linux/drivers/net/wireless/iwlwifi/iwl-notif-wait.h
Johannes Berg db662d4786 iwlwifi: extend notification wait
Sometimes, for example when we ask the uCode
for calibration, we wait for the "complete"
response while we also need the results that
are sent in other, interim, notifications.

Currently we handle this by installing an RX
handler globally, but that isn't needed as
this is the only time we want to use these
notifications.

So in order to be able to simplify at least
future code that does the same, extend the
notification wait framework to allow you to
wait for multiple commands and decide based
on the command whether the wait finished.

While at it, also fix a race that can then
become relevant -- if the wait function has
returned true once it shouldn't be called
again, today this can happen due to races
between the triggering and the wakeup.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-09 16:37:15 -04:00

139 lines
5.2 KiB
C

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#ifndef __iwl_notif_wait_h__
#define __iwl_notif_wait_h__
#include <linux/wait.h>
#include "iwl-trans.h"
struct iwl_notif_wait_data {
struct list_head notif_waits;
spinlock_t notif_wait_lock;
wait_queue_head_t notif_waitq;
};
#define MAX_NOTIF_CMDS 5
/**
* struct iwl_notification_wait - notification wait entry
* @list: list head for global list
* @fn: Function called with the notification. If the function
* returns true, the wait is over, if it returns false then
* the waiter stays blocked. If no function is given, any
* of the listed commands will unblock the waiter.
* @cmds: command IDs
* @n_cmds: number of command IDs
* @triggered: waiter should be woken up
* @aborted: wait was aborted
*
* This structure is not used directly, to wait for a
* notification declare it on the stack, and call
* iwlagn_init_notification_wait() with appropriate
* parameters. Then do whatever will cause the ucode
* to notify the driver, and to wait for that then
* call iwlagn_wait_notification().
*
* Each notification is one-shot. If at some point we
* need to support multi-shot notifications (which
* can't be allocated on the stack) we need to modify
* the code for them.
*/
struct iwl_notification_wait {
struct list_head list;
bool (*fn)(struct iwl_notif_wait_data *notif_data,
struct iwl_rx_packet *pkt, void *data);
void *fn_data;
u8 cmds[MAX_NOTIF_CMDS];
u8 n_cmds;
bool triggered, aborted;
};
/* caller functions */
void iwl_notification_wait_init(struct iwl_notif_wait_data *notif_data);
void iwl_notification_wait_notify(struct iwl_notif_wait_data *notif_data,
struct iwl_rx_packet *pkt);
void iwl_abort_notification_waits(struct iwl_notif_wait_data *notif_data);
/* user functions */
void __acquires(wait_entry)
iwl_init_notification_wait(struct iwl_notif_wait_data *notif_data,
struct iwl_notification_wait *wait_entry,
const u8 *cmds, int n_cmds,
bool (*fn)(struct iwl_notif_wait_data *notif_data,
struct iwl_rx_packet *pkt, void *data),
void *fn_data);
int __must_check __releases(wait_entry)
iwl_wait_notification(struct iwl_notif_wait_data *notif_data,
struct iwl_notification_wait *wait_entry,
unsigned long timeout);
void __releases(wait_entry)
iwl_remove_notification(struct iwl_notif_wait_data *notif_data,
struct iwl_notification_wait *wait_entry);
#endif /* __iwl_notif_wait_h__ */