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Diffstat (limited to 'drivers/staging/uwb/uwb.h')
| -rw-r--r-- | drivers/staging/uwb/uwb.h | 817 |
1 files changed, 0 insertions, 817 deletions
diff --git a/drivers/staging/uwb/uwb.h b/drivers/staging/uwb/uwb.h deleted file mode 100644 index 6a59706ba3a0..000000000000 --- a/drivers/staging/uwb/uwb.h +++ /dev/null @@ -1,817 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Ultra Wide Band - * UWB API - * - * Copyright (C) 2005-2006 Intel Corporation - * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> - * - * FIXME: doc: overview of the API, different parts and pointers - */ - -#ifndef __LINUX__UWB_H__ -#define __LINUX__UWB_H__ - -#include <linux/limits.h> -#include <linux/device.h> -#include <linux/mutex.h> -#include <linux/timer.h> -#include <linux/wait.h> -#include <linux/workqueue.h> -#include <asm/page.h> -#include "include/spec.h" - -struct uwb_dev; -struct uwb_beca_e; -struct uwb_rc; -struct uwb_rsv; -struct uwb_dbg; - -/** - * struct uwb_dev - a UWB Device - * @rc: UWB Radio Controller that discovered the device (kind of its - * parent). - * @bce: a beacon cache entry for this device; or NULL if the device - * is a local radio controller. - * @mac_addr: the EUI-48 address of this device. - * @dev_addr: the current DevAddr used by this device. - * @beacon_slot: the slot number the beacon is using. - * @streams: bitmap of streams allocated to reservations targeted at - * this device. For an RC, this is the streams allocated for - * reservations targeted at DevAddrs. - * - * A UWB device may either by a neighbor or part of a local radio - * controller. - */ -struct uwb_dev { - struct mutex mutex; - struct list_head list_node; - struct device dev; - struct uwb_rc *rc; /* radio controller */ - struct uwb_beca_e *bce; /* Beacon Cache Entry */ - - struct uwb_mac_addr mac_addr; - struct uwb_dev_addr dev_addr; - int beacon_slot; - DECLARE_BITMAP(streams, UWB_NUM_STREAMS); - DECLARE_BITMAP(last_availability_bm, UWB_NUM_MAS); -}; -#define to_uwb_dev(d) container_of(d, struct uwb_dev, dev) - -/** - * UWB HWA/WHCI Radio Control {Command|Event} Block context IDs - * - * RC[CE]Bs have a 'context ID' field that matches the command with - * the event received to confirm it. - * - * Maximum number of context IDs - */ -enum { UWB_RC_CTX_MAX = 256 }; - - -/** Notification chain head for UWB generated events to listeners */ -struct uwb_notifs_chain { - struct list_head list; - struct mutex mutex; -}; - -/* Beacon cache list */ -struct uwb_beca { - struct list_head list; - size_t entries; - struct mutex mutex; -}; - -/* Event handling thread. */ -struct uwbd { - int pid; - struct task_struct *task; - wait_queue_head_t wq; - struct list_head event_list; - spinlock_t event_list_lock; -}; - -/** - * struct uwb_mas_bm - a bitmap of all MAS in a superframe - * @bm: a bitmap of length #UWB_NUM_MAS - */ -struct uwb_mas_bm { - DECLARE_BITMAP(bm, UWB_NUM_MAS); - DECLARE_BITMAP(unsafe_bm, UWB_NUM_MAS); - int safe; - int unsafe; -}; - -/** - * uwb_rsv_state - UWB Reservation state. - * - * NONE - reservation is not active (no DRP IE being transmitted). - * - * Owner reservation states: - * - * INITIATED - owner has sent an initial DRP request. - * PENDING - target responded with pending Reason Code. - * MODIFIED - reservation manager is modifying an established - * reservation with a different MAS allocation. - * ESTABLISHED - the reservation has been successfully negotiated. - * - * Target reservation states: - * - * DENIED - request is denied. - * ACCEPTED - request is accepted. - * PENDING - PAL has yet to make a decision to whether to accept or - * deny. - * - * FIXME: further target states TBD. - */ -enum uwb_rsv_state { - UWB_RSV_STATE_NONE = 0, - UWB_RSV_STATE_O_INITIATED, - UWB_RSV_STATE_O_PENDING, - UWB_RSV_STATE_O_MODIFIED, - UWB_RSV_STATE_O_ESTABLISHED, - UWB_RSV_STATE_O_TO_BE_MOVED, - UWB_RSV_STATE_O_MOVE_EXPANDING, - UWB_RSV_STATE_O_MOVE_COMBINING, - UWB_RSV_STATE_O_MOVE_REDUCING, - UWB_RSV_STATE_T_ACCEPTED, - UWB_RSV_STATE_T_DENIED, - UWB_RSV_STATE_T_CONFLICT, - UWB_RSV_STATE_T_PENDING, - UWB_RSV_STATE_T_EXPANDING_ACCEPTED, - UWB_RSV_STATE_T_EXPANDING_CONFLICT, - UWB_RSV_STATE_T_EXPANDING_PENDING, - UWB_RSV_STATE_T_EXPANDING_DENIED, - UWB_RSV_STATE_T_RESIZED, - - UWB_RSV_STATE_LAST, -}; - -enum uwb_rsv_target_type { - UWB_RSV_TARGET_DEV, - UWB_RSV_TARGET_DEVADDR, -}; - -/** - * struct uwb_rsv_target - the target of a reservation. - * - * Reservations unicast and targeted at a single device - * (UWB_RSV_TARGET_DEV); or (e.g., in the case of WUSB) targeted at a - * specific (private) DevAddr (UWB_RSV_TARGET_DEVADDR). - */ -struct uwb_rsv_target { - enum uwb_rsv_target_type type; - union { - struct uwb_dev *dev; - struct uwb_dev_addr devaddr; - }; -}; - -struct uwb_rsv_move { - struct uwb_mas_bm final_mas; - struct uwb_ie_drp *companion_drp_ie; - struct uwb_mas_bm companion_mas; -}; - -/* - * Number of streams reserved for reservations targeted at DevAddrs. - */ -#define UWB_NUM_GLOBAL_STREAMS 1 - -typedef void (*uwb_rsv_cb_f)(struct uwb_rsv *rsv); - -/** - * struct uwb_rsv - a DRP reservation - * - * Data structure management: - * - * @rc: the radio controller this reservation is for - * (as target or owner) - * @rc_node: a list node for the RC - * @pal_node: a list node for the PAL - * - * Owner and target parameters: - * - * @owner: the UWB device owning this reservation - * @target: the target UWB device - * @type: reservation type - * - * Owner parameters: - * - * @max_mas: maxiumum number of MAS - * @min_mas: minimum number of MAS - * @sparsity: owner selected sparsity - * @is_multicast: true iff multicast - * - * @callback: callback function when the reservation completes - * @pal_priv: private data for the PAL making the reservation - * - * Reservation status: - * - * @status: negotiation status - * @stream: stream index allocated for this reservation - * @tiebreaker: conflict tiebreaker for this reservation - * @mas: reserved MAS - * @drp_ie: the DRP IE - * @ie_valid: true iff the DRP IE matches the reservation parameters - * - * DRP reservations are uniquely identified by the owner, target and - * stream index. However, when using a DevAddr as a target (e.g., for - * a WUSB cluster reservation) the responses may be received from - * devices with different DevAddrs. In this case, reservations are - * uniquely identified by just the stream index. A number of stream - * indexes (UWB_NUM_GLOBAL_STREAMS) are reserved for this. - */ -struct uwb_rsv { - struct uwb_rc *rc; - struct list_head rc_node; - struct list_head pal_node; - struct kref kref; - - struct uwb_dev *owner; - struct uwb_rsv_target target; - enum uwb_drp_type type; - int max_mas; - int min_mas; - int max_interval; - bool is_multicast; - - uwb_rsv_cb_f callback; - void *pal_priv; - - enum uwb_rsv_state state; - bool needs_release_companion_mas; - u8 stream; - u8 tiebreaker; - struct uwb_mas_bm mas; - struct uwb_ie_drp *drp_ie; - struct uwb_rsv_move mv; - bool ie_valid; - struct timer_list timer; - struct work_struct handle_timeout_work; -}; - -static const -struct uwb_mas_bm uwb_mas_bm_zero = { .bm = { 0 } }; - -static inline void uwb_mas_bm_copy_le(void *dst, const struct uwb_mas_bm *mas) -{ - bitmap_copy_le(dst, mas->bm, UWB_NUM_MAS); -} - -/** - * struct uwb_drp_avail - a radio controller's view of MAS usage - * @global: MAS unused by neighbors (excluding reservations targeted - * or owned by the local radio controller) or the beaon period - * @local: MAS unused by local established reservations - * @pending: MAS unused by local pending reservations - * @ie: DRP Availability IE to be included in the beacon - * @ie_valid: true iff @ie is valid and does not need to regenerated from - * @global and @local - * - * Each radio controller maintains a view of MAS usage or - * availability. MAS available for a new reservation are determined - * from the intersection of @global, @local, and @pending. - * - * The radio controller must transmit a DRP Availability IE that's the - * intersection of @global and @local. - * - * A set bit indicates the MAS is unused and available. - * - * rc->rsvs_mutex should be held before accessing this data structure. - * - * [ECMA-368] section 17.4.3. - */ -struct uwb_drp_avail { - DECLARE_BITMAP(global, UWB_NUM_MAS); - DECLARE_BITMAP(local, UWB_NUM_MAS); - DECLARE_BITMAP(pending, UWB_NUM_MAS); - struct uwb_ie_drp_avail ie; - bool ie_valid; -}; - -struct uwb_drp_backoff_win { - u8 window; - u8 n; - int total_expired; - struct timer_list timer; - bool can_reserve_extra_mases; -}; - -const char *uwb_rsv_state_str(enum uwb_rsv_state state); -const char *uwb_rsv_type_str(enum uwb_drp_type type); - -struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, - void *pal_priv); -void uwb_rsv_destroy(struct uwb_rsv *rsv); - -int uwb_rsv_establish(struct uwb_rsv *rsv); -int uwb_rsv_modify(struct uwb_rsv *rsv, - int max_mas, int min_mas, int sparsity); -void uwb_rsv_terminate(struct uwb_rsv *rsv); - -void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv); - -void uwb_rsv_get_usable_mas(struct uwb_rsv *orig_rsv, struct uwb_mas_bm *mas); - -/** - * Radio Control Interface instance - * - * - * Life cycle rules: those of the UWB Device. - * - * @index: an index number for this radio controller, as used in the - * device name. - * @version: version of protocol supported by this device - * @priv: Backend implementation; rw with uwb_dev.dev.sem taken. - * @cmd: Backend implementation to execute commands; rw and call - * only with uwb_dev.dev.sem taken. - * @reset: Hardware reset of radio controller and any PAL controllers. - * @filter: Backend implementation to manipulate data to and from device - * to be compliant to specification assumed by driver (WHCI - * 0.95). - * - * uwb_dev.dev.mutex is used to execute commands and update - * the corresponding structures; can't use a spinlock - * because rc->cmd() can sleep. - * @ies: This is a dynamically allocated array cacheing the - * IEs (settable by the host) that the beacon of this - * radio controller is currently sending. - * - * In reality, we store here the full command we set to - * the radio controller (which is basically a command - * prefix followed by all the IEs the beacon currently - * contains). This way we don't have to realloc and - * memcpy when setting it. - * - * We set this up in uwb_rc_ie_setup(), where we alloc - * this struct, call get_ie() [so we know which IEs are - * currently being sent, if any]. - * - * @ies_capacity:Amount of space (in bytes) allocated in @ies. The - * amount used is given by sizeof(*ies) plus ies->wIELength - * (which is a little endian quantity all the time). - * @ies_mutex: protect the IE cache - * @dbg: information for the debug interface - */ -struct uwb_rc { - struct uwb_dev uwb_dev; - int index; - u16 version; - - struct module *owner; - void *priv; - int (*start)(struct uwb_rc *rc); - void (*stop)(struct uwb_rc *rc); - int (*cmd)(struct uwb_rc *, const struct uwb_rccb *, size_t); - int (*reset)(struct uwb_rc *rc); - int (*filter_cmd)(struct uwb_rc *, struct uwb_rccb **, size_t *); - int (*filter_event)(struct uwb_rc *, struct uwb_rceb **, const size_t, - size_t *, size_t *); - - spinlock_t neh_lock; /* protects neh_* and ctx_* */ - struct list_head neh_list; /* Open NE handles */ - unsigned long ctx_bm[UWB_RC_CTX_MAX / 8 / sizeof(unsigned long)]; - u8 ctx_roll; - - int beaconing; /* Beaconing state [channel number] */ - int beaconing_forced; - int scanning; - enum uwb_scan_type scan_type:3; - unsigned ready:1; - struct uwb_notifs_chain notifs_chain; - struct uwb_beca uwb_beca; - - struct uwbd uwbd; - - struct uwb_drp_backoff_win bow; - struct uwb_drp_avail drp_avail; - struct list_head reservations; - struct list_head cnflt_alien_list; - struct uwb_mas_bm cnflt_alien_bitmap; - struct mutex rsvs_mutex; - spinlock_t rsvs_lock; - struct workqueue_struct *rsv_workq; - - struct delayed_work rsv_update_work; - struct delayed_work rsv_alien_bp_work; - int set_drp_ie_pending; - struct mutex ies_mutex; - struct uwb_rc_cmd_set_ie *ies; - size_t ies_capacity; - - struct list_head pals; - int active_pals; - - struct uwb_dbg *dbg; -}; - - -/** - * struct uwb_pal - a UWB PAL - * @name: descriptive name for this PAL (wusbhc, wlp, etc.). - * @device: a device for the PAL. Used to link the PAL and the radio - * controller in sysfs. - * @rc: the radio controller the PAL uses. - * @channel_changed: called when the channel used by the radio changes. - * A channel of -1 means the channel has been stopped. - * @new_rsv: called when a peer requests a reservation (may be NULL if - * the PAL cannot accept reservation requests). - * @channel: channel being used by the PAL; 0 if the PAL isn't using - * the radio; -1 if the PAL wishes to use the radio but - * cannot. - * @debugfs_dir: a debugfs directory which the PAL can use for its own - * debugfs files. - * - * A Protocol Adaptation Layer (PAL) is a user of the WiMedia UWB - * radio platform (e.g., WUSB, WLP or Bluetooth UWB AMP). - * - * The PALs using a radio controller must register themselves to - * permit the UWB stack to coordinate usage of the radio between the - * various PALs or to allow PALs to response to certain requests from - * peers. - * - * A struct uwb_pal should be embedded in a containing structure - * belonging to the PAL and initialized with uwb_pal_init()). Fields - * should be set appropriately by the PAL before registering the PAL - * with uwb_pal_register(). - */ -struct uwb_pal { - struct list_head node; - const char *name; - struct device *device; - struct uwb_rc *rc; - - void (*channel_changed)(struct uwb_pal *pal, int channel); - void (*new_rsv)(struct uwb_pal *pal, struct uwb_rsv *rsv); - - int channel; - struct dentry *debugfs_dir; -}; - -void uwb_pal_init(struct uwb_pal *pal); -int uwb_pal_register(struct uwb_pal *pal); -void uwb_pal_unregister(struct uwb_pal *pal); - -int uwb_radio_start(struct uwb_pal *pal); -void uwb_radio_stop(struct uwb_pal *pal); - -/* - * General public API - * - * This API can be used by UWB device drivers or by those implementing - * UWB Radio Controllers - */ -struct uwb_dev *uwb_dev_get_by_devaddr(struct uwb_rc *rc, - const struct uwb_dev_addr *devaddr); -struct uwb_dev *uwb_dev_get_by_rc(struct uwb_dev *, struct uwb_rc *); -static inline void uwb_dev_get(struct uwb_dev *uwb_dev) -{ - get_device(&uwb_dev->dev); -} -static inline void uwb_dev_put(struct uwb_dev *uwb_dev) -{ - put_device(&uwb_dev->dev); -} -struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev); - -/** - * Callback function for 'uwb_{dev,rc}_foreach()'. - * - * @dev: Linux device instance - * 'uwb_dev = container_of(dev, struct uwb_dev, dev)' - * @priv: Data passed by the caller to 'uwb_{dev,rc}_foreach()'. - * - * @returns: 0 to continue the iterations, any other val to stop - * iterating and return the value to the caller of - * _foreach(). - */ -typedef int (*uwb_dev_for_each_f)(struct device *dev, void *priv); -int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f func, void *priv); - -struct uwb_rc *uwb_rc_alloc(void); -struct uwb_rc *uwb_rc_get_by_dev(const struct uwb_dev_addr *); -struct uwb_rc *uwb_rc_get_by_grandpa(const struct device *); -void uwb_rc_put(struct uwb_rc *rc); - -typedef void (*uwb_rc_cmd_cb_f)(struct uwb_rc *rc, void *arg, - struct uwb_rceb *reply, ssize_t reply_size); - -int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name, - struct uwb_rccb *cmd, size_t cmd_size, - u8 expected_type, u16 expected_event, - uwb_rc_cmd_cb_f cb, void *arg); -ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name, - struct uwb_rccb *cmd, size_t cmd_size, - struct uwb_rceb *reply, size_t reply_size); -ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name, - struct uwb_rccb *cmd, size_t cmd_size, - u8 expected_type, u16 expected_event, - struct uwb_rceb **preply); - -size_t __uwb_addr_print(char *, size_t, const unsigned char *, int); - -int uwb_rc_dev_addr_set(struct uwb_rc *, const struct uwb_dev_addr *); -int uwb_rc_dev_addr_get(struct uwb_rc *, struct uwb_dev_addr *); -int uwb_rc_mac_addr_set(struct uwb_rc *, const struct uwb_mac_addr *); -int uwb_rc_mac_addr_get(struct uwb_rc *, struct uwb_mac_addr *); -int __uwb_mac_addr_assigned_check(struct device *, void *); -int __uwb_dev_addr_assigned_check(struct device *, void *); - -/* Print in @buf a pretty repr of @addr */ -static inline size_t uwb_dev_addr_print(char *buf, size_t buf_size, - const struct uwb_dev_addr *addr) -{ - return __uwb_addr_print(buf, buf_size, addr->data, 0); -} - -/* Print in @buf a pretty repr of @addr */ -static inline size_t uwb_mac_addr_print(char *buf, size_t buf_size, - const struct uwb_mac_addr *addr) -{ - return __uwb_addr_print(buf, buf_size, addr->data, 1); -} - -/* @returns 0 if device addresses @addr2 and @addr1 are equal */ -static inline int uwb_dev_addr_cmp(const struct uwb_dev_addr *addr1, - const struct uwb_dev_addr *addr2) -{ - return memcmp(addr1, addr2, sizeof(*addr1)); -} - -/* @returns 0 if MAC addresses @addr2 and @addr1 are equal */ -static inline int uwb_mac_addr_cmp(const struct uwb_mac_addr *addr1, - const struct uwb_mac_addr *addr2) -{ - return memcmp(addr1, addr2, sizeof(*addr1)); -} - -/* @returns !0 if a MAC @addr is a broadcast address */ -static inline int uwb_mac_addr_bcast(const struct uwb_mac_addr *addr) -{ - struct uwb_mac_addr bcast = { - .data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } - }; - return !uwb_mac_addr_cmp(addr, &bcast); -} - -/* @returns !0 if a MAC @addr is all zeroes*/ -static inline int uwb_mac_addr_unset(const struct uwb_mac_addr *addr) -{ - struct uwb_mac_addr unset = { - .data = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } - }; - return !uwb_mac_addr_cmp(addr, &unset); -} - -/* @returns !0 if the address is in use. */ -static inline unsigned __uwb_dev_addr_assigned(struct uwb_rc *rc, - struct uwb_dev_addr *addr) -{ - return uwb_dev_for_each(rc, __uwb_dev_addr_assigned_check, addr); -} - -/* - * UWB Radio Controller API - * - * This API is used (in addition to the general API) to implement UWB - * Radio Controllers. - */ -void uwb_rc_init(struct uwb_rc *); -int uwb_rc_add(struct uwb_rc *, struct device *dev, void *rc_priv); -void uwb_rc_rm(struct uwb_rc *); -void uwb_rc_neh_grok(struct uwb_rc *, void *, size_t); -void uwb_rc_neh_error(struct uwb_rc *, int); -void uwb_rc_reset_all(struct uwb_rc *rc); -void uwb_rc_pre_reset(struct uwb_rc *rc); -int uwb_rc_post_reset(struct uwb_rc *rc); - -/** - * uwb_rsv_is_owner - is the owner of this reservation the RC? - * @rsv: the reservation - */ -static inline bool uwb_rsv_is_owner(struct uwb_rsv *rsv) -{ - return rsv->owner == &rsv->rc->uwb_dev; -} - -/** - * enum uwb_notifs - UWB events that can be passed to any listeners - * @UWB_NOTIF_ONAIR: a new neighbour has joined the beacon group. - * @UWB_NOTIF_OFFAIR: a neighbour has left the beacon group. - * - * Higher layers can register callback functions with the radio - * controller using uwb_notifs_register(). The radio controller - * maintains a list of all registered handlers and will notify all - * nodes when an event occurs. - */ -enum uwb_notifs { - UWB_NOTIF_ONAIR, - UWB_NOTIF_OFFAIR, -}; - -/* Callback function registered with UWB */ -struct uwb_notifs_handler { - struct list_head list_node; - void (*cb)(void *, struct uwb_dev *, enum uwb_notifs); - void *data; -}; - -int uwb_notifs_register(struct uwb_rc *, struct uwb_notifs_handler *); -int uwb_notifs_deregister(struct uwb_rc *, struct uwb_notifs_handler *); - - -/** - * UWB radio controller Event Size Entry (for creating entry tables) - * - * WUSB and WHCI define events and notifications, and they might have - * fixed or variable size. - * - * Each event/notification has a size which is not necessarily known - * in advance based on the event code. As well, vendor specific - * events/notifications will have a size impossible to determine - * unless we know about the device's specific details. - * - * It was way too smart of the spec writers not to think that it would - * be impossible for a generic driver to skip over vendor specific - * events/notifications if there are no LENGTH fields in the HEADER of - * each message...the transaction size cannot be counted on as the - * spec does not forbid to pack more than one event in a single - * transaction. - * - * Thus, we guess sizes with tables (or for events, when you know the - * size ahead of time you can use uwb_rc_neh_extra_size*()). We - * register tables with the known events and their sizes, and then we - * traverse those tables. For those with variable length, we provide a - * way to lookup the size inside the event/notification's - * payload. This allows device-specific event size tables to be - * registered. - * - * @size: Size of the payload - * - * @offset: if != 0, at offset @offset-1 starts a field with a length - * that has to be added to @size. The format of the field is - * given by @type. - * - * @type: Type and length of the offset field. Most common is LE 16 - * bits (that's why that is zero); others are there mostly to - * cover for bugs and weirdos. - */ -struct uwb_est_entry { - size_t size; - unsigned offset; - enum { UWB_EST_16 = 0, UWB_EST_8 = 1 } type; -}; - -int uwb_est_register(u8 type, u8 code_high, u16 vendor, u16 product, - const struct uwb_est_entry *, size_t entries); -int uwb_est_unregister(u8 type, u8 code_high, u16 vendor, u16 product, - const struct uwb_est_entry *, size_t entries); -ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb, - size_t len); - -/* -- Misc */ - -enum { - EDC_MAX_ERRORS = 10, - EDC_ERROR_TIMEFRAME = HZ, -}; - -/* error density counter */ -struct edc { - unsigned long timestart; - u16 errorcount; -}; - -static inline -void edc_init(struct edc *edc) -{ - edc->timestart = jiffies; -} - -/* Called when an error occurred. - * This is way to determine if the number of acceptable errors per time - * period has been exceeded. It is not accurate as there are cases in which - * this scheme will not work, for example if there are periodic occurrences - * of errors that straddle updates to the start time. This scheme is - * sufficient for our usage. - * - * @returns 1 if maximum acceptable errors per timeframe has been exceeded. - */ -static inline int edc_inc(struct edc *err_hist, u16 max_err, u16 timeframe) -{ - unsigned long now; - - now = jiffies; - if (now - err_hist->timestart > timeframe) { - err_hist->errorcount = 1; - err_hist->timestart = now; - } else if (++err_hist->errorcount > max_err) { - err_hist->errorcount = 0; - err_hist->timestart = now; - return 1; - } - return 0; -} - - -/* Information Element handling */ - -struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len); -int uwb_rc_ie_add(struct uwb_rc *uwb_rc, const struct uwb_ie_hdr *ies, size_t size); -int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id); - -/* - * Transmission statistics - * - * UWB uses LQI and RSSI (one byte values) for reporting radio signal - * strength and line quality indication. We do quick and dirty - * averages of those. They are signed values, btw. - * - * For 8 bit quantities, we keep the min, the max, an accumulator - * (@sigma) and a # of samples. When @samples gets to 255, we compute - * the average (@sigma / @samples), place it in @sigma and reset - * @samples to 1 (so we use it as the first sample). - * - * Now, statistically speaking, probably I am kicking the kidneys of - * some books I have in my shelves collecting dust, but I just want to - * get an approx, not the Nobel. - * - * LOCKING: there is no locking per se, but we try to keep a lockless - * schema. Only _add_samples() modifies the values--as long as you - * have other locking on top that makes sure that no two calls of - * _add_sample() happen at the same time, then we are fine. Now, for - * resetting the values we just set @samples to 0 and that makes the - * next _add_sample() to start with defaults. Reading the values in - * _show() currently can race, so you need to make sure the calls are - * under the same lock that protects calls to _add_sample(). FIXME: - * currently unlocked (It is not ultraprecise but does the trick. Bite - * me). - */ -struct stats { - s8 min, max; - s16 sigma; - atomic_t samples; -}; - -static inline -void stats_init(struct stats *stats) -{ - atomic_set(&stats->samples, 0); - wmb(); -} - -static inline -void stats_add_sample(struct stats *stats, s8 sample) -{ - s8 min, max; - s16 sigma; - unsigned samples = atomic_read(&stats->samples); - if (samples == 0) { /* it was zero before, so we initialize */ - min = 127; - max = -128; - sigma = 0; - } else { - min = stats->min; - max = stats->max; - sigma = stats->sigma; - } - - if (sample < min) /* compute new values */ - min = sample; - else if (sample > max) - max = sample; - sigma += sample; - - stats->min = min; /* commit */ - stats->max = max; - stats->sigma = sigma; - if (atomic_add_return(1, &stats->samples) > 255) { - /* wrapped around! reset */ - stats->sigma = sigma / 256; - atomic_set(&stats->samples, 1); - } -} - -static inline ssize_t stats_show(struct stats *stats, char *buf) -{ - int min, max, avg; - int samples = atomic_read(&stats->samples); - if (samples == 0) - min = max = avg = 0; - else { - min = stats->min; - max = stats->max; - avg = stats->sigma / samples; - } - return scnprintf(buf, PAGE_SIZE, "%d %d %d\n", min, max, avg); -} - -static inline ssize_t stats_store(struct stats *stats, const char *buf, - size_t size) -{ - stats_init(stats); - return size; -} - -#endif /* #ifndef __LINUX__UWB_H__ */ |