firmware: qcom: scm: add support for object invocation

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.armstrong@linaro.org>
Tested-by: Harshal Dev <quic_hdev@quicinc.com>
Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250911-qcom-tee-using-tee-ss-without-mem-obj-v12-2-17f07a942b8d@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 26cd0458aacd67dcd36f065675e969cea97eb465..9b5a9a0f68cfae958ae42fbf6f93cb93c5925174 100644 (file)
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -2093,6 +2093,122 @@ 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;
+
+       if (response_type)
+               *response_type = res.result[0];
+
+       if (result)
+               *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;
+
+       if (response_type)
+               *response_type = res.result[0];
+
+       if (result)
+               *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 void qcom_scm_qtee_init(struct qcom_scm *scm)
+{
+       struct platform_device *qtee_dev;
+       u64 result, response_type;
+       int ret;
+
+       /*
+        * Probe for smcinvoke support. This will fail due to invalid buffers,
+        * but first, it checks whether the call is supported in QTEE syscall
+        * handler. If it is not supported, -EIO is returned.
+        */
+       ret = qcom_scm_qtee_invoke_smc(0, 0, 0, 0, &result, &response_type);
+       if (ret == -EIO)
+               return;
+
+       /* Setup QTEE interface device. */
+       qtee_dev = platform_device_register_data(scm->dev, "qcomtee",
+                                                PLATFORM_DEVID_NONE, NULL, 0);
+       if (IS_ERR(qtee_dev))
+               return;
+
+       devm_add_action_or_reset(scm->dev, qcom_scm_qtee_free, qtee_dev);
+}
+
 /**
  * qcom_scm_is_available() - Checks if SCM is available
  */
@@ -2325,6 +2441,9 @@ 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. */
+       qcom_scm_qtee_init(scm);
+
        return 0;
 }
 

diff --git a/drivers/firmware/qcom/qcom_scm.h b/drivers/firmware/qcom/qcom_scm.h
index 0e8dd838099e1176b6d6bf76a204c875698eb1f7..a56c8212cc0c41021e5a067d52b7d5dcc49107ea 100644 (file)
--- a/drivers/firmware/qcom/qcom_scm.h
+++ b/drivers/firmware/qcom/qcom_scm.h
@@ -156,6 +156,13 @@ int qcom_scm_shm_bridge_enable(struct device *scm_dev);
 #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 0f667bf1d4d9d8c3e63d69159e3cdec2fb40396b..a55ca771286bfe7fe8df38ef08225901aa71ad63 100644 (file)
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -175,4 +175,10 @@ 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