better. There is a related I/O error flag which we don't support in
the kernel but must support here. (Support for bits that we don't
understand here is mostly automatic by fail-safeness, but checkdirty()
has fail-unsafeness.) There are some reserved and don't-care bits
that weren't fully documented and aren't always masked properly. The
comment about the bits in readfat() will be removed when the masking
is fixed.
Submitted by: rnordier
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.
Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64
TIOCMSET before FreeBSD existed and have never been implemented by any
FreeBSD serial driver (not even as aliases).
Moved the TIOCM bit definitions to be with TIOCMGET.
Added more comments gaps between ioctl numbers. There are now a large
number of conflicts with ppp, slip, tap and tun ioctls (especially ppp
ones) from closing gaps that weren't there. This mainly breaks decoding
of ioctl numbers in kdump, but there are some serious conflicts where
the interpretation of a tty ioctl depends on the line discipline.
aic79xx.seq:
Convert the COMPLETE_DMA_SCB list to an "stailq". This allows us to
safely keep the SCB that is currently being DMA'ed back the host on
the head of the list while processing completions off of the bus. The
newly completed SCBs are appended to the tail of the queue. In the
past, we just dequeued the SCB that was in flight from the list, but
this could result in a lost completion should the host perform certain
types of error recovery that must cancel all in-flight SCB DMA operations.
Switch from using a 16bit completion entry, holding just the tag and the
completion valid bit, to a 64bit completion entry that also contains a
"status packet valid" indicator. This solves two problems:
o The SCB DMA engine on at least Rev B. silicon does not properly deal
with a PCI disconnect that occurs at a non-64bit aligned offset in the
chips "source buffer". When the transfer is resumed, the DMA engine
continues at the correct offset, but may wrap to the head of the buffer
causing duplicate completions to be reported to the host. By using a
completion buffer in host memory that is 64bit aligned and using 64bit
completion entries, such disconnects should only occur at aligned addresses.
This assumes that the host bridge will only disconnect on cache-line
boundaries and that cache-lines are multpiles of 64bits.
o By embedding the status information in the completion entry we can avoid
an extra memory reference to the HSCB for commands that complete without
error.
Use the comparison of a "host freeze count" and a "sequencer freeze count"
to allow the host to process most SCBs that complete with non-zero status
without having to clear critical sections. Instead the host can just pause the
sequencer, performs any necessary cleanup in the waiting for selection list,
increments its freeze count on the controller, and unpauses. This is only
possible because the sequencer defers completions of SCBs with bad status
until after all pending selections have completed. The sequencer then avoids
referencing any data structures the host may touch during completion of the
SCB until the freeze counts match.
aic79xx.c:
Change the strategy for allocating our sentinal HSCB for the QINFIFO. In
the past, this allocation was tacked onto the QOUTFIFO allocation. Now that
the qoutfifo has grown to accomodate larger completion entries, the old
approach will result in a 64byte allocation that costs an extra page of
coherent memory. We now do this extra allocation via ahd_alloc_scbs()
where the "unused space" can be used to allocate "normal" HSCBs.
In our packetized busfree handler, use the ENSELO bit to differentiate
between packetized and non-packetized unexpected busfree events that
occur just after selection, but before the sequencer has had the oportunity
to service the selection.
When cleaning out the waiting for selection list, use the SCSI mode
instead of the command channel mode. The SCB pointer in the command
channel mode may be referenced by the SCB dma engine even while the
sequencer is paused, whereas the SCSI mode SCB pointer is only accessed
by the sequencer.
Print the "complete on qfreeze" sequencer SCB completion list in
ahd_dump_card_state(). This list holds all SCB completions that are deferred
until a pending select-out qfreeze event has taken effect.
aic79xx.h:
Add definitions and structures to handle the new SCB completion scheme.
Add a controller flag that indicates if the controller is in HostRAID
mode.
aic79xx.reg:
Remove macros used for toggling from one data fifo mode to the other.
They have not been in use for some time.
Add scratch ram fields for our new qfreeze count scheme, converting
the complete dma list into an "stailq", and providing for the "complete
on qfreeze" SCB completion list. Some other fields were moved to retain
proper field alignment (alignment >= field size in bytes).
aic79xx.seq:
Add code to our idle loop to:
o Process deferred completions once a qfreeze event has taken full
effect.
o Thaw the queue once the sequencer and host qfreeze counts match.
Generate 64bit completion entries passing the SCB_SGPTR field as the
"good status" indicator. The first bit in this field is only set if
we have a valid status packet to send to the host.
Convert the COMPLETE_DMA_SCB list to an "stailq".
When using "setjmp" to register an idle loop handler, do not combine
the "ret" with the block move to pop the stack address in the same
instruction. At least on the A, this results in a return to the setjmp
caller, not to the new address at the top of the stack. Since we want
the latter (we want the newly registered handler to only be invoked from
the idle loop), we must use a separate ret instruction.
Add a few missing critical sections.
Close a race condition that can occur on Rev A. silicon. If both FIFOs
happen to be allocated before the sequencer has a chance to service the
FIFO that was allocated first, we must take special care to service the
FIFO that is not active on the SCSI bus first. This guarantees that a
FIFO will be freed to handle any snapshot requests for the FIFO that is
still on the bus. Chosing the incorrect FIFO will result in deadlock.
Update comments.
aic79xx_inline.h
Correct the offset calculation for the syncing of our qoutfifo.
Update ahd_check_cmdcmpltqueues() for the larger completion entries.
aic79xx_pci.c:
Attach to HostRAID controllers by default. In the future I may add a
sysctl to modify the behavior, but since FreeBSD does not have any
HostRAID drivers, failing to attach just results in more email and
bug reports for the author.
MFC After: 1week
CFLAGS in all cases, but POSIX requires a default of -O. Adding
-pipe unconditionally still is still broken for non-gcc compilers
in the non-POSIX case.
namespace pollution in other headers. <sys/types.h> is now the only
prerequisite for <sys/sx.h>.
Fixed some style bugs:
- removed bogus LOCORE ifdef. Including this C header in assembler
sources is just nonsense.
- removed unused include of <sys/_mutex.h>. It finished rotting when
the mutex in struct sx became indirect in rev.1.15.
- removed most comments on #else and #endif's and cleaned up the others.
All were misindented...
- add an option for the output device in the hope that this can
be made non-blocking at some stage.
- define an alias for the disk device, required by dev/ofw/ofw_disk.c
- shift iobus to 0x9000000 so as not to clash with the OpenFirmware
entry point of 0x8000400 when address decoding.
- down-tone comments about the disk dev config :-)
using the direct-mapping of physmem to force PTE data structures
to be physically addressable so the interrupt-time real-mode
DSI trap handler could perform PTE spills. However, the memory
may have been > 256Mb, which would have caused a BAT spill and
double-interrupt.
The new trap code no longer handles PTE spills, so the requirement
that these pages be direct-mapped no longer applies. The irony is
UMA_MD_SMALL_ALLOC will return direct mappings for these structs :-)
- remove unused 601 and tlb exception code
- remove interrupt-time PTE spill code. The pmap code
will now take care of pinning kernel PTEs, and there
are no longer issues about physical mapping of PTE
data structures
- All segment registers are switched on kernel entry/exit,
allowing the kernel to have more virtual space and for
user virtual space to extend to 4G.
- The temporary register save area has been shifted from
unused exception vector space to the per-cpu data area.
This allows interrupts to be delivered to multiple CPUs
- ISI traps no longer spill to BAT tables. It is assumed
that all of kernel instruction memory is pinned.
- shift from 'ldmw/stmw' instructions to individual register
loads/stores when saving context. All PPC manuals indicate
this should be much faster.
- use '%r' for register names throughout.
TODO: need to test if DSI traps were the result of kernel stack
guard-page hits.
Reworked from: NetBSD
PS. There is a inconsistency in this manual page, because in
non-WITNESS case sx_assert(9) does not panics, it only prints
the warning. I haven't fixed this, because jhb@ is planing to
replace those printf()s with panic()s.
Reviewed by: jhb
Approved by: jhb, scottl (mentor)
