mutex releases to not require flags for the cases when preemption is
not allowed:
The purpose of the MTX_NOSWITCH and SWI_NOSWITCH flags is to prevent
switching to a higher priority thread on mutex releease and swi schedule,
respectively when that switch is not safe. Now that the critical section
API maintains a per-thread nesting count, the kernel can easily check
whether or not it should switch without relying on flags from the
programmer. This fixes a few bugs in that all current callers of
swi_sched() used SWI_NOSWITCH, when in fact, only the ones called from
fast interrupt handlers and the swi_sched of softclock needed this flag.
Note that to ensure that swi_sched()'s in clock and fast interrupt
handlers do not switch, these handlers have to be explicitly wrapped
in critical_enter/exit pairs. Presently, just wrapping the handlers is
sufficient, but in the future with the fully preemptive kernel, the
interrupt must be EOI'd before critical_exit() is called. (critical_exit()
can switch due to a deferred preemption in a fully preemptive kernel.)
I've tested the changes to the interrupt code on i386 and alpha. I have
not tested ia64, but the interrupt code is almost identical to the alpha
code, so I expect it will work fine. PowerPC and ARM do not yet have
interrupt code in the tree so they shouldn't be broken. Sparc64 is
broken, but that's been ok'd by jake and tmm who will be fixing the
interrupt code for sparc64 shortly.
Reviewed by: peter
Tested on: i386, alpha
- The MD functions critical_enter/exit are renamed to start with a cpu_
prefix.
- MI wrapper functions critical_enter/exit maintain a per-thread nesting
count and a per-thread critical section saved state set when entering
a critical section while at nesting level 0 and restored when exiting
to nesting level 0. This moves the saved state out of spin mutexes so
that interlocking spin mutexes works properly.
- Most low-level MD code that used critical_enter/exit now use
cpu_critical_enter/exit. MI code such as device drivers and spin
mutexes use the MI wrappers. Note that since the MI wrappers store
the state in the current thread, they do not have any return values or
arguments.
- mtx_intr_enable() is replaced with a constant CRITICAL_FORK which is
assigned to curthread->td_savecrit during fork_exit().
Tested on: i386, alpha
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
Some things needed bits of <i386/include/lock.h> - cy.c now has its
own (only) copy of the COM_(UN)LOCK() macros, and IMASK_(UN)LOCK()
has been moved to <i386/include/apic.h> (AKA <machine/apic.h>).
Reviewed by: jhb
incompletely converting simplelocks to mutexes (COM_LOCK() is supposed
to hide the SMP locking internals, but it now depends on mutex interfaces
being visible).
<sys/proc.h> to <sys/systm.h>.
Correctly document the #includes needed in the manpage.
Add one now needed #include of <sys/systm.h>.
Remove the consequent 48 unused #includes of <sys/proc.h>.
type of software interrupt. Roughly, what used to be a bit in spending
now maps to a swi thread. Each thread can have multiple handlers, just
like a hardware interrupt thread.
- Instead of using a bitmask of pending interrupts, we schedule the specific
software interrupt thread to run, so spending, NSWI, and the shandlers
array are no longer needed. We can now have an arbitrary number of
software interrupt threads. When you register a software interrupt
thread via sinthand_add(), you get back a struct intrhand that you pass
to sched_swi() when you wish to schedule your swi thread to run.
- Convert the name of 'struct intrec' to 'struct intrhand' as it is a bit
more intuitive. Also, prefix all the members of struct intrhand with
'ih_'.
- Make swi_net() a MI function since there is now no point in it being
MD.
Submitted by: cp
include:
* Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The
alpha port is still in transition and currently uses both.)
* Per-CPU idle processes.
* Interrupts are run in their own separate kernel threads and can be
preempted (i386 only).
Partially contributed by: BSDi (BSD/OS)
Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
isa_device->id_ri_flags and RI_FAST were not implemented and did nothing.
The two drivers that were mistakenly thinking this was working were
cy.c and loran.c - these should be converted to newbus.
GC (garbage collect) isa_device->id_alive
GC userconfig.c references to isa_device->id_scsiid (!).
have been there in the first place. A GENERIC kernel shrinks almost 1k.
Add a slightly different safetybelt under nostop for tty drivers.
Add some missing FreeBSD tags
fields in struct cdevsw:
d_stop moved to struct tty.
d_reset already unused.
d_devtotty linkage now provided by dev_t->si_tty.
These fields will be removed from struct cdevsw together with
d_params and d_maxio Real Soon Now.
The changes in this patch consist of:
initialize dev->si_tty in *_open()
initialize tty->t_stop
remove devtotty functions
rename ttpoll to ttypoll
a few adjustments to these changes in the generic code
a bump of __FreeBSD_version
add a couple of FreeBSD tags
Diskslice/label code not yet handled.
Vinum, i4b, alpha, pc98 not dealt with (left to respective Maintainers)
Add the correct hook for devfs to kern_conf.c
The net result of this excercise is that a lot less files depends on DEVFS,
and devtoname() gets more sensible output in many cases.
A few drivers had minor additional cleanups performed relating to cdevsw
registration.
A few drivers don't register a cdevsw{} anymore, but only use make_dev().
The cdevsw_add() function now finds the major number(s) in the
struct cdevsw passed to it. cdevsw_add_generic() is no longer
needed, cdevsw_add() does the same thing.
cdevsw_add() will print an message if the d_maj field looks bogus.
Remove nblkdev and nchrdev variables. Most places they were used
bogusly. Instead check a dev_t for validity by seeing if devsw()
or bdevsw() returns NULL.
Move bdevsw() and devsw() functions to kern/kern_conf.c
Bump __FreeBSD_version to 400006
This commit removes:
72 bogus makedev() calls
26 bogus SYSINIT functions
if_xe.c bogusly accessed cdevsw[], author/maintainer please fix.
I4b and vinum not changed. Patches emailed to authors. LINT
probably broken until they catch up.
Reformat and initialize correctly all "struct cdevsw".
Initialize the d_maj and d_bmaj fields.
The d_reset field was not removed, although it is never used.
I used a program to do most of this, so all the files now use the
same consistent format. Please keep it that way.
Vinum and i4b not modified, patches emailed to respective authors.
disable_intr() does non-recursive locking in the SMP case. This should
fix cy-driver-related panics when SMP is configured.
Broken in: rev.1.73 (3.1 and -current)
#define COMPAT_PCI_DRIVER(name,data) DATA_SET(pcidevice_set,data)
.. to 2.2.x and 3.x if people think it's worth it. Driver writers can do
this if it's not defined. (The reason for this is that I'm trying to
progressively eliminate use of linker_sets where it hurts modularity and
runtime load capability, and these DATA_SET's keep getting in the way.)
1:
s/suser/suser_xxx/
2:
Add new function: suser(struct proc *), prototyped in <sys/proc.h>.
3:
s/suser_xxx(\([a-zA-Z0-9_]*\)->p_ucred, \&\1->p_acflag)/suser(\1)/
The remaining suser_xxx() calls will be scrutinized and dealt with
later.
There may be some unneeded #include <sys/cred.h>, but they are left
as an exercise for Bruce.
More changes to the suser() API will come along with the "jail" code.
if option CY_PCI_FASTINTR is configured and mapping the irq to a
fastintr is possible. Unfortunately, this has to be optional because
pci_map_int_right() doesn't handle the INTR_EXCL flag right --
INTR_EXCL is honoured even if the interrupt needs to be non-exclusive
for other devices to work.
register for the PLX id). Merge the vendor's modification of the 2.2.*
release version into -current for reference. Will be cleaned up in next
commit.
Obtained from: ftp://ftp.cyclades.com/pub/cyclades/cyclom-y/freebsd/3.0/cyy30.tar.gz
in cyopen() were done in a different order than in sioopen(), partly
to (ab)use a side effect of comparam() and partly because I didn't
understand what the reset was doing (it flushes the fifos). This
turned out to be more than a cosmetic problem. Flushing the fifos
quite late is good for discarding input that arrived while the line
state was being initialized, and in the cy driver it also seems to
reduce a problem with input that arrived long ago during the previous
close (the UART loses sync too easily and for too long).
The optimisation of only waiting before issuing new commands is
obviously invalid in general and it caused many errors in NIST-PCTS.
I think the errors were mostly for characters sent with the wrong
parity, etc., after a half complete tcsetattr().
Use microtime() instead of a magic loop count to limit the wait.
The wait is a busy-wait :-( and normally takes about 500 usec.
almost works properly. Unfortunately, there is no way to flush
the rx fifo without resetting the channel, which also flushes the
tx fifo. We avoid resetting even when both fifos need to be flushed,
since resetting seems to cause the rx to lose sync if it is done
while data is arriving.
Reminded by: NIST-PCTS
hardware is interrupt-driven to a fault and sending a BREAK requires
mode switching. Always running in the BREAK-capable mode as in PR 8318
would double the overhead for sending \0's.
Reminded by: PR 8318
is completely empty. There is an interrupt for output completion. It
is painful to use, but polling method used in the corresponding fix in
sio.c (rev.1.152) can't be used because there is no status bit for
transmitter-empty. Now ttywait() works right.
Reminded by: NIST-PCTS
Don't call timeout() for DTR wakeup if the relevant timeout is already
active. This fixes "timeout table full" panics when sufficiently many
cyopen()s are interrupted while they are sleeping waiting for the
timeout to expire.
were half of their physical offsets for ISA and 1/4 of their physical
offsets for PCI, while all other Cyclades offsets were physical/1 for
ISA and physical/2 for PCI. Logically wrong macros were used to scale
CY16_RESET and CY_CLEAR_INTR to the correct physical offsets.
Fixed some style bugs (mostly long lines).
interrupt handlers. Instead, load and use it atomically as necessary.
This reduces mode switching overhead for "polled" mode interrupt handling
from 5 i/o's to 3 (per service type, per port) so that polled mode is only
slightly more inefficient than "interrupt" mode.
for the Lite2 fix for always returning EIO in dead_read().
Cleaned up the cdevswitch initializers for all tty drivers.
Removed explicit calls to ttsetwater() from all (tty) drivers. ttsetwater()
is now called centrally for opens, not just for parameter changes.
for 1 second's worth of input) and larger tty output buffers. The
interrupt-level buffers are still too small for speeds above 115200
bps (only a little too small for 230400 bps if RTS flow control is
enabled).
Don't call ttsetwater() explicitly in open(). It is now called for
the TTYDISC l_open() and should be static.
Don't attempt to register the cdevsw more than once.
of invariants to cyattach().
Fixed minor bugs:
- cyparam() returned without restoring the ipl in the error cases. This
was harmless because cyparam() is always called at spltty().
- one check for "rev. J or higher" actually checked for precisely rev. J.
swapped RTS/DTR). Merge the vendor's modification of the 2.2.6-release
version into -current for reference. Will be cleaned up in next commit.
Obtained from: ftp://ftp.cyclades.com/pub/cyclades/cyclom-y/freebsd/2.2.6/cyy226.tar.gz
instead of at compile time using ifdefs.
Use _swi_null instead of dummycamisr. CAM and dpt should call
register_swi() instead of hacking on ihandlers[] directly.
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
The differences Terrys patch and this patch are:
* Remove a lot of un-needed comments.
* Don't put l_hotchar at the front of stuct linesw, there is no need to.
* Use the #defines for the hotchar in the SLIP and PPP line disciplines
This introduce an xxxFS_BOOT for each of the rootable filesystems.
(Presently not required, but encouraged to allow a smooth move of option *FS
to opt_dontuse.h later.)
LFS is temporarily disabled, and will be re-enabled tomorrow.
actually offsets, they are offsets scaled by dividing by 2^cy_align.
I use different values for cy_align since the -current values are
unnaturally scaled, so I need different offsets, and the wrong
offsets got committed.
Reported by: nnd@itfs.nsk.su (N.Dudorov)
Add a simplelock to deal with disable_intr()/enable_intr() as used in UP kernel.
UP kernel expects that this is enough to guarantee exclusive access to
regions of code bracketed by these 2 functions.
Add a simplelock to bracket clock accesses in clock.c: clock_lock.
Help from: Bruce Evans <bde@zeta.org.au>
I have no way of testing this one, first SMP/cy user please let me know...
It is my belief that sio and cy are the only FAST_INTR() ISRs. If this
is a bad assumption please educate me.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
