linux/Documentation/ABI/testing/sysfs-class-mic.txt
Dasaratharaman Chandramouli af190494f9 misc: mic: Enable OSPM suspend and resume support.
This patch enables support for OSPM suspend and resume in the MIC
driver. During a host suspend event, the driver performs an
orderly shutdown of the cards if they are online. Upon resume, any
cards that were previously online before suspend are rebooted.
The driver performs an orderly shutdown of the card primarily to
ensure that applications in the card are terminated and mounted
devices are safely un-mounted before the card is powered down in
the event of an OSPM suspend.

The driver makes use of the MIC daemon to accomplish OSPM suspend
and resume. The driver registers a PM notifier per MIC device.
The devices get notified synchronously during PM_SUSPEND_PREPARE and
PM_POST_SUSPEND phases.

During the PM_SUSPEND_PREPARE phase, the driver performs one of the
following three tasks.
1) If the card is 'offline', the driver sets the card to a
   'suspended' state and returns.
2) If the card is 'online', the driver initiates card shutdown by
   setting the card state to suspending. This notifies the MIC
   daemon which invokes shutdown and sets card state to 'suspended'.
   The driver returns after the shutdown is complete.
3) If the card is already being shutdown, possibly by a host user
   space application, the driver sets the card state to 'suspended'
   and returns after the shutdown is complete.

During the PM_POST_SUSPEND phase, the driver simply notifies the
daemon and returns. The daemon boots those cards that were previously
online during the suspend phase.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Harshavardhan R Kharche <harshavardhan.r.kharche@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05 18:01:42 -07:00

158 lines
6.1 KiB
Plaintext

What: /sys/class/mic/
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
The mic class directory belongs to Intel MIC devices and
provides information per MIC device. An Intel MIC device is a
PCIe form factor add-in Coprocessor card based on the Intel Many
Integrated Core (MIC) architecture that runs a Linux OS.
What: /sys/class/mic/mic(x)
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
The directories /sys/class/mic/mic0, /sys/class/mic/mic1 etc.,
represent MIC devices (0,1,..etc). Each directory has
information specific to that MIC device.
What: /sys/class/mic/mic(x)/family
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
Provides information about the Coprocessor family for an Intel
MIC device. For example - "x100"
What: /sys/class/mic/mic(x)/stepping
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
Provides information about the silicon stepping for an Intel
MIC device. For example - "A0" or "B0"
What: /sys/class/mic/mic(x)/state
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
When read, this entry provides the current state of an Intel
MIC device in the context of the card OS. Possible values that
will be read are:
"offline" - The MIC device is ready to boot the card OS. On
reading this entry after an OSPM resume, a "boot" has to be
written to this entry if the card was previously shutdown
during OSPM suspend.
"online" - The MIC device has initiated booting a card OS.
"shutting_down" - The card OS is shutting down.
"reset_failed" - The MIC device has failed to reset.
"suspending" - The MIC device is currently being prepared for
suspend. On reading this entry, a "suspend" has to be written
to the state sysfs entry to ensure the card is shutdown during
OSPM suspend.
"suspended" - The MIC device has been suspended.
When written, this sysfs entry triggers different state change
operations depending upon the current state of the card OS.
Acceptable values are:
"boot" - Boot the card OS image specified by the combination
of firmware, ramdisk, cmdline and bootmode
sysfs entries.
"reset" - Initiates device reset.
"shutdown" - Initiates card OS shutdown.
"suspend" - Initiates card OS shutdown and also marks the card
as suspended.
What: /sys/class/mic/mic(x)/shutdown_status
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
An Intel MIC device runs a Linux OS during its operation. This
OS can shutdown because of various reasons. When read, this
entry provides the status on why the card OS was shutdown.
Possible values are:
"nop" - shutdown status is not applicable, when the card OS is
"online"
"crashed" - Shutdown because of a HW or SW crash.
"halted" - Shutdown because of a halt command.
"poweroff" - Shutdown because of a poweroff command.
"restart" - Shutdown because of a restart command.
What: /sys/class/mic/mic(x)/cmdline
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
An Intel MIC device runs a Linux OS during its operation. Before
booting this card OS, it is possible to pass kernel command line
options to configure various features in it, similar to
self-bootable machines. When read, this entry provides
information about the current kernel command line options set to
boot the card OS. This entry can be written to change the
existing kernel command line options. Typically, the user would
want to read the current command line options, append new ones
or modify existing ones and then write the whole kernel command
line back to this entry.
What: /sys/class/mic/mic(x)/firmware
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
When read, this sysfs entry provides the path name under
/lib/firmware/ where the firmware image to be booted on the
card can be found. The entry can be written to change the
firmware image location under /lib/firmware/.
What: /sys/class/mic/mic(x)/ramdisk
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
When read, this sysfs entry provides the path name under
/lib/firmware/ where the ramdisk image to be used during card
OS boot can be found. The entry can be written to change
the ramdisk image location under /lib/firmware/.
What: /sys/class/mic/mic(x)/bootmode
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
When read, this sysfs entry provides the current bootmode for
the card. This sysfs entry can be written with the following
valid strings:
a) linux - Boot a Linux image.
b) elf - Boot an elf image for flash updates.
What: /sys/class/mic/mic(x)/log_buf_addr
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
An Intel MIC device runs a Linux OS during its operation. For
debugging purpose and early kernel boot messages, the user can
access the card OS log buffer via debugfs. When read, this entry
provides the kernel virtual address of the buffer where the card
OS log buffer can be read. This entry is written by the host
configuration daemon to set the log buffer address. The correct
log buffer address to be written can be found in the System.map
file of the card OS.
What: /sys/class/mic/mic(x)/log_buf_len
Date: October 2013
KernelVersion: 3.13
Contact: Sudeep Dutt <sudeep.dutt@intel.com>
Description:
An Intel MIC device runs a Linux OS during its operation. For
debugging purpose and early kernel boot messages, the user can
access the card OS log buffer via debugfs. When read, this entry
provides the kernel virtual address where the card OS log buffer
length can be read. This entry is written by host configuration
daemon to set the log buffer length address. The correct log
buffer length address to be written can be found in the
System.map file of the card OS.