Merge tag 'qcom-drivers-for-6.7' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into soc/drivers

Qualcomm driver updates for v6.7

This introduces partial support for the Qualcomm Secure Execution
Environment SCM interface, and uses this to implement EFI variable
access on the Windows On Snapdragon devices (for now).

The 32/64-bit calling convention detector of the SCM interface is
updated to not choose 64-bit convention when Linux is 32-bit. The
"extern" specifier is dropped from the interface include file.

The LLCC driver gains support for carrying configuration for multiple
different system/DDR configurations for a given platform, and selecting
between them. Support for Q[DR]U1000 is added to the driver.

All exported symbols are transitioned to EXPORT_SYMBOL_GPL().

The platform_drivers in the Qualcomm SoC are transitioned to the
void-returning remove_new implementation.

The rmtfs memory driver gains support for leaving guard pages around the
used area, to avoid issues if the allocation happens to be placed
adjacent to another protected memory region.

The socinfo driver gains knowledge about IPQ8174, QCM6490, SM7150P and
various PMICs used together with SM8550.

* tag 'qcom-drivers-for-6.7' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux: (44 commits)
  soc: qcom: socinfo: Convert to platform remove callback returning void
  soc: qcom: smsm: Convert to platform remove callback returning void
  soc: qcom: smp2p: Convert to platform remove callback returning void
  soc: qcom: smem: Convert to platform remove callback returning void
  soc: qcom: rmtfs_mem: Convert to platform remove callback returning void
  soc: qcom: qcom_stats: Convert to platform remove callback returning void
  soc: qcom: qcom_gsbi: Convert to platform remove callback returning void
  soc: qcom: qcom_aoss: Convert to platform remove callback returning void
  soc: qcom: pmic_glink: Convert to platform remove callback returning void
  soc: qcom: ocmem: Convert to platform remove callback returning void
  soc: qcom: llcc-qcom: Convert to platform remove callback returning void
  soc: qcom: icc-bwmon: Convert to platform remove callback returning void
  firmware: qcom_scm: use 64-bit calling convention only when client is 64-bit
  soc: qcom: llcc: Handle a second device without data corruption
  soc: qcom: Switch to EXPORT_SYMBOL_GPL()
  soc: qcom: smem: Annotate struct qcom_smem with __counted_by
  soc: qcom: rmtfs: Support discarding guard pages
  dt-bindings: reserved-memory: rmtfs: Allow guard pages
  dt-bindings: firmware: qcom,scm: document IPQ5018 compatible
  firmware: qcom_scm: disable SDI if required
  ...

Link: https://lore.kernel.org/r/20231015204014.855672-1-andersson@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

6 files changed, 1467 insertions, 8 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b59e3041fd62..8c608be30060 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -226,6 +226,39 @@ config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
 
 	  Say Y here to enable "download mode" by default.
 
+config QCOM_QSEECOM
+	bool "Qualcomm QSEECOM interface driver"
+	depends on QCOM_SCM=y
+	select AUXILIARY_BUS
+	help
+	  Various Qualcomm SoCs have a Secure Execution Environment (SEE) running
+	  in the Trust Zone. This module provides an interface to that via the
+	  QSEECOM mechanism, using SCM calls.
+
+	  The QSEECOM interface allows, among other things, access to applications
+	  running in the SEE. An example of such an application is 'uefisecapp',
+	  which is required to access UEFI variables on certain systems. If
+	  selected, the interface will also attempt to detect and register client
+	  devices for supported applications.
+
+	  Select Y here to enable the QSEECOM interface driver.
+
+config QCOM_QSEECOM_UEFISECAPP
+	bool "Qualcomm SEE UEFI Secure App client driver"
+	depends on QCOM_QSEECOM
+	depends on EFI
+	help
+	  Various Qualcomm SoCs do not allow direct access to EFI variables.
+	  Instead, these need to be accessed via the UEFI Secure Application
+	  (uefisecapp), residing in the Secure Execution Environment (SEE).
+
+	  This module provides a client driver for uefisecapp, installing efivar
+	  operations to allow the kernel accessing EFI variables, and via that also
+	  provide user-space with access to EFI variables via efivarfs.
+
+	  Select Y here to provide access to EFI variables on the aforementioned
+	  platforms.
+
 config SYSFB
 	bool
 	select BOOT_VESA_SUPPORT
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 28fcddcd688f..d41b094a5e58 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -20,6 +20,8 @@ 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_QCOM_QSEECOM)	+= qcom_qseecom.o
+obj-$(CONFIG_QCOM_QSEECOM_UEFISECAPP) += qcom_qseecom_uefisecapp.o
 obj-$(CONFIG_SYSFB)		+= sysfb.o
 obj-$(CONFIG_SYSFB_SIMPLEFB)	+= sysfb_simplefb.o
 obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
diff --git a/drivers/firmware/qcom_qseecom.c b/drivers/firmware/qcom_qseecom.c
new file mode 100644
index 000000000000..731e6d5719f9
--- /dev/null
+++ b/drivers/firmware/qcom_qseecom.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Qualcomm Secure Execution Environment (SEE) interface (QSEECOM).
+ * Responsible for setting up and managing QSEECOM client devices.
+ *
+ * Copyright (C) 2023 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+#include <linux/auxiliary_bus.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/firmware/qcom/qcom_qseecom.h>
+#include <linux/firmware/qcom/qcom_scm.h>
+
+struct qseecom_app_desc {
+	const char *app_name;
+	const char *dev_name;
+};
+
+static void qseecom_client_release(struct device *dev)
+{
+	struct qseecom_client *client;
+
+	client = container_of(dev, struct qseecom_client, aux_dev.dev);
+	kfree(client);
+}
+
+static void qseecom_client_remove(void *data)
+{
+	struct qseecom_client *client = data;
+
+	auxiliary_device_delete(&client->aux_dev);
+	auxiliary_device_uninit(&client->aux_dev);
+}
+
+static int qseecom_client_register(struct platform_device *qseecom_dev,
+				   const struct qseecom_app_desc *desc)
+{
+	struct qseecom_client *client;
+	u32 app_id;
+	int ret;
+
+	/* Try to find the app ID, skip device if not found */
+	ret = qcom_scm_qseecom_app_get_id(desc->app_name, &app_id);
+	if (ret)
+		return ret == -ENOENT ? 0 : ret;
+
+	dev_info(&qseecom_dev->dev, "setting up client for %s\n", desc->app_name);
+
+	/* Allocate and set-up the client device */
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	client->aux_dev.name = desc->dev_name;
+	client->aux_dev.dev.parent = &qseecom_dev->dev;
+	client->aux_dev.dev.release = qseecom_client_release;
+	client->app_id = app_id;
+
+	ret = auxiliary_device_init(&client->aux_dev);
+	if (ret) {
+		kfree(client);
+		return ret;
+	}
+
+	ret = auxiliary_device_add(&client->aux_dev);
+	if (ret) {
+		auxiliary_device_uninit(&client->aux_dev);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&qseecom_dev->dev, qseecom_client_remove, client);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * List of supported applications. One client device will be created per entry,
+ * assuming the app has already been loaded (usually by firmware bootloaders)
+ * and its ID can be queried successfully.
+ */
+static const struct qseecom_app_desc qcom_qseecom_apps[] = {
+	{ "qcom.tz.uefisecapp", "uefisecapp" },
+};
+
+static int qcom_qseecom_probe(struct platform_device *qseecom_dev)
+{
+	int ret;
+	int i;
+
+	/* Set up client devices for each base application */
+	for (i = 0; i < ARRAY_SIZE(qcom_qseecom_apps); i++) {
+		ret = qseecom_client_register(qseecom_dev, &qcom_qseecom_apps[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver qcom_qseecom_driver = {
+	.driver = {
+		.name	= "qcom_qseecom",
+	},
+	.probe = qcom_qseecom_probe,
+};
+
+static int __init qcom_qseecom_init(void)
+{
+	return platform_driver_register(&qcom_qseecom_driver);
+}
+subsys_initcall(qcom_qseecom_init);
+
+MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
+MODULE_DESCRIPTION("Driver for the Qualcomm SEE (QSEECOM) interface");
+MODULE_LICENSE("GPL");
diff --git a/drivers/firmware/qcom_qseecom_uefisecapp.c b/drivers/firmware/qcom_qseecom_uefisecapp.c
new file mode 100644
index 000000000000..a33acdaf7b78
--- /dev/null
+++ b/drivers/firmware/qcom_qseecom_uefisecapp.c
@@ -0,0 +1,871 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Client driver for Qualcomm UEFI Secure Application (qcom.tz.uefisecapp).
+ * Provides access to UEFI variables on platforms where they are secured by the
+ * aforementioned Secure Execution Environment (SEE) application.
+ *
+ * Copyright (C) 2023 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <linux/efi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/ucs2_string.h>
+
+#include <linux/firmware/qcom/qcom_qseecom.h>
+
+/* -- Qualcomm "uefisecapp" interface definitions. -------------------------- */
+
+/* Maximum length of name string with null-terminator */
+#define QSEE_MAX_NAME_LEN			1024
+
+#define QSEE_CMD_UEFI(x)			(0x8000 | (x))
+#define QSEE_CMD_UEFI_GET_VARIABLE		QSEE_CMD_UEFI(0)
+#define QSEE_CMD_UEFI_SET_VARIABLE		QSEE_CMD_UEFI(1)
+#define QSEE_CMD_UEFI_GET_NEXT_VARIABLE		QSEE_CMD_UEFI(2)
+#define QSEE_CMD_UEFI_QUERY_VARIABLE_INFO	QSEE_CMD_UEFI(3)
+
+/**
+ * struct qsee_req_uefi_get_variable - Request for GetVariable command.
+ * @command_id:  The ID of the command. Must be %QSEE_CMD_UEFI_GET_VARIABLE.
+ * @length:      Length of the request in bytes, including this struct and any
+ *               parameters (name, GUID) stored after it as well as any padding
+ *               thereof for alignment.
+ * @name_offset: Offset from the start of this struct to where the variable
+ *               name is stored (as utf-16 string), in bytes.
+ * @name_size:   Size of the name parameter in bytes, including null-terminator.
+ * @guid_offset: Offset from the start of this struct to where the GUID
+ *               parameter is stored, in bytes.
+ * @guid_size:   Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t).
+ * @data_size:   Size of the output buffer, in bytes.
+ */
+struct qsee_req_uefi_get_variable {
+	u32 command_id;
+	u32 length;
+	u32 name_offset;
+	u32 name_size;
+	u32 guid_offset;
+	u32 guid_size;
+	u32 data_size;
+} __packed;
+
+/**
+ * struct qsee_rsp_uefi_get_variable - Response for GetVariable command.
+ * @command_id:  The ID of the command. Should be %QSEE_CMD_UEFI_GET_VARIABLE.
+ * @length:      Length of the response in bytes, including this struct and the
+ *               returned data.
+ * @status:      Status of this command.
+ * @attributes:  EFI variable attributes.
+ * @data_offset: Offset from the start of this struct to where the data is
+ *               stored, in bytes.
+ * @data_size:   Size of the returned data, in bytes. In case status indicates
+ *               that the buffer is too small, this will be the size required
+ *               to store the EFI variable data.
+ */
+struct qsee_rsp_uefi_get_variable {
+	u32 command_id;
+	u32 length;
+	u32 status;
+	u32 attributes;
+	u32 data_offset;
+	u32 data_size;
+} __packed;
+
+/**
+ * struct qsee_req_uefi_set_variable - Request for the SetVariable command.
+ * @command_id:  The ID of the command. Must be %QSEE_CMD_UEFI_SET_VARIABLE.
+ * @length:      Length of the request in bytes, including this struct and any
+ *               parameters (name, GUID, data) stored after it as well as any
+ *               padding thereof required for alignment.
+ * @name_offset: Offset from the start of this struct to where the variable
+ *               name is stored (as utf-16 string), in bytes.
+ * @name_size:   Size of the name parameter in bytes, including null-terminator.
+ * @guid_offset: Offset from the start of this struct to where the GUID
+ *               parameter is stored, in bytes.
+ * @guid_size:   Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t).
+ * @attributes:  The EFI variable attributes to set for this variable.
+ * @data_offset: Offset from the start of this struct to where the EFI variable
+ *               data is stored, in bytes.
+ * @data_size:   Size of EFI variable data, in bytes.
+ *
+ */
+struct qsee_req_uefi_set_variable {
+	u32 command_id;
+	u32 length;
+	u32 name_offset;
+	u32 name_size;
+	u32 guid_offset;
+	u32 guid_size;
+	u32 attributes;
+	u32 data_offset;
+	u32 data_size;
+} __packed;
+
+/**
+ * struct qsee_rsp_uefi_set_variable - Response for the SetVariable command.
+ * @command_id:  The ID of the command. Should be %QSEE_CMD_UEFI_SET_VARIABLE.
+ * @length:      The length of this response, i.e. the size of this struct in
+ *               bytes.
+ * @status:      Status of this command.
+ * @_unknown1:   Unknown response field.
+ * @_unknown2:   Unknown response field.
+ */
+struct qsee_rsp_uefi_set_variable {
+	u32 command_id;
+	u32 length;
+	u32 status;
+	u32 _unknown1;
+	u32 _unknown2;
+} __packed;
+
+/**
+ * struct qsee_req_uefi_get_next_variable - Request for the
+ * GetNextVariableName command.
+ * @command_id:  The ID of the command. Must be
+ *               %QSEE_CMD_UEFI_GET_NEXT_VARIABLE.
+ * @length:      Length of the request in bytes, including this struct and any
+ *               parameters (name, GUID) stored after it as well as any padding
+ *               thereof for alignment.
+ * @guid_offset: Offset from the start of this struct to where the GUID
+ *               parameter is stored, in bytes.
+ * @guid_size:   Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t).
+ * @name_offset: Offset from the start of this struct to where the variable
+ *               name is stored (as utf-16 string), in bytes.
+ * @name_size:   Size of the name parameter in bytes, including null-terminator.
+ */
+struct qsee_req_uefi_get_next_variable {
+	u32 command_id;
+	u32 length;
+	u32 guid_offset;
+	u32 guid_size;
+	u32 name_offset;
+	u32 name_size;
+} __packed;
+
+/**
+ * struct qsee_rsp_uefi_get_next_variable - Response for the
+ * GetNextVariableName command.
+ * @command_id:  The ID of the command. Should be
+ *               %QSEE_CMD_UEFI_GET_NEXT_VARIABLE.
+ * @length:      Length of the response in bytes, including this struct and any
+ *               parameters (name, GUID) stored after it as well as any padding
+ *               thereof for alignment.
+ * @status:      Status of this command.
+ * @guid_offset: Offset from the start of this struct to where the GUID
+ *               parameter is stored, in bytes.
+ * @guid_size:   Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t).
+ * @name_offset: Offset from the start of this struct to where the variable
+ *               name is stored (as utf-16 string), in bytes.
+ * @name_size:   Size of the name parameter in bytes, including null-terminator.
+ */
+struct qsee_rsp_uefi_get_next_variable {
+	u32 command_id;
+	u32 length;
+	u32 status;
+	u32 guid_offset;
+	u32 guid_size;
+	u32 name_offset;
+	u32 name_size;
+} __packed;
+
+/**
+ * struct qsee_req_uefi_query_variable_info - Response for the
+ * GetNextVariableName command.
+ * @command_id: The ID of the command. Must be
+ *              %QSEE_CMD_UEFI_QUERY_VARIABLE_INFO.
+ * @length:     The length of this request, i.e. the size of this struct in
+ *              bytes.
+ * @attributes: The storage attributes to query the info for.
+ */
+struct qsee_req_uefi_query_variable_info {
+	u32 command_id;
+	u32 length;
+	u32 attributes;
+} __packed;
+
+/**
+ * struct qsee_rsp_uefi_query_variable_info - Response for the
+ * GetNextVariableName command.
+ * @command_id:        The ID of the command. Must be
+ *                     %QSEE_CMD_UEFI_QUERY_VARIABLE_INFO.
+ * @length:            The length of this response, i.e. the size of this
+ *                     struct in bytes.
+ * @status:            Status of this command.
+ * @_pad:              Padding.
+ * @storage_space:     Full storage space size, in bytes.
+ * @remaining_space:   Free storage space available, in bytes.
+ * @max_variable_size: Maximum variable data size, in bytes.
+ */
+struct qsee_rsp_uefi_query_variable_info {
+	u32 command_id;
+	u32 length;
+	u32 status;
+	u32 _pad;
+	u64 storage_space;
+	u64 remaining_space;
+	u64 max_variable_size;
+} __packed;
+
+/* -- Alignment helpers ----------------------------------------------------- */
+
+/*
+ * Helper macro to ensure proper alignment of types (fields and arrays) when
+ * stored in some (contiguous) buffer.
+ *
+ * Note: The driver from which this one has been reverse-engineered expects an
+ * alignment of 8 bytes (64 bits) for GUIDs. Our definition of efi_guid_t,
+ * however, has an alignment of 4 byte (32 bits). So far, this seems to work
+ * fine here. See also the comment on the typedef of efi_guid_t.
+ */
+#define qcuefi_buf_align_fields(fields...)					\
+	({									\
+		size_t __len = 0;						\
+		fields								\
+		__len;								\
+	})
+
+#define __field_impl(size, align, offset)					\
+	({									\
+		size_t *__offset = (offset);					\
+		size_t __aligned;						\
+										\
+		__aligned = ALIGN(__len, align);				\
+		__len = __aligned + (size);					\
+										\
+		if (__offset)							\
+			*__offset = __aligned;					\
+	});
+
+#define __array_offs(type, count, offset)					\
+	__field_impl(sizeof(type) * (count), __alignof__(type), offset)
+
+#define __array(type, count)		__array_offs(type, count, NULL)
+#define __field_offs(type, offset)	__array_offs(type, 1, offset)
+#define __field(type)			__array_offs(type, 1, NULL)
+
+/* -- UEFI app interface. --------------------------------------------------- */
+
+struct qcuefi_client {
+	struct qseecom_client *client;
+	struct efivars efivars;
+};
+
+static struct device *qcuefi_dev(struct qcuefi_client *qcuefi)
+{
+	return &qcuefi->client->aux_dev.dev;
+}
+
+static efi_status_t qsee_uefi_status_to_efi(u32 status)
+{
+	u64 category = status & 0xf0000000;
+	u64 code = status & 0x0fffffff;
+
+	return category << (BITS_PER_LONG - 32) | code;
+}
+
+static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const efi_char16_t *name,
+					   const efi_guid_t *guid, u32 *attributes,
+					   unsigned long *data_size, void *data)
+{
+	struct qsee_req_uefi_get_variable *req_data;
+	struct qsee_rsp_uefi_get_variable *rsp_data;
+	unsigned long buffer_size = *data_size;
+	efi_status_t efi_status = EFI_SUCCESS;
+	unsigned long name_length;
+	size_t guid_offs;
+	size_t name_offs;
+	size_t req_size;
+	size_t rsp_size;
+	ssize_t status;
+
+	if (!name || !guid)
+		return EFI_INVALID_PARAMETER;
+
+	name_length = ucs2_strnlen(name, QSEE_MAX_NAME_LEN) + 1;
+	if (name_length > QSEE_MAX_NAME_LEN)
+		return EFI_INVALID_PARAMETER;
+
+	if (buffer_size && !data)
+		return EFI_INVALID_PARAMETER;
+
+	req_size = qcuefi_buf_align_fields(
+		__field(*req_data)
+		__array_offs(*name, name_length, &name_offs)
+		__field_offs(*guid, &guid_offs)
+	);
+
+	rsp_size = qcuefi_buf_align_fields(
+		__field(*rsp_data)
+		__array(u8, buffer_size)
+	);
+
+	req_data = kzalloc(req_size, GFP_KERNEL);
+	if (!req_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	rsp_data = kzalloc(rsp_size, GFP_KERNEL);
+	if (!rsp_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out_free_req;
+	}
+
+	req_data->command_id = QSEE_CMD_UEFI_GET_VARIABLE;
+	req_data->data_size = buffer_size;
+	req_data->name_offset = name_offs;
+	req_data->name_size = name_length * sizeof(*name);
+	req_data->guid_offset = guid_offs;
+	req_data->guid_size = sizeof(*guid);
+	req_data->length = req_size;
+
+	status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name, name_length);
+	if (status < 0)
+		return EFI_INVALID_PARAMETER;
+
+	memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size);
+
+	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size);
+	if (status) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->command_id != QSEE_CMD_UEFI_GET_VARIABLE) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->length < sizeof(*rsp_data)) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->status) {
+		dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n",
+			__func__, rsp_data->status);
+		efi_status = qsee_uefi_status_to_efi(rsp_data->status);
+
+		/* Update size and attributes in case buffer is too small. */
+		if (efi_status == EFI_BUFFER_TOO_SMALL) {
+			*data_size = rsp_data->data_size;
+			if (attributes)
+				*attributes = rsp_data->attributes;
+		}
+
+		goto out_free;
+	}
+
+	if (rsp_data->length > rsp_size) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->data_offset + rsp_data->data_size > rsp_data->length) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	/*
+	 * Note: We need to set attributes and data size even if the buffer is
+	 * too small and we won't copy any data. This is described in spec, so
+	 * that callers can either allocate a buffer properly (with two calls
+	 * to this function) or just read back attributes withouth having to
+	 * deal with that.
+	 *
+	 * Specifically:
+	 * - If we have a buffer size of zero and no buffer, just return the
+	 *   attributes, required size, and indicate success.
+	 * - If the buffer size is nonzero but too small, indicate that as an
+	 *   error.
+	 * - Otherwise, we are good to copy the data.
+	 *
+	 * Note that we have already ensured above that the buffer pointer is
+	 * non-NULL if its size is nonzero.
+	 */
+	*data_size = rsp_data->data_size;
+	if (attributes)
+		*attributes = rsp_data->attributes;
+
+	if (buffer_size == 0 && !data) {
+		efi_status = EFI_SUCCESS;
+		goto out_free;
+	}
+
+	if (buffer_size < rsp_data->data_size) {
+		efi_status = EFI_BUFFER_TOO_SMALL;
+		goto out_free;
+	}
+
+	memcpy(data, ((void *)rsp_data) + rsp_data->data_offset, rsp_data->data_size);
+
+out_free:
+	kfree(rsp_data);
+out_free_req:
+	kfree(req_data);
+out:
+	return efi_status;
+}
+
+static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const efi_char16_t *name,
+					   const efi_guid_t *guid, u32 attributes,
+					   unsigned long data_size, const void *data)
+{
+	struct qsee_req_uefi_set_variable *req_data;
+	struct qsee_rsp_uefi_set_variable *rsp_data;
+	efi_status_t efi_status = EFI_SUCCESS;
+	unsigned long name_length;
+	size_t name_offs;
+	size_t guid_offs;
+	size_t data_offs;
+	size_t req_size;
+	ssize_t status;
+
+	if (!name || !guid)
+		return EFI_INVALID_PARAMETER;
+
+	name_length = ucs2_strnlen(name, QSEE_MAX_NAME_LEN) + 1;
+	if (name_length > QSEE_MAX_NAME_LEN)
+		return EFI_INVALID_PARAMETER;
+
+	/*
+	 * Make sure we have some data if data_size is nonzero. Note that using
+	 * a size of zero is a valid use-case described in spec and deletes the
+	 * variable.
+	 */
+	if (data_size && !data)
+		return EFI_INVALID_PARAMETER;
+
+	req_size = qcuefi_buf_align_fields(
+		__field(*req_data)
+		__array_offs(*name, name_length, &name_offs)
+		__field_offs(*guid, &guid_offs)
+		__array_offs(u8, data_size, &data_offs)
+	);
+
+	req_data = kzalloc(req_size, GFP_KERNEL);
+	if (!req_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL);
+	if (!rsp_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out_free_req;
+	}
+
+	req_data->command_id = QSEE_CMD_UEFI_SET_VARIABLE;
+	req_data->attributes = attributes;
+	req_data->name_offset = name_offs;
+	req_data->name_size = name_length * sizeof(*name);
+	req_data->guid_offset = guid_offs;
+	req_data->guid_size = sizeof(*guid);
+	req_data->data_offset = data_offs;
+	req_data->data_size = data_size;
+	req_data->length = req_size;
+
+	status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name, name_length);
+	if (status < 0)
+		return EFI_INVALID_PARAMETER;
+
+	memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size);
+
+	if (data_size)
+		memcpy(((void *)req_data) + req_data->data_offset, data, req_data->data_size);
+
+	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data,
+				       sizeof(*rsp_data));
+	if (status) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->command_id != QSEE_CMD_UEFI_SET_VARIABLE) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->length != sizeof(*rsp_data)) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->status) {
+		dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n",
+			__func__, rsp_data->status);
+		efi_status = qsee_uefi_status_to_efi(rsp_data->status);
+	}
+
+out_free:
+	kfree(rsp_data);
+out_free_req:
+	kfree(req_data);
+out:
+	return efi_status;
+}
+
+static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
+						unsigned long *name_size, efi_char16_t *name,
+						efi_guid_t *guid)
+{
+	struct qsee_req_uefi_get_next_variable *req_data;
+	struct qsee_rsp_uefi_get_next_variable *rsp_data;
+	efi_status_t efi_status = EFI_SUCCESS;
+	size_t guid_offs;
+	size_t name_offs;
+	size_t req_size;
+	size_t rsp_size;
+	ssize_t status;
+
+	if (!name_size || !name || !guid)
+		return EFI_INVALID_PARAMETER;
+
+	if (*name_size == 0)
+		return EFI_INVALID_PARAMETER;
+
+	req_size = qcuefi_buf_align_fields(
+		__field(*req_data)
+		__field_offs(*guid, &guid_offs)
+		__array_offs(*name, *name_size / sizeof(*name), &name_offs)
+	);
+
+	rsp_size = qcuefi_buf_align_fields(
+		__field(*rsp_data)
+		__field(*guid)
+		__array(*name, *name_size / sizeof(*name))
+	);
+
+	req_data = kzalloc(req_size, GFP_KERNEL);
+	if (!req_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	rsp_data = kzalloc(rsp_size, GFP_KERNEL);
+	if (!rsp_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out_free_req;
+	}
+
+	req_data->command_id = QSEE_CMD_UEFI_GET_NEXT_VARIABLE;
+	req_data->guid_offset = guid_offs;
+	req_data->guid_size = sizeof(*guid);
+	req_data->name_offset = name_offs;
+	req_data->name_size = *name_size;
+	req_data->length = req_size;
+
+	memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size);
+	status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name,
+			      *name_size / sizeof(*name));
+	if (status < 0)
+		return EFI_INVALID_PARAMETER;
+
+	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size);
+	if (status) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->command_id != QSEE_CMD_UEFI_GET_NEXT_VARIABLE) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->length < sizeof(*rsp_data)) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->status) {
+		dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n",
+			__func__, rsp_data->status);
+		efi_status = qsee_uefi_status_to_efi(rsp_data->status);
+
+		/*
+		 * If the buffer to hold the name is too small, update the
+		 * name_size with the required size, so that callers can
+		 * reallocate it accordingly.
+		 */
+		if (efi_status == EFI_BUFFER_TOO_SMALL)
+			*name_size = rsp_data->name_size;
+
+		goto out_free;
+	}
+
+	if (rsp_data->length > rsp_size) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->name_offset + rsp_data->name_size > rsp_data->length) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->guid_offset + rsp_data->guid_size > rsp_data->length) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->name_size > *name_size) {
+		*name_size = rsp_data->name_size;
+		efi_status = EFI_BUFFER_TOO_SMALL;
+		goto out_free;
+	}
+
+	if (rsp_data->guid_size != sizeof(*guid)) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	memcpy(guid, ((void *)rsp_data) + rsp_data->guid_offset, rsp_data->guid_size);
+	status = ucs2_strscpy(name, ((void *)rsp_data) + rsp_data->name_offset,
+			      rsp_data->name_size / sizeof(*name));
+	*name_size = rsp_data->name_size;
+
+	if (status < 0) {
+		/*
+		 * Return EFI_DEVICE_ERROR here because the buffer size should
+		 * have already been validated above, causing this function to
+		 * bail with EFI_BUFFER_TOO_SMALL.
+		 */
+		return EFI_DEVICE_ERROR;
+	}
+
+out_free:
+	kfree(rsp_data);
+out_free_req:
+	kfree(req_data);
+out:
+	return efi_status;
+}
+
+static efi_status_t qsee_uefi_query_variable_info(struct qcuefi_client *qcuefi, u32 attr,
+						  u64 *storage_space, u64 *remaining_space,
+						  u64 *max_variable_size)
+{
+	struct qsee_req_uefi_query_variable_info *req_data;
+	struct qsee_rsp_uefi_query_variable_info *rsp_data;
+	efi_status_t efi_status = EFI_SUCCESS;
+	int status;
+
+	req_data = kzalloc(sizeof(*req_data), GFP_KERNEL);
+	if (!req_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL);
+	if (!rsp_data) {
+		efi_status = EFI_OUT_OF_RESOURCES;
+		goto out_free_req;
+	}
+
+	req_data->command_id = QSEE_CMD_UEFI_QUERY_VARIABLE_INFO;
+	req_data->attributes = attr;
+	req_data->length = sizeof(*req_data);
+
+	status = qcom_qseecom_app_send(qcuefi->client, req_data, sizeof(*req_data), rsp_data,
+				       sizeof(*rsp_data));
+	if (status) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->command_id != QSEE_CMD_UEFI_QUERY_VARIABLE_INFO) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->length != sizeof(*rsp_data)) {
+		efi_status = EFI_DEVICE_ERROR;
+		goto out_free;
+	}
+
+	if (rsp_data->status) {
+		dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n",
+			__func__, rsp_data->status);
+		efi_status = qsee_uefi_status_to_efi(rsp_data->status);
+		goto out_free;
+	}
+
+	if (storage_space)
+		*storage_space = rsp_data->storage_space;
+
+	if (remaining_space)
+		*remaining_space = rsp_data->remaining_space;
+
+	if (max_variable_size)
+		*max_variable_size = rsp_data->max_variable_size;
+
+out_free:
+	kfree(rsp_data);
+out_free_req:
+	kfree(req_data);
+out:
+	return efi_status;
+}
+
+/* -- Global efivar interface. ---------------------------------------------- */
+
+static struct qcuefi_client *__qcuefi;
+static DEFINE_MUTEX(__qcuefi_lock);
+
+static int qcuefi_set_reference(struct qcuefi_client *qcuefi)
+{
+	mutex_lock(&__qcuefi_lock);
+
+	if (qcuefi && __qcuefi) {
+		mutex_unlock(&__qcuefi_lock);
+		return -EEXIST;
+	}
+
+	__qcuefi = qcuefi;
+
+	mutex_unlock(&__qcuefi_lock);
+	return 0;
+}
+
+static struct qcuefi_client *qcuefi_acquire(void)
+{
+	mutex_lock(&__qcuefi_lock);
+	return __qcuefi;
+}
+
+static void qcuefi_release(void)
+{
+	mutex_unlock(&__qcuefi_lock);
+}
+
+static efi_status_t qcuefi_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr,
+					unsigned long *data_size, void *data)
+{
+	struct qcuefi_client *qcuefi;
+	efi_status_t status;
+
+	qcuefi = qcuefi_acquire();
+	if (!qcuefi)
+		return EFI_NOT_READY;
+
+	status = qsee_uefi_get_variable(qcuefi, name, vendor, attr, data_size, data);
+
+	qcuefi_release();
+	return status;
+}
+
+static efi_status_t qcuefi_set_variable(efi_char16_t *name, efi_guid_t *vendor,
+					u32 attr, unsigned long data_size, void *data)
+{
+	struct qcuefi_client *qcuefi;
+	efi_status_t status;
+
+	qcuefi = qcuefi_acquire();
+	if (!qcuefi)
+		return EFI_NOT_READY;
+
+	status = qsee_uefi_set_variable(qcuefi, name, vendor, attr, data_size, data);
+
+	qcuefi_release();
+	return status;
+}
+
+static efi_status_t qcuefi_get_next_variable(unsigned long *name_size, efi_char16_t *name,
+					     efi_guid_t *vendor)
+{
+	struct qcuefi_client *qcuefi;
+	efi_status_t status;
+
+	qcuefi = qcuefi_acquire();
+	if (!qcuefi)
+		return EFI_NOT_READY;
+
+	status = qsee_uefi_get_next_variable(qcuefi, name_size, name, vendor);
+
+	qcuefi_release();
+	return status;
+}
+
+static efi_status_t qcuefi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space,
+					       u64 *max_variable_size)
+{
+	struct qcuefi_client *qcuefi;
+	efi_status_t status;
+
+	qcuefi = qcuefi_acquire();
+	if (!qcuefi)
+		return EFI_NOT_READY;
+
+	status = qsee_uefi_query_variable_info(qcuefi, attr, storage_space, remaining_space,
+					       max_variable_size);
+
+	qcuefi_release();
+	return status;
+}
+
+static const struct efivar_operations qcom_efivar_ops = {
+	.get_variable = qcuefi_get_variable,
+	.set_variable = qcuefi_set_variable,
+	.get_next_variable = qcuefi_get_next_variable,
+	.query_variable_info = qcuefi_query_variable_info,
+};
+
+/* -- Driver setup. --------------------------------------------------------- */
+
+static int qcom_uefisecapp_probe(struct auxiliary_device *aux_dev,
+				 const struct auxiliary_device_id *aux_dev_id)
+{
+	struct qcuefi_client *qcuefi;
+	int status;
+
+	qcuefi = devm_kzalloc(&aux_dev->dev, sizeof(*qcuefi), GFP_KERNEL);
+	if (!qcuefi)
+		return -ENOMEM;
+
+	qcuefi->client = container_of(aux_dev, struct qseecom_client, aux_dev);
+
+	auxiliary_set_drvdata(aux_dev, qcuefi);
+	status = qcuefi_set_reference(qcuefi);
+	if (status)
+		return status;
+
+	status = efivars_register(&qcuefi->efivars, &qcom_efivar_ops);
+	if (status)
+		qcuefi_set_reference(NULL);
+
+	return status;
+}
+
+static void qcom_uefisecapp_remove(struct auxiliary_device *aux_dev)
+{
+	struct qcuefi_client *qcuefi = auxiliary_get_drvdata(aux_dev);
+
+	efivars_unregister(&qcuefi->efivars);
+	qcuefi_set_reference(NULL);
+}
+
+static const struct auxiliary_device_id qcom_uefisecapp_id_table[] = {
+	{ .name = "qcom_qseecom.uefisecapp" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, qcom_uefisecapp_id_table);
+
+static struct auxiliary_driver qcom_uefisecapp_driver = {
+	.probe = qcom_uefisecapp_probe,
+	.remove = qcom_uefisecapp_remove,
+	.id_table = qcom_uefisecapp_id_table,
+	.driver = {
+		.name = "qcom_qseecom_uefisecapp",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_auxiliary_driver(qcom_uefisecapp_driver);
+
+MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
+MODULE_DESCRIPTION("Client driver for Qualcomm SEE UEFI Secure App");
+MODULE_LICENSE("GPL");
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 06fe8aca870d..520de9b5633a 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -2,24 +2,25 @@
 /* Copyright (c) 2010,2015,2019 The Linux Foundation. All rights reserved.
  * Copyright (C) 2015 Linaro Ltd.
  */
-#include <linux/platform_device.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
+
+#include <linux/arm-smccc.h>
+#include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/cpumask.h>
-#include <linux/export.h>
 #include <linux/dma-mapping.h>
+#include <linux/export.h>
+#include <linux/firmware/qcom/qcom_scm.h>
+#include <linux/init.h>
 #include <linux/interconnect.h>
+#include <linux/interrupt.h>
 #include <linux/module.h>
-#include <linux/types.h>
-#include <linux/firmware/qcom/qcom_scm.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
-#include <linux/clk.h>
+#include <linux/platform_device.h>
 #include <linux/reset-controller.h>
-#include <linux/arm-smccc.h>
+#include <linux/types.h>
 
 #include "qcom_scm.h"
 
@@ -55,6 +56,53 @@ struct qcom_scm_mem_map_info {
 	__le64 mem_size;
 };
 
+/**
+ * struct qcom_scm_qseecom_resp - QSEECOM SCM call response.
+ * @result:    Result or status of the SCM call. See &enum qcom_scm_qseecom_result.
+ * @resp_type: Type of the response. See &enum qcom_scm_qseecom_resp_type.
+ * @data:      Response data. The type of this data is given in @resp_type.
+ */
+struct qcom_scm_qseecom_resp {
+	u64 result;
+	u64 resp_type;
+	u64 data;
+};
+
+enum qcom_scm_qseecom_result {
+	QSEECOM_RESULT_SUCCESS			= 0,
+	QSEECOM_RESULT_INCOMPLETE		= 1,
+	QSEECOM_RESULT_BLOCKED_ON_LISTENER	= 2,
+	QSEECOM_RESULT_FAILURE			= 0xFFFFFFFF,
+};
+
+enum qcom_scm_qseecom_resp_type {
+	QSEECOM_SCM_RES_APP_ID			= 0xEE01,
+	QSEECOM_SCM_RES_QSEOS_LISTENER_ID	= 0xEE02,
+};
+
+enum qcom_scm_qseecom_tz_owner {
+	QSEECOM_TZ_OWNER_SIP			= 2,
+	QSEECOM_TZ_OWNER_TZ_APPS		= 48,
+	QSEECOM_TZ_OWNER_QSEE_OS		= 50
+};
+
+enum qcom_scm_qseecom_tz_svc {
+	QSEECOM_TZ_SVC_APP_ID_PLACEHOLDER	= 0,
+	QSEECOM_TZ_SVC_APP_MGR			= 1,
+	QSEECOM_TZ_SVC_INFO			= 6,
+};
+
+enum qcom_scm_qseecom_tz_cmd_app {
+	QSEECOM_TZ_CMD_APP_SEND			= 1,
+	QSEECOM_TZ_CMD_APP_LOOKUP		= 3,
+};
+
+enum qcom_scm_qseecom_tz_cmd_info {
+	QSEECOM_TZ_CMD_INFO_VERSION		= 3,
+};
+
+#define QSEECOM_MAX_APP_NAME_SIZE		64
+
 /* Each bit configures cold/warm boot address for one of the 4 CPUs */
 static const u8 qcom_scm_cpu_cold_bits[QCOM_SCM_BOOT_MAX_CPUS] = {
 	0, BIT(0), BIT(3), BIT(5)
@@ -168,6 +216,12 @@ static enum qcom_scm_convention __get_convention(void)
 		return qcom_scm_convention;
 
 	/*
+	 * Per the "SMC calling convention specification", the 64-bit calling
+	 * convention can only be used when the client is 64-bit, otherwise
+	 * system will encounter the undefined behaviour.
+	 */
+#if IS_ENABLED(CONFIG_ARM64)
+	/*
 	 * Device isn't required as there is only one argument - no device
 	 * needed to dma_map_single to secure world
 	 */
@@ -187,6 +241,7 @@ static enum qcom_scm_convention __get_convention(void)
 		forced = true;
 		goto found;
 	}
+#endif
 
 	probed_convention = SMC_CONVENTION_ARM_32;
 	ret = __scm_smc_call(NULL, &desc, probed_convention, &res, true);
@@ -403,6 +458,29 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
 }
 EXPORT_SYMBOL_GPL(qcom_scm_set_remote_state);
 
+static int qcom_scm_disable_sdi(void)
+{
+	int ret;
+	struct qcom_scm_desc desc = {
+		.svc = QCOM_SCM_SVC_BOOT,
+		.cmd = QCOM_SCM_BOOT_SDI_CONFIG,
+		.args[0] = 1, /* Disable watchdog debug */
+		.args[1] = 0, /* Disable SDI */
+		.arginfo = QCOM_SCM_ARGS(2),
+		.owner = ARM_SMCCC_OWNER_SIP,
+	};
+	struct qcom_scm_res res;
+
+	ret = qcom_scm_clk_enable();
+	if (ret)
+		return ret;
+	ret = qcom_scm_call(__scm->dev, &desc, &res);
+
+	qcom_scm_clk_disable();
+
+	return ret ? : res.result[0];
+}
+
 static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
 {
 	struct qcom_scm_desc desc = {
@@ -1321,6 +1399,340 @@ static int qcom_scm_find_dload_address(struct device *dev, u64 *addr)
 	return 0;
 }
 
+#ifdef CONFIG_QCOM_QSEECOM
+
+/* Lock for QSEECOM SCM call executions */
+static DEFINE_MUTEX(qcom_scm_qseecom_call_lock);
+
+static int __qcom_scm_qseecom_call(const struct qcom_scm_desc *desc,
+				   struct qcom_scm_qseecom_resp *res)
+{
+	struct qcom_scm_res scm_res = {};
+	int status;
+
+	/*
+	 * QSEECOM SCM calls should not be executed concurrently. Therefore, we
+	 * require the respective call lock to be held.
+	 */
+	lockdep_assert_held(&qcom_scm_qseecom_call_lock);
+
+	status = qcom_scm_call(__scm->dev, desc, &scm_res);
+
+	res->result = scm_res.result[0];
+	res->resp_type = scm_res.result[1];
+	res->data = scm_res.result[2];
+
+	if (status)
+		return status;
+
+	return 0;
+}
+
+/**
+ * qcom_scm_qseecom_call() - Perform a QSEECOM SCM call.
+ * @desc: SCM call descriptor.
+ * @res:  SCM call response (output).
+ *
+ * Performs the QSEECOM SCM call described by @desc, returning the response in
+ * @rsp.
+ *
+ * Return: Zero on success, nonzero on failure.
+ */
+static int qcom_scm_qseecom_call(const struct qcom_scm_desc *desc,
+				 struct qcom_scm_qseecom_resp *res)
+{
+	int status;
+
+	/*
+	 * Note: Multiple QSEECOM SCM calls should not be executed same time,
+	 * so lock things here. This needs to be extended to callback/listener
+	 * handling when support for that is implemented.
+	 */
+
+	mutex_lock(&qcom_scm_qseecom_call_lock);
+	status = __qcom_scm_qseecom_call(desc, res);
+	mutex_unlock(&qcom_scm_qseecom_call_lock);
+
+	dev_dbg(__scm->dev, "%s: owner=%x, svc=%x, cmd=%x, result=%lld, type=%llx, data=%llx\n",
+		__func__, desc->owner, desc->svc, desc->cmd, res->result,
+		res->resp_type, res->data);
+
+	if (status) {
+		dev_err(__scm->dev, "qseecom: scm call failed with error %d\n", status);
+		return status;
+	}
+
+	/*
+	 * TODO: Handle incomplete and blocked calls:
+	 *
+	 * Incomplete and blocked calls are not supported yet. Some devices
+	 * and/or commands require those, some don't. Let's warn about them
+	 * prominently in case someone attempts to try these commands with a
+	 * device/command combination that isn't supported yet.
+	 */
+	WARN_ON(res->result == QSEECOM_RESULT_INCOMPLETE);
+	WARN_ON(res->result == QSEECOM_RESULT_BLOCKED_ON_LISTENER);
+
+	return 0;
+}
+
+/**
+ * qcom_scm_qseecom_get_version() - Query the QSEECOM version.
+ * @version: Pointer where the QSEECOM version will be stored.
+ *
+ * Performs the QSEECOM SCM querying the QSEECOM version currently running in
+ * the TrustZone.
+ *
+ * Return: Zero on success, nonzero on failure.
+ */
+static int qcom_scm_qseecom_get_version(u32 *version)
+{
+	struct qcom_scm_desc desc = {};
+	struct qcom_scm_qseecom_resp res = {};
+	u32 feature = 10;
+	int ret;
+
+	desc.owner = QSEECOM_TZ_OWNER_SIP;
+	desc.svc = QSEECOM_TZ_SVC_INFO;
+	desc.cmd = QSEECOM_TZ_CMD_INFO_VERSION;
+	desc.arginfo = QCOM_SCM_ARGS(1, QCOM_SCM_VAL);
+	desc.args[0] = feature;
+
+	ret = qcom_scm_qseecom_call(&desc, &res);
+	if (ret)
+		return ret;
+
+	*version = res.result;
+	return 0;
+}
+
+/**
+ * qcom_scm_qseecom_app_get_id() - Query the app ID for a given QSEE app name.
+ * @app_name: The name of the app.
+ * @app_id:   The returned app ID.
+ *
+ * Query and return the application ID of the SEE app identified by the given
+ * name. This returned ID is the unique identifier of the app required for
+ * subsequent communication.
+ *
+ * Return: Zero on success, nonzero on failure, -ENOENT if the app has not been
+ * loaded or could not be found.
+ */
+int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id)
+{
+	unsigned long name_buf_size = QSEECOM_MAX_APP_NAME_SIZE;
+	unsigned long app_name_len = strlen(app_name);
+	struct qcom_scm_desc desc = {};
+	struct qcom_scm_qseecom_resp res = {};
+	dma_addr_t name_buf_phys;
+	char *name_buf;
+	int status;
+
+	if (app_name_len >= name_buf_size)
+		return -EINVAL;
+
+	name_buf = kzalloc(name_buf_size, GFP_KERNEL);
+	if (!name_buf)
+		return -ENOMEM;
+
+	memcpy(name_buf, app_name, app_name_len);
+
+	name_buf_phys = dma_map_single(__scm->dev, name_buf, name_buf_size, DMA_TO_DEVICE);
+	status = dma_mapping_error(__scm->dev, name_buf_phys);
+	if (status) {
+		kfree(name_buf);
+		dev_err(__scm->dev, "qseecom: failed to map dma address\n");
+		return status;
+	}
+
+	desc.owner = QSEECOM_TZ_OWNER_QSEE_OS;
+	desc.svc = QSEECOM_TZ_SVC_APP_MGR;
+	desc.cmd = QSEECOM_TZ_CMD_APP_LOOKUP;
+	desc.arginfo = QCOM_SCM_ARGS(2, QCOM_SCM_RW, QCOM_SCM_VAL);
+	desc.args[0] = name_buf_phys;
+	desc.args[1] = app_name_len;
+
+	status = qcom_scm_qseecom_call(&desc, &res);
+	dma_unmap_single(__scm->dev, name_buf_phys, name_buf_size, DMA_TO_DEVICE);
+	kfree(name_buf);
+
+	if (status)
+		return status;
+
+	if (res.result == QSEECOM_RESULT_FAILURE)
+		return -ENOENT;
+
+	if (res.result != QSEECOM_RESULT_SUCCESS)
+		return -EINVAL;
+
+	if (res.resp_type != QSEECOM_SCM_RES_APP_ID)
+		return -EINVAL;
+
+	*app_id = res.data;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_get_id);
+
+/**
+ * qcom_scm_qseecom_app_send() - Send to and receive data from a given QSEE app.
+ * @app_id:   The ID of the target app.
+ * @req:      Request buffer sent to the app (must be DMA-mappable).
+ * @req_size: Size of the request buffer.
+ * @rsp:      Response buffer, written to by the app (must be DMA-mappable).
+ * @rsp_size: Size of the response buffer.
+ *
+ * Sends a request to the QSEE app associated with the given ID and read back
+ * its response. The caller must provide two DMA memory regions, one for the
+ * request and one for the response, and fill out the @req region with the
+ * respective (app-specific) request data. The QSEE app reads this and returns
+ * its response in the @rsp region.
+ *
+ * Return: Zero on success, nonzero on failure.
+ */
+int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp,
+			      size_t rsp_size)
+{
+	struct qcom_scm_qseecom_resp res = {};
+	struct qcom_scm_desc desc = {};
+	dma_addr_t req_phys;
+	dma_addr_t rsp_phys;
+	int status;
+
+	/* Map request buffer */
+	req_phys = dma_map_single(__scm->dev, req, req_size, DMA_TO_DEVICE);
+	status = dma_mapping_error(__scm->dev, req_phys);
+	if (status) {
+		dev_err(__scm->dev, "qseecom: failed to map request buffer\n");
+		return status;
+	}
+
+	/* Map response buffer */
+	rsp_phys = dma_map_single(__scm->dev, rsp, rsp_size, DMA_FROM_DEVICE);
+	status = dma_mapping_error(__scm->dev, rsp_phys);
+	if (status) {
+		dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE);
+		dev_err(__scm->dev, "qseecom: failed to map response buffer\n");
+		return status;
+	}
+
+	/* Set up SCM call data */
+	desc.owner = QSEECOM_TZ_OWNER_TZ_APPS;
+	desc.svc = QSEECOM_TZ_SVC_APP_ID_PLACEHOLDER;
+	desc.cmd = QSEECOM_TZ_CMD_APP_SEND;
+	desc.arginfo = QCOM_SCM_ARGS(5, QCOM_SCM_VAL,
+				     QCOM_SCM_RW, QCOM_SCM_VAL,
+				     QCOM_SCM_RW, QCOM_SCM_VAL);
+	desc.args[0] = app_id;
+	desc.args[1] = req_phys;
+	desc.args[2] = req_size;
+	desc.args[3] = rsp_phys;
+	desc.args[4] = rsp_size;
+
+	/* Perform call */
+	status = qcom_scm_qseecom_call(&desc, &res);
+
+	/* Unmap buffers */
+	dma_unmap_single(__scm->dev, rsp_phys, rsp_size, DMA_FROM_DEVICE);
+	dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE);
+
+	if (status)
+		return status;
+
+	if (res.result != QSEECOM_RESULT_SUCCESS)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_send);
+
+/*
+ * We do not yet support re-entrant calls via the qseecom interface. To prevent
+ + any potential issues with this, only allow validated machines for now.
+ */
+static const struct of_device_id qcom_scm_qseecom_allowlist[] = {
+	{ .compatible = "lenovo,thinkpad-x13s", },
+	{ }
+};
+
+static bool qcom_scm_qseecom_machine_is_allowed(void)
+{
+	struct device_node *np;
+	bool match;
+
+	np = of_find_node_by_path("/");
+	if (!np)
+		return false;
+
+	match = of_match_node(qcom_scm_qseecom_allowlist, np);
+	of_node_put(np);
+
+	return match;
+}
+
+static void qcom_scm_qseecom_free(void *data)
+{
+	struct platform_device *qseecom_dev = data;
+
+	platform_device_del(qseecom_dev);
+	platform_device_put(qseecom_dev);
+}
+
+static int qcom_scm_qseecom_init(struct qcom_scm *scm)
+{
+	struct platform_device *qseecom_dev;
+	u32 version;
+	int ret;
+
+	/*
+	 * Note: We do two steps of validation here: First, we try to query the
+	 * QSEECOM version as a check to see if the interface exists on this
+	 * device. Second, we check against known good devices due to current
+	 * driver limitations (see comment in qcom_scm_qseecom_allowlist).
+	 *
+	 * Note that we deliberately do the machine check after the version
+	 * check so that we can log potentially supported devices. This should
+	 * be safe as downstream sources indicate that the version query is
+	 * neither blocking nor reentrant.
+	 */
+	ret = qcom_scm_qseecom_get_version(&version);
+	if (ret)
+		return 0;
+
+	dev_info(scm->dev, "qseecom: found qseecom with version 0x%x\n", version);
+
+	if (!qcom_scm_qseecom_machine_is_allowed()) {
+		dev_info(scm->dev, "qseecom: untested machine, skipping\n");
+		return 0;
+	}
+
+	/*
+	 * Set up QSEECOM interface device. All application clients will be
+	 * set up and managed by the corresponding driver for it.
+	 */
+	qseecom_dev = platform_device_alloc("qcom_qseecom", -1);
+	if (!qseecom_dev)
+		return -ENOMEM;
+
+	qseecom_dev->dev.parent = scm->dev;
+
+	ret = platform_device_add(qseecom_dev);
+	if (ret) {
+		platform_device_put(qseecom_dev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(scm->dev, qcom_scm_qseecom_free, qseecom_dev);
+}
+
+#else /* CONFIG_QCOM_QSEECOM */
+
+static int qcom_scm_qseecom_init(struct qcom_scm *scm)
+{
+	return 0;
+}
+
+#endif /* CONFIG_QCOM_QSEECOM */
+
 /**
  * qcom_scm_is_available() - Checks if SCM is available
  */
@@ -1468,6 +1880,26 @@ static int qcom_scm_probe(struct platform_device *pdev)
 	if (download_mode)
 		qcom_scm_set_download_mode(true);
 
+
+	/*
+	 * Disable SDI if indicated by DT that it is enabled by default.
+	 */
+	if (of_property_read_bool(pdev->dev.of_node, "qcom,sdi-enabled"))
+		qcom_scm_disable_sdi();
+
+	/*
+	 * Initialize the QSEECOM interface.
+	 *
+	 * Note: QSEECOM is fairly self-contained and this only adds the
+	 * interface device (the driver of which does most of the heavy
+	 * lifting). So any errors returned here should be either -ENOMEM or
+	 * -EINVAL (with the latter only in case there's a bug in our code).
+	 * This means that there is no need to bring down the whole SCM driver.
+	 * Just log the error instead and let SCM live.
+	 */
+	ret = qcom_scm_qseecom_init(scm);
+	WARN(ret < 0, "failed to initialize qseecom: %d\n", ret);
+
 	return 0;
 }
 
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index e6e512bd57d1..7b68fa820495 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -80,6 +80,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
 #define QCOM_SCM_SVC_BOOT		0x01
 #define QCOM_SCM_BOOT_SET_ADDR		0x01
 #define QCOM_SCM_BOOT_TERMINATE_PC	0x02
+#define QCOM_SCM_BOOT_SDI_CONFIG	0x09
 #define QCOM_SCM_BOOT_SET_DLOAD_MODE	0x10
 #define QCOM_SCM_BOOT_SET_ADDR_MC	0x11
 #define QCOM_SCM_BOOT_SET_REMOTE_STATE	0x0a