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Commit ba82664c authored by Alexander Shishkin's avatar Alexander Shishkin Committed by Greg Kroah-Hartman
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intel_th: Add Memory Storage Unit driver 



Memory Storage Unit (MSU) is a trace output device that collects trace
data to system memory. It consists of 2 independent Memory Storage
Controllers (MSCs).

This driver provides userspace interfaces to configure in-memory tracing
parameters, such as contiguous (high-order allocation) buffer or multiblock
(scatter list) buffer mode, wrapping (data overwrite) and number and sizes
of windows in multiblock mode. Userspace can read the buffers via mmap()ing
or read()ing of the corresponding device node.

Signed-off-by: default avatarLaurent Fert <laurent.fert@intel.com>
Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f04e449f

Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc

0 → 100644
+33 −0
Original line number Diff line number Diff line 
What:		/sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/wrap

Date:		June 2015

KernelVersion:	4.3

Contact:	Alexander Shishkin <alexander.shishkin@linux.intel.com>

Description:	(RW) Configure MSC buffer wrapping. 1 == wrapping enabled.



What:		/sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/mode

Date:		June 2015

KernelVersion:	4.3

Contact:	Alexander Shishkin <alexander.shishkin@linux.intel.com>

Description:	(RW) Configure MSC operating mode:

		  - "single", for contiguous buffer mode (high-order alloc);

		  - "multi", for multiblock mode;

		  - "ExI", for DCI handler mode;

		  - "debug", for debug mode.

		If operating mode changes, existing buffer is deallocated,

		provided there are no active users and tracing is not enabled,

		otherwise the write will fail.



What:		/sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/nr_pages

Date:		June 2015

KernelVersion:	4.3

Contact:	Alexander Shishkin <alexander.shishkin@linux.intel.com>

Description:	(RW) Configure MSC buffer size for "single" or "multi" modes.

		In single mode, this is a single number of pages, has to be

		power of 2. In multiblock mode, this is a comma-separated list

		of numbers of pages for each window to be allocated. Number of

		windows is not limited.

		Writing to this file deallocates existing buffer (provided

		there are no active users and tracing is not enabled) and then

		allocates a new one.

drivers/hwtracing/intel_th/Kconfig

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@@ -44,6 +44,16 @@ config INTEL_TH_STH 


	  Say Y here to enable STH subdevice of Intel(R) Trace Hub.



config INTEL_TH_MSU

	tristate "Intel(R) Trace Hub Memory Storage Unit"

	help

	  Memory Storage Unit (MSU) trace output device enables

	  storing STP traces to system memory. It supports single

	  and multiblock modes of operation and provides read()

	  and mmap() access to the collected data.



	  Say Y here to enable MSU output device for Intel TH.



config INTEL_TH_DEBUG

	bool "Intel(R) Trace Hub debugging"

	depends on DEBUG_FS

drivers/hwtracing/intel_th/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -10,3 +10,6 @@ intel_th_gth-y := gth.o 


obj-$(CONFIG_INTEL_TH_STH)	+= intel_th_sth.o

intel_th_sth-y			:= sth.o



obj-$(CONFIG_INTEL_TH_MSU)	+= intel_th_msu.o

intel_th_msu-y			:= msu.o