Commit e1781ed3 authored by Kalle Valo's avatar Kalle Valo Committed by John W. Linville
Browse files

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: default avatarKalle Valo <kalle.valo@iki.fi>
Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 095d5ef6

include/net/mac80211.h

+31 −12
Original line number Diff line number Diff line
@@ -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);

net/mac80211/driver-ops.h

+56 −4
Original line number Diff line number Diff line
@@ -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);

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