diff options
Diffstat (limited to 'drivers/firmware/qcom_scm.c')
| -rw-r--r-- | drivers/firmware/qcom_scm.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index 06fe8aca870d..f9d5c31b8ec7 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -55,6 +55,53 @@ struct qcom_scm_mem_map_info { __le64 mem_size; }; +/** + * struct qcom_scm_qseecom_resp - QSEECOM SCM call response. + * @result: Result or status of the SCM call. See &enum qcom_scm_qseecom_result. + * @resp_type: Type of the response. See &enum qcom_scm_qseecom_resp_type. + * @data: Response data. The type of this data is given in @resp_type. + */ +struct qcom_scm_qseecom_resp { + u64 result; + u64 resp_type; + u64 data; +}; + +enum qcom_scm_qseecom_result { + QSEECOM_RESULT_SUCCESS = 0, + QSEECOM_RESULT_INCOMPLETE = 1, + QSEECOM_RESULT_BLOCKED_ON_LISTENER = 2, + QSEECOM_RESULT_FAILURE = 0xFFFFFFFF, +}; + +enum qcom_scm_qseecom_resp_type { + QSEECOM_SCM_RES_APP_ID = 0xEE01, + QSEECOM_SCM_RES_QSEOS_LISTENER_ID = 0xEE02, +}; + +enum qcom_scm_qseecom_tz_owner { + QSEECOM_TZ_OWNER_SIP = 2, + QSEECOM_TZ_OWNER_TZ_APPS = 48, + QSEECOM_TZ_OWNER_QSEE_OS = 50 +}; + +enum qcom_scm_qseecom_tz_svc { + QSEECOM_TZ_SVC_APP_ID_PLACEHOLDER = 0, + QSEECOM_TZ_SVC_APP_MGR = 1, + QSEECOM_TZ_SVC_INFO = 6, +}; + +enum qcom_scm_qseecom_tz_cmd_app { + QSEECOM_TZ_CMD_APP_SEND = 1, + QSEECOM_TZ_CMD_APP_LOOKUP = 3, +}; + +enum qcom_scm_qseecom_tz_cmd_info { + QSEECOM_TZ_CMD_INFO_VERSION = 3, +}; + +#define QSEECOM_MAX_APP_NAME_SIZE 64 + /* Each bit configures cold/warm boot address for one of the 4 CPUs */ static const u8 qcom_scm_cpu_cold_bits[QCOM_SCM_BOOT_MAX_CPUS] = { 0, BIT(0), BIT(3), BIT(5) @@ -1321,6 +1368,340 @@ static int qcom_scm_find_dload_address(struct device *dev, u64 *addr) return 0; } +#ifdef CONFIG_QCOM_QSEECOM + +/* Lock for QSEECOM SCM call executions */ +static DEFINE_MUTEX(qcom_scm_qseecom_call_lock); + +static int __qcom_scm_qseecom_call(const struct qcom_scm_desc *desc, + struct qcom_scm_qseecom_resp *res) +{ + struct qcom_scm_res scm_res = {}; + int status; + + /* + * QSEECOM SCM calls should not be executed concurrently. Therefore, we + * require the respective call lock to be held. + */ + lockdep_assert_held(&qcom_scm_qseecom_call_lock); + + status = qcom_scm_call(__scm->dev, desc, &scm_res); + + res->result = scm_res.result[0]; + res->resp_type = scm_res.result[1]; + res->data = scm_res.result[2]; + + if (status) + return status; + + return 0; +} + +/** + * qcom_scm_qseecom_call() - Perform a QSEECOM SCM call. + * @desc: SCM call descriptor. + * @res: SCM call response (output). + * + * Performs the QSEECOM SCM call described by @desc, returning the response in + * @rsp. + * + * Return: Zero on success, nonzero on failure. + */ +static int qcom_scm_qseecom_call(const struct qcom_scm_desc *desc, + struct qcom_scm_qseecom_resp *res) +{ + int status; + + /* + * Note: Multiple QSEECOM SCM calls should not be executed same time, + * so lock things here. This needs to be extended to callback/listener + * handling when support for that is implemented. + */ + + mutex_lock(&qcom_scm_qseecom_call_lock); + status = __qcom_scm_qseecom_call(desc, res); + mutex_unlock(&qcom_scm_qseecom_call_lock); + + dev_dbg(__scm->dev, "%s: owner=%x, svc=%x, cmd=%x, result=%lld, type=%llx, data=%llx\n", + __func__, desc->owner, desc->svc, desc->cmd, res->result, + res->resp_type, res->data); + + if (status) { + dev_err(__scm->dev, "qseecom: scm call failed with error %d\n", status); + return status; + } + + /* + * TODO: Handle incomplete and blocked calls: + * + * Incomplete and blocked calls are not supported yet. Some devices + * and/or commands require those, some don't. Let's warn about them + * prominently in case someone attempts to try these commands with a + * device/command combination that isn't supported yet. + */ + WARN_ON(res->result == QSEECOM_RESULT_INCOMPLETE); + WARN_ON(res->result == QSEECOM_RESULT_BLOCKED_ON_LISTENER); + + return 0; +} + +/** + * qcom_scm_qseecom_get_version() - Query the QSEECOM version. + * @version: Pointer where the QSEECOM version will be stored. + * + * Performs the QSEECOM SCM querying the QSEECOM version currently running in + * the TrustZone. + * + * Return: Zero on success, nonzero on failure. + */ +static int qcom_scm_qseecom_get_version(u32 *version) +{ + struct qcom_scm_desc desc = {}; + struct qcom_scm_qseecom_resp res = {}; + u32 feature = 10; + int ret; + + desc.owner = QSEECOM_TZ_OWNER_SIP; + desc.svc = QSEECOM_TZ_SVC_INFO; + desc.cmd = QSEECOM_TZ_CMD_INFO_VERSION; + desc.arginfo = QCOM_SCM_ARGS(1, QCOM_SCM_VAL); + desc.args[0] = feature; + + ret = qcom_scm_qseecom_call(&desc, &res); + if (ret) + return ret; + + *version = res.result; + return 0; +} + +/** + * qcom_scm_qseecom_app_get_id() - Query the app ID for a given QSEE app name. + * @app_name: The name of the app. + * @app_id: The returned app ID. + * + * Query and return the application ID of the SEE app identified by the given + * name. This returned ID is the unique identifier of the app required for + * subsequent communication. + * + * Return: Zero on success, nonzero on failure, -ENOENT if the app has not been + * loaded or could not be found. + */ +int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id) +{ + unsigned long name_buf_size = QSEECOM_MAX_APP_NAME_SIZE; + unsigned long app_name_len = strlen(app_name); + struct qcom_scm_desc desc = {}; + struct qcom_scm_qseecom_resp res = {}; + dma_addr_t name_buf_phys; + char *name_buf; + int status; + + if (app_name_len >= name_buf_size) + return -EINVAL; + + name_buf = kzalloc(name_buf_size, GFP_KERNEL); + if (!name_buf) + return -ENOMEM; + + memcpy(name_buf, app_name, app_name_len); + + name_buf_phys = dma_map_single(__scm->dev, name_buf, name_buf_size, DMA_TO_DEVICE); + status = dma_mapping_error(__scm->dev, name_buf_phys); + if (status) { + kfree(name_buf); + dev_err(__scm->dev, "qseecom: failed to map dma address\n"); + return status; + } + + desc.owner = QSEECOM_TZ_OWNER_QSEE_OS; + desc.svc = QSEECOM_TZ_SVC_APP_MGR; + desc.cmd = QSEECOM_TZ_CMD_APP_LOOKUP; + desc.arginfo = QCOM_SCM_ARGS(2, QCOM_SCM_RW, QCOM_SCM_VAL); + desc.args[0] = name_buf_phys; + desc.args[1] = app_name_len; + + status = qcom_scm_qseecom_call(&desc, &res); + dma_unmap_single(__scm->dev, name_buf_phys, name_buf_size, DMA_TO_DEVICE); + kfree(name_buf); + + if (status) + return status; + + if (res.result == QSEECOM_RESULT_FAILURE) + return -ENOENT; + + if (res.result != QSEECOM_RESULT_SUCCESS) + return -EINVAL; + + if (res.resp_type != QSEECOM_SCM_RES_APP_ID) + return -EINVAL; + + *app_id = res.data; + return 0; +} +EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_get_id); + +/** + * qcom_scm_qseecom_app_send() - Send to and receive data from a given QSEE app. + * @app_id: The ID of the target app. + * @req: Request buffer sent to the app (must be DMA-mappable). + * @req_size: Size of the request buffer. + * @rsp: Response buffer, written to by the app (must be DMA-mappable). + * @rsp_size: Size of the response buffer. + * + * Sends a request to the QSEE app associated with the given ID and read back + * its response. The caller must provide two DMA memory regions, one for the + * request and one for the response, and fill out the @req region with the + * respective (app-specific) request data. The QSEE app reads this and returns + * its response in the @rsp region. + * + * Return: Zero on success, nonzero on failure. + */ +int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp, + size_t rsp_size) +{ + struct qcom_scm_qseecom_resp res = {}; + struct qcom_scm_desc desc = {}; + dma_addr_t req_phys; + dma_addr_t rsp_phys; + int status; + + /* Map request buffer */ + req_phys = dma_map_single(__scm->dev, req, req_size, DMA_TO_DEVICE); + status = dma_mapping_error(__scm->dev, req_phys); + if (status) { + dev_err(__scm->dev, "qseecom: failed to map request buffer\n"); + return status; + } + + /* Map response buffer */ + rsp_phys = dma_map_single(__scm->dev, rsp, rsp_size, DMA_FROM_DEVICE); + status = dma_mapping_error(__scm->dev, rsp_phys); + if (status) { + dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE); + dev_err(__scm->dev, "qseecom: failed to map response buffer\n"); + return status; + } + + /* Set up SCM call data */ + desc.owner = QSEECOM_TZ_OWNER_TZ_APPS; + desc.svc = QSEECOM_TZ_SVC_APP_ID_PLACEHOLDER; + desc.cmd = QSEECOM_TZ_CMD_APP_SEND; + desc.arginfo = QCOM_SCM_ARGS(5, QCOM_SCM_VAL, + QCOM_SCM_RW, QCOM_SCM_VAL, + QCOM_SCM_RW, QCOM_SCM_VAL); + desc.args[0] = app_id; + desc.args[1] = req_phys; + desc.args[2] = req_size; + desc.args[3] = rsp_phys; + desc.args[4] = rsp_size; + + /* Perform call */ + status = qcom_scm_qseecom_call(&desc, &res); + + /* Unmap buffers */ + dma_unmap_single(__scm->dev, rsp_phys, rsp_size, DMA_FROM_DEVICE); + dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE); + + if (status) + return status; + + if (res.result != QSEECOM_RESULT_SUCCESS) + return -EIO; + + return 0; +} +EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_send); + +/* + * We do not yet support re-entrant calls via the qseecom interface. To prevent + + any potential issues with this, only allow validated machines for now. + */ +static const struct of_device_id qcom_scm_qseecom_allowlist[] = { + { .compatible = "lenovo,thinkpad-x13s", }, + { } +}; + +static bool qcom_scm_qseecom_machine_is_allowed(void) +{ + struct device_node *np; + bool match; + + np = of_find_node_by_path("/"); + if (!np) + return false; + + match = of_match_node(qcom_scm_qseecom_allowlist, np); + of_node_put(np); + + return match; +} + +static void qcom_scm_qseecom_free(void *data) +{ + struct platform_device *qseecom_dev = data; + + platform_device_del(qseecom_dev); + platform_device_put(qseecom_dev); +} + +static int qcom_scm_qseecom_init(struct qcom_scm *scm) +{ + struct platform_device *qseecom_dev; + u32 version; + int ret; + + /* + * Note: We do two steps of validation here: First, we try to query the + * QSEECOM version as a check to see if the interface exists on this + * device. Second, we check against known good devices due to current + * driver limitations (see comment in qcom_scm_qseecom_allowlist). + * + * Note that we deliberately do the machine check after the version + * check so that we can log potentially supported devices. This should + * be safe as downstream sources indicate that the version query is + * neither blocking nor reentrant. + */ + ret = qcom_scm_qseecom_get_version(&version); + if (ret) + return 0; + + dev_info(scm->dev, "qseecom: found qseecom with version 0x%x\n", version); + + if (!qcom_scm_qseecom_machine_is_allowed()) { + dev_info(scm->dev, "qseecom: untested machine, skipping\n"); + return 0; + } + + /* + * Set up QSEECOM interface device. All application clients will be + * set up and managed by the corresponding driver for it. + */ + qseecom_dev = platform_device_alloc("qcom_qseecom", -1); + if (!qseecom_dev) + return -ENOMEM; + + qseecom_dev->dev.parent = scm->dev; + + ret = platform_device_add(qseecom_dev); + if (ret) { + platform_device_put(qseecom_dev); + return ret; + } + + return devm_add_action_or_reset(scm->dev, qcom_scm_qseecom_free, qseecom_dev); +} + +#else /* CONFIG_QCOM_QSEECOM */ + +static int qcom_scm_qseecom_init(struct qcom_scm *scm) +{ + return 0; +} + +#endif /* CONFIG_QCOM_QSEECOM */ + /** * qcom_scm_is_available() - Checks if SCM is available */ @@ -1468,6 +1849,19 @@ static int qcom_scm_probe(struct platform_device *pdev) if (download_mode) qcom_scm_set_download_mode(true); + /* + * Initialize the QSEECOM interface. + * + * Note: QSEECOM is fairly self-contained and this only adds the + * interface device (the driver of which does most of the heavy + * lifting). So any errors returned here should be either -ENOMEM or + * -EINVAL (with the latter only in case there's a bug in our code). + * This means that there is no need to bring down the whole SCM driver. + * Just log the error instead and let SCM live. + */ + ret = qcom_scm_qseecom_init(scm); + WARN(ret < 0, "failed to initialize qseecom: %d\n", ret); + return 0; } |