diff options
| -rw-r--r-- | drivers/firmware/arm_scmi/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 3 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 3 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/optee.c | 581 |
5 files changed, 600 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig index 3d7081e84853..da1daa593204 100644 --- a/drivers/firmware/arm_scmi/Kconfig +++ b/drivers/firmware/arm_scmi/Kconfig @@ -54,6 +54,18 @@ config ARM_SCMI_TRANSPORT_MAILBOX If you want the ARM SCMI PROTOCOL stack to include support for a transport based on mailboxes, answer Y. +config ARM_SCMI_TRANSPORT_OPTEE + bool "SCMI transport based on OP-TEE service" + depends on OPTEE=y || OPTEE=ARM_SCMI_PROTOCOL + select ARM_SCMI_HAVE_TRANSPORT + select ARM_SCMI_HAVE_SHMEM + default y + help + This enables the OP-TEE service based transport for SCMI. + + If you want the ARM SCMI PROTOCOL stack to include support for a + transport based on OP-TEE SCMI service, answer Y. + config ARM_SCMI_TRANSPORT_SMC bool "SCMI transport based on SMC" depends on HAVE_ARM_SMCCC_DISCOVERY diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile index 1dcf123d64ab..ef66ec8ca917 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile @@ -6,6 +6,7 @@ scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += virtio.o +scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) += optee.o scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \ $(scmi-transport-y) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index dea1bfbe1052..6438b5248c24 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -421,6 +421,9 @@ extern const struct scmi_desc scmi_smc_desc; #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO extern const struct scmi_desc scmi_virtio_desc; #endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE +extern const struct scmi_desc scmi_optee_desc; +#endif void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index b406b3f78f46..768926a77f5d 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1994,6 +1994,9 @@ static const struct of_device_id scmi_of_match[] = { #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, #endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE + { .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc }, +#endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, #endif diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c new file mode 100644 index 000000000000..d9819b0197ec --- /dev/null +++ b/drivers/firmware/arm_scmi/optee.c @@ -0,0 +1,581 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019-2021 Linaro Ltd. + */ + +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/tee_drv.h> +#include <linux/uuid.h> +#include <uapi/linux/tee.h> + +#include "common.h" + +#define SCMI_OPTEE_MAX_MSG_SIZE 128 + +enum scmi_optee_pta_cmd { + /* + * PTA_SCMI_CMD_CAPABILITIES - Get channel capabilities + * + * [out] value[0].a: Capability bit mask (enum pta_scmi_caps) + * [out] value[0].b: Extended capabilities or 0 + */ + PTA_SCMI_CMD_CAPABILITIES = 0, + + /* + * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL - Process SCMI message in SMT buffer + * + * [in] value[0].a: Channel handle + * + * Shared memory used for SCMI message/response exhange is expected + * already identified and bound to channel handle in both SCMI agent + * and SCMI server (OP-TEE) parts. + * The memory uses SMT header to carry SCMI meta-data (protocol ID and + * protocol message ID). + */ + PTA_SCMI_CMD_PROCESS_SMT_CHANNEL = 1, + + /* + * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE - Process SMT/SCMI message + * + * [in] value[0].a: Channel handle + * [in/out] memref[1]: Message/response buffer (SMT and SCMI payload) + * + * Shared memory used for SCMI message/response is a SMT buffer + * referenced by param[1]. It shall be 128 bytes large to fit response + * payload whatever message playload size. + * The memory uses SMT header to carry SCMI meta-data (protocol ID and + * protocol message ID). + */ + PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE = 2, + + /* + * PTA_SCMI_CMD_GET_CHANNEL - Get channel handle + * + * SCMI shm information are 0 if agent expects to use OP-TEE regular SHM + * + * [in] value[0].a: Channel identifier + * [out] value[0].a: Returned channel handle + * [in] value[0].b: Requested capabilities mask (enum pta_scmi_caps) + */ + PTA_SCMI_CMD_GET_CHANNEL = 3, +}; + +/* + * OP-TEE SCMI service capabilities bit flags (32bit) + * + * PTA_SCMI_CAPS_SMT_HEADER + * When set, OP-TEE supports command using SMT header protocol (SCMI shmem) in + * shared memory buffers to carry SCMI protocol synchronisation information. + */ +#define PTA_SCMI_CAPS_NONE 0 +#define PTA_SCMI_CAPS_SMT_HEADER BIT(0) + +/** + * struct scmi_optee_channel - Description of an OP-TEE SCMI channel + * + * @channel_id: OP-TEE channel ID used for this transport + * @tee_session: TEE session identifier + * @caps: OP-TEE SCMI channel capabilities + * @mu: Mutex protection on channel access + * @cinfo: SCMI channel information + * @shmem: Virtual base address of the shared memory + * @tee_shm: Reference to TEE shared memory or NULL if using static shmem + * @link: Reference in agent's channel list + */ +struct scmi_optee_channel { + u32 channel_id; + u32 tee_session; + u32 caps; + struct mutex mu; + struct scmi_chan_info *cinfo; + struct scmi_shared_mem __iomem *shmem; + struct tee_shm *tee_shm; + struct list_head link; +}; + +/** + * struct scmi_optee_agent - OP-TEE transport private data + * + * @dev: Device used for communication with TEE + * @tee_ctx: TEE context used for communication + * @caps: Supported channel capabilities + * @mu: Mutex for protection of @channel_list + * @channel_list: List of all created channels for the agent + */ +struct scmi_optee_agent { + struct device *dev; + struct tee_context *tee_ctx; + u32 caps; + struct mutex mu; + struct list_head channel_list; +}; + +/* There can be only 1 SCMI service in OP-TEE we connect to */ +static struct scmi_optee_agent *scmi_optee_private; + +/* Forward reference to scmi_optee transport initialization */ +static int scmi_optee_init(void); + +/* Open a session toward SCMI OP-TEE service with REE_KERNEL identity */ +static int open_session(struct scmi_optee_agent *agent, u32 *tee_session) +{ + struct device *dev = agent->dev; + struct tee_client_device *scmi_pta = to_tee_client_device(dev); + struct tee_ioctl_open_session_arg arg = { }; + int ret; + + memcpy(arg.uuid, scmi_pta->id.uuid.b, TEE_IOCTL_UUID_LEN); + arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + + ret = tee_client_open_session(agent->tee_ctx, &arg, NULL); + if (ret < 0 || arg.ret) { + dev_err(dev, "Can't open tee session: %d / %#x\n", ret, arg.ret); + return -EOPNOTSUPP; + } + + *tee_session = arg.session; + + return 0; +} + +static void close_session(struct scmi_optee_agent *agent, u32 tee_session) +{ + tee_client_close_session(agent->tee_ctx, tee_session); +} + +static int get_capabilities(struct scmi_optee_agent *agent) +{ + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[1] = { }; + u32 caps; + u32 tee_session; + int ret; + + ret = open_session(agent, &tee_session); + if (ret) + return ret; + + arg.func = PTA_SCMI_CMD_CAPABILITIES; + arg.session = tee_session; + arg.num_params = 1; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT; + + ret = tee_client_invoke_func(agent->tee_ctx, &arg, param); + + close_session(agent, tee_session); + + if (ret < 0 || arg.ret) { + dev_err(agent->dev, "Can't get capabilities: %d / %#x\n", ret, arg.ret); + return -EOPNOTSUPP; + } + + caps = param[0].u.value.a; + + if (!(caps & PTA_SCMI_CAPS_SMT_HEADER)) { + dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT\n"); + return -EOPNOTSUPP; + } + + agent->caps = caps; + + return 0; +} + +static int get_channel(struct scmi_optee_channel *channel) +{ + struct device *dev = scmi_optee_private->dev; + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[1] = { }; + unsigned int caps = PTA_SCMI_CAPS_SMT_HEADER; + int ret; + + arg.func = PTA_SCMI_CMD_GET_CHANNEL; + arg.session = channel->tee_session; + arg.num_params = 1; + + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT; + param[0].u.value.a = channel->channel_id; + param[0].u.value.b = caps; + + ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param); + + if (ret || arg.ret) { + dev_err(dev, "Can't get channel with caps %#x: %d / %#x\n", caps, ret, arg.ret); + return -EOPNOTSUPP; + } + + /* From now on use channel identifer provided by OP-TEE SCMI service */ + channel->channel_id = param[0].u.value.a; + channel->caps = caps; + + return 0; +} + +static int invoke_process_smt_channel(struct scmi_optee_channel *channel) +{ + struct tee_ioctl_invoke_arg arg = { }; + struct tee_param param[2] = { }; + int ret; + + arg.session = channel->tee_session; + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT; + param[0].u.value.a = channel->channel_id; + + if (channel->tee_shm) { + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT; + param[1].u.memref.shm = channel->tee_shm; + param[1].u.memref.size = SCMI_OPTEE_MAX_MSG_SIZE; + arg.num_params = 2; + arg.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE; + } else { + arg.num_params = 1; + arg.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL; + } + + ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param); + if (ret < 0 || arg.ret) { + dev_err(scmi_optee_private->dev, "Can't invoke channel %u: %d / %#x\n", + channel->channel_id, ret, arg.ret); + return -EIO; + } + + return 0; +} + +static int scmi_optee_link_supplier(struct device *dev) +{ + if (!scmi_optee_private) { + if (scmi_optee_init()) + dev_dbg(dev, "Optee bus not yet ready\n"); + + /* Wait for optee bus */ + return -EPROBE_DEFER; + } + + if (!device_link_add(dev, scmi_optee_private->dev, DL_FLAG_AUTOREMOVE_CONSUMER)) { + dev_err(dev, "Adding link to supplier optee device failed\n"); + return -ECANCELED; + } + + return 0; +} + +static bool scmi_optee_chan_available(struct device *dev, int idx) +{ + u32 channel_id; + + return !of_property_read_u32_index(dev->of_node, "linaro,optee-channel-id", + idx, &channel_id); +} + +static void scmi_optee_clear_channel(struct scmi_chan_info *cinfo) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + + shmem_clear_channel(channel->shmem); +} + +static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *channel) +{ + const size_t msg_size = SCMI_OPTEE_MAX_MSG_SIZE; + + channel->tee_shm = tee_shm_alloc_kernel_buf(scmi_optee_private->tee_ctx, msg_size); + if (IS_ERR(channel->tee_shm)) { + dev_err(channel->cinfo->dev, "shmem allocation failed\n"); + return -ENOMEM; + } + + channel->shmem = (void *)tee_shm_get_va(channel->tee_shm, 0); + memset(channel->shmem, 0, msg_size); + shmem_clear_channel(channel->shmem); + + return 0; +} + +static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo, + struct scmi_optee_channel *channel) +{ + struct device_node *np; + resource_size_t size; + struct resource res; + int ret; + + np = of_parse_phandle(cinfo->dev->of_node, "shmem", 0); + if (!of_device_is_compatible(np, "arm,scmi-shmem")) { + ret = -ENXIO; + goto out; + } + + ret = of_address_to_resource(np, 0, &res); + if (ret) { + dev_err(dev, "Failed to get SCMI Tx shared memory\n"); + goto out; + } + + size = resource_size(&res); + + channel->shmem = devm_ioremap(dev, res.start, size); + if (!channel->shmem) { + dev_err(dev, "Failed to ioremap SCMI Tx shared memory\n"); + ret = -EADDRNOTAVAIL; + goto out; + } + + ret = 0; + +out: + of_node_put(np); + + return ret; +} + +static int setup_shmem(struct device *dev, struct scmi_chan_info *cinfo, + struct scmi_optee_channel *channel) +{ + if (of_find_property(cinfo->dev->of_node, "shmem", NULL)) + return setup_static_shmem(dev, cinfo, channel); + else + return setup_dynamic_shmem(dev, channel); +} + +static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx) +{ + struct scmi_optee_channel *channel; + uint32_t channel_id; + int ret; + + if (!tx) + return -ENODEV; + + channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL); + if (!channel) + return -ENOMEM; + + ret = of_property_read_u32_index(cinfo->dev->of_node, "linaro,optee-channel-id", + 0, &channel_id); + if (ret) + return ret; + + cinfo->transport_info = channel; + channel->cinfo = cinfo; + channel->channel_id = channel_id; + mutex_init(&channel->mu); + + ret = setup_shmem(dev, cinfo, channel); + if (ret) + return ret; + + ret = open_session(scmi_optee_private, &channel->tee_session); + if (ret) + goto err_free_shm; + + ret = get_channel(channel); + if (ret) + goto err_close_sess; + + mutex_lock(&scmi_optee_private->mu); + list_add(&channel->link, &scmi_optee_private->channel_list); + mutex_unlock(&scmi_optee_private->mu); + + return 0; + +err_close_sess: + close_session(scmi_optee_private, channel->tee_session); +err_free_shm: + if (channel->tee_shm) + tee_shm_free(channel->tee_shm); + + return ret; +} + +static int scmi_optee_chan_free(int id, void *p, void *data) +{ + struct scmi_chan_info *cinfo = p; + struct scmi_optee_channel *channel = cinfo->transport_info; + + mutex_lock(&scmi_optee_private->mu); + list_del(&channel->link); + mutex_unlock(&scmi_optee_private->mu); + + close_session(scmi_optee_private, channel->tee_session); + + if (channel->tee_shm) { + tee_shm_free(channel->tee_shm); + channel->tee_shm = NULL; + } + + cinfo->transport_info = NULL; + channel->cinfo = NULL; + + scmi_free_channel(cinfo, data, id); + + return 0; +} + +static struct scmi_shared_mem *get_channel_shm(struct scmi_optee_channel *chan, + struct scmi_xfer *xfer) +{ + if (!chan) + return NULL; + + return chan->shmem; +} + + +static int scmi_optee_send_message(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer); + int ret; + + mutex_lock(&channel->mu); + shmem_tx_prepare(shmem, xfer); + + ret = invoke_process_smt_channel(channel); + + scmi_rx_callback(cinfo, shmem_read_header(shmem), NULL); + mutex_unlock(&channel->mu); + + return ret; +} + +static void scmi_optee_fetch_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer); + + shmem_fetch_response(shmem, xfer); +} + +static bool scmi_optee_poll_done(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_optee_channel *channel = cinfo->transport_info; + struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer); + + return shmem_poll_done(shmem, xfer); +} + +static struct scmi_transport_ops scmi_optee_ops = { + .link_supplier = scmi_optee_link_supplier, + .chan_available = scmi_optee_chan_available, + .chan_setup = scmi_optee_chan_setup, + .chan_free = scmi_optee_chan_free, + .send_message = scmi_optee_send_message, + .fetch_response = scmi_optee_fetch_response, + .clear_channel = scmi_optee_clear_channel, + .poll_done = scmi_optee_poll_done, +}; + +static int scmi_optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + return ver->impl_id == TEE_IMPL_ID_OPTEE; +} + +static int scmi_optee_service_probe(struct device *dev) +{ + struct scmi_optee_agent *agent; + struct tee_context *tee_ctx; + int ret; + + /* Only one SCMI OP-TEE device allowed */ + if (scmi_optee_private) { + dev_err(dev, "An SCMI OP-TEE device was already initialized: only one allowed\n"); + return -EBUSY; + } + + tee_ctx = tee_client_open_context(NULL, scmi_optee_ctx_match, NULL, NULL); + if (IS_ERR(tee_ctx)) + return -ENODEV; + + agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL); + if (!agent) { + ret = -ENOMEM; + goto err; + } + + agent->dev = dev; + agent->tee_ctx = tee_ctx; + INIT_LIST_HEAD(&agent->channel_list); + + ret = get_capabilities(agent); + if (ret) + goto err; + + /* Ensure agent resources are all visible before scmi_optee_private is */ + smp_mb(); + scmi_optee_private = agent; + + return 0; + +err: + tee_client_close_context(tee_ctx); + + return ret; +} + +static int scmi_optee_service_remove(struct device *dev) +{ + struct scmi_optee_agent *agent = scmi_optee_private; + + if (!scmi_optee_private) + return -EINVAL; + + if (!list_empty(&scmi_optee_private->channel_list)) + return -EBUSY; + + /* Ensure cleared reference is visible before resources are released */ + smp_store_mb(scmi_optee_private, NULL); + + tee_client_close_context(agent->tee_ctx); + + return 0; +} + +static const struct tee_client_device_id scmi_optee_service_id[] = { + { + UUID_INIT(0xa8cfe406, 0xd4f5, 0x4a2e, + 0x9f, 0x8d, 0xa2, 0x5d, 0xc7, 0x54, 0xc0, 0x99) + }, + { } +}; + +MODULE_DEVICE_TABLE(tee, scmi_optee_service_id); + +static struct tee_client_driver scmi_optee_driver = { + .id_table = scmi_optee_service_id, + .driver = { + .name = "scmi-optee", + .bus = &tee_bus_type, + .probe = scmi_optee_service_probe, + .remove = scmi_optee_service_remove, + }, +}; + +static int scmi_optee_init(void) +{ + return driver_register(&scmi_optee_driver.driver); +} + +static void scmi_optee_exit(void) +{ + if (scmi_optee_private) + driver_unregister(&scmi_optee_driver.driver); +} + +const struct scmi_desc scmi_optee_desc = { + .transport_exit = scmi_optee_exit, + .ops = &scmi_optee_ops, + .max_rx_timeout_ms = 30, + .max_msg = 20, + .max_msg_size = SCMI_OPTEE_MAX_MSG_SIZE, +}; |