Commit Graph

205 Commits

Author SHA1 Message Date
Jeff Roberson
6c47aaae12 - Add an integer argument to idle to indicate how likely we are to wake
from idle over the next tick.
 - Add a new MD routine, cpu_wake_idle() to wakeup idle threads who are
   suspended in cpu specific states.  This function can fail and cause the
   scheduler to fall back to another mechanism (ipi).
 - Implement support for mwait in cpu_idle() on i386/amd64 machines that
   support it.  mwait is a higher performance way to synchronize cpus
   as compared to hlt & ipis.
 - Allow selecting the idle routine by name via sysctl machdep.idle.  This
   replaces machdep.cpu_idle_hlt.  Only idle routines supported by the
   current machine are permitted.

Sponsored by:	Nokia
2008-04-25 05:18:50 +00:00
Poul-Henning Kamp
0051271e12 Make genclock standard on all platforms.
Thanks to: grehan & marcel for platform support on ia64 and ppc.
2008-04-21 10:09:55 +00:00
Jeff Roberson
9b33b154b5 - Add the interrupt vector number to intr_event_create so MI code can
lookup hard interrupt events by number.  Ignore the irq# for soft intrs.
 - Add support to cpuset for binding hardware interrupts.  This has the
   side effect of binding any ithread associated with the hard interrupt.
   As per restrictions imposed by MD code we can only bind interrupts to
   a single cpu presently.  Interrupts can be 'unbound' by binding them
   to all cpus.

Reviewed by:	jhb
Sponsored by:	Nokia
2008-04-11 03:26:41 +00:00
John Baldwin
1ee1b68792 Add a MI intr_event_handle() routine for the non-INTR_FILTER case. This
allows all the INTR_FILTER #ifdef's to be removed from the MD interrupt
code.
- Rename the intr_event 'eoi', 'disable', and 'enable' hooks to
  'post_filter', 'pre_ithread', and 'post_ithread' to be less x86-centric.
  Also, add a comment describe what the MI code expects them to do.
- On amd64, i386, and powerpc this is effectively a NOP.
- On arm, don't bother masking the interrupt unless the ithread is
  scheduled in the non-INTR_FILTER case to match what INTR_FILTER did.
  Also, don't bother unmasking the interrupt in the post_filter case if
  we never masked it.  The INTR_FILTER case had been doing this by having
  arm_unmask_irq for the post_filter (formerly 'eoi') hook.
- On ia64, stray interrupts are now masked for the non-INTR_FILTER case.
  They were already masked in the INTR_FILTER case.
- On sparc64, use the a NULL pre_ithread hook and use intr_enable_eoi() for
  both the 'post_filter' and 'post_ithread' hooks to match what the
  non-INTR_FILTER code did.
- On sun4v, retire the ithread wrapper hack by using an appropriate
  'post_ithread' hook instead (it's what 'post_ithread'/'enable' was
  designed to do even in 5.x).

Glanced at by:	piso
Reviewed by:	marius
Requested by:	marius [1], [5]
Tested on:	amd64, i386, arm, sparc64
2008-04-05 19:58:30 +00:00
Doug Rabson
fa9d9930ca Add kernel module support for nfslockd and krpc. Use the module system
to detect (or load) kernel NLM support in rpc.lockd. Remove the '-k'
option to rpc.lockd and make kernel NLM the default. A user can still
force the use of the old user NLM by building a kernel without NFSLOCKD
and/or removing the nfslockd.ko module.
2008-03-27 11:54:20 +00:00
John Birrell
e483943791 When building a kernel module, define MAXCPU the same as SMP so
that modules work with and without SMP.
2008-03-27 05:03:26 +00:00
Poul-Henning Kamp
8c0b6469bf Remove two variables which are handled MI now. 2008-03-26 20:28:52 +00:00
Poul-Henning Kamp
e465985885 The "free-lance" timer in the i8254 is only used for the speaker
these days, so de-generalize the acquire_timer/release_timer api
to just deal with speakers.

The new (optional) MD functions are:
	timer_spkr_acquire()
	timer_spkr_release()
and
	timer_spkr_setfreq()

the last of which configures the timer to generate a tone of a given
frequency, in Hz instead of 1/1193182th of seconds.

Drop entirely timer2 on pc98, it is not used anywhere at all.

Move sysbeep() to kern/tty_cons.c and use the timer_spkr*() if
they exist, and do nothing otherwise.

Remove prototypes and empty acquire-/release-timer() and sysbeep()
functions from the non-beeping archs.

This eliminate the need for the speaker driver to know about
i8254frequency at all.  In theory this makes the speaker driver MI,
contingent on the timer_spkr_*() functions existing but the driver
does not know this yet and still attaches to the ISA bus.

Syscons is more tricky, in one function, sc_tone(), it knows the hz
and things are just fine.

In the other function, sc_bell() it seems to get the period from
the KDMKTONE ioctl in terms if 1/1193182th second, so we hardcode
the 1193182 and leave it at that.  It's probably not important.

Change a few other sysbeep() uses which obviously knew that the
argument was in terms of i8254 frequency, and leave alone those
that look like people thought sysbeep() took frequency in hertz.

This eliminates the knowledge of i8254_freq from all but the actual
clock.c code and the prof_machdep.c on amd64 and i386, where I think
it would be smart to ask for help from the timecounters anyway [TBD].
2008-03-26 20:09:21 +00:00
Poul-Henning Kamp
b416a29043 Remove old sysctl stuff which is long gone in other arch's. 2008-03-26 13:03:51 +00:00
Pawel Jakub Dawidek
ab35440fa1 Oops. Use atomic_add_long() for atomic_fetchadd_long() (not atomic_add_int())
for sparc64 and sun4v.

Noticed by:	marius
2008-03-19 07:27:24 +00:00
John Baldwin
07f7fccaaf Catch up to intr_event_create() prototype change.
Pointy hat:	jhb
2008-03-18 13:31:45 +00:00
Pawel Jakub Dawidek
6eb4157ffc Implement atomic_fetchadd_long() for all architectures and document it.
Reviewed by:	attilio, jhb, jeff, kris (as a part of the uidinfo_waitfree.patch)
2008-03-16 21:20:50 +00:00
John Baldwin
eaf86d1678 Add preliminary support for binding interrupts to CPUs:
- Add a new intr_event method ie_assign_cpu() that is invoked when the MI
  code wishes to bind an interrupt source to an individual CPU.  The MD
  code may reject the binding with an error.  If an assign_cpu function
  is not provided, then the kernel assumes the platform does not support
  binding interrupts to CPUs and fails all requests to do so.
- Bind ithreads to CPUs on their next execution loop once an interrupt
  event is bound to a CPU.  Only shared ithreads are bound.  We currently
  leave private ithreads for drivers using filters + ithreads in the
  INTR_FILTER case unbound.
- A new intr_event_bind() routine is used to bind an interrupt event to
  a CPU.
- Implement binding on amd64 and i386 by way of the existing pic_assign_cpu
  PIC method.
- For x86, provide a 'intr_bind(IRQ, cpu)' wrapper routine that looks up
  an interrupt source and binds its interrupt event to the specified CPU.
  MI code can currently (ab)use this by doing:

	intr_bind(rman_get_start(irq_res), cpu);

  however, I plan to add a truly MI interface (probably a bus_bind_intr(9))
  where the implementation in the x86 nexus(4) driver would end up calling
  intr_bind() internally.

Requested by:	kmacy, gallatin, jeff
Tested on:	{amd64, i386} x {regular, INTR_FILTER}
2008-03-14 19:41:48 +00:00
Jeff Roberson
32c9d3a767 - Rather than repeating the same preemption code everywhere call the scheduler
specific sched_preempt() routine.
2008-03-10 01:32:48 +00:00
Jeff Roberson
81aa71755b - Remove the old smp cpu topology specification with a new, more flexible
tree structure that encodes the level of cache sharing and other
   properties.
 - Provide several convenience functions for creating one and two level
   cpu trees as well as a default flat topology.  The system now always
   has some topology.
 - On i386 and amd64 create a seperate level in the hierarchy for HTT
   and multi-core cpus.  This will allow the scheduler to intelligently
   load balance non-uniform cores.  Presently we don't detect what level
   of the cache hierarchy is shared at each level in the topology.
 - Add a mechanism for testing common topologies that have more information
   than the MD code is able to provide via the kern.smp.topology tunable.
   This should be considered a debugging tool only and not a stable api.

Sponsored by:	Nokia
2008-03-02 07:58:42 +00:00
Ruslan Ermilov
007b1b7bae Add a wrapper function that bound checks writes to the dump device. 2008-01-28 19:04:07 +00:00
Alan Cox
eb2a051720 Add an access type parameter to pmap_enter(). It will be used to implement
superpage promotion.

Correct a style error in kmem_malloc(): pmap_enter()'s last parameter is
a Boolean.
2008-01-03 07:34:34 +00:00
Alan Cox
b8e7fc24fe Add configuration knobs for the superpage reservation system. Initially,
the reservation will only be enabled on amd64.
2007-12-27 16:45:39 +00:00
Robert Watson
3de213cc00 Add a new 'why' argument to kdb_enter(), and a set of constants to use
for that argument.  This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.

Assign approximate why values to all current consumers of the
kdb_enter() interface.
2007-12-25 17:52:02 +00:00
Joseph Koshy
0da7aa7a7d Add stubs to unbreak LINT. 2007-12-07 13:45:47 +00:00
Robert Watson
3c90d1ea74 Break out stack(9) from ddb(4):
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
  definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
  defined, or also if "options DDB" is defined to provide compatibility
  with existing users of stack(9).

Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to.  It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.

Update stack(9) man page.

Build tested:	amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested:	amd64 (rwatson), arm (cognet), i386 (rwatson)
2007-12-02 20:40:35 +00:00
John Birrell
a9445e17cc Adjust the padding to account for the change of size of the MI part
of struct pcpu.
2007-11-29 20:50:40 +00:00
Attilio Rao
573c6b82df Make ADAPTIVE_GIANT as the default in the kernel and remove the option.
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.

Please don't forget to update your own custom config kernel files.

Approved by:	cognet, marcel (maintainers of arches where option is
		not enabled at the moment)
2007-11-28 05:50:45 +00:00
John Birrell
3aabc4d901 __builtin_stdarg_start was renamed to __builtin_va_start a long
time ago (2002 according to the gcc log). Using the proper name
fixes a warning in src/lib/libc/gen/ulimit.c about the second
argument of va_start() not being the last named (when it really
was).
2007-11-19 07:34:57 +00:00
Alan Cox
59677d3c0e Prevent the leakage of wired pages in the following circumstances:
First, a file is mmap(2)ed and then mlock(2)ed.  Later, it is truncated.
Under "normal" circumstances, i.e., when the file is not mlock(2)ed, the
pages beyond the EOF are unmapped and freed.  However, when the file is
mlock(2)ed, the pages beyond the EOF are unmapped but not freed because
they have a non-zero wire count.  This can be a mistake.  Specifically,
it is a mistake if the sole reason why the pages are wired is because of
wired, managed mappings.  Previously, unmapping the pages destroys these
wired, managed mappings, but does not reduce the pages' wire count.
Consequently, when the file is unmapped, the pages are not unwired
because the wired mapping has been destroyed.  Moreover, when the vm
object is finally destroyed, the pages are leaked because they are still
wired.  The fix is to reduce the pages' wired count by the number of
wired, managed mappings destroyed.  To do this, I introduce a new pmap
function pmap_page_wired_mappings() that returns the number of managed
mappings to the given physical page that are wired, and I use this
function in vm_object_page_remove().

Reviewed by: tegge
MFC after: 6 weeks
2007-11-17 22:52:29 +00:00
Marcel Moolenaar
0c3967e7fe o Rename cpu_thread_setup() to cpu_thread_alloc() to better
communicate that it relates to (is called by) thread_alloc()
o  Add cpu_thread_free() which is called from thread_free()
   to counter-act cpu_thread_alloc().

i386:	Have cpu_thread_free() call cpu_thread_clean() to
	preserve behaviour.
ia64:	Have cpu_thread_free() call mtx_destroy() for the
	mutex initialized in cpu_thread_alloc().

PR: ia64/118024
2007-11-14 20:21:54 +00:00
Julian Elischer
431f890614 generally we are interested in what thread did something as
opposed to what process. Since threads by default have teh name of the
process unless over-written with more useful information, just print the
thread name instead.
2007-11-14 06:21:24 +00:00
Marius Strobl
5077aaca20 Adjust the padding of struct pcpu to src/sys/sys/pcpu.h rev 1.23. 2007-11-11 12:30:56 +00:00
Konstantin Belousov
89b57fcf01 Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with:	Peter Holm
Reviewed by:	jhb
2007-11-05 11:36:16 +00:00
Julian Elischer
3745c395ec Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0  so that we can eventually MFC the
new kthread_xxx() calls.
2007-10-20 23:23:23 +00:00
Marius Strobl
55aaf894e8 Make the PCI code aware of PCI domains (aka PCI segments) so we can
support machines having multiple independently numbered PCI domains
and don't support reenumeration without ambiguity amongst the
devices as seen by the OS and represented by PCI location strings.
This includes introducing a function pci_find_dbsf(9) which works
like pci_find_bsf(9) but additionally takes a domain number argument
and limiting pci_find_bsf(9) to only search devices in domain 0 (the
only domain in single-domain systems). Bge(4) and ofw_pcibus(4) are
changed to use pci_find_dbsf(9) instead of pci_find_bsf(9) in order
to no longer report false positives when searching for siblings and
dupe devices in the same domain respectively.
Along with this change the sole host-PCI bridge driver converted to
actually make use of PCI domain support is uninorth(4), the others
continue to use domain 0 only for now and need to be converted as
appropriate later on.
Note that this means that the format of the location strings as used
by pciconf(8) has been changed and that consumers of <sys/pciio.h>
potentially need to be recompiled.

Suggested by:	jhb
Reviewed by:	grehan, jhb, marcel
Approved by:	re (kensmith), jhb (PCI maintainer hat)
2007-09-30 11:05:18 +00:00
Christian Brueffer
4fabde5686 Use the correct expanded name for SCTP.
PR:		116496
Submitted by:	koitsu
Reviewed by:	rrs
Approved by:	re (kensmith)
2007-09-26 20:05:07 +00:00
Alan Cox
7bfda801a8 Change the management of cached pages (PQ_CACHE) in two fundamental
ways:

(1) Cached pages are no longer kept in the object's resident page
splay tree and memq.  Instead, they are kept in a separate per-object
splay tree of cached pages.  However, access to this new per-object
splay tree is synchronized by the _free_ page queues lock, not to be
confused with the heavily contended page queues lock.  Consequently, a
cached page can be reclaimed by vm_page_alloc(9) without acquiring the
object's lock or the page queues lock.

This solves a problem independently reported by tegge@ and Isilon.
Specifically, they observed the page daemon consuming a great deal of
CPU time because of pages bouncing back and forth between the cache
queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE).  The source of
this problem turned out to be a deadlock avoidance strategy employed
when selecting a cached page to reclaim in vm_page_select_cache().
However, the root cause was really that reclaiming a cached page
required the acquisition of an object lock while the page queues lock
was already held.  Thus, this change addresses the problem at its
root, by eliminating the need to acquire the object's lock.

Moreover, keeping cached pages in the object's primary splay tree and
memq was, in effect, optimizing for the uncommon case.  Cached pages
are reclaimed far, far more often than they are reactivated.  Instead,
this change makes reclamation cheaper, especially in terms of
synchronization overhead, and reactivation more expensive, because
reactivated pages will have to be reentered into the object's primary
splay tree and memq.

(2) Cached pages are now stored alongside free pages in the physical
memory allocator's buddy queues, increasing the likelihood that large
allocations of contiguous physical memory (i.e., superpages) will
succeed.

Finally, as a result of this change long-standing restrictions on when
and where a cached page can be reclaimed and returned by
vm_page_alloc(9) are eliminated.  Specifically, calls to
vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and
return a formerly cached page.  Consequently, a call to malloc(9)
specifying M_NOWAIT is less likely to fail.

Discussed with: many over the course of the summer, including jeff@,
   Justin Husted @ Isilon, peter@, tegge@
Tested by: an earlier version by kris@
Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
Alan Cox
6bce07ae73 It has been observed on the mailing lists that the different categories
of pages don't sum to anywhere near the total number of pages on amd64.
This is for the most part because uma_small_alloc() pages have never been
counted as wired pages, like their kmem_malloc() brethren.  They should
be.  This changes fixes that.

It is no longer necessary for the page queues lock to be held to free
pages allocated by uma_small_alloc().  I removed the acquisition and
release of the page queues lock from uma_small_free() on amd64 and ia64
weeks ago.  This patch updates the other architectures that have
uma_small_alloc() and uma_small_free().

Approved by: re (kensmith)
2007-09-15 18:47:02 +00:00
Attilio Rao
0b2e598c14 This is a follow-up, cleaning-up commit about recent changes involving
topology foo functions.
Working at the patch for topology problems in ia32/amd64 evicted some
problems regarding functions ordering in the SI_SUB_CPU family of
SYSINIT'ed subsystems.
In order to avoid problems with new modified to involved functions, a
correct ordering is not semantically specified for SI_SUB_CPU functions
(for a larger view of the issue please visit:
http://lists.freebsd.org/pipermail/freebsd-current/2007-July/075409.html )

Discussed with: peter
Tested by: kris, Rui Paulo <rpaulo@FreeBSD.org>
Approved by: jeff
Approved by: re
2007-09-11 22:54:09 +00:00
Peter Wemm
c5b102f584 Fix warning - add missing #include
Submitted by:	mjacob
Approved by:	re (rwatson)
2007-07-06 00:41:53 +00:00
Marius Strobl
838f76c0a9 - Restore the machine independency of sys/dev/ofw/openfirm.{c,h} by
moving OF_set_mmfsa_traptable() (SUNW,set-trap-table with the two
  arguments used here is specific to sun4v) to MD code.
- In sys/dev/ofw/openfirm.h remove prototypes for unimplemented
  functions and unused Solaris compatibility macros.
2007-06-16 22:30:38 +00:00
Alan Cox
2446e4f02c Enable the new physical memory allocator.
This allocator uses a binary buddy system with a twist.  First and
foremost, this allocator is required to support the implementation of
superpages.  As a side effect, it enables a more robust implementation
of contigmalloc(9).  Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).

The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages.  Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space.  The performance benefits vary.  In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.

This allocator does not implement page coloring.  The reason is that
superpages have much the same effect.  The contiguous physical memory
allocation necessary for a superpage is inherently colored.

Finally, the one caveat is that this allocator does not effectively
support prezeroed pages.  I hope this is temporary.  On i386, this is
a slight pessimization.  However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects.  I speculate
that this is true in general of machines with a direct map.

Approved by:	re
2007-06-16 04:57:06 +00:00
Xin LI
a2346f7c3c Enable SCTP by default for GENERIC kernels in order to give it
more exposure.  The current state of SCTP implementation is
considered to be ready for 32-bit platforms, but still need some
work/testing on 64-bit platforms.

Approved by:	re (kensmith)
Discussed with:	rrs
2007-06-14 17:14:27 +00:00
Kip Macy
d84d0dfee6 fix cassert failure by adjusting padding 2007-06-12 21:19:12 +00:00
Marcel Moolenaar
2b39bb4f4f Use default options for default partitioning schemes, rather than
making the relevant files standard. This avoids duplication and
makes it easier to override/disable unwanted schemes. Since ARM
doesn't have a DEFAULTS configuration file, leave the source
files for the BSD and MBR partitioning schemes in files.arm for
now.
2007-06-11 00:38:06 +00:00
Marcel Moolenaar
01bd17cc99 Add kdb_cpu_sync_icache(), intended to synchronize instruction
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.
2007-06-09 21:55:17 +00:00
Robert Watson
68d4cc614a Enable AUDIT by default in the GENERIC kernel, allowing security event
auditing to be turned on without a kernel recompile, just an rc.conf
option.

Approved by:	re (kensmith)
Obtained from:	TrustedBSD Project
2007-06-08 20:29:07 +00:00
Jeff Roberson
1b1618fb12 - Change comments and asserts to reflect the removal of the global
scheduler lock.

Tested by:      kris, current@
Tested on:      i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:57:32 +00:00
Jeff Roberson
e4b5aee3a8 Commit 10/14 of sched_lock decomposition.
- Use sched_throw() rather than replicating the same cpu_throw() code for
   each architecture.  This also allows the scheduler to use any locking it
   may want to.
 - Use the thread_lock() rather than sched_lock when preempting.
 - The scheduler lock is not required to synchronize release_aps.

Tested by:      kris, current@
Tested on:      i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:56:08 +00:00
Attilio Rao
6759608248 Rework the PCPU_* (MD) interface:
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
  given a specific value.

Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.

Reviewed by: alc, bde
Approved by: jeff (mentor)
2007-06-04 21:38:48 +00:00
Alan Cox
c63f556284 Add the machine-specific definitions for configuring the new physical
memory allocator.

Approved by:	re
2007-06-03 23:33:11 +00:00
Attilio Rao
2feb50bf7d Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)
2007-05-31 22:52:15 +00:00
Paolo Pisati
3401f2c1df In some particular cases (like in pccard and pccbb), the real device
handler is wrapped in a couple of functions - a filter wrapper and an
ithread wrapper. In this case (and just in this case), the filter
wrapper could ask the system to schedule the ithread and mask the
interrupt source if the wrapped handler is composed of just an ithread
handler: modify the "old" interrupt code to make it support
this situation, while the "new" interrupt code is already ok.

Discussed with: jhb
2007-05-31 19:25:35 +00:00
Pyun YongHyeon
590f73f72e Honor maxsegsz of less than a page size in a DMA tag. Previously it
used to return PAGE_SIZE without respect to restrictions of a DMA tag.
This affected all of the busdma load functions that use
_bus_dmamap_loader_buffer() as their back-end.

Reviewed by:	scottl
2007-05-29 06:30:26 +00:00