[PATCH 5/9] powerpc/powernv: Add OPAL call to save and restore

["Shreyas B. Prabhu" <shreyas@linux.vnet.ibm.com>]

PORE can be programmed to restore hypervisor registers when waking up
from deep cpu idle states like winkle.

Add call to pass SPR address and value to OPAL, which in turn will
program PORE to restore the register state.

Cc: linuxppc-dev@lists.ozlabs.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Suggested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/opal.h                | 2 ++
 arch/powerpc/platforms/powernv/opal-wrappers.S | 1 +
 2 files changed, 3 insertions(+)

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 166d572..d376020 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -150,6 +150,7 @@ struct opal_sg_list {
 #define OPAL_PCI_EEH_FREEZE_SET			97
 #define OPAL_HANDLE_HMI				98
 #define OPAL_CONFIG_IDLE_STATE			99
+#define OPAL_SLW_SET_REG			100
 #define OPAL_REGISTER_DUMP_REGION		101
 #define OPAL_UNREGISTER_DUMP_REGION		102
 
@@ -978,6 +979,7 @@ extern int opal_handle_hmi_exception(struct pt_regs *regs);
 extern void opal_shutdown(void);
 extern int opal_resync_timebase(void);
 int64_t opal_config_idle_state(uint64_t state, uint64_t enter);
+int64_t opal_slw_set_reg(uint64_t cpu_pir, uint64_t sprn, uint64_t val);
 
 extern void opal_lpc_init(void);
 
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 8d1e724..12e5d46 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -246,5 +246,6 @@ OPAL_CALL(opal_get_param,			OPAL_GET_PARAM);
 OPAL_CALL(opal_set_param,			OPAL_SET_PARAM);
 OPAL_CALL(opal_handle_hmi,			OPAL_HANDLE_HMI);
 OPAL_CALL(opal_config_idle_state,		OPAL_CONFIG_IDLE_STATE);
+OPAL_CALL(opal_slw_set_reg,			OPAL_SLW_SET_REG);
 OPAL_CALL(opal_register_dump_region,		OPAL_REGISTER_DUMP_REGION);
 OPAL_CALL(opal_unregister_dump_region,		OPAL_UNREGISTER_DUMP_REGION);
-- 
1.9.0