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/*
* 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/slab.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_interruption_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;
unsigned long flags;
mache_t *pmache;
int found = 0;
/* set name to something sensible */
strcpy (current->comm, "kmcheck");
/* block all signals */
sigfillset(¤t->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 );
}
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