libosmo-gprs/include/osmocom/gprs/rlcmac/rlc.h

277 lines
9.0 KiB
C

/* RLC block manipulation, 3GPP TS 44.060 */
#pragma once
#include <stdint.h>
#include <osmocom/core/endian.h>
#include <osmocom/gprs/rlcmac/coding_scheme.h>
#define RLC_GPRS_SNS 128 /* GPRS, must be power of 2 */
#define RLC_EGPRS_SNS 2048 /* EGPRS, must be power of 2 */
#define RLC_EGPRS_MAX_BSN_DELTA 512
#define RLC_MAX_SNS RLC_EGPRS_SNS
#define RLC_MAX_LEN 74 /* MCS-9 data unit */
struct gprs_rlcmac_rlc_li_field {
#if OSMO_IS_LITTLE_ENDIAN
uint8_t e:1,
m:1,
li:6;
uint8_t ll_pdu[0];
#elif OSMO_IS_BIG_ENDIAN
/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */
uint8_t li:6, m:1, e:1;
uint8_t ll_pdu[0];
#endif
} __attribute__ ((packed));
/* TS 44.060 10.2.2 Uplink RLC data block */
struct gprs_rlcmac_rlc_ul_data_header {
#if OSMO_IS_LITTLE_ENDIAN
uint8_t r:1,
si:1,
cv:4,
pt:2;
uint8_t ti:1,
tfi:5,
pi:1,
spare:1;
uint8_t e:1,
bsn:7;
#elif OSMO_IS_BIG_ENDIAN
/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */
uint8_t pt:2, cv:4, si:1, r:1;
uint8_t spare:1, pi:1, tfi:5, ti:1;
uint8_t bsn:7, e:1;
#endif
} __attribute__ ((packed));
/* TS 44.060 10.2.1 Downlink RLC data block */
struct gprs_rlcmac_rlc_dl_data_header {
#if OSMO_IS_LITTLE_ENDIAN
uint8_t usf:3,
s_p:1,
rrbp:2,
pt:2;
uint8_t fbi:1,
tfi:5,
pr:2;
uint8_t e:1,
bsn:7;
struct gprs_rlcmac_rlc_li_field lime[0];
#elif OSMO_IS_BIG_ENDIAN
/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */
uint8_t pt:2, rrbp:2, s_p:1, usf:3;
uint8_t pr:2, tfi:5, fbi:1;
uint8_t bsn:7, e:1;
struct gprs_rlcmac_rlc_li_field lime[0];
#endif
} __attribute__ ((packed));
struct gprs_rlcmac_rlc_li_field_egprs {
#if OSMO_IS_LITTLE_ENDIAN
uint8_t e:1,
li:7;
#elif OSMO_IS_BIG_ENDIAN
/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */
uint8_t li:7, e:1;
#endif
} __attribute__ ((packed));
static inline uint16_t mod_sns_half(void)
{
return (RLC_MAX_SNS / 2) - 1;
}
struct gprs_rlcmac_rlc_block_info {
unsigned int data_len; /* EGPRS: N2, GPRS: N2-2, N-2 */
unsigned int bsn;
unsigned int ti;
unsigned int e;
unsigned int cv; /* FBI == 1 <=> CV == 0 */
unsigned int pi;
unsigned int spb;
};
void gprs_rlcmac_rlc_block_info_init(struct gprs_rlcmac_rlc_block_info *rdbi, enum gprs_rlcmac_coding_scheme cs, bool with_padding, const unsigned int spb);
struct gprs_rlcmac_rlc_data_info {
enum gprs_rlcmac_coding_scheme cs;
unsigned int r;
unsigned int si;
unsigned int tfi;
unsigned int cps;
unsigned int rsb;
unsigned int usf;
unsigned int es_p;
unsigned int rrbp;
unsigned int pr;
unsigned int fbi;
uint8_t num_data_blocks; /* this can actually be only 0, 1, 2: enforced in gprs_rlcmac_rlc_data_header_init() */
unsigned int with_padding;
unsigned int data_offs_bits[2];
struct gprs_rlcmac_rlc_block_info block_info[2];
};
void gprs_rlcmac_rlc_data_info_init_ul(struct gprs_rlcmac_rlc_data_info *rlc,
enum gprs_rlcmac_coding_scheme cs,
bool with_padding, unsigned int spb);
void gprs_rlcmac_rlc_data_info_init_dl(struct gprs_rlcmac_rlc_data_info *rlc,
enum gprs_rlcmac_coding_scheme cs,
bool with_padding);
/*
* EGPRS resegment status information for UL
* When only first split block is received bsn state
* will be set to EGPRS_RESEG_FIRST_SEG_RXD and when
* only second segment is received the state will be
* set to EGPRS_RESEG_SECOND_SEG_RXD. When both Split
* blocks are received the state will be set to
* EGPRS_RESEG_DEFAULT
* The EGPRS resegmentation feature allows MS to retransmit
* RLC blocks of HeaderType1, HeaderType2 by segmenting
* them to 2 HeaderType3 blocks(Example MCS5 will be
* retransmitted as 2 MCS2 blocks). Table 10.4.8b.1 of 44.060
* explains the possible values of SPB in HeadrType3 for UL
* direction. When the MCS is changed at the PCU, PCU directs the
* changed MCS to MS by PUAN or UPLINK ASSIGNMENT message along
* with RESEGMENT flag, Then MS may decide to retransmit the
* blocks by resegmenting it based on Table 8.1.1.1 of 44.060.
* The retransmission MCS is calculated based on current MCS of
* the Block and demanded MCS by PCU. Section 10.3a.4.3 of 44.060
* shows the HeadrType3 with SPB field present in it
*/
enum gprs_rlcmac_rlc_egprs_dl_reseg_bsn_state {
GPRS_RLCMAC_EGPRS_RESEG_DEFAULT = 0,
GPRS_RLCMAC_EGPRS_RESEG_FIRST_SEG_RXD = 0x01,
GPRS_RLCMAC_EGPRS_RESEG_SECOND_SEG_RXD = 0x02,
GPRS_RLCMAC_EGPRS_RESEG_INVALID = 0x04
};
/*
* EGPRS resegment status information for DL
* When only first segment is sent, bsn state
* will be set to EGPRS_RESEG_FIRST_SEG_SENT and when
* second segment is sent the state will be
* set to EGPRS_RESEG_SECOND_SEG_SENT.
* EGPRS_RESEG_DL_INVALID is set to 8 considering there is a scope for
* 3rd segment according to Table 10.4.8b.2 of 44.060
* The EGPRS resegmentation feature allows PCU to retransmit
* RLC blocks of HeaderType1, HeaderType2 by segmenting
* them to 2 HeaderType3 blocks(Example MCS5 will be
* retransmitted as 2 MCS2 blocks). Table 10.4.8b.2 of 44.060
* explains the possible values of SPB in HeadrType3 for DL
* direction.The PCU decides to retransmit the
* blocks by resegmenting it based on Table 8.1.1.1 of 44.060.
* The retransmission MCS is calculated based on current MCS of
* the Block and demanded MCS by PCU. Section 10.3a.3.3 of 44.060
* shows the HeadrType3 with SPB field present in it
*/
enum gprs_rlcmac_rlc_egprs_ul_reseg_bsn_state {
GPRS_RLCMAC_EGPRS_RESEG_UL_DEFAULT = 0,
GPRS_RLCMAC_EGPRS_RESEG_FIRST_SEG_SENT = 0x01,
GPRS_RLCMAC_EGPRS_RESEG_SECOND_SEG_SENT = 0x02,
GPRS_RLCMAC_EGPRS_RESEG_UL_INVALID = 0x08
};
/* holds the current status of the block w.r.t UL/DL split blocks */
union split_block_status {
enum gprs_rlcmac_rlc_egprs_ul_reseg_bsn_state block_status_ul;
enum gprs_rlcmac_rlc_egprs_dl_reseg_bsn_state block_status_dl;
};
/* Table 10.4.8b.2 of 44.060 */
enum gprs_rlcmac_rlc_egprs_ul_spb {
GPRS_RLCMAC_EGPRS_UL_SPB_NO_RETX = 0,
GPRS_RLCMAC_EGPRS_UL_SPB_FIRST_SEG_10PAD = 1,
GPRS_RLCMAC_EGPRS_UL_SPB_FIRST_SEG_6NOPAD = 2,
GPRS_RLCMAC_EGPRS_UL_SPB_SEC_SEG = 3,
};
#if 0
/* Table 10.4.8b.2 of 44.060 */
enum gprs_rlcmac_rlc_egprs_dl_spb {
GPRS_RLCMAC_EGPRS_DL_SPB_NO_RETX = 0,
GPRS_RLCMAC_EGPRS_DL_SPB_FIRST_SEG = 2,
GPRS_RLCMAC_EGPRS_DL_SPB_SEC_SEG = 3,
};
#endif
/*
* Valid puncturing scheme values
* TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1
*/
enum gprs_rlcmac_egprs_puncturing_values {
GPRS_RLCMAC_EGPRS_PS_1,
GPRS_RLCMAC_EGPRS_PS_2,
GPRS_RLCMAC_EGPRS_PS_3,
GPRS_RLCMAC_EGPRS_PS_INVALID,
};
/*
* EGPRS_MAX_PS_NUM_2 is valid for MCS 1,2,5,6.
* And EGPRS_MAX_PS_NUM_3 is valid for MCS 3,4,7,8,9
* TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1
*/
enum gprs_rlcmac_egprs_puncturing_types {
GPRS_RLCMAC_EGPRS_MAX_PS_NUM_2 = 2,
GPRS_RLCMAC_EGPRS_MAX_PS_NUM_3,
GPRS_RLCMAC_EGPRS_MAX_PS_NUM_INVALID,
};
struct gprs_rlcmac_rlc_block {
/* block data including LI headers */
uint8_t buf[RLC_MAX_LEN];
/* block data len including LI headers*/
uint8_t len;
struct gprs_rlcmac_rlc_block_info block_info;
/*
* cs_current_trans is variable to hold the cs_last value for
* current transmission. cs_current_trans is same as cs_last during
* transmission case. during retransmission cs_current_trans is
* fetched from egprs_mcs_retx_tbl table based on
* cs and demanded cs.reference is 44.060 Table
* 8.1.1.1 and Table 8.1.1.2
* For UL. cs_last shall be used everywhere.
*/
enum gprs_rlcmac_coding_scheme cs_current_trans;
enum gprs_rlcmac_coding_scheme cs_last;
/*
* The MCS of initial transmission of a BSN
* This variable is used for split block
* processing in DL
*/
enum gprs_rlcmac_coding_scheme cs_init;
/* puncturing scheme value to be used for next transmission*/
enum gprs_rlcmac_egprs_puncturing_values next_ps;
/* holds the status of the block w.r.t UL/DL split blocks*/
union split_block_status spb_status;
};
uint8_t *gprs_rlcmac_rlc_block_prepare(struct gprs_rlcmac_rlc_block *blk, size_t block_data_len);
/*
* I hold the currently transferred blocks and will provide
* the routines to manipulate these arrays.
*/
struct gprs_rlcmac_rlc_block_store {
struct gprs_rlcmac_rlc_block blocks[RLC_MAX_SNS/2];
};
struct gprs_rlcmac_rlc_block_store *gprs_rlcmac_rlc_block_store_alloc(void *ctx);
void gprs_rlcmac_rlc_block_store_free(struct gprs_rlcmac_rlc_block_store *blkst);
struct gprs_rlcmac_rlc_block *gprs_rlcmac_rlc_block_store_get_block(struct gprs_rlcmac_rlc_block_store *blkst, int bsn);
unsigned int gprs_rlcmac_rlc_mcs_cps(enum gprs_rlcmac_coding_scheme cs,
enum gprs_rlcmac_egprs_puncturing_values punct,
enum gprs_rlcmac_egprs_puncturing_values punct2,
bool with_padding);
enum gprs_rlcmac_egprs_puncturing_values gprs_rlcmac_get_punct_scheme(enum gprs_rlcmac_egprs_puncturing_values punct,
enum gprs_rlcmac_coding_scheme cs,
enum gprs_rlcmac_coding_scheme cs_current_trans,
enum gprs_rlcmac_rlc_egprs_ul_spb spb);
void gprs_rlcmac_update_punct_scheme(enum gprs_rlcmac_egprs_puncturing_values *punct,
enum gprs_rlcmac_coding_scheme cs);