target-arm: add emulation of PSCI calls for system emulation

Add support for handling PSCI calls in system emulation. Both version
0.1 and 0.2 of the PSCI spec are supported. Platforms can enable support
by setting the "psci-conduit" QOM property on the cpus to SMC or HVC
emulation and having a PSCI binding in their dtb.

Signed-off-by: Rob Herring <rob.herring@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-7-git-send-email-peter.maydell@linaro.org
[PMM: made system reset/off PSCI functions power down the CPU so
 we obey the PSCI API requirement never to return from them;
 rearranged how the code is plumbed into the exception system,
 so that we split "is this a valid call?" from "do the call"]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/target-arm/internals.h b/target-arm/internals.h
index e46de71..51c5c16 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -366,4 +366,16 @@ void hw_breakpoint_update_all(ARMCPU *cpu);
 /* Callback function for when a watchpoint or breakpoint triggers. */
 void arm_debug_excp_handler(CPUState *cs);
 
+#ifdef CONFIG_USER_ONLY
+static inline bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
+{
+    return false;
+}
+#else
+/* Return true if the r0/x0 value indicates that this SMC/HVC is a PSCI call. */
+bool arm_is_psci_call(ARMCPU *cpu, int excp_type);
+/* Actually handle a PSCI call */
+void arm_handle_psci_call(ARMCPU *cpu);
+#endif
+
 #endif