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>
---
 target/ppc/cpu.h         |  8 ++++----
 target/ppc/helper_regs.c | 10 +++++-----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index a44de22ca4..16baea609c 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1750,8 +1750,8 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_USPRG5            (0x105)
 #define SPR_USPRG6            (0x106)
 #define SPR_USPRG7            (0x107)
-#define SPR_VTBL              (0x10C)
-#define SPR_VTBU              (0x10D)
+#define SPR_TBL               (0x10C)
+#define SPR_TBU               (0x10D)
 #define SPR_SPRG0             (0x110)
 #define SPR_SPRG1             (0x111)
 #define SPR_SPRG2             (0x112)
@@ -1764,8 +1764,8 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_SPRG7             (0x117)
 #define SPR_ASR               (0x118)
 #define SPR_EAR               (0x11A)
-#define SPR_TBL               (0x11C)
-#define SPR_TBU               (0x11D)
+#define SPR_WR_TBL            (0x11C)
+#define SPR_WR_TBU            (0x11D)
 #define SPR_TBU40             (0x11E)
 #define SPR_SVR               (0x11E)
 #define SPR_BOOKE_PIR         (0x11E)
diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
index 8f5bd1536e..94c9a5a5c1 100644
--- a/target/ppc/helper_regs.c
+++ b/target/ppc/helper_regs.c
@@ -461,22 +461,22 @@ void register_generic_sprs(PowerPCCPU *cpu)
 
     /* Time base */
 #if defined(TARGET_PPC64)
-    spr_register(env, SPR_VTBL,  "TB",
+    spr_register(env, SPR_TBL, "TB",
 #else
-    spr_register(env, SPR_VTBL,  "TBL",
+    spr_register(env, SPR_TBL, "TBL",
 #endif
                  &spr_read_tbl, SPR_NOACCESS,
                  &spr_read_tbl, SPR_NOACCESS,
                  0x00000000);
-    spr_register(env, SPR_TBL,   "TBL",
+    spr_register(env, SPR_WR_TBL, "TBL",
                  &spr_read_tbl, SPR_NOACCESS,
                  &spr_read_tbl, &spr_write_tbl,
                  0x00000000);
-    spr_register(env, SPR_VTBU,  "TBU",
+    spr_register(env, SPR_TBU, "TBU",
                  &spr_read_tbu, SPR_NOACCESS,
                  &spr_read_tbu, SPR_NOACCESS,
                  0x00000000);
-    spr_register(env, SPR_TBU,   "TBU",
+    spr_register(env, SPR_WR_TBU, "TBU",
                  &spr_read_tbu, SPR_NOACCESS,
                  &spr_read_tbu, &spr_write_tbu,
                  0x00000000);
-- 
2.42.0