drivers: introduce Secure Monitor uclass
At the moment, we don't have a common API for working with
SM, only the smc_call() function. This approach is not generic
and difficult to configure and maintain.
This patch adds UCLASS_SM with the generic API:
- sm_call()
- sm_call_write()
- sm_call_read()
These functions operate with struct pt_regs, which describes
Secure Monitor arguments.
Signed-off-by: Alexey Romanov <avromanov@salutedevices.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20230921081346.22157-2-avromanov@salutedevices.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 0432c95..d2c5288 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -89,6 +89,7 @@
UCLASS_MDIO, /* MDIO bus */
UCLASS_MDIO_MUX, /* MDIO MUX/switch */
UCLASS_MEMORY, /* Memory Controller device */
+ UCLASS_SM, /* Secure Monitor driver */
UCLASS_MISC, /* Miscellaneous device */
UCLASS_MMC, /* SD / MMC card or chip */
UCLASS_MOD_EXP, /* RSA Mod Exp device */
diff --git a/include/sm-uclass.h b/include/sm-uclass.h
new file mode 100644
index 0000000..c114484
--- /dev/null
+++ b/include/sm-uclass.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2023 SberDevices, Inc.
+ *
+ * Author: Alexey Romanov <avromanov@salutedevices.com>
+ */
+
+#ifndef __SM_UCLASS_H__
+#define __SM_UCLASS_H__
+
+#include <asm/types.h>
+#include <asm/ptrace.h>
+
+struct udevice;
+
+/**
+ * struct sm_ops - The functions that a SM driver must implement.
+ *
+ * @sm_call: Request a secure monitor call with specified command.
+ *
+ * @sm_call_read: Request a secure monitor call and retrieve data
+ * from secure-monitor (depends on specified command).
+ *
+ * @sm_call_write: Request a secure monitor call and send data
+ * to secure-monitor (depends on specified command).
+ *
+ * The individual methods are described more fully below.
+ */
+struct sm_ops {
+ /**
+ * sm_call - generic SMC call to the secure-monitor
+ *
+ * @dev: Pointer to UCLASS_SM device
+ * @cmd_index: Index of the SMC function ID
+ * @smc_ret: Returned value from secure world
+ * @args: SMC arguments
+ *
+ * @return: 0 on success, a negative value on error
+ */
+ int (*sm_call)(struct udevice *dev, u32 cmd, s32 *smc_ret,
+ struct pt_regs *args);
+
+ /**
+ * sm_call_write - send data to secure-monitor
+ *
+ * @dev: Pointer to UCLASS_SM device
+ * @buffer: Buffer containing data to send
+ * @size: Size of the buffer
+ * @cmd: Index of the SMC function ID
+ * @args: SMC arguments
+ *
+ * @return: size of sent data on success, a negative value on error
+ */
+ int (*sm_call_write)(struct udevice *dev, void *buffer,
+ size_t size, u32 cmd, struct pt_regs *args);
+
+ /**
+ * sm_call_read - retrieve data from secure-monitor
+ *
+ * @dev: Pointer to UCLASS_SM device
+ * @buffer: Buffer to store the retrieved data
+ * @size: Size of the buffer
+ * @cmd: Index of the SMC function ID
+ * @args: SMC arguments
+ *
+ * @return: size of read data on success, a negative value on error
+ */
+ int (*sm_call_read)(struct udevice *dev, void *buffer,
+ size_t size, u32 cmd, struct pt_regs *args);
+};
+
+#endif /* __SM_UCLASS_H__ */
diff --git a/include/sm.h b/include/sm.h
new file mode 100644
index 0000000..afa9c89
--- /dev/null
+++ b/include/sm.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2023 SberDevices, Inc.
+ *
+ * Author: Alexey Romanov <avromanov@salutedevices.ru>
+ */
+
+#ifndef __SM_H__
+#define __SM_H__
+
+/*
+ * NOTE: UCLASS_SM is designed with the idea that
+ * each driver should convert @cmd to some raw
+ * value, which is known only for driver, and set this
+ * value to the first element of the @args->regs array.
+ * Therefore, it is necessary to pass the remaining
+ * arguments starting at index = 1. Anyway, driver
+ * implementation may vary, so, please, check the specific
+ * implementation of the driver you are using.
+ */
+
+#include <asm/types.h>
+#include <asm/ptrace.h>
+
+struct udevice;
+
+/**
+ * sm_call - generic SMC call to the secure-monitor
+ *
+ * @dev: Pointer to UCLASS_SM device
+ * @cmd_index: Index of the SMC function ID
+ * @smc_ret: Returned value from secure world
+ * @args: SMC arguments
+ *
+ * @return: 0 on success, a negative value on error
+ */
+int sm_call(struct udevice *dev, u32 cmd, s32 *ret, struct pt_regs *args);
+
+/**
+ * sm_call_read - retrieve data from secure-monitor
+ *
+ * @dev: Pointer to UCLASS_MESON_SM device
+ * @buffer: Buffer to store the retrieved data
+ * @size: Size of the buffer
+ * @cmd: Index of the SMC function ID
+ * @args: SMC arguments
+ *
+ * @return: size of read data on success, a negative value on error
+ */
+int sm_call_read(struct udevice *dev, void *buffer, size_t size,
+ u32 cmd, struct pt_regs *args);
+
+/**
+ * sm_call_write - send data to secure-monitor
+ *
+ * @dev: Pointer to UCLASS_SM device
+ * @buffer: Buffer containing data to send
+ * @size: Size of the buffer
+ * @cmd: Index of the SMC function ID
+ * @args: SMC arguments
+ *
+ * @return: size of sent data on success, a negative value on error
+ */
+int sm_call_write(struct udevice *dev, void *buffer, size_t size,
+ u32 cmd, struct pt_regs *args);
+
+#endif /* __SM_H__ */