aic7xxx_linux.c

自己根据lkd和情境分析

		} else
			dev->flags |= AHC_DEV_Q_BASIC;
	} else {
		/* We can only have one opening */
		dev->maxtags = 0;
		dev->openings =  1 - dev->active;
	}
}

int
ahc_platform_abort_scbs(struct ahc_softc *ahc, int target, char channel,
			int lun, u_int tag, role_t role, uint32_t status)
{
	int chan;
	int maxchan;
	int targ;
	int maxtarg;
	int clun;
	int maxlun;
	int count;

	if (tag != SCB_LIST_NULL)
		return (0);

	chan = 0;
	if (channel != ALL_CHANNELS) {
		chan = channel - 'A';
		maxchan = chan + 1;
	} else {
		maxchan = (ahc->features & AHC_TWIN) ? 2 : 1;
	}
	targ = 0;
	if (target != CAM_TARGET_WILDCARD) {
		targ = target;
		maxtarg = targ + 1;
	} else {
		maxtarg = (ahc->features & AHC_WIDE) ? 16 : 8;
	}
	clun = 0;
	if (lun != CAM_LUN_WILDCARD) {
		clun = lun;
		maxlun = clun + 1;
	} else {
		maxlun = 16;
	}

	count = 0;
	for (; chan < maxchan; chan++) {
		for (; targ < maxtarg; targ++) {
			for (; clun < maxlun; clun++) {
				struct ahc_linux_device *dev;
				struct ahc_busyq *busyq;
				struct ahc_cmd *acmd;

				dev = ahc_linux_get_device(ahc, chan,
							   targ, clun,
							   /*alloc*/FALSE);
				if (dev == NULL)
					continue;

				busyq = &dev->busyq;
				while ((acmd = TAILQ_FIRST(busyq)) != NULL) {
					Scsi_Cmnd *cmd;

					cmd = &acmd_scsi_cmd(acmd);
					TAILQ_REMOVE(busyq, acmd,
						     acmd_links.tqe);
					count++;
					cmd->result = status << 16;
					ahc_linux_queue_cmd_complete(ahc, cmd);
				}
			}
		}
	}

	return (count);
}

/*
 * Sets the queue depth for each SCSI device hanging
 * off the input host adapter.
 */
static void
ahc_linux_select_queue_depth(struct Scsi_Host * host,
			     Scsi_Device * scsi_devs)
{
	Scsi_Device *device;
	struct	ahc_softc *ahc;
	u_long	flags;
	int	scbnum;

	ahc = *((struct ahc_softc **)host->hostdata);
	ahc_lock(ahc, &flags);
	scbnum = 0;
	for (device = scsi_devs; device != NULL; device = device->next) {
		if (device->host == host) {
			ahc_linux_device_queue_depth(ahc, device);
			scbnum += device->queue_depth;
		}
	}
	ahc_unlock(ahc, &flags);
}

/*
 * Determines the queue depth for a given device.
 */
static void
ahc_linux_device_queue_depth(struct ahc_softc *ahc, Scsi_Device * device)
{
	struct	ahc_devinfo devinfo;
	struct	ahc_initiator_tinfo *targ_info;
	struct	ahc_tmode_tstate *tstate;
	uint8_t tags;

	ahc_compile_devinfo(&devinfo,
			    device->channel == 0 ? ahc->our_id : ahc->our_id_b,
			    device->id, device->lun,
			    device->channel == 0 ? 'A' : 'B',
			    ROLE_INITIATOR);
	targ_info = ahc_fetch_transinfo(ahc, devinfo.channel,
					devinfo.our_scsiid,
					devinfo.target, &tstate);

	tags = 0;
	if (device->tagged_supported != 0
	 && (ahc->user_discenable & devinfo.target_mask) != 0) {
		if (ahc->unit >= NUM_ELEMENTS(aic7xxx_tag_info)) {

			printf("aic7xxx: WARNING, insufficient "
			       "tag_info instances for installed "
			       "controllers. Using defaults\n");
			printf("aic7xxx: Please update the "
			       "aic7xxx_tag_info array in the "
			       "aic7xxx.c source file.\n");
			tags = AHC_MAX_QUEUE;
		} else {
			adapter_tag_info_t *tag_info;

			tag_info = &aic7xxx_tag_info[ahc->unit];
			tags = tag_info->tag_commands[devinfo.target_offset];
			if (tags > AHC_MAX_QUEUE)
				tags = AHC_MAX_QUEUE;
		}
	}
	if (tags != 0) {
		device->queue_depth = tags;
		ahc_set_tags(ahc, &devinfo, AHC_QUEUE_TAGGED);
		printf("scsi%d:%c:%d:%d: Tagged Queuing enabled.  Depth %d\n",
	       	       ahc->platform_data->host->host_no, device->channel + 'A',
		       device->id, device->lun, tags);
	} else {
		/*
		 * We allow the OS to queue 2 untagged transactions to
		 * us at any time even though we can only execute them
		 * serially on the controller/device.  This should remove
		 * some latency.
		 */
		device->queue_depth = 2;
	}
}

/*
 * Queue an SCB to the controller.
 */
int
ahc_linux_queue(Scsi_Cmnd * cmd, void (*scsi_done) (Scsi_Cmnd *))
{
	struct	 ahc_softc *ahc;
	struct	 ahc_linux_device *dev;
	u_long	 flags;

	ahc = *(struct ahc_softc **)cmd->host->hostdata;

	/*
	 * Save the callback on completion function.
	 */
	cmd->scsi_done = scsi_done;

	ahc_lock(ahc, &flags);
	dev = ahc_linux_get_device(ahc, cmd->channel, cmd->target,
				   cmd->lun, /*alloc*/TRUE);
	if (dev == NULL) {
		ahc_unlock(ahc, &flags);
		printf("aic7xxx_linux_queue: Unable to allocate device!\n");
		return (-ENOMEM);
	}
	cmd->result = CAM_REQ_INPROG << 16;
	TAILQ_INSERT_TAIL(&dev->busyq, (struct ahc_cmd *)cmd, acmd_links.tqe);
	if ((dev->flags & AHC_DEV_ON_RUN_LIST) == 0) {
		TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq, dev, links);
		dev->flags |= AHC_DEV_ON_RUN_LIST;
		ahc_linux_run_device_queues(ahc);
	}
	ahc_unlock(ahc, &flags);
	return (0);
}

static void
ahc_linux_run_device_queue(struct ahc_softc *ahc, struct ahc_linux_device *dev)
{
	struct	 ahc_cmd *acmd;
	struct	 scsi_cmnd *cmd;
	struct	 scb *scb;
	struct	 hardware_scb *hscb;
	struct	 ahc_initiator_tinfo *tinfo;
	struct	 ahc_tmode_tstate *tstate;
	uint16_t mask;

	if ((dev->flags & AHC_DEV_ON_RUN_LIST) != 0)
		panic("running device on run list");

	while ((acmd = TAILQ_FIRST(&dev->busyq)) != NULL
	    && dev->openings > 0 && dev->qfrozen == 0) {

		/*
		 * Schedule us to run later.  The only reason we are not
		 * running is because the whole controller Q is frozen.
		 */
		if (ahc->platform_data->qfrozen != 0) {

			TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq,
					  dev, links);
			dev->flags |= AHC_DEV_ON_RUN_LIST;
			return;
		}
		/*
		 * Get an scb to use.
		 */
		if ((scb = ahc_get_scb(ahc)) == NULL) {
			TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq,
					 dev, links);
			dev->flags |= AHC_DEV_ON_RUN_LIST;
			ahc->flags |= AHC_RESOURCE_SHORTAGE;
			return;
		}
		TAILQ_REMOVE(&dev->busyq, acmd, acmd_links.tqe);
		cmd = &acmd_scsi_cmd(acmd);
		scb->io_ctx = cmd;
		scb->platform_data->dev = dev;
		hscb = scb->hscb;
		cmd->host_scribble = (char *)scb;

		/*
		 * Fill out basics of the HSCB.
		 */
		hscb->control = 0;
		hscb->scsiid = BUILD_SCSIID(ahc, cmd);
		hscb->lun = cmd->lun;
		mask = SCB_GET_TARGET_MASK(ahc, scb);
		tinfo = ahc_fetch_transinfo(ahc, SCB_GET_CHANNEL(ahc, scb),
					    SCB_GET_OUR_ID(scb),
					    SCB_GET_TARGET(ahc, scb), &tstate);
		hscb->scsirate = tinfo->scsirate;
		hscb->scsioffset = tinfo->curr.offset;
		if ((tstate->ultraenb & mask) != 0)
			hscb->control |= ULTRAENB;

		if ((ahc->user_discenable & mask) != 0)
			hscb->control |= DISCENB;

		if ((tstate->auto_negotiate & mask) != 0) {
			scb->flags |= SCB_AUTO_NEGOTIATE;
			scb->hscb->control |= MK_MESSAGE;
		}

		if ((dev->flags & (AHC_DEV_Q_TAGGED|AHC_DEV_Q_BASIC)) != 0) {
			if (dev->commands_since_idle_or_otag == AHC_OTAG_THRESH
			 && (dev->flags & AHC_DEV_Q_TAGGED) != 0) {
				hscb->control |= MSG_ORDERED_TASK;
				dev->commands_since_idle_or_otag = 0;
			} else {
				hscb->control |= MSG_SIMPLE_TASK;
			}
		}

		hscb->cdb_len = cmd->cmd_len;
		if (hscb->cdb_len <= 12) {
			memcpy(hscb->shared_data.cdb, cmd->cmnd, hscb->cdb_len);
		} else {
			memcpy(hscb->cdb32, cmd->cmnd, hscb->cdb_len);
			scb->flags |= SCB_CDB32_PTR;
		}

		scb->platform_data->xfer_len = 0;
		ahc_set_residual(scb, 0);
		ahc_set_sense_residual(scb, 0);
		if (cmd->use_sg != 0) {
			struct	ahc_dma_seg *sg;
			struct	scatterlist *cur_seg;
			struct	scatterlist *end_seg;
			int	nseg;

			cur_seg = (struct scatterlist *)cmd->request_buffer;
			nseg = pci_map_sg(ahc->dev_softc, cur_seg, cmd->use_sg,
				 scsi_to_pci_dma_dir(cmd ->sc_data_direction));
			end_seg = cur_seg + nseg;
			/* Copy the segments into the SG list. */
			sg = scb->sg_list;
			/*
			 * The sg_count may be larger than nseg if
			 * a transfer crosses a 32bit page.
			 */ 
			scb->sg_count = 0;
			while(cur_seg < end_seg) {
				bus_addr_t addr;
				bus_size_t len;
				int consumed;

				addr = sg_dma_address(cur_seg);
				len = sg_dma_len(cur_seg);
				consumed = ahc_linux_map_seg(ahc, scb,
							     sg, addr, len);
				sg += consumed;
				scb->sg_count += consumed;
				cur_seg++;
			}
			sg--;
			sg->len |= ahc_htole32(AHC_DMA_LAST_SEG);

			/*
			 * Reset the sg list pointer.
			 */
			scb->hscb->sgptr =
			    ahc_htole32(scb->sg_list_phys | SG_FULL_RESID);

			/*
			 * Copy the first SG into the "current"
			 * data pointer area.
			 */
			scb->hscb->dataptr = scb->sg_list->addr;
			scb->hscb->datacnt = scb->sg_list->len;
		} else if (cmd->request_bufflen != 0) {
			struct	 ahc_dma_seg *sg;
			bus_addr_t addr;

			sg = scb->sg_list;
			addr = pci_map_single(ahc->dev_softc,
			       cmd->request_buffer,
			       cmd->request_bufflen,
			       scsi_to_pci_dma_dir(cmd->sc_data_direction));
			scb->sg_count = 0;
			scb->sg_count = ahc_linux_map_seg(ahc, scb,
							  sg, addr,
							  cmd->request_bufflen);
			sg->len |= ahc_htole32(AHC_DMA_LAST_SEG);

			/*
			 * Reset the sg list pointer.
			 */
			scb->hscb->sgptr =
			    ahc_htole32(scb->sg_list_phys | SG_FULL_RESID);

			/*
			 * Copy the first SG into the "current"
			 * data pointer area.
			 */
			scb->hscb->dataptr = sg->addr;
			scb->hscb->datacnt = sg->len;
		} else {
			scb->hscb->sgptr = ahc_htole32(SG_LIST_NULL);
			scb->hscb->dataptr = 0;
			scb->hscb->datacnt = 0;
			scb->sg_count = 0;
		}

		ahc_sync_sglist(ahc, scb, BUS_DMASYNC_PREWRITE);
		LIST_INSERT_HEAD(&ahc->pending_scbs, scb, pending_links);
		dev->openings--;
		dev->active++;
		dev->commands_issued++;
		if ((dev->flags & AHC_DEV_PERIODIC_OTAG) != 0)
			dev->commands_since_idle_or_otag++;

		/*
		 * We only allow one untagged transaction
		 * per target in the initiator role unless
		 * we are storing a full busy target *lun*
		 * table in SCB space.
		 */
		if ((scb->hscb->control & (TARGET_SCB|TAG_ENB)) == 0
		 && (ahc->features & AHC_SCB_BTT) == 0) {
			struct scb_tailq *untagged_q;
			int target_offset;

			target_offset = SCB_GET_TARGET_OFFSET(ahc, scb);
			untagged_q = &(ahc->untagged_queues[target_offset]);
			TAILQ_INSERT_TAIL(untagged_q, scb, links.tqe);
			scb->flags |= SCB_UNTAGGEDQ;
			if (TAILQ_FIRST(untagged_q) != scb)
				continue;
		}
		scb->flags |= SCB_ACTIVE;
		ahc_queue_scb(ahc, scb);
	}
}

/*
 * SCSI controller interrupt handler.
 */
void
ahc_linux_isr(int irq, void *dev_id, struct pt_regs * regs)
{
	struct ahc_softc *ahc;
	struct ahc_cmd *acmd;
	u_long flags;

	ahc = (struct ahc_softc *) dev_id;
	ahc_lock(ahc, &flags); 
	ahc_intr(ahc);
	/*
	 * It would be nice to run the device queues from a
	 * bottom half handler, but as there is no way to
	 * dynamically register one, we'll have to postpone
	 * that until we get integrated into the kernel.
	 */
	ahc_linux_run_device_queues(ahc);
	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
	TAILQ_INIT(&ahc->platform_data->completeq);
	ahc_unlock(ahc, &flags);
	if (acmd != NULL)
		ahc_linux_run_complete_queue(ahc, acmd);
}

void
ahc_platform_flushwork(struct ahc_softc *ahc)
{
	struct ahc_cmd *acmd;

	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
	TAILQ_INIT(&ahc->platform_data->completeq);
	if (acmd != NULL)
		ahc_linux_run_complete_queue(ahc, acmd);
}

static struct ahc_linux_target*
ahc_linux_alloc_target(struct ahc_softc *ahc, u_int channel, u_int target)
{
	struct ahc_linux_target *targ;
	u_int target_offset;

	targ = malloc(sizeof(*targ), M_DEVBUG, M_NOWAIT);
	if (targ == NULL)
		return (NULL);
	memset(targ, 0, sizeof(*targ));
	targ->channel = channel;
	targ->target = target;
	target_offset = target;
	if (channel != 0)
		target_offset += 8;
	ahc->platform_data->targets[target_offset] = targ;
	return (targ);
}

static void
ahc_linux_free_target(struct ahc_softc *ahc, struct ahc_linux_target *targ)