sim,kern: support FUTEX_WAIT_BITSET and FUTEX_WAKE_BITSET ops

This patch adds support for two operations in futex system call:
FUTEX_WAIT_BITSET and FUTEX_WAKE_BITSET. The two operations are used to
selectively wake up a certain thread waiting on a futex variable.

Basically each thread waiting on a futex variable is associated with a
bitset that is checked when another thread tries to wake up all threads
waiting on the futex variable.

Change-Id: I2300e53b144d8fae226423fa2efb0238c1d93ef9
Reviewed-on: https://gem5-review.googlesource.com/c/9621
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
3 files changed