TCH/FS (8 bursts),
+		 * so FACCH/F *does* steal TCH/F2.4 frames completely. */
+		if (decode_fr_facch(lchan) == GSM_MACBLOCK_LEN)
+			return 0; /* TODO: emit BFI? */
+		rc = gsm0503_tch_fr24_decode(&tch_data[0], BUFTAIL8(bursts_p),
+					     &n_errors, &n_bits_total);
+		break;
    default:
    	LOGP_LCHAND(lchan, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode);
    	return -EINVAL;
@@ -188,30 +252,13 @@
    				   n_errors, n_bits_total, true);
 }
-static struct msgb *prim_dequeue_tchf(struct l1sched_lchan_state *lchan)
-{
-	struct msgb *msg_facch;
-	struct msgb *msg_tch;
-
-	/* dequeue a pair of TCH and FACCH frames */
-	msg_tch = l1sched_lchan_prim_dequeue_tch(lchan, false);
-	msg_facch = l1sched_lchan_prim_dequeue_tch(lchan, true);
-
-	/* prioritize FACCH over TCH */
-	if (msg_facch != NULL) {
-		msgb_free(msg_tch); /* drop one TCH/FS block */
-		return msg_facch;
-	}
-
-	return msg_tch;
-}
-
 int tx_tchf_fn(struct l1sched_lchan_state *lchan,
           struct l1sched_burst_req *br)
 {
+	struct msgb *msg_facch, *msg_tch, *msg;
    ubit_t *bursts_p, *burst;
    const uint8_t *tsc;
-	uint8_t *mask;
+	uint32_t *mask;
    int rc;
/* Set up pointers */
@@ -225,11 +272,15 @@
    }
/* Shift the burst buffer by 4 bursts leftwards for interleaving */
-	memcpy(&bursts_p[0], &bursts_p[464], 464);
-	memset(&bursts_p[464], 0, 464);
+	memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 4), 20 * BPLEN);
+	memset(BUFPOS(bursts_p, 20), 0, 4 * BPLEN);
    *mask = *mask << 4;
-	struct msgb *msg = prim_dequeue_tchf(lchan);
+	/* dequeue a pair of TCH and FACCH frames */
+	msg_tch = l1sched_lchan_prim_dequeue_tch(lchan, false);
+	msg_facch = l1sched_lchan_prim_dequeue_tch(lchan, true);
+	/* prioritize FACCH over TCH */
+	msg = (msg_facch != NULL) ? msg_facch : msg_tch;
/* populate the buffer with bursts */
    switch (lchan->tch_mode) {
@@ -244,7 +295,7 @@
    		gsm0503_tch_fr_encode(bursts_p, NULL, 0, 1);
    		goto send_burst;
    	}
-		rc = gsm0503_tch_fr_encode(bursts_p,
+		rc = gsm0503_tch_fr_encode(BUFPOS(bursts_p, 0),
    				   msgb_l2(msg),
    				   msgb_l2len(msg), 1);
    	break;
@@ -268,7 +319,7 @@
    		data += 2;
    	}
-		rc = gsm0503_tch_afs_encode(bursts_p,
+		rc = gsm0503_tch_afs_encode(BUFPOS(bursts_p, 0),
    				    data, data_len,
    				    amr_fn_is_cmr,
    				    lchan->amr.codec,
@@ -277,6 +328,60 @@
    				    lchan->amr.ul_cmr);
    	break;
    }
+	/* CSD (TCH/F14.4): 14.5 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_14k5:
+		if ((msg = msg_tch) != NULL) {
+			OSMO_ASSERT(msgb_l2len(msg) == 290);
+			gsm0503_tch_fr144_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm data sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		} /* else: all bits of this frame are set to zero */
+		if ((msg = msg_facch) != NULL) {
+			gsm0503_tch_fr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm FACCH sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		}
+		goto send_burst;
+	/* CSD (TCH/F9.6): 12.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_12k0:
+		if ((msg = msg_tch) != NULL) {
+			OSMO_ASSERT(msgb_l2len(msg) == 4 * 60);
+			gsm0503_tch_fr96_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm data sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		} /* else: all bits of this frame are set to zero */
+		if ((msg = msg_facch) != NULL) {
+			gsm0503_tch_fr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm FACCH sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		}
+		goto send_burst;
+	/* CSD (TCH/F4.8): 6.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_6k0:
+		if ((msg = msg_tch) != NULL) {
+			OSMO_ASSERT(msgb_l2len(msg) == 2 * 60);
+			gsm0503_tch_fr48_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm data sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		} /* else: all bits of this frame are set to zero */
+		if ((msg = msg_facch) != NULL) {
+			gsm0503_tch_fr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm FACCH sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		}
+		goto send_burst;
+	/* CSD (TCH/F2.4): 3.6 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_3k6:
+		if (msg == NULL)
+			goto send_burst;
+		if (msg == msg_facch) {
+			/* FACCH/F does steal a TCH/F2.4 frame completely */
+			rc = gsm0503_tch_fr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+		} else {
+			OSMO_ASSERT(msgb_l2len(msg) == 2 * 36);
+			rc = gsm0503_tch_fr24_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+		}
+		break;
    default:
    	LOGP_LCHAND(lchan, LOGL_ERROR,
    		    "TCH mode %s is unknown or not supported\n",
@@ -288,16 +393,18 @@
    	LOGP_LCHAND(lchan, LOGL_ERROR, "Failed to encode L2 payload (len=%u): %s\n",
    		    msgb_l2len(msg), msgb_hexdump_l2(msg));
 free_bad_msg:
-		msgb_free(msg);
+		msgb_free(msg_facch);
+		msgb_free(msg_tch);
    	return -EINVAL;
    }
/* Confirm data / traffic sending (pass ownership of the msgb/prim) */
    l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+	msgb_free((msg == msg_facch) ? msg_tch : msg_facch);
send_burst:
    /* Determine which burst should be sent */
-	burst = bursts_p + br->bid * 116;
+	burst = BUFPOS(bursts_p, br->bid);
/* Update mask */
    *mask |= (1 << br->bid);
diff --git a/src/host/trxcon/src/sched_lchan_tchh.c b/src/host/trxcon/src/sched_lchan_tchh.c
index 38aef34..0932cce 100644
--- a/src/host/trxcon/src/sched_lchan_tchh.c
+++ b/src/host/trxcon/src/sched_lchan_tchh.c
@@ -4,7 +4,7 @@
  *
  * (C) 2018-2022 by Vadim Yanitskiy axilirator@gmail.com
  * (C) 2018 by Harald Welte laforge@gnumonks.org
- * Contributions by sysmocom - s.f.m.c. GmbH
+ * (C) 2020-2023 by sysmocom - s.f.m.c. GmbH info@sysmocom.de
  *
  * All Rights Reserved
  *
@@ -31,6 +31,7 @@
#include <osmocom/gsm/protocol/gsm_04_08.h>
 #include <osmocom/gsm/gsm_utils.h>
+#include <osmocom/gsm/gsm0502.h>
#include <osmocom/coding/gsm0503_coding.h>
 #include <osmocom/coding/gsm0503_amr_dtx.h>
@@ -39,6 +40,16 @@
 #include <osmocom/bb/l1sched/l1sched.h>
 #include <osmocom/bb/l1sched/logging.h>
+/* Burst Payload LENgth (short alias) */
+#define BPLEN GSM_NBITS_NB_GMSK_PAYLOAD
+
+/* Burst BUFfer capacity (in BPLEN units) */
+#define BUFMAX 24
+
+/* Burst BUFfer position macros */
+#define BUFPOS(buf, n) &buf[(n) * BPLEN]
+#define BUFTAIL8(buf) BUFPOS(buf, (BUFMAX - 8))
+
 /* 3GPP TS 45.009, table 3.2.1.3-{2,4}: AMR on Downlink TCH/H.
  *
  * +---+---+---+---+---+---+
@@ -123,6 +134,41 @@
    [7]  = 1, /* FACCH/H(1): B2(22,24,1,3,5,7) */
 };
+/* 3GPP TS 45.002, table 2 in clause 7: Mapping tables for TCH/H2.4 and TCH/H4.8.
+ *
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ * | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v |
+ * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+ *
+ * TCH/H(0): B0(0,2,4,6,8,10,13,15,17,19,21,23,0,2,4,6,8,10,13,15,17,19)
+ * TCH/H(1): B0(1,3,5,7,9,11,14,16,18,20,22,24,1,3,5,7,9,11,14,16,18,20)
+ * TCH/H(0): B1(8,10,13,15,17,19,21,23,0,2,4,6,8,10,13,15,17,19,21,23,0,2)
+ * TCH/H(1): B1(9,11,14,16,18,20,22,24,1,3,5,7,9,11,14,16,18,20,22,24,1,3)
+ * TCH/H(0): B2(17,19,21,23,0,2,4,6,8,10,13,15,17,19,21,23,0,2,4,6,8,10)
+ * TCH/H(1): B2(18,20,22,24,1,3,5,7,9,11,14,16,18,20,22,24,1,3,5,7,9,11)
+ *
+ * TDMA frame number of burst 'a' % 26 is the table index.
+ * This mapping is valid for both TCH/H(0) and TCH/H(1). */
+static const uint8_t sched_tchh_ul_csd_map[26] = {
+	[0]  = 1, /* TCH/H(0): B0(0  ... 19) */
+	[1]  = 1, /* TCH/H(1): B0(1  ... 20) */
+	[8]  = 1, /* TCH/H(0): B1(8  ... 2) */
+	[9]  = 1, /* TCH/H(1): B1(9  ... 3) */
+	[17] = 1, /* TCH/H(0): B2(17 ... 10) */
+	[18] = 1, /* TCH/H(1): B2(18 ... 11) */
+};
+
+/* TDMA frame number of burst 'v' % 26 is the table index.
+ * This mapping is valid for both TCH/H(0) and TCH/H(1). */
+static const uint8_t sched_tchh_dl_csd_map[26] = {
+	[19] = 1, /* TCH/H(0): B0(0  ... 19) */
+	[20] = 1, /* TCH/H(1): B0(1  ... 20) */
+	[2]  = 1, /* TCH/H(0): B1(8  ... 2) */
+	[3]  = 1, /* TCH/H(1): B1(9  ... 3) */
+	[10] = 1, /* TCH/H(0): B2(17 ... 10) */
+	[11] = 1, /* TCH/H(1): B2(18 ... 11) */
+};
+
 /**
  * Can a TCH/H block transmission be initiated / finished
  * on a given frame number and a given channel type?
@@ -180,14 +226,34 @@
    return false;
 }
+static int decode_hr_facch(struct l1sched_lchan_state *lchan)
+{
+	uint8_t data[GSM_MACBLOCK_LEN];
+	int n_errors, n_bits_total;
+	int rc;
+
+	rc = gsm0503_tch_hr_facch_decode(&data[0], BUFTAIL8(lchan->rx_bursts),
+					 &n_errors, &n_bits_total);
+	if (rc != GSM_MACBLOCK_LEN)
+		return rc;
+
+	/* calculate AVG of the measurements (FACCH/H takes 6 bursts) */
+	l1sched_lchan_meas_avg(lchan, 6);
+
+	l1sched_lchan_emit_data_ind(lchan, &data[0], GSM_MACBLOCK_LEN,
+				    n_errors, n_bits_total, false);
+
+	return GSM_MACBLOCK_LEN;
+}
+
 int rx_tchh_fn(struct l1sched_lchan_state *lchan,
           const struct l1sched_burst_ind *bi)
 {
    int n_errors = -1, n_bits_total = 0, rc;
    sbit_t *bursts_p, *burst;
-	uint8_t tch_data[128];
+	uint8_t tch_data[240];
    size_t tch_data_len;
-	uint8_t *mask;
+	uint32_t *mask;
    int amr = 0;
    uint8_t ft;
@@ -200,9 +266,8 @@
if (bi->bid == 0) {
    	/* Shift the burst buffer by 2 bursts leftwards */
-		memcpy(&bursts_p[0], &bursts_p[232], 232);
-		memcpy(&bursts_p[232], &bursts_p[464], 232);
-		memset(&bursts_p[464], 0, 232);
+		memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 2), 20 * BPLEN);
+		memset(BUFPOS(bursts_p, 20), 0, 2 * BPLEN);
    	*mask = *mask << 2;
    }
@@ -215,9 +280,6 @@
    	if (lchan->tch_mode == GSM48_CMODE_SIGN) {
    		if (!l1sched_tchh_facch_start(lchan->type, bi->fn, 0))
    			return 0;
-		} else { /* or TCH/H traffic frame */
-			if (!l1sched_tchh_traffic_start(lchan->type, bi->fn, 0))
-				return 0;
    	}
    }
@@ -227,8 +289,8 @@
    /* Store the measurements */
    l1sched_lchan_meas_push(lchan, bi);
-	/* Copy burst to the end of buffer of 6 bursts */
-	burst = bursts_p + bi->bid * 116 + 464;
+	/* Copy burst to the end of buffer of 24 bursts */
+	burst = BUFPOS(bursts_p, 20 + bi->bid);
    memcpy(burst, bi->burst + 3, 58);
    memcpy(burst + 58, bi->burst + 87, 58);
@@ -236,6 +298,28 @@
    if (bi->bid != 1)
    	return 0;
+	/* Wait for complete set of bursts */
+	switch (lchan->tch_mode) {
+	case GSM48_CMODE_SIGN:
+		/* FACCH/H is interleaved over 6 bursts */
+		if ((*mask & 0x3f) != 0x3f)
+			return 0;
+		break;
+	case GSM48_CMODE_DATA_6k0:
+	case GSM48_CMODE_DATA_3k6:
+		/* Data (CSD) is interleaved over 22 bursts */
+		if ((*mask & 0x3fffff) != 0x3fffff)
+			return 0;
+		if (!sched_tchh_dl_csd_map[bi->fn % 26])
+			return 0; /* CSD: skip decoding attempt, need 2 more bursts */
+		break;
+	default:
+		/* Speech is interleaved over 4 bursts */
+		if ((*mask & 0x0f) != 0x0f)
+			return 0;
+		break;
+	}
+
    /* Skip decoding attempt in case of FACCH/H */
    if (lchan->dl_ongoing_facch) {
    	/* Send BFI (DATA.ind without payload) for the 2nd stolen TCH frame */
@@ -245,17 +329,21 @@
    	return 0;
    }
+	/* TCH/H: speech and signalling frames are interleaved over 4 and 6 bursts,
+	 * respectively, while CSD frames are interleaved over 22 bursts.  Unless
+	 * we're in CSD mode, decode only the last 6 bursts to avoid introducing
+	 * additional delays. */
    switch (lchan->tch_mode) {
    case GSM48_CMODE_SIGN:
    case GSM48_CMODE_SPEECH_V1: /* HR */
-		rc = gsm0503_tch_hr_decode(&tch_data[0], bursts_p,
+		rc = gsm0503_tch_hr_decode(&tch_data[0], BUFTAIL8(bursts_p),
    				   !sched_tchh_dl_facch_map[bi->fn % 26],
    				   &n_errors, &n_bits_total);
    	break;
    case GSM48_CMODE_SPEECH_AMR: /* AMR */
    	/* See comment in function rx_tchf_fn() */
    	amr = 2;
-		rc = gsm0503_tch_ahs_decode_dtx(&tch_data[amr], bursts_p,
+		rc = gsm0503_tch_ahs_decode_dtx(&tch_data[amr], BUFTAIL8(bursts_p),
    					!sched_tchh_dl_facch_map[bi->fn % 26],
    					!sched_tchh_dl_amr_cmi_map[bi->fn % 26],
    					lchan->amr.codec,
@@ -281,6 +369,20 @@
    				    "osmo_amr_rtp_enc() returned rc=%d\n", rc);
    	}
    	break;
+	/* CSD (TCH/H4.8): 6.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_6k0:
+		/* FACCH/H does not steal TCH/H4.8 frames, but only disturbs some bits */
+		decode_hr_facch(lchan);
+		rc = gsm0503_tch_hr48_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+					     &n_errors, &n_bits_total);
+		break;
+	/* CSD (TCH/H2.4): 3.6 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_3k6:
+		/* FACCH/H does not steal TCH/H2.4 frames, but only disturbs some bits */
+		decode_hr_facch(lchan);
+		rc = gsm0503_tch_hr24_decode(&tch_data[0], BUFPOS(bursts_p, 0),
+					     &n_errors, &n_bits_total);
+		break;
    default:
    	LOGP_LCHAND(lchan, LOGL_ERROR, "Invalid TCH mode: %u\n", lchan->tch_mode);
    	return -EINVAL;
@@ -322,33 +424,13 @@
    				   n_errors, n_bits_total, true);
 }
-static struct msgb *prim_dequeue_tchh(struct l1sched_lchan_state *lchan, uint32_t fn)
-{
-	struct msgb *msg_facch;
-	struct msgb *msg_tch;
-
-	/* dequeue a pair of TCH and FACCH frames */
-	msg_tch = l1sched_lchan_prim_dequeue_tch(lchan, false);
-	if (l1sched_tchh_facch_start(lchan->type, fn, true))
-		msg_facch = l1sched_lchan_prim_dequeue_tch(lchan, true);
-	else
-		msg_facch = NULL;
-
-	/* prioritize FACCH over TCH */
-	if (msg_facch != NULL) {
-		msgb_free(msg_tch); /* drop 1st TCH/HS block */
-		return msg_facch;
-	}
-
-	return msg_tch;
-}
-
 int tx_tchh_fn(struct l1sched_lchan_state *lchan,
           struct l1sched_burst_req *br)
 {
+	struct msgb *msg_facch, *msg_tch, *msg;
    ubit_t *bursts_p, *burst;
    const uint8_t *tsc;
-	uint8_t *mask;
+	uint32_t *mask;
    int rc;
/* Set up pointers */
@@ -362,16 +444,23 @@
    }
if (*mask == 0x00) {
-		/* Align transmission of the first FACCH/H frame */
-		if (lchan->tch_mode == GSM48_CMODE_SIGN)
+		/* Align transmission of the first frame */
+		switch (lchan->tch_mode) {
+		case GSM48_CMODE_SIGN:
    		if (!l1sched_tchh_facch_start(lchan->type, br->fn, 1))
    			return 0;
+			break;
+		case GSM48_CMODE_DATA_6k0:
+		case GSM48_CMODE_DATA_3k6:
+			if (!sched_tchh_ul_csd_map[br->fn % 26])
+				return 0;
+			break;
+		}
    }
/* Shift the burst buffer by 2 bursts leftwards for interleaving */
-	memcpy(&bursts_p[0], &bursts_p[232], 232);
-	memcpy(&bursts_p[232], &bursts_p[464], 232);
-	memset(&bursts_p[464], 0, 232);
+	memmove(BUFPOS(bursts_p, 0), BUFPOS(bursts_p, 2), 20 * BPLEN);
+	memset(BUFPOS(bursts_p, 20), 0, 2 * BPLEN);
    *mask = *mask << 2;
/* If FACCH/H blocks are still pending */
@@ -381,7 +470,23 @@
    	goto send_burst;
    }
-	struct msgb *msg = prim_dequeue_tchh(lchan, br->fn);
+	switch (lchan->tch_mode) {
+	case GSM48_CMODE_DATA_6k0:
+	case GSM48_CMODE_DATA_3k6:
+		/* CSD: skip dequeueing/encoding, send 2 more bursts */
+		if (!sched_tchh_ul_csd_map[br->fn % 26])
+			goto send_burst;
+		break;
+	}
+
+	/* dequeue a pair of TCH and FACCH frames */
+	msg_tch = l1sched_lchan_prim_dequeue_tch(lchan, false);
+	if (l1sched_tchh_facch_start(lchan->type, br->fn, true))
+		msg_facch = l1sched_lchan_prim_dequeue_tch(lchan, true);
+	else
+		msg_facch = NULL;
+	/* prioritize FACCH over TCH */
+	msg = (msg_facch != NULL) ? msg_facch : msg_tch;
/* populate the buffer with bursts */
    switch (lchan->tch_mode) {
@@ -397,7 +502,7 @@
    		gsm0503_tch_hr_encode(bursts_p, NULL, 0);
    		goto send_burst;
    	}
-		rc = gsm0503_tch_hr_encode(bursts_p,
+		rc = gsm0503_tch_hr_encode(BUFPOS(bursts_p, 0),
    				   msgb_l2(msg),
    				   msgb_l2len(msg));
    	break;
@@ -421,7 +526,7 @@
    		data += 2;
    	}
-		rc = gsm0503_tch_ahs_encode(bursts_p,
+		rc = gsm0503_tch_ahs_encode(BUFPOS(bursts_p, 0),
    				    data, data_len,
    				    amr_fn_is_cmr,
    				    lchan->amr.codec,
@@ -430,6 +535,34 @@
    				    lchan->amr.ul_cmr);
    	break;
    }
+	/* CSD (TCH/H4.8): 6.0 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_6k0:
+		if ((msg = msg_tch) != NULL) {
+			OSMO_ASSERT(msgb_l2len(msg) == 4 * 60);
+			gsm0503_tch_hr48_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm data sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		} /* else: all bits of this frame are set to zero */
+		if ((msg = msg_facch) != NULL) {
+			gsm0503_tch_hr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm FACCH sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		}
+		goto send_burst;
+	/* CSD (TCH/H2.4): 3.6 kbit/s radio interface rate */
+	case GSM48_CMODE_DATA_3k6:
+		if ((msg = msg_tch) != NULL) {
+			OSMO_ASSERT(msgb_l2len(msg) == 4 * 36);
+			gsm0503_tch_hr24_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm data sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		} /* else: all bits of this frame are set to zero */
+		if ((msg = msg_facch) != NULL) {
+			gsm0503_tch_hr_facch_encode(BUFPOS(bursts_p, 0), msgb_l2(msg));
+			/* Confirm FACCH sending (pass ownership of the msgb/prim) */
+			l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+		}
+		goto send_burst;
    default:
    	LOGP_LCHAND(lchan, LOGL_ERROR,
    		    "TCH mode %s is unknown or not supported\n",
@@ -441,7 +574,8 @@
    	LOGP_LCHAND(lchan, LOGL_ERROR, "Failed to encode L2 payload (len=%u): %s\n",
    		    msgb_l2len(msg), msgb_hexdump_l2(msg));
 free_bad_msg:
-		msgb_free(msg);
+		msgb_free(msg_facch);
+		msgb_free(msg_tch);
    	return -EINVAL;
    }
@@ -450,10 +584,11 @@
/* Confirm data / traffic sending (pass ownership of the msgb/prim) */
    l1sched_lchan_emit_data_cnf(lchan, msg, br->fn);
+	msgb_free((msg == msg_facch) ? msg_tch : msg_facch);
send_burst:
    /* Determine which burst should be sent */
-	burst = bursts_p + br->bid * 116;
+	burst = BUFPOS(bursts_p, br->bid);
/* Update mask */
    *mask |= (1 << br->bid);
diff --git a/src/host/trxcon/src/sched_lchan_xcch.c b/src/host/trxcon/src/sched_lchan_xcch.c
index b3863d5..52b5d1e 100644
--- a/src/host/trxcon/src/sched_lchan_xcch.c
+++ b/src/host/trxcon/src/sched_lchan_xcch.c
@@ -36,9 +36,10 @@
 int rx_data_fn(struct l1sched_lchan_state *lchan,
           const struct l1sched_burst_ind *bi)
 {
-	uint8_t l2[GSM_MACBLOCK_LEN], *mask;
+	uint8_t l2[GSM_MACBLOCK_LEN];
    int n_errors, n_bits_total, rc;
    sbit_t *bursts_p, *burst;
+	uint32_t *mask;
/* Set up pointers */
    mask = &lchan->rx_burst_mask;
@@ -124,7 +125,7 @@
 {
    ubit_t *bursts_p, *burst;
    const uint8_t *tsc;
-	uint8_t *mask;
+	uint32_t *mask;
    int rc;
/* Set up pointers */
diff --git a/src/host/trxcon/src/sched_prim.c b/src/host/trxcon/src/sched_prim.c
index 2597d84..c4c80f8 100644
--- a/src/host/trxcon/src/sched_prim.c
+++ b/src/host/trxcon/src/sched_prim.c
@@ -36,7 +36,7 @@
 #include <osmocom/bb/l1sched/logging.h>
#define L1SCHED_PRIM_HEADROOM	64
-#define L1SCHED_PRIM_TAILROOM	64
+#define L1SCHED_PRIM_TAILROOM	512
osmo_static_assert(sizeof(struct l1sched_prim) <= L1SCHED_PRIM_HEADROOM, l1sched_prim_size);
-- 
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: I0d7389a9a5f7019b9316ab1c0115797ff54a0e41
Gerrit-Change-Number: 32922
Gerrit-PatchSet: 13
Gerrit-Owner: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: Hoernchen ewild@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: laforge laforge@osmocom.org
Gerrit-Reviewer: osmith osmith@sysmocom.de
Gerrit-Reviewer: pespin pespin@sysmocom.de
Gerrit-MessageType: merged



    

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[L] Change in osmocom-bb[master]: trxcon/l1sched: implement CSD scheduling support