[kernel][psci] add hook to call the SYSTEM_RESET2 psci call directly

Used to pass specific reset arguments through the call, which is
currently not possible.

Change-Id: Ib300c5ea538a0d8b266b73faa954d4e5dc84d04a
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1053868
Reviewed-by: Will Drewry <drewry@google.com>
Commit-Queue: Travis Geiselbrecht <travisg@google.com>

Author: travisg

zircon/kernel/dev/psci/include/dev/psci.h

@@ -78,4 +78,7 @@ zx::result<power_cpu_state> psci_get_cpu_state(uint64_t mpid);
 zx_status_t psci_system_off();
 zx_status_t psci_system_reset(power_reboot_flags flags);
 
+// Used when calling SYSTEM_RESET2 directly
+zx_status_t psci_system_reset2_raw(uint32_t reset_type, uint32_t cookie);
+
 #endif  // ZIRCON_KERNEL_DEV_PSCI_INCLUDE_DEV_PSCI_H_

zircon/kernel/dev/psci/psci.cc

@@ -107,6 +107,16 @@ uint32_t psci_get_feature(uint32_t psci_call) {
   return (uint32_t)do_psci_call(PSCI64_PSCI_FEATURES, psci_call, 0, 0);
 }
 
+zx_status_t psci_system_reset2_raw(uint32_t reset_type, uint32_t cookie) {
+  dprintf(INFO, "PSCI SYSTEM_RESET2: %#" PRIx32 " %#" PRIx32 "\n", reset_type, cookie);
+
+  uint64_t psci_status = do_psci_call(PSCI64_SYSTEM_RESET2, reset_type, cookie, 0);
+
+  dprintf(INFO, "PSCI SYSTEM_RESET2 returns %" PRIi64 "\n", static_cast<int64_t>(psci_status));
+
+  return psci_status_to_zx_status(psci_status);
+}
+
 zx_status_t psci_system_reset(power_reboot_flags flags) {
   uint64_t* args = reboot_args;