[PATCH v2 1/3] firmware: psci: Fix bind_smccc_features psci check

[Weizhao Ouyang]

According to PSCI specification DEN0022F, PSCI_FEATURES is used to check
whether the SMCCC is implemented by discovering SMCCC_VERSION.

Signed-off-by: Weizhao Ouyang <o451686892 at gmail.com>
---
v2: check SMCCC_ARCH_FEATURES
---
 drivers/firmware/psci.c   | 9 ++++++++-
 include/linux/arm-smccc.h | 6 ++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index c6b9efab41..ed701cd1e4 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -135,7 +135,7 @@ static int bind_smccc_features(struct udevice *dev, int psci_method)
 	    PSCI_VERSION_MAJOR(psci_0_2_get_version()) == 0)
 		return 0;
 
-	if (request_psci_features(ARM_SMCCC_ARCH_FEATURES) ==
+	if (request_psci_features(ARM_SMCCC_VERSION) ==
 	    PSCI_RET_NOT_SUPPORTED)
 		return 0;
 
@@ -144,6 +144,13 @@ static int bind_smccc_features(struct udevice *dev, int psci_method)
 	else
 		pdata->invoke_fn = smccc_invoke_smc;
 
+	/*
+	 * SMCCC_ARCH_FEATURES is MANDATORY from SMCCC v1.1, but we still remain
+	 * the invoke_fn() even the SMCCC version is v1.0.
+	 */
+	if (invoke_psci_fn(ARM_SMCCC_VERSION, 0, 0, 0) < ARM_SMCCC_VERSION_1_1)
+		return 0;
+
 	feature_cnt = ll_entry_count(struct arm_smccc_feature, arm_smccc_feature);
 	feature = ll_entry_start(struct arm_smccc_feature, arm_smccc_feature);
 
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index f44e9e8f93..da3d29aabe 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -55,8 +55,14 @@
 #define ARM_SMCCC_QUIRK_NONE		0
 #define ARM_SMCCC_QUIRK_QCOM_A6		1 /* Save/restore register a6 */
 
+#define ARM_SMCCC_VERSION		0x80000000
 #define ARM_SMCCC_ARCH_FEATURES		0x80000001
 
+#define ARM_SMCCC_VERSION_1_0		0x10000
+#define ARM_SMCCC_VERSION_1_1		0x10001
+#define ARM_SMCCC_VERSION_1_2		0x10002
+#define ARM_SMCCC_VERSION_1_3		0x10003
+
 #define ARM_SMCCC_RET_NOT_SUPPORTED	((unsigned long)-1)
 
 #ifndef __ASSEMBLY__
-- 
2.39.2