[sync] Apply C API rubric to libsync

Test: No behavior change
Change-Id: I30a413f7fb5d3f4e741e5204532b82e73595c086

[drivers][bti] Use zx_bti_pin instead of zx_bti_pin_new

This should be a no-op, since these are aliases.

ZX-1936 #comment Switch drivers to new syscall name

Change-Id: I09e5a5fd48b7d4539347564897f14fab90e19868

[dev][virtio] Migrate to new BTI interface

Now with PMTs!

ZX-1936 #comment migrated virtio

Change-Id: I57df8a19eb5622ea82ff11a1a3d73bb25bd4327a

[ddk][io-buffer] Rename callsites of io_buffer_init*_with_bti

ZX-1804 #comment Move all zircon callsites to final name

Change-Id: Ie35de5654841e84653582126dc1f976664c0f49d

[virtio] Convert use of OP_LOOKUP to bti_pin

Change-Id: I828fef091de454e3dd7d21d2964beb5c20ef879b

[virtio] Make use of BTIs in io_buffer_init calls

Change-Id: Iae64c006045fcd465287d716dc1711d5923eaff2

[virtio] Wire BTIs through to the device objects

Change-Id: I8a19733734b8694f734463dd3134b77a9ae50d14

[virtio] Get rid of unused utilities file

Change-Id: If81c1f6e3441524479c191ae52037fb9c777781c

[virtio] Convert BlockDevice to use io_buffer

Change-Id: I0a22b9ec61e1e4083e89c4ce43b2549fff052cf4

[ddk][block] rename BLOCK_CORE protocol to BLOCK_IMPL

Change-Id: Iba98a01e526cffc01940fdbb1ea4c593f0f77184

[dev][virtio-block] add an external mutex around the ring descriptor

TODO: probably move the mutex into the ring class, but need to test
other devices for this.

ZX-1784 #done

Change-Id: I57c4b6e0a3bc8416faabd73c93d99b1f7fe77d04

[ddk][block] change device_rebind() semantics

Previously device_rebind() would call device_remove() on all of
the children of the device it was called on, *without* invoking
their unbind() hook, in violation of the device model.

Change this so that it instead causes all children to be unbound
and, then, when all those children are finally removed and eventually
released, *then* cause the rebind attempt.

This preserves the device model and further ensures that new children
do not get bound until the existing children are fully destructed.

Since all block protocol devices are accessed from userspace via the
shared block driver, instead of having the shared block driver forward
the BLOCK_RR_PART ioctl() to its parent, it fields this ioctl() itself,
causing its children to become unbound and the rebound.

One interesting change is that it no longer changes name -- if you RR_PART
against /dev/class/block/123, that device will persist (since it *is*
the same device, it's just that you asked for it to remove its children
and try again because its partition table may have changed, etc).

Currently we synthesize a REMOVE and ADD directory watch event for a
device being rebound. We should instead just generate a MODIFY event,
but that will require changes to various clients (block-watcher, tests, etc)
That depend on the old behavior.

Handling of BLOCK_RR_PART is removed from all block core drivers.

Change-Id: I9fd40ec11c216e3d2e0e88ef65ccd23e031eb245

[virtio][block] cope with temporary resource exhaustion

Don't fail if all 32 requests are in flight or there are
not enough free descriptor slots available. Instead wait
and try again as in-flight requests complete.

This could probably be done more cleverly, but for now
I avoided getting tricky.

Also, access alloc/free_blk_req() and the txn_list under
a lock, to avoid the irq thread and queueing threads
messing with each other.

Change-Id: I1d7f6e6e772c665514cddccd867520f56a3002b4

[virtio][block] convert to new block protocol

This works with the iochk exerciser, but does not pass the minfs
test. However the pre-conversion version fails the minfs test the
same way: if requests arrive fast enough there may not be enough
ring entries for a request and the driver does not have a mechanism
to wait until they become available.

Change-Id: I0d92774efbdf1ae1caa1d7359b6a3084047e7494

[block] Larger-than-device requests should fail, not truncate

ZX-1545 #comment In Progress

Change-Id: I456c71c1b093791d1e21855849d566726a4c0544

[virtio][block] Fix block request flags.

We need to ensure the write flag is cleared on the header of a recycled
block request. This fixes an assert in QEMU.

Change-Id: Id458870adbfba5314aa2686dfec852435862f4f9

[dev][block] Drastically simplify BLOCK_CORE protocol

Observations:
- Almost every block device driver implements the protocol
functions (set_callbacks, get_info, read, write) using
nearly identical code.
- The only differences which exist in those functions are
within the read/write functions, which may do additional
boundary checking. However, this boundary checking is
already accomplished by iotxn_queue, so it is redundant.

Exploiting these Observations:
- Relocate the iotxn allocating / enqueueing functionality
into the generic block driver, so it can be shared by
all block device drivers registered as BLOCK_CORE.
- In doing so, there is no longer a need for registered
callbacks. This simplifies block device drivers further.

Change-Id: I795418489cebd3ecebcb2d1153f1cfd7dcc77d5c

[dev][block] Add write barriers for groups of block iotxns

ZX-1436 #comment In Progress

Change-Id: Iaea7b796e3d073780bfead6bdc2a7c30bb29e491

[virtio] Refactor virtio backend support

- Implement device backends for transport rather than having
it be a part of the device class itself. These backends are
plugged into the device class to provide an abstraction between
device level interfaces and the specific nuances around the
virtio interface.
- Implement a legacy virtio bar0 PIO interface for use in systems
that only provide Virtio 0.9.5 devices.
- Move logging away from VIRTIO_ERROR and use newer ddk zxlogf.
- Run clang-fmt and clean up small nits here and there.
Change-Id: I2568e9554378163f19b89537986e0d5ea8b47510

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[zircon][mxtl->fbl] Rename mxtl to fbl

Change-Id: Ie21b6498e1bfb0a7fa0315e40b9e5c3ee78646be

[virtio] Minor tracing enhancement

This CL just improves the debug print routine for virtqueue descriptors.

In particular, originally this code:
\#if LOCAL_TRACE > 0
virtio_dump_desc(desc);
\#endif

would yield:
[00015.387] 02151.02581> vring descriptor 0x6fbd384f71f0:
addr 0x4a18600 len 0x465 flags 0000 next 0000

Now, this code:
LTRACE_DO(virtio_dump_desc(desc));

yields:
[00015.387] 02151.02581> vring descriptor 0x6fbd384f71f0:
[addr=0x4a18600, len=1125, flags=0000, next=0000]

Change-Id: I33c1dbe76038b1c132baf65f4a45b67632ff3f52

[virtio] Move more block structures to ulib.

This allows us to reuse these constants and structures for the
hypervisor.

Change-Id: I4d5c4bb512c11f97e82cf739f9b42f87bbfeda16

[dev][hifi][virtio][misc] Use MX_OK and MX_ERR_*

Change-Id: I24028af1027df43053be4d5b53150a19eab3ad6d

[ddk][block] new protocol support (3 of n)

Convert MX_PROTOCOL_BLOCK_CORE providers and consumers to the
new style protocol interface.

Change-Id: I3c2b190bade3cb18bfe6b32027715554a74dcf98

[udev][virtio] Move to system/dev/bus/

Change-Id: If774aaef5040c31b6ee76dad1aa8bac30165f045