[PATCH v8] ufs: core: Add WB buffer resize support

[PATCH v8] ufs: core: Add WB buffer resize support

[Huan Tang]

Follow JESD220G, 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_resize_enable
	2. wb_resize_hint
	3. wb_resize_status
The detailed definition of the three nodes can be found in the sysfs
documentation.

Changelog
===
v7 - > v8:
	1.Optimized the description in the sysfs-driver-ufs file
	2.Replace uppercase with lowercase, for example: "KEEP" -> "keep"
	3.Fix coding style issues with switch/case statements
 
v6 - > v7:
	1.Use "xxxx_to_string" for string convert
	2.Use uppercase characters, for example: "keep" -> "KEEP"
	3.Resize enable mode support "IDLE"

v5 - > v6:
	1.Fix mistake: obtain the return value of "sysfs_emit"

v4 - > v5:
	1.For the three new attributes: use words in sysfs instead of numbers

v3 - > v4:
	1.modify three attributes name and description in document
	2.add enum wb_resize_en in ufs.h
	3.modify function name and parameters in ufs-sysfs.c, ufshcd.h, ufshcd.c

v2 - > v3:
	Remove needless code:
	drivers/ufs/core/ufs-sysfs.c:441:2:
	index =	ufshcd_wb_get_query_index(hba)

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/
v2
	https://lore.kernel.org/all/20241026004423.135-1-tanghuan@vivo.com/
v3
	https://lore.kernel.org/all/20241028135205.188-1-tanghuan@vivo.com/
v4
	https://lore.kernel.org/all/20241101093318.825-1-tanghuan@vivo.com/
v5
	https://lore.kernel.org/all/20241104134612.178-1-tanghuan@vivo.com/
v6
	https://lore.kernel.org/all/20241104142437.234-1-tanghuan@vivo.com/
v7
	https://lore.kernel.org/all/20250402014536.162-1-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 |  49 ++++++++
 drivers/ufs/core/ufs-sysfs.c               | 140 +++++++++++++++++++++
 drivers/ufs/core/ufshcd.c                  |  15 +++
 include/ufs/ufs.h                          |  27 +++-
 include/ufs/ufshcd.h                       |   1 +
 5 files changed, 231 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index ae0191295d29..bddcf48910ed 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1604,3 +1604,52 @@ Description:
 		prevent the UFS from frequently performing clock gating/ungating.
 
 		The attribute is read/write.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/wb_resize_enable
+What:		/sys/bus/platform/devices/*.ufs/wb_resize_enable
+Date:		April 2025
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		The host can enable the WriteBooster buffer resize by setting this
+		attribute.
+
+		========  ======================================
+		idle      There is no resize operation
+		decrease  Decrease WriteBooster buffer size
+		increase  Increase WriteBooster buffer size
+		========  ======================================
+
+		The attribute is write only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/attributes/wb_resize_hint
+What:		/sys/bus/platform/devices/*.ufs/attributes/wb_resize_hint
+Date:		April 2025
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		wb_resize_hint indicates hint information about which type of resize
+		for	WriteBooster buffer is recommended by the device.
+
+		=========  ======================================
+		keep       Recommend keep the buffer size
+		decrease   Recommend to decrease the buffer size
+		increase   Recommend to increase the buffer size
+		=========  ======================================
+
+		The attribute is read only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/attributes/wb_resize_status
+What:		/sys/bus/platform/devices/*.ufs/attributes/wb_resize_status
+Date:		April 2025
+Contact:	Huan Tang <tanghuan@vivo.com>
+Description:
+		The host can check the resize operation status of the WriteBooster
+		buffer by reading this attribute.
+
+		================  ========================================
+		idle              Resize operation is not issued
+		in_progress       Resize operation in progress
+		complete_success  Resize operation completed successfully
+		gerneral_fail     Resize operation general failure
+		================  ========================================
+
+		The attribute is read only.
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 90b5ab60f5ae..9767fd719243 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -57,6 +57,36 @@ static const char *ufs_hs_gear_to_string(enum ufs_hs_gear_tag gear)
 	}
 }
 
+static const char *ufs_wb_resize_hint_to_string(enum wb_resize_hint hint)
+{
+	switch (hint) {
+	case WB_RESIZE_HINT_KEEP:
+		return "keep";
+	case WB_RESIZE_HINT_DECREASE:
+		return "decrease";
+	case WB_RESIZE_HINT_INCREASE:
+		return "increase";
+	default:
+		return "unknown";
+	}
+}
+
+static const char *ufs_wb_resize_status_to_string(enum wb_resize_status status)
+{
+	switch (status) {
+	case WB_RESIZE_STATUS_IDLE:
+		return "idle";
+	case WB_RESIZE_STATUS_IN_PROGRESS:
+		return "in_progress";
+	case WB_RESIZE_STATUS_COMPLETE_SUCCESS:
+		return "complete_success";
+	case WB_RESIZE_STATUS_GENERAL_FAIL:
+		return "gerneral_fail";
+	default:
+		return "unknown";
+	}
+}
+
 static const char *ufshcd_uic_link_state_to_string(
 			enum uic_link_state state)
 {
@@ -411,6 +441,43 @@ static ssize_t wb_flush_threshold_store(struct device *dev,
 	return count;
 }
 
+static const char * const wb_resize_en_mode[] = {
+	[WB_RESIZE_EN_IDLE]		= "idle",
+	[WB_RESIZE_EN_DECREASE]		= "decrease",
+	[WB_RESIZE_EN_INCREASE]		= "increase",
+};
+
+static ssize_t wb_resize_enable_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int mode;
+	ssize_t res;
+
+	if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled ||
+		!hba->dev_info.b_presrv_uspc_en)
+		return -EOPNOTSUPP;
+
+	mode = sysfs_match_string(wb_resize_en_mode, buf);
+	if (mode < 0)
+		return -EINVAL;
+
+	down(&hba->host_sem);
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		res = -EBUSY;
+		goto out;
+	}
+
+	ufshcd_rpm_get_sync(hba);
+	res = ufshcd_wb_set_resize_en(hba, (u32)mode);
+	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
@@ -476,6 +543,7 @@ 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_resize_enable);
 static DEVICE_ATTR_RW(rtc_update_ms);
 static DEVICE_ATTR_RW(pm_qos_enable);
 static DEVICE_ATTR_RO(critical_health);
@@ -491,6 +559,7 @@ 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_resize_enable.attr,
 	&dev_attr_rtc_update_ms.attr,
 	&dev_attr_pm_qos_enable.attr,
 	&dev_attr_critical_health.attr,
@@ -1495,6 +1564,75 @@ static inline bool ufshcd_is_wb_attrs(enum attr_idn idn)
 		idn <= QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE;
 }
 
+static int wb_read_resize_attrs(struct ufs_hba *hba,
+			enum attr_idn idn, u32 *attr_val)
+{
+	u8 index = 0;
+	int ret;
+
+	if (!ufshcd_is_wb_allowed(hba) || !hba->dev_info.wb_enabled ||
+		!hba->dev_info.b_presrv_uspc_en)
+		return -EOPNOTSUPP;
+
+	down(&hba->host_sem);
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	index = ufshcd_wb_get_query_index(hba);
+	ufshcd_rpm_get_sync(hba);
+	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+			idn, index, 0, attr_val);
+	ufshcd_rpm_put_sync(hba);
+	if (ret)
+		ret = -EINVAL;
+
+out:
+	up(&hba->host_sem);
+	return ret;
+}
+
+static ssize_t wb_resize_hint_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int ret;
+	u32 value;
+
+	ret = wb_read_resize_attrs(hba,
+			QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT, &value);
+	if (ret)
+		goto out;
+
+	ret = sysfs_emit(buf, "%s\n", ufs_wb_resize_hint_to_string(value));
+
+out:
+	return ret;
+}
+
+static DEVICE_ATTR_RO(wb_resize_hint);
+
+static ssize_t wb_resize_status_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int ret;
+	u32 value;
+
+	ret = wb_read_resize_attrs(hba,
+			QUERY_ATTR_IDN_WB_BUF_RESIZE_STATUS, &value);
+	if (ret)
+		goto out;
+
+	ret = sysfs_emit(buf, "%s\n", ufs_wb_resize_status_to_string(value));
+
+out:
+	return ret;
+}
+
+static DEVICE_ATTR_RO(wb_resize_status);
+
 #define UFS_ATTRIBUTE(_name, _uname)					\
 static ssize_t _name##_show(struct device *dev,				\
 	struct device_attribute *attr, char *buf)			\
@@ -1568,6 +1706,8 @@ 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_resize_hint.attr,
+	&dev_attr_wb_resize_status.attr,
 	NULL,
 };
 
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 83b092cbb864..2c52a654a1f7 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6068,6 +6068,21 @@ int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable)
 	return ret;
 }
 
+int ufshcd_wb_set_resize_en(struct ufs_hba *hba, u32 en_mode)
+{
+	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, &en_mode);
+	if (ret)
+		dev_err(hba->dev, "%s: Enable WB buf resize operation failed %d\n",
+			__func__, ret);
+
+	return ret;
+}
+
 static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
 						u32 avail_buf)
 {
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 8a24ed59ec46..ed971480c329 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -180,7 +180,10 @@ enum attr_idn {
 	QUERY_ATTR_IDN_AVAIL_WB_BUFF_SIZE       = 0x1D,
 	QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
 	QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE        = 0x1F,
-	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 */
@@ -454,6 +457,28 @@ enum ufs_ref_clk_freq {
 	REF_CLK_FREQ_INVAL	= -1,
 };
 
+/* bWriteBoosterBufferResizeEn attribute */
+enum wb_resize_en {
+	WB_RESIZE_EN_IDLE	= 0,
+	WB_RESIZE_EN_DECREASE	= 1,
+	WB_RESIZE_EN_INCREASE	= 2,
+};
+
+/* bWriteBoosterBufferResizeHint attribute */
+enum wb_resize_hint {
+	WB_RESIZE_HINT_KEEP	= 0,
+	WB_RESIZE_HINT_DECREASE	= 1,
+	WB_RESIZE_HINT_INCREASE	= 2,
+};
+
+/* bWriteBoosterBufferResizeStatus attribute */
+enum wb_resize_status {
+	WB_RESIZE_STATUS_IDLE	           = 0,
+	WB_RESIZE_STATUS_IN_PROGRESS       = 1,
+	WB_RESIZE_STATUS_COMPLETE_SUCCESS  = 2,
+	WB_RESIZE_STATUS_GENERAL_FAIL      = 3,
+};
+
 /* Query response result code */
 enum {
 	QUERY_RESULT_SUCCESS                    = 0x00,
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index f56050ce9445..74086a6cb53f 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1471,6 +1471,7 @@ 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_set_resize_en(struct ufs_hba *hba, u32 en_mode);
 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 v8] ufs: core: Add WB buffer resize support

[Bean Huo]

On Wed, 2025-04-02 at 15:57 +0800, Huan Tang wrote:
> +static const char *ufs_wb_resize_status_to_string(enum
> wb_resize_status status)
> +{
> +       switch (status) {
> +       case WB_RESIZE_STATUS_IDLE:
> +               return "idle";
> +       case WB_RESIZE_STATUS_IN_PROGRESS:
> +               return "in_progress";
> +       case WB_RESIZE_STATUS_COMPLETE_SUCCESS:
> +               return "complete_success";
> +       case WB_RESIZE_STATUS_GENERAL_FAIL:
> +               return "gerneral_fail";


Typo: "gerneral_fail"  --> general_fail

Re: [PATCH v8] ufs: core: Add WB buffer resize support

[Bean Huo]

On Wed, 2025-04-02 at 15:57 +0800, Huan Tang wrote:
>  
> +int ufshcd_wb_set_resize_en(struct ufs_hba *hba, u32 en_mode)


you must ensure the mode en_mode is within valid range (0-2), why not
use enum?


> +{
> +       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, &en_mode);
> +       if (ret)
> +               dev_err(hba->dev, "%s: Enable WB buf resize operation
> failed %d\n",
> +                       __func__, ret);
> +
> +       return ret;
> +}

Re: [PATCH v8] ufs: core: Add WB buffer resize support

[Huan Tang]

> you must ensure the mode en_mode is within valid range (0-2), why not
> use enum?
> 
> 
> > +{
> > +       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, &en_mode);
> > +       if (ret)
> > +               dev_err(hba->dev, "%s: Enable WB buf resize operation
> > failed %d\n",
> > +                       __func__, ret);
> > +
> > +       return ret;
> > +

Bean sir,

Thanks for you reply! 
Is the patch below okay?
https://lore.kernel.org/all/20250407085143.173-1-tanghuan@vivo.com/

Re: [PATCH v8] ufs: core: Add WB buffer resize support

[Huan Tang]

> Typo: "gerneral_fail"  --> general_fail

Bean sir,

Thanks for you reply! 
fix done,please review:
https://lore.kernel.org/all/20250407085143.173-1-tanghuan@vivo.com/