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([10.237.72.28]) by orsmga008.jf.intel.com with ESMTP; 19 Mar 2020 01:51:57 -0700 From: Alexander Shishkin To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, Alexander Shishkin , Andy Shevchenko Subject: [PATCH v1] intel_th: msu: Make stopping the trace optional Date: Thu, 19 Mar 2020 10:51:52 +0200 Message-Id: <20200319085152.52183-1-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200318102615.GC2126918@kroah.com> References: <20200318102615.GC2126918@kroah.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Reviewed-by: Andy Shevchenko --- .../testing/sysfs-bus-intel_th-devices-msc | 8 ++++ drivers/hwtracing/intel_th/msu.c | 38 ++++++++++++++++++- 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc index 456cb62b384c..7fd2601c2831 100644 --- a/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc +++ b/Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc @@ -40,3 +40,11 @@ Description: (RW) Trigger window switch for the MSC's buffer, in triggering a window switch for the buffer. Returns an error in any other operating mode or attempts to write something other than "1". +What: /sys/bus/intel_th/devices/-msc/stop_on_full +Date: March 2020 +KernelVersion: 5.7 +Contact: Alexander Shishkin +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). + diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index 6e118b790d83..db04086122dc 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -138,6 +138,7 @@ struct msc { struct list_head win_list; struct sg_table single_sgt; struct msc_window *cur_win; + struct msc_window *switch_on_unlock; unsigned long nr_pages; unsigned long single_sz; unsigned int single_wrap : 1; @@ -154,6 +155,8 @@ struct msc { struct list_head iter_list; + bool stop_on_full; + /* config */ unsigned int enabled : 1, wrap : 1, @@ -1717,6 +1720,10 @@ void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt) return; msc_win_set_lockout(win, WIN_LOCKED, WIN_READY); + if (msc->switch_on_unlock == win) { + msc->switch_on_unlock = NULL; + msc_win_switch(msc); + } } EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock); @@ -1757,7 +1764,11 @@ static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev) /* next window: if READY, proceed, if LOCKED, stop the trace */ if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) { - schedule_work(&msc->work); + if (msc->stop_on_full) + schedule_work(&msc->work); + else + msc->switch_on_unlock = next_win; + return IRQ_HANDLED; } @@ -2050,11 +2061,36 @@ win_switch_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_WO(win_switch); +static ssize_t stop_on_full_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct msc *msc = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", msc->stop_on_full); +} + +static ssize_t stop_on_full_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct msc *msc = dev_get_drvdata(dev); + int ret; + + ret = kstrtobool(buf, &msc->stop_on_full); + if (ret) + return ret; + + return size; +} + +static DEVICE_ATTR_RW(stop_on_full); + static struct attribute *msc_output_attrs[] = { &dev_attr_wrap.attr, &dev_attr_mode.attr, &dev_attr_nr_pages.attr, &dev_attr_win_switch.attr, + &dev_attr_stop_on_full.attr, NULL, }; -- 2.25.1