[PATCH 16/17] firmware: qcom_scm: Enable legacy calling convention in qcom_scm-64.c

[Elliot Berman <eberman@xxxxxxxxxxxxxx>]

Enable legacy calling convention in qcom_scm-64. Update
is_call_available to use legacy function numbers when using legacy
convention.

Signed-off-by: Elliot Berman <eberman@xxxxxxxxxxxxxx>
---
 drivers/firmware/qcom_scm-64.c | 43 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index 7bb68f2..355d9d7 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -60,6 +60,7 @@ struct arm_smccc_args {
 
 enum qcom_smc_convention {
 	SMC_CONVENTION_UNKNOWN,
+	SMC_CONVENTION_LEGACY,
 	SMC_CONVENTION_ARM_32,
 	SMC_CONVENTION_ARM_64,
 };
@@ -415,7 +416,16 @@ static int qcom_scm_call_atomic_legacy(struct device *dev,
 static int qcom_scm_call(struct device *dev, struct qcom_scm_desc *desc)
 {
 	might_sleep();
-	return qcom_scm_call_smccc(dev, desc, false);
+	switch (qcom_smc_convention) {
+	case SMC_CONVENTION_ARM_32:
+	case SMC_CONVENTION_ARM_64:
+		return qcom_scm_call_smccc(dev, desc, false);
+	case SMC_CONVENTION_LEGACY:
+		return qcom_scm_call_legacy(dev, desc);
+	default:
+		pr_err("Unknown current SCM calling convention.\n");
+		return -EINVAL;
+	}
 }
 
 /**
@@ -431,7 +441,16 @@ static int qcom_scm_call(struct device *dev, struct qcom_scm_desc *desc)
  */
 static int qcom_scm_call_atomic(struct device *dev, struct qcom_scm_desc *desc)
 {
-	return qcom_scm_call_smccc(dev, desc, true);
+	switch (qcom_smc_convention) {
+	case SMC_CONVENTION_ARM_32:
+	case SMC_CONVENTION_ARM_64:
+		return qcom_scm_call_smccc(dev, desc, true);
+	case SMC_CONVENTION_LEGACY:
+		return qcom_scm_call_atomic_legacy(dev, desc);
+	default:
+		pr_err("Unknown current SCM calling convention.\n");
+		return -EINVAL;
+	}
 }
 
 #define QCOM_SCM_FLAG_COLDBOOT_CPU0	0x00
@@ -750,8 +769,19 @@ int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
 	};
 
 	desc.arginfo = QCOM_SCM_ARGS(1);
-	desc.args[0] = SMCCC_FUNCNUM(svc_id, cmd_id) |
-			(ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT);
+	switch (qcom_smc_convention) {
+	case SMC_CONVENTION_ARM_32:
+	case SMC_CONVENTION_ARM_64:
+		desc.args[0] = SMCCC_FUNCNUM(svc_id, cmd_id) |
+				(ARM_SMCCC_OWNER_SIP << ARM_SMCCC_OWNER_SHIFT);
+		break;
+	case SMC_CONVENTION_LEGACY:
+		desc.args[0] = LEGACY_FUNCNUM(svc_id, cmd_id);
+		break;
+	default:
+		pr_err("Unknown SMC convention being used\n");
+		return -EINVAL;
+	}
 
 	ret = qcom_scm_call(dev, &desc);
 
@@ -898,6 +928,11 @@ int __qcom_scm_qsmmu500_wait_safe_toggle(struct device *dev, bool en)
 
 void __qcom_scm_init(void)
 {
+	qcom_smc_convention = SMC_CONVENTION_LEGACY;
+	if (__qcom_scm_is_call_available(NULL, QCOM_SCM_SVC_INFO,
+			QCOM_SCM_INFO_IS_CALL_AVAIL) == 1)
+		goto out;
+
 	qcom_smc_convention = SMC_CONVENTION_ARM_64;
 	if (__qcom_scm_is_call_available(NULL, QCOM_SCM_SVC_INFO,
 			QCOM_SCM_INFO_IS_CALL_AVAIL) == 1)
-- 
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