tree 7f98128b114fe044426610f39d925d1317cfbb72
parent 19e81ce51e68d9a1e6a317cd3f3e519757d16dfd
author Nicholas Piggin <npiggin@gmail.com> 1694579048 +1000
committer Nicholas Piggin <npiggin@gmail.com> 1708694683 +1000

target/ppc: Improve timebase register defines naming

The timebase in ppc started out with the mftb instruction which is like
mfspr but addressed timebase registers (TBRs) rather than SPRs. These
instructions could be used to read TB and TBU at 268 and 269. Timebase
could be written via the TBL and TBU SPRs at 284 and 285.

The ISA changed around v2.03 to bring TB and TBU reads into the SPR
space at 268 and 269 (access via mftb TBR-space is still supported
but will be phased out). Later, VTB was added which is an entirely
different register.

The SPR number defines in QEMU are understandably inconsistently named.
Change SPR 268, 269, 284, 285 to TBL, TBU, WR_TBL, WR_TBU, respectively.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>