Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Lu Hongfei <luhongfei@vivo.com>
To:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Bart Van Assche <bvanassche@acm.org>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Bean Huo <beanhuo@micron.com>,
        Jinyoung Choi <j-young.choi@samsung.com>,
        Lu Hongfei <luhongfei@vivo.com>,
        Daniil Lunev <dlunev@chromium.org>,
        Peter Wang <peter.wang@mediatek.com>,
        linux-scsi@vger.kernel.org (open list:UNIVERSAL FLASH STORAGE HOST
        CONTROLLER DRIVER), linux-kernel@vger.kernel.org (open list)
Cc:     opensource.kernel@vivo.com
Subject: [PATCH v3] scsi: ufs: wb: Add explicit flush_threshold sysfs attribute
Date:   Fri,  9 Jun 2023 11:03:55 +0800
Message-Id: <20230609030357.64360-1-luhongfei@vivo.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?j7b9s3w1x2/17R9XNakWb/H3R3xC+T6XG9kY0gTww9A0SSvf+5iIIhF/nbKd?=
 =?us-ascii?Q?JpgqyEdKDbGVrytKAmjWSPwIz3kvY3ouVbHJx0TW7BghMcgyTzfR8UiXC6Wc?=
 =?us-ascii?Q?RZJvmZW/NmxUUPnOeksA45QlKtQDdJP9BOL9TraXrMEHvzDOB9XSijy0FeOc?=
 =?us-ascii?Q?kLeQnaBah3N1wx1+ehgpgUI7cv7kJQeinEjNBIO41jCoXbbZa4s1V2iV19Vr?=
 =?us-ascii?Q?VtBum7trL4o1oqXlDmbQ+/CmMIy5wnLwNYDtM7HFtaMRoS3BDiJRLYOdQB6l?=
 =?us-ascii?Q?dvDP71b8XmlO+LJU6OxtoRf6aMkzih3NKat0GZz9EnuzeLi399ba1mhIcFEX?=
 =?us-ascii?Q?nwbRhRapzhijwdxaK4I0Dj4W28COgyScW1KzJHcVi2nAFWdxgk6WbpQhhcMY?=
 =?us-ascii?Q?SDvfuX1WtH7xV7q4r8hvvrhxx7/gyNWZDUlups2Bd8yUbiTSuXOJeGoDcDC4?=
 =?us-ascii?Q?W1JBypKHtbFtDGr2I3K7ZqEJFh24SoNBtvOS4WlMtfDvxp4LUEa8WpIiApg/?=
 =?us-ascii?Q?4Ui60LS4+ZGRB4WPZqg38NUbDLiVckQ3CcqVqMXr2JzmOXjFVtHtABQDz1er?=
 =?us-ascii?Q?ZqDZi4l3UJ0+t05FLCCzeiHVRtjGNSEPoCIb2xlvrWgUGfJudQqn/jRCFW1B?=
 =?us-ascii?Q?N1Zqq/lHzUKW6U/iLfRZ5DN0UBvizv3Uds8Py42LtJraPdCrb8Gu7poWRqls?=
 =?us-ascii?Q?PAf5WsoiYDZM6kFCGbFJBN0N4BEqMfO+c4Y8jRJmI1WQ/1OuIx+CBbYpys7E?=
 =?us-ascii?Q?eZc7S34mVcvZM5+rM/4r2gAIZCOHsGjMQXJxW4y0EoyEqIl9DwFVdKLhGflN?=
 =?us-ascii?Q?geaS/pvnnMLprc1BvOurGxbUf4Qy+982RhVfxbNXrSOGr+4TIjdzKTBr0uMl?=
 =?us-ascii?Q?FcG7hPXDmL0OrUJ3cF7cCfVnrakh7fFO6KcF34Hc3vdh17RM9SWS6RgTOIz4?=
 =?us-ascii?Q?o35Adp566P1+uNCWUtdQdHjrpMlUo1Vmk1X57lbxzc80WxEMSfolzxn7alfN?=
 =?us-ascii?Q?c7ytg82HTvb1lpLiZeDUP05vgrjMTAqCPw2/z5hBhgPXWELsilQkwqay3t93?=
 =?us-ascii?Q?k/8uvCk2zAvveyShAIAfyLOR00VLfu9Lp64k3ol9u7Vn0GSCH1xe+8xJzivq?=
 =?us-ascii?Q?OLmtRddIUI+YElsSUcqbOv5IVUuTXREsq//L8m04cML+T+/igsyK6tQNUGOm?=
 =?us-ascii?Q?4BC7Uvcnxegdcbet3i9GsKe4MHZOCC0n5L/G09bAYqkSpkqnN5uLlON5Wnsm?=
 =?us-ascii?Q?HBij+xugg2MbudUDblCyvGfpZCFzAuGhfAAyTfpG1DCeOYfga6O0pYiZljIU?=
 =?us-ascii?Q?yxXKX9pUiNXWKF4Ul+yS70BghmoUQZ+7Fcv8ysBvqzDoOYjkTQm1TCW79Poi?=
 =?us-ascii?Q?stE9L7qBQ6TbbHwtL5wf+J1WsHyXNDcIFCbUBHN5L9D3kTWDic8Im7OAAAnY?=
 =?us-ascii?Q?Nbp3K53pVIDxO+Y8vKCrP6sSl4OqV2daaHgwsOqb6BWS4mK2zWGgjWPuJqei?=
 =?us-ascii?Q?gUlTRlgaASntzF5JmzRoyMYpwV4B5OxaiZuwSXihqTeVE2afDdsf8a+h5XoJ?=
 =?us-ascii?Q?PGQdVmbOcUBcg7x1jlxfaYogyXvCQ5G/e0sjxLMY?=
X-OriginatorOrg: vivo.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 084d4f03-0cdf-41ad-ae05-08db68963267
X-MS-Exchange-CrossTenant-AuthSource: TYZPR06MB6697.apcprd06.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jun 2023 03:04:10.5121
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 923e42dc-48d5-4cbe-b582-1a797a6412ed
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: wq/4qerwqlZOoDhmKrUXeDEVscByPudhmdviUz7n6xQHr8140hGa/fF6bMsNBh+wALvSi8ASgUc2bBhmB8i2Qg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: TYZPR06MB4318
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,
        URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

There are three flags that control Write Booster Feature:

    1. WB ON/OFF
    2. WB Hibern Flush ON/OFF (implicitly)
    3. WB Flush ON/OFF (explicit)

In the case of "Hibern Flush", one of the conditions for flush WB buffer is
that avail_wb_buff < wb_flush_threshold.

As we know, different users have different requirements for power
consumption and performance. Therefore, we need the ability to manually
set wb_flush_threshold, so that users can easily and flexibly adjust
the wb_flush_threshold value, thereby achieving a balance between power
consumption and performance.

So the sysfs attribute that controls this is necessary.

The meaning of wb_flush_threshold is the percentage of WB's total size,
such as 1 representing 10%, 2 representing 20%, and so on.

Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
---
The modifications made compared to the previous version are as follows:
1. Using 'wb_flush_threshold == 0' insted of 'wb_flush_threshold <= 0'.

 drivers/ufs/core/ufs-sysfs.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index cdf3d5f2b77b..347207f4e8ee
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -298,6 +298,37 @@ static ssize_t enable_wb_buf_flush_store(struct device *dev,
 	return res < 0 ? res : count;
 }
 
+static ssize_t wb_flush_threshold_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", hba->vps->wb_flush_threshold);
+}
+
+static ssize_t wb_flush_threshold_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned int wb_flush_threshold;
+
+	if (kstrtouint(buf, 0, &wb_flush_threshold))
+		return -EINVAL;
+
+	/* The range of values for wb_flush_threshold is (0,10] */
+	if (wb_flush_threshold > UFS_WB_BUF_REMAIN_PERCENT(100) ||
+		wb_flush_threshold == 0) {
+		dev_err(dev, "The value of wb_flush_threshold is invalid!\n");
+		return -EINVAL;
+	}
+
+	hba->vps->wb_flush_threshold = wb_flush_threshold;
+
+	return count;
+}
+
 static DEVICE_ATTR_RW(rpm_lvl);
 static DEVICE_ATTR_RO(rpm_target_dev_state);
 static DEVICE_ATTR_RO(rpm_target_link_state);
@@ -307,6 +338,7 @@ static DEVICE_ATTR_RO(spm_target_link_state);
 static DEVICE_ATTR_RW(auto_hibern8);
 static DEVICE_ATTR_RW(wb_on);
 static DEVICE_ATTR_RW(enable_wb_buf_flush);
+static DEVICE_ATTR_RW(wb_flush_threshold);
 
 static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_rpm_lvl.attr,
@@ -318,6 +350,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_auto_hibern8.attr,
 	&dev_attr_wb_on.attr,
 	&dev_attr_enable_wb_buf_flush.attr,
+	&dev_attr_wb_flush_threshold.attr,
 	NULL
 };
 
-- 
2.39.0