drivers/nvmem/stm32-bsec-optee-ta.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * OP-TEE STM32MP BSEC PTA interface, used by STM32 ROMEM driver
  *
  * Copyright (C) 2022, STMicroelectronics - All Rights Reserved
  */

 #include <linux/tee_drv.h>

 #include "stm32-bsec-optee-ta.h"

 /*
  * Read OTP memory
  *
  * [in]		value[0].a		OTP start offset in byte
  * [in]		value[0].b		Access type (0:shadow, 1:fuse, 2:lock)
  * [out]	memref[1].buffer	Output buffer to store read values
  * [out]	memref[1].size		Size of OTP to be read
  *
  * Return codes:
  * TEE_SUCCESS - Invoke command success
  * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
  * TEE_ERROR_ACCESS_DENIED - OTP not accessible by caller
  */
 #define PTA_BSEC_READ_MEM		0x0

 /*
  * Write OTP memory
  *
  * [in]		value[0].a		OTP start offset in byte
  * [in]		value[0].b		Access type (0:shadow, 1:fuse, 2:lock)
  * [in]		memref[1].buffer	Input buffer to read values
  * [in]		memref[1].size		Size of OTP to be written
  *
  * Return codes:
  * TEE_SUCCESS - Invoke command success
  * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
  * TEE_ERROR_ACCESS_DENIED - OTP not accessible by caller
  */
 #define PTA_BSEC_WRITE_MEM		0x1

 /* value of PTA_BSEC access type = value[in] b */
 #define SHADOW_ACCESS	0
 #define FUSE_ACCESS	1
 #define LOCK_ACCESS	2

 /* Bitfield definition for LOCK status */
 #define LOCK_PERM			BIT(30)

 /* OP-TEE STM32MP BSEC TA UUID */
 static const uuid_t stm32mp_bsec_ta_uuid =
 	UUID_INIT(0x94cf71ad, 0x80e6, 0x40b5,
 		  0xa7, 0xc6, 0x3d, 0xc5, 0x01, 0xeb, 0x28, 0x03);

 /*
  * Check whether this driver supports the BSEC TA in the TEE instance
  * represented by the params (ver/data) to this function.
  */
 static int stm32_bsec_optee_ta_match(struct tee_ioctl_version_data *ver,
 				     const void *data)
 {
 	/* Currently this driver only supports GP compliant, OP-TEE based TA */
 	if ((ver->impl_id == TEE_IMPL_ID_OPTEE) &&
 		(ver->gen_caps & TEE_GEN_CAP_GP))
 		return 1;
 	else
 		return 0;
 }

 /* Open a session to OP-TEE for STM32MP BSEC TA */
 static int stm32_bsec_ta_open_session(struct tee_context *ctx, u32 *id)
 {
 	struct tee_ioctl_open_session_arg sess_arg;
 	int rc;

 	memset(&sess_arg, 0, sizeof(sess_arg));
 	export_uuid(sess_arg.uuid, &stm32mp_bsec_ta_uuid);
 	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
 	sess_arg.num_params = 0;

 	rc = tee_client_open_session(ctx, &sess_arg, NULL);
 	if ((rc < 0) || (sess_arg.ret != 0)) {
 		pr_err("%s: tee_client_open_session failed err:%#x, ret:%#x\n",
 		       __func__, sess_arg.ret, rc);
 		if (!rc)
 			rc = -EINVAL;
 	} else {
 		*id = sess_arg.session;
 	}

 	return rc;
 }

 /* close a session to OP-TEE for STM32MP BSEC TA */
 static void stm32_bsec_ta_close_session(void *ctx, u32 id)
 {
 	tee_client_close_session(ctx, id);
 }

 /* stm32_bsec_optee_ta_open() - initialize the STM32MP BSEC TA */
 int stm32_bsec_optee_ta_open(struct tee_context **ctx)
 {
 	struct tee_context *tee_ctx;
 	u32 session_id;
 	int rc;

 	/* Open context with TEE driver */
 	tee_ctx = tee_client_open_context(NULL, stm32_bsec_optee_ta_match, NULL, NULL);
 	if (IS_ERR(tee_ctx)) {
 		rc = PTR_ERR(tee_ctx);
 		if (rc == -ENOENT)
 			return -EPROBE_DEFER;
 		pr_err("%s: tee_client_open_context failed (%d)\n", __func__, rc);

 		return rc;
 	}

 	/* Check STM32MP BSEC TA presence */
 	rc = stm32_bsec_ta_open_session(tee_ctx, &session_id);
 	if (rc) {
 		tee_client_close_context(tee_ctx);
 		return rc;
 	}

 	stm32_bsec_ta_close_session(tee_ctx, session_id);

 	*ctx = tee_ctx;

 	return 0;
 }

 /* stm32_bsec_optee_ta_open() - release the PTA STM32MP BSEC TA */
 void stm32_bsec_optee_ta_close(void *ctx)
 {
 	tee_client_close_context(ctx);
 }

 /* stm32_bsec_optee_ta_read() - nvmem read access using PTA client driver */
 int stm32_bsec_optee_ta_read(struct tee_context *ctx, unsigned int offset,
 			     void *buf, size_t bytes)
 {
 	struct tee_shm *shm;
 	struct tee_ioctl_invoke_arg arg;
 	struct tee_param param[2];
 	u8 *shm_buf;
 	u32 start, num_bytes;
 	int ret;
 	u32 session_id;

 	ret = stm32_bsec_ta_open_session(ctx, &session_id);
 	if (ret)
 		return ret;

 	memset(&arg, 0, sizeof(arg));
 	memset(&param, 0, sizeof(param));

 	arg.func = PTA_BSEC_READ_MEM;
 	arg.session = session_id;
 	arg.num_params = 2;

 	/* align access on 32bits */
 	start = ALIGN_DOWN(offset, 4);
 	num_bytes = round_up(offset + bytes - start, 4);
 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
 	param[0].u.value.a = start;
 	param[0].u.value.b = SHADOW_ACCESS;

 	shm = tee_shm_alloc_kernel_buf(ctx, num_bytes);
 	if (IS_ERR(shm)) {
 		ret = PTR_ERR(shm);
 		goto out_tee_session;
 	}

 	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
 	param[1].u.memref.shm = shm;
 	param[1].u.memref.size = num_bytes;

 	ret = tee_client_invoke_func(ctx, &arg, param);
 	if (ret < 0 || arg.ret != 0) {
 		pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n",
 			arg.ret, ret);
 		if (!ret)
 			ret = -EIO;
 	}
 	if (!ret) {
 		shm_buf = tee_shm_get_va(shm, 0);
 		if (IS_ERR(shm_buf)) {
 			ret = PTR_ERR(shm_buf);
 			pr_err("tee_shm_get_va failed for transmit (%d)\n", ret);
 		} else {
 			/* read data from 32 bits aligned buffer */
 			memcpy(buf, &shm_buf[offset % 4], bytes);
 		}
 	}

 	tee_shm_free(shm);

 out_tee_session:
 	stm32_bsec_ta_close_session(ctx, session_id);

 	return ret;
 }

 /* stm32_bsec_optee_ta_write() - nvmem write access using PTA client driver */
 int stm32_bsec_optee_ta_write(struct tee_context *ctx, unsigned int lower,
 			      unsigned int offset, void *buf, size_t bytes)
 {	struct tee_shm *shm;
 	struct tee_ioctl_invoke_arg arg;
 	struct tee_param param[2];
 	u8 *shm_buf;
 	int ret;
 	u32 session_id;

 	ret = stm32_bsec_ta_open_session(ctx, &session_id);
 	if (ret)
 		return ret;

 	/* Allow only writing complete 32-bits aligned words */
 	if ((bytes % 4) || (offset % 4))
 		return -EINVAL;

 	memset(&arg, 0, sizeof(arg));
 	memset(&param, 0, sizeof(param));

 	arg.func = PTA_BSEC_WRITE_MEM;
 	arg.session = session_id;
 	arg.num_params = 2;

 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
 	param[0].u.value.a = offset;
 	param[0].u.value.b = FUSE_ACCESS;

 	shm = tee_shm_alloc_kernel_buf(ctx, bytes);
 	if (IS_ERR(shm)) {
 		ret = PTR_ERR(shm);
 		goto out_tee_session;
 	}

 	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
 	param[1].u.memref.shm = shm;
 	param[1].u.memref.size = bytes;

 	shm_buf = tee_shm_get_va(shm, 0);
 	if (IS_ERR(shm_buf)) {
 		ret = PTR_ERR(shm_buf);
 		pr_err("tee_shm_get_va failed for transmit (%d)\n", ret);
 		tee_shm_free(shm);

 		goto out_tee_session;
 	}

 	memcpy(shm_buf, buf, bytes);

 	ret = tee_client_invoke_func(ctx, &arg, param);
 	if (ret < 0 || arg.ret != 0) {
 		pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n", arg.ret, ret);
 		if (!ret)
 			ret = -EIO;
 	}
 	pr_debug("Write OTPs %d to %zu, ret=%d\n", offset / 4, (offset + bytes) / 4, ret);

 	/* Lock the upper OTPs with ECC protection, word programming only */
 	if (!ret && ((offset + bytes) >= (lower * 4))) {
 		u32 start, nb_lock;
 		u32 *lock = (u32 *)shm_buf;
 		int i;

 		/*
 		 * don't lock the lower OTPs, no ECC protection and incremental
 		 * bit programming, a second write is allowed
 		 */
 		start = max_t(u32, offset, lower * 4);
 		nb_lock = (offset + bytes - start) / 4;

 		param[0].u.value.a = start;
 		param[0].u.value.b = LOCK_ACCESS;
 		param[1].u.memref.size = nb_lock * 4;

 		for (i = 0; i < nb_lock; i++)
 			lock[i] = LOCK_PERM;

 		ret = tee_client_invoke_func(ctx, &arg, param);
 		if (ret < 0 || arg.ret != 0) {
 			pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n", arg.ret, ret);
 			if (!ret)
 				ret = -EIO;
 		}
 		pr_debug("Lock upper OTPs %d to %d, ret=%d\n",
 			 start / 4, start / 4 + nb_lock, ret);
 	}

 	tee_shm_free(shm);

 out_tee_session:
 	stm32_bsec_ta_close_session(ctx, session_id);

 	return ret;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* OP-TEE STM32MP BSEC PTA interface, used by STM32 ROMEM driver
	*
	* Copyright (C) 2022, STMicroelectronics - All Rights Reserved
	*/

	#include <linux/tee_drv.h>

	#include "stm32-bsec-optee-ta.h"

	/*
	* Read OTP memory
	*
	* [in] value[0].a OTP start offset in byte
	* [in] value[0].b Access type (0:shadow, 1:fuse, 2:lock)
	* [out] memref[1].buffer Output buffer to store read values
	* [out] memref[1].size Size of OTP to be read
	*
	* Return codes:
	* TEE_SUCCESS - Invoke command success
	* TEE_ERROR_BAD_PARAMETERS - Incorrect input param
	* TEE_ERROR_ACCESS_DENIED - OTP not accessible by caller
	*/
	#define PTA_BSEC_READ_MEM 0x0

	/*
	* Write OTP memory
	*
	* [in] value[0].a OTP start offset in byte
	* [in] value[0].b Access type (0:shadow, 1:fuse, 2:lock)
	* [in] memref[1].buffer Input buffer to read values
	* [in] memref[1].size Size of OTP to be written
	*
	* Return codes:
	* TEE_SUCCESS - Invoke command success
	* TEE_ERROR_BAD_PARAMETERS - Incorrect input param
	* TEE_ERROR_ACCESS_DENIED - OTP not accessible by caller
	*/
	#define PTA_BSEC_WRITE_MEM 0x1

	/* value of PTA_BSEC access type = value[in] b */
	#define SHADOW_ACCESS 0
	#define FUSE_ACCESS 1
	#define LOCK_ACCESS 2

	/* Bitfield definition for LOCK status */
	#define LOCK_PERM BIT(30)

	/* OP-TEE STM32MP BSEC TA UUID */
	static const uuid_t stm32mp_bsec_ta_uuid =
	UUID_INIT(0x94cf71ad, 0x80e6, 0x40b5,
	0xa7, 0xc6, 0x3d, 0xc5, 0x01, 0xeb, 0x28, 0x03);

	/*
	* Check whether this driver supports the BSEC TA in the TEE instance
	* represented by the params (ver/data) to this function.
	*/
	static int stm32_bsec_optee_ta_match(struct tee_ioctl_version_data *ver,
	const void *data)
	{
	/* Currently this driver only supports GP compliant, OP-TEE based TA */
	if ((ver->impl_id == TEE_IMPL_ID_OPTEE) &&
	(ver->gen_caps & TEE_GEN_CAP_GP))
	return 1;
	else
	return 0;
	}

	/* Open a session to OP-TEE for STM32MP BSEC TA */
	static int stm32_bsec_ta_open_session(struct tee_context ctx, u32 id)
	{
	struct tee_ioctl_open_session_arg sess_arg;
	int rc;

	memset(&sess_arg, 0, sizeof(sess_arg));
	export_uuid(sess_arg.uuid, &stm32mp_bsec_ta_uuid);
	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
	sess_arg.num_params = 0;

	rc = tee_client_open_session(ctx, &sess_arg, NULL);
	if ((rc < 0) \|\| (sess_arg.ret != 0)) {
	pr_err("%s: tee_client_open_session failed err:%#x, ret:%#x\n",
	__func__, sess_arg.ret, rc);
	if (!rc)
	rc = -EINVAL;
	} else {
	*id = sess_arg.session;
	}

	return rc;
	}

	/* close a session to OP-TEE for STM32MP BSEC TA */
	static void stm32_bsec_ta_close_session(void *ctx, u32 id)
	{
	tee_client_close_session(ctx, id);
	}

	/* stm32_bsec_optee_ta_open() - initialize the STM32MP BSEC TA */
	int stm32_bsec_optee_ta_open(struct tee_context **ctx)
	{
	struct tee_context *tee_ctx;
	u32 session_id;
	int rc;

	/* Open context with TEE driver */
	tee_ctx = tee_client_open_context(NULL, stm32_bsec_optee_ta_match, NULL, NULL);
	if (IS_ERR(tee_ctx)) {
	rc = PTR_ERR(tee_ctx);
	if (rc == -ENOENT)
	return -EPROBE_DEFER;
	pr_err("%s: tee_client_open_context failed (%d)\n", __func__, rc);

	return rc;
	}

	/* Check STM32MP BSEC TA presence */
	rc = stm32_bsec_ta_open_session(tee_ctx, &session_id);
	if (rc) {
	tee_client_close_context(tee_ctx);
	return rc;
	}

	stm32_bsec_ta_close_session(tee_ctx, session_id);

	*ctx = tee_ctx;

	return 0;
	}

	/* stm32_bsec_optee_ta_open() - release the PTA STM32MP BSEC TA */
	void stm32_bsec_optee_ta_close(void *ctx)
	{
	tee_client_close_context(ctx);
	}

	/* stm32_bsec_optee_ta_read() - nvmem read access using PTA client driver */
	int stm32_bsec_optee_ta_read(struct tee_context *ctx, unsigned int offset,
	void *buf, size_t bytes)
	{
	struct tee_shm *shm;
	struct tee_ioctl_invoke_arg arg;
	struct tee_param param[2];
	u8 *shm_buf;
	u32 start, num_bytes;
	int ret;
	u32 session_id;

	ret = stm32_bsec_ta_open_session(ctx, &session_id);
	if (ret)
	return ret;

	memset(&arg, 0, sizeof(arg));
	memset(&param, 0, sizeof(param));

	arg.func = PTA_BSEC_READ_MEM;
	arg.session = session_id;
	arg.num_params = 2;

	/* align access on 32bits */
	start = ALIGN_DOWN(offset, 4);
	num_bytes = round_up(offset + bytes - start, 4);
	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
	param[0].u.value.a = start;
	param[0].u.value.b = SHADOW_ACCESS;

	shm = tee_shm_alloc_kernel_buf(ctx, num_bytes);
	if (IS_ERR(shm)) {
	ret = PTR_ERR(shm);
	goto out_tee_session;
	}

	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
	param[1].u.memref.shm = shm;
	param[1].u.memref.size = num_bytes;

	ret = tee_client_invoke_func(ctx, &arg, param);
	if (ret < 0 \|\| arg.ret != 0) {
	pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n",
	arg.ret, ret);
	if (!ret)
	ret = -EIO;
	}
	if (!ret) {
	shm_buf = tee_shm_get_va(shm, 0);
	if (IS_ERR(shm_buf)) {
	ret = PTR_ERR(shm_buf);
	pr_err("tee_shm_get_va failed for transmit (%d)\n", ret);
	} else {
	/* read data from 32 bits aligned buffer */
	memcpy(buf, &shm_buf[offset % 4], bytes);
	}
	}

	tee_shm_free(shm);

	out_tee_session:
	stm32_bsec_ta_close_session(ctx, session_id);

	return ret;
	}

	/* stm32_bsec_optee_ta_write() - nvmem write access using PTA client driver */
	int stm32_bsec_optee_ta_write(struct tee_context *ctx, unsigned int lower,
	unsigned int offset, void *buf, size_t bytes)
	{ struct tee_shm *shm;
	struct tee_ioctl_invoke_arg arg;
	struct tee_param param[2];
	u8 *shm_buf;
	int ret;
	u32 session_id;

	ret = stm32_bsec_ta_open_session(ctx, &session_id);
	if (ret)
	return ret;

	/* Allow only writing complete 32-bits aligned words */
	if ((bytes % 4) \|\| (offset % 4))
	return -EINVAL;

	memset(&arg, 0, sizeof(arg));
	memset(&param, 0, sizeof(param));

	arg.func = PTA_BSEC_WRITE_MEM;
	arg.session = session_id;
	arg.num_params = 2;

	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
	param[0].u.value.a = offset;
	param[0].u.value.b = FUSE_ACCESS;

	shm = tee_shm_alloc_kernel_buf(ctx, bytes);
	if (IS_ERR(shm)) {
	ret = PTR_ERR(shm);
	goto out_tee_session;
	}

	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
	param[1].u.memref.shm = shm;
	param[1].u.memref.size = bytes;

	shm_buf = tee_shm_get_va(shm, 0);
	if (IS_ERR(shm_buf)) {
	ret = PTR_ERR(shm_buf);
	pr_err("tee_shm_get_va failed for transmit (%d)\n", ret);
	tee_shm_free(shm);

	goto out_tee_session;
	}

	memcpy(shm_buf, buf, bytes);

	ret = tee_client_invoke_func(ctx, &arg, param);
	if (ret < 0 \|\| arg.ret != 0) {
	pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n", arg.ret, ret);
	if (!ret)
	ret = -EIO;
	}
	pr_debug("Write OTPs %d to %zu, ret=%d\n", offset / 4, (offset + bytes) / 4, ret);

	/* Lock the upper OTPs with ECC protection, word programming only */
	if (!ret && ((offset + bytes) >= (lower * 4))) {
	u32 start, nb_lock;
	u32 lock = (u32 )shm_buf;
	int i;

	/*
	* don't lock the lower OTPs, no ECC protection and incremental
	* bit programming, a second write is allowed
	*/
	start = max_t(u32, offset, lower * 4);
	nb_lock = (offset + bytes - start) / 4;

	param[0].u.value.a = start;
	param[0].u.value.b = LOCK_ACCESS;
	param[1].u.memref.size = nb_lock * 4;

	for (i = 0; i < nb_lock; i++)
	lock[i] = LOCK_PERM;

	ret = tee_client_invoke_func(ctx, &arg, param);
	if (ret < 0 \|\| arg.ret != 0) {
	pr_err("TA_BSEC invoke failed TEE err:%#x, ret:%#x\n", arg.ret, ret);
	if (!ret)
	ret = -EIO;
	}
	pr_debug("Lock upper OTPs %d to %d, ret=%d\n",
	start / 4, start / 4 + nb_lock, ret);
	}

	tee_shm_free(shm);

	out_tee_session:
	stm32_bsec_ta_close_session(ctx, session_id);

	return ret;
	}