Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Sumit Garg <sumit.garg@linaro.org>
To: linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org
Cc: mark.rutland@arm.com, Sumit Garg <sumit.garg@linaro.org>,
	daniel.thompson@linaro.org, herbert@gondor.apana.org.au,
	arnd@arndb.de, ard.biesheuvel@linaro.org,
	gregkh@linuxfoundation.org, bhsharma@redhat.com,
	linux-kernel@vger.kernel.org, tee-dev@lists.linaro.org,
	robh+dt@kernel.org, mpm@selenic.com, jens.wiklander@linaro.org
Subject: [PATCH v3 1/4] tee: add bus driver framework for TEE based devices
Date: Fri, 11 Jan 2019 17:17:28 +0530
Message-ID: <1547207251-9372-2-git-send-email-sumit.garg@linaro.org> (raw)
In-Reply-To: <1547207251-9372-1-git-send-email-sumit.garg@linaro.org>

Introduce a generic TEE bus driver concept for TEE based kernel drivers
which would like to communicate with TEE based devices/services.

In this TEE bus concept, devices/services are identified via Universally
Unique Identifier (UUID) and drivers register a table of device UUIDs
which they can support.

So this TEE bus framework registers a match() callback function which
iterates over the driver UUID table to find a corresponding match for
device UUID. If a match is found, then this particular device is probed
via corresponding probe api registered by the driver. This process
happens whenever a device or a driver is registered with TEE bus.

Also this framework allows for device enumeration to be specific to
corresponding TEE implementation like OP-TEE etc.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 drivers/tee/tee_core.c  | 43 ++++++++++++++++++++++++++++++++++++++++---
 include/linux/tee_drv.h | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 7b2bb4c..a685940 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -15,7 +15,6 @@
 #define pr_fmt(fmt) "%s: " fmt, __func__
 
 #include <linux/cdev.h>
-#include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/idr.h>
 #include <linux/module.h>
@@ -1027,6 +1026,30 @@ int tee_client_invoke_func(struct tee_context *ctx,
 }
 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
 
+static int tee_client_device_match(struct device *dev,
+				   struct device_driver *drv)
+{
+	struct tee_client_device *tee_device;
+	const struct tee_client_device_id *id_table;
+
+	tee_device = to_tee_client_device(dev);
+	id_table = to_tee_client_driver(drv)->id_table;
+
+	while (!uuid_is_null(&id_table->uuid)) {
+		if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
+			return 1;
+		id_table++;
+	}
+
+	return 0;
+}
+
+struct bus_type tee_bus_type = {
+	.name		= "tee",
+	.match		= tee_client_device_match,
+};
+EXPORT_SYMBOL_GPL(tee_bus_type);
+
 static int __init tee_init(void)
 {
 	int rc;
@@ -1040,10 +1063,23 @@ static int __init tee_init(void)
 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
 	if (rc) {
 		pr_err("failed to allocate char dev region\n");
-		class_destroy(tee_class);
-		tee_class = NULL;
+		goto chrdev_err;
 	}
 
+	rc = bus_register(&tee_bus_type);
+	if (rc) {
+		pr_err("failed to register tee bus\n");
+		goto bus_err;
+	}
+
+	return 0;
+
+bus_err:
+	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
+chrdev_err:
+	class_destroy(tee_class);
+	tee_class = NULL;
+
 	return rc;
 }
 
@@ -1052,6 +1088,7 @@ static void __exit tee_exit(void)
 	class_destroy(tee_class);
 	tee_class = NULL;
 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
+	bus_unregister(&tee_bus_type);
 }
 
 subsys_initcall(tee_init);
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index 6cfe058..ed16bf1 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -20,6 +20,8 @@
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/tee.h>
+#include <linux/device.h>
+#include <linux/uuid.h>
 
 /*
  * The file describes the API provided by the generic TEE driver to the
@@ -538,4 +540,38 @@ static inline bool tee_param_is_memref(struct tee_param *param)
 	}
 }
 
+extern struct bus_type tee_bus_type;
+
+/**
+ * struct tee_client_device_id - tee based device identifier
+ * @uuid:		For TEE based client devices we use the device uuid
+ *			as the identifier.
+ */
+struct tee_client_device_id {
+	uuid_t uuid;
+};
+
+/**
+ * struct tee_client_device - tee based device
+ * @id:			device identifier
+ * @dev:		device structure
+ */
+struct tee_client_device {
+	struct tee_client_device_id id;
+	struct device dev;
+};
+#define to_tee_client_device(d) container_of(d, struct tee_client_device, dev)
+
+/**
+ * struct tee_client_driver - tee client driver
+ * @id_table:		device id table supported by this driver
+ * @driver:		driver structure
+ */
+struct tee_client_driver {
+	const struct tee_client_device_id *id_table;
+	struct device_driver driver;
+};
+#define to_tee_client_driver(d) \
+		container_of(d, struct tee_client_driver, driver)
+
 #endif /*__TEE_DRV_H*/
-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-11 11:47 [PATCH v3 0/4] Introduce TEE bus driver framework Sumit Garg
2019-01-11 11:47 ` Sumit Garg [this message]
2019-01-11 15:09   ` [PATCH v3 1/4] tee: add bus driver framework for TEE based devices Bhupesh Sharma
2019-01-15 11:53     ` Sumit Garg
2019-01-11 11:47 ` [PATCH v3 2/4] tee: add supp_nowait flag in tee_context struct Sumit Garg
2019-01-11 11:47 ` [PATCH v3 3/4] tee: optee: add TEE bus device enumeration support Sumit Garg
2019-01-11 11:47 ` [PATCH v3 4/4] hwrng: add OP-TEE based rng driver Sumit Garg

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1547207251-9372-2-git-send-email-sumit.garg@linaro.org \
    --to=sumit.garg@linaro.org \
    --cc=ard.biesheuvel@linaro.org \
    --cc=arnd@arndb.de \
    --cc=bhsharma@redhat.com \
    --cc=daniel.thompson@linaro.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=herbert@gondor.apana.org.au \
    --cc=jens.wiklander@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mpm@selenic.com \
    --cc=robh+dt@kernel.org \
    --cc=tee-dev@lists.linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org infradead-linux-arm-kernel@archiver.kernel.org
	public-inbox-index linux-arm-kernel


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox