need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)
explicitely by a plain integer array
the length in now known to all relevant parties, so this avoids
duplication of information, and we can allocate that thing in
drivers without hacks
- disk_unbusy() gets a new parameter to tell the IO direction.
- struct disk_sysctl gets 4 new members for read/write bytes/transfers.
when processing hw.diskstats, add the read&write bytes/transfers for
the old combined stats to attempt to keep backwards compatibility.
unfortunately, due to multiple bugs, this will cause new kernels and old
vmstat/iostat/systat programs to fail. however, the next time this is
change it will not fail again.
this is just the kernel portion.
flag to clear, even when the COMMAND COMPLETE interrupt already did happen,
otherwise we get ATTENTION ERROR for next command if it happens soon
enough; this fixes the reliability problems introduced by previous change
some other cleanup & simlify of edc_cmd_wait()/edc_run_cmd(), the 'secs'
is just a hint used in !poll case only
add some comments
move status_block[] back to edc_mca_softc, to save stack memory
make #ifdef DEBUG #ifdef EDC_DEBUG and g/c some obsolete debug stuff
make some EAGAINs EIOs
edc_intr(): wakeup the waiter for any command, not just READ/WRITE DATA
the MCA DMA controller access. This also means we gain >16MB RAM support.
While here, overhaul the driver to saner state, especially:
* simplify and clean the attach code a lot, and support the 'drive'
locator
* pass proper dev_t to readdisklabel() - formerly, the passed value was
completely broken (used incorrect major and wrong minor), but worked
by accident
* worker thread is now spawned per controller, rather than per-drive;
i/o cannot be done concurrently by different drivers, only one
i/o can be pending at any time
* simplify the command queue code, just sleep appropriately when
!poll case, g/c 'async' code formerly needed, move the bio code
from ed_mca.c to edc_mca.c:edc_bio()
* put all string arrays used by edc_dump_status_block() within #ifdef EDC_DEBUG,
and use numbers instead if it's not defined; this cuts object size by 5KB
* other misc cleanups
and for initial autoconf probes; the latter eliminates need for
deferred configuration (and makes dmesg a bit nicer).
g/c EDF_IODONE flag - protect against interrupt by calling tsleep()
at splbio in worker thread
g/c unneeded stuff, improve some autoconf messages
to be cleared always in edmcadone(), otherwise if there is a write
via bounce buffer followed by read directly to buf, the read operation
would return trashed data (the buf data would get overwritten
by contents of bounce buffer in edmcadone()).
Reset b_resid as necessary when the i/o is done, too.
g/c some unneeded stuff, use lockmgr()-style locking in ed_[un]lock(),
better avoid some deadlocks
These changes make the driver quite a bit more stable. It's actually
reliable enough to be possible to newfs the drive and use it for
read/write filesystem now.
