s390io.c

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		debug_text_event(cio_debug_trace_id, 2, dbf_txt);
	}

	return( ret );
}


/*
 * Disable IRQ by modifying the subchannel
 */
static int disable_subchannel( unsigned int irq)
{
	int  cc;          /* condition code */
	int  ret = 0;     /* function return value */
	int  retry = 5;
	char dbf_txt[15];

	SANITY_CHECK(irq);
	
	if ( ioinfo[irq]->ui.flags.busy )
	{
		/*
		 * the disable function must not be called while there are
		 *  requests pending for completion !
		 */
		ret = -EBUSY;
	}
	else
	{
		if (cio_debug_initialized) {
			sprintf(dbf_txt, "dissch%x", irq);
			debug_text_event(cio_debug_trace_id, 2, dbf_txt);
		}
		
		/*
		 * If device isn't operational we have to perform delayed
		 *  disabling when the next interrupt occurs - unless the
		 *  irq is re-requested prior to the interrupt to occur.
		 */
		cc = stsch(irq, &(ioinfo[irq]->schib) );

		if ( cc == 3 )
		{
			ioinfo[irq]->ui.flags.oper      = 0;
			ioinfo[irq]->ui.flags.d_disable = 1;

			ret = 0;
		}
		else // cc == 0
		{
			ioinfo[irq]->schib.pmcw.ena = 0;

			do
			{
				cc = msch( irq, &(ioinfo[irq]->schib) );

				switch (cc) {
				case 0: /* ok */
					retry = 0;
					ret = 0;   
					break;

				case 1: /* status pending */
					ioinfo[irq]->ui.flags.s_pend = 1;
					s390_process_IRQ( irq );
					ioinfo[irq]->ui.flags.s_pend = 0;

					ret = -EIO; /* might be overwritten  */
					            /* ... on re-driving the */
					            /* ... msch() call       */
					retry--;
					break;

				case 2: /* busy; this should not happen! */
					printk( KERN_CRIT"disable_subchannel(%04X) "
					        "- unexpected busy condition for "
						"device %04X received !\n",
					        irq,
					        ioinfo[irq]->devstat.devno);
					if (cio_debug_initialized)
						debug_sprintf_event(cio_debug_msg_id, 0, 
								    "disable_subchannel(%04X) - unexpected busy condition for device %04X received !\n",
								    irq, ioinfo[irq]->devstat.devno);
					retry = 0;
					ret = -EBUSY;
					break;

				case 3: /* not oper */
					/*
					 * should hardly occur ?!
					 */
					ioinfo[irq]->ui.flags.oper      = 0;
					ioinfo[irq]->ui.flags.d_disable = 1;
					retry = 0;

					ret = 0; /* if the device has gone we */
					         /* ... don't need to disable */
					         /* ... it anymore !          */
					break;

				} /* endswitch */

			} while ( retry );

		} /* endif */

	} /* endif */

	if (cio_debug_initialized) {
		sprintf(dbf_txt, "ret:%d",ret);
		debug_text_event(cio_debug_trace_id, 2, dbf_txt);
	}

	return( ret);
}


void s390_init_IRQ( void )
{
	unsigned long flags;     /* PSW flags */
	long          cr6 __attribute__ ((aligned (8)));

	asm volatile ("STCK %0" : "=m" (irq_IPL_TOD));

	p_init_schib = alloc_bootmem_low( sizeof(schib_t));
	p_init_irb   = alloc_bootmem_low( sizeof(irb_t));
	
	
	/*
	 * As we don't know about the calling environment
	 *  we assure running disabled. Before leaving the
	 *  function we resestablish the old environment.
	 *
	 * Note : as we don't need a system wide lock, therefore
	 *        we shouldn't use cli(), but __cli() as this
	 *        affects the current CPU only.
	 */
	__save_flags(flags);
	__cli();

	/*
	 * disable all interrupts
	 */
	cr6 = 0;
	__ctl_load( cr6, 6, 6);

	s390_process_subchannels();

	if (cio_count_irqs) {
		int i;
		for (i=0; i<NR_CPUS; i++) 
			s390_irq_count[i]=0;
	}

	/*
	 * enable default I/O-interrupt sublass 3
	 */
	cr6 = 0x10000000;
	__ctl_load( cr6, 6, 6);

	s390_device_recognition_all();

	init_IRQ_complete = 1;

	__restore_flags(flags);

	return;
}


/*
 * dummy handler, used during init_IRQ() processing for compatibility only
 */
void  init_IRQ_handler( int irq, void *dev_id, struct pt_regs *regs)
{
   /* this is a dummy handler only ... */
}


int s390_start_IO( int            irq,      /* IRQ */
                   ccw1_t        *cpa,      /* logical channel prog addr */
                   unsigned long  user_intparm,  /* interruption parameter */
                   __u8           lpm,      /* logical path mask */
                   unsigned long  flag)     /* flags */
{
	int            ccode;
	int            ret = 0;
	char buffer[80];
	char dbf_txt[15];

	SANITY_CHECK(irq);

	/*
	 * The flag usage is mutal exclusive ...
	 */
	if (    (flag & DOIO_EARLY_NOTIFICATION)
	     && (flag & DOIO_REPORT_ALL     ) )
	{
		return( -EINVAL );

	} /* endif */

	if (cio_debug_initialized) {
		sprintf(dbf_txt, "stIO%x", irq);
		debug_text_event(cio_debug_trace_id, 4, dbf_txt);
	}

	/*
	 * setup ORB
	 */
  	ioinfo[irq]->orb.intparm = (__u32)(long)&ioinfo[irq]->u_intparm;
	ioinfo[irq]->orb.fmt     = 1;

	ioinfo[irq]->orb.pfch = !(flag & DOIO_DENY_PREFETCH);
	ioinfo[irq]->orb.spnd =  (flag & DOIO_ALLOW_SUSPEND ? TRUE : FALSE);
	ioinfo[irq]->orb.ssic =  (    (flag & DOIO_ALLOW_SUSPEND )
	                           && (flag & DOIO_SUPPRESS_INTER) );

	if ( flag & DOIO_VALID_LPM )
	{
		ioinfo[irq]->orb.lpm = lpm;
	}
	else
	{
		ioinfo[irq]->orb.lpm = ioinfo[irq]->opm;

	} /* endif */

#ifdef CONFIG_ARCH_S390X
	/* 
	 * for 64 bit we always support 64 bit IDAWs with 4k page size only
	 */
	ioinfo[irq]->orb.c64 = 1;
	ioinfo[irq]->orb.i2k = 0;
#endif

	ioinfo[irq]->orb.cpa = (__u32)virt_to_phys( cpa);

	/*
	 * If sync processing was requested we lock the sync ISC, modify the
	 *  device to present interrupts for this ISC only and switch the
	 *  CPU to handle this ISC + the console ISC exclusively.
	 */
	if ( flag & DOIO_WAIT_FOR_INTERRUPT )
	{
		ret = enable_cpu_sync_isc( irq);
	
		if ( ret )
		{
			return( ret);
		}

	} /* endif */

	if ( flag & DOIO_DONT_CALL_INTHDLR )
	{
		ioinfo[irq]->ui.flags.repnone = 1;

	} /* endif */

	/*
	 * Issue "Start subchannel" and process condition code
	 */
	ccode = ssch( irq, &(ioinfo[irq]->orb) );

	if (cio_debug_initialized) {
		sprintf(dbf_txt, "ccode:%d", ccode);
		debug_text_event(cio_debug_trace_id, 4, dbf_txt);
	}

	switch ( ccode ) {
	case 0:

		if ( !ioinfo[irq]->ui.flags.w4sense )
		{
			/*
			 * init the device driver specific devstat irb area
			 *
			 * Note : don磘 clear saved irb info in case of sense !
			 */
			memset( &((devstat_t *)ioinfo[irq]->irq_desc.dev_id)->ii.irb,
				'\0', sizeof( irb_t) );
		} /* endif */

		memset( &ioinfo[irq]->devstat.ii.irb,
		        '\0',
		        sizeof( irb_t) );

		/*
		 * initialize device status information
		 */
		ioinfo[irq]->ui.flags.busy   = 1;
		ioinfo[irq]->ui.flags.doio   = 1;

		ioinfo[irq]->u_intparm       = user_intparm;
		ioinfo[irq]->devstat.cstat   = 0;
		ioinfo[irq]->devstat.dstat   = 0;
		ioinfo[irq]->devstat.lpum    = 0;
		ioinfo[irq]->devstat.flag    = DEVSTAT_START_FUNCTION;
		ioinfo[irq]->devstat.scnt    = 0;

		ioinfo[irq]->ui.flags.fast   = 0;
		ioinfo[irq]->ui.flags.repall = 0;

		/*
		 * Check for either early (FAST) notification requests
		 *  or if we are to return all interrupt info.
		 * Default is to call IRQ handler at secondary status only
		 */
		if ( flag & DOIO_EARLY_NOTIFICATION )
		{
			ioinfo[irq]->ui.flags.fast = 1;
		}
		else if ( flag & DOIO_REPORT_ALL )
		{
			ioinfo[irq]->ui.flags.repall = 1;

		} /* endif */

		ioinfo[irq]->ulpm = ioinfo[irq]->orb.lpm;

		/*
		 * If synchronous I/O processing is requested, we have
		 *  to wait for the corresponding interrupt to occur by
		 *  polling the interrupt condition. However, as multiple
		 *  interrupts may be outstanding, we must not just wait
		 *  for the first interrupt, but must poll until ours
		 *  pops up.
		 */
		if ( flag & DOIO_WAIT_FOR_INTERRUPT )
		{
			psw_t            io_new_psw;
			int              ccode;
			uint64_t         time_start;    	
			uint64_t         time_curr;    	

			int              ready    = 0;
			int              io_sub   = -1;
			struct _lowcore *lc       = NULL;
			int              do_retry = 1;

			/*
			 * We shouldn't perform a TPI loop, waiting for an
			 *  interrupt to occur, but should load a WAIT PSW
			 *  instead. Otherwise we may keep the channel subsystem
			 *  busy, not able to present the interrupt. When our
			 *  sync. interrupt arrived we reset the I/O old PSW to
			 *  its original value.
			 */
			memcpy( &io_new_psw, &lc->io_new_psw, sizeof(psw_t));

			ccode = iac();

			switch (ccode) {
			case 0:  		// primary-space
				io_sync_wait.mask =   _IO_PSW_MASK
				                    | _PSW_PRIM_SPACE_MODE
				                    | _PSW_IO_WAIT;
				break;
			case 1:			// secondary-space
				io_sync_wait.mask =   _IO_PSW_MASK
				                    | _PSW_SEC_SPACE_MODE
				                    | _PSW_IO_WAIT;
				break;
			case 2:			// access-register
				io_sync_wait.mask =   _IO_PSW_MASK
				                    | _PSW_ACC_REG_MODE
				                    | _PSW_IO_WAIT;
				break;
			case 3:			// home-space	
				io_sync_wait.mask =   _IO_PSW_MASK
				                    | _PSW_HOME_SPACE_MODE
				                    | _PSW_IO_WAIT;
				break;
			default:
				panic( "start_IO() : unexpected "
				       "address-space-control %d\n",
				       ccode);
				break;
			} /* endswitch */

			io_sync_wait.addr = FIX_PSW(&&io_wakeup);

			/*
			 * Martin didn't like modifying the new PSW, now we take
			 *  a fast exit in do_IRQ() instead
			 */
			*(__u32 *)__LC_SYNC_IO_WORD  = 1;

			asm volatile ("STCK %0" : "=m" (time_start));

			time_start = time_start >> 32;

			do
			{
				if ( flag & DOIO_TIMEOUT )
				{
					tpi_info_t tpi_info={0,};

					do
					{
						if ( tpi(&tpi_info) == 1 )
						{
							io_sub = tpi_info.irq;
							break;
						}
						else
						{
							udelay(100); /* usecs */
							asm volatile ("STCK %0" : "=m" (time_curr));

							if ( ((time_curr >> 32) - time_start ) >= 3 )
								do_retry = 0;          							

						} /* endif */
				
					} while ( do_retry );
				}
				else
				{
					__load_psw( io_sync_wait );

io_wakeup:
					io_sub  = (__u32)*(__u16 *)__LC_SUBCHANNEL_NR;

				} /* endif */

 				if ( do_retry )
					ready = s390_process_IRQ( io_sub );

				/*
				 * surrender when retry count's exceeded ...
				 */
			} while ( !(     ( io_sub == irq )
			              && ( ready  == 1   ))
			            && do_retry             );

			*(__u32 *)__LC_SYNC_IO_WORD = 0;

			if ( !do_retry )
				ret = -ETIMEDOUT;

		} /* endif */

		break;

	case 1 :            /* status pending */

		ioinfo[irq]->devstat.flag =   DEVSTAT_START_FUNCTION
		                            | DEVSTAT_STATUS_PENDING;

		/*
		 * initialize the device driver specific devstat irb area
		 */
		memset( &((devstat_t *) ioinfo[irq]->irq_desc.dev_id)->ii.irb,
		        '\0', sizeof( irb_t) );

		/*
		 * Let the common interrupt handler process the pending status.
		 *  However, we must avoid calling the user action handler, as
		 *  it won't be prepared to handle a pending status during
		 *  do_IO() processing inline. This also implies that process_IRQ
		 *  must terminate synchronously - especially if device sensing
		 *  is required.
		 */
		ioinfo[irq]->ui.flags.s_pend   = 1;
		ioinfo[irq]->ui.flags.busy     = 1;
		ioinfo[irq]->ui.flags.doio     = 1;

		s390_process_IRQ( irq );

		ioinfo[irq]->ui.flags.s_pend   = 0;
		ioinfo[irq]->ui.flags.busy     = 0;
		ioinfo[irq]->ui.flags.doio     = 0;

		ioinfo[irq]->ui.flags.repall   = 0;
		ioinfo[irq]->ui.flags.w4final  = 0;

		ioinfo[irq]->devstat.flag     |= DEVSTAT_FINAL_STATUS;

		/*
		 * In multipath mode a condition code 3 implies the last path
		 *  has gone, except we have previously restricted the I/O to
		 *  a particular path. A condition code 1 (0 won't occur)
		 *  results in return code EIO as well as 3 with another path
		 *  than the one used (i.e. path available mask is non-zero).
		 */
		if ( ioinfo[irq]->devstat.ii.irb.scsw.cc == 3 )
		{
			if ( flag & DOIO_VALID_LPM )
			{
				ioinfo[irq]->opm &= ~(ioinfo[irq]->devstat.ii.irb.esw.esw1.lpum);
			}
			else
			{
				ioinfo[irq]->opm = 0;

			} /* endif */
	
			if ( ioinfo[irq]->opm == 0 ) 	
			{
				ret                         = -ENODEV;
				ioinfo[irq]->ui.flags.oper  = 0;
			}
			else
			{
				ret = -EIO;

			} /* endif */

			ioinfo[irq]->devstat.flag  |= DEVSTAT_NOT_OPER;

#ifdef CONFIG_DEBUG_IO
			{

			stsch(irq, &(ioinfo[irq]->schib) );

			sprintf( buffer, "s390_start_IO(%04X) - irb for "
			         "device %04X, after status pending\n",
			         irq,
			         ioinfo[irq]->devstat.devno );

			s390_displayhex( buffer,
			                 &(ioinfo[irq]->devstat.ii.irb) ,
			                 sizeof(irb_t));

			sprintf( buffer, "s390_start_IO(%04X) - schib for "
			         "device %04X, after status pending\n",
			         irq,
			         ioinfo[irq]->devstat.devno );

			s390_displayhex( buffer,
			                 &(ioinfo[irq]->schib) ,
			                 sizeof(schib_t));


			if (ioinfo[irq]->devstat.flag & DEVSTAT_FLAG_SENSE_AVAIL)
			{
				sprintf( buffer, "s390_start_IO(%04X) - sense "
				         "data for "
				         "device %04X, after status pending\n",
				         irq,