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

From: Shreyas B. Prabhu
Date: Mon Aug 25 2014 - 14:03:42 EST

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@xxxxxxxxxxxxxxxx
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Suggested-by: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Shreyas B. Prabhu <shreyas@xxxxxxxxxxxxxxxxxx>
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_HANDLE_HMI 98
+#define OPAL_SLW_SET_REG 100

@@ -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);

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