[PATCH v1 1/2] drivers: firmware: introduce Meson Secure Monitor driver

Alexey Romanov avromanov at sberdevices.ru
Thu Jul 6 13:20:19 CEST 2023


At the moment, only smc API is a set of functions in
arch/arm/mach-meson/sm.c. This approach is hard to configure
and also doesn't contain any generic API for calling smc.

This patch add Meson SM driver with generic API (struct meson_sm_ops):

- sm_call()
- sm_call_write()
- sm_call_read()

A typical driver usage example is shown here:

1. uclass_get_device_by_driver(UCLASS_FIRMWARE, "secure-monitor", &dev);
2. handle = meson_sm_get_handle(dev);
3. handle->ops.sm_call(dev, cmd, ...);

Signed-off-by: Alexey Romanov <avromanov at sberdevices.ru>
---
 arch/arm/mach-meson/Kconfig       |   1 +
 drivers/firmware/Kconfig          |  10 ++
 drivers/firmware/Makefile         |   1 +
 drivers/firmware/meson/Kconfig    |   6 +
 drivers/firmware/meson/Makefile   |   3 +
 drivers/firmware/meson/meson_sm.c | 217 ++++++++++++++++++++++++++++++
 include/meson/sm_handle.h         |  38 ++++++
 7 files changed, 276 insertions(+)
 create mode 100644 drivers/firmware/meson/Kconfig
 create mode 100644 drivers/firmware/meson/Makefile
 create mode 100644 drivers/firmware/meson/meson_sm.c
 create mode 100644 include/meson/sm_handle.h

diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index 669ca09a00a..b8746d27f63 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -11,6 +11,7 @@ config MESON64_COMMON
 	select PWRSEQ
 	select MMC_PWRSEQ
 	select BOARD_LATE_INIT
+	select MESON_FIRMWARE
 	imply CMD_DM
 
 config MESON_GX
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index eae1c8ddc9f..17b70fdea6d 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -37,6 +37,15 @@ config ZYNQMP_FIRMWARE
 	  Say yes to enable ZynqMP firmware interface driver.
 	  If in doubt, say N.
 
+config MESON_FIRMWARE
+	bool "Meson Firmware interface"
+	select FIRMWARE
+	help
+	  This option enables Meson firmware interface,
+	  which is used by different drivers to communicate
+	  with the firmware for various platform management
+	  services.
+
 config ARM_SMCCC_FEATURES
 	bool "Arm SMCCC features discovery"
 	depends on ARM_PSCI_FW
@@ -45,4 +54,5 @@ config ARM_SMCCC_FEATURES
 	  the PSCI driver is always probed and binds dirvers registered to the Arm SMCCC
 	  services if any and reported as supported by the SMCCC firmware.
 
+source "drivers/firmware/meson/Kconfig"
 source "drivers/firmware/scmi/Kconfig"
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 7ce83d72bd3..a6300be27ad 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
 obj-$(CONFIG_SANDBOX)		+= firmware-sandbox.o
 obj-$(CONFIG_ZYNQMP_FIRMWARE)	+= firmware-zynqmp.o
 obj-$(CONFIG_SCMI_FIRMWARE)	+= scmi/
+obj-$(CONFIG_MESON_FIRMWARE)	+= meson/
diff --git a/drivers/firmware/meson/Kconfig b/drivers/firmware/meson/Kconfig
new file mode 100644
index 00000000000..0fd4f3251e1
--- /dev/null
+++ b/drivers/firmware/meson/Kconfig
@@ -0,0 +1,6 @@
+config MESON_SM
+	bool "Amlogic Secure Monitor driver"
+	depends on ARCH_MESON
+	default y
+	help
+	  Say y here to enable the Amlogic secure monitor driver.
diff --git a/drivers/firmware/meson/Makefile b/drivers/firmware/meson/Makefile
new file mode 100644
index 00000000000..b5d26f150b0
--- /dev/null
+++ b/drivers/firmware/meson/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_MESON_SM) +=	meson_sm.o
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
new file mode 100644
index 00000000000..28eacb89810
--- /dev/null
+++ b/drivers/firmware/meson/meson_sm.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2023 SberDevices, Inc.
+ *
+ * Author: Alexey Romanov <avromanov at sberdevices.ru>
+ */
+
+#include <dm.h>
+#include <common.h>
+#include <stdlib.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <linux/err.h>
+#include <linux/sizes.h>
+#include <linux/bitfield.h>
+#include <meson/sm_handle.h>
+
+struct meson_sm_cmd {
+	u32 smc_id;
+};
+
+#define SET_CMD(index, id)	\
+	[index] = {		\
+		.smc_id = id,	\
+	}
+
+struct meson_sm_data {
+	u32 cmd_get_shmem_in;
+	u32 cmd_get_shmem_out;
+	unsigned int shmem_size;
+	struct meson_sm_cmd cmd[];
+};
+
+struct meson_sm_priv {
+	void *sm_shmem_in;
+	void *sm_shmem_out;
+	struct meson_sm_handle handle;
+	const struct meson_sm_data *data;
+};
+
+static unsigned long __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,
+		u32 arg3, u32 arg4)
+{
+	struct pt_regs r;
+
+	r.regs[0] = cmd;
+	r.regs[1] = arg0;
+	r.regs[2] = arg1;
+	r.regs[3] = arg2;
+	r.regs[4] = arg3;
+	r.regs[5] = arg4;
+
+	smc_call(&r);
+
+	return r.regs[0];
+};
+
+static u32 meson_sm_get_cmd(const struct meson_sm_data *data,
+			    u32 cmd_index)
+{
+	struct meson_sm_cmd cmd;
+
+	if (cmd_index >= MESON_SMC_CMD_COUNT)
+		return 0;
+
+	cmd = data->cmd[cmd_index];
+	return cmd.smc_id;
+}
+
+static int meson_sm_call(struct udevice *dev, u32 cmd_index, u32 *retval,
+		u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	struct meson_sm_priv *priv = dev_get_priv(dev);
+	u32 cmd, ret;
+
+	cmd = meson_sm_get_cmd(priv->data, cmd_index);
+	if (!cmd)
+		return -ENOENT;
+
+	ret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
+	if (retval)
+		*retval = ret;
+
+	return 0;
+}
+
+static int meson_sm_call_read(struct udevice *dev, void *buffer, size_t size,
+		u32 cmd_index, u32 offset, u32 cnt)
+{
+	struct meson_sm_priv *priv = dev_get_priv(dev);
+	u32 nbytes;
+	int ret;
+
+	if (!buffer || size > priv->data->shmem_size)
+		return -EINVAL;
+
+	ret = meson_sm_call(dev, cmd_index, &nbytes, offset, cnt, 0, 0, 0);
+	if (ret)
+		return ret;
+
+	if (nbytes > size)
+		return -ENOBUFS;
+
+	/* In some cases (for example GET_CHIP_ID command),
+	 * SMC doesn't return the number of bytes read, even
+	 * though the bytes were actually read into sm_shmem_out.
+	 * So this check is needed.
+	 */
+	ret = nbytes;
+	if (!nbytes)
+		nbytes = size;
+
+	memcpy(buffer, priv->sm_shmem_out, nbytes);
+
+	return ret;
+}
+
+static int meson_sm_call_write(struct udevice *dev, void *buffer, size_t size,
+		u32 cmd_index, u32 offset, u32 cnt)
+{
+	struct meson_sm_priv *priv = dev_get_priv(dev);
+	u32 nbytes;
+	int ret;
+
+	if (!buffer || size > priv->data->shmem_size)
+		return -EINVAL;
+
+	memcpy(priv->sm_shmem_in, buffer, size);
+
+	ret = meson_sm_call(dev, cmd_index, &nbytes, offset, cnt, 0, 0, 0);
+	if (ret)
+		return ret;
+
+	if (!nbytes)
+		return -EIO;
+
+	return nbytes;
+}
+
+struct meson_sm_handle *meson_sm_get_handle(struct udevice *dev)
+{
+	struct meson_sm_priv *priv;
+	struct meson_sm_handle *handle;
+
+	priv = dev_get_priv(dev);
+	if (!priv)
+		return ERR_PTR(-EINVAL);
+
+	handle = &priv->handle;
+
+	return handle;
+}
+
+static const struct meson_sm_ops sm_ops = {
+	.sm_call = meson_sm_call,
+	.sm_call_read = meson_sm_call_read,
+	.sm_call_write = meson_sm_call_write,
+};
+
+static int meson_sm_probe(struct udevice *dev)
+{
+	struct meson_sm_priv *priv = dev_get_priv(dev);
+
+	priv->handle.ops = sm_ops;
+	priv->data = (struct meson_sm_data *)dev_get_driver_data(dev);
+	if (!priv->data)
+		return -EINVAL;
+
+	priv->sm_shmem_in =
+		(void *)__meson_sm_call(priv->data->cmd_get_shmem_in, 0, 0, 0, 0, 0);
+
+	if (!priv->sm_shmem_in)
+		return -ENOMEM;
+
+	priv->sm_shmem_out =
+		(void *)__meson_sm_call(priv->data->cmd_get_shmem_out, 0, 0, 0, 0, 0);
+
+	if (!priv->sm_shmem_out)
+		return -ENOMEM;
+
+	pr_debug("meson sm driver probed\n"
+		 "shmem_in addr: 0x%p, shmem_out addr: 0x%p\n",
+		 priv->sm_shmem_in,
+		 priv->sm_shmem_out);
+
+	return 0;
+}
+
+static const struct meson_sm_data meson_sm_gxbb_data = {
+	.cmd_get_shmem_in  = 0x82000020,
+	.cmd_get_shmem_out = 0x82000021,
+	.shmem_size = SZ_4K,
+	.cmd = {
+		SET_CMD(MESON_SMC_CMD_EFUSE_READ,  0x82000030),
+		SET_CMD(MESON_SMC_CMD_EFUSE_WRITE, 0x82000031),
+		SET_CMD(MESON_SMC_CMD_CHIP_ID_GET, 0x82000044),
+		SET_CMD(MESON_SMC_CMD_PWRDM_SET,   0x82000093),
+	},
+};
+
+static const struct udevice_id meson_sm_ids[] = {
+	{
+		.compatible = "amlogic,meson-gxbb-sm",
+		.data = (ulong)&meson_sm_gxbb_data,
+	},
+	{ }
+};
+
+U_BOOT_DRIVER(meson_sm) = {
+	.name = "meson_sm",
+	.id = UCLASS_FIRMWARE,
+	.of_match = meson_sm_ids,
+	.probe = meson_sm_probe,
+	.priv_auto = sizeof(struct meson_sm_priv),
+};
diff --git a/include/meson/sm_handle.h b/include/meson/sm_handle.h
new file mode 100644
index 00000000000..a3c69b77bd6
--- /dev/null
+++ b/include/meson/sm_handle.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2023 SberDevices, Inc.
+ *
+ * Author: Alexey Romanov <avromanov at sberdevices.ru>
+ */
+
+#ifndef _MESON_SM_H_
+#define _MESON_SM_H_
+
+#include <dm/device.h>
+
+enum meson_smc_cmd {
+	MESON_SMC_CMD_EFUSE_READ,
+	MESON_SMC_CMD_EFUSE_WRITE,
+	MESON_SMC_CMD_CHIP_ID_GET,
+	MESON_SMC_CMD_PWRDM_SET,
+	MESON_SMC_CMD_COUNT,
+};
+
+struct meson_sm_ops {
+	int (*sm_call)(struct udevice *dev, u32 cmd, u32 *ret,
+		u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
+
+	int (*sm_call_read)(struct udevice *dev, void *buffer,
+		size_t size, u32 cmd, u32 offset, u32 cnt);
+
+	int (*sm_call_write)(struct udevice *dev, void *buffer,
+		size_t size, u32 cmd, u32 offset, u32 cnt);
+};
+
+struct meson_sm_handle {
+	struct meson_sm_ops ops;
+};
+
+struct meson_sm_handle *meson_sm_get_handle(struct udevice *dev);
+
+#endif /* _MESON_SM_H_ */
-- 
2.38.1



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