[Qemu-devel] [PATCH v4 10/21] target-arm: A64: Introduce aarch64_banked_spsr_index()

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

Add aarch64_banked_spsr_index(), used to map an Exception Level
to an index in the banked_spsr array.

Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 target-arm/helper-a64.c |  2 +-
 target-arm/internals.h  | 14 ++++++++++++++
 target-arm/op_helper.c  |  3 ++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c
index b8e6d56..b970fd1 100644
--- a/target-arm/helper-a64.c
+++ b/target-arm/helper-a64.c
@@ -488,7 +488,7 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
     }
 
     if (is_a64(env)) {
-        env->banked_spsr[0] = pstate_read(env);
+        env->banked_spsr[aarch64_banked_spsr_index(1)] = pstate_read(env);
         env->sp_el[arm_current_pl(env)] = env->xregs[31];
         env->xregs[31] = env->sp_el[1];
         env->elr_el[1] = env->pc;
diff --git a/target-arm/internals.h b/target-arm/internals.h
index d63a975..c9897c2 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -75,6 +75,20 @@ static inline void arm_log_exception(int idx)
  */
 #define GTIMER_SCALE 16
 
+/*
+ * For AArch64, map a given EL to an index in the banked_spsr array.
+ */
+static inline unsigned int aarch64_banked_spsr_index(unsigned int el)
+{
+    static const unsigned int map[4] = {
+        [1] = 0, /* EL1.  */
+        [2] = 6, /* EL2.  */
+        [3] = 7, /* EL3.  */
+    };
+    assert(el >= 1 && el <= 3);
+    return map[el];
+}
+
 int bank_number(int mode);
 void switch_mode(CPUARMState *, int);
 void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu);
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index f120b02..c2b4bf0 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -386,7 +386,8 @@ void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm)
 
 void HELPER(exception_return)(CPUARMState *env)
 {
-    uint32_t spsr = env->banked_spsr[0];
+    unsigned int spsr_idx = aarch64_banked_spsr_index(1);
+    uint32_t spsr = env->banked_spsr[spsr_idx];
     int new_el, i;
 
     if (env->pstate & PSTATE_SP) {
-- 
1.8.3.2