- newbus plumbing. Each atapicam bus is a child off of a parent ata channel
bus. This is somewhat of a hack, but allows the ata core to be completely
free of atapicam knowledge.
- No more global lists of softc's and no more groping around in internal ata
structures on each command.
- Giant-free operation of the completion handler.
- Per-bus mutex for protecting the busy list and synchronizing detach.
- Lots of streamlining and dead code elimination, better adherence to the
CAM locking protocol.
This feature still requires that the appropriate atapi-* driver be present
for each atapi device that you want to talk to (i.e. atapi-cd for cdroms).
It does work both compiled into the kernel and as a loadable module.
Reviewed by: thomas, sos
critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.
Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.
This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).
Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more
to see what features they may support before calling identify/probe/attach.
This is necessary because the ACPI 3.0 spec requires driver support be
advertised before running any methods. For now, the flags are as specified
in for the _PDC and _OSC methods but we can support private flags as needed.
Add an implementation of this for acpi_cpu. It checks all its children
(notably cpufreq drivers) and calls the _PDC method to report the results.
instances in a given devclass. This is useful for systems that want to
call code in driver static methods, similar to device_identify().
Reviewed by: dfr
MFC after: 2 weeks
one to become available for one second and then return ENFILE. We
can run out of vnodes, and there must be a hard limit because without
one we can quickly run out of KVA on x86. Presently the system can
deadlock if there are maxvnodes directories in the namecache. The
original 4.x BSD behavior was to return ENFILE if we reached the max,
but 4.x BSD did not have the vnlru proc so it was less profitable to
wait.
down. If we have dirty pages, the putpages routine will need to know
what the vnode's object is so that it may write out dirty pages.
Pointy hat: phk
Found by: obrien
in a devclass. All the other uses of maxunit are correct and this one was
safe since it checks the return value of devclass_get_device(), which would
always say that the highest unit device doesn't exist.
Reviewed by: dfr
MFC after: 3 days
on boot, force it to HIGH. This is needed for some systems which appear
to boot with a low acpi_throttle setting by default. Thanks to Christian
Brueffer for tracking this down on his system.
MFC after: 1 day
