kernel/dma_resource: Add an assertion to prevent Init() from being called twice.

kernel/dma_resource: Fix tracing.

DMAResource: Validate that alignment <= block_size.

The code here cannot handle the case where alignment > block_size,
so anything calling Init() with these parameters is invalid.

Fixes #15902 (nvme_disk was long since adjusted, so this is a defense
against code being written in the future.)

DMAResource: Remove incorrect early unlock.

When bounce buffers were changed from fixed to dynamic in hrev27185, the
early unlock in case of physical vectors was not removed. This would
lead to an unprotected fBounceBuffers list and the possibility for
multiple operations to share the same bounce buffer vecs, leading to
disk corruption. This would not happen when used purely under the
IOScheduler as all translations are done from a single thread there.
With the nvme_disk driver that runs requests in parallel, this was
however easy to trigger.

Change-Id: I46bd55cd5d86174523d3f745b6c8800dae02babc
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2524
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

white space cleanup

DMAResource: mutex_lock() before calling mutex_destroy().

device_manager: init DMAResource::fScratchVecs.

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.

More 64-bit compilation/safety fixes.

Merged the signals branch into trunk, with these changes:
* The team and thread kernel structures have been renamed to Team and Thread
respectively and moved into the new BKernel namespace.
* Several (kernel add-on) sources have been converted from C to C++ since
private kernel headers are included that are no longer C compatible.

Changes after merging:
* Fixed gcc 2 build (warnings mainly in the scary firewire bus manager).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40196 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::Init(): Also evaluate the device node's B_DMA_LOW_ADDRESS and
B_DMA_HIGH_ADDRESS attributes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37143 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixed more address types related issues. Mostly printf() or comparison
warnings, but also some oversights from earlier changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37000 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced type generic_io_vec, which is similar to iovec, but uses types
that are wide enough for both virtual and physical addresses.
* DMABuffer, IORequest, IOScheduler,... and code using them: Use
generic_io_vec and generic_{addr,size}_t where necessary.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36997 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Changed physical_entry::{address,size} to phys_{addr,size}_t and changed
map_physical_memory()'s physicalAddress parameter type from void* to
phys_addr_t. This breaks source compatibility, but -- as long as
phys_{addr,size}_t remain 32 bit wide -- keeps binary compatibility with
BeOS.
* Adjusted all code using the affected interfaces (Oh what fun!). Added a few
TODOs in places where the wrong types (e.g. void* for physical addresses
are used). Looks like quite a few drivers aren't 64 bit safe and others
will break with PAE.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36960 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed src/system/kernel/device_manager/io_requests.{h,cpp} to
IORequest.{h,cpp}.
* Introduced public <io_requests.h> header. Currently it only declares the
single function BFS uses.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29446 a95241bf-73f2-0310-859d-f6bbb57e9c96

* DMAResource::TranslateNext(): Added parameter to limit the maximum
operation length.
* IORequest: Added owner (IORequestOwner). Also added a SetUnfinished()
method, which is invoked by the I/O scheduler after all operations of
the request have been finished, but the request isn't done yet.
* Added debugger commands "io_request_owner" and "io_scheduler" printing
information for a IORequestOwner and IOScheduler object respectively.
* Implemented an actual I/O scheduling algorithm. It's a simple round
robin strategy (a queue per thread) with a unidirectional elevator
serializing the operations. ATM priorities are ignored, the bandwidth
isn't adjusted to the device, and there are TODOs all over the place.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27216 a95241bf-73f2-0310-859d-f6bbb57e9c96

A DMABuffer doesn't have a fixed bounce buffer assigned anymore. We do
dynamically assign one when needed. Under the assumption that in most
cases a bounce buffer isn't needed, we can thus prepare a lot more
operations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27185 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::TranslateNext(): Fixed several bugs that could cause too
many bytes to be read/written, which, among other things, could trigger
an assert in the IORequest code:
* In case of a partial (i.e. non-block-aligned) begin, transferLeft was
not adjusted correctly.
* The main loop was lacking a transferLeft check.
* Main loop: When finally using a bounce buffer, the unrestricted vec
length was used as base length for the bounce buffer.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27042 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Replaced the B_BLOCK_DEVICE_* defines with B_DMA_* defines that better match
our dma_restrictions structure (but we're using blocks instead of bytes,
since unlike the block size, the restrictions attributes are constant).
* We might want to use blocks for the dma_restrictions structure as well in
the future...
* Fixed another bug in the device_node variant of DMAResource::Init(): the max
segment size was specified in blocks as well.
* Removed the "hardcode" block_io module and header.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26973 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the mix of bufferCount vs. max_segment_count with regards to
B_BLOCK_DEVICE_MAX_SG_BLOCKS as pointed out by Ingo.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26972 a95241bf-73f2-0310-859d-f6bbb57e9c96

Another hard code (DMAResource::TranslateNext()) fix: In the write case
if after the main loop the transfer is already block aligned, we still
have to check whether the last vec is a bounce buffer that is shorter
than a complete block, but exceeds the original end of the request. If
so, we have to cut back to the previous block and add a block-sized
bounce buffer instead. Actually that's almost the same case as when the
transfer length is not yet block aligned, and thus we let the same code
handle it. Fixes bug #2584.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26910 a95241bf-73f2-0310-859d-f6bbb57e9c96

* When creating the physical vector array, we did not advance "base" in the
loop.
* This is probably the cause for file corruptions as well as bug #2595; will
have another look tomorrow.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26905 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::TranslateNext(), in case of given physical vecs:
* segmentCount was potentially set incorrectly. It could be too big,
since we considered all vecs, not only those remaining.
* The main loop condition was incorrect. This would lead to too few
DMABuffer vecs (or none at all) for any but the first IOOperation of a
request. Should fix #2586.
* Correctly offset by vecIndex in debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26881 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added Dump() method to IORequest, IOOperation, IOBuffer, and DMABuffer.
* Added KDL commands "io_request", "io_operation", "io_buffer", and
"dma_buffer".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26838 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a DMAResource::Init() method that gets a device node - for now, it will
reuse the block_io attributes in the node to build the dma_restrictions.
* DMAResource::Init() now dumps the dma_resources (should be done with the
TRACE() macro later).
* Turned off IOScheduler debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26825 a95241bf-73f2-0310-859d-f6bbb57e9c96

* It is now supported that I/O operations and requests are only handled
partially (e.g. due to hitting the end of file). The respective
classes have grown new methods and attributes to deal with that. The
"finished" callbacks have got additional parameters to indicate
whether the transfer was only partial and how much has been
transferred. Other callbacks and functions have a size_t* in/out
parameter instead of a simple size_t, now.
* vfs_{read,write}_pages() do now use the I/O request framework instead
of the underlying FS's {read,write}_pages() hooks (those should be
unused now). Furthermore they've got an additional "flags" parameter,
which is passed to IORequest::Init(), i.e. it allows to specify that
the given vecs refer to physical addresses.
* The file cache's read_into_cache() reads directly into physical
pages, now.
* Fixed bug in DoIO::IO(): The offset was not adjusted, so that all
pages were incorrectly transferred from/to the same location.
* Fixed broken subrequest scheduling loop head in
do_iterative_fd_io_iterate().
* Adjusted the test driver and implemented its io() hook. Using this
driver I/O requests are passed all the way from the VFS/VM to the
driver and through the I/O scheduler. It even seems to work. :-)
* Added missing const to the iovec* parameter of the IORequest::Init()
methods.
* Disabled some debug output by default. Added new optional debug
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26692 a95241bf-73f2-0310-859d-f6bbb57e9c96

* We have to use get_memory_map_etc() instead of get_memory_map(), since
the scheduler thread doing that has no direct access to the
destination team's address space.
* Improved some debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26601 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed IOOperation::SetRequest() to Prepare().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26557 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Enabled all DMA tests, wrote some more.
* Moved data buffer creation to a TestSuiteContext class.
* Added checks if the I/O operation does the correct thing, ie. reads/writes
the data to the right offset.
* Rearranged DMA translation: we now handle the partial write case correctly
(bounce buffer must always span over the whole block), and are able to join
adjacent bounce buffers together.
* The new _AddBounceBuffer() method also respects boundary and segment size
restrictions for bounce buffers.
* IOOperation now prepares the outgoing vecs/offset/length to contain the
right data for the current phase (partial read begin/end/do-all); it will
also make sure that the lengths of the vecs are of the same size than the
whole request.
* All tests are now passed, the I/O request implementation seems to be ready
for integration now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26556 a95241bf-73f2-0310-859d-f6bbb57e9c96

axeld + bonefish:
More work on the I/O scheduler, more precisely mainly the DMAResource class:
* When splitting requests into operations, we're now able to flexibly mix
bounce buffer segments and the given physical vectors in a single
operation. This reduces the number of operations.
* Squashed several TODO and fleshed out more of the implementation.
* Added a test driver running unit tests. There are only a few tests yet,
but those pass.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26519 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish + axeld:
* Moved the old I/O scheduler code into the device manager, and replaced its
contents completely :-)
* Implemented the DMA and I/O requests/scheduler framework - for now in C++
only. It's a work in progress and not used anywhere yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26488 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource: mutex_lock() before calling mutex_destroy().

device_manager: init DMAResource::fScratchVecs.

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.

More 64-bit compilation/safety fixes.

Merged the signals branch into trunk, with these changes:
* The team and thread kernel structures have been renamed to Team and Thread
respectively and moved into the new BKernel namespace.
* Several (kernel add-on) sources have been converted from C to C++ since
private kernel headers are included that are no longer C compatible.

Changes after merging:
* Fixed gcc 2 build (warnings mainly in the scary firewire bus manager).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40196 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::Init(): Also evaluate the device node's B_DMA_LOW_ADDRESS and
B_DMA_HIGH_ADDRESS attributes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37143 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixed more address types related issues. Mostly printf() or comparison
warnings, but also some oversights from earlier changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37000 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced type generic_io_vec, which is similar to iovec, but uses types
that are wide enough for both virtual and physical addresses.
* DMABuffer, IORequest, IOScheduler,... and code using them: Use
generic_io_vec and generic_{addr,size}_t where necessary.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36997 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Changed physical_entry::{address,size} to phys_{addr,size}_t and changed
map_physical_memory()'s physicalAddress parameter type from void* to
phys_addr_t. This breaks source compatibility, but -- as long as
phys_{addr,size}_t remain 32 bit wide -- keeps binary compatibility with
BeOS.
* Adjusted all code using the affected interfaces (Oh what fun!). Added a few
TODOs in places where the wrong types (e.g. void* for physical addresses
are used). Looks like quite a few drivers aren't 64 bit safe and others
will break with PAE.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36960 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed src/system/kernel/device_manager/io_requests.{h,cpp} to
IORequest.{h,cpp}.
* Introduced public <io_requests.h> header. Currently it only declares the
single function BFS uses.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29446 a95241bf-73f2-0310-859d-f6bbb57e9c96

* DMAResource::TranslateNext(): Added parameter to limit the maximum
operation length.
* IORequest: Added owner (IORequestOwner). Also added a SetUnfinished()
method, which is invoked by the I/O scheduler after all operations of
the request have been finished, but the request isn't done yet.
* Added debugger commands "io_request_owner" and "io_scheduler" printing
information for a IORequestOwner and IOScheduler object respectively.
* Implemented an actual I/O scheduling algorithm. It's a simple round
robin strategy (a queue per thread) with a unidirectional elevator
serializing the operations. ATM priorities are ignored, the bandwidth
isn't adjusted to the device, and there are TODOs all over the place.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27216 a95241bf-73f2-0310-859d-f6bbb57e9c96

A DMABuffer doesn't have a fixed bounce buffer assigned anymore. We do
dynamically assign one when needed. Under the assumption that in most
cases a bounce buffer isn't needed, we can thus prepare a lot more
operations.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27185 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::TranslateNext(): Fixed several bugs that could cause too
many bytes to be read/written, which, among other things, could trigger
an assert in the IORequest code:
* In case of a partial (i.e. non-block-aligned) begin, transferLeft was
not adjusted correctly.
* The main loop was lacking a transferLeft check.
* Main loop: When finally using a bounce buffer, the unrestricted vec
length was used as base length for the bounce buffer.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27042 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Replaced the B_BLOCK_DEVICE_* defines with B_DMA_* defines that better match
our dma_restrictions structure (but we're using blocks instead of bytes,
since unlike the block size, the restrictions attributes are constant).
* We might want to use blocks for the dma_restrictions structure as well in
the future...
* Fixed another bug in the device_node variant of DMAResource::Init(): the max
segment size was specified in blocks as well.
* Removed the "hardcode" block_io module and header.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26973 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the mix of bufferCount vs. max_segment_count with regards to
B_BLOCK_DEVICE_MAX_SG_BLOCKS as pointed out by Ingo.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26972 a95241bf-73f2-0310-859d-f6bbb57e9c96

Another hard code (DMAResource::TranslateNext()) fix: In the write case
if after the main loop the transfer is already block aligned, we still
have to check whether the last vec is a bounce buffer that is shorter
than a complete block, but exceeds the original end of the request. If
so, we have to cut back to the previous block and add a block-sized
bounce buffer instead. Actually that's almost the same case as when the
transfer length is not yet block aligned, and thus we let the same code
handle it. Fixes bug #2584.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26910 a95241bf-73f2-0310-859d-f6bbb57e9c96

* When creating the physical vector array, we did not advance "base" in the
loop.
* This is probably the cause for file corruptions as well as bug #2595; will
have another look tomorrow.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26905 a95241bf-73f2-0310-859d-f6bbb57e9c96

DMAResource::TranslateNext(), in case of given physical vecs:
* segmentCount was potentially set incorrectly. It could be too big,
since we considered all vecs, not only those remaining.
* The main loop condition was incorrect. This would lead to too few
DMABuffer vecs (or none at all) for any but the first IOOperation of a
request. Should fix #2586.
* Correctly offset by vecIndex in debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26881 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added Dump() method to IORequest, IOOperation, IOBuffer, and DMABuffer.
* Added KDL commands "io_request", "io_operation", "io_buffer", and
"dma_buffer".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26838 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added a DMAResource::Init() method that gets a device node - for now, it will
reuse the block_io attributes in the node to build the dma_restrictions.
* DMAResource::Init() now dumps the dma_resources (should be done with the
TRACE() macro later).
* Turned off IOScheduler debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26825 a95241bf-73f2-0310-859d-f6bbb57e9c96

* It is now supported that I/O operations and requests are only handled
partially (e.g. due to hitting the end of file). The respective
classes have grown new methods and attributes to deal with that. The
"finished" callbacks have got additional parameters to indicate
whether the transfer was only partial and how much has been
transferred. Other callbacks and functions have a size_t* in/out
parameter instead of a simple size_t, now.
* vfs_{read,write}_pages() do now use the I/O request framework instead
of the underlying FS's {read,write}_pages() hooks (those should be
unused now). Furthermore they've got an additional "flags" parameter,
which is passed to IORequest::Init(), i.e. it allows to specify that
the given vecs refer to physical addresses.
* The file cache's read_into_cache() reads directly into physical
pages, now.
* Fixed bug in DoIO::IO(): The offset was not adjusted, so that all
pages were incorrectly transferred from/to the same location.
* Fixed broken subrequest scheduling loop head in
do_iterative_fd_io_iterate().
* Adjusted the test driver and implemented its io() hook. Using this
driver I/O requests are passed all the way from the VFS/VM to the
driver and through the I/O scheduler. It even seems to work. :-)
* Added missing const to the iovec* parameter of the IORequest::Init()
methods.
* Disabled some debug output by default. Added new optional debug
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26692 a95241bf-73f2-0310-859d-f6bbb57e9c96

* We have to use get_memory_map_etc() instead of get_memory_map(), since
the scheduler thread doing that has no direct access to the
destination team's address space.
* Improved some debug output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26601 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed IOOperation::SetRequest() to Prepare().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26557 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Enabled all DMA tests, wrote some more.
* Moved data buffer creation to a TestSuiteContext class.
* Added checks if the I/O operation does the correct thing, ie. reads/writes
the data to the right offset.
* Rearranged DMA translation: we now handle the partial write case correctly
(bounce buffer must always span over the whole block), and are able to join
adjacent bounce buffers together.
* The new _AddBounceBuffer() method also respects boundary and segment size
restrictions for bounce buffers.
* IOOperation now prepares the outgoing vecs/offset/length to contain the
right data for the current phase (partial read begin/end/do-all); it will
also make sure that the lengths of the vecs are of the same size than the
whole request.
* All tests are now passed, the I/O request implementation seems to be ready
for integration now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26556 a95241bf-73f2-0310-859d-f6bbb57e9c96

axeld + bonefish:
More work on the I/O scheduler, more precisely mainly the DMAResource class:
* When splitting requests into operations, we're now able to flexibly mix
bounce buffer segments and the given physical vectors in a single
operation. This reduces the number of operations.
* Squashed several TODO and fleshed out more of the implementation.
* Added a test driver running unit tests. There are only a few tests yet,
but those pass.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26519 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish + axeld:
* Moved the old I/O scheduler code into the device manager, and replaced its
contents completely :-)
* Implemented the DMA and I/O requests/scheduler framework - for now in C++
only. It's a work in progress and not used anywhere yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26488 a95241bf-73f2-0310-859d-f6bbb57e9c96