From e1781ed33a8809c58ad6c3b6d432d656446efa43 Mon Sep 17 00:00:00 2001 From: Kalle Valo Date: Wed, 23 Dec 2009 13:15:47 +0100 Subject: [PATCH] mac80211: annotate sleeping driver ops To make it easier to notice cases of calling sleeping ops in atomic context, annotate driver-ops.h with appropiate might_sleep() calls. At the same time, also document in mac80211.h the op functions with missing contexts. mac80211 doesn't seem to use get_tx_stats anywhere currently. Just to be on the safe side, I documented it to be atomic, but hopefully the op can be removed in the future. Compile-tested only. Signed-off-by: Kalle Valo Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- include/net/mac80211.h | 43 ++++++++++++++++++++-------- net/mac80211/driver-ops.h | 60 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 87 insertions(+), 16 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 08d41357dcbe..5ee666ae4c88 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1383,7 +1383,7 @@ enum ieee80211_ampdu_mlme_action { * When the device is started it should not have a MAC address * to avoid acknowledging frames before a non-monitor device * is added. - * Must be implemented. + * Must be implemented and can sleep. * * @stop: Called after last netdevice attached to the hardware * is disabled. This should turn off the hardware (at least @@ -1391,7 +1391,7 @@ enum ieee80211_ampdu_mlme_action { * May be called right after add_interface if that rejects * an interface. If you added any work onto the mac80211 workqueue * you should ensure to cancel it on this callback. - * Must be implemented. + * Must be implemented and can sleep. * * @add_interface: Called when a netdevice attached to the hardware is * enabled. Because it is not called for monitor mode devices, @start @@ -1401,7 +1401,7 @@ enum ieee80211_ampdu_mlme_action { * interface is given in the conf parameter. * The callback may refuse to add an interface by returning a * negative error code (which will be seen in userspace.) - * Must be implemented. + * Must be implemented and can sleep. * * @remove_interface: Notifies a driver that an interface is going down. * The @stop callback is called after this if it is the last interface @@ -1410,19 +1410,20 @@ enum ieee80211_ampdu_mlme_action { * must be cleared so the device no longer acknowledges packets, * the mac_addr member of the conf structure is, however, set to the * MAC address of the device going away. - * Hence, this callback must be implemented. + * Hence, this callback must be implemented. It can sleep. * * @config: Handler for configuration requests. IEEE 802.11 code calls this * function to change hardware configuration, e.g., channel. * This function should never fail but returns a negative error code - * if it does. + * if it does. The callback can sleep. * * @bss_info_changed: Handler for configuration requests related to BSS * parameters that may vary during BSS's lifespan, and may affect low * level driver (e.g. assoc/disassoc status, erp parameters). * This function should not be used if no BSS has been set, unless * for association indication. The @changed parameter indicates which - * of the bss parameters has changed when a call is made. + * of the bss parameters has changed when a call is made. The callback + * can sleep. * * @prepare_multicast: Prepare for multicast filter configuration. * This callback is optional, and its return value is passed @@ -1430,20 +1431,22 @@ enum ieee80211_ampdu_mlme_action { * * @configure_filter: Configure the device's RX filter. * See the section "Frame filtering" for more information. - * This callback must be implemented. + * This callback must be implemented and can sleep. * * @set_tim: Set TIM bit. mac80211 calls this function when a TIM bit * must be set or cleared for a given STA. Must be atomic. * * @set_key: See the section "Hardware crypto acceleration" - * This callback can sleep, and is only called between add_interface - * and remove_interface calls, i.e. while the given virtual interface + * This callback is only called between add_interface and + * remove_interface calls, i.e. while the given virtual interface * is enabled. * Returns a negative error code if the key can't be added. + * The callback can sleep. * * @update_tkip_key: See the section "Hardware crypto acceleration" * This callback will be called in the context of Rx. Called for drivers * which set IEEE80211_KEY_FLAG_TKIP_REQ_RX_P1_KEY. + * The callback can sleep. * * @hw_scan: Ask the hardware to service the scan request, no need to start * the scan state machine in stack. The scan must honour the channel @@ -1457,21 +1460,28 @@ enum ieee80211_ampdu_mlme_action { * When the scan finishes, ieee80211_scan_completed() must be called; * note that it also must be called when the scan cannot finish due to * any error unless this callback returned a negative error code. + * The callback can sleep. * * @sw_scan_start: Notifier function that is called just before a software scan * is started. Can be NULL, if the driver doesn't need this notification. + * The callback can sleep. * - * @sw_scan_complete: Notifier function that is called just after a software scan - * finished. Can be NULL, if the driver doesn't need this notification. + * @sw_scan_complete: Notifier function that is called just after a + * software scan finished. Can be NULL, if the driver doesn't need + * this notification. + * The callback can sleep. * * @get_stats: Return low-level statistics. * Returns zero if statistics are available. + * The callback can sleep. * * @get_tkip_seq: If your device implements TKIP encryption in hardware this * callback should be provided to read the TKIP transmit IVs (both IV32 * and IV16) for the given key from hardware. + * The callback must be atomic. * * @set_rts_threshold: Configuration of RTS threshold (if device needs it) + * The callback can sleep. * * @sta_notify: Notifies low level driver about addition, removal or power * state transition of an associated station, AP, IBSS/WDS/mesh peer etc. @@ -1480,30 +1490,36 @@ enum ieee80211_ampdu_mlme_action { * @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max), * bursting) for a hardware TX queue. * Returns a negative error code on failure. + * The callback can sleep. * * @get_tx_stats: Get statistics of the current TX queue status. This is used * to get number of currently queued packets (queue length), maximum queue * size (limit), and total number of packets sent using each TX queue * (count). The 'stats' pointer points to an array that has hw->queues * items. + * The callback must be atomic. * * @get_tsf: Get the current TSF timer value from firmware/hardware. Currently, * this is only used for IBSS mode BSSID merging and debugging. Is not a * required function. + * The callback can sleep. * * @set_tsf: Set the TSF timer to the specified value in the firmware/hardware. * Currently, this is only used for IBSS mode debugging. Is not a * required function. + * The callback can sleep. * * @reset_tsf: Reset the TSF timer and allow firmware/hardware to synchronize * with other STAs in the IBSS. This is only used in IBSS mode. This * function is optional if the firmware/hardware takes full care of * TSF synchronization. + * The callback can sleep. * * @tx_last_beacon: Determine whether the last IBSS beacon was sent by us. * This is needed only for IBSS mode and the result of this function is * used to determine whether to reply to Probe Requests. * Returns non-zero if this device sent the last beacon. + * The callback can sleep. * * @ampdu_action: Perform a certain A-MPDU action * The RA/TID combination determines the destination and TID we want @@ -1512,16 +1528,19 @@ enum ieee80211_ampdu_mlme_action { * is the first frame we expect to perform the action on. Notice * that TX/RX_STOP can pass NULL for this parameter. * Returns a negative error code on failure. + * The callback must be atomic. * * @rfkill_poll: Poll rfkill hardware state. If you need this, you also * need to set wiphy->rfkill_poll to %true before registration, * and need to call wiphy_rfkill_set_hw_state() in the callback. + * The callback can sleep. * * @testmode_cmd: Implement a cfg80211 test mode command. + * The callback can sleep. * * @flush: Flush all pending frames from the hardware queue, making sure * that the hardware queues are empty. If the parameter @drop is set - * to %true, pending frames may be dropped. + * to %true, pending frames may be dropped. The callback can sleep. */ struct ieee80211_ops { int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb); diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index bc7c8f55487a..8757ea73d544 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -14,6 +14,8 @@ static inline int drv_start(struct ieee80211_local *local) { int ret; + might_sleep(); + local->started = true; smp_mb(); ret = local->ops->start(&local->hw); @@ -23,6 +25,8 @@ static inline int drv_start(struct ieee80211_local *local) static inline void drv_stop(struct ieee80211_local *local) { + might_sleep(); + local->ops->stop(&local->hw); trace_drv_stop(local); @@ -38,7 +42,11 @@ static inline void drv_stop(struct ieee80211_local *local) static inline int drv_add_interface(struct ieee80211_local *local, struct ieee80211_vif *vif) { - int ret = local->ops->add_interface(&local->hw, vif); + int ret; + + might_sleep(); + + ret = local->ops->add_interface(&local->hw, vif); trace_drv_add_interface(local, vif_to_sdata(vif), ret); return ret; } @@ -46,13 +54,19 @@ static inline int drv_add_interface(struct ieee80211_local *local, static inline void drv_remove_interface(struct ieee80211_local *local, struct ieee80211_vif *vif) { + might_sleep(); + local->ops->remove_interface(&local->hw, vif); trace_drv_remove_interface(local, vif_to_sdata(vif)); } static inline int drv_config(struct ieee80211_local *local, u32 changed) { - int ret = local->ops->config(&local->hw, changed); + int ret; + + might_sleep(); + + ret = local->ops->config(&local->hw, changed); trace_drv_config(local, changed, ret); return ret; } @@ -62,6 +76,8 @@ static inline void drv_bss_info_changed(struct ieee80211_local *local, struct ieee80211_bss_conf *info, u32 changed) { + might_sleep(); + if (local->ops->bss_info_changed) local->ops->bss_info_changed(&local->hw, &sdata->vif, info, changed); trace_drv_bss_info_changed(local, sdata, info, changed); @@ -111,7 +127,11 @@ static inline int drv_set_key(struct ieee80211_local *local, struct ieee80211_sta *sta, struct ieee80211_key_conf *key) { - int ret = local->ops->set_key(&local->hw, cmd, &sdata->vif, sta, key); + int ret; + + might_sleep(); + + ret = local->ops->set_key(&local->hw, cmd, &sdata->vif, sta, key); trace_drv_set_key(local, cmd, sdata, sta, key, ret); return ret; } @@ -121,6 +141,8 @@ static inline void drv_update_tkip_key(struct ieee80211_local *local, const u8 *address, u32 iv32, u16 *phase1key) { + might_sleep(); + if (local->ops->update_tkip_key) local->ops->update_tkip_key(&local->hw, conf, address, iv32, phase1key); @@ -130,13 +152,19 @@ static inline void drv_update_tkip_key(struct ieee80211_local *local, static inline int drv_hw_scan(struct ieee80211_local *local, struct cfg80211_scan_request *req) { - int ret = local->ops->hw_scan(&local->hw, req); + int ret; + + might_sleep(); + + ret = local->ops->hw_scan(&local->hw, req); trace_drv_hw_scan(local, req, ret); return ret; } static inline void drv_sw_scan_start(struct ieee80211_local *local) { + might_sleep(); + if (local->ops->sw_scan_start) local->ops->sw_scan_start(&local->hw); trace_drv_sw_scan_start(local); @@ -144,6 +172,8 @@ static inline void drv_sw_scan_start(struct ieee80211_local *local) static inline void drv_sw_scan_complete(struct ieee80211_local *local) { + might_sleep(); + if (local->ops->sw_scan_complete) local->ops->sw_scan_complete(&local->hw); trace_drv_sw_scan_complete(local); @@ -154,6 +184,8 @@ static inline int drv_get_stats(struct ieee80211_local *local, { int ret = -EOPNOTSUPP; + might_sleep(); + if (local->ops->get_stats) ret = local->ops->get_stats(&local->hw, stats); trace_drv_get_stats(local, stats, ret); @@ -173,6 +205,9 @@ static inline int drv_set_rts_threshold(struct ieee80211_local *local, u32 value) { int ret = 0; + + might_sleep(); + if (local->ops->set_rts_threshold) ret = local->ops->set_rts_threshold(&local->hw, value); trace_drv_set_rts_threshold(local, value, ret); @@ -193,6 +228,9 @@ static inline int drv_conf_tx(struct ieee80211_local *local, u16 queue, const struct ieee80211_tx_queue_params *params) { int ret = -EOPNOTSUPP; + + might_sleep(); + if (local->ops->conf_tx) ret = local->ops->conf_tx(&local->hw, queue, params); trace_drv_conf_tx(local, queue, params, ret); @@ -210,6 +248,9 @@ static inline int drv_get_tx_stats(struct ieee80211_local *local, static inline u64 drv_get_tsf(struct ieee80211_local *local) { u64 ret = -1ULL; + + might_sleep(); + if (local->ops->get_tsf) ret = local->ops->get_tsf(&local->hw); trace_drv_get_tsf(local, ret); @@ -218,6 +259,8 @@ static inline u64 drv_get_tsf(struct ieee80211_local *local) static inline void drv_set_tsf(struct ieee80211_local *local, u64 tsf) { + might_sleep(); + if (local->ops->set_tsf) local->ops->set_tsf(&local->hw, tsf); trace_drv_set_tsf(local, tsf); @@ -225,6 +268,8 @@ static inline void drv_set_tsf(struct ieee80211_local *local, u64 tsf) static inline void drv_reset_tsf(struct ieee80211_local *local) { + might_sleep(); + if (local->ops->reset_tsf) local->ops->reset_tsf(&local->hw); trace_drv_reset_tsf(local); @@ -233,6 +278,9 @@ static inline void drv_reset_tsf(struct ieee80211_local *local) static inline int drv_tx_last_beacon(struct ieee80211_local *local) { int ret = 1; + + might_sleep(); + if (local->ops->tx_last_beacon) ret = local->ops->tx_last_beacon(&local->hw); trace_drv_tx_last_beacon(local, ret); @@ -256,12 +304,16 @@ static inline int drv_ampdu_action(struct ieee80211_local *local, static inline void drv_rfkill_poll(struct ieee80211_local *local) { + might_sleep(); + if (local->ops->rfkill_poll) local->ops->rfkill_poll(&local->hw); } static inline void drv_flush(struct ieee80211_local *local, bool drop) { + might_sleep(); + trace_drv_flush(local, drop); if (local->ops->flush) local->ops->flush(&local->hw, drop); -- 2.30.2