ncr53c9x.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

				/* see how much we got ... */
				fifocnt = (esp_read(eregs->esp_fflags) & ESP_FF_FBYTES);

				if (!fifocnt)
					fifo_stuck++;
				else
					fifo_stuck = 0;

				ESPDATA(("\rgot %d st %x ph %x", fifocnt, esp->sreg, newphase));

				/* read fifo */
				for(j=0;j<fifocnt;j++)
					SCptr->SCp.ptr[i++] = esp_read(eregs->esp_fdata);

				ESPDATA(("(%d) ", i));

				/* how many to go ?? */
				hmuch -= fifocnt;

				/* break if status phase !! */
				if(newphase == ESP_STATP) {
					/* clear int. */
					esp->ireg = esp_read(eregs->esp_intrpt);
					break;
				}
			} else {
#define MAX_FIFO 8
				/* how much will fit ? */
				int this_count = MAX_FIFO - fifocnt;
				if (this_count > hmuch)
					this_count = hmuch;

				/* fill fifo */
				for(j=0;j<this_count;j++)
					esp_write(eregs->esp_fdata, SCptr->SCp.ptr[i++]);

				/* how many left if this goes out ?? */
				hmuch -= this_count;

				/* 'go' ... */ 
				esp_cmd(esp, eregs, ESP_CMD_TI);

				/* wait for 'got it' */
				timeout = 1000000;
				while (!((esp->sreg=esp_read(eregs->esp_status)) & ESP_STAT_INTR) && --timeout)
					udelay(2);
				if (timeout == 0)
					printk("DRQ dataout timeout!  \n");

				newphase = esp->sreg & ESP_STAT_PMASK;

				/* need to check how much was sent ?? */
				fifocnt = (esp_read(eregs->esp_fflags) & ESP_FF_FBYTES);

				ESPDATA(("\rsent %d st %x ph %x", this_count - fifocnt, esp->sreg, newphase));

				ESPDATA(("(%d) ", i));

				/* break if status phase !! */
				if(newphase == ESP_STATP) {
					/* clear int. */
					esp->ireg = esp_read(eregs->esp_intrpt);
					break;
				}

			}

			/* clear int. */
			esp->ireg = esp_read(eregs->esp_intrpt);

			ESPDATA(("ir %x ... ", esp->ireg));

			if (hmuch == 0)
				ESPDATA(("done! \n"));

			restore_flags(flags);

			/* check new bus phase */
			if (newphase != oldphase && i < esp->current_transfer_size) {
				/* something happened; disconnect ?? */
				ESPDATA(("phase change, dropped out with %d done ... ", i));
				break;
			}

			/* check int. status */
			if (esp->ireg & ESP_INTR_DC) {
				/* disconnect */
				ESPDATA(("disconnect; %d transfered ... ", i));
				break;
			} else if (esp->ireg & ESP_INTR_FDONE) {
				/* function done */
				ESPDATA(("function done; %d transfered ... ", i));
				break;
			}

			/* XXX fixme: bail out on stall */
			if (fifo_stuck > 10) {
				/* we're stuck */
				ESPDATA(("fifo stall; %d transfered ... ", i));
				break;
			}
		}

		ESPDATA(("\n"));
		/* check successful completion ?? */

		if (thisphase == in_dataout)
			hmuch += fifocnt; /* stuck?? adjust data pointer ...*/

		/* tell do_data_finale how much was transfered */
		esp->current_transfer_size -= hmuch;

		/* still not completely sure on this one ... */		
		return /*do_intr_end*/ do_work_bus /*do_phase_determine*/ ;

		/*
		 * end PIO
		 */
	}
	return do_intr_end;
}

/* See how successful the data transfer was. */
static int esp_do_data_finale(struct NCR_ESP *esp,
			      struct ESP_regs *eregs)
{
	Scsi_Cmnd *SCptr = esp->current_SC;
	int bogus_data = 0, bytes_sent = 0, fifocnt, ecount = 0;

	if(esp->dma_led_off)
		esp->dma_led_off(esp);

	ESPDATA(("esp_do_data_finale: "));

	if(SCptr->SCp.phase == in_datain) {
		if(esp->sreg & ESP_STAT_PERR) {
			/* Yuck, parity error.  The ESP asserts ATN
			 * so that we can go to message out phase
			 * immediately and inform the target that
			 * something bad happened.
			 */
			ESPLOG(("esp%d: data bad parity detected.\n",
				esp->esp_id));
			esp->cur_msgout[0] = INITIATOR_ERROR;
			esp->msgout_len = 1;
		}
		if(esp->dma_drain)
			esp->dma_drain(esp);
	}
	if(esp->dma_invalidate)
		esp->dma_invalidate(esp);

	/* This could happen for the above parity error case. */
	if(!(esp->ireg == ESP_INTR_BSERV)) {
		/* Please go to msgout phase, please please please... */
		ESPLOG(("esp%d: !BSERV after data, probably to msgout\n",
			esp->esp_id));
		return esp_do_phase_determine(esp, eregs);
	}	

	/* Check for partial transfers and other horrible events. */
	fifocnt = (esp_read(eregs->esp_fflags) & ESP_FF_FBYTES);
	ecount = esp_getcount(eregs);
	if(esp->fas_premature_intr_workaround)
		ecount -= 0x40;
	bytes_sent = esp->current_transfer_size;

	ESPDATA(("trans_sz=%d, ", bytes_sent));
	if(!(esp->sreg & ESP_STAT_TCNT))
		bytes_sent -= ecount;
	if(SCptr->SCp.phase == in_dataout)
		bytes_sent -= fifocnt;

	ESPDATA(("bytes_sent=%d (ecount=%d, fifocnt=%d), ", bytes_sent,
		 ecount, fifocnt));

	/* If we were in synchronous mode, check for peculiarities. */
	if(SCptr->device->sync_max_offset)
		bogus_data = esp100_sync_hwbug(esp, eregs, SCptr, fifocnt);
	else
		esp_cmd(esp, eregs, ESP_CMD_FLUSH);

	/* Until we are sure of what has happened, we are certainly
	 * in the dark.
	 */
	esp_advance_phase(SCptr, in_the_dark);

	/* Check for premature interrupt condition. Can happen on FAS2x6
	 * chips. QLogic recommends a workaround by overprogramming the
	 * transfer counters, but this makes doing scatter-gather impossible.
	 * Until there is a way to disable scatter-gather for a single target,
	 * and not only for the entire host adapter as it is now, the workaround
	 * is way to expensive performance wise.
	 * Instead, it turns out that when this happens the target has disconnected
	 * allready but it doesn't show in the interrupt register. Compensate for
	 * that here to try and avoid a SCSI bus reset.
	 */
	if(!esp->fas_premature_intr_workaround && (fifocnt == 1) &&
	   sreg_dataoutp(esp->sreg)) {
		ESPLOG(("esp%d: Premature interrupt, enabling workaround\n",
			esp->esp_id));
#if 0
		/* Disable scatter-gather operations, they are not possible
		 * when using this workaround.
		 */
		esp->ehost->sg_tablesize = 0;
		esp->ehost->use_clustering = ENABLE_CLUSTERING;
		esp->fas_premature_intr_workaround = 1;
		bytes_sent = 0;
		if(SCptr->use_sg) {
			ESPLOG(("esp%d: Aborting scatter-gather operation\n",
				esp->esp_id));
			esp->cur_msgout[0] = ABORT;
			esp->msgout_len = 1;
			esp->msgout_ctr = 0;
			esp_cmd(esp, eregs, ESP_CMD_SATN);
			esp_setcount(eregs, 0xffff);
			esp_cmd(esp, eregs, ESP_CMD_NULL);
			esp_cmd(esp, eregs, ESP_CMD_TPAD | ESP_CMD_DMA);
			return do_intr_end;
		}
#else
		/* Just set the disconnected bit. That's what appears to
		 * happen anyway. The state machine will pick it up when
		 * we return.
		 */
		esp->ireg |= ESP_INTR_DC;
#endif
        }

	if(bytes_sent < 0) {
		/* I've seen this happen due to lost state in this
		 * driver.  No idea why it happened, but allowing
		 * this value to be negative caused things to
		 * lock up.  This allows greater chance of recovery.
		 * In fact every time I've seen this, it has been
		 * a driver bug without question.
		 */
		ESPLOG(("esp%d: yieee, bytes_sent < 0!\n", esp->esp_id));
		ESPLOG(("esp%d: csz=%d fifocount=%d ecount=%d\n",
			esp->esp_id,
			esp->current_transfer_size, fifocnt, ecount));
		ESPLOG(("esp%d: use_sg=%d ptr=%p this_residual=%d\n",
			esp->esp_id,
			SCptr->use_sg, SCptr->SCp.ptr, SCptr->SCp.this_residual));
		ESPLOG(("esp%d: Forcing async for target %d\n", esp->esp_id, 
			SCptr->target));
		SCptr->device->borken = 1;
		SCptr->device->sync = 0;
		bytes_sent = 0;
	}

	/* Update the state of our transfer. */
	SCptr->SCp.ptr += bytes_sent;
	SCptr->SCp.this_residual -= bytes_sent;
	if(SCptr->SCp.this_residual < 0) {
		/* shit */
		ESPLOG(("esp%d: Data transfer overrun.\n", esp->esp_id));
		SCptr->SCp.this_residual = 0;
	}

	/* Maybe continue. */
	if(!bogus_data) {
		ESPDATA(("!bogus_data, "));
		/* NO MATTER WHAT, we advance the scatterlist,
		 * if the target should decide to disconnect
		 * in between scatter chunks (which is common)
		 * we could die horribly!  I used to have the sg
		 * advance occur only if we are going back into
		 * (or are staying in) a data phase, you can
		 * imagine the hell I went through trying to
		 * figure this out.
		 */
		if(!SCptr->SCp.this_residual && SCptr->SCp.buffers_residual)
			advance_sg(esp, SCptr);
#ifdef DEBUG_ESP_DATA
		if(sreg_datainp(esp->sreg) || sreg_dataoutp(esp->sreg)) {
			ESPDATA(("to more data\n"));
		} else {
			ESPDATA(("to new phase\n"));
		}
#endif
		return esp_do_phase_determine(esp, eregs);
	}
	/* Bogus data, just wait for next interrupt. */
	ESPLOG(("esp%d: bogus_data during end of data phase\n",
		esp->esp_id));
	return do_intr_end;
}

/* We received a non-good status return at the end of
 * running a SCSI command.  This is used to decide if
 * we should clear our synchronous transfer state for
 * such a device when that happens.
 *
 * The idea is that when spinning up a disk or rewinding
 * a tape, we don't want to go into a loop re-negotiating
 * synchronous capabilities over and over.
 */
static int esp_should_clear_sync(Scsi_Cmnd *sp)
{
	unchar cmd1 = sp->cmnd[0];
	unchar cmd2 = sp->data_cmnd[0];

	/* These cases are for spinning up a disk and
	 * waiting for that spinup to complete.
	 */
	if(cmd1 == START_STOP ||
	   cmd2 == START_STOP)
		return 0;

	if(cmd1 == TEST_UNIT_READY ||
	   cmd2 == TEST_UNIT_READY)
		return 0;

	/* One more special case for SCSI tape drives,
	 * this is what is used to probe the device for
	 * completion of a rewind or tape load operation.
	 */
	if(sp->device->type == TYPE_TAPE) {
		if(cmd1 == MODE_SENSE ||
		   cmd2 == MODE_SENSE)
			return 0;
	}

	return 1;
}

/* Either a command is completing or a target is dropping off the bus
 * to continue the command in the background so we can do other work.
 */
static int esp_do_freebus(struct NCR_ESP *esp, struct ESP_regs *eregs)
{
	Scsi_Cmnd *SCptr = esp->current_SC;
	int rval;

	rval = skipahead2(esp, eregs, SCptr, in_status, in_msgindone, in_freeing);
	if(rval)
		return rval;

	if(esp->ireg != ESP_INTR_DC) {
		ESPLOG(("esp%d: Target will not disconnect\n", esp->esp_id));
		return do_reset_bus; /* target will not drop BSY... */
	}
	esp->msgout_len = 0;
	esp->prevmsgout = NOP;
	if(esp->prevmsgin == COMMAND_COMPLETE) {
		/* Normal end of nexus. */
		if(esp->disconnected_SC)
			esp_cmd(esp, eregs, ESP_CMD_ESEL);

		if(SCptr->SCp.Status != GOOD &&
		   SCptr->SCp.Status != CONDITION_GOOD &&
		   ((1<<SCptr->target) & esp->targets_present) &&
		   SCptr->device->sync &&
		   SCptr->device->sync_max_offset) {
			/* SCSI standard says that the synchronous capabilities
			 * should be renegotiated at this point.  Most likely
			 * we are about to request sense from this target
			 * in which case we want to avoid using sync
			 * transfers until we are sure of the current target
			 * state.
			 */
			ESPMISC(("esp: Status <%d> for target %d lun %d\n",
				 SCptr->SCp.Status, SCptr->target, SCptr->lun));

			/* But don't do this when spinning up a disk at
			 * boot time while we poll for completion as it
			 * fills up the console with messages.  Also, tapes
			 * can report not ready many times right after
			 * loading up a tape.
			 */
			if(esp_should_clear_sync(SCptr) != 0)
				SCptr->device->sync = 0;
		}
		ESPDISC(("F<%02x,%02x>", SCptr->target, SCptr->lun));
		esp_done(esp, ((SCptr->SCp.Status & 0xff) |
			       ((SCptr->SCp.Message & 0xff)<<8) |
			       (DID_OK << 16)));
	} else if(esp->prevmsgin == DISCONNECT) {
		/* Normal disconnect. */
		esp_cmd(esp, eregs, ESP_CMD_ESEL);
		ESPDISC(("D<%02x,%02x>", SCptr->target, SCptr->lun));
		append_SC(&esp->disconnected_SC, SCptr);
		esp->current_SC = NULL;
		if(esp->issue_SC)
			esp_exec_cmd(esp);
	} else {
		/* Driver bug, we do not expect a disconnect here
		 * and should not have advanced the state engine
		 * to in_freeing.
		 */
		ESPLOG(("esp%d: last msg not disc and not cmd cmplt.\n",
			esp->esp_id));
		return do_reset_bus;
	}
	return do_intr_end;
}

/* When a reselect occurs, and we cannot find the command to
 * reconnect to in our queues, we do this.
 */
static int esp_bad_reconnect(struct NCR_ESP *esp)
{
	Scsi_Cmnd *sp;

	ESPLOG(("esp%d: Eieeee, reconnecting unknown command!\n",
		esp->esp_id));
	ESPLOG(("QUEUE DUMP\n"));
	sp = esp->issue_SC;
	ESPLOG(("esp%d: issue_SC[", esp->esp_id));
	while(sp) {
		ESPLOG(("<%02x,%02x>", sp->target, sp->lun));
		sp = (Scsi_Cmnd *) sp->host_scribble;
	}
	ESPLOG(("]\n"));
	sp = esp->current_SC;
	ESPLOG(("esp%d: current_SC[", esp->esp_id));
	while(sp) {
		ESPLOG(("<%02x,%02x>", sp->target, sp->lun));
		sp = (Scsi_Cmnd *) sp->host_scribble;
	}
	ESPLOG(("]\n"));
	sp = esp->disconnected_SC;
	ESPLOG(("esp%d: disconnected_SC[", esp->esp_id));
	while(sp) {
		ESPLOG(("<%02x,%02x>", sp->target, sp->lun));
		sp = (Scsi_Cmnd *) sp->host_scribble;
	}
	ESPLOG(("]\n"));
	return do_reset_bus;
}

/* Do the needy when a target tries to reconnect to us. */
static int esp_do_reconnect(struct NCR_ESP *esp, 
			    struct ESP_regs *eregs)
{
	int lun, target;
	Scsi_Cmnd *SCptr;

	/* Check for all bogus conditions first. */
	target = reconnect_target(esp, eregs);
	if(target < 0) {
		ESPDISC(("bad bus bits\n"));
		return do_reset_bus;
	}
	lun = reconnect_lun(esp, eregs);
	if(lun < 0) {
		ESPDISC(("target=%2x, bad identify msg\n", target));
		return do_reset_bus;
	}

	/* Things look ok... */
	ESPDISC(("R<%02x,%02x>", target, lun));

	esp_cmd(esp, eregs, ESP_CMD_FLUSH);
	if(esp100_reconnect_hwbug(esp, eregs))
		return do_reset_bus;
	esp_cmd(esp, eregs