This is a completely rewritten scsipi_xfer execution engine, and the
associated changes to HBA drivers. Overview of changes & features:
- All xfers are queued in the mid-layer, rather than doing so in an
ad-hoc fashion in individual adapter drivers.
- Adapter/channel resource management in the mid-layer, avoids even trying
to start running an xfer if the adapter/channel doesn't have the resources.
- Better communication between the mid-layer and the adapters.
- Asynchronous event notification mechanism from adapter to mid-layer and
peripherals.
- Better peripheral queue management: freeze/thaw, sorted requeueing during
recovery, etc.
- Clean separation of peripherals, adapters, and adapter channels (no more
scsipi_link).
- Kernel thread for each scsipi_channel makes error recovery much easier
(no more dealing with interrupt context when recovering from an error).
- Mid-layer support for tagged queueing: commands can have the tag type
set explicitly, tag IDs are allocated in the mid-layer (thus eliminating
the need to use buggy tag ID allocation schemes in many adapter drivers).
- support for QUEUE FULL and CHECK CONDITION status in mid-layer; the command
will be requeued, or a REQUEST SENSE will be sent as appropriate.
Just before the merge syssrc has been tagged with thorpej_scsipi_beforemerge
- run request sense command without disconnect
- don't restart the script before siop_scsicmd_end has been called if the
cmd didn't complete with good status.
- reserve slot 0 for request sense, to make sure it'll be sent first.
- move status handling in siop_scsicmd_end(), it's better than in siop_intr()
- define 2 internal SIOP status, for "no status reported by device" and
reset condition
- add a list of "urgent" command, to be executed before the list of command
queued the normal way; this is used for command which got aborted
by a QUEUE FULL and have to be requeued in order.
- Don't accept to send a Q_TAG message not immediatly folowing a IDENTIFY
Implement SCBUSACCEL ioctl.
Snapshot of work in progress on tagged queuing: we can send/receive
queue tag messages. Infrastructure to manage multiple commands per
devices not here yet.
Reset the scsi bus at attach time, to be sure all devices start in narrow/async
mode.
Defer sync/wide negotiation until after whe have a valid
xs->sc_link->device_softc, so that we can honnor the NOSYNC/NOWIDE quirks.
<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>
also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.
bouyer