firmware: psci: bind arm smccc features when discovered

Use PSCI device to query Arm SMCCC v1.1 support from secure monitor
and if so, bind drivers for the SMCCC features that monitor supports.

Drivers willing to be bound from Arm SMCCC features discovery can use
macro ARM_SMCCC_FEATURE_DRIVER() to register to smccc feature discovery,
providing target driver name and a callback function that returns
whether or not the SMCCC feature is supported by the system.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

2 files changed, 30 insertions, 0 deletions

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 94a20c97937..e1d09884a1c 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -84,6 +84,22 @@ struct arm_smccc_quirk {
 };
 
 /**
+ * struct arm_smccc_feature - Driver registration data for discoverable feature
+ * @driver_name: name of the driver relate to the SMCCC feature
+ * @is_supported: callback to test if SMCCC feature is supported
+ */
+struct arm_smccc_feature {
+	const char *driver_name;
+	bool (*is_supported)(void (*invoke_fn)(unsigned long a0, unsigned long a1, unsigned long a2,
+					       unsigned long a3, unsigned long a4, unsigned long a5,
+					       unsigned long a6, unsigned long a7,
+					       struct arm_smccc_res *res));
+};
+
+#define ARM_SMCCC_FEATURE_DRIVER(__name) \
+	ll_entry_declare(struct arm_smccc_feature, __name, arm_smccc_feature)
+
+/**
  * __arm_smccc_smc() - make SMC calls
  * @a0-a7: arguments passed in registers 0 to 7
  * @res: result values from registers 0 to 3
diff --git a/include/linux/psci.h b/include/linux/psci.h
index c78c1079a82..03e41863432 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -11,6 +11,8 @@
 #ifndef _UAPI_LINUX_PSCI_H
 #define _UAPI_LINUX_PSCI_H
 
+#include <linux/arm-smccc.h>
+
 /*
  * PSCI v0.1 interface
  *
@@ -115,6 +117,18 @@
 #define PSCI_RET_DISABLED			-8
 #define PSCI_RET_INVALID_ADDRESS		-9
 
+/**
+ * struct psci_plat_data - PSCI driver platform data
+ * @method: Selected invocation conduit
+ */
+struct psci_plat_data {
+	void (*invoke_fn)(unsigned long arg0, unsigned long arg1,
+			  unsigned long arg2, unsigned long arg3,
+			  unsigned long arg4, unsigned long arg5,
+			  unsigned long arg6, unsigned long arg7,
+			  struct arm_smccc_res *res);
+};
+
 #ifdef CONFIG_ARM_PSCI_FW
 unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
 			     unsigned long a2, unsigned long a3);