| /* |
| * Copyright (C) 2013 by Holger Hans Peter Freyther |
| * |
| * 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 2 |
| * 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. |
| */ |
| |
| #include "bts.h" |
| #include "gprs_debug.h" |
| #include <rlc.h> |
| |
| #include <stdbool.h> |
| #include <string.h> |
| #include <sys/types.h> |
| |
| extern "C" { |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/bitvec.h> |
| #include <osmocom/core/logging.h> |
| |
| #include "coding_scheme.h" |
| } |
| |
| |
| uint8_t *prepare(struct gprs_rlc_data *rlc, size_t block_data_len) |
| { |
| /* todo.. only set it once if it turns out to be a bottleneck */ |
| memset(rlc->block, 0x0, sizeof(rlc->block)); |
| memset(rlc->block, 0x2b, block_data_len); |
| |
| /* Initial value of puncturing scheme */ |
| rlc->next_ps = EGPRS_PS_1; |
| |
| return rlc->block; |
| } |
| |
| static void gprs_rlc_data_header_init(struct gprs_rlc_data_info *rlc, |
| enum CodingScheme cs, bool with_padding, unsigned int header_bits, |
| const unsigned int spb) |
| { |
| unsigned int i; |
| unsigned int padding_bits = with_padding ? mcs_opt_padding_bits(cs) : 0; |
| |
| rlc->cs = cs; |
| rlc->r = 0; |
| rlc->si = 0; |
| rlc->tfi = 0; |
| rlc->cps = 0; |
| rlc->rsb = 0; |
| rlc->usf = 0; |
| rlc->es_p = 0; |
| rlc->rrbp = 0; |
| rlc->pr = 0; |
| rlc->num_data_blocks = num_data_blocks(mcs_header_type(cs)); |
| rlc->with_padding = with_padding; |
| |
| OSMO_ASSERT(rlc->num_data_blocks <= ARRAY_SIZE(rlc->block_info)); |
| |
| for (i = 0; i < rlc->num_data_blocks; i++) { |
| gprs_rlc_data_block_info_init(&rlc->block_info[i], cs, |
| with_padding, spb); |
| |
| rlc->data_offs_bits[i] = |
| header_bits + padding_bits + |
| (i+1) * num_data_block_header_bits(mcs_header_type(cs)) + |
| i * 8 * rlc->block_info[0].data_len; |
| } |
| } |
| |
| void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, |
| enum CodingScheme cs, bool with_padding, const unsigned int spb) |
| { |
| OSMO_ASSERT(mcs_is_valid(cs)); |
| return gprs_rlc_data_header_init(rlc, cs, with_padding, |
| num_data_header_bits_DL(mcs_header_type(cs)), spb); |
| } |
| |
| void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, |
| enum CodingScheme cs, bool with_padding) |
| { |
| OSMO_ASSERT(mcs_is_valid(cs)); |
| /* |
| * last parameter is sent as 0 since common function used |
| * for both DL and UL |
| */ |
| return gprs_rlc_data_header_init(rlc, cs, with_padding, |
| num_data_header_bits_UL(mcs_header_type(cs)), 0); |
| } |
| |
| void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, |
| enum CodingScheme cs, bool with_padding, const unsigned int spb) |
| { |
| unsigned int data_len = mcs_max_data_block_bytes(cs); |
| if (with_padding) |
| data_len -= mcs_opt_padding_bits(cs) / 8; |
| |
| rdbi->data_len = data_len; |
| rdbi->bsn = 0; |
| rdbi->ti = 0; |
| rdbi->e = 1; |
| rdbi->cv = 15; |
| rdbi->pi = 0; |
| rdbi->spb = spb; |
| } |
| |
| unsigned int gprs_rlc_mcs_cps(enum CodingScheme cs, |
| enum egprs_puncturing_values punct, |
| enum egprs_puncturing_values punct2, bool with_padding) |
| { |
| /* validate that punct and punct2 are as expected */ |
| switch (cs) { |
| case MCS9: |
| case MCS8: |
| case MCS7: |
| if (punct2 == EGPRS_PS_INVALID) { |
| LOGP(DRLCMACDL, LOGL_ERROR, |
| "Invalid punct2 value for coding scheme %d: %d\n", |
| cs, punct2); |
| return -1; |
| } |
| /* fall through */ |
| case MCS6: |
| case MCS5: |
| case MCS4: |
| case MCS3: |
| case MCS2: |
| case MCS1: |
| if (punct == EGPRS_PS_INVALID) { |
| LOGP(DRLCMACDL, LOGL_ERROR, |
| "Invalid punct value for coding scheme %d: %d\n", |
| cs, punct); |
| return -1; |
| } |
| break; |
| default: |
| return -1; |
| } |
| |
| /* See 3GPP TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 */ |
| switch (cs) { |
| case MCS1: return 0b1011 + |
| punct % EGPRS_MAX_PS_NUM_2; |
| case MCS2: return 0b1001 + |
| punct % EGPRS_MAX_PS_NUM_2; |
| case MCS3: return (with_padding ? 0b0110 : 0b0011) + |
| punct % EGPRS_MAX_PS_NUM_3; |
| case MCS4: return 0b0000 + |
| punct % EGPRS_MAX_PS_NUM_3; |
| case MCS5: return 0b100 + |
| punct % EGPRS_MAX_PS_NUM_2; |
| case MCS6: return (with_padding ? 0b010 : 0b000) + |
| punct % EGPRS_MAX_PS_NUM_2; |
| case MCS7: return 0b10100 + |
| 3 * (punct % EGPRS_MAX_PS_NUM_3) + |
| punct2 % EGPRS_MAX_PS_NUM_3; |
| case MCS8: return 0b01011 + |
| 3 * (punct % EGPRS_MAX_PS_NUM_3) + |
| punct2 % EGPRS_MAX_PS_NUM_3; |
| case MCS9: return 0b00000 + |
| 4 * (punct % EGPRS_MAX_PS_NUM_3) + |
| punct2 % EGPRS_MAX_PS_NUM_3; |
| default: ; |
| } |
| |
| return -1; |
| } |
| |
| void gprs_rlc_mcs_cps_decode(unsigned int cps, |
| enum CodingScheme cs, int *punct, int *punct2, int *with_padding) |
| { |
| *punct2 = -1; |
| *with_padding = 0; |
| |
| switch (cs) { |
| case MCS1: |
| cps -= 0b1011; *punct = cps % 2; break; |
| case MCS2: |
| cps -= 0b1001; *punct = cps % 2; break; |
| case MCS3: |
| cps -= 0b0011; *punct = cps % 3; *with_padding = cps >= 3; break; |
| case MCS4: |
| cps -= 0b0000; *punct = cps % 3; break; |
| case MCS5: |
| cps -= 0b100; *punct = cps % 2; break; |
| case MCS6: |
| cps -= 0b000; *punct = cps % 2; *with_padding = cps >= 2; break; |
| case MCS7: |
| cps -= 0b10100; *punct = cps / 3; *punct2 = cps % 3; break; |
| case MCS8: |
| cps -= 0b01011; *punct = cps / 3; *punct2 = cps % 3; break; |
| case MCS9: |
| cps -= 0b00000; *punct = cps / 4; *punct2 = cps % 3; break; |
| default: ; |
| } |
| } |
| |
| /* |
| * Finds the PS value for retransmission with MCS change, |
| * retransmission with no MCS change, fresh transmission cases. |
| * The return value shall be used for current transmission only |
| * 44.060 9.3.2.1 defines the PS selection for MCS change case |
| * cs_current is the output of MCS selection algorithm for retx |
| * cs is coding scheme of previous transmission of RLC data block |
| */ |
| enum egprs_puncturing_values gprs_get_punct_scheme( |
| enum egprs_puncturing_values punct, |
| const enum CodingScheme &cs, |
| const enum CodingScheme &cs_current, |
| const enum egprs_rlcmac_dl_spb spb) |
| { |
| |
| /* |
| * 10.4.8b of TS 44.060 |
| * If it is second segment of the block |
| * dont change the puncturing scheme |
| */ |
| if (spb == EGPRS_RLCMAC_DL_SEC_SEG) |
| return punct; |
| |
| /* TS 44.060 9.3.2.1.1 */ |
| if ((cs == MCS9) && |
| (cs_current == MCS6)) { |
| if ((punct == EGPRS_PS_1) || (punct == EGPRS_PS_3)) |
| return EGPRS_PS_1; |
| else if (punct == EGPRS_PS_2) |
| return EGPRS_PS_2; |
| } else if ((cs == MCS6) && |
| (cs_current == MCS9)) { |
| if (punct == EGPRS_PS_1) |
| return EGPRS_PS_3; |
| else if (punct == EGPRS_PS_2) |
| return EGPRS_PS_2; |
| } else if ((cs == MCS7) && |
| (cs_current == MCS5)) |
| return EGPRS_PS_1; |
| else if ((cs == MCS5) && |
| (cs_current == MCS7)) |
| return EGPRS_PS_2; |
| else if (cs != cs_current) |
| return EGPRS_PS_1; |
| /* TS 44.060 9.3.2.1.1 ends here */ |
| /* |
| * Below else will handle fresh transmission, retransmission with no |
| * MCS change case |
| */ |
| else |
| return punct; |
| return EGPRS_PS_INVALID; |
| } |
| |
| /* |
| * This function calculates puncturing scheme for retransmission of a RLC |
| * block with same MCS. The computed value shall be used for next transmission |
| * of the same RLC block |
| * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 |
| */ |
| void gprs_update_punct_scheme(enum egprs_puncturing_values *punct, |
| const enum CodingScheme &cs) |
| { |
| switch (cs) { |
| case MCS1 : |
| case MCS2 : |
| case MCS5 : |
| case MCS6 : |
| *punct = ((enum egprs_puncturing_values)((*punct + 1) % |
| EGPRS_MAX_PS_NUM_2)); |
| break; |
| case MCS3 : |
| case MCS4 : |
| case MCS7 : |
| case MCS8 : |
| case MCS9 : |
| *punct = ((enum egprs_puncturing_values)((*punct + 1) % |
| EGPRS_MAX_PS_NUM_3)); |
| break; |
| default: |
| break; |
| } |
| } |