[PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

[Peter Maydell]

In aarch64_max_initfn() we update both 32-bit and 64-bit ID
registers.  The intended pattern is that for 64-bit ID registers we
use FIELD_DP64 and the uint64_t 't' register, while 32-bit ID
registers use FIELD_DP32 and the uint32_t 'u' register.  For
ID_AA64DFR0 we accidentally used 'u', meaning that the top 32 bits of
this 64-bit ID register would end up always zero.  Luckily at the
moment that's what they should be anyway, so this bug has no visible
effects.

Use the right-sized variable.

Fixes: 3bec78447a958d481991
Signed-off-by: Peter Maydell <address@hidden>
---
 target/arm/cpu64.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 95d0c8c101a..4c7105ea1a1 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -708,9 +708,9 @@ static void aarch64_max_initfn(Object *obj)
         u = FIELD_DP32(u, ID_MMFR4, CNP, 1); /* TTCNP */
         cpu->isar.id_mmfr4 = u;
 
-        u = cpu->isar.id_aa64dfr0;
-        u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
-        cpu->isar.id_aa64dfr0 = u;
+        t = cpu->isar.id_aa64dfr0;
+        t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
+        cpu->isar.id_aa64dfr0 = t;
 
         u = cpu->isar.id_dfr0;
         u = FIELD_DP32(u, ID_DFR0, PERFMON, 5); /* v8.4-PMU */
-- 
2.20.1