[PATCH v10 10/10] arm: tcg: Adhere to SMCCC 1.3 section 5.2

[Alexander Graf <agraf@csgraf.de>]

The SMCCC 1.3 spec section 5.2 says

  The Unknown SMC Function Identifier is a sign-extended value of (-1)
  that is returned in the R0, W0 or X0 registers. An implementation must
  return this error code when it receives:

    * An SMC or HVC call with an unknown Function Identifier
    * An SMC or HVC call for a removed Function Identifier
    * An SMC64/HVC64 call from AArch32 state

To comply with these statements, let's always return -1 when we encounter
an unknown HVC or SMC call.

Signed-off-by: Alexander Graf <agraf@csgraf.de>

---

v8 -> v9:

  - Remove Windows specifics and just comply with SMCCC spec

v9 -> v10:

  - Fix comment
---
 target/arm/psci.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/target/arm/psci.c b/target/arm/psci.c
index 6709e28013..b279c0b9a4 100644
--- a/target/arm/psci.c
+++ b/target/arm/psci.c
@@ -27,15 +27,13 @@
 
 bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
 {
-    /* Return true if the r0/x0 value indicates a PSCI call and
-     * the exception type matches the configured PSCI conduit. This is
-     * called before the SMC/HVC instruction is executed, to decide whether
-     * we should treat it as a PSCI call or with the architecturally
+    /*
+     * Return true if the exception type matches the configured PSCI conduit.
+     * This is called before the SMC/HVC instruction is executed, to decide
+     * whether we should treat it as a PSCI call or with the architecturally
      * defined behaviour for an SMC or HVC (which might be UNDEF or trap
      * to EL2 or to EL3).
      */
-    CPUARMState *env = &cpu->env;
-    uint64_t param = is_a64(env) ? env->xregs[0] : env->regs[0];
 
     switch (excp_type) {
     case EXCP_HVC:
@@ -52,27 +50,7 @@ bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
         return false;
     }
 
-    switch (param) {
-    case QEMU_PSCI_0_2_FN_PSCI_VERSION:
-    case QEMU_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
-    case QEMU_PSCI_0_2_FN_AFFINITY_INFO:
-    case QEMU_PSCI_0_2_FN64_AFFINITY_INFO:
-    case QEMU_PSCI_0_2_FN_SYSTEM_RESET:
-    case QEMU_PSCI_0_2_FN_SYSTEM_OFF:
-    case QEMU_PSCI_0_1_FN_CPU_ON:
-    case QEMU_PSCI_0_2_FN_CPU_ON:
-    case QEMU_PSCI_0_2_FN64_CPU_ON:
-    case QEMU_PSCI_0_1_FN_CPU_OFF:
-    case QEMU_PSCI_0_2_FN_CPU_OFF:
-    case QEMU_PSCI_0_1_FN_CPU_SUSPEND:
-    case QEMU_PSCI_0_2_FN_CPU_SUSPEND:
-    case QEMU_PSCI_0_2_FN64_CPU_SUSPEND:
-    case QEMU_PSCI_0_1_FN_MIGRATE:
-    case QEMU_PSCI_0_2_FN_MIGRATE:
-        return true;
-    default:
-        return false;
-    }
+    return true;
 }
 
 void arm_handle_psci_call(ARMCPU *cpu)
@@ -194,10 +172,9 @@ void arm_handle_psci_call(ARMCPU *cpu)
         break;
     case QEMU_PSCI_0_1_FN_MIGRATE:
     case QEMU_PSCI_0_2_FN_MIGRATE:
+    default:
         ret = QEMU_PSCI_RET_NOT_SUPPORTED;
         break;
-    default:
-        g_assert_not_reached();
     }
 
 err:
-- 
2.30.1 (Apple Git-130)