[PATCH] SCSI: aic7xxx replace semaphores
From: Thomas Gleixner
Date: Wed Oct 20 2004 - 16:55:21 EST
Use wait_event, completion instead of semaphores
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
---
2.6.9-bk-041020-thomas/drivers/scsi/aic7xxx/aic7xxx_osm.c | 84
++++++--------
2.6.9-bk-041020-thomas/drivers/scsi/aic7xxx/aic7xxx_osm.h | 8 -
2 files changed, 42 insertions(+), 50 deletions(-)
diff -puN drivers/scsi/aic7xxx/aic7xxx_osm.c~aic7xxx
drivers/scsi/aic7xxx/aic7xxx_osm.c
---
2.6.9-bk-041020/drivers/scsi/aic7xxx/aic7xxx_osm.c~aic7xxx 2004-10-20
16:06:12.000000000 +0200
+++ 2.6.9-bk-041020-thomas/drivers/scsi/aic7xxx/aic7xxx_osm.c 2004-10-20
16:13:23.000000000 +0200
@@ -1873,9 +1873,10 @@ ahc_platform_alloc(struct ahc_softc *ahc
ahc->platform_data->completeq_timer.data = (u_long)ahc;
ahc->platform_data->completeq_timer.function =
(ahc_linux_callback_t *)ahc_linux_thread_run_complete_queue;
- init_MUTEX_LOCKED(&ahc->platform_data->eh_sem);
- init_MUTEX_LOCKED(&ahc->platform_data->dv_sem);
- init_MUTEX_LOCKED(&ahc->platform_data->dv_cmd_sem);
+ init_waitqueue_head(&ahc->platform_data->eh_done);
+ init_waitqueue_head(&ahc->platform_data->dv_done);
+ init_waitqueue_head(&ahc->platform_data->dv_cmd_done);
+ init_completion(&ahc->platform_data->dv_exit);
tasklet_init(&ahc->platform_data->runq_tasklet, ahc_runq_tasklet,
(unsigned long)ahc);
ahc->seltime = (aic7xxx_seltime & 0x3) << 4;
@@ -2156,7 +2157,7 @@ ahc_linux_start_dv(struct ahc_softc *ahc
ahc_linux_freeze_simq(ahc);
/* Wake up the DV kthread */
- up(&ahc->platform_data->dv_sem);
+ wake_up(&ahc->platform_data->dv_done);
}
}
@@ -2169,39 +2170,22 @@ ahc_linux_kill_dv_thread(struct ahc_soft
if (ahc->platform_data->dv_pid != 0) {
ahc->platform_data->flags |= AHC_DV_SHUTDOWN;
ahc_unlock(ahc, &s);
- up(&ahc->platform_data->dv_sem);
+ wake_up(&ahc->platform_data->dv_done);
- /*
- * Use the eh_sem as an indicator that the
- * dv thread is exiting. Note that the dv
- * thread must still return after performing
- * the up on our semaphore before it has
- * completely exited this module. Unfortunately,
- * there seems to be no easy way to wait for the
- * exit of a thread for which you are not the
- * parent (dv threads are parented by init).
- * Cross your fingers...
- */
- down(&ahc->platform_data->eh_sem);
-
- /*
- * Mark the dv thread as already dead. This
- * avoids attempting to kill it a second time.
- * This is necessary because we must kill the
- * DV thread before calling ahc_free() in the
- * module shutdown case to avoid bogus locking
- * in the SCSI mid-layer, but we ahc_free() is
- * called without killing the DV thread in the
- * instance detach case, so ahc_platform_free()
- * calls us again to verify that the DV thread
- * is dead.
- */
- ahc->platform_data->dv_pid = 0;
+ /* Wait until the thread has exited */
+ wait_for_completion(&ahc->platform_data->dv_exit);
} else {
ahc_unlock(ahc, &s);
}
}
+#define AHC_WAIT_FOR_WORK \
+ (ahc->platform_data->flags & (AHC_DV_SHUTDOWN | AHC_DV_ACTIVE))
+#define AHC_WAIT_FOR_SIMQ_EMPTY \
+ (!(ahc->platform_data->flags & AHC_DV_WAIT_SIMQ_EMPTY))
+#define AHC_WAIT_FOR_SIMQ_RELEASE \
+ (!(ahc->platform_data->flags & AHC_DV_WAIT_SIMQ_RELEASE))
+
static int
ahc_linux_dv_thread(void *data)
{
@@ -2235,11 +2219,9 @@ ahc_linux_dv_thread(void *data)
unlock_kernel();
while (1) {
- /*
- * Use down_interruptible() rather than down() to
- * avoid inclusion in the load average.
- */
- down_interruptible(&ahc->platform_data->dv_sem);
+ /* Wait for work */
+ wait_event_interruptible(ahc->platform_data->dv_done,
+ AHC_WAIT_FOR_WORK);
/* Check to see if we've been signaled to exit */
ahc_lock(ahc, &s);
@@ -2262,7 +2244,8 @@ ahc_linux_dv_thread(void *data)
while (LIST_FIRST(&ahc->pending_scbs) != NULL) {
ahc->platform_data->flags |= AHC_DV_WAIT_SIMQ_EMPTY;
ahc_unlock(ahc, &s);
- down_interruptible(&ahc->platform_data->dv_sem);
+ wait_event_interruptible(ahc->platform_data->dv_done,
+ AHC_WAIT_FOR_SIMQ_EMPTY);
ahc_lock(ahc, &s);
}
@@ -2273,7 +2256,8 @@ ahc_linux_dv_thread(void *data)
while (AHC_DV_SIMQ_FROZEN(ahc) == 0) {
ahc->platform_data->flags |= AHC_DV_WAIT_SIMQ_RELEASE;
ahc_unlock(ahc, &s);
- down_interruptible(&ahc->platform_data->dv_sem);
+ wait_event_interruptible(ahc->platform_data->dv_done,
+ AHC_WAIT_FOR_SIMQ_RELEASE);
ahc_lock(ahc, &s);
}
ahc_unlock(ahc, &s);
@@ -2291,7 +2275,9 @@ ahc_linux_dv_thread(void *data)
*/
ahc_linux_release_simq((u_long)ahc);
}
- up(&ahc->platform_data->eh_sem);
+ /* Mark it as gone */
+ ahc->platform_data->dv_pid = 0;
+ complete(&ahc->platform_data->dv_exit);
return (0);
}
@@ -2454,7 +2440,9 @@ ahc_linux_dv_target(struct ahc_softc *ah
#else
spin_unlock_irqrestore(&io_request_lock, s);
#endif
- down_interruptible(&ahc->platform_data->dv_cmd_sem);
+ wait_event_interruptible(ahc->platform_data->dv_cmd_done,
+ !timer_pending(&cmd->eh_timeout));
+
/*
* Wait for the SIMQ to be released so that DV is the
* only reason the queue is frozen.
@@ -2463,7 +2451,8 @@ ahc_linux_dv_target(struct ahc_softc *ah
while (AHC_DV_SIMQ_FROZEN(ahc) == 0) {
ahc->platform_data->flags |= AHC_DV_WAIT_SIMQ_RELEASE;
ahc_unlock(ahc, &s);
- down_interruptible(&ahc->platform_data->dv_sem);
+ wait_event_interruptible(ahc->platform_data->dv_done,
+ AHC_WAIT_FOR_SIMQ_RELEASE);
ahc_lock(ahc, &s);
}
ahc_unlock(ahc, &s);
@@ -3404,7 +3393,7 @@ ahc_linux_dv_complete(struct scsi_cmnd *
#endif
/* Wake up the state machine */
- up(&ahc->platform_data->dv_cmd_sem);
+ wake_up(&ahc->platform_data->dv_cmd_done);
}
static void
@@ -4164,7 +4153,7 @@ ahc_done(struct ahc_softc *ahc, struct s
ahc_set_transaction_status(scb, CAM_CMD_TIMEOUT);
if ((ahc->platform_data->flags & AHC_UP_EH_SEMAPHORE) != 0) {
ahc->platform_data->flags &= ~AHC_UP_EH_SEMAPHORE;
- up(&ahc->platform_data->eh_sem);
+ wake_up(&ahc->platform_data->eh_done);
}
}
@@ -4174,7 +4163,7 @@ ahc_done(struct ahc_softc *ahc, struct s
if ((ahc->platform_data->flags & AHC_DV_WAIT_SIMQ_EMPTY) != 0
&& LIST_FIRST(&ahc->pending_scbs) == NULL) {
ahc->platform_data->flags &= ~AHC_DV_WAIT_SIMQ_EMPTY;
- up(&ahc->platform_data->dv_sem);
+ wake_up(&ahc->platform_data->dv_done);
}
}
@@ -4563,7 +4552,7 @@ ahc_linux_sem_timeout(u_long arg)
ahc_lock(ahc, &s);
if ((ahc->platform_data->flags & AHC_UP_EH_SEMAPHORE) != 0) {
ahc->platform_data->flags &= ~AHC_UP_EH_SEMAPHORE;
- up(&ahc->platform_data->eh_sem);
+ wake_up(&ahc->platform_data->eh_done);
}
ahc_unlock(ahc, &s);
}
@@ -4600,7 +4589,7 @@ ahc_linux_release_simq(u_long arg)
if (AHC_DV_SIMQ_FROZEN(ahc)
&& ((ahc->platform_data->flags & AHC_DV_WAIT_SIMQ_RELEASE) != 0)) {
ahc->platform_data->flags &= ~AHC_DV_WAIT_SIMQ_RELEASE;
- up(&ahc->platform_data->dv_sem);
+ wake_up(&ahc->platform_data->dv_done);
}
ahc_schedule_runq(ahc);
ahc_unlock(ahc, &s);
@@ -4952,7 +4941,8 @@ done:
timer.function = ahc_linux_sem_timeout;
add_timer(&timer);
printf("Recovery code sleeping\n");
- down(&ahc->platform_data->eh_sem);
+ wait_event(ahc->platform_data->eh_done,
+ !(ahc->platform_data->flags & AHC_UP_EH_SEMAPHORE));
printf("Recovery code awake\n");
ret = del_timer_sync(&timer);
if (ret == 0) {
diff -puN drivers/scsi/aic7xxx/aic7xxx_osm.h~aic7xxx
drivers/scsi/aic7xxx/aic7xxx_osm.h
---
2.6.9-bk-041020/drivers/scsi/aic7xxx/aic7xxx_osm.h~aic7xxx 2004-10-20
16:06:23.000000000 +0200
+++ 2.6.9-bk-041020-thomas/drivers/scsi/aic7xxx/aic7xxx_osm.h 2004-10-20
16:08:38.000000000 +0200
@@ -534,11 +534,13 @@ struct ahc_platform_data {
pid_t dv_pid;
struct timer_list completeq_timer;
struct timer_list reset_timer;
- struct semaphore eh_sem;
- struct semaphore dv_sem;
- struct semaphore dv_cmd_sem; /* XXX This needs to be in
+ wait_queue_head_t eh_done;
+ wait_queue_head_t dv_done;
+ wait_queue_head_t dv_cmd_done; /* XXX This needs to be in
* the target struct
*/
+ struct completion dv_exit;
+
struct scsi_device *dv_scsi_dev;
struct Scsi_Host *host; /* pointer to scsi host */
#define AHC_LINUX_NOIRQ ((uint32_t)~0)
_
-
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