From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EB9F22FF160 for ; Mon, 22 Dec 2025 13:12:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766409171; cv=none; b=riT4XxlFaUSKsHuMcH+xy9Nu7wBxzB+M4ifvfhk7lP0Avo9KN06KayVvNMVzKX7qVTx3S6nthAVH30rFDF+SyrEOqVxzlpKtxkLo5KJmlxYs+fXg+kmUij9Dxo1ElRwH1EAYE/LEyMJd4UZnFU/jb5Zmdk5bhyNW1cv08NJ3V1U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766409171; c=relaxed/simple; bh=FLeLzWeLBG++1+4+g7ExfwWDtcrMmCDJDYJanMqCZa4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mSLXAV+tJu6Gg/fz81usxeZGZxVYjuXSHPCO9jOzKzHfS33GcWUvsEHlC4WsXW6TKTiPPUXe/Du9Pk9LhZKqfxSmuLzfbS3Cqa6ZZOOh3TpcaL4sH1ZsJdRcOucvGDfWSfNvlpcF6KYmINsVDl5tyQm36opBCIxbM8BIvYhqtcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 229AC497; Mon, 22 Dec 2025 05:12:42 -0800 (PST) Received: from [10.57.78.114] (unknown [10.57.78.114]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 85A143F778; Mon, 22 Dec 2025 05:12:47 -0800 (PST) Message-ID: <9899b6c2-2bdf-41b8-9156-dcf1b611da39@arm.com> Date: Mon, 22 Dec 2025 13:12:45 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 4/4] coresight: tpda: add sysfs node to flush specific port Content-Language: en-GB To: Jie Gan , Mike Leach , James Clark , Alexander Shishkin , Tingwei Zhang Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tao Zhang References: <20251222-add_sysfs_nodes_to_configure_tpda-v6-0-b27143d45c86@oss.qualcomm.com> <20251222-add_sysfs_nodes_to_configure_tpda-v6-4-b27143d45c86@oss.qualcomm.com> From: Suzuki K Poulose In-Reply-To: <20251222-add_sysfs_nodes_to_configure_tpda-v6-4-b27143d45c86@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 22/12/2025 06:02, Jie Gan wrote: > From: Tao Zhang > > Setting bit i in the TPDA_FLUSH_CR register initiates a flush request > for port i, forcing the data to synchronize and be transmitted to the > sink device. > > Signed-off-by: Tao Zhang > Reviewed-by: James Clark > Co-developed-by: Jie Gan > Signed-off-by: Jie Gan > --- > .../ABI/testing/sysfs-bus-coresight-devices-tpda | 7 ++++ > drivers/hwtracing/coresight/coresight-tpda.c | 40 ++++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-tpda.h | 1 + > 3 files changed, 48 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda > index d359d90dca72..df8f03d4b573 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda > @@ -51,3 +51,10 @@ Description: > mode 0 - COUNT[11:0] value represents the approximate number of bytes moved between two ASYNC packet requests > mode 1 - the bits COUNT[11:7] are used as a power of 2. for example, we could insert an async packet every 8K > data by writing a value 13 to the COUNT[11:7] field. > + > +What: /sys/bus/coresight/devices//port_flush_req > +Date: December 2025 > +KernelVersion: 6.19 > +Contact: Jinlong Mao , Tao Zhang , Jie Gan > +Description: > + (RW) Configure the bit i to requests a flush operation of port i on the TPDA. Does this have similar semantics as the "global_flush_req" for "Read" ? i.e., the bit stays set until the request completes ? Otherwise, why isn't this Write only ? I don't see the point of "Reading" this value back. Suzuki > diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c > index 7baa8a0965d3..f79fea4fbb2c 100644 > --- a/drivers/hwtracing/coresight/coresight-tpda.c > +++ b/drivers/hwtracing/coresight/coresight-tpda.c > @@ -430,9 +430,49 @@ static ssize_t syncr_mode_store(struct device *dev, > } > static DEVICE_ATTR_RW(syncr_mode); > > +static ssize_t port_flush_req_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent); > + unsigned long val; > + > + if (!drvdata->csdev->refcnt) > + return -EINVAL; > + > + guard(spinlock)(&drvdata->spinlock); > + val = readl_relaxed(drvdata->base + TPDA_FLUSH_CR); > + > + return sysfs_emit(buf, "0x%lx\n", val); > +} > + > +static ssize_t port_flush_req_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, > + size_t size) > +{ > + struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent); > + u32 val; > + > + if (kstrtou32(buf, 0, &val)) > + return -EINVAL; > + > + if (!drvdata->csdev->refcnt || !val) > + return -EINVAL; > + > + guard(spinlock)(&drvdata->spinlock); > + CS_UNLOCK(drvdata->base); > + writel_relaxed(val, drvdata->base + TPDA_FLUSH_CR); > + CS_LOCK(drvdata->base); > + > + return size; > +} > +static DEVICE_ATTR_RW(port_flush_req); > + > static struct attribute *tpda_attrs[] = { > &dev_attr_global_flush_req.attr, > &dev_attr_syncr_mode.attr, > + &dev_attr_port_flush_req.attr, > tpda_trig_sysfs_rw(freq_ts_enable, FREQTS), > tpda_trig_sysfs_rw(trig_freq_enable, FRIE), > tpda_trig_sysfs_rw(trig_flag_ts_enable, FLRIE), > diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h > index 1d2de50bb9f9..ef1ce2ce36a9 100644 > --- a/drivers/hwtracing/coresight/coresight-tpda.h > +++ b/drivers/hwtracing/coresight/coresight-tpda.h > @@ -10,6 +10,7 @@ > #define TPDA_Pn_CR(n) (0x004 + (n * 4)) > #define TPDA_FPID_CR (0x084) > #define TPDA_SYNCR (0x08C) > +#define TPDA_FLUSH_CR (0x090) > > /* Cross trigger global (all ports) flush request bit */ > #define TPDA_CR_FLREQ BIT(0) >