[PATCH v2] ufs: core: Add WB buffer resize support

[PATCH v2] ufs: core: Add WB buffer resize support

[Huan Tang]

Support WB buffer resize function through sysfs, the host can obtain
resize hint and resize status and enable the resize operation. To
achieve this goals, three sysfs nodes have been added:
	1. wb_toggle_buf_resize
	2. wb_buf_resize_hint
	3. wb_buf_resize_status

The detailed definition of the three nodes can be found in the sysfs
documentation.

Changelog
===
	v1 - > v2:
	remove unused variable "u8 index",
	drivers/ufs/core/ufs-sysfs.c:419:12: warning: variable 'index'
	set but not used.

v1
	https://lore.kernel.org/all/20241025085924.4855-1-tanghuan@vivo.com/

Signed-off-by: Huan Tang <tanghuan@vivo.com>
Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
---
 Documentation/ABI/testing/sysfs-driver-ufs | 52 ++++++++++++++++++++++
 drivers/ufs/core/ufs-sysfs.c               | 43 ++++++++++++++++++
 drivers/ufs/core/ufshcd.c                  | 15 +++++++
 include/ufs/ufs.h                          |  5 ++-
 include/ufs/ufshcd.h                       |  1 +
 5 files changed, 115 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index 5fa6655aee84..dbaa84277801 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1559,3 +1559,55 @@ Description:
 		Symbol - HCMID. This file shows the UFSHCD manufacturer id.
 		The Manufacturer ID is defined by JEDEC in JEDEC-JEP106.
 		The file is read only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/wb_toggle_buf_resize
+What:		/sys/bus/platform/devices/*.ufs/wb_toggle_buf_resize
+Date:		Qct 2024
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		The host can decrease or increase the WriteBooster Buffer size by setting
+		this file.
+
+		======  ======================================
+		00h  Idle (There is no resize operation)
+		01h  Decrease WriteBooster Buffer Size
+		02h  Increase WriteBooster Buffer Size
+		Others  Reserved
+		======  ======================================
+
+		The file is write only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/attributes/wb_buf_resize_hint
+What:		/sys/bus/platform/devices/*.ufs/attributes/wb_buf_resize_hint
+Date:		Qct 2024
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		wb_buf_resize_hint indicates hint information about which type of resize for
+		WriteBooster Buffer is recommended by the device.
+
+		======  ======================================
+		00h  Recommend keep the buffer size
+		01h  Recommend to decrease the buffer size
+		02h  Recommend to increase the buffer size
+		Others: Reserved
+		======  ======================================
+
+		The file is read only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/attributes/wb_buf_resize_status
+What:		/sys/bus/platform/devices/*.ufs/attributes/wb_buf_resize_status
+Date:		Qct 2024
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		The host can check the Resize operation status of the WriteBooster Buffer
+		by reading this file.
+
+		======  ========================================
+		00h  Idle (resize operation is not issued)
+		01h  Resize operation in progress
+		02h  Resize operation completed successfully
+		03h  Resize operation general failure
+		Others  Reserved
+		======  ========================================
+
+		The file is read only.
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 265f21133b63..bb21982394c8 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -411,6 +411,43 @@ static ssize_t wb_flush_threshold_store(struct device *dev,
 	return count;
 }
 
+static ssize_t wb_toggle_buf_resize_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_buf_resize_op;
+	ssize_t res;
+
+	if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled ||
+		!hba->dev_info.b_presrv_uspc_en) {
+		dev_err(dev, "The WB buf resize is not allowed!\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (kstrtouint(buf, 0, &wb_buf_resize_op))
+		return -EINVAL;
+
+	if (wb_buf_resize_op != 0x01 && wb_buf_resize_op != 0x02) {
+		dev_err(dev, "The operation %u is invalid!\n", wb_buf_resize_op);
+		return -EINVAL;
+	}
+
+	down(&hba->host_sem);
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		res = -EBUSY;
+		goto out;
+	}
+
+	index = ufshcd_wb_get_query_index(hba);
+	ufshcd_rpm_get_sync(hba);
+	res = ufshcd_wb_toggle_buf_resize(hba, wb_buf_resize_op);
+	ufshcd_rpm_put_sync(hba);
+
+out:
+	up(&hba->host_sem);
+	return res < 0 ? res : count;
+}
+
 /**
  * pm_qos_enable_show - sysfs handler to show pm qos enable value
  * @dev: device associated with the UFS controller
@@ -468,6 +505,7 @@ 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 DEVICE_ATTR_WO(wb_toggle_buf_resize);
 static DEVICE_ATTR_RW(rtc_update_ms);
 static DEVICE_ATTR_RW(pm_qos_enable);
 
@@ -482,6 +520,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
 	&dev_attr_wb_on.attr,
 	&dev_attr_enable_wb_buf_flush.attr,
 	&dev_attr_wb_flush_threshold.attr,
+	&dev_attr_wb_toggle_buf_resize.attr,
 	&dev_attr_rtc_update_ms.attr,
 	&dev_attr_pm_qos_enable.attr,
 	NULL
@@ -1526,6 +1565,8 @@ UFS_ATTRIBUTE(wb_flush_status, _WB_FLUSH_STATUS);
 UFS_ATTRIBUTE(wb_avail_buf, _AVAIL_WB_BUFF_SIZE);
 UFS_ATTRIBUTE(wb_life_time_est, _WB_BUFF_LIFE_TIME_EST);
 UFS_ATTRIBUTE(wb_cur_buf, _CURR_WB_BUFF_SIZE);
+UFS_ATTRIBUTE(wb_buf_resize_hint, _WB_BUF_RESIZE_HINT);
+UFS_ATTRIBUTE(wb_buf_resize_status, _WB_BUF_RESIZE_STATUS);
 
 
 static struct attribute *ufs_sysfs_attributes[] = {
@@ -1549,6 +1590,8 @@ static struct attribute *ufs_sysfs_attributes[] = {
 	&dev_attr_wb_avail_buf.attr,
 	&dev_attr_wb_life_time_est.attr,
 	&dev_attr_wb_cur_buf.attr,
+	&dev_attr_wb_buf_resize_hint.attr,
+	&dev_attr_wb_buf_resize_status.attr,
 	NULL,
 };
 
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 630409187c10..c28915debab6 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6167,6 +6167,21 @@ static bool ufshcd_wb_need_flush(struct ufs_hba *hba)
 	return ufshcd_wb_presrv_usrspc_keep_vcc_on(hba, avail_buf);
 }
 
+int ufshcd_wb_toggle_buf_resize(struct ufs_hba *hba, u32 op)
+{
+	int ret;
+	u8 index;
+
+	index = ufshcd_wb_get_query_index(hba);
+	ret = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+				   QUERY_ATTR_IDN_WB_BUF_RESIZE_EN, index, 0, &op);
+	if (ret)
+		dev_err(hba->dev, "%s: Enable WB buf resize operation failed %d\n",
+			__func__, ret);
+
+	return ret;
+}
+
 static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
 {
 	struct ufs_hba *hba = container_of(to_delayed_work(work),
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index e594abe5d05f..f737d98044ac 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -181,7 +181,10 @@ enum attr_idn {
 	QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
 	QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE        = 0x1F,
 	QUERY_ATTR_IDN_EXT_IID_EN		= 0x2A,
-	QUERY_ATTR_IDN_TIMESTAMP		= 0x30
+	QUERY_ATTR_IDN_TIMESTAMP		= 0x30,
+	QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT	= 0x3C,
+	QUERY_ATTR_IDN_WB_BUF_RESIZE_EN		= 0x3D,
+	QUERY_ATTR_IDN_WB_BUF_RESIZE_STATUS	= 0x3E,
 };
 
 /* Descriptor idn for Query requests */
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index a95282b9f743..cbe208ce9293 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1454,6 +1454,7 @@ int ufshcd_advanced_rpmb_req_handler(struct ufs_hba *hba, struct utp_upiu_req *r
 				     struct scatterlist *sg_list, enum dma_data_direction dir);
 int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
 int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable);
+int ufshcd_wb_toggle_buf_resize(struct ufs_hba *hba, u32 op);
 int ufshcd_suspend_prepare(struct device *dev);
 int __ufshcd_suspend_prepare(struct device *dev, bool rpm_ok_for_spm);
 void ufshcd_resume_complete(struct device *dev);
-- 
2.39.0

Re: [PATCH v2] ufs: core: Add WB buffer resize support

[kernel test robot]

Hi Huan,

kernel test robot noticed the following build errors:

[auto build test ERROR on jejb-scsi/for-next]
[also build test ERROR on mkp-scsi/for-next linus/master v6.12-rc4 next-20241025]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Huan-Tang/ufs-core-Add-WB-buffer-resize-support/20241026-084545
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
patch link:    https://lore.kernel.org/r/20241026004423.135-1-tanghuan%40vivo.com
patch subject: [PATCH v2] ufs: core: Add WB buffer resize support
config: i386-randconfig-141-20241026 (https://download.01.org/0day-ci/archive/20241027/202410270024.rwb7xAgC-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241027/202410270024.rwb7xAgC-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410270024.rwb7xAgC-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/ufs/core/ufs-sysfs.c: In function 'wb_toggle_buf_resize_store':
>> drivers/ufs/core/ufs-sysfs.c:441:9: error: 'index' undeclared (first use in this function)
     441 |         index = ufshcd_wb_get_query_index(hba);
         |         ^~~~~
   drivers/ufs/core/ufs-sysfs.c:441:9: note: each undeclared identifier is reported only once for each function it appears in

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for GET_FREE_REGION
   Depends on [n]: SPARSEMEM [=n]
   Selected by [m]:
   - RESOURCE_KUNIT_TEST [=m] && RUNTIME_TESTING_MENU [=y] && KUNIT [=y]


vim +/index +441 drivers/ufs/core/ufs-sysfs.c

   413	
   414	static ssize_t wb_toggle_buf_resize_store(struct device *dev,
   415			struct device_attribute *attr, const char *buf, size_t count)
   416	{
   417		struct ufs_hba *hba = dev_get_drvdata(dev);
   418		unsigned int wb_buf_resize_op;
   419		ssize_t res;
   420	
   421		if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled ||
   422			!hba->dev_info.b_presrv_uspc_en) {
   423			dev_err(dev, "The WB buf resize is not allowed!\n");
   424			return -EOPNOTSUPP;
   425		}
   426	
   427		if (kstrtouint(buf, 0, &wb_buf_resize_op))
   428			return -EINVAL;
   429	
   430		if (wb_buf_resize_op != 0x01 && wb_buf_resize_op != 0x02) {
   431			dev_err(dev, "The operation %u is invalid!\n", wb_buf_resize_op);
   432			return -EINVAL;
   433		}
   434	
   435		down(&hba->host_sem);
   436		if (!ufshcd_is_user_access_allowed(hba)) {
   437			res = -EBUSY;
   438			goto out;
   439		}
   440	
 > 441		index = ufshcd_wb_get_query_index(hba);
   442		ufshcd_rpm_get_sync(hba);
   443		res = ufshcd_wb_toggle_buf_resize(hba, wb_buf_resize_op);
   444		ufshcd_rpm_put_sync(hba);
   445	
   446	out:
   447		up(&hba->host_sem);
   448		return res < 0 ? res : count;
   449	}
   450	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v2] ufs: core: Add WB buffer resize support

[kernel test robot]

Hi Huan,

kernel test robot noticed the following build errors:

[auto build test ERROR on jejb-scsi/for-next]
[also build test ERROR on mkp-scsi/for-next linus/master v6.12-rc4 next-20241025]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Huan-Tang/ufs-core-Add-WB-buffer-resize-support/20241026-084545
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
patch link:    https://lore.kernel.org/r/20241026004423.135-1-tanghuan%40vivo.com
patch subject: [PATCH v2] ufs: core: Add WB buffer resize support
config: i386-buildonly-randconfig-001-20241026 (https://download.01.org/0day-ci/archive/20241027/202410270108.zrM5GjRx-lkp@intel.com/config)
compiler: clang version 19.1.2 (https://github.com/llvm/llvm-project 7ba7d8e2f7b6445b60679da826210cdde29eaf8b)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241027/202410270108.zrM5GjRx-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410270108.zrM5GjRx-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/ufs/core/ufs-sysfs.c:12:
   In file included from drivers/ufs/core/ufshcd-priv.h:7:
   In file included from include/ufs/ufshcd.h:16:
   In file included from include/linux/blk-crypto-profile.h:9:
   In file included from include/linux/bio.h:10:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:8:
   In file included from include/linux/cacheflush.h:5:
   In file included from arch/x86/include/asm/cacheflush.h:5:
   In file included from include/linux/mm.h:2213:
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> drivers/ufs/core/ufs-sysfs.c:441:2: error: use of undeclared identifier 'index'
     441 |         index = ufshcd_wb_get_query_index(hba);
         |         ^
   1 warning and 1 error generated.

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for GET_FREE_REGION
   Depends on [n]: SPARSEMEM [=n]
   Selected by [y]:
   - RESOURCE_KUNIT_TEST [=y] && RUNTIME_TESTING_MENU [=y] && KUNIT [=y]


vim +/index +441 drivers/ufs/core/ufs-sysfs.c

   413	
   414	static ssize_t wb_toggle_buf_resize_store(struct device *dev,
   415			struct device_attribute *attr, const char *buf, size_t count)
   416	{
   417		struct ufs_hba *hba = dev_get_drvdata(dev);
   418		unsigned int wb_buf_resize_op;
   419		ssize_t res;
   420	
   421		if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled ||
   422			!hba->dev_info.b_presrv_uspc_en) {
   423			dev_err(dev, "The WB buf resize is not allowed!\n");
   424			return -EOPNOTSUPP;
   425		}
   426	
   427		if (kstrtouint(buf, 0, &wb_buf_resize_op))
   428			return -EINVAL;
   429	
   430		if (wb_buf_resize_op != 0x01 && wb_buf_resize_op != 0x02) {
   431			dev_err(dev, "The operation %u is invalid!\n", wb_buf_resize_op);
   432			return -EINVAL;
   433		}
   434	
   435		down(&hba->host_sem);
   436		if (!ufshcd_is_user_access_allowed(hba)) {
   437			res = -EBUSY;
   438			goto out;
   439		}
   440	
 > 441		index = ufshcd_wb_get_query_index(hba);
   442		ufshcd_rpm_get_sync(hba);
   443		res = ufshcd_wb_toggle_buf_resize(hba, wb_buf_resize_op);
   444		ufshcd_rpm_put_sync(hba);
   445	
   446	out:
   447		up(&hba->host_sem);
   448		return res < 0 ? res : count;
   449	}
   450	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

Hi Tang,

I saw that "Both UFS 4.1 and UFS 5.0 are currently in development" have
not been officially published yet. Are you keen to incorporate features
based on an unpublished standard?


Kind regards,
Bean

On Sat, 2024-10-26 at 08:44 +0800, Huan Tang wrote:
> Support WB buffer resize function through sysfs, the host can obtain
> resize hint and resize status and enable the resize operation. To
> achieve this goals, three sysfs nodes have been added:
>         1. wb_toggle_buf_resize
>         2. wb_buf_resize_hint
>         3. wb_buf_resize_status
> 
> The detailed definition of the three nodes can be found in the sysfs
> documentation.
> 
> Changelog
> ===
>         v1 - > v2:
>         remove unused variable "u8 index",
>         drivers/ufs/core/ufs-sysfs.c:419:12: warning: variable
> 'index'
>         set but not used.
> 
> v1
>         
> https://lore.kernel.org/all/20241025085924.4855-1-tanghuan@vivo.com/
> 
> Signed-off-by: Huan Tang <tanghuan@vivo.com>
> Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
> ---
>  Documentation/ABI/testing/sysfs-driver-ufs | 52
> ++++++++++++++++++++++
>  drivers/ufs/core/ufs-sysfs.c               | 43 ++++++++++++++++++
>  drivers/ufs/core/ufshcd.c                  | 15 +++++++
>  include/ufs/ufs.h                          |  5 ++-
>  include/ufs/ufshcd.h                       |  1 +
>  5 files changed, 115 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ufs
> b/Documentation/ABI/testing/sysfs-driver-ufs
> index 5fa6655aee84..dbaa84277801 100644
> --- a/Documentation/ABI/testing/sysfs-driver-ufs
> +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> @@ -1559,3 +1559,55 @@ Description:
>                 Symbol - HCMID. This file shows the UFSHCD
> manufacturer id.
>                 The Manufacturer ID is defined by JEDEC in JEDEC-
> JEP106.
>                 The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/wb_toggle_buf_resi
> ze
> +What:          /sys/bus/platform/devices/*.ufs/wb_toggle_buf_resize
> +Date:          Qct 2024
> +Contact:       Huan Tang <tanghuan@vivo.com>
> +Description:
> +               The host can decrease or increase the WriteBooster
> Buffer size by setting
> +               this file.
> +
> +               ======  ======================================
> +               00h  Idle (There is no resize operation)
> +               01h  Decrease WriteBooster Buffer Size
> +               02h  Increase WriteBooster Buffer Size
> +               Others  Reserved
> +               ======  ======================================
> +
> +               The file is write only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/attributes/wb_buf_
> resize_hint
> +What:          /sys/bus/platform/devices/*.ufs/attributes/wb_buf_res
> ize_hint
> +Date:          Qct 2024
> +Contact:       Huan Tang <tanghuan@vivo.com>
> +Description:
> +               wb_buf_resize_hint indicates hint information about
> which type of resize for
> +               WriteBooster Buffer is recommended by the device.
> +
> +               ======  ======================================
> +               00h  Recommend keep the buffer size
> +               01h  Recommend to decrease the buffer size
> +               02h  Recommend to increase the buffer size
> +               Others: Reserved
> +               ======  ======================================
> +
> +               The file is read only.
> +
> +What:          /sys/bus/platform/drivers/ufshcd/*/attributes/wb_buf_
> resize_status
> +What:          /sys/bus/platform/devices/*.ufs/attributes/wb_buf_res
> ize_status
> +Date:          Qct 2024
> +Contact:       Huan Tang <tanghuan@vivo.com>
> +Description:
> +               The host can check the Resize operation status of the
> WriteBooster Buffer
> +               by reading this file.
> +
> +               ======  ========================================
> +               00h  Idle (resize operation is not issued)
> +               01h  Resize operation in progress
> +               02h  Resize operation completed successfully
> +               03h  Resize operation general failure
> +               Others  Reserved
> +               ======  ========================================
> +
> +               The file is read only.
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-
> sysfs.c
> index 265f21133b63..bb21982394c8 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -411,6 +411,43 @@ static ssize_t wb_flush_threshold_store(struct
> device *dev,
>         return count;
>  }
>  
> +static ssize_t wb_toggle_buf_resize_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_buf_resize_op;
> +       ssize_t res;
> +
> +       if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled
> ||
> +               !hba->dev_info.b_presrv_uspc_en) {
> +               dev_err(dev, "The WB buf resize is not allowed!\n");
> +               return -EOPNOTSUPP;
> +       }
> +
> +       if (kstrtouint(buf, 0, &wb_buf_resize_op))
> +               return -EINVAL;
> +
> +       if (wb_buf_resize_op != 0x01 && wb_buf_resize_op != 0x02) {
> +               dev_err(dev, "The operation %u is invalid!\n",
> wb_buf_resize_op);
> +               return -EINVAL;
> +       }
> +
> +       down(&hba->host_sem);
> +       if (!ufshcd_is_user_access_allowed(hba)) {
> +               res = -EBUSY;
> +               goto out;
> +       }
> +
> +       index = ufshcd_wb_get_query_index(hba);
> +       ufshcd_rpm_get_sync(hba);
> +       res = ufshcd_wb_toggle_buf_resize(hba, wb_buf_resize_op);
> +       ufshcd_rpm_put_sync(hba);
> +
> +out:
> +       up(&hba->host_sem);
> +       return res < 0 ? res : count;
> +}
> +
>  /**
>   * pm_qos_enable_show - sysfs handler to show pm qos enable value
>   * @dev: device associated with the UFS controller
> @@ -468,6 +505,7 @@ 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 DEVICE_ATTR_WO(wb_toggle_buf_resize);
>  static DEVICE_ATTR_RW(rtc_update_ms);
>  static DEVICE_ATTR_RW(pm_qos_enable);
>  
> @@ -482,6 +520,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[]
> = {
>         &dev_attr_wb_on.attr,
>         &dev_attr_enable_wb_buf_flush.attr,
>         &dev_attr_wb_flush_threshold.attr,
> +       &dev_attr_wb_toggle_buf_resize.attr,
>         &dev_attr_rtc_update_ms.attr,
>         &dev_attr_pm_qos_enable.attr,
>         NULL
> @@ -1526,6 +1565,8 @@ UFS_ATTRIBUTE(wb_flush_status,
> _WB_FLUSH_STATUS);
>  UFS_ATTRIBUTE(wb_avail_buf, _AVAIL_WB_BUFF_SIZE);
>  UFS_ATTRIBUTE(wb_life_time_est, _WB_BUFF_LIFE_TIME_EST);
>  UFS_ATTRIBUTE(wb_cur_buf, _CURR_WB_BUFF_SIZE);
> +UFS_ATTRIBUTE(wb_buf_resize_hint, _WB_BUF_RESIZE_HINT);
> +UFS_ATTRIBUTE(wb_buf_resize_status, _WB_BUF_RESIZE_STATUS);
>  
>  
>  static struct attribute *ufs_sysfs_attributes[] = {
> @@ -1549,6 +1590,8 @@ static struct attribute *ufs_sysfs_attributes[]
> = {
>         &dev_attr_wb_avail_buf.attr,
>         &dev_attr_wb_life_time_est.attr,
>         &dev_attr_wb_cur_buf.attr,
> +       &dev_attr_wb_buf_resize_hint.attr,
> +       &dev_attr_wb_buf_resize_status.attr,
>         NULL,
>  };
>  
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 630409187c10..c28915debab6 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -6167,6 +6167,21 @@ static bool ufshcd_wb_need_flush(struct
> ufs_hba *hba)
>         return ufshcd_wb_presrv_usrspc_keep_vcc_on(hba, avail_buf);
>  }
>  
> +int ufshcd_wb_toggle_buf_resize(struct ufs_hba *hba, u32 op)
> +{
> +       int ret;
> +       u8 index;
> +
> +       index = ufshcd_wb_get_query_index(hba);
> +       ret = ufshcd_query_attr_retry(hba,
> UPIU_QUERY_OPCODE_WRITE_ATTR,
> +                                  QUERY_ATTR_IDN_WB_BUF_RESIZE_EN,
> index, 0, &op);
> +       if (ret)
> +               dev_err(hba->dev, "%s: Enable WB buf resize operation
> failed %d\n",
> +                       __func__, ret);
> +
> +       return ret;
> +}
> +
>  static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct
> *work)
>  {
>         struct ufs_hba *hba = container_of(to_delayed_work(work),
> diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
> index e594abe5d05f..f737d98044ac 100644
> --- a/include/ufs/ufs.h
> +++ b/include/ufs/ufs.h
> @@ -181,7 +181,10 @@ enum attr_idn {
>         QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
>         QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE        = 0x1F,
>         QUERY_ATTR_IDN_EXT_IID_EN               = 0x2A,
> -       QUERY_ATTR_IDN_TIMESTAMP                = 0x30
> +       QUERY_ATTR_IDN_TIMESTAMP                = 0x30,
> +       QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT       = 0x3C,
> +       QUERY_ATTR_IDN_WB_BUF_RESIZE_EN         = 0x3D,
> +       QUERY_ATTR_IDN_WB_BUF_RESIZE_STATUS     = 0x3E,
>  };
>  
>  /* Descriptor idn for Query requests */
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index a95282b9f743..cbe208ce9293 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -1454,6 +1454,7 @@ int ufshcd_advanced_rpmb_req_handler(struct
> ufs_hba *hba, struct utp_upiu_req *r
>                                      struct scatterlist *sg_list,
> enum dma_data_direction dir);
>  int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
>  int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable);
> +int ufshcd_wb_toggle_buf_resize(struct ufs_hba *hba, u32 op);
>  int ufshcd_suspend_prepare(struct device *dev);
>  int __ufshcd_suspend_prepare(struct device *dev, bool
> rpm_ok_for_spm);
>  void ufshcd_resume_complete(struct device *dev);

Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bart Van Assche]

On 10/26/24 12:40 PM, Bean Huo wrote:
> I saw that "Both UFS 4.1 and UFS 5.0 are currently in development" have
> not been officially published yet. Are you keen to incorporate features
> based on an unpublished standard?

Hi Bean,

UFS WG members approved the WB buffer resize functionality through the
JEDEC voting process about one year ago. Isn't that sufficient to
implement this functionality in the kernel? See also the JC-64.1
December 7, 2023 meeting minutes.

Thanks,

Bart.

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

> -----Original Message-----
> From: Bart Van Assche <bvanassche@acm.org>
> Sent: Montag, 28. Oktober 2024 19:38
> To: Bean Huo <huobean@gmail.com>; Huan Tang <tanghuan@vivo.com>;
> linux-scsi@vger.kernel.org
> Cc: opensource.kernel@vivo.com
> Subject: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support
> 
> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless
> you recognize the sender and were expecting this message.
> 
> 
> On 10/26/24 12:40 PM, Bean Huo wrote:
> > I saw that "Both UFS 4.1 and UFS 5.0 are currently in development"
> > have not been officially published yet. Are you keen to incorporate
> > features based on an unpublished standard?
> 
> Hi Bean,
> 
> UFS WG members approved the WB buffer resize functionality through the
> JEDEC voting process about one year ago. Isn't that sufficient to implement
> this functionality in the kernel? See also the JC-64.1 December 7, 2023
> meeting minutes.
> 
> Thanks,
> 
> Bart.
> 

Bart,

That's not a reason we must implement it. Not everything that exists is reasonable, especially those things designed by humans. 

My question is, UFS 4.1 has not been officially published. However, I noticed that you have strongly supported this work. Even though I don't think it's necessary to enable a Sysfs node entry for this configuration.


Kind regards,
Bean

Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bart Van Assche]

On 10/28/24 1:04 PM, Bean Huo wrote:
> Even though I don't think it's necessary to enable a Sysfs node entry
> for this configuration.

Right, a motivation of why this functionality should be available
in sysfs is missing. An explanation should be added in the patch
description.

Thanks,

Bart.

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

> -----Original Message-----
> From: Bart Van Assche <bvanassche@acm.org>
> Sent: Montag, 28. Oktober 2024 21:10
> To: Bean Huo <beanhuo@micron.com>; Bean Huo <huobean@gmail.com>;
> Huan Tang <tanghuan@vivo.com>; linux-scsi@vger.kernel.org
> Cc: opensource.kernel@vivo.com
> Subject: Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support
> 
> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless
> you recognize the sender and were expecting this message.
> 
> 
> On 10/28/24 1:04 PM, Bean Huo wrote:
> > Even though I don't think it's necessary to enable a Sysfs node entry
> > for this configuration.
> 
> Right, a motivation of why this functionality should be available in sysfs is
> missing. An explanation should be added in the patch description.
> 
> Thanks,
> 
> Bart.

I would like to say this actually: committee approval of a ballot does not give a company or individual the ability to disclose the
feature outside of JEDEC.

Unless JEDEC has published details relating to a particular feature in a not-yet-board-approved standard, these details should be
considered proprietary to JEDEC members and not revealed outside of JEDEC until JEDEC board approval has occurred.  For UFS 4.1,
which will include the WB resize feature. Has not officially published yet.  Before that, there is no public information to release to
the community.  


Kind regards,
Bean

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Huan Tang]

> I would like to say this actually: committee approval of a ballot does not give a company or individual the ability to disclose the
> feature outside of JEDEC.

> Unless JEDEC has published details relating to a particular feature in a not-yet-board-approved standard, these details should be
> considered proprietary to JEDEC members and not revealed outside of JEDEC until JEDEC board approval has occurred.  For UFS 4.1,
> which will include the WB resize feature. Has not officially published yet.  Before that, there is no public information to release to
> the community.  


> Kind regards,
> Bean

Hi Bean,

JEDEC expects to release it in early November this year. The spec for this feature has been confirmed. 
Do we need to wait until the standard is officially released before discussing this submission?

Thanks
Huan

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Huan Tang]

> On 10/28/24 1:04 PM, Bean Huo wrote:
> > Even though I don't think it's necessary to enable a Sysfs node entry
> > for this configuration.
> 
> Right, a motivation of why this functionality should be available in sysfs is
> missing. An explanation should be added in the patch description.
> 
> Thanks,
> 
> Bart.

Hi Bean & Bart,

Motivation: Through the sysfs upper layer code, the WB resize function can be used in some scenarios, or related information can be obtained indirectly to implement different strategies;
What is your suggestion? sysfs? exception event? or?

Thanks
Huan

Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

On Tue, 2024-10-29 at 11:11 +0800, Huan Tang wrote:
> > On 10/28/24 1:04 PM, Bean Huo wrote:
> > > Even though I don't think it's necessary to enable a Sysfs node
> > > entry
> > > for this configuration.
> > 
> > Right, a motivation of why this functionality should be available
> > in sysfs is
> > missing. An explanation should be added in the patch description.
> > 
> > Thanks,
> > 
> > Bart.
> 
> Hi Bean & Bart,
> 
> Motivation: Through the sysfs upper layer code, the WB resize
> function can be used in some scenarios, or related information can be
> obtained indirectly to implement different strategies;
> What is your suggestion? sysfs? exception event? or?
> 
> Thanks
> Huan

hey Huan,

What specific scenarios would require enabling a sysfs node to control
this function? Dynamically adjusting the WriteBooster (WB) size on the
fly doesn’t seem ideal to me. From my perspective, the main case for
this feature is if the OEM didn’t correctly define or set the
WriteBooster Buffer size during manufacturing. Even then, adjusting the
WB buffer size wouldn’t be a frequent need. If JEDEC has found a reason
for this feature to be accepted, isn’t there already an interface
available to configure it? Why would we need a duplicate interface for
the same purpose?

Kind regards,
Bean

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Huan Tang]

> > > On 10/28/24 1:04 PM, Bean Huo wrote:
> > > > Even though I don't think it's necessary to enable a Sysfs node 
> > > > entry for this configuration.
> > >
> > > Right, a motivation of why this functionality should be available in 
> > > sysfs is missing. An explanation should be added in the patch 
> > > description.
> > >
> > > Thanks,
> > >
> > > Bart.
> >
> > Hi Bean & Bart,
> >
> > Motivation: Through the sysfs upper layer code, the WB resize function 
> > can be used in some scenarios, or related information can be obtained 
> > indirectly to implement different strategies; What is your suggestion? 
> > sysfs? exception event? or?
> >
> > Thanks
> > Huan
>
> hey Huan,
> 
> What specific scenarios would require enabling a sysfs node to control this function? Dynamically
> adjusting the WriteBooster (WB) size on the fly doesn’t seem ideal to me. From my perspective, the main
> case for this feature is if the OEM didn’t correctly define or set the WriteBooster Buffer size during
> manufacturing. Even then, adjusting the WB buffer size wouldn’t be a frequent need. If JEDEC has
> found a reason for this feature to be accepted, isn’t there already an interface available to configure it?
> Why would we need a duplicate interface for the same purpose?
> 
> Kind regards,
> Bean

Hi Bean,

Thanks for your reply

The scenario I'm thinking of right now： when the old phone transfers a large
amount of data to the new phone's APP (vivo calls it easyshare APP), we can 
explicitly resize the WB buffer.

Could you please explain this sentence(If JEDEC has found a reason for this feature
to be accepted, isn’t there already an interface available to configure it? Why
would we need a duplicate interface for the same purpose?) more simply so I 
can understand it better?

JEDEC draft comments:
The WriteBooster buffer size can be resized in preserve user space
configuration mode of WriteBooster by device implicitly. However, the
disadvantage of preserve user space mode of WriteBooster configuration is
that there could be performance degradation when the physical storage
used for the WriteBooster Buffer is returned to user space, since the device
has to make internal data structure adjustments as well as flush the
WriteBooster Buffer data. To minimize this disadvantage, the WriteBooster
Resize command is provided. The device only provides hint information to
the host whether the WriteBooster Buffer needs to be resized or not, and
the host can execute the WriteBooster Resize command based on this hint
information when there is no user IOs

Thanks
Huan

Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

On Tue, 2024-10-29 at 20:03 +0800, Huan Tang wrote:
> > > > On 10/28/24 1:04 PM, Bean Huo wrote:
> > > > > Even though I don't think it's necessary to enable a Sysfs
> > > > > node 
> > > > > entry for this configuration.
> > > > 
> > > > Right, a motivation of why this functionality should be
> > > > available in 
> > > > sysfs is missing. An explanation should be added in the patch 
> > > > description.
> > > > 
> > > > Thanks,
> > > > 
> > > > Bart.
> > > 
> > > Hi Bean & Bart,
> > > 
> > > Motivation: Through the sysfs upper layer code, the WB resize
> > > function 
> > > can be used in some scenarios, or related information can be
> > > obtained 
> > > indirectly to implement different strategies; What is your
> > > suggestion? 
> > > sysfs? exception event? or?
> > > 
> > > Thanks
> > > Huan
> > 
> > hey Huan,
> > 
> > What specific scenarios would require enabling a sysfs node to
> > control this function? Dynamically
> > adjusting the WriteBooster (WB) size on the fly doesn’t seem ideal
> > to me. From my perspective, the main
> > case for this feature is if the OEM didn’t correctly define or set
> > the WriteBooster Buffer size during
> > manufacturing. Even then, adjusting the WB buffer size wouldn’t be
> > a frequent need. If JEDEC has
> > found a reason for this feature to be accepted, isn’t there already
> > an interface available to configure it?
> > Why would we need a duplicate interface for the same purpose?
> > 
> > Kind regards,
> > Bean
> 
> Hi Bean,
> 
> Thanks for your reply
> 
> The scenario I'm thinking of right now： when the old phone transfers
> a large
> amount of data to the new phone's APP (vivo calls it easyshare APP),
> we can 
> explicitly resize the WB buffer.
> Could you please explain this sentence(If JEDEC has found a reason
> for this feature
> to be accepted, isn’t there already an interface available to
> configure it? Why
> would we need a duplicate interface for the same purpose?) more
> simply so I 
> can understand it better?


I see, easyshare is a case, but we have interface which allows user to
configure UFS attributes, such as ufs-bsg, you can use this interface
to achieve this in your application easily, right?


Kind regares,
Bean

Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bart Van Assche]

On 10/29/24 6:18 AM, Bean Huo wrote:
> I see, easyshare is a case, but we have interface which allows user to
> configure UFS attributes, such as ufs-bsg, you can use this interface
> to achieve this in your application easily, right?

ufs-bsg should not be suggested as an alternative for a sysfs interface
since the bsg interface bypasses a significant amount of logic in the
UFS core driver (clock scaling, clock gating, ...).

Thanks,

Bart.

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

> -----Original Message-----
> From: Bart Van Assche <bvanassche@acm.org>
> Sent: Dienstag, 29. Oktober 2024 17:57
> To: Bean Huo <huobean@gmail.com>; Huan Tang <tanghuan@vivo.com>
> Cc: Bean Huo <beanhuo@micron.com>; cang@qti.qualcomm.com; linux-
> scsi@vger.kernel.org; opensource.kernel@vivo.com; richardp@quicinc.com;
> luhongfei@vivo.com
> Subject: Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support
> 
> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless you
> recognize the sender and were expecting this message.
> 
> 
> On 10/29/24 6:18 AM, Bean Huo wrote:
> > I see, easyshare is a case, but we have interface which allows user to
> > configure UFS attributes, such as ufs-bsg, you can use this interface
> > to achieve this in your application easily, right?
> 
> ufs-bsg should not be suggested as an alternative for a sysfs interface since the
> bsg interface bypasses a significant amount of logic in the UFS core driver
> (clock scaling, clock gating, ...).
> 
> Thanks,
> 
> Bart.


Hi Bart,

Thank you for your feedback. That's good point. But I didn't observe the ufs-bsg path bypassing core logic such as clock scaling and clock gating. However, I might be mistaken. 

From my understanding, changing certain attributes can indeed bypass the UFS driver tracking. But in this particular patch, there is no parameter or flag associated that is tracked by the UFS driver.

Best regards,
Bean

RE: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Huan Tang]

> Hi Bart,
> 
> Thank you for your feedback. That's good point. But I didn't observe the ufs-bsg path bypassing core logic such as clock scaling and clock gating. However, I might be mistaken. 
> 
> From my understanding, changing certain attributes can indeed bypass the UFS driver tracking. But in this particular patch, there is no parameter or flag associated that is tracked by the UFS driver.
> 
> Best regards,
> Bean

Hi Bean,

Thank you for your reply!

Actually, there are some parameters related to UFS driver; for example: b_presrv_uspc_en, host_sem, etc.

Thanks
Huan

Re: [EXT] Re: [PATCH v2] ufs: core: Add WB buffer resize support

[Bean Huo]

On Wed, 2024-10-30 at 17:37 +0800, Huan Tang wrote:
> > Hi Bart,
> > 
> > Thank you for your feedback. That's good point. But I didn't
> > observe the ufs-bsg path bypassing core logic such as clock scaling
> > and clock gating. However, I might be mistaken. 
> > 
> > From my understanding, changing certain attributes can indeed
> > bypass the UFS driver tracking. But in this particular patch, there
> > is no parameter or flag associated that is tracked by the UFS
> > driver.
> > 
> > Best regards,
> > Bean
> 
> Hi Bean,
> 
> Thank you for your reply!
> 
> Actually, there are some parameters related to UFS driver; for
> example: b_presrv_uspc_en, host_sem, etc.
> 
> Thanks
> Huan


I meant there isn’t a UFS driver parameter tied to adjusting the WB size. 
If you think there is issue on changing WB size over ufs-bsg, please
make sure
to emphasize the issue of this and the reason why you add this new
interface in
your patch.


Kind regards,
Bean