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author | David Vrabel <david.vrabel@csr.com> | 2008-09-17 19:34:09 +0400 |
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committer | David Vrabel <dv02@dv02pc01.europe.root.pri> | 2008-09-17 19:54:24 +0400 |
commit | 8cc13a09474bb30d15dbf449767bb6d0198a8bf8 (patch) | |
tree | 2423388e0a7e9bca0c6e6f7edd5f492887d38160 /drivers/uwb/drp.c | |
parent | 22d203ecef9b0cc1fa8d8f64c935b451ca7d1022 (diff) | |
download | linux-8cc13a09474bb30d15dbf449767bb6d0198a8bf8.tar.xz |
uwb: add the UWB stack (reservation manager)
DRP and reservation management.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Diffstat (limited to 'drivers/uwb/drp.c')
-rw-r--r-- | drivers/uwb/drp.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/drivers/uwb/drp.c b/drivers/uwb/drp.c new file mode 100644 index 000000000000..c0b1e5e2bd08 --- /dev/null +++ b/drivers/uwb/drp.c @@ -0,0 +1,461 @@ +/* + * Ultra Wide Band + * Dynamic Reservation Protocol handling + * + * Copyright (C) 2005-2006 Intel Corporation + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> + * Copyright (C) 2008 Cambridge Silicon Radio Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * 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 <http://www.gnu.org/licenses/>. + */ +#include <linux/kthread.h> +#include <linux/freezer.h> +#include <linux/delay.h> +#include "uwb-internal.h" + +/** + * Construct and send the SET DRP IE + * + * @rc: UWB Host controller + * @returns: >= 0 number of bytes still available in the beacon + * < 0 errno code on error. + * + * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the + * device to include in its beacon at the same time. We thus have to + * traverse all reservations and include the DRP IEs of all PENDING + * and NEGOTIATED reservations in a SET DRP command for transmission. + * + * A DRP Availability IE is appended. + * + * rc->uwb_dev.mutex is held + * + * FIXME We currently ignore the returned value indicating the remaining space + * in beacon. This could be used to deny reservation requests earlier if + * determined that they would cause the beacon space to be exceeded. + */ +static +int uwb_rc_gen_send_drp_ie(struct uwb_rc *rc) +{ + int result; + struct device *dev = &rc->uwb_dev.dev; + struct uwb_rc_cmd_set_drp_ie *cmd; + struct uwb_rc_evt_set_drp_ie reply; + struct uwb_rsv *rsv; + int num_bytes = 0; + u8 *IEDataptr; + + result = -ENOMEM; + /* First traverse all reservations to determine memory needed. */ + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (rsv->drp_ie != NULL) + num_bytes += rsv->drp_ie->hdr.length + 2; + } + num_bytes += sizeof(rc->drp_avail.ie); + cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL); + if (cmd == NULL) + goto error; + cmd->rccb.bCommandType = UWB_RC_CET_GENERAL; + cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE); + cmd->wIELength = num_bytes; + IEDataptr = (u8 *)&cmd->IEData[0]; + + /* Next traverse all reservations to place IEs in allocated memory. */ + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (rsv->drp_ie != NULL) { + memcpy(IEDataptr, rsv->drp_ie, + rsv->drp_ie->hdr.length + 2); + IEDataptr += rsv->drp_ie->hdr.length + 2; + } + } + memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie)); + + reply.rceb.bEventType = UWB_RC_CET_GENERAL; + reply.rceb.wEvent = UWB_RC_CMD_SET_DRP_IE; + result = uwb_rc_cmd(rc, "SET-DRP-IE", &cmd->rccb, + sizeof(*cmd) + num_bytes, &reply.rceb, + sizeof(reply)); + if (result < 0) + goto error_cmd; + result = le16_to_cpu(reply.wRemainingSpace); + if (reply.bResultCode != UWB_RC_RES_SUCCESS) { + dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: command execution " + "failed: %s (%d). RemainingSpace in beacon " + "= %d\n", uwb_rc_strerror(reply.bResultCode), + reply.bResultCode, result); + result = -EIO; + } else { + dev_dbg(dev, "SET-DRP-IE sent. RemainingSpace in beacon " + "= %d.\n", result); + result = 0; + } +error_cmd: + kfree(cmd); +error: + return result; + +} +/** + * Send all DRP IEs associated with this host + * + * @returns: >= 0 number of bytes still available in the beacon + * < 0 errno code on error. + * + * As per the protocol we obtain the host controller device lock to access + * bandwidth structures. + */ +int uwb_rc_send_all_drp_ie(struct uwb_rc *rc) +{ + int result; + + mutex_lock(&rc->uwb_dev.mutex); + result = uwb_rc_gen_send_drp_ie(rc); + mutex_unlock(&rc->uwb_dev.mutex); + return result; +} + +void uwb_drp_handle_timeout(struct uwb_rsv *rsv) +{ + struct device *dev = &rsv->rc->uwb_dev.dev; + + dev_dbg(dev, "reservation timeout in state %s (%d)\n", + uwb_rsv_state_str(rsv->state), rsv->state); + + switch (rsv->state) { + case UWB_RSV_STATE_O_INITIATED: + if (rsv->is_multicast) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); + return; + } + break; + case UWB_RSV_STATE_O_ESTABLISHED: + if (rsv->is_multicast) + return; + break; + default: + break; + } + uwb_rsv_remove(rsv); +} + +/* + * Based on the DRP IE, transition a target reservation to a new + * state. + */ +static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv, + struct uwb_ie_drp *drp_ie) +{ + struct device *dev = &rc->uwb_dev.dev; + int status; + enum uwb_drp_reason reason_code; + + status = uwb_ie_drp_status(drp_ie); + reason_code = uwb_ie_drp_reason_code(drp_ie); + + if (status) { + switch (reason_code) { + case UWB_DRP_REASON_ACCEPTED: + uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED); + break; + case UWB_DRP_REASON_MODIFIED: + dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", + reason_code, status); + break; + default: + dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", + reason_code, status); + } + } else { + switch (reason_code) { + case UWB_DRP_REASON_ACCEPTED: + /* New reservations are handled in uwb_rsv_find(). */ + break; + case UWB_DRP_REASON_DENIED: + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + break; + case UWB_DRP_REASON_CONFLICT: + case UWB_DRP_REASON_MODIFIED: + dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", + reason_code, status); + break; + default: + dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", + reason_code, status); + } + } +} + +/* + * Based on the DRP IE, transition an owner reservation to a new + * state. + */ +static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv, + struct uwb_ie_drp *drp_ie) +{ + struct device *dev = &rc->uwb_dev.dev; + int status; + enum uwb_drp_reason reason_code; + + status = uwb_ie_drp_status(drp_ie); + reason_code = uwb_ie_drp_reason_code(drp_ie); + + if (status) { + switch (reason_code) { + case UWB_DRP_REASON_ACCEPTED: + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); + break; + case UWB_DRP_REASON_MODIFIED: + dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", + reason_code, status); + break; + default: + dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", + reason_code, status); + } + } else { + switch (reason_code) { + case UWB_DRP_REASON_PENDING: + uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING); + break; + case UWB_DRP_REASON_DENIED: + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + break; + case UWB_DRP_REASON_CONFLICT: + case UWB_DRP_REASON_MODIFIED: + dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", + reason_code, status); + break; + default: + dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", + reason_code, status); + } + } +} + +/* + * Process a received DRP IE, it's either for a reservation owned by + * the RC or targeted at it (or it's for a WUSB cluster reservation). + */ +static void uwb_drp_process(struct uwb_rc *rc, struct uwb_dev *src, + struct uwb_ie_drp *drp_ie) +{ + struct uwb_rsv *rsv; + + rsv = uwb_rsv_find(rc, src, drp_ie); + if (!rsv) { + /* + * No reservation? It's either for a recently + * terminated reservation; or the DRP IE couldn't be + * processed (e.g., an invalid IE or out of memory). + */ + return; + } + + /* + * Do nothing with DRP IEs for reservations that have been + * terminated. + */ + if (rsv->state == UWB_RSV_STATE_NONE) { + uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); + return; + } + + if (uwb_ie_drp_owner(drp_ie)) + uwb_drp_process_target(rc, rsv, drp_ie); + else + uwb_drp_process_owner(rc, rsv, drp_ie); +} + + +/* + * Process all the DRP IEs (both DRP IEs and the DRP Availability IE) + * from a device. + */ +static +void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt, + size_t ielen, struct uwb_dev *src_dev) +{ + struct device *dev = &rc->uwb_dev.dev; + struct uwb_ie_hdr *ie_hdr; + void *ptr; + + ptr = drp_evt->ie_data; + for (;;) { + ie_hdr = uwb_ie_next(&ptr, &ielen); + if (!ie_hdr) + break; + + switch (ie_hdr->element_id) { + case UWB_IE_DRP_AVAILABILITY: + /* FIXME: does something need to be done with this? */ + break; + case UWB_IE_DRP: + uwb_drp_process(rc, src_dev, (struct uwb_ie_drp *)ie_hdr); + break; + default: + dev_warn(dev, "unexpected IE in DRP notification\n"); + break; + } + } + + if (ielen > 0) + dev_warn(dev, "%d octets remaining in DRP notification\n", + (int)ielen); +} + + +/* + * Go through all the DRP IEs and find the ones that conflict with our + * reservations. + * + * FIXME: must resolve the conflict according the the rules in + * [ECMA-368]. + */ +static +void uwb_drp_process_conflict_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt, + size_t ielen, struct uwb_dev *src_dev) +{ + struct device *dev = &rc->uwb_dev.dev; + struct uwb_ie_hdr *ie_hdr; + struct uwb_ie_drp *drp_ie; + void *ptr; + + ptr = drp_evt->ie_data; + for (;;) { + ie_hdr = uwb_ie_next(&ptr, &ielen); + if (!ie_hdr) + break; + + drp_ie = container_of(ie_hdr, struct uwb_ie_drp, hdr); + + /* FIXME: check if this DRP IE conflicts. */ + } + + if (ielen > 0) + dev_warn(dev, "%d octets remaining in DRP notification\n", + (int)ielen); +} + + +/* + * Terminate all reservations owned by, or targeted at, 'uwb_dev'. + */ +static void uwb_drp_terminate_all(struct uwb_rc *rc, struct uwb_dev *uwb_dev) +{ + struct uwb_rsv *rsv; + + list_for_each_entry(rsv, &rc->reservations, rc_node) { + if (rsv->owner == uwb_dev + || (rsv->target.type == UWB_RSV_TARGET_DEV && rsv->target.dev == uwb_dev)) + uwb_rsv_remove(rsv); + } +} + + +/** + * uwbd_evt_handle_rc_drp - handle a DRP_IE event + * @evt: the DRP_IE event from the radio controller + * + * This processes DRP notifications from the radio controller, either + * initiating a new reservation or transitioning an existing + * reservation into a different state. + * + * DRP notifications can occur for three different reasons: + * + * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as + * the target or source have been recieved. + * + * These DRP IEs could be new or for an existing reservation. + * + * If the DRP IE for an existing reservation ceases to be to + * recieved for at least mMaxLostBeacons, the reservation should be + * considered to be terminated. Note that the TERMINATE reason (see + * below) may not always be signalled (e.g., the remote device has + * two or more reservations established with the RC). + * + * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon + * group conflict with the RC's reservations. + * + * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received + * from a device (i.e., it's terminated all reservations). + * + * Only the software state of the reservations is changed; the setting + * of the radio controller's DRP IEs is done after all the events in + * an event buffer are processed. This saves waiting multiple times + * for the SET_DRP_IE command to complete. + */ +int uwbd_evt_handle_rc_drp(struct uwb_event *evt) +{ + struct device *dev = &evt->rc->uwb_dev.dev; + struct uwb_rc *rc = evt->rc; + struct uwb_rc_evt_drp *drp_evt; + size_t ielength, bytes_left; + struct uwb_dev_addr src_addr; + struct uwb_dev *src_dev; + int reason; + + /* Is there enough data to decode the event (and any IEs in + its payload)? */ + if (evt->notif.size < sizeof(*drp_evt)) { + dev_err(dev, "DRP event: Not enough data to decode event " + "[%zu bytes left, %zu needed]\n", + evt->notif.size, sizeof(*drp_evt)); + return 0; + } + bytes_left = evt->notif.size - sizeof(*drp_evt); + drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb); + ielength = le16_to_cpu(drp_evt->ie_length); + if (bytes_left != ielength) { + dev_err(dev, "DRP event: Not enough data in payload [%zu" + "bytes left, %zu declared in the event]\n", + bytes_left, ielength); + return 0; + } + + memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr)); + src_dev = uwb_dev_get_by_devaddr(rc, &src_addr); + if (!src_dev) { + /* + * A DRP notification from an unrecognized device. + * + * This is probably from a WUSB device that doesn't + * have an EUI-48 and therefore doesn't show up in the + * UWB device database. It's safe to simply ignore + * these. + */ + return 0; + } + + mutex_lock(&rc->rsvs_mutex); + + reason = uwb_rc_evt_drp_reason(drp_evt); + + switch (reason) { + case UWB_DRP_NOTIF_DRP_IE_RCVD: + uwb_drp_process_all(rc, drp_evt, ielength, src_dev); + break; + case UWB_DRP_NOTIF_CONFLICT: + uwb_drp_process_conflict_all(rc, drp_evt, ielength, src_dev); + break; + case UWB_DRP_NOTIF_TERMINATE: + uwb_drp_terminate_all(rc, src_dev); + break; + default: + dev_warn(dev, "ignored DRP event with reason code: %d\n", reason); + break; + } + + mutex_unlock(&rc->rsvs_mutex); + + uwb_dev_put(src_dev); + return 0; +} |