Power9 CPUs have a core thread state register accessible via SPRC/SPRD
indirect registers. This register includes a bit for big-core mode,
which skiboot requires.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
target/ppc/misc_helper.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
index 692e48e6bc..e69236d2de 100644
--- a/target/ppc/misc_helper.c
+++ b/target/ppc/misc_helper.c
@@ -319,6 +319,23 @@ target_ulong helper_load_sprd(CPUPPCState *env)
case 0: /* SCRATCH0-3 */
case 1: /* SCRATCH4-7 */
return pc->scratch[(sprc >> 3) & 0x7];
+
+ case 0x1e0: /* core thread state */
+ if (env->excp_model == POWERPC_EXCP_POWER9) {
+ /*
+ * Only implement for POWER9 because skiboot uses it to check
+ * big-core mode. Other bits are unimplemented so we would
+ * prefer to get unimplemented message on POWER10 if it were
+ * used anywhere.
+ */
+ if (pc->big_core) {
+ return PPC_BIT(63);
+ } else {
+ return 0;
+ }
+ }
+ /* fallthru */
+
default:
qemu_log_mask(LOG_UNIMP, "mfSPRD: Unimplemented SPRC:0x"
TARGET_FMT_lx"\n", sprc);
--
2.45.1
