/*
* 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;
}
