MFC r323981
Modernize the use of vm_page_unwire(). Since r288122, vm_page_unwire()
has returned TRUE when the wire count transitions to zero, eliminating
the need for callers to inspect the page's wire count.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

ARM: Use new ARMv6 naming conventions for cache and TLB functions
in all but ARMv4 specific files.
Expand ARMv6 compatibility stubs in cpu-v4.h. Use physical address
in L2 cache functions if ARM_L2_PIPT is defined.

Fix slots DMA memory handling. It's similar to r290553.

Discussed with: gonzo
Approved by: kib (mentor)

Fix pagelist bus_dmamap_t map handling. Memory for pagelist is allocated
by bus_dmamem_alloc() which creates associated bus_dmamap_t map for us.
When this memory is freed by bus_dmamem_free(), the map is freed as well.

Thus there is no need to free it explicitly by bus_dmamap_destroy(),
which leads to double freeing.

Discussed with: gonzo
Approved by: kib (mentor)

Fix cache issues with bulk transfers

- Use pmap_quick_enter_page/pmap_quick_remove_page to bounce non-cacheline
aligned head and tail fragments
- Switch from static fragment size to configurable one, newer firmware
passes cache line size as cache_line_size DTB parameter.

With these changes both RPi and RPi2 pass functinal part of vchiq_test

Synchronize with latest upstream VCHI code:

- Add LIB_VERSION ioctl
- Add CLOSE_DELIVERED ioctl
- Bump code version

Upstream version: 3782f2ad42c08f4d32f64138f8be7341afc380f5

Fix BULK read transfer if destination buffer is not cache line-aligned.

We can't use copyout because destination memory is userland address
in another process but we have reference to respective page so map
the page into kernel address space and copy fragments there

- Perform bus_dmamap_sync on pagelist structure
- Wire pages of bulk transfer buffer when preparing pagelist

Remove unused variables

Import VCHI driver for Broadcom's VideoCore IV GPU

Differential Revision: D1753