[PATCH] powerpc/pseries: Add FW_FEATURE_PLPKS feature flag

[Andrew Donnellan]

Add a firmware feature flag, FW_FEATURE_PLPKS, to indicate availability of
Platform KeyStore related hcalls.

Check this flag in plpks_is_available() and pseries_plpks_init() before
trying to make an hcall.

Suggested-by: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Andrew Donnellan <a...@linux.ibm.com>
---
 arch/powerpc/include/asm/firmware.h       | 4 +++-
 arch/powerpc/platforms/pseries/firmware.c | 1 +
 arch/powerpc/platforms/pseries/plpks.c    | 5 ++++-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/firmware.h 
b/arch/powerpc/include/asm/firmware.h
index ed6db13a1d7c..69ae9cf57d50 100644
--- a/arch/powerpc/include/asm/firmware.h
+++ b/arch/powerpc/include/asm/firmware.h
@@ -56,6 +56,7 @@
 #define FW_FEATURE_FORM2_AFFINITY ASM_CONST(0x0000020000000000)
 #define FW_FEATURE_ENERGY_SCALE_INFO ASM_CONST(0x0000040000000000)
 #define FW_FEATURE_WATCHDOG    ASM_CONST(0x0000080000000000)
+#define FW_FEATURE_PLPKS       ASM_CONST(0x0000100000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -77,7 +78,8 @@ enum {
                FW_FEATURE_DRC_INFO | FW_FEATURE_BLOCK_REMOVE |
                FW_FEATURE_PAPR_SCM | FW_FEATURE_ULTRAVISOR |
                FW_FEATURE_RPT_INVALIDATE | FW_FEATURE_FORM2_AFFINITY |
-               FW_FEATURE_ENERGY_SCALE_INFO | FW_FEATURE_WATCHDOG,
+               FW_FEATURE_ENERGY_SCALE_INFO | FW_FEATURE_WATCHDOG |
+               FW_FEATURE_PLPKS,
        FW_FEATURE_PSERIES_ALWAYS = 0,
        FW_FEATURE_POWERNV_POSSIBLE = FW_FEATURE_OPAL | FW_FEATURE_ULTRAVISOR,
        FW_FEATURE_POWERNV_ALWAYS = 0,
diff --git a/arch/powerpc/platforms/pseries/firmware.c 
b/arch/powerpc/platforms/pseries/firmware.c
index 080108d129ed..18447e5fa17d 100644
--- a/arch/powerpc/platforms/pseries/firmware.c
+++ b/arch/powerpc/platforms/pseries/firmware.c
@@ -68,6 +68,7 @@ hypertas_fw_features_table[] = {
        {FW_FEATURE_RPT_INVALIDATE,     "hcall-rpt-invalidate"},
        {FW_FEATURE_ENERGY_SCALE_INFO,  "hcall-energy-scale-info"},
        {FW_FEATURE_WATCHDOG,           "hcall-watchdog"},
+       {FW_FEATURE_PLPKS,              "hcall-pks"},
 };
 
 /* Build up the firmware features bitmask using the contents of
diff --git a/arch/powerpc/platforms/pseries/plpks.c 
b/arch/powerpc/platforms/pseries/plpks.c
index 6f7bf3fc3aea..b0658ea3eccb 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -378,7 +378,7 @@ bool plpks_is_available(void)
 {
        int rc;
 
-       if (!firmware_has_feature(FW_FEATURE_LPAR))
+       if (!firmware_has_feature(FW_FEATURE_PLPKS))
                return false;
 
        rc = _plpks_get_config();
@@ -690,6 +690,9 @@ static __init int pseries_plpks_init(void)
 {
        int rc;
 
+       if (!firmware_has_feature(FW_FEATURE_PLPKS))
+               return -ENODEV;
+
        rc = _plpks_get_config();
 
        if (rc) {
-- 
2.39.2