summaryrefslogtreecommitdiff
path: root/drivers/staging/uwb/neh.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/staging/uwb/neh.c')
-rw-r--r--drivers/staging/uwb/neh.c606
1 files changed, 0 insertions, 606 deletions
diff --git a/drivers/staging/uwb/neh.c b/drivers/staging/uwb/neh.c
deleted file mode 100644
index 1695584be412..000000000000
--- a/drivers/staging/uwb/neh.c
+++ /dev/null
@@ -1,606 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * WUSB Wire Adapter: Radio Control Interface (WUSB[8])
- * Notification and Event Handling
- *
- * Copyright (C) 2005-2006 Intel Corporation
- * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
- *
- * The RC interface of the Host Wire Adapter (USB dongle) or WHCI PCI
- * card delivers a stream of notifications and events to the
- * notification end event endpoint or area. This code takes care of
- * getting a buffer with that data, breaking it up in separate
- * notifications and events and then deliver those.
- *
- * Events are answers to commands and they carry a context ID that
- * associates them to the command. Notifications are that,
- * notifications, they come out of the blue and have a context ID of
- * zero. Think of the context ID kind of like a handler. The
- * uwb_rc_neh_* code deals with managing context IDs.
- *
- * This is why you require a handle to operate on a UWB host. When you
- * open a handle a context ID is assigned to you.
- *
- * So, as it is done is:
- *
- * 1. Add an event handler [uwb_rc_neh_add()] (assigns a ctx id)
- * 2. Issue command [rc->cmd(rc, ...)]
- * 3. Arm the timeout timer [uwb_rc_neh_arm()]
- * 4, Release the reference to the neh [uwb_rc_neh_put()]
- * 5. Wait for the callback
- * 6. Command result (RCEB) is passed to the callback
- *
- * If (2) fails, you should remove the handle [uwb_rc_neh_rm()]
- * instead of arming the timer.
- *
- * Handles are for using in *serialized* code, single thread.
- *
- * When the notification/event comes, the IRQ handler/endpoint
- * callback passes the data read to uwb_rc_neh_grok() which will break
- * it up in a discrete series of events, look up who is listening for
- * them and execute the pertinent callbacks.
- *
- * If the reader detects an error while reading the data stream, call
- * uwb_rc_neh_error().
- *
- * CONSTRAINTS/ASSUMPTIONS:
- *
- * - Most notifications/events are small (less thank .5k), copying
- * around is ok.
- *
- * - Notifications/events are ALWAYS smaller than PAGE_SIZE
- *
- * - Notifications/events always come in a single piece (ie: a buffer
- * will always contain entire notifications/events).
- *
- * - we cannot know in advance how long each event is (because they
- * lack a length field in their header--smart move by the standards
- * body, btw). So we need a facility to get the event size given the
- * header. This is what the EST code does (notif/Event Size
- * Tables), check nest.c--as well, you can associate the size to
- * the handle [w/ neh->extra_size()].
- *
- * - Most notifications/events are fixed size; only a few are variable
- * size (NEST takes care of that).
- *
- * - Listeners of events expect them, so they usually provide a
- * buffer, as they know the size. Listeners to notifications don't,
- * so we allocate their buffers dynamically.
- */
-#include <linux/kernel.h>
-#include <linux/timer.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/export.h>
-
-#include "uwb-internal.h"
-
-/*
- * UWB Radio Controller Notification/Event Handle
- *
- * Represents an entity waiting for an event coming from the UWB Radio
- * Controller with a given context id (context) and type (evt_type and
- * evt). On reception of the notification/event, the callback (cb) is
- * called with the event.
- *
- * If the timer expires before the event is received, the callback is
- * called with -ETIMEDOUT as the event size.
- */
-struct uwb_rc_neh {
- struct kref kref;
-
- struct uwb_rc *rc;
- u8 evt_type;
- __le16 evt;
- u8 context;
- u8 completed;
- uwb_rc_cmd_cb_f cb;
- void *arg;
-
- struct timer_list timer;
- struct list_head list_node;
-};
-
-static void uwb_rc_neh_timer(struct timer_list *t);
-
-static void uwb_rc_neh_release(struct kref *kref)
-{
- struct uwb_rc_neh *neh = container_of(kref, struct uwb_rc_neh, kref);
-
- kfree(neh);
-}
-
-static void uwb_rc_neh_get(struct uwb_rc_neh *neh)
-{
- kref_get(&neh->kref);
-}
-
-/**
- * uwb_rc_neh_put - release reference to a neh
- * @neh: the neh
- */
-void uwb_rc_neh_put(struct uwb_rc_neh *neh)
-{
- kref_put(&neh->kref, uwb_rc_neh_release);
-}
-
-
-/**
- * Assigns @neh a context id from @rc's pool
- *
- * @rc: UWB Radio Controller descriptor; @rc->neh_lock taken
- * @neh: Notification/Event Handle
- * @returns 0 if context id was assigned ok; < 0 errno on error (if
- * all the context IDs are taken).
- *
- * (assumes @wa is locked).
- *
- * NOTE: WUSB spec reserves context ids 0x00 for notifications and
- * 0xff is invalid, so they must not be used. Initialization
- * fills up those two in the bitmap so they are not allocated.
- *
- * We spread the allocation around to reduce the possibility of two
- * consecutive opened @neh's getting the same context ID assigned (to
- * avoid surprises with late events that timed out long time ago). So
- * first we search from where @rc->ctx_roll is, if not found, we
- * search from zero.
- */
-static
-int __uwb_rc_ctx_get(struct uwb_rc *rc, struct uwb_rc_neh *neh)
-{
- int result;
- result = find_next_zero_bit(rc->ctx_bm, UWB_RC_CTX_MAX,
- rc->ctx_roll++);
- if (result < UWB_RC_CTX_MAX)
- goto found;
- result = find_first_zero_bit(rc->ctx_bm, UWB_RC_CTX_MAX);
- if (result < UWB_RC_CTX_MAX)
- goto found;
- return -ENFILE;
-found:
- set_bit(result, rc->ctx_bm);
- neh->context = result;
- return 0;
-}
-
-
-/** Releases @neh's context ID back to @rc (@rc->neh_lock is locked). */
-static
-void __uwb_rc_ctx_put(struct uwb_rc *rc, struct uwb_rc_neh *neh)
-{
- struct device *dev = &rc->uwb_dev.dev;
- if (neh->context == 0)
- return;
- if (test_bit(neh->context, rc->ctx_bm) == 0) {
- dev_err(dev, "context %u not set in bitmap\n",
- neh->context);
- WARN_ON(1);
- }
- clear_bit(neh->context, rc->ctx_bm);
- neh->context = 0;
-}
-
-/**
- * uwb_rc_neh_add - add a neh for a radio controller command
- * @rc: the radio controller
- * @cmd: the radio controller command
- * @expected_type: the type of the expected response event
- * @expected_event: the expected event ID
- * @cb: callback for when the event is received
- * @arg: argument for the callback
- *
- * Creates a neh and adds it to the list of those waiting for an
- * event. A context ID will be assigned to the command.
- */
-struct uwb_rc_neh *uwb_rc_neh_add(struct uwb_rc *rc, struct uwb_rccb *cmd,
- u8 expected_type, u16 expected_event,
- uwb_rc_cmd_cb_f cb, void *arg)
-{
- int result;
- unsigned long flags;
- struct device *dev = &rc->uwb_dev.dev;
- struct uwb_rc_neh *neh;
-
- neh = kzalloc(sizeof(*neh), GFP_KERNEL);
- if (neh == NULL) {
- result = -ENOMEM;
- goto error_kzalloc;
- }
-
- kref_init(&neh->kref);
- INIT_LIST_HEAD(&neh->list_node);
- timer_setup(&neh->timer, uwb_rc_neh_timer, 0);
-
- neh->rc = rc;
- neh->evt_type = expected_type;
- neh->evt = cpu_to_le16(expected_event);
- neh->cb = cb;
- neh->arg = arg;
-
- spin_lock_irqsave(&rc->neh_lock, flags);
- result = __uwb_rc_ctx_get(rc, neh);
- if (result >= 0) {
- cmd->bCommandContext = neh->context;
- list_add_tail(&neh->list_node, &rc->neh_list);
- uwb_rc_neh_get(neh);
- }
- spin_unlock_irqrestore(&rc->neh_lock, flags);
- if (result < 0)
- goto error_ctx_get;
-
- return neh;
-
-error_ctx_get:
- kfree(neh);
-error_kzalloc:
- dev_err(dev, "cannot open handle to radio controller: %d\n", result);
- return ERR_PTR(result);
-}
-
-static void __uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
-{
- __uwb_rc_ctx_put(rc, neh);
- list_del(&neh->list_node);
-}
-
-/**
- * uwb_rc_neh_rm - remove a neh.
- * @rc: the radio controller
- * @neh: the neh to remove
- *
- * Remove an active neh immediately instead of waiting for the event
- * (or a time out).
- */
-void uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&rc->neh_lock, flags);
- __uwb_rc_neh_rm(rc, neh);
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-
- del_timer_sync(&neh->timer);
- uwb_rc_neh_put(neh);
-}
-
-/**
- * uwb_rc_neh_arm - arm an event handler timeout timer
- *
- * @rc: UWB Radio Controller
- * @neh: Notification/event handler for @rc
- *
- * The timer is only armed if the neh is active.
- */
-void uwb_rc_neh_arm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&rc->neh_lock, flags);
- if (neh->context)
- mod_timer(&neh->timer,
- jiffies + msecs_to_jiffies(UWB_RC_CMD_TIMEOUT_MS));
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-}
-
-static void uwb_rc_neh_cb(struct uwb_rc_neh *neh, struct uwb_rceb *rceb, size_t size)
-{
- (*neh->cb)(neh->rc, neh->arg, rceb, size);
- uwb_rc_neh_put(neh);
-}
-
-static bool uwb_rc_neh_match(struct uwb_rc_neh *neh, const struct uwb_rceb *rceb)
-{
- return neh->evt_type == rceb->bEventType
- && neh->evt == rceb->wEvent
- && neh->context == rceb->bEventContext;
-}
-
-/**
- * Find the handle waiting for a RC Radio Control Event
- *
- * @rc: UWB Radio Controller
- * @rceb: Pointer to the RCEB buffer
- * @event_size: Pointer to the size of the RCEB buffer. Might be
- * adjusted to take into account the @neh->extra_size
- * settings.
- *
- * If the listener has no buffer (NULL buffer), one is allocated for
- * the right size (the amount of data received). @neh->ptr will point
- * to the event payload, which always starts with a 'struct
- * uwb_rceb'. kfree() it when done.
- */
-static
-struct uwb_rc_neh *uwb_rc_neh_lookup(struct uwb_rc *rc,
- const struct uwb_rceb *rceb)
-{
- struct uwb_rc_neh *neh = NULL, *h;
- unsigned long flags;
-
- spin_lock_irqsave(&rc->neh_lock, flags);
-
- list_for_each_entry(h, &rc->neh_list, list_node) {
- if (uwb_rc_neh_match(h, rceb)) {
- neh = h;
- break;
- }
- }
-
- if (neh)
- __uwb_rc_neh_rm(rc, neh);
-
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-
- return neh;
-}
-
-
-/*
- * Process notifications coming from the radio control interface
- *
- * @rc: UWB Radio Control Interface descriptor
- * @neh: Notification/Event Handler @neh->ptr points to
- * @uwb_evt->buffer.
- *
- * This function is called by the event/notif handling subsystem when
- * notifications arrive (hwarc_probe() arms a notification/event handle
- * that calls back this function for every received notification; this
- * function then will rearm itself).
- *
- * Notification data buffers are dynamically allocated by the NEH
- * handling code in neh.c [uwb_rc_neh_lookup()]. What is actually
- * allocated is space to contain the notification data.
- *
- * Buffers are prefixed with a Radio Control Event Block (RCEB) as
- * defined by the WUSB Wired-Adapter Radio Control interface. We
- * just use it for the notification code.
- *
- * On each case statement we just transcode endianess of the different
- * fields. We declare a pointer to a RCI definition of an event, and
- * then to a UWB definition of the same event (which are the same,
- * remember). Event if we use different pointers
- */
-static
-void uwb_rc_notif(struct uwb_rc *rc, struct uwb_rceb *rceb, ssize_t size)
-{
- struct device *dev = &rc->uwb_dev.dev;
- struct uwb_event *uwb_evt;
-
- if (size == -ESHUTDOWN)
- return;
- if (size < 0) {
- dev_err(dev, "ignoring event with error code %zu\n",
- size);
- return;
- }
-
- uwb_evt = kzalloc(sizeof(*uwb_evt), GFP_ATOMIC);
- if (unlikely(uwb_evt == NULL)) {
- dev_err(dev, "no memory to queue event 0x%02x/%04x/%02x\n",
- rceb->bEventType, le16_to_cpu(rceb->wEvent),
- rceb->bEventContext);
- return;
- }
- uwb_evt->rc = __uwb_rc_get(rc); /* will be put by uwbd's uwbd_event_handle() */
- uwb_evt->ts_jiffies = jiffies;
- uwb_evt->type = UWB_EVT_TYPE_NOTIF;
- uwb_evt->notif.size = size;
- uwb_evt->notif.rceb = rceb;
-
- uwbd_event_queue(uwb_evt);
-}
-
-static void uwb_rc_neh_grok_event(struct uwb_rc *rc, struct uwb_rceb *rceb, size_t size)
-{
- struct device *dev = &rc->uwb_dev.dev;
- struct uwb_rc_neh *neh;
- struct uwb_rceb *notif;
- unsigned long flags;
-
- if (rceb->bEventContext == 0) {
- notif = kmalloc(size, GFP_ATOMIC);
- if (notif) {
- memcpy(notif, rceb, size);
- uwb_rc_notif(rc, notif, size);
- } else
- dev_err(dev, "event 0x%02x/%04x/%02x (%zu bytes): no memory\n",
- rceb->bEventType, le16_to_cpu(rceb->wEvent),
- rceb->bEventContext, size);
- } else {
- neh = uwb_rc_neh_lookup(rc, rceb);
- if (neh) {
- spin_lock_irqsave(&rc->neh_lock, flags);
- /* to guard against a timeout */
- neh->completed = 1;
- del_timer(&neh->timer);
- spin_unlock_irqrestore(&rc->neh_lock, flags);
- uwb_rc_neh_cb(neh, rceb, size);
- } else
- dev_warn(dev, "event 0x%02x/%04x/%02x (%zu bytes): nobody cared\n",
- rceb->bEventType, le16_to_cpu(rceb->wEvent),
- rceb->bEventContext, size);
- }
-}
-
-/**
- * Given a buffer with one or more UWB RC events/notifications, break
- * them up and dispatch them.
- *
- * @rc: UWB Radio Controller
- * @buf: Buffer with the stream of notifications/events
- * @buf_size: Amount of data in the buffer
- *
- * Note each notification/event starts always with a 'struct
- * uwb_rceb', so the minimum size if 4 bytes.
- *
- * The device may pass us events formatted differently than expected.
- * These are first filtered, potentially creating a new event in a new
- * memory location. If a new event is created by the filter it is also
- * freed here.
- *
- * For each notif/event, tries to guess the size looking at the EST
- * tables, then looks for a neh that is waiting for that event and if
- * found, copies the payload to the neh's buffer and calls it back. If
- * not, the data is ignored.
- *
- * Note that if we can't find a size description in the EST tables, we
- * still might find a size in the 'neh' handle in uwb_rc_neh_lookup().
- *
- * Assumptions:
- *
- * @rc->neh_lock is NOT taken
- *
- * We keep track of various sizes here:
- * size: contains the size of the buffer that is processed for the
- * incoming event. this buffer may contain events that are not
- * formatted as WHCI.
- * real_size: the actual space taken by this event in the buffer.
- * We need to keep track of the real size of an event to be able to
- * advance the buffer correctly.
- * event_size: the size of the event as expected by the core layer
- * [OR] the size of the event after filtering. if the filtering
- * created a new event in a new memory location then this is
- * effectively the size of a new event buffer
- */
-void uwb_rc_neh_grok(struct uwb_rc *rc, void *buf, size_t buf_size)
-{
- struct device *dev = &rc->uwb_dev.dev;
- void *itr;
- struct uwb_rceb *rceb;
- size_t size, real_size, event_size;
- int needtofree;
-
- itr = buf;
- size = buf_size;
- while (size > 0) {
- if (size < sizeof(*rceb)) {
- dev_err(dev, "not enough data in event buffer to "
- "process incoming events (%zu left, minimum is "
- "%zu)\n", size, sizeof(*rceb));
- break;
- }
-
- rceb = itr;
- if (rc->filter_event) {
- needtofree = rc->filter_event(rc, &rceb, size,
- &real_size, &event_size);
- if (needtofree < 0 && needtofree != -ENOANO) {
- dev_err(dev, "BUG: Unable to filter event "
- "(0x%02x/%04x/%02x) from "
- "device. \n", rceb->bEventType,
- le16_to_cpu(rceb->wEvent),
- rceb->bEventContext);
- break;
- }
- } else
- needtofree = -ENOANO;
- /* do real processing if there was no filtering or the
- * filtering didn't act */
- if (needtofree == -ENOANO) {
- ssize_t ret = uwb_est_find_size(rc, rceb, size);
- if (ret < 0)
- break;
- if (ret > size) {
- dev_err(dev, "BUG: hw sent incomplete event "
- "0x%02x/%04x/%02x (%zd bytes), only got "
- "%zu bytes. We don't handle that.\n",
- rceb->bEventType, le16_to_cpu(rceb->wEvent),
- rceb->bEventContext, ret, size);
- break;
- }
- real_size = event_size = ret;
- }
- uwb_rc_neh_grok_event(rc, rceb, event_size);
-
- if (needtofree == 1)
- kfree(rceb);
-
- itr += real_size;
- size -= real_size;
- }
-}
-EXPORT_SYMBOL_GPL(uwb_rc_neh_grok);
-
-
-/**
- * The entity that reads from the device notification/event channel has
- * detected an error.
- *
- * @rc: UWB Radio Controller
- * @error: Errno error code
- *
- */
-void uwb_rc_neh_error(struct uwb_rc *rc, int error)
-{
- struct uwb_rc_neh *neh;
- unsigned long flags;
-
- for (;;) {
- spin_lock_irqsave(&rc->neh_lock, flags);
- if (list_empty(&rc->neh_list)) {
- spin_unlock_irqrestore(&rc->neh_lock, flags);
- break;
- }
- neh = list_first_entry(&rc->neh_list, struct uwb_rc_neh, list_node);
- __uwb_rc_neh_rm(rc, neh);
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-
- del_timer_sync(&neh->timer);
- uwb_rc_neh_cb(neh, NULL, error);
- }
-}
-EXPORT_SYMBOL_GPL(uwb_rc_neh_error);
-
-
-static void uwb_rc_neh_timer(struct timer_list *t)
-{
- struct uwb_rc_neh *neh = from_timer(neh, t, timer);
- struct uwb_rc *rc = neh->rc;
- unsigned long flags;
-
- spin_lock_irqsave(&rc->neh_lock, flags);
- if (neh->completed) {
- spin_unlock_irqrestore(&rc->neh_lock, flags);
- return;
- }
- if (neh->context)
- __uwb_rc_neh_rm(rc, neh);
- else
- neh = NULL;
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-
- if (neh)
- uwb_rc_neh_cb(neh, NULL, -ETIMEDOUT);
-}
-
-/** Initializes the @rc's neh subsystem
- */
-void uwb_rc_neh_create(struct uwb_rc *rc)
-{
- spin_lock_init(&rc->neh_lock);
- INIT_LIST_HEAD(&rc->neh_list);
- set_bit(0, rc->ctx_bm); /* 0 is reserved (see [WUSB] table 8-65) */
- set_bit(0xff, rc->ctx_bm); /* and 0xff is invalid */
- rc->ctx_roll = 1;
-}
-
-
-/** Release's the @rc's neh subsystem */
-void uwb_rc_neh_destroy(struct uwb_rc *rc)
-{
- unsigned long flags;
- struct uwb_rc_neh *neh;
-
- for (;;) {
- spin_lock_irqsave(&rc->neh_lock, flags);
- if (list_empty(&rc->neh_list)) {
- spin_unlock_irqrestore(&rc->neh_lock, flags);
- break;
- }
- neh = list_first_entry(&rc->neh_list, struct uwb_rc_neh, list_node);
- __uwb_rc_neh_rm(rc, neh);
- spin_unlock_irqrestore(&rc->neh_lock, flags);
-
- del_timer_sync(&neh->timer);
- uwb_rc_neh_put(neh);
- }
-}
generated by cgit (git 2.34.1) at 2024-05-10 06:13:16 +0000