patch-2.4.2 linux/drivers/s390/s390mach.c

• Lines: 535
• Date: Tue Feb 13 14:13:44 2001
• Orig file: v2.4.1/linux/drivers/s390/s390mach.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/drivers/s390/s390mach.c linux/drivers/s390/s390mach.c
@@ -0,0 +1,534 @@
+/*
+ *  arch/s390/kernel/s390mach.c
+ *   S/390 machine check handler,
+ *            currently only channel-reports are supported
+ *
+ *  S390 version
+ *    Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Ingo Adlung (adlung@de.ibm.com)
+ */
+
+#include <linux/config.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/malloc.h>
+#ifdef CONFIG_SMP
+#include <linux/smp.h>
+#endif
+
+#include <asm/irq.h>
+#include <asm/lowcore.h>
+#include <asm/semaphore.h>
+#include <asm/s390io.h>
+#include <asm/s390dyn.h>
+#include <asm/s390mach.h>
+
+#define S390_MACHCHK_DEBUG
+
+static int         s390_machine_check_handler( void * parm );
+static void        s390_enqueue_mchchk( mache_t *mchchk );
+static mache_t    *s390_dequeue_mchchk( void );
+static void        s390_enqueue_free_mchchk( mache_t *mchchk );
+static mache_t    *s390_dequeue_free_mchchk( void );
+static int         s390_collect_crw_info( void );
+
+static mache_t    *mchchk_queue_head = NULL;
+static mache_t    *mchchk_queue_tail = NULL;
+static mache_t    *mchchk_queue_free = NULL;
+static crwe_t     *crw_buffer_anchor = NULL;
+static spinlock_t  mchchk_queue_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t  crw_queue_lock    = SPIN_LOCK_UNLOCKED;
+
+static struct semaphore s_sem;
+
+
+/*
+ * s390_init_machine_check
+ *
+ * initialize machine check handling
+ */
+void s390_init_machine_check( void )
+{
+	crwe_t  *pcrwe;	 /* CRW buffer element pointer */
+	mache_t *pmache;   /* machine check element pointer */
+
+	init_MUTEX_LOCKED( &s_sem );
+
+	pcrwe = kmalloc( MAX_CRW_PENDING * sizeof( crwe_t), GFP_KERNEL);
+
+	if ( pcrwe )
+	{
+		int i;
+
+		crw_buffer_anchor = pcrwe;
+
+		for ( i=0; i < MAX_CRW_PENDING-1; i++)
+		{
+			pcrwe->crwe_next = (crwe_t *)((unsigned long)pcrwe + sizeof(crwe_t));
+   		pcrwe            = pcrwe->crwe_next;
+
+		} /* endfor */	
+
+		pcrwe->crwe_next = NULL;
+
+	}
+	else
+	{
+		panic( "s390_init_machine_check : unable to obtain memory\n");		
+
+	} /* endif */
+
+	pmache = kmalloc( MAX_MACH_PENDING * sizeof( mache_t), GFP_KERNEL);
+
+	if ( pmache )
+	{
+		int i;
+
+		for ( i=0; i < MAX_MACH_PENDING; i++)
+		{
+			s390_enqueue_free_mchchk( pmache );
+		   pmache = (mache_t *)((unsigned long)pmache + sizeof(mache_t));
+
+		} /* endfor */	
+	}
+	else
+	{
+		panic( "s390_init_machine_check : unable to obtain memory\n");		
+
+	} /* endif */
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "init_mach : starting machine check handler\n");
+#endif	
+
+	kernel_thread( s390_machine_check_handler, &s_sem, CLONE_FS | CLONE_FILES);
+
+	ctl_clear_bit( 14, 25 );  // disable damage MCH 	
+#if 1
+  	ctl_set_bit( 14, 28 );		// enable channel report MCH
+#endif
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "init_mach : machine check buffer : head = %08X\n",
+            (unsigned)&mchchk_queue_head);
+	printk( "init_mach : machine check buffer : tail = %08X\n",
+            (unsigned)&mchchk_queue_tail);
+	printk( "init_mach : machine check buffer : free = %08X\n",
+            (unsigned)&mchchk_queue_free);
+	printk( "init_mach : CRW entry buffer anchor = %08X\n",
+            (unsigned)&crw_buffer_anchor);
+	printk( "init_mach : machine check handler ready\n");
+#endif	
+
+	return;
+}
+
+/*
+ * s390_do_machine_check
+ *
+ * mchine check pre-processor, collecting the machine check info,
+ *  queueing it and posting the machine check handler for processing.
+ */
+void s390_do_machine_check( void )
+{
+	int      crw_count;
+	mcic_t   mcic;
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "s390_do_machine_check : starting ...\n");
+#endif
+
+	memcpy( &mcic,
+	        &S390_lowcore.mcck_interuption_code,
+	        sizeof(__u64));
+ 		
+	if ( mcic.mcc.mcd.cp )	// CRW pending ?
+	{
+		crw_count = s390_collect_crw_info();
+
+		if ( crw_count )
+		{
+			up( &s_sem );
+
+		} /* endif */
+
+	} /* endif */
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "s390_do_machine_check : done \n");
+#endif
+
+	return;
+}
+
+/*
+ * s390_machine_check_handler
+ *
+ * machine check handler, dequeueing machine check entries
+ *  and processing them
+ */
+static int s390_machine_check_handler( void *parm)
+{
+	struct semaphore *sem = parm;
+	int               flags;
+	mache_t          *pmache;
+
+	int               found = 0;
+
+        /* set name to something sensible */
+        strcpy (current->comm, "kmcheck");
+
+
+        /* block all signals */
+        sigfillset(&current->blocked);
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "mach_handler : ready\n");
+#endif	
+
+	do {
+
+#ifdef S390_MACHCHK_DEBUG
+		printk( "mach_handler : waiting for wakeup\n");
+#endif	
+
+		down_interruptible( sem );
+
+#ifdef S390_MACHCHK_DEBUG
+		printk( "\nmach_handler : wakeup ... \n");
+#endif	
+		found = 0; /* init ... */
+
+		__save_flags( flags );
+		__cli();
+
+		do {
+
+		pmache = s390_dequeue_mchchk();
+
+		if ( pmache )
+		{
+			found = 1;
+		
+			if ( pmache->mcic.mcc.mcd.cp )
+			{
+				crwe_t *pcrwe_n;
+				crwe_t *pcrwe_h;
+
+				s390_do_crw_pending( pmache->mc.crwe );
+
+				pcrwe_h = pmache->mc.crwe;
+				pcrwe_n = pmache->mc.crwe->crwe_next;
+
+				pmache->mcic.mcc.mcd.cp = 0;
+				pmache->mc.crwe         = NULL;
+
+				spin_lock( &crw_queue_lock);
+
+				while ( pcrwe_h )
+				{
+					pcrwe_h->crwe_next = crw_buffer_anchor;
+					crw_buffer_anchor  = pcrwe_h;
+					pcrwe_h            = pcrwe_n;
+
+					if ( pcrwe_h != NULL )
+						pcrwe_n = pcrwe_h->crwe_next;
+
+				} /* endwhile */
+
+				spin_unlock( &crw_queue_lock);
+
+			} /* endif */
+
+			s390_enqueue_free_mchchk( pmache );
+		}
+		else
+		{
+
+			// unconditional surrender ...
+#ifdef S390_MACHCHK_DEBUG
+			printk( "mach_handler : nothing to do, sleeping\n");
+#endif	
+
+		} /* endif */	
+
+		} while ( pmache );
+
+		__restore_flags( flags );
+
+	} while ( 1 );
+
+	return( 0);
+}
+
+/*
+ * s390_dequeue_mchchk
+ *
+ * Dequeue an entry from the machine check queue
+ *
+ * Note : The queue elements provide for a double linked list.
+ *  We dequeue entries from the tail, and enqueue entries to
+ *  the head.
+ *
+ */
+static mache_t *s390_dequeue_mchchk( void )
+{
+	mache_t *qe;
+
+	spin_lock( &mchchk_queue_lock );
+
+	qe = mchchk_queue_tail;
+
+   if ( qe != NULL )
+   {
+      mchchk_queue_tail = qe->prev;
+
+      if ( mchchk_queue_tail != NULL )
+      {
+			mchchk_queue_tail->next = NULL;
+		}
+		else
+      {
+			mchchk_queue_head = NULL;
+
+      } /* endif */
+
+	} /* endif */
+
+	spin_unlock( &mchchk_queue_lock );
+
+	return qe;
+}
+
+/*
+ * s390_enqueue_mchchk
+ *
+ * Enqueue an entry to the machine check queue.
+ *
+ * Note : The queue elements provide for a double linked list.
+ *  We enqueue entries to the head, and dequeue entries from
+ *  the tail.
+ *
+ */
+static void s390_enqueue_mchchk( mache_t *pmache )
+{
+	spin_lock( &mchchk_queue_lock );
+
+	if ( pmache != NULL )
+	{
+
+		if ( mchchk_queue_head == NULL )  /* first element */
+		{
+  			pmache->next      = NULL;
+  			pmache->prev      = NULL;
+
+			mchchk_queue_head = pmache;
+			mchchk_queue_tail = pmache;
+		}
+		else /* new head */
+		{
+  			pmache->prev            = NULL;
+			pmache->next            = mchchk_queue_head;
+
+			mchchk_queue_head->prev = pmache;
+			mchchk_queue_head       = pmache;
+
+		} /* endif */
+
+	} /* endif */
+
+	spin_unlock( &mchchk_queue_lock );
+
+	return;
+}
+
+
+/*
+ * s390_enqueue_free_mchchk
+ *
+ * Enqueue a free entry to the free queue.
+ *
+ * Note : While the queue elements provide for a double linked list,
+ *  the free queue entries are only concatenated by means of a
+ *  single linked list (forward concatenation).
+ *
+ */
+static void s390_enqueue_free_mchchk( mache_t *pmache )
+{
+	if ( pmache != NULL)
+	{
+		memset( pmache, '\0', sizeof( mache_t ));
+
+		spin_lock( &mchchk_queue_lock );
+		
+		pmache->next = mchchk_queue_free;
+
+		mchchk_queue_free = pmache;
+
+		spin_unlock( &mchchk_queue_lock );
+
+	} /* endif */
+
+	return;
+}
+
+/*
+ * s390_dequeue_free_mchchk
+ *
+ * Dequeue an entry from the free queue.
+ *
+ * Note : While the queue elements provide for a double linked list,
+ *  the free queue entries are only concatenated by means of a
+ *  single linked list (forward concatenation).
+ *
+ */
+static mache_t *s390_dequeue_free_mchchk( void )
+{
+	mache_t *qe;
+
+	spin_lock( &mchchk_queue_lock );
+
+	qe = mchchk_queue_free;
+
+	if ( qe != NULL )
+	{
+		mchchk_queue_free = qe->next;
+
+	} /* endif */
+
+	spin_unlock( &mchchk_queue_lock );
+
+	return qe;
+}
+
+/*
+ * s390_collect_crw_info
+ *
+ * Retrieve CRWs. If a CRW was found a machine check element
+ *  is dequeued from the free chain, filled and enqueued to
+ *  be processed.
+ *
+ * The function returns the number of CRWs found.
+ *
+ * Note : We must always be called disabled ...
+ */
+static int s390_collect_crw_info( void )
+{
+	crw_t    tcrw;     /* temporarily holds a CRW */
+	int      ccode;    /* condition code from stcrw() */
+	crwe_t  *pcrwe;    /* pointer to CRW buffer entry */
+
+	mache_t *pmache = NULL; /* ptr to mchchk entry */
+	int      chain  = 0;    /* indicate chaining */
+	crwe_t  *pccrw  = NULL; /* ptr to current CRW buffer entry */
+	int      count  = 0;    /* CRW count */
+
+#ifdef S390_MACHCHK_DEBUG
+	printk( "crw_info : looking for CRWs ...\n");
+#endif
+
+	do
+	{
+		ccode = stcrw( (__u32 *)&tcrw);
+
+		if ( ccode == 0 )
+		{
+			count++;
+			
+#ifdef S390_MACHCHK_DEBUG
+			printk( "crw_info : CRW reports "
+			        "slct=%d, oflw=%d, chn=%d, "
+			        "rsc=%X, anc=%d, erc=%X, "
+			        "rsid=%X\n",
+			        tcrw.slct,
+			        tcrw.oflw,
+			        tcrw.chn,
+			        tcrw.rsc,
+			        tcrw.anc,
+			        tcrw.erc,
+			        tcrw.rsid );
+#endif
+
+			/*
+			 * Dequeue a CRW entry from the free chain
+			 *  and process it ...
+			 */
+			spin_lock( &crw_queue_lock );
+
+			pcrwe = crw_buffer_anchor;
+
+			if ( pcrwe == NULL )
+			{
+				spin_unlock( &crw_queue_lock );
+				printk( KERN_CRIT"crw_info : "
+				        "no CRW buffer entries available\n");
+				break;
+
+			} /* endif */
+			
+			crw_buffer_anchor = pcrwe->crwe_next;
+			pcrwe->crwe_next  = NULL;
+
+			spin_unlock( &crw_queue_lock );
+
+			memcpy( &(pcrwe->crw), &tcrw, sizeof(crw_t));
+
+			/*
+			 * If it is the first CRW, chain it to the mchchk
+			 *  buffer entry, otherwise to the last CRW entry.
+			 */
+			if ( chain == 0 )
+			{
+				pmache = s390_dequeue_free_mchchk();
+
+				if ( pmache != NULL )
+				{
+					memset( pmache, '\0', sizeof(mache_t));
+
+					pmache->mcic.mcc.mcd.cp = 1;
+					pmache->mc.crwe         = pcrwe;
+					pccrw                   = pcrwe;
+
+				}
+				else
+				{
+					panic( "crw_info : "
+					       "unable to dequeue "
+					       "free mchchk buffer");				
+
+				} /* endif */
+			}
+			else
+			{
+				pccrw->crwe_next = pcrwe;
+				pccrw            = pcrwe;
+
+			} /* endif */	
+
+			if ( pccrw->crw.chn )
+			{
+#ifdef S390_MACHCHK_DEBUG
+				printk( "crw_info : "
+				        "chained CRWs pending ...\n\n");
+#endif
+				chain = 1;
+			}
+			else
+			{
+				chain = 0;
+
+				/*
+				 * We can enqueue the mchchk buffer if
+				 *  there aren't more CRWs chained.
+				 */
+				s390_enqueue_mchchk( pmache);
+
+			} /* endif */
+
+		} /* endif */
+
+	} while ( ccode == 0 );
+
+	return( count );
+}
+