[PATCH v6 2/3] nvmem: stm32: add OP-TEE support for STM32MP13x
Srinivas Kandagatla
srinivas.kandagatla at linaro.org
Fri Jan 20 09:42:04 PST 2023
On 18/01/2023 17:29, Patrick Delaunay wrote:
> 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 at foss.st.com>
> Reviewed-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
Applied thanks,
--srini
>
> Changes in v6:
> - Add reviewed by Etienne Carierre review
>
> Changes in v5:
> - minor changes after Etienne Carierre review (comments,
> change %x to %#x, remove goto to out_tee_session)
>
> Changes in v4:
> - fixe warning reported by kernel test robot for 64 bits support in
> drivers/nvmem/stm32-bsec-optee-ta.c:260:18:
> warning: format '%d' expects argument of type 'int',
> but argument 4 has type 'size_t'
>
> Changes in v3:
> - add a separate file stm32-bsec-optee-ta.c with STM32MP BSEC TA
> communication functions to avoid #if in romem driver.
>
> Changes in v2:
> - rebase series on linux-next/master
> - minor update after V1 revue
> - add missing sentinel in stm32_romem_of_match()
> - reorder function and remove prototypes for stm32_bsec_pta... functions
> - change stm32_bsec_pta_find to static
> - add return value in dev_err()
> - cleanups some comments, which can be on one line
> - remove test on priv->ctx in stm32_bsec_pta_remove
> - add missing tee_shm_free(shm) in stm32_bsec_pta_write() when
> tee_shm_get_va failed
> - return error in stm32_bsec_pta_find when devm_add_action_or_reset failed
> - handle driver_register error in stm32_romem_init
>
> drivers/nvmem/Kconfig | 11 +
> drivers/nvmem/Makefile | 1 +
> drivers/nvmem/stm32-bsec-optee-ta.c | 298 ++++++++++++++++++++++++++++
> drivers/nvmem/stm32-bsec-optee-ta.h | 80 ++++++++
> drivers/nvmem/stm32-romem.c | 54 ++++-
> 5 files changed, 441 insertions(+), 3 deletions(-)
> create mode 100644 drivers/nvmem/stm32-bsec-optee-ta.c
> create mode 100644 drivers/nvmem/stm32-bsec-optee-ta.h
>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index 755f551426b5..4d262f69a073 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -290,9 +290,20 @@ config NVMEM_SPRD_EFUSE
> This driver can also be built as a module. If so, the module
> will be called nvmem-sprd-efuse.
>
> +config NVMEM_STM32_BSEC_OPTEE_TA
> + bool "STM32MP BSEC OP-TEE TA support for nvmem-stm32-romem driver"
> + depends on OPTEE
> + help
> + Say y here to enable the accesses to STM32MP SoC OTPs by the OP-TEE
> + trusted application STM32MP BSEC.
> +
> + This library is a used by stm32-romem driver or included in the module
> + called nvmem-stm32-romem.
> +
> config NVMEM_STM32_ROMEM
> tristate "STMicroelectronics STM32 factory-programmed memory support"
> depends on ARCH_STM32 || COMPILE_TEST
> + imply NVMEM_STM32_BSEC_OPTEE_TA
> help
> Say y here to enable read-only access for STMicroelectronics STM32
> factory-programmed memory area.
> diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> index fa80fe17e567..6a1efffa88f0 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_NVMEM_SPRD_EFUSE) += nvmem_sprd_efuse.o
> nvmem_sprd_efuse-y := sprd-efuse.o
> obj-$(CONFIG_NVMEM_STM32_ROMEM) += nvmem_stm32_romem.o
> nvmem_stm32_romem-y := stm32-romem.o
> +nvmem_stm32_romem-$(CONFIG_NVMEM_STM32_BSEC_OPTEE_TA) += stm32-bsec-optee-ta.o
> obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP) += nvmem_sunplus_ocotp.o
> nvmem_sunplus_ocotp-y := sunplus-ocotp.o
> obj-$(CONFIG_NVMEM_SUNXI_SID) += nvmem_sunxi_sid.o
> 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;
> +}
> diff --git a/drivers/nvmem/stm32-bsec-optee-ta.h b/drivers/nvmem/stm32-bsec-optee-ta.h
> new file mode 100644
> index 000000000000..3966a0535179
> --- /dev/null
> +++ b/drivers/nvmem/stm32-bsec-optee-ta.h
> @@ -0,0 +1,80 @@
> +/* 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
> + */
> +
> +#if IS_ENABLED(CONFIG_NVMEM_STM32_BSEC_OPTEE_TA)
> +/**
> + * stm32_bsec_optee_ta_open() - initialize the STM32 BSEC TA
> + * @ctx: the OP-TEE context on success
> + *
> + * Return:
> + * On success, 0. On failure, -errno.
> + */
> +int stm32_bsec_optee_ta_open(struct tee_context **ctx);
> +
> +/**
> + * stm32_bsec_optee_ta_close() - release the STM32 BSEC TA
> + * @ctx: the OP-TEE context
> + *
> + * This function used to clean the OP-TEE resources initialized in
> + * stm32_bsec_optee_ta_open(); it can be used as callback to
> + * devm_add_action_or_reset()
> + */
> +void stm32_bsec_optee_ta_close(void *ctx);
> +
> +/**
> + * stm32_bsec_optee_ta_read() - nvmem read access using TA client driver
> + * @ctx: the OP-TEE context provided by stm32_bsec_optee_ta_open
> + * @offset: nvmem offset
> + * @buf: buffer to fill with nvem values
> + * @bytes: number of bytes to read
> + *
> + * Return:
> + * On success, 0. On failure, -errno.
> + */
> +int stm32_bsec_optee_ta_read(struct tee_context *ctx, unsigned int offset,
> + void *buf, size_t bytes);
> +
> +/**
> + * stm32_bsec_optee_ta_write() - nvmem write access using TA client driver
> + * @ctx: the OP-TEE context provided by stm32_bsec_optee_ta_open
> + * @lower: number of lower OTP, not protected by ECC
> + * @offset: nvmem offset
> + * @buf: buffer with nvem values
> + * @bytes: number of bytes to write
> + *
> + * Return:
> + * On success, 0. On failure, -errno.
> + */
> +int stm32_bsec_optee_ta_write(struct tee_context *ctx, unsigned int lower,
> + unsigned int offset, void *buf, size_t bytes);
> +
> +#else
> +
> +static inline int stm32_bsec_optee_ta_open(struct tee_context **ctx)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline void stm32_bsec_optee_ta_close(void *ctx)
> +{
> +}
> +
> +static inline int stm32_bsec_optee_ta_read(struct tee_context *ctx,
> + unsigned int offset, void *buf,
> + size_t bytes)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int stm32_bsec_optee_ta_write(struct tee_context *ctx,
> + unsigned int lower,
> + unsigned int offset, void *buf,
> + size_t bytes)
> +{
> + return -EOPNOTSUPP;
> +}
> +#endif /* CONFIG_NVMEM_STM32_BSEC_OPTEE_TA */
> diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c
> index d1d03c2ad081..978a63edf297 100644
> --- a/drivers/nvmem/stm32-romem.c
> +++ b/drivers/nvmem/stm32-romem.c
> @@ -11,6 +11,9 @@
> #include <linux/module.h>
> #include <linux/nvmem-provider.h>
> #include <linux/of_device.h>
> +#include <linux/tee_drv.h>
> +
> +#include "stm32-bsec-optee-ta.h"
>
> /* BSEC secure service access from non-secure */
> #define STM32_SMC_BSEC 0x82001003
> @@ -25,12 +28,14 @@
> struct stm32_romem_cfg {
> int size;
> u8 lower;
> + bool ta;
> };
>
> struct stm32_romem_priv {
> void __iomem *base;
> struct nvmem_config cfg;
> u8 lower;
> + struct tee_context *ctx;
> };
>
> static int stm32_romem_read(void *context, unsigned int offset, void *buf,
> @@ -138,12 +143,29 @@ static int stm32_bsec_write(void *context, unsigned int offset, void *buf,
> return 0;
> }
>
> +static int stm32_bsec_pta_read(void *context, unsigned int offset, void *buf,
> + size_t bytes)
> +{
> + struct stm32_romem_priv *priv = context;
> +
> + return stm32_bsec_optee_ta_read(priv->ctx, offset, buf, bytes);
> +}
> +
> +static int stm32_bsec_pta_write(void *context, unsigned int offset, void *buf,
> + size_t bytes)
> +{
> + struct stm32_romem_priv *priv = context;
> +
> + return stm32_bsec_optee_ta_write(priv->ctx, priv->lower, offset, buf, bytes);
> +}
> +
> static int stm32_romem_probe(struct platform_device *pdev)
> {
> const struct stm32_romem_cfg *cfg;
> struct device *dev = &pdev->dev;
> struct stm32_romem_priv *priv;
> struct resource *res;
> + int rc;
>
> priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -173,15 +195,31 @@ static int stm32_romem_probe(struct platform_device *pdev)
> } else {
> priv->cfg.size = cfg->size;
> priv->lower = cfg->lower;
> - priv->cfg.reg_read = stm32_bsec_read;
> - priv->cfg.reg_write = stm32_bsec_write;
> + if (cfg->ta) {
> + rc = stm32_bsec_optee_ta_open(&priv->ctx);
> + /* wait for OP-TEE client driver to be up and ready */
> + if (rc)
> + return rc;
> + }
> + if (priv->ctx) {
> + rc = devm_add_action_or_reset(dev, stm32_bsec_optee_ta_close, priv->ctx);
> + if (rc) {
> + dev_err(dev, "devm_add_action_or_reset() failed (%d)\n", rc);
> + return rc;
> + }
> + priv->cfg.reg_read = stm32_bsec_pta_read;
> + priv->cfg.reg_write = stm32_bsec_pta_write;
> + } else {
> + priv->cfg.reg_read = stm32_bsec_read;
> + priv->cfg.reg_write = stm32_bsec_write;
> + }
> }
>
> return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &priv->cfg));
> }
>
> /*
> - * STM32MP15 BSEC OTP regions: 4096 OTP bits (with 3072 effective bits)
> + * STM32MP15/13 BSEC OTP regions: 4096 OTP bits (with 3072 effective bits)
> * => 96 x 32-bits data words
> * - Lower: 1K bits, 2:1 redundancy, incremental bit programming
> * => 32 (x 32-bits) lower shadow registers = words 0 to 31
> @@ -191,6 +229,13 @@ static int stm32_romem_probe(struct platform_device *pdev)
> static const struct stm32_romem_cfg stm32mp15_bsec_cfg = {
> .size = 384,
> .lower = 32,
> + .ta = false,
> +};
> +
> +static const struct stm32_romem_cfg stm32mp13_bsec_cfg = {
> + .size = 384,
> + .lower = 32,
> + .ta = true,
> };
>
> static const struct of_device_id stm32_romem_of_match[] = {
> @@ -198,7 +243,10 @@ static const struct of_device_id stm32_romem_of_match[] = {
> .compatible = "st,stm32mp15-bsec",
> .data = (void *)&stm32mp15_bsec_cfg,
> }, {
> + .compatible = "st,stm32mp13-bsec",
> + .data = (void *)&stm32mp13_bsec_cfg,
> },
> + { /* sentinel */ },
> };
> MODULE_DEVICE_TABLE(of, stm32_romem_of_match);
>
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