diff options
author | Michael Buesch <mb@bu3sch.de> | 2006-06-05 20:24:10 +0200 |
---|---|---|
committer | John W. Linville <linville@tuxdriver.com> | 2006-06-15 15:48:13 -0400 |
commit | 78ff56a06edc3407996173daf63e48f6b90c7062 (patch) | |
tree | 93ddfccd648ee84faeb95bcf8f5183ac91d873f7 /drivers/net/wireless/bcm43xx/bcm43xx.h | |
parent | 74f4903363579d3336c294ebb11f02c8f35845ca (diff) |
[PATCH] bcm43xx: redesign locking
Redesign the bcm43xx locking.
This is pre-work to get a preemptible periodic work handler.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/bcm43xx/bcm43xx.h')
-rw-r--r-- | drivers/net/wireless/bcm43xx/bcm43xx.h | 100 |
1 files changed, 67 insertions, 33 deletions
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx.h b/drivers/net/wireless/bcm43xx/bcm43xx.h index e66fdb1f3cf..d8f917c21ea 100644 --- a/drivers/net/wireless/bcm43xx/bcm43xx.h +++ b/drivers/net/wireless/bcm43xx/bcm43xx.h @@ -636,6 +636,17 @@ struct bcm43xx_key { u8 algorithm; }; +/* Driver initialization status. */ +enum { + BCM43xx_STAT_UNINIT, /* Uninitialized. */ + BCM43xx_STAT_INITIALIZING, /* init_board() in progress. */ + BCM43xx_STAT_INITIALIZED, /* Fully operational. */ + BCM43xx_STAT_SHUTTINGDOWN, /* free_board() in progress. */ + BCM43xx_STAT_RESTARTING, /* controller_restart() called. */ +}; +#define bcm43xx_status(bcm) atomic_read(&(bcm)->init_status) +#define bcm43xx_set_status(bcm, stat) atomic_set(&(bcm)->init_status, (stat)) + struct bcm43xx_private { struct ieee80211_device *ieee; struct ieee80211softmac_device *softmac; @@ -646,18 +657,17 @@ struct bcm43xx_private { void __iomem *mmio_addr; - /* Do not use the lock directly. Use the bcm43xx_lock* helper - * functions, to be MMIO-safe. */ - spinlock_t _lock; + /* Locking, see "theory of locking" text below. */ + spinlock_t irq_lock; + struct mutex mutex; - /* Driver status flags. */ - u32 initialized:1, /* init_board() succeed */ - was_initialized:1, /* for PCI suspend/resume. */ - shutting_down:1, /* free_board() in progress */ + /* Driver initialization status BCM43xx_STAT_*** */ + atomic_t init_status; + + u16 was_initialized:1, /* for PCI suspend/resume. */ __using_pio:1, /* Internal, use bcm43xx_using_pio(). */ bad_frames_preempt:1, /* Use "Bad Frames Preemption" (default off) */ reg124_set_0x4:1, /* Some variable to keep track of IRQ stuff. */ - powersaving:1, /* TRUE if we are in PowerSaving mode. FALSE otherwise. */ short_preamble:1, /* TRUE, if short preamble is enabled. */ firmware_norelease:1; /* Do not release the firmware. Used on suspend. */ @@ -721,7 +731,7 @@ struct bcm43xx_private { struct tasklet_struct isr_tasklet; /* Periodic tasks */ - struct timer_list periodic_tasks; + struct work_struct periodic_work; unsigned int periodic_state; struct work_struct restart_work; @@ -746,21 +756,55 @@ struct bcm43xx_private { #endif }; -/* bcm43xx_(un)lock() protect struct bcm43xx_private. - * Note that _NO_ MMIO writes are allowed. If you want to - * write to the device through MMIO in the critical section, use - * the *_mmio lock functions. - * MMIO read-access is allowed, though. - */ -#define bcm43xx_lock(bcm, flags) spin_lock_irqsave(&(bcm)->_lock, flags) -#define bcm43xx_unlock(bcm, flags) spin_unlock_irqrestore(&(bcm)->_lock, flags) -/* bcm43xx_(un)lock_mmio() protect struct bcm43xx_private and MMIO. - * MMIO write-access to the device is allowed. - * All MMIO writes are flushed on unlock, so it is guaranteed to not - * interfere with other threads writing MMIO registers. + +/* *** THEORY OF LOCKING *** + * + * We have two different locks in the bcm43xx driver. + * => bcm->mutex: General sleeping mutex. Protects struct bcm43xx_private + * and the device registers. + * => bcm->irq_lock: IRQ spinlock. Protects against IRQ handler concurrency. + * + * We have three types of helper function pairs to utilize these locks. + * (Always use the helper functions.) + * 1) bcm43xx_{un}lock_noirq(): + * Takes bcm->mutex. Does _not_ protect against IRQ concurrency, + * so it is almost always unsafe, if device IRQs are enabled. + * So only use this, if device IRQs are masked. + * Locking may sleep. + * You can sleep within the critical section. + * 2) bcm43xx_{un}lock_irqonly(): + * Takes bcm->irq_lock. Does _not_ protect against + * bcm43xx_lock_noirq() critical sections. + * Does only protect against the IRQ handler path and other + * irqonly() critical sections. + * Locking does not sleep. + * You must not sleep within the critical section. + * 3) bcm43xx_{un}lock_irqsafe(): + * This is the cummulative lock and takes both, mutex and irq_lock. + * Protects against noirq() and irqonly() critical sections (and + * the IRQ handler path). + * Locking may sleep. + * You must not sleep within the critical section. */ -#define bcm43xx_lock_mmio(bcm, flags) bcm43xx_lock(bcm, flags) -#define bcm43xx_unlock_mmio(bcm, flags) do { mmiowb(); bcm43xx_unlock(bcm, flags); } while (0) + +/* Lock type 1 */ +#define bcm43xx_lock_noirq(bcm) mutex_lock(&(bcm)->mutex) +#define bcm43xx_unlock_noirq(bcm) mutex_unlock(&(bcm)->mutex) +/* Lock type 2 */ +#define bcm43xx_lock_irqonly(bcm, flags) \ + spin_lock_irqsave(&(bcm)->irq_lock, flags) +#define bcm43xx_unlock_irqonly(bcm, flags) \ + spin_unlock_irqrestore(&(bcm)->irq_lock, flags) +/* Lock type 3 */ +#define bcm43xx_lock_irqsafe(bcm, flags) do { \ + bcm43xx_lock_noirq(bcm); \ + bcm43xx_lock_irqonly(bcm, flags); \ + } while (0) +#define bcm43xx_unlock_irqsafe(bcm, flags) do { \ + bcm43xx_unlock_irqonly(bcm, flags); \ + bcm43xx_unlock_noirq(bcm); \ + } while (0) + static inline struct bcm43xx_private * bcm43xx_priv(struct net_device *dev) @@ -843,16 +887,6 @@ struct bcm43xx_radioinfo * bcm43xx_current_radio(struct bcm43xx_private *bcm) return &(bcm->core_80211_ext[bcm->current_80211_core_idx].radio); } -/* Are we running in init_board() context? */ -static inline -int bcm43xx_is_initializing(struct bcm43xx_private *bcm) -{ - if (bcm->initialized) - return 0; - if (bcm->shutting_down) - return 0; - return 1; -} static inline struct bcm43xx_lopair * bcm43xx_get_lopair(struct bcm43xx_phyinfo *phy, |