Qualcomm TEE (QTEE) hosts Trusted Applications (TAs) and services in
the secure world, accessed via objects. A QTEE client can invoke these
objects to request services. Similarly, QTEE can request services from
the nonsecure world using objects exported to the secure world.
Add low-level primitives to facilitate the invocation of objects hosted
in QTEE, as well as those hosted in the nonsecure world.
If support for object invocation is available, the qcom_scm allocates
a dedicated child platform device. The driver for this device communicates
with QTEE using low-level primitives.
Tested-by: Neil Armstrong <neil.armstr...@linaro.org>
Tested-by: Harshal Dev <quic_h...@quicinc.com>
Signed-off-by: Amirreza Zarrabi <amirreza.zarr...@oss.qualcomm.com>
---
drivers/firmware/qcom/qcom_scm.c | 128 +++++++++++++++++++++++++++++++++
drivers/firmware/qcom/qcom_scm.h | 7 ++
include/linux/firmware/qcom/qcom_scm.h | 6 ++
3 files changed, 141 insertions(+)
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index f63b716be5b0..e3207a9d2de6 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -2087,6 +2087,124 @@ static int qcom_scm_qseecom_init(struct qcom_scm *scm)
#endif /* CONFIG_QCOM_QSEECOM */
+/**
+ * qcom_scm_qtee_invoke_smc() - Invoke a QTEE object.
+ * @inbuf: start address of memory area used for inbound buffer.
+ * @inbuf_size: size of the memory area used for inbound buffer.
+ * @outbuf: start address of memory area used for outbound buffer.
+ * @outbuf_size: size of the memory area used for outbound buffer.
+ * @result: result of QTEE object invocation.
+ * @response_type: response type returned by QTEE.
+ *
+ * @response_type determines how the contents of @inbuf and @outbuf
+ * should be processed.
+ *
+ * Return: On success, return 0 or <0 on failure.
+ */
+int qcom_scm_qtee_invoke_smc(phys_addr_t inbuf, size_t inbuf_size,
+ phys_addr_t outbuf, size_t outbuf_size,
+ u64 *result, u64 *response_type)
+{
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_SMCINVOKE,
+ .cmd = QCOM_SCM_SMCINVOKE_INVOKE,
+ .owner = ARM_SMCCC_OWNER_TRUSTED_OS,
+ .args[0] = inbuf,
+ .args[1] = inbuf_size,
+ .args[2] = outbuf,
+ .args[3] = outbuf_size,
+ .arginfo = QCOM_SCM_ARGS(4, QCOM_SCM_RW, QCOM_SCM_VAL,
+ QCOM_SCM_RW, QCOM_SCM_VAL),
+ };
+ struct qcom_scm_res res;
+ int ret;
+
+ ret = qcom_scm_call(__scm->dev, &desc, &res);
+ if (ret)
+ return ret;
+
+ *response_type = res.result[0];
+ *result = res.result[1];
+
+ return 0;
+}
+EXPORT_SYMBOL(qcom_scm_qtee_invoke_smc);
+
+/**
+ * qcom_scm_qtee_callback_response() - Submit response for callback request.
+ * @buf: start address of memory area used for outbound buffer.
+ * @buf_size: size of the memory area used for outbound buffer.
+ * @result: Result of QTEE object invocation.
+ * @response_type: Response type returned by QTEE.
+ *
+ * @response_type determines how the contents of @buf should be processed.
+ *
+ * Return: On success, return 0 or <0 on failure.
+ */
+int qcom_scm_qtee_callback_response(phys_addr_t buf, size_t buf_size,
+ u64 *result, u64 *response_type)
+{
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_SMCINVOKE,
+ .cmd = QCOM_SCM_SMCINVOKE_CB_RSP,
+ .owner = ARM_SMCCC_OWNER_TRUSTED_OS,
+ .args[0] = buf,
+ .args[1] = buf_size,
+ .arginfo = QCOM_SCM_ARGS(2, QCOM_SCM_RW, QCOM_SCM_VAL),
+ };
+ struct qcom_scm_res res;
+ int ret;
+
+ ret = qcom_scm_call(__scm->dev, &desc, &res);
+ if (ret)
+ return ret;
+
+ *response_type = res.result[0];
+ *result = res.result[1];
+
+ return 0;
+}
+EXPORT_SYMBOL(qcom_scm_qtee_callback_response);
+
+static void qcom_scm_qtee_free(void *data)
+{
+ struct platform_device *qtee_dev = data;
+
+ platform_device_unregister(qtee_dev);
+}
+
+static int qcom_scm_qtee_init(struct qcom_scm *scm)
+{
+ struct platform_device *qtee_dev;
+ u64 result, response_type;
+ int ret;
+
+ /*
+ * Check if QTEE supports smcinvoke:
+ * This will fail with -EINVAL due to invalid buffers, but first,
+ * it checks whether the call is supported in QTEE syscall handler.
+ * If not supported, -EIO is returned.
+ */
+ ret = qcom_scm_qtee_invoke_smc(0, 0, 0, 0, &result, &response_type);
+ if (ret == -EIO)
+ return -EIO;
+
+ /* Setup QTEE interface device. */
+ qtee_dev = platform_device_alloc("qcomtee", -1);
+ if (!qtee_dev)
+ return -ENOMEM;
+
+ qtee_dev->dev.parent = scm->dev;
+
+ ret = platform_device_add(qtee_dev);
+ if (ret) {
+ platform_device_put(qtee_dev);
+ return ret;
+ }
+
+ return devm_add_action_or_reset(scm->dev, qcom_scm_qtee_free, qtee_dev);
+}
+
/**
* qcom_scm_is_available() - Checks if SCM is available
*/
@@ -2322,6 +2440,16 @@ static int qcom_scm_probe(struct platform_device *pdev)
ret = qcom_scm_qseecom_init(scm);
WARN(ret < 0, "failed to initialize qseecom: %d\n", ret);
+ /*
+ * Initialize the QTEE object interface.
+ *
+ * This only represents the availability for QTEE object invocation
+ * and callback support. On failure, ignore the result. Any subsystem
+ * depending on it may fail if it tries to access this interface.
+ */
+ ret = qcom_scm_qtee_init(scm);
+ WARN(ret < 0, "failed to initialize qcomtee: %d\n", ret);
+
return 0;
err:
diff --git a/drivers/firmware/qcom/qcom_scm.h b/drivers/firmware/qcom/qcom_scm.h
index 3133d826f5fa..665e21feec9b 100644
--- a/drivers/firmware/qcom/qcom_scm.h
+++ b/drivers/firmware/qcom/qcom_scm.h
@@ -155,6 +155,13 @@ struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void);
#define QCOM_SCM_SVC_GPU 0x28
#define QCOM_SCM_SVC_GPU_INIT_REGS 0x01
+/* ARM_SMCCC_OWNER_TRUSTED_OS calls */
+
+#define QCOM_SCM_SVC_SMCINVOKE 0x06
+#define QCOM_SCM_SMCINVOKE_INVOKE_LEGACY 0x00
+#define QCOM_SCM_SMCINVOKE_CB_RSP 0x01
+#define QCOM_SCM_SMCINVOKE_INVOKE 0x02
+
/* common error codes */
#define QCOM_SCM_V2_EBUSY -12
#define QCOM_SCM_ENOMEM -5
diff --git a/include/linux/firmware/qcom/qcom_scm.h
b/include/linux/firmware/qcom/qcom_scm.h
index 983e1591bbba..b3a7cc20e617 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -176,4 +176,10 @@ static inline int qcom_scm_qseecom_app_send(u32 app_id,
#endif /* CONFIG_QCOM_QSEECOM */
+int qcom_scm_qtee_invoke_smc(phys_addr_t inbuf, size_t inbuf_size,
+ phys_addr_t outbuf, size_t outbuf_size,
+ u64 *result, u64 *response_type);
+int qcom_scm_qtee_callback_response(phys_addr_t buf, size_t buf_size,
+ u64 *result, u64 *response_type);
+
#endif
--
2.34.1
