/********************************************************************* * * Filename: qos.c * Version: 1.0 * Description: IrLAP QoS parameter negotiation * Status: Stable * Author: Dag Brattli * Created at: Tue Sep 9 00:00:26 1997 * Modified at: Sun Jan 30 14:29:16 2000 * Modified by: Dag Brattli * * Copyright (c) 1998-2000 Dag Brattli , * All Rights Reserved. * Copyright (c) 2000-2001 Jean Tourrilhes * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * ********************************************************************/ #include #include #include #include #include #include #include /* * Maximum values of the baud rate we negotiate with the other end. * Most often, you don't have to change that, because Linux-IrDA will * use the maximum offered by the link layer, which usually works fine. * In some very rare cases, you may want to limit it to lower speeds... */ int sysctl_max_baud_rate = 16000000; /* * Maximum value of the lap disconnect timer we negotiate with the other end. * Most often, the value below represent the best compromise, but some user * may want to keep the LAP alive longer or shorter in case of link failure. * Remember that the threshold time (early warning) is fixed to 3s... */ int sysctl_max_noreply_time = 12; /* * Minimum turn time to be applied before transmitting to the peer. * Nonzero values (usec) are used as lower limit to the per-connection * mtt value which was announced by the other end during negotiation. * Might be helpful if the peer device provides too short mtt. * Default is 10us which means using the unmodified value given by the * peer except if it's 0 (0 is likely a bug in the other stack). */ unsigned int sysctl_min_tx_turn_time = 10; /* * Maximum data size to be used in transmission in payload of LAP frame. * There is a bit of confusion in the IrDA spec : * The LAP spec defines the payload of a LAP frame (I field) to be * 2048 bytes max (IrLAP 1.1, chapt 6.6.5, p40). * On the other hand, the PHY mention frames of 2048 bytes max (IrPHY * 1.2, chapt 5.3.2.1, p41). But, this number includes the LAP header * (2 bytes), and CRC (32 bits at 4 Mb/s). So, for the I field (LAP * payload), that's only 2042 bytes. Oups ! * My nsc-ircc hardware has troubles receiving 2048 bytes frames at 4 Mb/s, * so adjust to 2042... I don't know if this bug applies only for 2048 * bytes frames or all negotiated frame sizes, but you can use the sysctl * to play with this value anyway. * Jean II */ unsigned int sysctl_max_tx_data_size = 2042; /* * Maximum transmit window, i.e. number of LAP frames between turn-around. * This allow to override what the peer told us. Some peers are buggy and * don't always support what they tell us. * Jean II */ unsigned int sysctl_max_tx_window = 7; static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get); static int irlap_param_link_disconnect(void *instance, irda_param_t *parm, int get); static int irlap_param_max_turn_time(void *instance, irda_param_t *param, int get); static int irlap_param_data_size(void *instance, irda_param_t *param, int get); static int irlap_param_window_size(void *instance, irda_param_t *param, int get); static int irlap_param_additional_bofs(void *instance, irda_param_t *parm, int get); static int irlap_param_min_turn_time(void *instance, irda_param_t *param, int get); #ifndef CONFIG_IRDA_DYNAMIC_WINDOW static __u32 irlap_requested_line_capacity(struct qos_info *qos); #endif static __u32 min_turn_times[] = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */ static __u32 baud_rates[] = { 2400, 9600, 19200, 38400, 57600, 115200, 576000, 1152000, 4000000, 16000000 }; /* bps */ static __u32 data_sizes[] = { 64, 128, 256, 512, 1024, 2048 }; /* bytes */ static __u32 add_bofs[] = { 48, 24, 12, 5, 3, 2, 1, 0 }; /* bytes */ static __u32 max_turn_times[] = { 500, 250, 100, 50 }; /* ms */ static __u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 }; /* secs */ static __u32 max_line_capacities[10][4] = { /* 500 ms 250 ms 100 ms 50 ms (max turn time) */ { 100, 0, 0, 0 }, /* 2400 bps */ { 400, 0, 0, 0 }, /* 9600 bps */ { 800, 0, 0, 0 }, /* 19200 bps */ { 1600, 0, 0, 0 }, /* 38400 bps */ { 2360, 0, 0, 0 }, /* 57600 bps */ { 4800, 2400, 960, 480 }, /* 115200 bps */ { 28800, 11520, 5760, 2880 }, /* 576000 bps */ { 57600, 28800, 11520, 5760 }, /* 1152000 bps */ { 200000, 100000, 40000, 20000 }, /* 4000000 bps */ { 800000, 400000, 160000, 80000 }, /* 16000000 bps */ }; static pi_minor_info_t pi_minor_call_table_type_0[] = { { NULL, 0 }, /* 01 */{ irlap_param_baud_rate, PV_INTEGER | PV_LITTLE_ENDIAN }, { NULL, 0 }, { NULL, 0 }, { NULL, 0 }, { NULL, 0 }, { NULL, 0 }, { NULL, 0 }, /* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS } }; static pi_minor_info_t pi_minor_call_table_type_1[] = { { NULL, 0 }, { NULL, 0 }, /* 82 */{ irlap_param_max_turn_time, PV_INT_8_BITS }, /* 83 */{ irlap_param_data_size, PV_INT_8_BITS }, /* 84 */{ irlap_param_window_size, PV_INT_8_BITS }, /* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS }, /* 86 */{ irlap_param_min_turn_time, PV_INT_8_BITS }, }; static pi_major_info_t pi_major_call_table[] = { { pi_minor_call_table_type_0, 9 }, { pi_minor_call_table_type_1, 7 }, }; static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 }; /* ---------------------- LOCAL SUBROUTINES ---------------------- */ /* Note : we start with a bunch of local subroutines. * As the compiler is "one pass", this is the only way to get them to * inline properly... * Jean II */ /* * Function value_index (value, array, size) * * Returns the index to the value in the specified array */ static inline int value_index(__u32 value, __u32 *array, int size) { int i; for (i=0; i < size; i++) if (array[i] == value) break; return i; } /* * Function index_value (index, array) * * Returns value to index in array, easy! * */ static inline __u32 index_value(int index, __u32 *array) { return array[index]; } /* * Function msb_index (word) * * Returns index to most significant bit (MSB) in word * */ static int msb_index (__u16 word) { __u16 msb = 0x8000; int index = 15; /* Current MSB */ /* Check for buggy peers. * Note : there is a small probability that it could be us, but I * would expect driver authors to catch that pretty early and be * able to check precisely what's going on. If a end user sees this, * it's very likely the peer. - Jean II */ if (word == 0) { net_warn_ratelimited("%s(), Detected buggy peer, adjust null PV to 0x1!\n", __func__); /* The only safe choice (we don't know the array size) */ word = 0x1; } while (msb) { if (word & msb) break; /* Found it! */ msb >>=1; index--; } return index; } /* * Function value_lower_bits (value, array) * * Returns a bit field marking all possibility lower than value. */ static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field) { int i; __u16 mask = 0x1; __u16 result = 0x0; for (i=0; i < size; i++) { /* Add the current value to the bit field, shift mask */ result |= mask; mask <<= 1; /* Finished ? */ if (array[i] >= value) break; } /* Send back a valid index */ if(i >= size) i = size - 1; /* Last item */ *field = result; return i; } /* * Function value_highest_bit (value, array) * * Returns a bit field marking the highest possibility lower than value. */ static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field) { int i; __u16 mask = 0x1; __u16 result = 0x0; for (i=0; i < size; i++) { /* Finished ? */ if (array[i] <= value) break; /* Shift mask */ mask <<= 1; } /* Set the current value to the bit field */ result |= mask; /* Send back a valid index */ if(i >= size) i = size - 1; /* Last item */ *field = result; return i; } /* -------------------------- MAIN CALLS -------------------------- */ /* * Function irda_qos_compute_intersection (qos, new) * * Compute the intersection of the old QoS capabilities with new ones * */ void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new) { IRDA_ASSERT(qos != NULL, return;); IRDA_ASSERT(new != NULL, return;); /* Apply */ qos->baud_rate.bits &= new->baud_rate.bits; qos->window_size.bits &= new->window_size.bits; qos->min_turn_time.bits &= new->min_turn_time.bits; qos->max_turn_time.bits &= new->max_turn_time.bits; qos->data_size.bits &= new->data_size.bits; qos->link_disc_time.bits &= new->link_disc_time.bits; qos->additional_bofs.bits &= new->additional_bofs.bits; irda_qos_bits_to_value(qos); } /* * Function irda_init_max_qos_capabilies (qos) * * The purpose of this function is for layers and drivers to be able to * set the maximum QoS possible and then "and in" their own limitations * */ void irda_init_max_qos_capabilies(struct qos_info *qos) { int i; /* * These are the maximum supported values as specified on pages * 39-43 in IrLAP */ /* Use sysctl to set some configurable values... */ /* Set configured max speed */ i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10, &qos->baud_rate.bits); sysctl_max_baud_rate = index_value(i, baud_rates); /* Set configured max disc time */ i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8, &qos->link_disc_time.bits); sysctl_max_noreply_time = index_value(i, link_disc_times); /* LSB is first byte, MSB is second byte */ qos->baud_rate.bits &= 0x03ff; qos->window_size.bits = 0x7f; qos->min_turn_time.bits = 0xff; qos->max_turn_time.bits = 0x0f; qos->data_size.bits = 0x3f; qos->link_disc_time.bits &= 0xff; qos->additional_bofs.bits = 0xff; } EXPORT_SYMBOL(irda_init_max_qos_capabilies); /* * Function irlap_adjust_qos_settings (qos) * * Adjust QoS settings in case some values are not possible to use because * of other settings */ static void irlap_adjust_qos_settings(struct qos_info *qos) { __u32 line_capacity; int index; /* * Make sure the mintt is sensible. * Main culprit : Ericsson T39. - Jean II */ if (sysctl_min_tx_turn_time > qos->min_turn_time.value) { int i; net_warn_ratelimited("%s(), Detected buggy peer, adjust mtt to %dus!\n", __func__, sysctl_min_tx_turn_time); /* We don't really need bits, but easier this way */ i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times, 8, &qos->min_turn_time.bits); sysctl_min_tx_turn_time = index_value(i, min_turn_times); qos->min_turn_time.value = sysctl_min_tx_turn_time; } /* * Not allowed to use a max turn time less than 500 ms if the baudrate * is less than 115200 */ if ((qos->baud_rate.value < 115200) && (qos->max_turn_time.value < 500)) { pr_debug("%s(), adjusting max turn time from %d to 500 ms\n", __func__, qos->max_turn_time.value); qos->max_turn_time.value = 500; } /* * The data size must be adjusted according to the baud rate and max * turn time */ index = value_index(qos->data_size.value, data_sizes, 6); line_capacity = irlap_max_line_capacity(qos->baud_rate.value, qos->max_turn_time.value); #ifdef CONFIG_IRDA_DYNAMIC_WINDOW while ((qos->data_size.value > line_capacity) && (index > 0)) { qos->data_size.value = data_sizes[index--]; pr_debug("%s(), reducing data size to %d\n", __func__, qos->data_size.value); } #else /* Use method described in section 6.6.11 of IrLAP */ while (irlap_requested_line_capacity(qos) > line_capacity) { IRDA_ASSERT(index != 0, return;); /* Must be able to send at least one frame */ if (qos->window_size.value > 1) { qos->window_size.value--; pr_debug("%s(), reducing window size to %d\n", __func__, qos->window_size.value); } else if (index > 1) { qos->data_size.value = data_sizes[index--]; pr_debug("%s(), reducing data size to %d\n", __func__, qos->data_size.value); } else { net_warn_ratelimited("%s(), nothing more we can do!\n", __func__); } } #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ /* * Fix tx data size according to user limits - Jean II */ if (qos->data_size.value > sysctl_max_tx_data_size) /* Allow non discrete adjustement to avoid losing capacity */ qos->data_size.value = sysctl_max_tx_data_size; /* * Override Tx window if user request it. - Jean II */ if (qos->window_size.value > sysctl_max_tx_window) qos->window_size.value = sysctl_max_tx_window; } /* * Function irlap_negotiate (qos_device, qos_session, skb) * * Negotiate QoS values, not really that much negotiation :-) * We just set the QoS capabilities for the peer station * */ int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb) { int ret; ret = irda_param_extract_all(self, skb->data, skb->len, &irlap_param_info); /* Convert the negotiated bits to values */ irda_qos_bits_to_value(&self->qos_tx); irda_qos_bits_to_value(&self->qos_rx); irlap_adjust_qos_settings(&self->qos_tx); pr_debug("Setting BAUD_RATE to %d bps.\n", self->qos_tx.baud_rate.value); pr_debug("Setting DATA_SIZE to %d bytes\n", self->qos_tx.data_size.value); pr_debug("Setting WINDOW_SIZE to %d\n", self->qos_tx.window_size.value); pr_debug("Setting XBOFS to %d\n", self->qos_tx.additional_bofs.value); pr_debug("Setting MAX_TURN_TIME to %d ms.\n", self->qos_tx.max_turn_time.value); pr_debug("Setting MIN_TURN_TIME to %d usecs.\n", self->qos_tx.min_turn_time.value); pr_debug("Setting LINK_DISC to %d secs.\n", self->qos_tx.link_disc_time.value); return ret; } /* * Function irlap_insert_negotiation_params (qos, fp) * * Insert QoS negotiaion pararameters into frame * */ int irlap_insert_qos_negotiation_params(struct irlap_cb *self, struct sk_buff *skb) { int ret; /* Insert data rate */ ret = irda_param_insert(self, PI_BAUD_RATE, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert max turnaround time */ ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert data size */ ret = irda_param_insert(self, PI_DATA_SIZE, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert window size */ ret = irda_param_insert(self, PI_WINDOW_SIZE, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert additional BOFs */ ret = irda_param_insert(self, PI_ADD_BOFS, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert minimum turnaround time */ ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); /* Insert link disconnect/threshold time */ ret = irda_param_insert(self, PI_LINK_DISC, skb_tail_pointer(skb), skb_tailroom(skb), &irlap_param_info); if (ret < 0) return ret; skb_put(skb, ret); return 0; } /* * Function irlap_param_baud_rate (instance, param, get) * * Negotiate data-rate * */ static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get) { __u16 final; struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) { param->pv.i = self->qos_rx.baud_rate.bits; pr_debug("%s(), baud rate = 0x%02x\n", __func__, param->pv.i); } else { /* * Stations must agree on baud rate, so calculate * intersection */ pr_debug("Requested BAUD_RATE: 0x%04x\n", (__u16)param->pv.i); final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits; pr_debug("Final BAUD_RATE: 0x%04x\n", final); self->qos_tx.baud_rate.bits = final; self->qos_rx.baud_rate.bits = final; } return 0; } /* * Function irlap_param_link_disconnect (instance, param, get) * * Negotiate link disconnect/threshold time. * */ static int irlap_param_link_disconnect(void *instance, irda_param_t *param, int get) { __u16 final; struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.link_disc_time.bits; else { /* * Stations must agree on link disconnect/threshold * time. */ pr_debug("LINK_DISC: %02x\n", (__u8)param->pv.i); final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits; pr_debug("Final LINK_DISC: %02x\n", final); self->qos_tx.link_disc_time.bits = final; self->qos_rx.link_disc_time.bits = final; } return 0; } /* * Function irlap_param_max_turn_time (instance, param, get) * * Negotiate the maximum turnaround time. This is a type 1 parameter and * will be negotiated independently for each station * */ static int irlap_param_max_turn_time(void *instance, irda_param_t *param, int get) { struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.max_turn_time.bits; else self->qos_tx.max_turn_time.bits = (__u8) param->pv.i; return 0; } /* * Function irlap_param_data_size (instance, param, get) * * Negotiate the data size. This is a type 1 parameter and * will be negotiated independently for each station * */ static int irlap_param_data_size(void *instance, irda_param_t *param, int get) { struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.data_size.bits; else self->qos_tx.data_size.bits = (__u8) param->pv.i; return 0; } /* * Function irlap_param_window_size (instance, param, get) * * Negotiate the window size. This is a type 1 parameter and * will be negotiated independently for each station * */ static int irlap_param_window_size(void *instance, irda_param_t *param, int get) { struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.window_size.bits; else self->qos_tx.window_size.bits = (__u8) param->pv.i; return 0; } /* * Function irlap_param_additional_bofs (instance, param, get) * * Negotiate additional BOF characters. This is a type 1 parameter and * will be negotiated independently for each station. */ static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get) { struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.additional_bofs.bits; else self->qos_tx.additional_bofs.bits = (__u8) param->pv.i; return 0; } /* * Function irlap_param_min_turn_time (instance, param, get) * * Negotiate the minimum turn around time. This is a type 1 parameter and * will be negotiated independently for each station */ static int irlap_param_min_turn_time(void *instance, irda_param_t *param, int get) { struct irlap_cb *self = (struct irlap_cb *) instance; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); if (get) param->pv.i = self->qos_rx.min_turn_time.bits; else self->qos_tx.min_turn_time.bits = (__u8) param->pv.i; return 0; } /* * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time) * * Calculate the maximum line capacity * */ __u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time) { __u32 line_capacity; int i,j; pr_debug("%s(), speed=%d, max_turn_time=%d\n", __func__, speed, max_turn_time); i = value_index(speed, baud_rates, 10); j = value_index(max_turn_time, max_turn_times, 4); IRDA_ASSERT(((i >=0) && (i <10)), return 0;); IRDA_ASSERT(((j >=0) && (j <4)), return 0;); line_capacity = max_line_capacities[i][j]; pr_debug("%s(), line capacity=%d bytes\n", __func__, line_capacity); return line_capacity; } #ifndef CONFIG_IRDA_DYNAMIC_WINDOW static __u32 irlap_requested_line_capacity(struct qos_info *qos) { __u32 line_capacity; line_capacity = qos->window_size.value * (qos->data_size.value + 6 + qos->additional_bofs.value) + irlap_min_turn_time_in_bytes(qos->baud_rate.value, qos->min_turn_time.value); pr_debug("%s(), requested line capacity=%d\n", __func__, line_capacity); return line_capacity; } #endif void irda_qos_bits_to_value(struct qos_info *qos) { int index; IRDA_ASSERT(qos != NULL, return;); index = msb_index(qos->baud_rate.bits); qos->baud_rate.value = baud_rates[index]; index = msb_index(qos->data_size.bits); qos->data_size.value = data_sizes[index]; index = msb_index(qos->window_size.bits); qos->window_size.value = index+1; index = msb_index(qos->min_turn_time.bits); qos->min_turn_time.value = min_turn_times[index]; index = msb_index(qos->max_turn_time.bits); qos->max_turn_time.value = max_turn_times[index]; index = msb_index(qos->link_disc_time.bits); qos->link_disc_time.value = link_disc_times[index]; index = msb_index(qos->additional_bofs.bits); qos->additional_bofs.value = add_bofs[index]; } EXPORT_SYMBOL(irda_qos_bits_to_value);