powerpc/powernv: Add OPAL check token call

Currently there is no way to generically check if an OPAL call exists or not
from the host kernel.

This adds an OPAL call opal_check_token() which tells you if the given token is
present in OPAL or not.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/opal.h

@@ -135,6 +135,7 @@ struct opal_sg_list {
 #define OPAL_FLASH_MANAGE			77
 #define OPAL_FLASH_UPDATE			78
 #define OPAL_RESYNC_TIMEBASE			79
+#define OPAL_CHECK_TOKEN			80
 #define OPAL_DUMP_INIT				81
 #define OPAL_DUMP_INFO				82
 #define OPAL_DUMP_READ				83
@@ -887,6 +888,7 @@ int64_t opal_pci_next_error(uint64_t phb_id, __be64 *first_frozen_pe,
 			    __be16 *pci_error_type, __be16 *severity);
 int64_t opal_pci_poll(uint64_t phb_id);
 int64_t opal_return_cpu(void);
+int64_t opal_check_token(uint64_t token);
 int64_t opal_reinit_cpus(uint64_t flags);
 
 int64_t opal_xscom_read(uint32_t gcid, uint64_t pcb_addr, __be64 *val);

arch/powerpc/platforms/powernv/opal-wrappers.S

@@ -232,6 +232,7 @@ OPAL_CALL(opal_validate_flash,			OPAL_FLASH_VALIDATE);
 OPAL_CALL(opal_manage_flash,			OPAL_FLASH_MANAGE);
 OPAL_CALL(opal_update_flash,			OPAL_FLASH_UPDATE);
 OPAL_CALL(opal_resync_timebase,			OPAL_RESYNC_TIMEBASE);
+OPAL_CALL(opal_check_token,			OPAL_CHECK_TOKEN);
 OPAL_CALL(opal_dump_init,			OPAL_DUMP_INIT);
 OPAL_CALL(opal_dump_info,			OPAL_DUMP_INFO);
 OPAL_CALL(opal_dump_info2,			OPAL_DUMP_INFO2);