---
This list of changes is in approximately chronological order (oldest first).
o Many cosmetic changes - renamed comintr1 -> siointr1, moved
things around and fixed whitespace.
o Reduced SLIP latency (FRAME_END hack) from 20-30 ms to 16 ms
at 115200 bps (you won't notice the average 10 ms improvement
on slow lines). ppp seems to use only counted transfers so
there's no similar hack available. It's too hard for the
driver to know the count.
o Temporary #ifdefs for new and old interrupt handling
(OLD_INTERRUPT_HANDLING decided by setsofttty() not being
externally defined.
o Don't test for the IIR_NOPEND bit being set - test for the
non-fifo part of the iir equalling it like the docs say to.
States with other IIR_NOPEND set in combination with the
other iir bits are undefined. The docs may be stupid - the
old test would not have broken when the fifo bits were
introduced.
o Noted more problems with DTR wait.
o Rewrote console stuff. Still some initialization and state
preservation problems. Same for kgdb stuff. The driver
doesn't do anything about the console close bug. It needs
to be fixed entirely in i386/cons.c. I like chmr's version
where the the console driver revectors the device open and
close routines.
o Temporary (?) #ifdefs for references to tty buffers.
o Noted further things to do in (2 comments about 3 places) for
phk's change to not touch RTS unless it is being used for flow
control.
o Temporary #ifdefs for timestamp handling. It needs fixing.
The microtime() call breaks the first rule of writing fast
interrupt handlers: NO calls to functions that might do slow
and bad things. microtime() enables interrupts. This turns
out to be only moderately harmful. Also, I want the timestamp
copy outside of the normal interrupt handler.
o Don't init com->tp early for the !DONT_MALLOC_TTYS case -
both sides are NULL.
o Worry about com->tp == NULL in siopoll. I don't see how you
survived the (incc <= 0 || !(tp->state & TS_ISOPEN)) test.
Perhaps early sttys or comcontrols set up the tp's for _all_
the ports before this code is reached.
list of changes, I've made the following additional changes:
1) i386/include/ipl.h renamed to spl.h as the name conflicts with the
file of the same name in i386/isa/ipl.h.
2) changed all use of *mask (i.e. netmask, biomask, ttymask, etc) to
*_imask (net_imask, etc).
3) changed vestige of splnet use in if_is to splimp.
4) got rid of "impmask" completely (Bruce had gotten rid of netmask),
and are now using net_imask instead.
5) dozens of minor cruft to glue in Bruce's changes.
These require changes I made to config(8) as well, and thus it must
be rebuilt.
-DG
from Bruce Evans:
sio:
o No diff is supplied. Remove the define of setsofttty(). I hope
that is enough.
*.s:
o i386/isa/debug.h no longer exists. The event counters became too
much trouble to maintain. All function call entry and exception
entry counters can be recovered by using profiling kernel (the new
profiling supports all entry points; however, it is too slow to
leave enabled all the time; it also). Only BDBTRAP() from debug.h
is now used. That is moved to exception.s. It might be worth
preserving SHOW_BITS() and calling it from _mcount() (if enabled).
o T_ASTFLT is now only set just before calling trap().
o All exception handlers set SWI_AST_MASK in cpl as soon as possible
after entry and arrange for _doreti to restore it atomically with
exiting. It is not possible to set it atomically with entering
the kernel, so it must be checked against the user mode bits in
the trap frame before committing to using it. There is no place
to store the old value of cpl for syscalls or traps, so there are
some complications restoring it.
Profiling stuff (mostly in *.s):
o Changes to kern/subr_mcount.c, gcc and gprof are not supplied yet.
o All interesting labels `foo' are renamed `_foo' and all
uninteresting labels `_bar' are renamed `bar'. A small change
to gprof allows ignoring labels not starting with underscores.
o MCOUNT_LABEL() is to provide names for counters for times spent
in exception handlers.
o FAKE_MCOUNT() is a version of MCOUNT() suitable for exception
handlers. Its arg is the pc where the exception occurred. The
new mcount() pretends that this was a call from that pc to a
suitable MCOUNT_LABEL().
o MEXITCOUNT is to turn off any timer started by MCOUNT().
/usr/src/sys/i386/i386/exception.s:
o The non-BDB BPTTRAP() macros were doing a sti even when interrupts
were disabled when the trap occurred. The sti (fixed) sti is
actually a no-op unless you have my changes to machdep.c that make
the debugger trap gates interrupt gates, but fixing that would
make the ifdefs messier. ddb seems to be unharmed by both
interrupts always disabled and always enabled (I had the branch in
the fix back to front for some time :-().
o There is no known pushal bug.
o tf_err can be left as garbage for syscalls.
/usr/src/sys/i386/i386/locore.s:
o Fix and update BDE_DEBUGGER support.
o ENTRY(btext) before initialization was dangerous.
o Warm boot shot was longer than intended.
/usr/src/sys/i386/i386/machdep.c:
o DON'T APPLY ALL OF THIS DIFF. It's what I'm using, but may require
other changes.
Use the following:
o Remove aston() and setsoftclock().
Maybe use the following:
o No netisr.h.
o Spelling fix.
o Delay to read the Rebooting message.
o Fix for vm system unmapping a reduced area of memory
after bounds_check_with_label() reduces the size of
a physical i/o for a partition boundary. A similar
fix is required in kern_physio.c.
o Correct use of __CONCAT. It never worked here for non-
ANSI cpp's. Is it time to drop support for non-ANSI?
o gdt_segs init. 0xffffffffUL is bogus because ssd_limit
is not 32 bits. The replacement may have the same
value :-), but is more natural.
o physmem was one page too low. Confusing variable names.
Don't use the following:
o Better numbers of buffers. Each 8K page requires up to
16 buffer headers. On my system, this results in 5576
buffers containing [up to] 2854912 bytes of memory.
The usual allocation of about 384 buffers only holds
192K of disk if you use it on an fs with a block size
of 512.
o gdt changes for bdb.
o *TGT -> *IDT changes for bdb.
o #ifdefed changes for bdb.
/usr/src/sys/i386/i386/microtime.s:
o Use the correct asm macros. I think asm.h was copied from Mach
just for microtime and isn't used now. It certainly doesn't
belong in <sys>. Various macros are also duplicated in
sys/i386/boot.h and libc/i386/*.h.
o Don't switch to and from the IRR; it is guaranteed to be selected
(default after ICU init and explicitly selected in isa.c too, and
never changed until the old microtime clobbered it).
/usr/src/sys/i386/i386/support.s:
o Non-essential changes (none related to spls or profiling).
o Removed slow loads of %gs again. The LDT support may require
not relying on %gs, but loading it is not the way to fix it!
Some places (copyin ...) forgot to load it. Loading it clobbers
the user %gs. trap() still loads it after certain types of
faults so that fuword() etc can rely on it without loading it
explicitly. Exception handlers don't restore it. If we want
to preserve the user %gs, then the fastest method is to not
touch it except for context switches. Comparing with
VM_MAXUSER_ADDRESS and branching takes only 2 or 4 cycles on
a 486, while loading %gs takes 9 cycles and using it takes
another.
o Fixed a signed branch to unsigned.
/usr/src/sys/i386/i386/swtch.s:
o Move spl0() outside of idle loop.
o Remove cli/sti from idle loop. sw1 does a cli, and in the
unlikely event of an interrupt occurring and whichqs becoming
zero, sw1 will just jump back to _idle.
o There's no spl0() function in asm any more, so use splz().
o swtch() doesn't need to be superaligned, at least with the
new mcounting.
o Fixed a signed branch to unsigned.
o Removed astoff().
/usr/src/sys/i386/i386/trap.c:
o The decentralized extern decls were inconsistent, of course.
o Fixed typo MATH_EMULTATE in comments. */
o Removed unused variables.
o Old netmask is now impmask; print it instead. Perhaps we
should print some of the new masks.
o BTW, trap() should not print anything for normal debugger
traps.
/usr/src/sys/i386/include/asmacros.h:
o DON'T APPLY ALL OF THIS DIFF. Just use some of the null macros
as necessary.
/usr/src/sys/i386/include/cpu.h:
o CLKF_BASEPRI() changes since cpl == SWI_AST_MASK is now normal
while the kernel is running.
o Don't use var++ to set boolean variables. It fails after a mere
4G times :-) and is slower than storing a constant on [3-4]86s.
/usr/src/sys/i386/include/cpufunc.h:
o DON'T APPLY ALL OF THIS DIFF. You need mainly the include of
<machine/ipl.h>. Unfortunately, <machine/ipl.h> is needed by
almost everything for the inlines.
/usr/src/sys/i386/include/ipl.h:
o New file. Defines spl inlines and SWI macros and declares most
variables related to hard and soft interrupt masks.
/usr/src/sys/i386/isa/icu.h:
o Moved definitions to <machine/ipl.h>
/usr/src/sys/i386/isa/icu.s:
o Software interrupts (SWIs) and delayed hardware interrupts (HWIs)
are now handled uniformally, and dispatching them from splx() is
more like dispatching them from _doreti. The dispatcher is
essentially *(handler[ffs(ipending & ~cpl)]().
o More care (not quite enough) is taken to avoid unbounded nesting
of interrupts.
o The interface to softclock() is changed so that a trap frame is
not required.
o Fast interrupt handlers are now handled more uniformally.
Configuration is still too early (new handlers would require
bits in <machine/ipl.h> and functions to vector.s).
o splnnn() and splx() are no longer here; they are inline functions
(could be macros for other compilers). splz() is the nontrivial
part of the old splx().
/usr/src/sys/i386/isa/ipl.h
o New file. Supposed to have only bus-dependent stuff. Perhaps
the h/w masks should be declared here.
/usr/src/sys/i386/isa/isa.c:
o DON'T APPLY ALL OF THIS DIFF. You need only things involving
*mask and *MASK and comments about them. netmask is now a pure
software mask. It works like the softclock mask.
/usr/src/sys/i386/isa/vector.s:
o Reorganize AUTO_EOI* macros.
o Option FAST_INTR_HANDLER_USERS_ES for people who don't trust
fastintr handlers.
o fastintr handlers need to metamorphose into ordinary interrupt
handlers if their SWI bit has become set. Previously, sio had
unintended latency for handling output completions and input
of SLIP framing characters because this was not done.
/usr/src/sys/net/netisr.h:
o The machine-dependent stuff is now imported from <machine/ipl.h>.
/usr/src/sys/sys/systm.h
o DON'T APPLY ALL OF THIS DIFF. You need mainly the different
splx() prototype. The spl*() prototypes are duplicated as
inlines in <machine/ipl.h> but they need to be duplicated here
in case there are no inlines. I sent systm.h and cpufunc.h
to Garrett. We agree that spl0 should be replaced by splnone
and not the other way around like I've done.
/usr/src/sys/kern/kern_clock.c
o splsoftclock() now lowers cpl so the direct call to softclock()
works as intended.
o softclock() interface changed to avoid passing the whole frame
(some machines may need another change for profile_tick()).
o profiling renamed _profiling to avoid ANSI namespace pollution.
(I had to improve the mcount() interface and may as well fix it.)
The GUPROF variant doesn't actually reference profiling here,
but the 'U' in GUPROF should mean to select the microtimer
mcount() and not change the interface.
Example:
Application use port cua01
Getty open ttyd1 (allocates rawq,outq,etc) and waits while application
done
Application quits, sioclose issued, ttyfree issued (getty calls revoke)
Getty awakes and goes to panic into initrb (NULL rawq)
now HUPCL set only in bidir case for callin lines
(this prevents set HUPCL on mouse)
comhardclose:
in addition to HUPCL case now DTR dropped for bidir case
if line was active in and no carrier present now.
(this prevents DTR sleep on mouse)
This inetrface should be used from now on.
pseudo device pty xx still keeps its meaning: a maximum of
xx ptys is allowed.
A ringbuffer is now 2040 bytes long, per Garrett Wollman's request.
The changes are inspired by the way NetBSD did it (thanks for that!),
though I made it slihghtly different, including the interface so
at least 75% of the allocated space is deallocated when the tty is
closed.
Note further that it is easy to modify the ringbuffer length runtime.
This will have to wait untill some later date...
-Guido
netmask or impmask.
2) Fixes from Bruce:
o Changed name of schedsoftcom() to setsofttty() to match
setsoftclock()
o Bool_t isn't used.
o tx_fifo_size is 1 for chips without fifos, 16 for 16550's, to
help to output more efficiently for 16550's (LSR_TXRDY means
that the fifo is empty, not that it has space for one char).
o Changed name of softsio1() to siopoll() and merged compoll()
into siopoll().
o The probe forgot to clear com_mcr after it failed. This is
harmful for 4 single serial ports on 2 interrupts. It makes
partial misconfigurations worse.
o Don't bother initializing static variables that are 0 (bidir
stuff).
o Only initialize t_oflag to TTYDEF_OFLAG if unit == COMCONSOLE,
not if COMCONSOLE is defined.
o Don't call siointr() from comparam() if there is no output in
progress. For the call from sioopen(), there's no output in
progress, and siointr() often saw silo overflows for stale
input because it was called before sioopen() discarded the
input.
o Let ttselect() do the work for select(), so that the fixes for
ttselect() don't have to be duplicated in zillions of drivers.
file override to disable fifo on 16550s:
I bought a board with two 16550's, but one of those ports has a mouse
on it. The sio driver always enables the fifo, which is a bad thing
for mice and X. The mouse is jerky and hard to use. The simple thing
is be to treat one of the ports as a non-fifo'ed UART, and I use the
flags option in my config file.
So, my config file has:
device sio0 at isa? port "IO_COM1" tty irq 4 flags 0x2 vector siointr
device sio1 at isa? port "IO_COM2" tty irq 3 vector siointr
(patch deleted)
Choose older MULTIPORT version, because lastest bde version
not worked.
Don't force HUPCL for bidirectional case.
From bde:
Use bit (1 << (16 + 4)) in schedsoftcom() to avoid clash with
non-serial h/w on IRQ4.
Allow FIFO_TRIGGER in config.
Clear com->mcr_image when clearing mcr for init of 4port. The
usual value MCR_IENABLE should have broken 4ports unless
something happened to clear it later.
Turn off interrupts as well as DTR after an error waiting for
carrier (bidir dialin case).
Drain fifo more carefully.
Don't hang up if debugging.
Rearrange siointr() -> siointr1() for multiport case for speed,
lower latency and clarity.
Use suser() to check perms.
Provide missing splx() after failed perms checks.
c_ispeed == 0 means c_ispeed = c_ospeed (POSIX).
Set parameters (except speed) for c_ospeed == 0 as well as
hanging up.
Better initialization for console (fifo stuff...).
Misc. cleanups.
Fix dead hang if modem power is off.
added to probe.
2) Force CLOCAL=on for outgoing ports and CLOCAL=off for
incoming ports into open in bidirectional case.
3) Add DELAY after writing to com_ier for fifo drain into probe.
That is because TIOCMGET was broken. Yes...this is known for some time
and no, we (Bruce and me) never posted it. Why? Simply because we choose
to post fixes when we fixed most of the bugs.
Anyway..now that the slip problems are coming, here is a fix for
correct TIOCMGET behaviour.
-Guido
Note: this should be tested first (Rich?). Tested by rgrimes
Subject: Re: Some small errors in GAMMA
4. Move printf("\n"); at line 491 in "/sys/i386/isa/sio.c" to after
COM_MULTIPORT block at line 512.
From rgrimes:
The above would cause the word (multiport) with out a new line to
appear after the uart type message if you had COM_MULTIPORT enabled.
way of doing things. There still remain several drivers that need to
be updated. Also added a compile-time option to pccons to switch the
control and caps-lock keys (REVERSE_CAPS_CTRL) - added for my personal
sanity.
