fastrpc: move ADSP duplicate session management to the driver

Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml

@@ -89,8 +89,10 @@ patternProperties:
       qcom,nsessions:
         $ref: /schemas/types.yaml#/definitions/uint32
         default: 1
+        deprecated: true
         description: >
           A value indicating how many sessions can share this context bank.
+          Session duplication is now handled by the driver.
 
     required:
       - compatible

drivers/misc/fastrpc.c

@@ -33,6 +33,7 @@
 #define CDSP_DOMAIN_ID (3)
 #define GDSP_DOMAIN_ID (4)
 #define FASTRPC_MAX_SESSIONS	14
+#define FASTRPC_DUP_SESSIONS	4
 #define FASTRPC_MAX_VMIDS	16
 #define FASTRPC_ALIGN		128
 #define FASTRPC_MAX_FDLIST	16
@@ -2395,48 +2396,37 @@ static const struct file_operations fastrpc_fops = {
 	.compat_ioctl = fastrpc_device_ioctl,
 };
 
-static int fastrpc_cb_probe(struct platform_device *pdev)
+static int fastrpc_cb_init(struct platform_device *pdev)
 {
 	struct fastrpc_channel_ctx *cctx;
 	struct fastrpc_session_ctx *sess;
 	struct device *dev = &pdev->dev;
-	int i, sessions = 0;
 	unsigned long flags;
+	u32 sid = 0;
 	int rc;
 
 	cctx = dev_get_drvdata(dev->parent);
 	if (!cctx)
 		return -EINVAL;
 
-	of_property_read_u32(dev->of_node, "qcom,nsessions", &sessions);
+	if (of_property_read_u32(dev->of_node, "reg", &sid))
+		dev_info(dev, "FastRPC Session ID not specified in DT\n");
 
 	spin_lock_irqsave(&cctx->lock, flags);
 	if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) {
-		dev_err(&pdev->dev, "too many sessions\n");
 		spin_unlock_irqrestore(&cctx->lock, flags);
+		dev_err(dev, "too many sessions\n");
 		return -ENOSPC;
 	}
 	sess = &cctx->session[cctx->sesscount++];
 	sess->used = false;
 	sess->valid = true;
 	sess->dev = dev;
+	sess->sid = sid;
 	sess->coherent = of_property_read_bool(dev->of_node, "dma-coherent");
 	dev_set_drvdata(dev, sess);
-
-	if (of_property_read_u32(dev->of_node, "reg", &sess->sid))
-		dev_info(dev, "FastRPC Session ID not specified in DT\n");
-
-	if (sessions > 0) {
-		struct fastrpc_session_ctx *dup_sess;
-
-		for (i = 1; i < sessions; i++) {
-			if (cctx->sesscount >= FASTRPC_MAX_SESSIONS)
-				break;
-			dup_sess = &cctx->session[cctx->sesscount++];
-			memcpy(dup_sess, sess, sizeof(*dup_sess));
-		}
-	}
 	spin_unlock_irqrestore(&cctx->lock, flags);
+
 	rc = dma_set_mask(dev, DMA_BIT_MASK(32));
 	if (rc) {
 		dev_err(dev, "32-bit DMA enable failed\n");
@@ -2446,37 +2436,63 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static void fastrpc_cb_remove(struct platform_device *pdev)
+static void fastrpc_cb_devices_destroy(struct rpmsg_device *rpdev)
 {
-	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(pdev->dev.parent);
-	struct fastrpc_session_ctx *sess = dev_get_drvdata(&pdev->dev);
+	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
+	struct device *rdev = &rpdev->dev;
+	struct platform_device *pdev;
+	struct device_node *np;
 	unsigned long flags;
 	int i;
 
 	spin_lock_irqsave(&cctx->lock, flags);
-	for (i = 0; i < FASTRPC_MAX_SESSIONS; i++) {
-		if (cctx->session[i].sid == sess->sid) {
-			cctx->session[i].valid = false;
-			cctx->sesscount--;
+	for (i = 0; i < cctx->sesscount; i++)
+		cctx->session[i].valid = false;
+	spin_unlock_irqrestore(&cctx->lock, flags);
+
+	for_each_available_child_of_node(rdev->of_node, np) {
+		if (!of_device_is_compatible(np, "qcom,fastrpc-compute-cb")) {
+			of_node_put(np);
+			continue;
 		}
+
+		pdev = of_find_device_by_node(np);
+		of_node_put(np);
+		if (pdev)
+			of_platform_device_destroy(&pdev->dev, NULL);
 	}
-	spin_unlock_irqrestore(&cctx->lock, flags);
 }
 
-static const struct of_device_id fastrpc_match_table[] = {
-	{ .compatible = "qcom,fastrpc-compute-cb", },
-	{}
-};
+static int fastrpc_cb_devices_create(struct rpmsg_device *rpdev)
+{
+	struct device *rdev = &rpdev->dev;
+	struct platform_device *pdev;
+	struct device_node *np;
+	int err;
 
-static struct platform_driver fastrpc_cb_driver = {
-	.probe = fastrpc_cb_probe,
-	.remove = fastrpc_cb_remove,
-	.driver = {
-		.name = "qcom,fastrpc-cb",
-		.of_match_table = fastrpc_match_table,
-		.suppress_bind_attrs = true,
-	},
-};
+	for_each_available_child_of_node(rdev->of_node, np) {
+		if (!of_device_is_compatible(np, "qcom,fastrpc-compute-cb")) {
+			of_node_put(np);
+			continue;
+		}
+
+		pdev = of_platform_device_create(np, NULL, rdev);
+		if (!pdev) {
+			of_node_put(np);
+			fastrpc_cb_devices_destroy(rpdev);
+			return -EINVAL;
+		}
+
+		err = fastrpc_cb_init(pdev);
+		if (err) {
+			of_node_put(np);
+			fastrpc_cb_devices_destroy(rpdev);
+			return err;
+		}
+	}
+
+	return 0;
+}
 
 static int fastrpc_device_register(struct device *dev, struct fastrpc_channel_ctx *cctx,
 				   bool is_secured, const char *domain)
@@ -2731,10 +2747,26 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 	data->rpdev = rpdev;
 	dev_set_drvdata(&rpdev->dev, data);
 
-	err = of_platform_populate(rdev->of_node, NULL, NULL, rdev);
+	err = fastrpc_cb_devices_create(rpdev);
 	if (err)
 		goto err_deregister_fdev;
 
+	if (data->domain_id == ADSP_DOMAIN_ID && data->sesscount > 0) {
+		struct fastrpc_session_ctx *last_sess;
+		struct fastrpc_session_ctx *dup_sess;
+		unsigned long flags;
+
+		spin_lock_irqsave(&data->lock, flags);
+		last_sess = &data->session[data->sesscount - 1];
+		for (i = 0; i < FASTRPC_DUP_SESSIONS; i++) {
+			if (data->sesscount >= FASTRPC_MAX_SESSIONS)
+				break;
+			dup_sess = &data->session[data->sesscount++];
+			memcpy(dup_sess, last_sess, sizeof(*dup_sess));
+		}
+		spin_unlock_irqrestore(&data->lock, flags);
+	}
+
 	return 0;
 
 err_deregister_fdev:
@@ -2810,7 +2842,7 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 		}
 	}
 
-	of_platform_depopulate(&rpdev->dev);
+	fastrpc_cb_devices_destroy(rpdev);
 
 	fastrpc_channel_ctx_put(cctx);
 }
@@ -2871,33 +2903,7 @@ static struct rpmsg_driver fastrpc_driver = {
 	},
 };
 
-static int fastrpc_init(void)
-{
-	int ret;
-
-	ret = platform_driver_register(&fastrpc_cb_driver);
-	if (ret < 0) {
-		pr_err("fastrpc: failed to register cb driver\n");
-		return ret;
-	}
-
-	ret = register_rpmsg_driver(&fastrpc_driver);
-	if (ret < 0) {
-		pr_err("fastrpc: failed to register rpmsg driver\n");
-		platform_driver_unregister(&fastrpc_cb_driver);
-		return ret;
-	}
-
-	return 0;
-}
-module_init(fastrpc_init);
-
-static void fastrpc_exit(void)
-{
-	platform_driver_unregister(&fastrpc_cb_driver);
-	unregister_rpmsg_driver(&fastrpc_driver);
-}
-module_exit(fastrpc_exit);
+module_rpmsg_driver(fastrpc_driver);
 
 MODULE_DESCRIPTION("Qualcomm FastRPC");
 MODULE_LICENSE("GPL v2");