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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2015-09-22 15:47:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-04 22:28:58 +0300 |
| commit | ba82664c134ef7ab97808f09a3c5e894b0a4900d (patch) | |
| tree | ba2e8cb6cd816dd2ec05a678c3c9b3688d73d66f /Documentation | |
| parent | f04e449fc76e7bfd1b8ed11967ab092d05355b6b (diff) | |
| download | linux-ba82664c134ef7ab97808f09a3c5e894b0a4900d.tar.xz | |
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>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc new file mode 100644 index 000000000000..b940c5d91cf7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc @@ -0,0 +1,33 @@ +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. + + |