asm-generic: New generic ticket-based spinlock
This contains a new ticket-based spinlock that uses only generic
atomics and doesn't require as much from the memory system as qspinlock
does in order to be fair. It also includes a bit of documentation about
the qspinlock and qrwlock fairness requirements.
This will soon be used by a handful of architectures that don't meet the
qspinlock requirements.
asm-generic: qrwlock: Document the spinlock fairness requirements
I could only find the fairness requirements documented as the C code,
this calls them out in a comment just to be a bit more explicit.
Reviewed-by: Arnd Bergmann <arnd@arndb.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
1 file changed
