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

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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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
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:
docs: ABI: testing: make the files compatible with ReST output Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-30 08:40:39 +01:00
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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
- "single", for contiguous buffer mode (high-order alloc);
- "multi", for multiblock mode;
- "ExI", for DCI handler mode;
intel_th: msu: Introduce buffer interface Introduces a concept of external buffers, which is a mechanism for creating trace sinks that would receive trace data from MSC buffers and transfer it elsewhere. A external buffer can implement its own window allocation/deallocation if it has to. It must provide a callback that's used to notify it when a window fills up, so that it can then start a DMA transaction from that window 'elsewhere'. This window remains in a 'locked' state and won't be used for storing new trace data until the buffer 'unlocks' it with a provided API call, at which point the window can be used again for storing trace data. This relies on a functional "last block" interrupt, so not all versions of Trace Hub can use this feature, which does not reflect on existing users. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20190705141425.19894-2-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-05 17:14:21 +03:00
- "debug", for debug mode;
- any of the currently loaded buffer sinks.
docs: ABI: testing: make the files compatible with ReST output Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-30 08:40:39 +01:00
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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
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.
docs: ABI: testing: make the files compatible with ReST output Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-30 08:40:39 +01:00
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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
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.
docs: ABI: testing: make the files compatible with ReST output Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-30 08:40:39 +01:00
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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
Writing to this file deallocates existing buffer (provided
there are no active users and tracing is not enabled) and then
allocates a new one.
intel_th: msu: Add a sysfs attribute to trigger window switch Now that we have the means to trigger a window switch for the MSU trace store, add a sysfs file to allow triggering it from userspace. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03 11:44:50 +03:00
What: /sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/win_switch
Date: May 2019
KernelVersion: 5.2
Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Description: (RW) Trigger window switch for the MSC's buffer, in
multi-window mode. In "multi" mode, accepts writes of "1", thereby
triggering a window switch for the buffer. Returns an error in any
other operating mode or attempts to write something other than "1".
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: Laurent Fert <laurent.fert@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-22 15:47:18 +03:00
intel_th: msu: Make stopping the trace optional Some use cases prefer to keep collecting the trace data into the last available window while the other windows are being offloaded instead of stopping the trace. In this scenario, the window switch happens automatically when the next window becomes available again. Add an option to allow this and a sysfs attribute to enable it. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20200319085152.52183-1-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19 10:51:52 +02:00
What: /sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/stop_on_full
Date: March 2020
KernelVersion: 5.7
Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Description: (RW) Configure whether trace stops when the last available window
becomes full (1/y/Y) or wraps around and continues until the next
window becomes available again (0/n/N).
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