busdma: kill filter functionality internally

Address filter functions are unused, unsupported, and now rejected.
Simplify some busdma code by removing filter functionality completely.

Note that the chains of parent tags become useless, and will be cleaned
up in the next commit.

No functional change intended.

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D42894

sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

spdx: The BSD-2-Clause-NetBSD identifier is obsolete, drop -NetBSD

The SPDX folks have obsoleted the BSD-2-Clause-NetBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

bus_dma: Deduplicate locking helper functions.

- Move busdma_lock_mutex to subr_bus_dma.c.

- Move _busdma_lock_dflt to subr_bus_dma.c. This function was named a
couple of different things previously. It is not a public API but
an internal helper used in place of a NULL pointer. The prototype
is in <sys/bus_dma.h> as not all backends include
<sys/bus_dma_internal.h>.

Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D33694

Refine the busdma template interface. Provide tools for filling in fields
that can be extended, but also ensure compile-time type checking. Refactor
common code out of arch-specific implementations. Move the mpr and mps
drivers to this new API. The template type remains visible to the consumer
so that it can be allocated on the stack, but should be considered opaque.

Add support for optional separate output buffers to in-kernel crypto.

Some crypto consumers such as GELI and KTLS for file-backed sendfile
need to store their output in a separate buffer from the input.
Currently these consumers copy the contents of the input buffer into
the output buffer and queue an in-place crypto operation on the output
buffer. Using a separate output buffer avoids this copy.

- Create a new 'struct crypto_buffer' describing a crypto buffer
containing a type and type-specific fields. crp_ilen is gone,
instead buffers that use a flat kernel buffer have a cb_buf_len
field for their length. The length of other buffer types is
inferred from the backing store (e.g. uio_resid for a uio).
Requests now have two such structures: crp_buf for the input buffer,
and crp_obuf for the output buffer.

- Consumers now use helper functions (crypto_use_*,
e.g. crypto_use_mbuf()) to configure the input buffer. If an output
buffer is not configured, the request still modifies the input
buffer in-place. A consumer uses a second set of helper functions
(crypto_use_output_*) to configure an output buffer.

- Consumers must request support for separate output buffers when
creating a crypto session via the CSP_F_SEPARATE_OUTPUT flag and are
only permitted to queue a request with a separate output buffer on
sessions with this flag set. Existing drivers already reject
sessions with unknown flags, so this permits drivers to be modified
to support this extension without requiring all drivers to change.

- Several data-related functions now have matching versions that
operate on an explicit buffer (e.g. crypto_apply_buf,
crypto_contiguous_subsegment_buf, bus_dma_load_crp_buf).

- Most of the existing data-related functions operate on the input
buffer. However crypto_copyback always writes to the output buffer
if a request uses a separate output buffer.

- For the regions in input/output buffers, the following conventions
are followed:
- AAD and IV are always present in input only and their
fields are offsets into the input buffer.
- payload is always present in both buffers. If a request uses a
separate output buffer, it must set a new crp_payload_start_output
field to the offset of the payload in the output buffer.
- digest is in the input buffer for verify operations, and in the
output buffer for compute operations. crp_digest_start is relative
to the appropriate buffer.

- Add a crypto buffer cursor abstraction. This is a more general form
of some bits in the cryptosoft driver that tried to always use uio's.
However, compared to the original code, this avoids rewalking the uio
iovec array for requests with multiple vectors. It also avoids
allocate an iovec array for mbufs and populating it by instead walking
the mbuf chain directly.

- Update the cryptosoft(4) driver to support separate output buffers
making use of the cursor abstraction.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D24545

Refactor driver and consumer interfaces for OCF (in-kernel crypto).

- The linked list of cryptoini structures used in session
initialization is replaced with a new flat structure: struct
crypto_session_params. This session includes a new mode to define
how the other fields should be interpreted. Available modes
include:

- COMPRESS (for compression/decompression)
- CIPHER (for simply encryption/decryption)
- DIGEST (computing and verifying digests)
- AEAD (combined auth and encryption such as AES-GCM and AES-CCM)
- ETA (combined auth and encryption using encrypt-then-authenticate)

Additional modes could be added in the future (e.g. if we wanted to
support TLS MtE for AES-CBC in the kernel we could add a new mode
for that. TLS modes might also affect how AAD is interpreted, etc.)

The flat structure also includes the key lengths and algorithms as
before. However, code doesn't have to walk the linked list and
switch on the algorithm to determine which key is the auth key vs
encryption key. The 'csp_auth_*' fields are always used for auth
keys and settings and 'csp_cipher_*' for cipher. (Compression
algorithms are stored in csp_cipher_alg.)

- Drivers no longer register a list of supported algorithms. This
doesn't quite work when you factor in modes (e.g. a driver might
support both AES-CBC and SHA2-256-HMAC separately but not combined
for ETA). Instead, a new 'crypto_probesession' method has been
added to the kobj interface for symmteric crypto drivers. This
method returns a negative value on success (similar to how
device_probe works) and the crypto framework uses this value to pick
the "best" driver. There are three constants for hardware
(e.g. ccr), accelerated software (e.g. aesni), and plain software
(cryptosoft) that give preference in that order. One effect of this
is that if you request only hardware when creating a new session,
you will no longer get a session using accelerated software.
Another effect is that the default setting to disallow software
crypto via /dev/crypto now disables accelerated software.

Once a driver is chosen, 'crypto_newsession' is invoked as before.

- Crypto operations are now solely described by the flat 'cryptop'
structure. The linked list of descriptors has been removed.

A separate enum has been added to describe the type of data buffer
in use instead of using CRYPTO_F_* flags to make it easier to add
more types in the future if needed (e.g. wired userspace buffers for
zero-copy). It will also make it easier to re-introduce separate
input and output buffers (in-kernel TLS would benefit from this).

Try to make the flags related to IV handling less insane:

- CRYPTO_F_IV_SEPARATE means that the IV is stored in the 'crp_iv'
member of the operation structure. If this flag is not set, the
IV is stored in the data buffer at the 'crp_iv_start' offset.

- CRYPTO_F_IV_GENERATE means that a random IV should be generated
and stored into the data buffer. This cannot be used with
CRYPTO_F_IV_SEPARATE.

If a consumer wants to deal with explicit vs implicit IVs, etc. it
can always generate the IV however it needs and store partial IVs in
the buffer and the full IV/nonce in crp_iv and set
CRYPTO_F_IV_SEPARATE.

The layout of the buffer is now described via fields in cryptop.
crp_aad_start and crp_aad_length define the boundaries of any AAD.
Previously with GCM and CCM you defined an auth crd with this range,
but for ETA your auth crd had to span both the AAD and plaintext
(and they had to be adjacent).

crp_payload_start and crp_payload_length define the boundaries of
the plaintext/ciphertext. Modes that only do a single operation
(COMPRESS, CIPHER, DIGEST) should only use this region and leave the
AAD region empty.

If a digest is present (or should be generated), it's starting
location is marked by crp_digest_start.

Instead of using the CRD_F_ENCRYPT flag to determine the direction
of the operation, cryptop now includes an 'op' field defining the
operation to perform. For digests I've added a new VERIFY digest
mode which assumes a digest is present in the input and fails the
request with EBADMSG if it doesn't match the internally-computed
digest. GCM and CCM already assumed this, and the new AEAD mode
requires this for decryption. The new ETA mode now also requires
this for decryption, so IPsec and GELI no longer do their own
authentication verification. Simple DIGEST operations can also do
this, though there are no in-tree consumers.

To eventually support some refcounting to close races, the session
cookie is now passed to crypto_getop() and clients should no longer
set crp_sesssion directly.

- Assymteric crypto operation structures should be allocated via
crypto_getkreq() and freed via crypto_freekreq(). This permits the
crypto layer to track open asym requests and close races with a
driver trying to unregister while asym requests are in flight.

- crypto_copyback, crypto_copydata, crypto_apply, and
crypto_contiguous_subsegment now accept the 'crp' object as the
first parameter instead of individual members. This makes it easier
to deal with different buffer types in the future as well as
separate input and output buffers. It's also simpler for driver
writers to use.

- bus_dmamap_load_crp() loads a DMA mapping for a crypto buffer.
This understands the various types of buffers so that drivers that
use DMA do not have to be aware of different buffer types.

- Helper routines now exist to build an auth context for HMAC IPAD
and OPAD. This reduces some duplicated work among drivers.

- Key buffers are now treated as const throughout the framework and in
device drivers. However, session key buffers provided when a session
is created are expected to remain alive for the duration of the
session.

- GCM and CCM sessions now only specify a cipher algorithm and a cipher
key. The redundant auth information is not needed or used.

- For cryptosoft, split up the code a bit such that the 'process'
callback now invokes a function pointer in the session. This
function pointer is set based on the mode (in effect) though it
simplifies a few edge cases that would otherwise be in the switch in
'process'.

It does split up GCM vs CCM which I think is more readable even if there
is some duplication.

- I changed /dev/crypto to support GMAC requests using CRYPTO_AES_NIST_GMAC
as an auth algorithm and updated cryptocheck to work with it.

- Combined cipher and auth sessions via /dev/crypto now always use ETA
mode. The COP_F_CIPHER_FIRST flag is now a no-op that is ignored.
This was actually documented as being true in crypto(4) before, but
the code had not implemented this before I added the CIPHER_FIRST
flag.

- I have not yet updated /dev/crypto to be aware of explicit modes for
sessions. I will probably do that at some point in the future as well
as teach it about IV/nonce and tag lengths for AEAD so we can support
all of the NIST KAT tests for GCM and CCM.

- I've split up the exising crypto.9 manpage into several pages
of which many are written from scratch.

- I have converted all drivers and consumers in the tree and verified
that they compile, but I have not tested all of them. I have tested
the following drivers:

- cryptosoft
- aesni (AES only)
- blake2
- ccr

and the following consumers:

- cryptodev
- IPsec
- ktls_ocf
- GELI (lightly)

I have not tested the following:

- ccp
- aesni with sha
- hifn
- kgssapi_krb5
- ubsec
- padlock
- safe
- armv8_crypto (aarch64)
- glxsb (i386)
- sec (ppc)
- cesa (armv7)
- cryptocteon (mips64)
- nlmsec (mips64)

Discussed with: cem
Relnotes: yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D23677

Introduce the concept of busdma tag templates. A template can be allocated
off the stack, initialized to default values, and then filled in with
driver-specific values, all without having to worry about the numerous
other fields in the tag. The resulting template is then passed into
busdma and the normal opaque tag object created. See the man page for
details on how to initialize a template.

Templates do not support tag filters. Filters have been broken for many
years, and only existed for an ancient make/model of hardware that had a
quirky DMA engine. Instead of breaking the ABI/API and changing the
arugment signature of bus_dma_tag_create() to remove the filter arguments,
templates allow us to ignore them, and also significantly reduce the
complexity of creating and managing tags.

Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D22906

Allow loading the same DMA address multiple times without any prior
unload for the LinuxKPI.

Reviewed by: kib, zeising
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20181

Remove a trailing whitspace.

Add support for NUMA domains to bus dma tags. This causes all memory
allocated with a tag to come from the specified domain if it meets the
other constraints provided by the tag. Automatically create a tag at
the root of each bus specifying the domain local to that bus if
available.

Reviewed by: jhb, kib
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13545

SPDX: mostly fixes to previous changes.

Introduce the recently approved BSD-1-Clause and replace 0BSD which
never did fit well our use cases.

sys/sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Clean up MD pollution of bus_dma.h:

--Remove special-case handling of sparc64 bus_dmamap* functions.
Replace with a more generic mechanism that allows MD busdma
implementations to generate inline mapping functions by
defining WANT_INLINE_DMAMAP in <machine/bus_dma.h>. This
is currently useful for sparc64, x86, and arm64, which all
implement non-load dmamap operations as simple wrappers
around map objects which may be bus- or device-specific.

--Remove NULL-checked bus_dmamap macros. Implement the
equivalent NULL checks in the inlined x86 implementation.
For non-x86 platforms, these checks are a minor pessimization
as those platforms do not currently allow NULL maps. NULL
maps were originally allowed on arm64, which appears to have
been the motivation behind adding arm[64]-specific barriers
to bus_dma.h, but that support was removed in r299463.

--Simplify the internal interface used by the bus_dmamap_load*
variants and move it to bus_dma_internal.h

--Fix some drivers that directly include sys/bus_dma.h
despite the recommendations of bus_dma(9)

Reviewed by: kib (previous revision), marius
Differential Revision: https://reviews.freebsd.org/D10729

Style cleanups after r285270

There should be no semicolons in added macro definitions.
Define empty macro as "do {} while (0)".

Pointed out by: jmg

Add memory barrier to bus_dmamap_sync()

On platforms which are fully IO-coherent, the map might be null.
We need to guarantee that all data is observable after the
sync operation is called. Add a memory barrier to ensure that on ARM.

Reviewed by: andrew, kib
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3012

Update NetBSD Foundation copyrights to 2-clause BSD

The NetBSD Foundation states "Third parties are encouraged to change the
license on any files which have a 4-clause license contributed to the
NetBSD Foundation to a 2-clause license."

This change removes clauses 3 and 4 from copyright / license blocks that
list The NetBSD Foundation as the only copyright holder.

Sponsored by: The FreeBSD Foundation

Add bus_dmamap_load_ma() function to load map with the array of
vm_pages. Provide trivial implementation which forwards the load to
_bus_dmamap_load_phys() page by page. Right now all architectures use
bus_dmamap_load_ma_triv().

Tested by: pho (as part of the functional patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 month

Add bus_dmamap_load_bio for non-CAM disk drivers that wish to enable
unmapped I/O.

Sponsored by: Intel
Reviewed by: kib

Reform the busdma API so that new types may be added without modifying
every architecture's busdma_machdep.c. It is done by unifying the
bus_dmamap_load_buffer() routines so that they may be called from MI
code. The MD busdma is then given a chance to do any final processing
in the complete() callback.

The cam changes unify the bus_dmamap_load* handling in cam drivers.

The arm and mips implementations are updated to track virtual
addresses for sync(). Previously this was done in a type specific
way. Now it is done in a generic way by recording the list of
virtuals in the map.

Submitted by: jeff (sponsored by EMC/Isilon)
Reviewed by: kan (previous version), scottl,
mjacob (isp(4), no objections for target mode changes)
Discussed with: ian (arm changes)
Tested by: marius (sparc64), mips (jmallet), isci(4) on x86 (jharris),
amd64 (Fabian Keil <freebsd-listen@fabiankeil.de>)

- Change contigmalloc() to use the vm_paddr_t type instead of an unsigned
long for specifying a boundary constraint.
- Change bus_dma tags to use bus_addr_t instead of bus_size_t for boundary
constraints.

These allow boundary constraints to be fully expressed for cases where
sizeof(bus_addr_t) != sizeof(bus_size_t). Specifically, it allows a
driver to properly specify a 4GB boundary in a PAE kernel.

Note that this cannot be safely MFC'd without a lot of compat shims due
to KBI changes, so I do not intend to merge it.

Reviewed by: scottl

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Trivially switch amd64 to the common busdma implementation.
Eliminate ARM specific kluges in the API definitions and
remove #ifndef __sparc64__ surrounding the prototypes.

When bouncing pages, allow a new option to preserve the intra-page
offset. This is needed for the ehci hardware buffer rings that assume
this behavior.

This is an interim solution, and a more general one is being worked
on. This solution doesn't break anything that doesn't ask for it
directly. The mbuf and uio variants with this flag likely don't work
and haven't been tested.

Universe builds with these changes. I don't have a huge-memory
machine to test these changes with, but will be happy to work with
folks that do and hps if this changes turns out not to be sufficient.

Submitted by: alfred@ from Hans Peter Selasky's original

- Import the HEAD csup code which is the basis for the cvsmode work.

BUS_DMA_ISA is left over from Alpha, and is not used in the tree at
all. The reference in ia64 code is due to cutNpaste in its history
and can safely be removed.

Revired by: cognet, raj, marcel, jhb and maybe one other whom I'm forgetting

Break out typedefs from bus_dma.h to _bus_dma.h so that we can get the
typedef for bus_dma_tag_t in sys/bus.h w/o poluting the namespace...
This is in preperation for adding bus_get_dma_tag to sys/bus.h...

fix arm wrt to busdma...

also wrap the two macros that have bare if's w/ do {} while(0) so that
my epe driver doesn't get a warning about braces around confused else...

Refactor the bus_dma header files so that the interface is described in
sys/bus_dma.h instead of being copied in every single arch. This slightly
reorders a flag that was specific to AXP and thus changes the ABI there.
The interface still relies on bus_space definitions found in <machine/bus.h>
so it cannot be included on its own yet, but that will be fixed at a later
date. Add an MD <machine/bus_dma.h> for ever arch for consistency and to
allow for future MD augmentation of the API. sparc64 makes heavy use of
this right now due to its different bus_dma implemenation.

Introduce bus_dmamap_load_mbuf_sg(). Instead of taking a callback arg, this
cuts to the chase and fills in a provided s/g list. This is meant to optimize
out the cost of the callback since the callback doesn't serve much purpose for
mbufs since mbuf loads will never be deferred. This is just for amd64 and
i386 at the moment, other arches will be coming shortly.

/* -> /*- for copyright notices, minor format tweaks as necessary

Document the lockfunc and lockfuncarg arguments to bus_dma_tag_create() in
the busdma headers.

Spelling and grammar fixes.

PR: kern/54658
Submitted by: Roderick van Domburg <r.s.a.vandomburg@student.utwente.nl>

- Introduce a new busdma flag BUS_DMA_ZERO to request for zero'ed
memory in bus_dmamem_alloc(). This is possible now that
contigmalloc() supports the M_ZERO flag.
- Remove the locking of Giant around calls to contigmalloc() since
contigmalloc() now grabs Giant itself.

Mega busdma API commit.

Add two new arguments to bus_dma_tag_create(): lockfunc and lockfuncarg.
Lockfunc allows a driver to provide a function for managing its locking
semantics while using busdma. At the moment, this is used for the
asynchronous busdma_swi and callback mechanism. Two lockfunc implementations
are provided: busdma_lock_mutex() performs standard mutex operations on the
mutex that is specified from lockfuncarg. dftl_lock() is a panic
implementation and is defaulted to when NULL, NULL are passed to
bus_dma_tag_create(). The only time that NULL, NULL should ever be used is
when the driver ensures that bus_dmamap_load() will not be deferred.
Drivers that do not provide their own locking can pass
busdma_lock_mutex,&Giant args in order to preserve the former behaviour.

sparc64 and powerpc do not provide real busdma_swi functions, so this is
largely a noop on those platforms. The busdma_swi on is64 is not properly
locked yet, so warnings will be emitted on this platform when busdma
callback deferrals happen.

If anyone gets panics or warnings from dflt_lock() being called, please
let me know right away.

Reviewed by: tmm, gibbs

Rename BUS_DMAMEM_NOSYNC to BUS_DMA_COHERENT.

The current name is confusing, because it indicates to
the client that a bus_dmamap_sync() operation is not
necessary when the flag is specified, which is wrong.

The main purpose of this flag is to hint the underlying
architecture that DMA memory should be mapped in a coherent
way, but the architecture can ignore it. But if the
architecture does supports coherent mapping of memory, then
it makes bus_dmamap_sync() calls cheap.

This flag is the same as the one in NetBSD's Bus DMA.

Reviewed by: gibbs, scottl, des (implicitly)
Approved by: re@ (jhb)

Bring back bus_dmasync_op_t. It is now a typedef to an int, though the
BUS_DMASYNC_ definitions remain as before. The does not change the ABI,
and reverts the API to be a bit more compatible and flexible. This has
survived a full 'make universe'.

Approved by: re (bmah)

De-orbit bus_dmamem_alloc_size(). It's a hack and was never used anyways.
No need for it to pollute the 5.x API any further.

Approved by: re (bmah)

Change the operation parameter of bus_dmamap_sync() from an
enum to an int and redefine the BUS_DMASYNC_* constants as
flags. This allows us to specify several operations in one
call to bus_dmamap_sync() as in NetBSD.

Implement bus_dmamem_alloc_size() and bus_dmamem_free_size() as
counterparts to bus_dmamem_alloc() and bus_dmamem_free(). This allows
the caller to specify the size of the allocation instead of it defaulting
to the max_size field of the busdma tag.

This is intended to aid in converting drivers to busdma. Lots of
hardware cannot understand scatter/gather lists, which forces the
driver to copy the i/o buffers to a single contiguous region
before sending it to the hardware. Without these new methods, this
would require a new busdma tag for each operation, or a complex
internal allocator/cache for each driver.

Allocations greater than PAGE_SIZE are rounded up to the next
PAGE_SIZE by contigmalloc(), so this is not suitable for multiple
static allocations that would be better served by a single
fixed-length subdivided allocation.

Reviewed by: jake (sparc64)

New bus_dma interfaces for use by crypto device drivers:

o bus_dmamap_load_mbuf
o bus_dmamap_load_uio

Test on i386. Known to compile on alpha and sparc64, but not tested.
Otherwise untried.

- Moved the bus_dma declarations from bus_{at386,pc98}.h into bus_dma.h.
(bus_dma.h is repo-copied from bus_at386.h)
- Added '#include <machine/bus_dma.h>' into bus.h for backward compatibility.

Fix "alignemnt" typo.

version 1.7 made some changes to correct problems identifed by compiling
with egcs-1.1.1. bus_space_write_multi_2() had an extra operation that
should have been removed.

Remove it.

This fixes the panic when bus_space_write_multi_2() is used.

Obtained from: jake

Axe the barrier_{read,write,rw}() helper functions as this method of
doing memory barriers doesn't really scale well for the ia64. Also,
memory barriers are more a property of the CPU than bus space.

Requested by: dfr

Add in a simple API for memory barriers to machine/bus.h:
- barrier_read() enforces a memory read barrier
- barrier_write() enforces a memory write barrier
- barrier_rw() enforces a memory read/write barrier

Fixed syntax errors and style bugs in previous commit. The syntax
errors were normally harmless because they were in unreachable code
and gcc apparently doesn't check the syntax inside asm statements
that it optimizes away.

Implement real read/write barriers for the i386. Despite the comment in
previous versions of this file, some barrier functionality is required.

Added indirect pio into the bus space stuff for the NEC PC-98. bus.h
includes one of bus_at386.h and bus_pc98.h. Becuase only bus_pc98.h
supports indirect pio and bus_at386.h is identical to old bus.h, there
is no functional change in PC-AT's kernels. That is, it cannot cause
performance loss.

Submitted by: nyan
Reviewed by: imp
bde and luoqi provided useful comments for earlier version.

Fix clobbers so that GENERIC may compile with GCC 2.95.2.

Historically, the documentation of extended asm was lacking, namely you
should NOT specify the same register as an input, and a clobber.
If the register is clobbered, it should be specified as an output as well,
e.g., by linking input and output through the "number" notation.
(Beware of lvalues, some local variables needed...)

URL:http://egcs.cygnus.com/faq.html

In versions up to egcs-1.1.1, the compiler did not even warn about it,
but it was liable to output bad code. Newer egcs are pickier and simply
refuse to swallow such code.

Note, since *addr changes, it needs to be an output operand.
We might be excessive in saying that all memory has changed.

Obtained from: OpenBSD
w/extra thanks to Marc Espie <Marc.Espie@liafa.jussieu.fr>

$Id$ -> $FreeBSD$

Improve compatibility with other systems by changing the default
behavior slightly.

If machine/bus.h is included, but neither bus_memio.h nor bus_pio.h
are included, then behave as if both were included.

This won't change existing drivers, all of which include one or more
of bus_{p,mem}io.h, but will allow drivers from other systems to come
over with fewer changes. I freely admit that this might not be
optimal for some drivers, but those drivers can be optimized for
FreeBSD after the initial bringup happens.

Without the change, there is a bug that preclude drivers from
compiling with strange warning/errors.

I've been running this here for a while now w/o ill effects.

Reviewed by: gibbs
Not objected to by: bde, arch@ list.

Don't pretend to support ix86's with 16-bit ints by using longs just
to ensure 32-bit variables. Doing so broke ix86's with 64-bit longs.

Implement bus_dmamem_* functions and correct a few nits reported by Peter Wemm.

Support compiling with `gcc-pedantic' (don't use hard newlines in
(asm) string constants or trailing commas in enum declarations).

Implementation of Bus Space for FreeBSD-x86.

Obtained From: NetBSD