Searched hist:c8fd8373 (Results 1 – 1 of 1) sorted by relevance
| /openbmc/qemu/target/ppc/ |
| H A D | translate.c | c8fd8373 Wed Jun 06 02:33:53 CDT 2018 Cédric Le Goater <clg@kaod.org> target/ppc: extend eieio for POWER9
POWER9 introduced a new variant of the eieio instruction using bit 6
as a hint to tell the CPU it is a store-forwarding barrier.
The usage of this eieio extension was recently added in Linux 4.17
which activated the "support for a store forwarding barrier at kernel
entry/exit".
Unfortunately, it is not possible to insert this new eieio instruction
without considerable change in ppc_tr_translate_insn(). So instead we
loosen the QEMU eieio instruction mask and modify the gen_eieio()
helper to test for bit6. On non-POWER9 CPUs, the bit6 is just ignored
but a warning is emitted as this is not an instruction software should
be using.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
|