[PATCH 2/4] firmware: Samsung: Add secure monitor driver

* [PATCH 2/4] firmware: Samsung: Add secure monitor driver
       [not found] <CGME20220713045516epcms1p86b3f6a8795d767faac65eb947405f911@epcms1p8>
@ 2022-07-13  4:55 ` Dongjin Yang
  2022-07-13  4:58   ` Randy Dunlap
                     ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Dongjin Yang @ 2022-07-13  4:55 UTC (permalink / raw)
  To: jesper.nilsson, lars.persson, robh+dt, krzk+dt, lee.jones
  Cc: javierm, bjorn.andersson, linux-arm-kernel, devicetree,
	linux-kernel, Moon-Ki Jun, Sang Min Kim, Wangseok Lee,
	Dongjin Yang

Introduce a driver to provide calls into secure monitor mode.
This driver is used for SoCs produced by Samsung Foundry to provide
SMC call. This patch supports register read/write request to secure
monitor. Also, SMC call request which uses shared memory to exchange
the data between kernel and secure monitor.

Signed-off-by: Dongjin Yang <dj76.yang@samsung.com>
---
 MAINTAINERS                              |   2 +
 drivers/firmware/Kconfig                 |  11 +++
 drivers/firmware/Makefile                |   1 +
 drivers/firmware/samsung-smc-svc.c       | 154 +++++++++++++++++++++++++++++++
 include/linux/firmware/samsung-smc-svc.h |  59 ++++++++++++
 5 files changed, 227 insertions(+)
 create mode 100644 drivers/firmware/samsung-smc-svc.c
 create mode 100644 include/linux/firmware/samsung-smc-svc.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 6763746c349f..d173043ffb46 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1868,8 +1868,10 @@ F:	arch/arm/boot/dts/artpec6*
 F:	arch/arm/mach-artpec
 F:	drivers/clk/axis
 F:	drivers/crypto/axis
+F:	drivers/firmware/samsung-smc-svc.c
 F:	drivers/mmc/host/usdhi6rol0.c
 F:	drivers/pinctrl/pinctrl-artpec*
+F:	include/linux/firmware/samsung-smc-svc.h
 
 ARM/ASPEED I2C DRIVER
 M:	Brendan Higgins <brendanhiggins@google.com>
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index e5cfb01353d8..4b0f2d033f58 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -217,6 +217,17 @@ config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
 
 	  Say Y here to enable "download mode" by default.
 
+config SAMSUNG_SECURE_SERVICE
+	bool "Samsung Foundry Secure Service Layer"
+	depends on HAVE_ARM_SMCCC
+	default n
+	help
+	  Support secure service layer for SoCs which is manufactured by
+	  Samsung Foundry.
+
+	  This option provide support of secure monitor service call using
+	  Trusted Foundations.
+
 config SYSFB
 	bool
 	default y
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 4e58cb474a68..985e30a9665f 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
 obj-$(CONFIG_FW_CFG_SYSFS)	+= qemu_fw_cfg.o
 obj-$(CONFIG_QCOM_SCM)		+= qcom-scm.o
 qcom-scm-objs += qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o
+obj-$(CONFIG_SAMSUNG_SECURE_SERVICE) += samsung-smc-svc.o
 obj-$(CONFIG_SYSFB)		+= sysfb.o
 obj-$(CONFIG_SYSFB_SIMPLEFB)	+= sysfb_simplefb.o
 obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
diff --git a/drivers/firmware/samsung-smc-svc.c b/drivers/firmware/samsung-smc-svc.c
new file mode 100644
index 000000000000..eb3a5285cf2b
--- /dev/null
+++ b/drivers/firmware/samsung-smc-svc.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd.
+ * Author: Kihyun Yoon<kihyun.yoon@samsung.com>
+ * Author: Dongjin Yang<dj76.yang@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/firmware/samsung-smc-svc.h>
+
+struct samsung_smc_version {
+	u32 major;
+	u32 minor;
+};
+
+struct samsung_smc_data {
+	struct samsung_smc_version version;
+	u32 svc_cmd_list[SAMSUNG_SIP_NR_SIP];
+};
+
+struct samsung_smc_data *svc_data;
+
+static int samsung_smc_svc_init(void);
+
+static int __samsung_get_svc_cmd(u32 cmd_idx)
+{
+	if (cmd_idx >= SAMSUNG_SIP_NR_SIP)
+		return SAMSUNG_SIP_NOT_SUPPORTED;
+
+	/* Initialize this driver if it is not ready */
+	if (!svc_data && samsung_smc_svc_init()) {
+		pr_err("samsung,smccc_service initialization is failed\n");
+		return SAMSUNG_SIP_NOT_SUPPORTED;
+	}
+
+	return svc_data->svc_cmd_list[cmd_idx];
+}
+
+int samsung_smc_call(u32 cmd_idx,
+		     unsigned long a0, unsigned long a1,
+		     unsigned long a2, unsigned long a3,
+		     u32 *val)
+
+{
+	struct arm_smccc_res res;
+	u32 cmd = __samsung_get_svc_cmd(cmd_idx);
+
+	if (cmd == SAMSUNG_SIP_NOT_SUPPORTED)
+		return -EOPNOTSUPP;
+
+	arm_smccc_smc(cmd, a0, a1, a2, a3, 0, 0, 0, &res);
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		return -EINVAL;
+
+	if (val)
+		*val = (u32)res.a1;
+
+	return 0;
+}
+EXPORT_SYMBOL(samsung_smc_call);
+
+int samsung_smc_reg_read(void *base, u32 reg, u32 *val)
+{
+	return samsung_smc_call(SAMSUNG_SIP_READ_REG,
+				(unsigned long)base, reg, 0, 0, val);
+}
+EXPORT_SYMBOL(samsung_smc_reg_read);
+
+int samsung_smc_reg_write(void *base, u32 reg, u32 val)
+{
+	return samsung_smc_call(SAMSUNG_SIP_WRITE_REG,
+				  (unsigned long)base, reg, val, 0, NULL);
+}
+EXPORT_SYMBOL(samsung_smc_reg_write);
+
+static int samsung_smc_check_version(struct samsung_smc_version *ver)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SAMSUNG_SIP_SVC_VERSION, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if ((u32)res.a0 != ver->major || (u32)res.a1 != ver->minor)
+		return -EINVAL;
+
+	pr_info("Samsung SVC version [%d.%d] is detected\n",
+		ver->major, ver->minor);
+
+	return 0;
+}
+
+static const struct samsung_smc_data svc_0_1 = {
+	.version = {
+		.major = 0,
+		.minor = 1
+	},
+	.svc_cmd_list = {
+		[SAMSUNG_SIP_READ_REG] = 0x82000020,
+		[SAMSUNG_SIP_WRITE_REG] = 0x82000021,
+		/* TODO: SMC call for clock driver should be added */
+	}
+};
+
+static const struct of_device_id samsung_smc_of_match[] = {
+	{ .compatible = "samsung,smccc-svc", .data = &svc_0_1 },
+	{ /* sentinel */ }
+};
+
+static int samsung_smc_svc_init(void)
+{
+	struct device_node *fw_np;
+	struct device_node *np;
+	const struct of_device_id *match;
+	int ret;
+
+	if (svc_data) {
+		pr_info("samsung,smccc_service is already initialized\n");
+		return 0;
+	}
+
+	fw_np = of_find_node_by_name(NULL, "firmware");
+	if (!fw_np)
+		return -ENODEV;
+
+	np = of_find_matching_node_and_match(fw_np, samsung_smc_of_match,
+					     &match);
+	if (!np)
+		return -ENODEV;
+
+	svc_data = (struct samsung_smc_data *)match->data;
+	if (!svc_data)
+		return -ENODEV;
+
+	ret = samsung_smc_check_version(&svc_data->version);
+	if (ret) {
+		pr_err("samsung svc version is not matched\n");
+		return ret;
+	}
+
+	pr_info("samsung smc svc is initialized\n");
+	return 0;
+}
+
+early_initcall(samsung_smc_svc_init);
diff --git a/include/linux/firmware/samsung-smc-svc.h b/include/linux/firmware/samsung-smc-svc.h
new file mode 100644
index 000000000000..9c94fd3e10a2
--- /dev/null
+++ b/include/linux/firmware/samsung-smc-svc.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __SAMSUNG_SMC_H
+#define __SAMSUNG_SMC_H
+
+#include <linux/arm-smccc.h>
+
+#ifdef CONFIG_SAMSUNG_SECURE_SERVICE
+
+#define SAMSUNG_SIP_CALL_VAL(x) \
+		ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+		ARM_SMCCC_SMC_32, ARM_SMCCC_OWNER_SIP, x)
+
+/* Common SIP SVC number */
+#define SAMSUING_SIP_SVC_CALL_COUNT	SAMSUNG_SIP_CALL_VAL(0xff00)
+#define SAMSUING_SIP_SVC_UID		SAMSUNG_SIP_CALL_VAL(0xff01)
+#define SAMSUNG_SIP_SVC_VERSION		SAMSUNG_SIP_CALL_VAL(0xff03)
+#define SAMSUNG_SIP_NOT_SUPPORTED	0x0
+
+enum {
+	/* SIP enumeration for V0.1 */
+	SAMSUNG_SIP_READ_REG,
+	SAMSUNG_SIP_WRITE_REG,
+	/* Add here for later version */
+	SAMSUNG_SIP_NR_SIP
+};
+
+int samsung_smc_call(u32 cmd_idx,
+		     unsigned long a0, unsigned long a1,
+		     unsigned long a2, unsigned long a3,
+		     u32 *val);
+int samsung_smc_reg_read(void *addr, unsigned int reg, u32 *val);
+int samsung_smc_reg_write(void *addr, unsigned int reg, u32 val);
+
+#else
+
+static inline int samsung_smc_call(u32 cmd_idx,
+				   unsigned long a0, unsigned long a1,
+				   unsigned long a2, unsigned long a3,
+				   u32 *val)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int samsung_smc_reg_read(void *base,
+				       unsigned int reg, u32 *val)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int samsung_smc_reg_write(void *base,
+					unsigned int reg, u32 val)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif
+
+#endif /* __SAMSUNG_SMC_H */
-- 
2.9.5

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