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path: root/drivers/firmware/arm_scmi/optee.c
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Diffstat (limited to 'drivers/firmware/arm_scmi/optee.c')
-rw-r--r--drivers/firmware/arm_scmi/optee.c645
1 files changed, 645 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
new file mode 100644
index 000000000..2a7aeab40
--- /dev/null
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -0,0 +1,645 @@
+// 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,
+
+ /*
+ * PTA_SCMI_CMD_PROCESS_MSG_CHANNEL - Process SCMI message in a MSG
+ * buffer pointed by memref parameters
+ *
+ * [in] value[0].a: Channel handle
+ * [in] memref[1]: Message buffer (MSG and SCMI payload)
+ * [out] memref[2]: Response buffer (MSG and SCMI payload)
+ *
+ * Shared memories used for SCMI message/response are MSG buffers
+ * referenced by param[1] and param[2]. MSG transport protocol
+ * uses a 32bit header to carry SCMI meta-data (protocol ID and
+ * protocol message ID) followed by the effective SCMI message
+ * payload.
+ */
+ PTA_SCMI_CMD_PROCESS_MSG_CHANNEL = 4,
+};
+
+/*
+ * 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.
+ *
+ * PTA_SCMI_CAPS_MSG_HEADER
+ * When set, OP-TEE supports command using MSG header protocol in an OP-TEE
+ * shared memory to carry SCMI protocol synchronisation information and SCMI
+ * message payload.
+ */
+#define PTA_SCMI_CAPS_NONE 0
+#define PTA_SCMI_CAPS_SMT_HEADER BIT(0)
+#define PTA_SCMI_CAPS_MSG_HEADER BIT(1)
+#define PTA_SCMI_CAPS_MASK (PTA_SCMI_CAPS_SMT_HEADER | \
+ PTA_SCMI_CAPS_MSG_HEADER)
+
+/**
+ * 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
+ * @rx_len: Response size
+ * @mu: Mutex protection on channel access
+ * @cinfo: SCMI channel information
+ * @shmem: Virtual base address of the shared memory
+ * @req: Shared memory protocol handle for SCMI request and synchronous response
+ * @tee_shm: TEE shared memory handle @req or NULL if using IOMEM shmem
+ * @link: Reference in agent's channel list
+ */
+struct scmi_optee_channel {
+ u32 channel_id;
+ u32 tee_session;
+ u32 caps;
+ u32 rx_len;
+ struct mutex mu;
+ struct scmi_chan_info *cinfo;
+ union {
+ struct scmi_shared_mem __iomem *shmem;
+ struct scmi_msg_payld *msg;
+ } req;
+ 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 | PTA_SCMI_CAPS_MSG_HEADER))) {
+ dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT and MSG\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 = 0;
+ int ret;
+
+ if (channel->tee_shm)
+ caps = PTA_SCMI_CAPS_MSG_HEADER;
+ else
+ caps = PTA_SCMI_CAPS_SMT_HEADER;
+
+ 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 = {
+ .func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL,
+ .session = channel->tee_session,
+ .num_params = 1,
+ };
+ struct tee_param param[1] = { };
+ int ret;
+
+ param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+ param[0].u.value.a = channel->channel_id;
+
+ 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 invoke_process_msg_channel(struct scmi_optee_channel *channel, size_t msg_size)
+{
+ struct tee_ioctl_invoke_arg arg = {
+ .func = PTA_SCMI_CMD_PROCESS_MSG_CHANNEL,
+ .session = channel->tee_session,
+ .num_params = 3,
+ };
+ struct tee_param param[3] = { };
+ int ret;
+
+ param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+ param[0].u.value.a = channel->channel_id;
+
+ param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+ param[1].u.memref.shm = channel->tee_shm;
+ param[1].u.memref.size = msg_size;
+
+ param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+ param[2].u.memref.shm = channel->tee_shm;
+ param[2].u.memref.size = SCMI_OPTEE_MAX_MSG_SIZE;
+
+ 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;
+ }
+
+ /* Save response size */
+ channel->rx_len = param[2].u.memref.size;
+
+ 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;
+
+ if (!channel->tee_shm)
+ shmem_clear_channel(channel->req.shmem);
+}
+
+static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *channel)
+{
+ const size_t msg_size = SCMI_OPTEE_MAX_MSG_SIZE;
+ void *shbuf;
+
+ 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;
+ }
+
+ shbuf = tee_shm_get_va(channel->tee_shm, 0);
+ memset(shbuf, 0, msg_size);
+ channel->req.msg = shbuf;
+ channel->rx_len = msg_size;
+
+ 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->req.shmem = devm_ioremap(dev, res.start, size);
+ if (!channel->req.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;
+
+ /* Enable polling */
+ cinfo->no_completion_irq = true;
+
+ 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 int scmi_optee_send_message(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct scmi_optee_channel *channel = cinfo->transport_info;
+ int ret;
+
+ mutex_lock(&channel->mu);
+
+ if (channel->tee_shm) {
+ msg_tx_prepare(channel->req.msg, xfer);
+ ret = invoke_process_msg_channel(channel, msg_command_size(xfer));
+ } else {
+ shmem_tx_prepare(channel->req.shmem, xfer, cinfo);
+ ret = invoke_process_smt_channel(channel);
+ }
+
+ if (ret)
+ 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;
+
+ if (channel->tee_shm)
+ msg_fetch_response(channel->req.msg, channel->rx_len, xfer);
+ else
+ shmem_fetch_response(channel->req.shmem, xfer);
+}
+
+static void scmi_optee_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+ struct scmi_xfer *__unused)
+{
+ struct scmi_optee_channel *channel = cinfo->transport_info;
+
+ mutex_unlock(&channel->mu);
+}
+
+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,
+ .mark_txdone = scmi_optee_mark_txdone,
+ .fetch_response = scmi_optee_fetch_response,
+ .clear_channel = scmi_optee_clear_channel,
+};
+
+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);
+ mutex_init(&agent->mu);
+
+ 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,
+ .sync_cmds_completed_on_ret = true,
+};