diff options
author | Patrick Delaunay <patrick.delaunay@foss.st.com> | 2023-02-06 14:43:51 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-02-06 19:06:59 +0100 |
commit | 6a0bc3522e746025e2d9a63ab2cb5d7062c2d39c (patch) | |
tree | cab3e920621ff93e6a73501f9b35e1ea0a0c2b13 /drivers/nvmem/stm32-bsec-optee-ta.c | |
parent | nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of() (diff) | |
download | linux-6a0bc3522e746025e2d9a63ab2cb5d7062c2d39c.tar.xz linux-6a0bc3522e746025e2d9a63ab2cb5d7062c2d39c.zip |
nvmem: stm32: add OP-TEE support for STM32MP13x
For boot with OP-TEE on STM32MP13, the communication with the secure
world no more use STMicroelectronics SMC but communication with the
STM32MP BSEC TA, for data access (read/write) or lock operation:
- all the request are sent to OP-TEE trusted application,
- for upper OTP with ECC protection and with word programming only
each OTP are permanently locked when programmed to avoid ECC error
on the second write operation
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-18-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem/stm32-bsec-optee-ta.c')
-rw-r--r-- | drivers/nvmem/stm32-bsec-optee-ta.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/nvmem/stm32-bsec-optee-ta.c b/drivers/nvmem/stm32-bsec-optee-ta.c new file mode 100644 index 000000000000..f89ce791dd12 --- /dev/null +++ b/drivers/nvmem/stm32-bsec-optee-ta.c @@ -0,0 +1,298 @@ +// 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(¶m, 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(¶m, 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; +} |