[PATCH 2.6.13-rc6] improve start/stop code for worker thread in cpqfcTS driver, take 3

From: Rolf Eike Beer
Date: Tue Aug 16 2005 - 12:08:29 EST

Improve start/stop code for HBA worker thread. For the moment the return code
of the start/stop functions is ignored, this will change once the init/exit
code is changed to use 2.6 driver model.

Version 2: remove that lock_kernel() stuff missed in the first version
Version 3: use kthread API (pointed out by Christoph Hellwig)

Signed-off-by: Rolf Eike Beer <eike-kernel@xxxxxxxxx>

diff -aup linux-2.6.13-rc6/drivers/scsi/cpqfcTSinit.c linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSinit.c
--- linux-2.6.13-rc6/drivers/scsi/cpqfcTSinit.c 2005-08-16 16:42:14.000000000 +0200
+++ linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSinit.c 2005-08-16 18:59:26.000000000 +0200
@@ -43,6 +43,7 @@
#include <linux/init.h>
#include <linux/ioport.h> // request_region() prototype
#include <linux/completion.h>
+#include <linux/kthread.h>

#include <asm/io.h>
#include <asm/uaccess.h> // ioctl related
@@ -204,32 +205,26 @@ static void Cpqfc_initHBAdata(CPQFCHBA *
}
}

-
-/* (borrowed from linux/drivers/scsi/hosts.c) */
-static void launch_FCworker_thread(struct Scsi_Host *HostAdapter)
+static int launch_FCworker_thread(struct Scsi_Host *HostAdapter)
{
- DECLARE_MUTEX_LOCKED(sem);
-
- CPQFCHBA *cpqfcHBAdata = (CPQFCHBA *)HostAdapter->hostdata;
+ CPQFCHBA *cpqfcHBAdata = (CPQFCHBA *)HostAdapter->hostdata;

- ENTER("launch_FC_worker_thread");
+ ENTER(__function__);

- cpqfcHBAdata->notify_wt = &sem;
+ spin_unlock_irq(HostAdapter->host_lock);

- /* must unlock before kernel_thread(), for it may cause a reschedule. */
- spin_unlock_irq(HostAdapter->host_lock);
- kernel_thread((int (*)(void *))cpqfcTSWorkerThread,
- (void *) HostAdapter, 0);
- /*
- * Now wait for the kernel error thread to initialize itself
-
- */
- down (&sem);
- spin_lock_irq(HostAdapter->host_lock);
- cpqfcHBAdata->notify_wt = NULL;
+ cpqfcHBAdata->worker_thread = kthread_run(cpqfcTSWorkerThread,
+ HostAdapter,
+ "cpqfcTS_wt_%d", HostAdapter->host_no);
+ if (IS_ERR(cpqfcHBAdata->worker_thread)) {
+ printk(KERN_ERR DEV_NAME " can't start worker thread\n");
+ return PTR_ERR(cpqfcHBAdata->worker_thread);
+ }

- LEAVE("launch_FC_worker_thread");
+ spin_lock_irq(HostAdapter->host_lock);

+ LEAVE(__function__);
+ return 0;
}


@@ -317,9 +312,7 @@ int cpqfcTS_detect(Scsi_Host_Template *S
// each HBA on the PCI bus(ses)).
cpqfcHBAdata = (CPQFCHBA *)HostAdapter->hostdata;

- // make certain our data struct is clear
- memset( cpqfcHBAdata, 0, sizeof( CPQFCHBA ) );
-
+ memset(cpqfcHBAdata, 0, sizeof(*cpqfcHBAdata));

// initialize our HBA info
cpqfcHBAdata->HBAnum = NumberOfAdapters;
@@ -731,18 +724,7 @@ int cpqfcTS_release(struct Scsi_Host *Ho
DEBUG_PCI( printk(" disable hardware, destroy queues, free mem\n"));
cpqfcHBAdata->fcChip.ResetTachyon( cpqfcHBAdata, CLEAR_FCPORTS);

- // kill kernel thread
- if( cpqfcHBAdata->worker_thread ) // (only if exists)
- {
- DECLARE_MUTEX_LOCKED(sem); // synchronize thread kill
-
- cpqfcHBAdata->notify_wt = &sem;
- DEBUG_PCI( printk(" killing kernel thread\n"));
- send_sig( SIGKILL, cpqfcHBAdata->worker_thread, 1);
- down( &sem);
- cpqfcHBAdata->notify_wt = NULL;
-
- }
+ kthread_stop(cpqfcHBAdata->worker_thread);

cpqfc_free_private_data_pool(cpqfcHBAdata);
// free Linux resources
diff -aup linux-2.6.13-rc6/drivers/scsi/cpqfcTSstructs.h linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSstructs.h
--- linux-2.6.13-rc6/drivers/scsi/cpqfcTSstructs.h 2005-08-16 16:42:14.000000000 +0200
+++ linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSstructs.h 2005-08-16 19:01:42.000000000 +0200
@@ -829,7 +829,7 @@ int CpqTsReadWriteWWN(void*, int ReadWri
int CpqTsReadWriteNVRAM(void*, void* data, int ReadWrite);

void cpqfcTS_WorkTask( struct Scsi_Host *HostAdapter);
-void cpqfcTSWorkerThread( void *host);
+extern int cpqfcTSWorkerThread(void *host);

int cpqfcTS_GetNVRAM_data( UCHAR *wwnbuf, UCHAR *buf );
ULONG cpqfcTS_ReadNVRAM( void* GPIOin, void* GPIOout , USHORT count,
diff -aup linux-2.6.13-rc6/drivers/scsi/cpqfcTSworker.c linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSworker.c
--- linux-2.6.13-rc6/drivers/scsi/cpqfcTSworker.c 2005-08-16 16:42:14.000000000 +0200
+++ linux-2.6.13-rc6-eike/drivers/scsi/cpqfcTSworker.c 2005-08-16 19:05:42.000000000 +0200
@@ -31,8 +31,7 @@
#include <linux/delay.h>
#include <linux/smp_lock.h>
#include <linux/pci.h>
-
-#define SHUTDOWN_SIGS (sigmask(SIGKILL)|sigmask(SIGINT)|sigmask(SIGTERM))
+#include <linux/kthread.h>

#include <asm/system.h>
#include <asm/irq.h>
@@ -145,9 +144,8 @@ static void IssueReportLunsCommand(
CPQFCHBA* cpqfcHBAdata,
TachFCHDR_GCMND* fchs);

-// (see scsi_error.c comments on kernel task creation)
-
-void cpqfcTSWorkerThread( void *host)
+int
+cpqfcTSWorkerThread(void *host)
{
struct Scsi_Host *HostAdapter = (struct Scsi_Host*)host;
CPQFCHBA *cpqfcHBAdata = (CPQFCHBA *)HostAdapter->hostdata;
@@ -159,24 +157,11 @@ void cpqfcTSWorkerThread( void *host)
DECLARE_MUTEX_LOCKED(TachFrozen);
DECLARE_MUTEX_LOCKED(BoardLock);

- ENTER("WorkerThread");
-
- lock_kernel();
- daemonize("cpqfcTS_wt_%d", HostAdapter->host_no);
- siginitsetinv(&current->blocked, SHUTDOWN_SIGS);
-
+ ENTER(__function__);

cpqfcHBAdata->fcQueReady = &fcQueReady; // primary wait point
cpqfcHBAdata->TYOBcomplete = &fcTYOBcomplete;
cpqfcHBAdata->TachFrozen = &TachFrozen;
-
-
- cpqfcHBAdata->worker_thread = current;
-
- unlock_kernel();
-
- if( cpqfcHBAdata->notify_wt != NULL )
- up( cpqfcHBAdata->notify_wt); // OK to continue

while(1)
{
@@ -184,9 +169,11 @@ void cpqfcTSWorkerThread( void *host)

down_interruptible( &fcQueReady); // wait for something to do

- if (signal_pending(current) )
- break;
-
+ if (signal_pending(current))
+ flush_signals(current);
+ if (kthread_should_stop())
+ return 0;
+
PCI_TRACE( 0x90)
// first, take the IO lock so the SCSI upper layers can't call
// into our _quecommand function (this also disables INTs)
@@ -225,15 +212,9 @@ void cpqfcTSWorkerThread( void *host)
// Now, complete any Cmnd we Q'd up while BoardLock was held

CompleteBoardLockCmnd( cpqfcHBAdata);
-
-
}
- // hopefully, the signal was for our module exit...
- if( cpqfcHBAdata->notify_wt != NULL )
- up( cpqfcHBAdata->notify_wt); // yep, we're outta here
}

-
// Freeze Tachyon routine.
// If Tachyon is already frozen, return FALSE
// If Tachyon is not frozen, call freeze function, return TRUE
-
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