+ * Work around any chip bugs related to halting sequencer execution.
+ * On Ultra2 controllers, we must clear the CIOBUS stretch signal by
+ * reading a register that will set this signal and deassert it.
+ * Without this workaround, if the chip is paused, by an interrupt or
+ * manual pause while accessing scb ram, accesses to certain registers
+ * will hang the system (infinite pci retries).
+ */
+static void
+ahc_pause_bug_fix(struct ahc_softc *ahc)
+{
+ if ((ahc->features & AHC_ULTRA2) != 0)
+ (void)ahc_inb(ahc, CCSCBCTL);
+}
+
+/*
+ * Determine whether the sequencer has halted code execution.
+ * Returns non-zero status if the sequencer is stopped.
+ */
+int
+ahc_is_paused(struct ahc_softc *ahc)
+{
+ return ((ahc_inb(ahc, HCNTRL) & PAUSE) != 0);
+}
+
+/*
+ * Request that the sequencer stop and wait, indefinitely, for it
+ * to stop. The sequencer will only acknowledge that it is paused
+ * once it has reached an instruction boundary and PAUSEDIS is
+ * cleared in the SEQCTL register. The sequencer may use PAUSEDIS
+ * for critical sections.
+ */
+void
+ahc_pause(struct ahc_softc *ahc)
+{
+ ahc_outb(ahc, HCNTRL, ahc->pause);
+
+ /*
+ * Since the sequencer can disable pausing in a critical section, we
+ * must loop until it actually stops.
+ */
+ while (ahc_is_paused(ahc) == 0)
+ ;
+
+ ahc_pause_bug_fix(ahc);
+}
+
+/*
+ * Allow the sequencer to continue program execution.
+ * We check here to ensure that no additional interrupt
+ * sources that would cause the sequencer to halt have been
+ * asserted. If, for example, a SCSI bus reset is detected
+ * while we are fielding a different, pausing, interrupt type,
+ * we don't want to release the sequencer before going back
+ * into our interrupt handler and dealing with this new
+ * condition.
+ */
+void
+ahc_unpause(struct ahc_softc *ahc)
+{
+ if ((ahc_inb(ahc, INTSTAT) & (SCSIINT | SEQINT | BRKADRINT)) == 0)
+ ahc_outb(ahc, HCNTRL, ahc->unpause);
+}
+
+/************************** Memory mapping routines ***************************/
+static struct ahc_dma_seg *
+ahc_sg_bus_to_virt(struct scb *scb, uint32_t sg_busaddr)
+{
+ int sg_index;
+
+ sg_index = (sg_busaddr - scb->sg_list_phys)/sizeof(struct ahc_dma_seg);
+ /* sg_list_phys points to entry 1, not 0 */
+ sg_index++;
+
+ return (&scb->sg_list[sg_index]);
+}
+
+static uint32_t
+ahc_sg_virt_to_bus(struct scb *scb, struct ahc_dma_seg *sg)
+{
+ int sg_index;
+
+ /* sg_list_phys points to entry 1, not 0 */
+ sg_index = sg - &scb->sg_list[1];
+
+ return (scb->sg_list_phys + (sg_index * sizeof(*scb->sg_list)));
+}
+
+static uint32_t
+ahc_hscb_busaddr(struct ahc_softc *ahc, u_int index)
+{
+ return (ahc->scb_data->hscb_busaddr
+ + (sizeof(struct hardware_scb) * index));
+}
+
+static void
+ahc_sync_scb(struct ahc_softc *ahc, struct scb *scb, int op)
+{
+ ahc_dmamap_sync(ahc, ahc->scb_data->hscb_dmat,
+ ahc->scb_data->hscb_dmamap,
+ /*offset*/(scb->hscb - ahc->hscbs) * sizeof(*scb->hscb),
+ /*len*/sizeof(*scb->hscb), op);
+}
+
+void
+ahc_sync_sglist(struct ahc_softc *ahc, struct scb *scb, int op)
+{
+ if (scb->sg_count == 0)
+ return;
+
+ ahc_dmamap_sync(ahc, ahc->scb_data->sg_dmat, scb->sg_map->sg_dmamap,
+ /*offset*/(scb->sg_list - scb->sg_map->sg_vaddr)
+ * sizeof(struct ahc_dma_seg),
+ /*len*/sizeof(struct ahc_dma_seg) * scb->sg_count, op);
+}
+
+#ifdef AHC_TARGET_MODE
+static uint32_t
+ahc_targetcmd_offset(struct ahc_softc *ahc, u_int index)
+{
+ return (((uint8_t *)&ahc->targetcmds[index]) - ahc->qoutfifo);
+}
+#endif
+
+/*********************** Miscelaneous Support Functions ***********************/
+/*
+ * Determine whether the sequencer reported a residual
+ * for this SCB/transaction.
+ */
+static void
+ahc_update_residual(struct ahc_softc *ahc, struct scb *scb)
+{
+ uint32_t sgptr;
+
+ sgptr = ahc_le32toh(scb->hscb->sgptr);
+ if ((sgptr & SG_RESID_VALID) != 0)
+ ahc_calc_residual(ahc, scb);
+}
+
+/*
+ * Return pointers to the transfer negotiation information
+ * for the specified our_id/remote_id pair.
+ */
+struct ahc_initiator_tinfo *
+ahc_fetch_transinfo(struct ahc_softc *ahc, char channel, u_int our_id,
+ u_int remote_id, struct ahc_tmode_tstate **tstate)
+{
+ /*
+ * Transfer data structures are stored from the perspective
+ * of the target role. Since the parameters for a connection
+ * in the initiator role to a given target are the same as
+ * when the roles are reversed, we pretend we are the target.
+ */
+ if (channel == 'B')
+ our_id += 8;
+ *tstate = ahc->enabled_targets[our_id];
+ return (&(*tstate)->transinfo[remote_id]);
+}
+
+uint16_t
+ahc_inw(struct ahc_softc *ahc, u_int port)
+{
+ uint16_t r = ahc_inb(ahc, port+1) << 8;
+ return r | ahc_inb(ahc, port);
+}
+
+void
+ahc_outw(struct ahc_softc *ahc, u_int port, u_int value)
+{
+ ahc_outb(ahc, port, value & 0xFF);
+ ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
+}
+
+uint32_t
+ahc_inl(struct ahc_softc *ahc, u_int port)
+{
+ return ((ahc_inb(ahc, port))
+ | (ahc_inb(ahc, port+1) << 8)
+ | (ahc_inb(ahc, port+2) << 16)
+ | (ahc_inb(ahc, port+3) << 24));
+}
+
+void
+ahc_outl(struct ahc_softc *ahc, u_int port, uint32_t value)
+{
+ ahc_outb(ahc, port, (value) & 0xFF);
+ ahc_outb(ahc, port+1, ((value) >> 8) & 0xFF);
+ ahc_outb(ahc, port+2, ((value) >> 16) & 0xFF);
+ ahc_outb(ahc, port+3, ((value) >> 24) & 0xFF);
+}
+
+uint64_t
+ahc_inq(struct ahc_softc *ahc, u_int port)
+{
+ return ((ahc_inb(ahc, port))
+ | (ahc_inb(ahc, port+1) << 8)
+ | (ahc_inb(ahc, port+2) << 16)
+ | (ahc_inb(ahc, port+3) << 24)
+ | (((uint64_t)ahc_inb(ahc, port+4)) << 32)
+ | (((uint64_t)ahc_inb(ahc, port+5)) << 40)
+ | (((uint64_t)ahc_inb(ahc, port+6)) << 48)
+ | (((uint64_t)ahc_inb(ahc, port+7)) << 56));
+}
+
+void
+ahc_outq(struct ahc_softc *ahc, u_int port, uint64_t value)
+{
+ ahc_outb(ahc, port, value & 0xFF);
+ ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
+ ahc_outb(ahc, port+2, (value >> 16) & 0xFF);
+ ahc_outb(ahc, port+3, (value >> 24) & 0xFF);
+ ahc_outb(ahc, port+4, (value >> 32) & 0xFF);
+ ahc_outb(ahc, port+5, (value >> 40) & 0xFF);
+ ahc_outb(ahc, port+6, (value >> 48) & 0xFF);
+ ahc_outb(ahc, port+7, (value >> 56) & 0xFF);
+}
+
+/*
+ * Get a free scb. If there are none, see if we can allocate a new SCB.
+ */
+struct scb *
+ahc_get_scb(struct ahc_softc *ahc)
+{
+ struct scb *scb;
+
+ if ((scb = SLIST_FIRST(&ahc->scb_data->free_scbs)) == NULL) {
+ ahc_alloc_scbs(ahc);
+ scb = SLIST_FIRST(&ahc->scb_data->free_scbs);
+ if (scb == NULL)
+ return (NULL);
+ }
+ SLIST_REMOVE_HEAD(&ahc->scb_data->free_scbs, links.sle);
+ return (scb);
+}
+
+/*
+ * Return an SCB resource to the free list.
+ */
+void
+ahc_free_scb(struct ahc_softc *ahc, struct scb *scb)
+{
+ struct hardware_scb *hscb;
+
+ hscb = scb->hscb;
+ /* Clean up for the next user */
+ ahc->scb_data->scbindex[hscb->tag] = NULL;
+ scb->flags = SCB_FREE;
+ hscb->control = 0;
+
+ SLIST_INSERT_HEAD(&ahc->scb_data->free_scbs, scb, links.sle);
+
+ /* Notify the OSM that a resource is now available. */
+ ahc_platform_scb_free(ahc, scb);
+}
+
+struct scb *
+ahc_lookup_scb(struct ahc_softc *ahc, u_int tag)
+{
+ struct scb* scb;
+
+ scb = ahc->scb_data->scbindex[tag];
+ if (scb != NULL)
+ ahc_sync_scb(ahc, scb,
+ BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
+ return (scb);
+}
+
+static void
+ahc_swap_with_next_hscb(struct ahc_softc *ahc, struct scb *scb)
+{
+ struct hardware_scb *q_hscb;
+ u_int saved_tag;
+
+ /*
+ * Our queuing method is a bit tricky. The card
+ * knows in advance which HSCB to download, and we
+ * can't disappoint it. To achieve this, the next
+ * SCB to download is saved off in ahc->next_queued_scb.
+ * When we are called to queue "an arbitrary scb",
+ * we copy the contents of the incoming HSCB to the one
+ * the sequencer knows about, swap HSCB pointers and
+ * finally assign the SCB to the tag indexed location
+ * in the scb_array. This makes sure that we can still
+ * locate the correct SCB by SCB_TAG.
+ */
+ q_hscb = ahc->next_queued_scb->hscb;
+ saved_tag = q_hscb->tag;
+ memcpy(q_hscb, scb->hscb, sizeof(*scb->hscb));
+ if ((scb->flags & SCB_CDB32_PTR) != 0) {
+ q_hscb->shared_data.cdb_ptr =
+ ahc_htole32(ahc_hscb_busaddr(ahc, q_hscb->tag)
+ + offsetof(struct hardware_scb, cdb32));
+ }
+ q_hscb->tag = saved_tag;
+ q_hscb->next = scb->hscb->tag;
+
+ /* Now swap HSCB pointers. */
+ ahc->next_queued_scb->hscb = scb->hscb;
+ scb->hscb = q_hscb;
+
+ /* Now define the mapping from tag to SCB in the scbindex */
+ ahc->scb_data->scbindex[scb->hscb->tag] = scb;
+}
+
+/*
+ * Tell the sequencer about a new transaction to execute.