cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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notif-wait.c (3593B)

      1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
      2/*
      3 * Copyright (C) 2005-2014, 2021 Intel Corporation
      4 * Copyright (C) 2015-2017 Intel Deutschland GmbH
      5 */
      6#include <linux/sched.h>
      7#include <linux/export.h>
      8
      9#include "iwl-drv.h"
     10#include "notif-wait.h"
     11
     12
     13void iwl_notification_wait_init(struct iwl_notif_wait_data *notif_wait)
     14{
     15	spin_lock_init(&notif_wait->notif_wait_lock);
     16	INIT_LIST_HEAD(&notif_wait->notif_waits);
     17	init_waitqueue_head(&notif_wait->notif_waitq);
     18}
     19IWL_EXPORT_SYMBOL(iwl_notification_wait_init);
     20
     21bool iwl_notification_wait(struct iwl_notif_wait_data *notif_wait,
     22			   struct iwl_rx_packet *pkt)
     23{
     24	bool triggered = false;
     25
     26	if (!list_empty(&notif_wait->notif_waits)) {
     27		struct iwl_notification_wait *w;
     28
     29		spin_lock_bh(&notif_wait->notif_wait_lock);
     30		list_for_each_entry(w, &notif_wait->notif_waits, list) {
     31			int i;
     32			bool found = false;
     33
     34			/*
     35			 * If it already finished (triggered) or has been
     36			 * aborted then don't evaluate it again to avoid races,
     37			 * Otherwise the function could be called again even
     38			 * though it returned true before
     39			 */
     40			if (w->triggered || w->aborted)
     41				continue;
     42
     43			for (i = 0; i < w->n_cmds; i++) {
     44				u16 rec_id = WIDE_ID(pkt->hdr.group_id,
     45						     pkt->hdr.cmd);
     46
     47				if (w->cmds[i] == rec_id ||
     48				    (!iwl_cmd_groupid(w->cmds[i]) &&
     49				     DEF_ID(w->cmds[i]) == rec_id)) {
     50					found = true;
     51					break;
     52				}
     53			}
     54			if (!found)
     55				continue;
     56
     57			if (!w->fn || w->fn(notif_wait, pkt, w->fn_data)) {
     58				w->triggered = true;
     59				triggered = true;
     60			}
     61		}
     62		spin_unlock_bh(&notif_wait->notif_wait_lock);
     63	}
     64
     65	return triggered;
     66}
     67IWL_EXPORT_SYMBOL(iwl_notification_wait);
     68
     69void iwl_abort_notification_waits(struct iwl_notif_wait_data *notif_wait)
     70{
     71	struct iwl_notification_wait *wait_entry;
     72
     73	spin_lock_bh(&notif_wait->notif_wait_lock);
     74	list_for_each_entry(wait_entry, &notif_wait->notif_waits, list)
     75		wait_entry->aborted = true;
     76	spin_unlock_bh(&notif_wait->notif_wait_lock);
     77
     78	wake_up_all(&notif_wait->notif_waitq);
     79}
     80IWL_EXPORT_SYMBOL(iwl_abort_notification_waits);
     81
     82void
     83iwl_init_notification_wait(struct iwl_notif_wait_data *notif_wait,
     84			   struct iwl_notification_wait *wait_entry,
     85			   const u16 *cmds, int n_cmds,
     86			   bool (*fn)(struct iwl_notif_wait_data *notif_wait,
     87				      struct iwl_rx_packet *pkt, void *data),
     88			   void *fn_data)
     89{
     90	if (WARN_ON(n_cmds > MAX_NOTIF_CMDS))
     91		n_cmds = MAX_NOTIF_CMDS;
     92
     93	wait_entry->fn = fn;
     94	wait_entry->fn_data = fn_data;
     95	wait_entry->n_cmds = n_cmds;
     96	memcpy(wait_entry->cmds, cmds, n_cmds * sizeof(u16));
     97	wait_entry->triggered = false;
     98	wait_entry->aborted = false;
     99
    100	spin_lock_bh(&notif_wait->notif_wait_lock);
    101	list_add(&wait_entry->list, &notif_wait->notif_waits);
    102	spin_unlock_bh(&notif_wait->notif_wait_lock);
    103}
    104IWL_EXPORT_SYMBOL(iwl_init_notification_wait);
    105
    106void iwl_remove_notification(struct iwl_notif_wait_data *notif_wait,
    107			     struct iwl_notification_wait *wait_entry)
    108{
    109	spin_lock_bh(&notif_wait->notif_wait_lock);
    110	list_del(&wait_entry->list);
    111	spin_unlock_bh(&notif_wait->notif_wait_lock);
    112}
    113IWL_EXPORT_SYMBOL(iwl_remove_notification);
    114
    115int iwl_wait_notification(struct iwl_notif_wait_data *notif_wait,
    116			  struct iwl_notification_wait *wait_entry,
    117			  unsigned long timeout)
    118{
    119	int ret;
    120
    121	ret = wait_event_timeout(notif_wait->notif_waitq,
    122				 wait_entry->triggered || wait_entry->aborted,
    123				 timeout);
    124
    125	iwl_remove_notification(notif_wait, wait_entry);
    126
    127	if (wait_entry->aborted)
    128		return -EIO;
    129
    130	/* return value is always >= 0 */
    131	if (ret <= 0)
    132		return -ETIMEDOUT;
    133	return 0;
    134}
    135IWL_EXPORT_SYMBOL(iwl_wait_notification);