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authorTomas Winkler <tomas.winkler@intel.com>2019-06-03 12:14:00 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-06 15:15:42 +0200
commit7e527e11d672e90f1a3dc8de84e0bfaccda15bba (patch)
treeee1893abef28b0de98f5ebb3c43aae41b877f733 /Documentation/misc-devices
parent381e9760ee87ba53df882c4affadfcc07bdf3bc2 (diff)
downloadlinux-0-day-7e527e11d672e90f1a3dc8de84e0bfaccda15bba.tar.gz
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mei: docs: move documentation under driver-api
Move mei driver documentation under Documentation/driver-api/ Perform some minimal formating changes to produce correct sphinx rendering and add index.rst Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/misc-devices')
-rw-r--r--Documentation/misc-devices/mei/mei-client-bus.txt141
-rw-r--r--Documentation/misc-devices/mei/mei.txt266
2 files changed, 0 insertions, 407 deletions
diff --git a/Documentation/misc-devices/mei/mei-client-bus.txt b/Documentation/misc-devices/mei/mei-client-bus.txt
deleted file mode 100644
index 743be4ec89899..0000000000000
--- a/Documentation/misc-devices/mei/mei-client-bus.txt
+++ /dev/null
@@ -1,141 +0,0 @@
-Intel(R) Management Engine (ME) Client bus API
-==============================================
-
-
-Rationale
-=========
-
-MEI misc character device is useful for dedicated applications to send and receive
-data to the many FW appliance found in Intel's ME from the user space.
-However for some of the ME functionalities it make sense to leverage existing software
-stack and expose them through existing kernel subsystems.
-
-In order to plug seamlessly into the kernel device driver model we add kernel virtual
-bus abstraction on top of the MEI driver. This allows implementing linux kernel drivers
-for the various MEI features as a stand alone entities found in their respective subsystem.
-Existing device drivers can even potentially be re-used by adding an MEI CL bus layer to
-the existing code.
-
-
-MEI CL bus API
-==============
-
-A driver implementation for an MEI Client is very similar to existing bus
-based device drivers. The driver registers itself as an MEI CL bus driver through
-the mei_cl_driver structure:
-
-struct mei_cl_driver {
- struct device_driver driver;
- const char *name;
-
- const struct mei_cl_device_id *id_table;
-
- int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id);
- int (*remove)(struct mei_cl_device *dev);
-};
-
-struct mei_cl_id {
- char name[MEI_NAME_SIZE];
- kernel_ulong_t driver_info;
-};
-
-The mei_cl_id structure allows the driver to bind itself against a device name.
-
-To actually register a driver on the ME Client bus one must call the mei_cl_add_driver()
-API. This is typically called at module init time.
-
-Once registered on the ME Client bus, a driver will typically try to do some I/O on
-this bus and this should be done through the mei_cl_send() and mei_cl_recv()
-routines. The latter is synchronous (blocks and sleeps until data shows up).
-In order for drivers to be notified of pending events waiting for them (e.g.
-an Rx event) they can register an event handler through the
-mei_cl_register_event_cb() routine. Currently only the MEI_EVENT_RX event
-will trigger an event handler call and the driver implementation is supposed
-to call mei_recv() from the event handler in order to fetch the pending
-received buffers.
-
-
-Example
-=======
-
-As a theoretical example let's pretend the ME comes with a "contact" NFC IP.
-The driver init and exit routines for this device would look like:
-
-#define CONTACT_DRIVER_NAME "contact"
-
-static struct mei_cl_device_id contact_mei_cl_tbl[] = {
- { CONTACT_DRIVER_NAME, },
-
- /* required last entry */
- { }
-};
-MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl);
-
-static struct mei_cl_driver contact_driver = {
- .id_table = contact_mei_tbl,
- .name = CONTACT_DRIVER_NAME,
-
- .probe = contact_probe,
- .remove = contact_remove,
-};
-
-static int contact_init(void)
-{
- int r;
-
- r = mei_cl_driver_register(&contact_driver);
- if (r) {
- pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n");
- return r;
- }
-
- return 0;
-}
-
-static void __exit contact_exit(void)
-{
- mei_cl_driver_unregister(&contact_driver);
-}
-
-module_init(contact_init);
-module_exit(contact_exit);
-
-And the driver's simplified probe routine would look like that:
-
-int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id)
-{
- struct contact_driver *contact;
-
- [...]
- mei_cl_enable_device(dev);
-
- mei_cl_register_event_cb(dev, contact_event_cb, contact);
-
- return 0;
-}
-
-In the probe routine the driver first enable the MEI device and then registers
-an ME bus event handler which is as close as it can get to registering a
-threaded IRQ handler.
-The handler implementation will typically call some I/O routine depending on
-the pending events:
-
-#define MAX_NFC_PAYLOAD 128
-
-static void contact_event_cb(struct mei_cl_device *dev, u32 events,
- void *context)
-{
- struct contact_driver *contact = context;
-
- if (events & BIT(MEI_EVENT_RX)) {
- u8 payload[MAX_NFC_PAYLOAD];
- int payload_size;
-
- payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD);
- if (payload_size <= 0)
- return;
-
- /* Hook to the NFC subsystem */
- nfc_hci_recv_frame(contact->hdev, payload, payload_size);
- }
-}
diff --git a/Documentation/misc-devices/mei/mei.txt b/Documentation/misc-devices/mei/mei.txt
deleted file mode 100644
index 2b80a0cd621f0..0000000000000
--- a/Documentation/misc-devices/mei/mei.txt
+++ /dev/null
@@ -1,266 +0,0 @@
-Intel(R) Management Engine Interface (Intel(R) MEI)
-===================================================
-
-Introduction
-============
-
-The Intel Management Engine (Intel ME) is an isolated and protected computing
-resource (Co-processor) residing inside certain Intel chipsets. The Intel ME
-provides support for computer/IT management features. The feature set
-depends on the Intel chipset SKU.
-
-The Intel Management Engine Interface (Intel MEI, previously known as HECI)
-is the interface between the Host and Intel ME. This interface is exposed
-to the host as a PCI device. The Intel MEI Driver is in charge of the
-communication channel between a host application and the Intel ME feature.
-
-Each Intel ME feature (Intel ME Client) is addressed by a GUID/UUID and
-each client has its own protocol. The protocol is message-based with a
-header and payload up to 512 bytes.
-
-Prominent usage of the Intel ME Interface is to communicate with Intel(R)
-Active Management Technology (Intel AMT) implemented in firmware running on
-the Intel ME.
-
-Intel AMT provides the ability to manage a host remotely out-of-band (OOB)
-even when the operating system running on the host processor has crashed or
-is in a sleep state.
-
-Some examples of Intel AMT usage are:
- - Monitoring hardware state and platform components
- - Remote power off/on (useful for green computing or overnight IT
- maintenance)
- - OS updates
- - Storage of useful platform information such as software assets
- - Built-in hardware KVM
- - Selective network isolation of Ethernet and IP protocol flows based
- on policies set by a remote management console
- - IDE device redirection from remote management console
-
-Intel AMT (OOB) communication is based on SOAP (deprecated
-starting with Release 6.0) over HTTP/S or WS-Management protocol over
-HTTP/S that are received from a remote management console application.
-
-For more information about Intel AMT:
-http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide
-
-
-Intel MEI Driver
-================
-
-The driver exposes a misc device called /dev/mei.
-
-An application maintains communication with an Intel ME feature while
-/dev/mei is open. The binding to a specific feature is performed by calling
-MEI_CONNECT_CLIENT_IOCTL, which passes the desired UUID.
-The number of instances of an Intel ME feature that can be opened
-at the same time depends on the Intel ME feature, but most of the
-features allow only a single instance.
-
-The Intel AMT Host Interface (Intel AMTHI) feature supports multiple
-simultaneous user connected applications. The Intel MEI driver
-handles this internally by maintaining request queues for the applications.
-
-The driver is transparent to data that are passed between firmware feature
-and host application.
-
-Because some of the Intel ME features can change the system
-configuration, the driver by default allows only a privileged
-user to access it.
-
-A code snippet for an application communicating with Intel AMTHI client:
-
- struct mei_connect_client_data data;
- fd = open(MEI_DEVICE);
-
- data.d.in_client_uuid = AMTHI_UUID;
-
- ioctl(fd, IOCTL_MEI_CONNECT_CLIENT, &data);
-
- printf("Ver=%d, MaxLen=%ld\n",
- data.d.in_client_uuid.protocol_version,
- data.d.in_client_uuid.max_msg_length);
-
- [...]
-
- write(fd, amthi_req_data, amthi_req_data_len);
-
- [...]
-
- read(fd, &amthi_res_data, amthi_res_data_len);
-
- [...]
- close(fd);
-
-
-IOCTL
-=====
-
-The Intel MEI Driver supports the following IOCTL commands:
- IOCTL_MEI_CONNECT_CLIENT Connect to firmware Feature (client).
-
- usage:
- struct mei_connect_client_data clientData;
- ioctl(fd, IOCTL_MEI_CONNECT_CLIENT, &clientData);
-
- inputs:
- mei_connect_client_data struct contain the following
- input field:
-
- in_client_uuid - UUID of the FW Feature that needs
- to connect to.
- outputs:
- out_client_properties - Client Properties: MTU and Protocol Version.
-
- error returns:
- EINVAL Wrong IOCTL Number
- ENODEV Device or Connection is not initialized or ready.
- (e.g. Wrong UUID)
- ENOMEM Unable to allocate memory to client internal data.
- EFAULT Fatal Error (e.g. Unable to access user input data)
- EBUSY Connection Already Open
-
- Notes:
- max_msg_length (MTU) in client properties describes the maximum
- data that can be sent or received. (e.g. if MTU=2K, can send
- requests up to bytes 2k and received responses up to 2k bytes).
-
- IOCTL_MEI_NOTIFY_SET: enable or disable event notifications
-
- Usage:
- uint32_t enable;
- ioctl(fd, IOCTL_MEI_NOTIFY_SET, &enable);
-
- Inputs:
- uint32_t enable = 1;
- or
- uint32_t enable[disable] = 0;
-
- Error returns:
- EINVAL Wrong IOCTL Number
- ENODEV Device is not initialized or the client not connected
- ENOMEM Unable to allocate memory to client internal data.
- EFAULT Fatal Error (e.g. Unable to access user input data)
- EOPNOTSUPP if the device doesn't support the feature
-
- Notes:
- The client must be connected in order to enable notification events
-
-
- IOCTL_MEI_NOTIFY_GET : retrieve event
-
- Usage:
- uint32_t event;
- ioctl(fd, IOCTL_MEI_NOTIFY_GET, &event);
-
- Outputs:
- 1 - if an event is pending
- 0 - if there is no even pending
-
- Error returns:
- EINVAL Wrong IOCTL Number
- ENODEV Device is not initialized or the client not connected
- ENOMEM Unable to allocate memory to client internal data.
- EFAULT Fatal Error (e.g. Unable to access user input data)
- EOPNOTSUPP if the device doesn't support the feature
-
- Notes:
- The client must be connected and event notification has to be enabled
- in order to receive an event
-
-
-Intel ME Applications
-=====================
-
- 1) Intel Local Management Service (Intel LMS)
-
- Applications running locally on the platform communicate with Intel AMT Release
- 2.0 and later releases in the same way that network applications do via SOAP
- over HTTP (deprecated starting with Release 6.0) or with WS-Management over
- SOAP over HTTP. This means that some Intel AMT features can be accessed from a
- local application using the same network interface as a remote application
- communicating with Intel AMT over the network.
-
- When a local application sends a message addressed to the local Intel AMT host
- name, the Intel LMS, which listens for traffic directed to the host name,
- intercepts the message and routes it to the Intel MEI.
- For more information:
- http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide
- Under "About Intel AMT" => "Local Access"
-
- For downloading Intel LMS:
- http://software.intel.com/en-us/articles/download-the-latest-intel-amt-open-source-drivers/
-
- The Intel LMS opens a connection using the Intel MEI driver to the Intel LMS
- firmware feature using a defined UUID and then communicates with the feature
- using a protocol called Intel AMT Port Forwarding Protocol (Intel APF protocol).
- The protocol is used to maintain multiple sessions with Intel AMT from a
- single application.
-
- See the protocol specification in the Intel AMT Software Development Kit (SDK)
- http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide
- Under "SDK Resources" => "Intel(R) vPro(TM) Gateway (MPS)"
- => "Information for Intel(R) vPro(TM) Gateway Developers"
- => "Description of the Intel AMT Port Forwarding (APF) Protocol"
-
- 2) Intel AMT Remote configuration using a Local Agent
-
- A Local Agent enables IT personnel to configure Intel AMT out-of-the-box
- without requiring installing additional data to enable setup. The remote
- configuration process may involve an ISV-developed remote configuration
- agent that runs on the host.
- For more information:
- http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide
- Under "Setup and Configuration of Intel AMT" =>
- "SDK Tools Supporting Setup and Configuration" =>
- "Using the Local Agent Sample"
-
- An open source Intel AMT configuration utility, implementing a local agent
- that accesses the Intel MEI driver, can be found here:
- http://software.intel.com/en-us/articles/download-the-latest-intel-amt-open-source-drivers/
-
-
-Intel AMT OS Health Watchdog
-============================
-
-The Intel AMT Watchdog is an OS Health (Hang/Crash) watchdog.
-Whenever the OS hangs or crashes, Intel AMT will send an event
-to any subscriber to this event. This mechanism means that
-IT knows when a platform crashes even when there is a hard failure on the host.
-
-The Intel AMT Watchdog is composed of two parts:
- 1) Firmware feature - receives the heartbeats
- and sends an event when the heartbeats stop.
- 2) Intel MEI iAMT watchdog driver - connects to the watchdog feature,
- configures the watchdog and sends the heartbeats.
-
-The Intel iAMT watchdog MEI driver uses the kernel watchdog API to configure
-the Intel AMT Watchdog and to send heartbeats to it. The default timeout of the
-watchdog is 120 seconds.
-
-If the Intel AMT is not enabled in the firmware then the watchdog client won't enumerate
-on the me client bus and watchdog devices won't be exposed.
-
-
-Supported Chipsets
-==================
-
-7 Series Chipset Family
-6 Series Chipset Family
-5 Series Chipset Family
-4 Series Chipset Family
-Mobile 4 Series Chipset Family
-ICH9
-82946GZ/GL
-82G35 Express
-82Q963/Q965
-82P965/G965
-Mobile PM965/GM965
-Mobile GME965/GLE960
-82Q35 Express
-82G33/G31/P35/P31 Express
-82Q33 Express
-82X38/X48 Express
-
----
-linux-mei@linux.intel.com