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| author |   Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-05-03 11:44:50 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-03 18:17:40 +0200 |
| commit | 6cac7866c27418cd784fbb8041c2dddd6d966bc7 (patch) | |
| tree | 1d6470e54a77ac654b05728552953a8317413c6e | |
| parent | intel_th: msu: Correct the block wrap detection (diff) | |
| download | linux-dev-6cac7866c27418cd784fbb8041c2dddd6d966bc7.tar.xz linux-dev-6cac7866c27418cd784fbb8041c2dddd6d966bc7.zip | |
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>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc | 8 | ||||
| -rw-r--r-- | drivers/hwtracing/intel_th/msu.c | 28 |
2 files changed, 36 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 index b940c5d91cf7..f54ae244f3f1 100644 --- a/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc +++ b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc @@ -30,4 +30,12 @@ Description: (RW) Configure MSC buffer size for "single" or "multi" modes. there are no active users and tracing is not enabled) and then allocates a new one. +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". diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index b0bb69942328..aed72b33675d 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -1572,10 +1572,38 @@ free_win: static DEVICE_ATTR_RW(nr_pages); +static ssize_t +win_switch_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + struct msc *msc = dev_get_drvdata(dev); + unsigned long val; + int ret; + + ret = kstrtoul(buf, 10, &val); + if (ret) + return ret; + + if (val != 1) + return -EINVAL; + + mutex_lock(&msc->buf_mutex); + if (msc->mode != MSC_MODE_MULTI) + ret = -ENOTSUPP; + else + ret = intel_th_trace_switch(msc->thdev); + mutex_unlock(&msc->buf_mutex); + + return ret ? ret : size; +} + +static DEVICE_ATTR_WO(win_switch); + static struct attribute *msc_output_attrs[] = { &dev_attr_wrap.attr, &dev_attr_mode.attr, &dev_attr_nr_pages.attr, + &dev_attr_win_switch.attr, NULL, }; |