[L] Change in osmocom-bb[master]: l1gprs: implement TBF starting time support - gerrit-log

24 Aug 2023

pespin has submitted this change. ( https://gerrit.osmocom.org/c/osmocom-bb/+/33223 )
Change subject: l1gprs: implement TBF starting time support
......................................................................
l1gprs: implement TBF starting time support
Change-Id: I174e3c43d2f4c828a528710b284e62c9bb794122
Related: OS#5500
---
M include/l1gprs.h
M src/shared/l1gprs.c
2 files changed, 256 insertions(+), 20 deletions(-)
Approvals:
  Jenkins Builder: Verified
  pespin: Looks good to me, approved

diff --git a/include/l1gprs.h b/include/l1gprs.h
index 060366e..eb15726 100644
--- a/include/l1gprs.h
+++ b/include/l1gprs.h
@@ -9,6 +9,21 @@
 struct l1gprs_state;
 struct msgb;
+struct l1gprs_tbf_pending_req {
+	/*! Item in l1gprs_state->tbf_list_pending */
+	struct llist_head list;
+	/*! Uplink or Downlink */
+	bool uplink;
+	/*! TBF reference number (not index) */
+	uint8_t tbf_ref;
+	/*! PDCH timeslots used by this TBF */
+	uint8_t slotmask;
+	/*! (Downlink only) DL TFI (Temporary Flow Indentity): 0..31 */
+	uint8_t dl_tfi;
+	/*! TBF starting time (absolute TDMA Fn) */
+	uint32_t start_fn;
+};
+
 struct l1gprs_tbf {
    /*! Item in l1gprs_state->tbf_list */
    struct llist_head list;
@@ -33,11 +48,16 @@
    uint8_t dl_tbf_count;
    /*! DL TFI mask */
    uint32_t dl_tfi_mask;
+	/*! Pending UL TBF count */
+	uint8_t pending_ul_tbf_count;
+	/*! Pending DL TBF count */
+	uint8_t pending_dl_tbf_count;
 };
static inline size_t l1gprs_pdch_use_count(const struct l1gprs_pdch *pdch)
 {
-	return pdch->ul_tbf_count + pdch->dl_tbf_count;
+	return pdch->ul_tbf_count + pdch->dl_tbf_count +
+	       pdch->pending_ul_tbf_count + pdch->pending_dl_tbf_count;
 }
@@ -46,8 +66,10 @@
 struct l1gprs_state {
    /*! PDCH state for each timeslot */
    struct l1gprs_pdch pdch[8];
-	/*! Uplink and Downlink TBFs */
+	/*! Uplink and Downlink TBFs (active), struct l1gprs_pending_tbf */
    struct llist_head tbf_list;
+	/*! Uplink and Downlink TBFs (pending), struct l1gprs_tbf_pending_req */
+	struct llist_head tbf_list_pending;
    /*! Logging context (used as prefix for messages) */
    char *log_prefix;
    /*! Some private data for API user */
diff --git a/src/shared/l1gprs.c b/src/shared/l1gprs.c
index bae13d2..a9a6228 100644
--- a/src/shared/l1gprs.c
+++ b/src/shared/l1gprs.c
@@ -31,6 +31,7 @@
#include <osmocom/gsm/protocol/gsm_04_08.h>
 #include <osmocom/gsm/protocol/gsm_44_060.h>
+#include <osmocom/gsm/gsm0502.h>
#include <osmocom/bb/l1ctl_proto.h>
 #include <osmocom/bb/l1gprs.h>
@@ -43,10 +44,16 @@
    LOGP_GPRS((pdch)->gprs, level, "(PDCH-%u) " fmt, \
    	  (pdch)->tn, ## args)
+#define LOG_TBF_CFG_REQ_FMT "tbf_ref=%u, slotmask=0x%02x, start_fn=%u"
+#define LOG_TBF_CFG_REQ_ARGS(req) \
+	(req)->tbf_ref, (req)->slotmask, ntohl((req)->start_fn)
+
 #define LOG_TBF_FMT "%cL-TBF#%03d"
 #define LOG_TBF_ARGS(tbf) \
    (tbf)->uplink ? 'U' : 'D', tbf->tbf_ref
+#define TDMA_FN_INVALID 0xffffffff
+
 static int l1gprs_log_cat = DLGLOBAL;
enum gprs_rlcmac_block_type {
@@ -56,13 +63,39 @@
    GPRS_RLCMAC_RESERVED		= 0x03,
 };
-static struct l1gprs_tbf *l1gprs_tbf_alloc(struct l1gprs_state *gprs,
+static struct l1gprs_tbf_pending_req *l1gprs_tbf_pending_req_alloc(void *talloc_ctx,
+						       bool uplink, uint8_t tbf_ref,
+						       uint8_t slotmask, uint32_t start_fn)
+{
+	struct l1gprs_tbf_pending_req *preq;
+
+	preq = talloc(talloc_ctx, struct l1gprs_tbf_pending_req);
+	OSMO_ASSERT(preq != NULL);
+
+	preq->uplink = uplink;
+	preq->tbf_ref = tbf_ref;
+	preq->slotmask = slotmask;
+	preq->start_fn = start_fn;
+
+	return preq;
+}
+
+static void l1gprs_tbf_pending_req_free(struct l1gprs_tbf_pending_req *preq)
+{
+	if (preq == NULL)
+		return;
+	llist_del(&preq->list);
+	talloc_free(preq);
+}
+
+
+static struct l1gprs_tbf *l1gprs_tbf_alloc(void *talloc_ctx,
    				   bool uplink, uint8_t tbf_ref,
    				   uint8_t slotmask)
 {
    struct l1gprs_tbf *tbf;
-	tbf = talloc(gprs, struct l1gprs_tbf);
+	tbf = talloc(talloc_ctx, struct l1gprs_tbf);
    OSMO_ASSERT(tbf != NULL);
tbf->uplink = uplink;
@@ -80,12 +113,12 @@
    talloc_free(tbf);
 }
-static struct l1gprs_tbf *l1gprs_find_tbf(struct l1gprs_state *gprs,
-					  bool uplink, uint8_t tbf_ref)
+static struct l1gprs_tbf *_l1gprs_find_tbf(const struct llist_head *tbf_list,
+					   bool uplink, uint8_t tbf_ref)
 {
    struct l1gprs_tbf *tbf;
-	llist_for_each_entry(tbf, &gprs->tbf_list, list) {
+	llist_for_each_entry(tbf, tbf_list, list) {
    	if (tbf->uplink != uplink)
    		continue;
    	if (tbf->tbf_ref != tbf_ref)
@@ -96,6 +129,16 @@
    return NULL;
 }
+static struct l1gprs_tbf *l1gprs_find_tbf(struct l1gprs_state *gprs,
+					  bool uplink, uint8_t tbf_ref)
+{
+	struct l1gprs_tbf *tbf;
+
+	if ((tbf = _l1gprs_find_tbf(&gprs->tbf_list, uplink, tbf_ref)) != NULL)
+		return tbf;
+	return NULL;
+}
+
 static void l1gprs_register_tbf(struct l1gprs_state *gprs,
    			struct l1gprs_tbf *tbf)
 {
@@ -129,7 +172,7 @@
    llist_add_tail(&tbf->list, &gprs->tbf_list);
LOGP_GPRS(gprs, LOGL_INFO,
-		  LOG_TBF_FMT " is registered\n",
+		  LOG_TBF_FMT " is registered as active\n",
    	  LOG_TBF_ARGS(tbf));
 }
@@ -228,6 +271,122 @@
    l1gprs_tbf_free(tbf);
 }
+static void l1gprs_add_tbf_pending_req(struct l1gprs_state *gprs, struct l1gprs_tbf_pending_req *preq)
+{
+	OSMO_ASSERT(preq->slotmask != 0x00);
+
+	/* Update the PDCH states */
+	for (unsigned int tn = 0; tn < ARRAY_SIZE(gprs->pdch); tn++) {
+		struct l1gprs_pdch *pdch = &gprs->pdch[tn];
+
+		if (~preq->slotmask & (1 << pdch->tn))
+			continue;
+
+		if (preq->uplink) {
+			pdch->pending_ul_tbf_count++;
+		} else {
+			pdch->pending_dl_tbf_count++;
+			/* We don't care about DL_TFI here, we don't want to activate it */
+		}
+
+		LOGP_PDCH(pdch, LOGL_DEBUG,
+			  "Linked " LOG_TBF_FMT "\n",
+			  LOG_TBF_ARGS(preq));
+		/* If just got first use: */
+		if (l1gprs_pdch_use_count(pdch) == 1) {
+			if (gprs->pdch_changed_cb)
+				gprs->pdch_changed_cb(pdch, true);
+		}
+	}
+
+	llist_add_tail(&preq->list, &gprs->tbf_list_pending);
+
+	LOGP_GPRS(gprs, LOGL_INFO,
+		  LOG_TBF_FMT " is added as pending (fn=%u)\n",
+		  LOG_TBF_ARGS(preq), preq->start_fn);
+}
+
+static void l1gprs_remove_tbf_pending_req(struct l1gprs_state *gprs, struct l1gprs_tbf_pending_req *preq)
+{
+
+	OSMO_ASSERT(preq->slotmask != 0x00);
+
+	/* Update the PDCH states */
+	for (unsigned int tn = 0; tn < ARRAY_SIZE(gprs->pdch); tn++) {
+		struct l1gprs_pdch *pdch = &gprs->pdch[tn];
+
+		if (~preq->slotmask & (1 << pdch->tn))
+			continue;
+
+		if (preq->uplink) {
+			OSMO_ASSERT(pdch->pending_ul_tbf_count > 0);
+			pdch->pending_ul_tbf_count--;
+		} else {
+			OSMO_ASSERT(pdch->pending_dl_tbf_count > 0);
+			pdch->pending_dl_tbf_count--;
+			/* We don't care about DL_TFI here, we didn't activate them in first place */
+		}
+
+		LOGP_PDCH(pdch, LOGL_DEBUG,
+			  "Unlinked " LOG_TBF_FMT "\n",
+			  LOG_TBF_ARGS(preq));
+		/* Note: not calling gprs->pdch_changed_cb since no real
+		 * activate / deactivate change can occur on lower layers as a
+		 * consequence of moving a PDCH from pending to active, hence
+		 * avoid triggering one active=false event here and immediately
+		 * afterwards the opposite event when adding it as active: */
+	}
+
+	llist_del(&preq->list);
+
+	LOGP_GPRS(gprs, LOGL_INFO,
+		  LOG_TBF_FMT " is removed as pending (fn=%u)\n",
+		  LOG_TBF_ARGS(preq), preq->start_fn);
+}
+
+/* Check if the current TDMA Fn is past the start TDMA Fn.
+ * Based on fn_cmp() implementation from osmo-pcu.git, simplified. */
+static bool l1gprs_check_fn(uint32_t current, uint32_t start)
+{
+	const uint32_t thresh = GSM_TDMA_HYPERFRAME / 2;
+
+	if ((current < start && (start - current) < thresh) ||
+	    (current > start && (current - start) > thresh))
+		return false;
+
+	return true;
+}
+
+/* Check the list of pending TBFs and move those with expired Fn to the active list */
+static void l1gprs_check_pending_tbfs(struct l1gprs_state *gprs, uint32_t fn)
+{
+	struct l1gprs_tbf_pending_req *preq, *tmp;
+	struct l1gprs_tbf *tbf;
+
+	llist_for_each_entry_safe(preq, tmp, &gprs->tbf_list_pending, list) {
+		if (!l1gprs_check_fn(fn, preq->start_fn))
+			continue;
+
+		LOGP_GPRS(gprs, LOGL_INFO,
+			  LOG_TBF_FMT " becomes active (current_fn=%u, start_fn=%u)\n",
+			  LOG_TBF_ARGS(preq), fn, preq->start_fn);
+
+		l1gprs_remove_tbf_pending_req(gprs, preq);
+
+		/* If this tbf already exists in the main list, simply update its timeslot: */
+		tbf = _l1gprs_find_tbf(&gprs->tbf_list, preq->uplink, preq->tbf_ref);
+		if (tbf) {
+			l1gprs_update_tbf(gprs, tbf, preq->slotmask);
+			tbf->dl_tfi = preq->dl_tfi;
+		} else {
+			tbf = l1gprs_tbf_alloc(gprs, preq->uplink, preq->tbf_ref, preq->slotmask);
+			tbf->dl_tfi = preq->dl_tfi;
+			l1gprs_register_tbf(gprs, tbf);
+		}
+		talloc_free(preq);
+	}
+}
+
 #define L1GPRS_L1CTL_MSGB_SIZE		256
 #define L1GPRS_L1CTL_MSGB_HEADROOM	32
@@ -302,6 +461,7 @@
    }
INIT_LLIST_HEAD(&gprs->tbf_list);
+	INIT_LLIST_HEAD(&gprs->tbf_list_pending);
if (log_prefix == NULL)
    	gprs->log_prefix = talloc_asprintf(gprs, "l1gprs[0x%p]: ", gprs);
@@ -327,6 +487,16 @@
    	l1gprs_tbf_free(tbf);
    }
+	while (!llist_empty(&gprs->tbf_list_pending)) {
+		struct l1gprs_tbf_pending_req *preq;
+
+		preq = llist_first_entry(&gprs->tbf_list_pending, struct l1gprs_tbf_pending_req, list);
+		LOGP_GPRS(gprs, LOGL_DEBUG,
+			  "%s(): " LOG_TBF_FMT " is free()d\n",
+			  __func__, LOG_TBF_ARGS(preq));
+		l1gprs_tbf_pending_req_free(preq);
+	}
+
    talloc_free(gprs->log_prefix);
    talloc_free(gprs);
 }
@@ -351,12 +521,23 @@
    }
LOGP_GPRS(gprs, LOGL_INFO,
-		  "Rx Uplink TBF config: tbf_ref=%u, slotmask=0x%02x\n",
-		  req->tbf_ref, req->slotmask);
-
-	tbf = l1gprs_find_tbf(gprs, true, req->tbf_ref);
+		  "Rx UL TBF config: " LOG_TBF_CFG_REQ_FMT "\n",
+		  LOG_TBF_CFG_REQ_ARGS(req));
if (req->slotmask != 0x00) {
+		uint32_t start_fn = ntohl(req->start_fn);
+		if (start_fn != TDMA_FN_INVALID) {
+			/* Create a temporary tbf and keep it in a separate
+			 * list. It will be moved/merged into the main list at
+			 * start_fn time. */
+			struct l1gprs_tbf_pending_req *preq;
+			preq = l1gprs_tbf_pending_req_alloc(gprs, true, req->tbf_ref,
+							     req->slotmask, start_fn);
+			l1gprs_add_tbf_pending_req(gprs, preq);
+			return 0;
+		}
+
+		tbf = l1gprs_find_tbf(gprs, true, req->tbf_ref);
    	if (tbf) {
    		l1gprs_update_tbf(gprs, tbf, req->slotmask);
    	} else {
@@ -364,6 +545,7 @@
    		l1gprs_register_tbf(gprs, tbf);
    	}
    } else {
+		tbf = l1gprs_find_tbf(gprs, true, req->tbf_ref);
    	if (tbf == NULL) {
    		LOGP_GPRS(gprs, LOGL_ERROR, "%s(): " LOG_TBF_FMT " not found\n",
    			  __func__, 'U', req->tbf_ref);
@@ -390,8 +572,8 @@
    }
LOGP_GPRS(gprs, LOGL_INFO,
-		  "Rx Downlink TBF config: tbf_ref=%u, slotmask=0x%02x, dl_tfi=%u\n",
-		  req->tbf_ref, req->slotmask, req->dl_tfi);
+		  "Rx DL TBF config: " LOG_TBF_CFG_REQ_FMT ", dl_tfi=%u\n",
+		  LOG_TBF_CFG_REQ_ARGS(req), req->dl_tfi);
if (req->dl_tfi > 31) {
    	LOGP_GPRS(gprs, LOGL_ERROR,
@@ -400,17 +582,31 @@
    	return -EINVAL;
    }
-	tbf = l1gprs_find_tbf(gprs, false, req->tbf_ref);
-
    if (req->slotmask != 0x00) {
+		uint32_t start_fn = ntohl(req->start_fn);
+		if (start_fn != TDMA_FN_INVALID) {
+			/* Create a temporary tbf and keep it in a separate
+			 * list. It will be moved/merged into the main list at
+			 * start_fn time. */
+			struct l1gprs_tbf_pending_req *preq;
+			preq = l1gprs_tbf_pending_req_alloc(gprs, false, req->tbf_ref,
+							    req->slotmask, start_fn);
+			preq->dl_tfi = req->dl_tfi;
+			l1gprs_add_tbf_pending_req(gprs, preq);
+			return 0;
+		}
+
+		tbf = l1gprs_find_tbf(gprs, false, req->tbf_ref);
    	if (tbf) {
    		l1gprs_update_tbf(gprs, tbf, req->slotmask);
    	} else {
-			tbf = l1gprs_tbf_alloc(gprs, false, req->tbf_ref, req->slotmask);
+			tbf = l1gprs_tbf_alloc(gprs, false, req->tbf_ref,
+					       req->slotmask);
    		tbf->dl_tfi = req->dl_tfi;
    		l1gprs_register_tbf(gprs, tbf);
    	}
    } else {
+		tbf = l1gprs_find_tbf(gprs, false, req->tbf_ref);
    	if (tbf == NULL) {
    		LOGP_GPRS(gprs, LOGL_ERROR, "%s(): " LOG_TBF_FMT " not found\n",
    			  __func__, 'D', req->tbf_ref);
@@ -496,9 +692,17 @@
    	  BLOCK_IND_IS_PTCCH(ind) ? "PTCCH" : "PDTCH",
    	  ind->hdr.fn, ind->data_len, osmo_hexdump(ind->data, ind->data_len));
-	if ((pdch->ul_tbf_count == 0) && (pdch->dl_tbf_count == 0)) {
-		LOGP_PDCH(pdch, LOGL_ERROR,
-			  "Rx DL BLOCK.ind, but this PDCH has no configured TBFs\n");
+	l1gprs_check_pending_tbfs(gprs, ind->hdr.fn);
+
+	if (pdch->ul_tbf_count + pdch->dl_tbf_count == 0) {
+		if (pdch->pending_ul_tbf_count + pdch->pending_dl_tbf_count > 0)
+			LOGP_PDCH(pdch, LOGL_DEBUG,
+				  "Rx DL BLOCK.ind (fn=%u), but this PDCH has no active TBFs yet\n",
+				  ind->hdr.fn);
+		else
+			LOGP_PDCH(pdch, LOGL_ERROR,
+				  "Rx DL BLOCK.ind (fn=%u), but this PDCH has no configured TBFs\n",
+				  ind->hdr.fn);
    	return NULL;
    }
-- 
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: I174e3c43d2f4c828a528710b284e62c9bb794122
Gerrit-Change-Number: 33223
Gerrit-PatchSet: 13
Gerrit-Owner: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria axilirator@gmail.com
Gerrit-Reviewer: pespin pespin@sysmocom.de
Gerrit-MessageType: merged



    