firmware: smccc: Refactor SMCCC specific bits into separate file

In order to add newer SMCCC v1.1+ functionality and to avoid cluttering
PSCI firmware driver with SMCCC bits, let us move the SMCCC specific
details under drivers/firmware/smccc/smccc.c

We can also drop conduit and smccc_version from psci_operations structure
as SMCCC was the sole user and now it maintains those.

No functionality change in this patch though.

Signed-off-by: Sudeep Holla <[e-mail]>
Tested-by: Etienne Carriere <[e-mail]>
Reviewed-by: Etienne Carriere <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

MAINTAINERS

···
 S:	Odd Fixes
 F:	drivers/net/ethernet/smsc/smc91x.*
 
+SECURE MONITOR CALL(SMC) CALLING CONVENTION (SMCCC)
+M:	Mark Rutland <[e-mail]>
+M:	Lorenzo Pieralisi <[e-mail]>
+M:	Sudeep Holla <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	drivers/firmware/smccc/
+F:	include/linux/arm-smccc.h
+
 SMIA AND SMIA++ IMAGE SENSOR DRIVER
 M:	Sakari Ailus <[e-mail]>
 L:	[e-mail]

drivers/firmware/Makefile

···
 obj-$(CONFIG_TURRIS_MOX_RWTM)	+= turris-mox-rwtm.o
 
 obj-$(CONFIG_ARM_SCMI_PROTOCOL)	+= arm_scmi/
-obj-y				+= psci/
 obj-y				+= broadcom/
 obj-y				+= meson/
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
 obj-$(CONFIG_EFI)		+= efi/
 obj-$(CONFIG_UEFI_CPER)		+= efi/
 obj-y				+= imx/
+obj-y				+= psci/
+obj-y				+= smccc/
 obj-y				+= tegra/
 obj-y				+= xilinx/

drivers/firmware/psci/psci.c

···
  * require cooperation with a Trusted OS driver.
  */
 static int resident_cpu = -1;
+struct psci_operations psci_ops;
+static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
 
 bool psci_tos_resident_on(int cpu)
 {
 	return cpu == resident_cpu;
-}
-
-struct psci_operations psci_ops = {
-	.conduit = SMCCC_CONDUIT_NONE,
-	.smccc_version = ARM_SMCCC_VERSION_1_0,
-};
-
-enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
-{
-	if (psci_ops.smccc_version < ARM_SMCCC_VERSION_1_1)
-		return SMCCC_CONDUIT_NONE;
-
-	return psci_ops.conduit;
 }
 
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
···
 
 static u32 psci_cpu_suspend_feature;
 static bool psci_system_reset2_supported;
+void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit);
 
 static inline bool psci_has_ext_power_state(void)
 {
···
 		WARN(1, "Unexpected PSCI conduit %d\n", conduit);
 	}
 
-	psci_ops.conduit = conduit;
+	psci_conduit = conduit;
 }
 
 static int get_set_conduit_method(struct device_node *np)
···
 		u32 ret;
 		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
 		if (ret >= ARM_SMCCC_VERSION_1_1) {
-			psci_ops.smccc_version = ret;
+			arm_smccc_version_init(ret, psci_conduit);
 			ver = ret;
 		}
 	}

drivers/firmware/smccc/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+#
+obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o

drivers/firmware/smccc/smccc.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "smccc: " fmt
+
+#include <linux/init.h>
+#include <linux/arm-smccc.h>
+
+static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
+static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
+
+void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
+{
+	smccc_version = version;
+	smccc_conduit = conduit;
+}
+
+enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
+{
+	if (smccc_version < ARM_SMCCC_VERSION_1_1)
+		return SMCCC_CONDUIT_NONE;
+
+	return smccc_conduit;
+}

include/linux/psci.h

···
 	int (*affinity_info)(unsigned long target_affinity,
 			unsigned long lowest_affinity_level);
 	int (*migrate_info_type)(void);
-	enum arm_smccc_conduit conduit;
-	u32 smccc_version;
 };
 
 extern struct psci_operations psci_ops;