qdio.c

linux-2.6.15.6

{
	int no_used;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif

	no_used=atomic_read(&q->number_of_buffers_used);

#ifdef CONFIG_QDIO_DEBUG
	if (no_used) {
		sprintf(dbf_text,"oqisnt%02x",no_used);
		QDIO_DBF_TEXT4(0,trace,dbf_text);
	} else {
		QDIO_DBF_TEXT4(0,trace,"oqisdone");
	}
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
#endif /* CONFIG_QDIO_DEBUG */
	return (no_used==0);
}

static inline int
qdio_has_outbound_q_moved(struct qdio_q *q)
{
	int i;

	i=qdio_get_outbound_buffer_frontier(q);

	if ( (i!=GET_SAVED_FRONTIER(q)) ||
	     (q->error_status_flags&QDIO_STATUS_LOOK_FOR_ERROR) ) {
		SAVE_FRONTIER(q,i);
		QDIO_DBF_TEXT4(0,trace,"oqhasmvd");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		return 1;
	} else {
		QDIO_DBF_TEXT4(0,trace,"oqhsntmv");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		return 0;
	}
}

static inline void
qdio_kick_outbound_q(struct qdio_q *q)
{
	int result;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];

	QDIO_DBF_TEXT4(0,trace,"kickoutq");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
#endif /* CONFIG_QDIO_DEBUG */

	if (!q->siga_out)
		return;

	/* here's the story with cc=2 and busy bit set (thanks, Rick):
	 * VM's CP could present us cc=2 and busy bit set on SIGA-write
	 * during reconfiguration of their Guest LAN (only in HIPERS mode,
	 * QDIO mode is asynchronous -- cc=2 and busy bit there will take
	 * the queues down immediately; and not being under VM we have a
	 * problem on cc=2 and busy bit set right away).
	 *
	 * Therefore qdio_siga_output will try for a short time constantly,
	 * if such a condition occurs. If it doesn't change, it will
	 * increase the busy_siga_counter and save the timestamp, and
	 * schedule the queue for later processing (via mark_q, using the
	 * queue tasklet). __qdio_outbound_processing will check out the
	 * counter. If non-zero, it will call qdio_kick_outbound_q as often
	 * as the value of the counter. This will attempt further SIGA
	 * instructions. For each successful SIGA, the counter is
	 * decreased, for failing SIGAs the counter remains the same, after
	 * all.
	 * After some time of no movement, qdio_kick_outbound_q will
	 * finally fail and reflect corresponding error codes to call
	 * the upper layer module and have it take the queues down.
	 *
	 * Note that this is a change from the original HiperSockets design
	 * (saying cc=2 and busy bit means take the queues down), but in
	 * these days Guest LAN didn't exist... excessive cc=2 with busy bit
	 * conditions will still take the queues down, but the threshold is
	 * higher due to the Guest LAN environment.
	 */


	result=qdio_siga_output(q);

		switch (result) {
		case 0:
			/* went smooth this time, reset timestamp */
#ifdef CONFIG_QDIO_DEBUG
			QDIO_DBF_TEXT3(0,trace,"cc2reslv");
			sprintf(dbf_text,"%4x%2x%2x",q->irq,q->q_no,
				atomic_read(&q->busy_siga_counter));
			QDIO_DBF_TEXT3(0,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */
			q->timing.busy_start=0;
			break;
		case (2|QDIO_SIGA_ERROR_B_BIT_SET):
			/* cc=2 and busy bit: */
			atomic_inc(&q->busy_siga_counter);

			/* if the last siga was successful, save
			 * timestamp here */
			if (!q->timing.busy_start)
				q->timing.busy_start=NOW;

			/* if we're in time, don't touch error_status_flags
			 * and siga_error */
			if (NOW-q->timing.busy_start<QDIO_BUSY_BIT_GIVE_UP) {
				qdio_mark_q(q);
				break;
			}
			QDIO_DBF_TEXT2(0,trace,"cc2REPRT");
#ifdef CONFIG_QDIO_DEBUG
			sprintf(dbf_text,"%4x%2x%2x",q->irq,q->q_no,
				atomic_read(&q->busy_siga_counter));
			QDIO_DBF_TEXT3(0,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */
			/* else fallthrough and report error */
		default:
			/* for plain cc=1, 2 or 3: */
			if (q->siga_error)
				q->error_status_flags|=
					QDIO_STATUS_MORE_THAN_ONE_SIGA_ERROR;
			q->error_status_flags|=
				QDIO_STATUS_LOOK_FOR_ERROR;
			q->siga_error=result;
		}
}

static inline void
qdio_kick_outbound_handler(struct qdio_q *q)
{
	int start, end, real_end, count;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif

	start = q->first_element_to_kick;
	/* last_move_ftc was just updated */
	real_end = GET_SAVED_FRONTIER(q);
	end = (real_end+QDIO_MAX_BUFFERS_PER_Q-1)&
		(QDIO_MAX_BUFFERS_PER_Q-1);
	count = (end+QDIO_MAX_BUFFERS_PER_Q+1-start)&
		(QDIO_MAX_BUFFERS_PER_Q-1);

#ifdef CONFIG_QDIO_DEBUG
	QDIO_DBF_TEXT4(0,trace,"kickouth");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	sprintf(dbf_text,"s=%2xc=%2x",start,count);
	QDIO_DBF_TEXT4(0,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */

	if (q->state==QDIO_IRQ_STATE_ACTIVE)
		q->handler(q->cdev,QDIO_STATUS_OUTBOUND_INT|
			   q->error_status_flags,
			   q->qdio_error,q->siga_error,q->q_no,start,count,
			   q->int_parm);

	/* for the next time: */
	q->first_element_to_kick=real_end;
	q->qdio_error=0;
	q->siga_error=0;
	q->error_status_flags=0;
}

static inline void
__qdio_outbound_processing(struct qdio_q *q)
{
	int siga_attempts;

	QDIO_DBF_TEXT4(0,trace,"qoutproc");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	if (unlikely(qdio_reserve_q(q))) {
		qdio_release_q(q);
#ifdef QDIO_PERFORMANCE_STATS
		o_p_c++;
#endif /* QDIO_PERFORMANCE_STATS */
		/* as we're sissies, we'll check next time */
		if (likely(!atomic_read(&q->is_in_shutdown))) {
			qdio_mark_q(q);
			QDIO_DBF_TEXT4(0,trace,"busy,agn");
		}
		return;
	}
#ifdef QDIO_PERFORMANCE_STATS
	o_p_nc++;
	perf_stats.tl_runs++;
#endif /* QDIO_PERFORMANCE_STATS */

	/* see comment in qdio_kick_outbound_q */
	siga_attempts=atomic_read(&q->busy_siga_counter);
	while (siga_attempts) {
		atomic_dec(&q->busy_siga_counter);
		qdio_kick_outbound_q(q);
		siga_attempts--;
	}

	if (qdio_has_outbound_q_moved(q))
		qdio_kick_outbound_handler(q);

	if (q->is_iqdio_q) {
		/* 
		 * for asynchronous queues, we better check, if the fill
		 * level is too high. for synchronous queues, the fill
		 * level will never be that high. 
		 */
		if (atomic_read(&q->number_of_buffers_used)>
		    IQDIO_FILL_LEVEL_TO_POLL)
			qdio_mark_q(q);

	} else if (!q->hydra_gives_outbound_pcis)
		if (!qdio_is_outbound_q_done(q))
			qdio_mark_q(q);

	qdio_release_q(q);
}

static void
qdio_outbound_processing(struct qdio_q *q)
{
	__qdio_outbound_processing(q);
}

/************************* INBOUND ROUTINES *******************************/


static inline int
qdio_get_inbound_buffer_frontier(struct qdio_q *q)
{
	int f,f_mod_no;
	volatile char *slsb;
	int first_not_to_check;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif /* CONFIG_QDIO_DEBUG */
#ifdef QDIO_USE_PROCESSING_STATE
	int last_position=-1;
#endif /* QDIO_USE_PROCESSING_STATE */

	QDIO_DBF_TEXT4(0,trace,"getibfro");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

	slsb=&q->slsb.acc.val[0];
	f_mod_no=f=q->first_to_check;
	/* 
	 * we don't check 128 buffers, as otherwise qdio_has_inbound_q_moved
	 * would return 0 
	 */
	first_not_to_check=f+qdio_min(atomic_read(&q->number_of_buffers_used),
				      (QDIO_MAX_BUFFERS_PER_Q-1));

	/* 
	 * we don't use this one, as a PCI or we after a thin interrupt
	 * will sync the queues
	 */
	/* SYNC_MEMORY;*/

check_next:
	f_mod_no=f&(QDIO_MAX_BUFFERS_PER_Q-1);
	if (f==first_not_to_check) 
		goto out;
	switch (slsb[f_mod_no]) {

	/* CU_EMPTY means frontier is reached */
	case SLSB_CU_INPUT_EMPTY:
		QDIO_DBF_TEXT5(0,trace,"inptempt");
		break;

	/* P_PRIMED means set slsb to P_PROCESSING and move on */
	case SLSB_P_INPUT_PRIMED:
		QDIO_DBF_TEXT5(0,trace,"inptprim");

#ifdef QDIO_USE_PROCESSING_STATE
		/* 
		 * as soon as running under VM, polling the input queues will
		 * kill VM in terms of CP overhead 
		 */
		if (q->siga_sync) {
			set_slsb(&slsb[f_mod_no],SLSB_P_INPUT_NOT_INIT);
		} else {
			/* set the previous buffer to NOT_INIT. The current
			 * buffer will be set to PROCESSING at the end of
			 * this function to avoid further interrupts. */
			if (last_position>=0)
				set_slsb(&slsb[last_position],
					 SLSB_P_INPUT_NOT_INIT);
			atomic_set(&q->polling,1);
			last_position=f_mod_no;
		}
#else /* QDIO_USE_PROCESSING_STATE */
		set_slsb(&slsb[f_mod_no],SLSB_P_INPUT_NOT_INIT);
#endif /* QDIO_USE_PROCESSING_STATE */
		/* 
		 * not needed, as the inbound queue will be synced on the next
		 * siga-r, resp. tiqdio_is_inbound_q_done will do the siga-s
		 */
		/*SYNC_MEMORY;*/
		f++;
		atomic_dec(&q->number_of_buffers_used);
		goto check_next;

	case SLSB_P_INPUT_NOT_INIT:
	case SLSB_P_INPUT_PROCESSING:
		QDIO_DBF_TEXT5(0,trace,"inpnipro");
		break;

	/* P_ERROR means frontier is reached, break and report error */
	case SLSB_P_INPUT_ERROR:
#ifdef CONFIG_QDIO_DEBUG
		sprintf(dbf_text,"inperr%2x",f_mod_no);
		QDIO_DBF_TEXT3(1,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */
		QDIO_DBF_HEX2(1,sbal,q->sbal[f_mod_no],256);

		/* kind of process the buffer */
		set_slsb(&slsb[f_mod_no],SLSB_P_INPUT_NOT_INIT);

		if (q->qdio_error)
			q->error_status_flags|=
				QDIO_STATUS_MORE_THAN_ONE_QDIO_ERROR;
		q->qdio_error=SLSB_P_INPUT_ERROR;
		q->error_status_flags|=QDIO_STATUS_LOOK_FOR_ERROR;

		/* we increment the frontier, as this buffer
		 * was processed obviously */
		f_mod_no=(f_mod_no+1)&(QDIO_MAX_BUFFERS_PER_Q-1);
		atomic_dec(&q->number_of_buffers_used);

#ifdef QDIO_USE_PROCESSING_STATE
		last_position=-1;
#endif /* QDIO_USE_PROCESSING_STATE */

		break;

	/* everything else means frontier not changed (HALTED or so) */
	default: 
		break;
	}
out:
	q->first_to_check=f_mod_no;

#ifdef QDIO_USE_PROCESSING_STATE
	if (last_position>=0)
		set_slsb(&slsb[last_position],SLSB_P_INPUT_PROCESSING);
#endif /* QDIO_USE_PROCESSING_STATE */

	QDIO_DBF_HEX4(0,trace,&q->first_to_check,sizeof(int));

	return q->first_to_check;
}

static inline int
qdio_has_inbound_q_moved(struct qdio_q *q)
{
	int i;

#ifdef QDIO_PERFORMANCE_STATS
	static int old_pcis=0;
	static int old_thinints=0;

	if ((old_pcis==perf_stats.pcis)&&(old_thinints==perf_stats.thinints))
		perf_stats.start_time_inbound=NOW;
	else
		old_pcis=perf_stats.pcis;
#endif /* QDIO_PERFORMANCE_STATS */

	i=qdio_get_inbound_buffer_frontier(q);
	if ( (i!=GET_SAVED_FRONTIER(q)) ||
	     (q->error_status_flags&QDIO_STATUS_LOOK_FOR_ERROR) ) {
		SAVE_FRONTIER(q,i);
		if ((!q->siga_sync)&&(!q->hydra_gives_outbound_pcis))
			SAVE_TIMESTAMP(q);

		QDIO_DBF_TEXT4(0,trace,"inhasmvd");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		return 1;
	} else {
		QDIO_DBF_TEXT4(0,trace,"inhsntmv");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		return 0;
	}
}

/* means, no more buffers to be filled */
static inline int
tiqdio_is_inbound_q_done(struct qdio_q *q)
{
	int no_used;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif

	no_used=atomic_read(&q->number_of_buffers_used);

	/* propagate the change from 82 to 80 through VM */
	SYNC_MEMORY;

#ifdef CONFIG_QDIO_DEBUG
	if (no_used) {
		sprintf(dbf_text,"iqisnt%02x",no_used);
		QDIO_DBF_TEXT4(0,trace,dbf_text);
	} else {
		QDIO_DBF_TEXT4(0,trace,"iniqisdo");
	}
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
#endif /* CONFIG_QDIO_DEBUG */

	if (!no_used)
		return 1;

	if (!q->siga_sync)
		/* we'll check for more primed buffers in qeth_stop_polling */
		return 0;

	if (q->slsb.acc.val[q->first_to_check]!=SLSB_P_INPUT_PRIMED)
		/* 
		 * nothing more to do, if next buffer is not PRIMED.
		 * note that we did a SYNC_MEMORY before, that there
		 * has been a sychnronization.
		 * we will return 0 below, as there is nothing to do
		 * (stop_polling not necessary, as we have not been
		 * using the PROCESSING state 
		 */
		return 0;

	/* 
	 * ok, the next input buffer is primed. that means, that device state 
	 * change indicator and adapter local summary are set, so we will find
	 * it next time.
	 * we will return 0 below, as there is nothing to do, except scheduling
	 * ourselves for the next time. 
	 */
	tiqdio_set_summary_bit((__u32*)q->dev_st_chg_ind);
	tiqdio_sched_tl();
	return 0;
}

static inline int
qdio_is_inbound_q_done(struct qdio_q *q)
{
	int no_used;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif

	no_used=atomic_read(&q->number_of_buffers_used);

	/* 
	 * we need that one for synchronization with the adapter, as it
	 * does a kind of PCI avoidance 
	 */
	SYNC_MEMORY;

	if (!no_used) {
		QDIO_DBF_TEXT4(0,trace,"inqisdnA");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		QDIO_DBF_TEXT4(0,trace,dbf_text);
		return 1;
	}

	if (q->slsb.acc.val[q->first_to_check]==SLSB_P_INPUT_PRIMED) {
		/* we got something to do */
		QDIO_DBF_TEXT4(0,trace,"inqisntA");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		return 0;
	}

	/* on VM, we don't poll, so the q is always done here */
	if (q->siga_sync)
		return 1;
	if (q->hydra_gives_outbound_pcis)
		return 1;

	/* 
	 * at this point we know, that inbound first_to_check
	 * has (probably) not moved (see qdio_inbound_processing) 
	 */
	if (NOW>GET_SAVED_TIMESTAMP(q)+q->timing.threshold) {
#ifdef CONFIG_QDIO_DEBUG
		QDIO_DBF_TEXT4(0,trace,"inqisdon");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		sprintf(dbf_text,"pf%02xcn%02x",q->first_to_check,no_used);
		QDIO_DBF_TEXT4(0,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */
		return 1;
	} else {
#ifdef CONFIG_QDIO_DEBUG
		QDIO_DBF_TEXT4(0,trace,"inqisntd");
		QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));
		sprintf(dbf_text,"pf%02xcn%02x",q->first_to_check,no_used);
		QDIO_DBF_TEXT4(0,trace,dbf_text);
#endif /* CONFIG_QDIO_DEBUG */
		return 0;
	}
}

static inline void
qdio_kick_inbound_handler(struct qdio_q *q)
{
	int count, start, end, real_end, i;
#ifdef CONFIG_QDIO_DEBUG
	char dbf_text[15];
#endif

	QDIO_DBF_TEXT4(0,trace,"kickinh");
	QDIO_DBF_HEX4(0,trace,&q,sizeof(void*));

  	start=q->first_element_to_kick;
 	real_end=q->first_to_check;
 	end=(real_end+QDIO_MAX_BUFFERS_PER_Q-1)&(QDIO_MAX_BUFFERS_PER_Q-1);
 
 	i=start;