- Emulate Linux mutex API using sx(9) locks with only exclusive operations
instead of mutex(9), in Linux mutexes are sleepable.
- Emulate Linux rwlock_t using rwlock(9) instead of sx(9). rwlock_t
in Linux are spin locks
- 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
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
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
If structure packed as __packed clang (and probably gcc) generates
code that loads word fields (e.g. tx_pos) byte-by-byte and if it's
modified by VideoCore in the same time as ARM loads the value result
is going to be mixed combination of bytes from previous value and
new one.
