5 files changed, 262 insertions, 0 deletions
diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig
new file mode 100644
index 0000000000..15e7466179
--- /dev/null
+++ b/drivers/firmware/smccc/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HAVE_ARM_SMCCC
+	bool
+	help
+	  Include support for the Secure Monitor Call (SMC) and Hypervisor
+	  Call (HVC) instructions on Armv7 and above architectures.
+
+config HAVE_ARM_SMCCC_DISCOVERY
+	bool
+	depends on ARM_PSCI_FW
+	default y
+	help
+	 SMCCC v1.0 lacked discoverability and hence PSCI v1.0 was updated
+	 to add SMCCC discovery mechanism though the PSCI firmware
+	 implementation of PSCI_FEATURES(SMCCC_VERSION) which returns
+	 success on firmware compliant to SMCCC v1.1 and above.
+
+config ARM_SMCCC_SOC_ID
+	bool "SoC bus device for the ARM SMCCC SOC_ID"
+	depends on HAVE_ARM_SMCCC_DISCOVERY
+	default y
+	select SOC_BUS
+	help
+	  Include support for the SoC bus on the ARM SMCCC firmware based
+	  platforms providing some sysfs information about the SoC variant.
diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile
new file mode 100644
index 0000000000..40d19144a8
--- /dev/null
+++ b/drivers/firmware/smccc/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o kvm_guest.o
+obj-$(CONFIG_ARM_SMCCC_SOC_ID)	+= soc_id.o
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c
new file mode 100644
index 0000000000..89a68e7eea
--- /dev/null
+++ b/drivers/firmware/smccc/kvm_guest.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "smccc: KVM: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitmap.h>
+#include <linux/cache.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/hypervisor.h>
+
+static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
+
+void __init kvm_init_hyp_services(void)
+{
+	struct arm_smccc_res res;
+	u32 val[4];
+
+	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
+		return;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
+	if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
+	    res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
+	    res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
+	    res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
+		return;
+
+	memset(&res, 0, sizeof(res));
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
+
+	val[0] = lower_32_bits(res.a0);
+	val[1] = lower_32_bits(res.a1);
+	val[2] = lower_32_bits(res.a2);
+	val[3] = lower_32_bits(res.a3);
+
+	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
+
+	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
+		 res.a3, res.a2, res.a1, res.a0);
+}
+
+bool kvm_arm_hyp_service_available(u32 func_id)
+{
+	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
+		return false;
+
+	return test_bit(func_id, __kvm_arm_hyp_services);
+}
+EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
new file mode 100644
index 0000000000..db818f9dcb
--- /dev/null
+++ b/drivers/firmware/smccc/smccc.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "smccc: " fmt
+
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/arm-smccc.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <asm/archrandom.h>
+
+static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
+static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
+
+bool __ro_after_init smccc_trng_available = false;
+u64 __ro_after_init smccc_has_sve_hint = false;
+s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
+s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
+
+void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
+{
+	struct arm_smccc_res res;
+
+	smccc_version = version;
+	smccc_conduit = conduit;
+
+	smccc_trng_available = smccc_probe_trng();
+	if (IS_ENABLED(CONFIG_ARM64_SVE) &&
+	    smccc_version >= ARM_SMCCC_VERSION_1_3)
+		smccc_has_sve_hint = true;
+
+	if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
+	    (smccc_conduit != SMCCC_CONDUIT_NONE)) {
+		arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+				     ARM_SMCCC_ARCH_SOC_ID, &res);
+		if ((s32)res.a0 >= 0) {
+			arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
+			smccc_soc_id_version = (s32)res.a0;
+			arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
+			smccc_soc_id_revision = (s32)res.a0;
+		}
+	}
+}
+
+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;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
+
+u32 arm_smccc_get_version(void)
+{
+	return smccc_version;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_get_version);
+
+s32 arm_smccc_get_soc_id_version(void)
+{
+	return smccc_soc_id_version;
+}
+
+s32 arm_smccc_get_soc_id_revision(void)
+{
+	return smccc_soc_id_revision;
+}
+
+static int __init smccc_devices_init(void)
+{
+	struct platform_device *pdev;
+
+	if (smccc_trng_available) {
+		pdev = platform_device_register_simple("smccc_trng", -1,
+						       NULL, 0);
+		if (IS_ERR(pdev))
+			pr_err("smccc_trng: could not register device: %ld\n",
+			       PTR_ERR(pdev));
+	}
+
+	return 0;
+}
+device_initcall(smccc_devices_init);
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
new file mode 100644
index 0000000000..1990263fbb
--- /dev/null
+++ b/drivers/firmware/smccc/soc_id.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK	GENMASK(30, 24)
+/*
+ * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C)
+ * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification
+ * code with parity bit for the SiP. We can drop the parity bit.
+ */
+#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK	GENMASK(22, 16)
+#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK	GENMASK(15, 0)
+
+#define JEP106_BANK_CONT_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)))
+#define JEP106_ID_CODE(x)	\
+	(u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
+#define IMP_DEF_SOC_ID(x)	\
+	(u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
+
+static struct soc_device *soc_dev;
+static struct soc_device_attribute *soc_dev_attr;
+
+static int __init smccc_soc_init(void)
+{
+	int soc_id_rev, soc_id_version;
+	static char soc_id_str[20], soc_id_rev_str[12];
+	static char soc_id_jep106_id_str[12];
+
+	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+		return 0;
+
+	soc_id_version = arm_smccc_get_soc_id_version();
+	if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
+		pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
+		return 0;
+	}
+
+	if (soc_id_version < 0) {
+		pr_err("Invalid SoC Version: %x\n", soc_id_version);
+		return -EINVAL;
+	}
+
+	soc_id_rev = arm_smccc_get_soc_id_revision();
+	if (soc_id_rev < 0) {
+		pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
+		return -EINVAL;
+	}
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
+	sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
+		JEP106_BANK_CONT_CODE(soc_id_version),
+		JEP106_ID_CODE(soc_id_version));
+	sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
+		IMP_DEF_SOC_ID(soc_id_version));
+
+	soc_dev_attr->soc_id = soc_id_str;
+	soc_dev_attr->revision = soc_id_rev_str;
+	soc_dev_attr->family = soc_id_jep106_id_str;
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return PTR_ERR(soc_dev);
+	}
+
+	pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
+		soc_dev_attr->revision);
+
+	return 0;
+}
+module_init(smccc_soc_init);
+
+static void __exit smccc_soc_exit(void)
+{
+	if (soc_dev)
+		soc_device_unregister(soc_dev);
+	kfree(soc_dev_attr);
+}
+module_exit(smccc_soc_exit);