Documentation/ABI/testing/sysfs-driver-ufs | 86 +++++++ drivers/ufs/core/ufs-sysfs.c | 258 ++++++++++++++++----- include/ufs/ufs.h | 9 + 3 files changed, 290 insertions(+), 63 deletions(-)
Expose the following JEDEC UFS 4.1 Extended WriteBooster attributes and
flags to sysfs to support FIFO and Pinned partial flush modes:
- wb_partial_flush_mode
- wb_max_fifo_size
- wb_cur_fifo_size
- wb_pinned_cur_size
- wb_pinned_avail_pct
- wb_pinned_cumulative_write_size
- wb_pinned_size
- wb_non_pinned_min_size
- wb_unpin_enable
Introduce UFS_ATTRIBUTE_RW and UFS_FLAG_RW to support writable attributes
and flags.
Document the new entries under Documentation/ABI/testing/sysfs-driver-ufs.
Assisted-by: Gemini:gemini-3.1
Signed-off-by: Daniel Lee <chullee@google.com>
---
Documentation/ABI/testing/sysfs-driver-ufs | 86 +++++++
drivers/ufs/core/ufs-sysfs.c | 258 ++++++++++++++++-----
include/ufs/ufs.h | 9 +
3 files changed, 290 insertions(+), 63 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index 3c422aac778b..d295c0923e2e 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1791,3 +1791,89 @@ Description:
will be rejected.
The attribute is read/write.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_partial_flush_mode
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_partial_flush_mode
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry controls Extended WriteBooster partial flush modes.
+
+ ====== ==============================
+ 0 No partial flush
+ 1 FIFO (first-in-first-out) mode
+ 2 Pinned mode
+ Others Reserved
+ ====== ==============================
+
+ The attribute is read-write.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_max_fifo_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_max_fifo_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry configures the maximum size in Allocation Units reserved for the
+ WriteBooster FIFO Buffer size.
+ The attribute is read-write.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_cur_fifo_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_cur_fifo_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry shows the current size in Allocation Units of the WriteBooster FIFO
+ Buffer size.
+ The attribute is read only.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_pinned_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_pinned_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry configures the allocated size in Allocation Units for the UFS
+ Pinned WriteBooster buffer.
+ The attribute is read-write.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_pinned_cur_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_pinned_cur_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry shows the current allocated size in Allocation Units for the UFS
+ Pinned WriteBooster buffer.
+ The attribute is read-only.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_pinned_avail_pct
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_pinned_avail_pct
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry shows the percentage of available space remaining in the
+ Pinned WriteBooster buffer.
+ The attribute is read-only.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_pinned_cumulative_write_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_pinned_cumulative_write_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry shows the total cumulative size of data written to the
+ Pinned WriteBooster buffer.
+ The attribute is read-only.
+
+What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_non_pinned_min_size
+What: /sys/bus/platform/devices/*.ufs/attributes/wb_non_pinned_min_size
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry configures the minimum size in Allocation Units for the
+ Non-Pinned WriteBooster Buffer area when Pinned partial flush mode is active.
+ The attribute is read-write.
+
+What: /sys/bus/platform/drivers/ufshcd/*/flags/wb_unpin_enable
+What: /sys/bus/platform/devices/*.ufs/flags/wb_unpin_enable
+Date: June 2026
+Contact: Daniel Lee <chullee@google.com>
+Description: This entry controls the Pinned WriteBooster unpin enable flag (fUnpinEn).
+
+ ====== ==============================================================
+ 0 Unpin Disable: pinned data is not flushed by WriteBooster
+ Buffer flush operation.
+ 1 Unpin Enable: pinned data is flushed by WriteBooster
+ Buffer flush operation.
+ ====== ==============================================================
+
+ The attribute is read-write.
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index d9dc4cc3452e..b981fbeda192 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -1527,41 +1527,98 @@ static const struct attribute_group ufs_sysfs_string_descriptors_group = {
static inline bool ufshcd_is_wb_flags(enum flag_idn idn)
{
- return idn >= QUERY_FLAG_IDN_WB_EN &&
- idn <= QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8;
+ return (idn >= QUERY_FLAG_IDN_WB_EN &&
+ idn <= QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8) ||
+ idn == QUERY_FLAG_IDN_WB_UNPIN_EN;
+}
+
+static ssize_t ufs_sysfs_flag_show(struct device *dev,
+ struct device_attribute *attr, char *buf, enum flag_idn idn)
+{
+ bool flag;
+ u8 index = 0;
+ int ret;
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ up(&hba->host_sem);
+ return -EBUSY;
+ }
+ if (ufshcd_is_wb_flags(idn))
+ index = ufshcd_wb_get_query_index(hba);
+ ufshcd_rpm_get_sync(hba);
+ ret = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,
+ idn, index, &flag);
+ ufshcd_rpm_put_sync(hba);
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = sysfs_emit(buf, "%s\n", str_true_false(flag));
+out:
+ up(&hba->host_sem);
+ return ret;
+}
+
+static ssize_t ufs_sysfs_flag_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count,
+ enum flag_idn idn)
+{
+ bool value;
+ u8 index = 0;
+ int ret;
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+
+ if (kstrtobool(buf, &value))
+ return -EINVAL;
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ up(&hba->host_sem);
+ return -EBUSY;
+ }
+ if (ufshcd_is_wb_flags(idn))
+ index = ufshcd_wb_get_query_index(hba);
+ ufshcd_rpm_get_sync(hba);
+ ret = ufshcd_query_flag(hba,
+ value ? UPIU_QUERY_OPCODE_SET_FLAG : UPIU_QUERY_OPCODE_CLEAR_FLAG,
+ idn, index, NULL);
+ ufshcd_rpm_put_sync(hba);
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+out:
+ up(&hba->host_sem);
+ return ret ? ret : count;
}
#define UFS_FLAG(_name, _uname) \
static ssize_t _name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
- bool flag; \
- u8 index = 0; \
- int ret; \
- struct ufs_hba *hba = dev_get_drvdata(dev); \
- \
- down(&hba->host_sem); \
- if (!ufshcd_is_user_access_allowed(hba)) { \
- up(&hba->host_sem); \
- return -EBUSY; \
- } \
- if (ufshcd_is_wb_flags(QUERY_FLAG_IDN##_uname)) \
- index = ufshcd_wb_get_query_index(hba); \
- ufshcd_rpm_get_sync(hba); \
- ret = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG, \
- QUERY_FLAG_IDN##_uname, index, &flag); \
- ufshcd_rpm_put_sync(hba); \
- if (ret) { \
- ret = -EINVAL; \
- goto out; \
- } \
- ret = sysfs_emit(buf, "%s\n", str_true_false(flag)); \
-out: \
- up(&hba->host_sem); \
- return ret; \
+ return ufs_sysfs_flag_show(dev, attr, buf, \
+ QUERY_FLAG_IDN##_uname); \
} \
static DEVICE_ATTR_RO(_name)
+#define UFS_FLAG_RW(_name, _uname) \
+static ssize_t _name##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ return ufs_sysfs_flag_show(dev, attr, buf, \
+ QUERY_FLAG_IDN##_uname); \
+} \
+static ssize_t _name##_store(struct device *dev, \
+ struct device_attribute *attr, const char *buf, size_t count) \
+{ \
+ return ufs_sysfs_flag_store(dev, attr, buf, count, \
+ QUERY_FLAG_IDN##_uname); \
+} \
+static DEVICE_ATTR_RW(_name)
+
+
UFS_FLAG(device_init, _FDEVICEINIT);
UFS_FLAG(permanent_wpe, _PERMANENT_WPE);
UFS_FLAG(power_on_wpe, _PWR_ON_WPE);
@@ -1573,6 +1630,7 @@ UFS_FLAG(disable_fw_update, _PERMANENTLY_DISABLE_FW_UPDATE);
UFS_FLAG(wb_enable, _WB_EN);
UFS_FLAG(wb_flush_en, _WB_BUFF_FLUSH_EN);
UFS_FLAG(wb_flush_during_h8, _WB_BUFF_FLUSH_DURING_HIBERN8);
+UFS_FLAG_RW(wb_unpin_enable, _WB_UNPIN_EN);
static struct attribute *ufs_sysfs_device_flags[] = {
&dev_attr_device_init.attr,
@@ -1586,6 +1644,7 @@ static struct attribute *ufs_sysfs_device_flags[] = {
&dev_attr_wb_enable.attr,
&dev_attr_wb_flush_en.attr,
&dev_attr_wb_flush_during_h8.attr,
+ &dev_attr_wb_unpin_enable.attr,
NULL,
};
@@ -1671,10 +1730,14 @@ static DEVICE_ATTR_RW(max_number_of_rtt);
static inline bool ufshcd_is_wb_attrs(enum attr_idn idn)
{
- return idn >= QUERY_ATTR_IDN_WB_FLUSH_STATUS &&
- idn <= QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE;
+ return (idn >= QUERY_ATTR_IDN_WB_FLUSH_STATUS &&
+ idn <= QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE) ||
+ (idn >= QUERY_ATTR_IDN_WB_PFM &&
+ idn <= QUERY_ATTR_IDN_NON_PINNED_WB_MIN_SIZE);
}
+
+
static inline bool ufshcd_is_qword_attr(enum attr_idn idn)
{
return idn == QUERY_ATTR_IDN_TIMESTAMP ||
@@ -1742,48 +1805,101 @@ static ssize_t wb_resize_status_show(struct device *dev,
static DEVICE_ATTR_RO(wb_resize_status);
+static ssize_t ufs_sysfs_attr_show(struct device *dev,
+ struct device_attribute *attr, char *buf, enum attr_idn idn)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ u64 qword_value;
+ u32 value;
+ int ret;
+ u8 index = 0;
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ up(&hba->host_sem);
+ return -EBUSY;
+ }
+ if (ufshcd_is_wb_attrs(idn))
+ index = ufshcd_wb_get_query_index(hba);
+ ufshcd_rpm_get_sync(hba);
+ if (ufshcd_is_qword_attr(idn))
+ ret = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+ idn, index, 0, &qword_value);
+ else
+ ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+ idn, index, 0, &value);
+ ufshcd_rpm_put_sync(hba);
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (ufshcd_is_qword_attr(idn))
+ ret = sysfs_emit(buf, "0x%016llX\n", qword_value);
+ else
+ ret = sysfs_emit(buf, "0x%08X\n", value);
+out:
+ up(&hba->host_sem);
+ return ret;
+}
+
+static ssize_t ufs_sysfs_attr_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count,
+ enum attr_idn idn)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ u32 value;
+ int ret;
+ u8 index = 0;
+
+ if (kstrtou32(buf, 0, &value))
+ return -EINVAL;
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ up(&hba->host_sem);
+ return -EBUSY;
+ }
+ if (ufshcd_is_wb_attrs(idn))
+ index = ufshcd_wb_get_query_index(hba);
+ ufshcd_rpm_get_sync(hba);
+ ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+ idn, index, 0, &value);
+ ufshcd_rpm_put_sync(hba);
+ if (ret) {
+ ret = -EINVAL;
+ goto out;
+ }
+out:
+ up(&hba->host_sem);
+ return ret ? ret : count;
+}
+
#define UFS_ATTRIBUTE(_name, _uname) \
static ssize_t _name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
- struct ufs_hba *hba = dev_get_drvdata(dev); \
- u64 qword_value; \
- u32 value; \
- int ret; \
- u8 index = 0; \
- \
- down(&hba->host_sem); \
- if (!ufshcd_is_user_access_allowed(hba)) { \
- up(&hba->host_sem); \
- return -EBUSY; \
- } \
- if (ufshcd_is_wb_attrs(QUERY_ATTR_IDN##_uname)) \
- index = ufshcd_wb_get_query_index(hba); \
- ufshcd_rpm_get_sync(hba); \
- if (ufshcd_is_qword_attr(QUERY_ATTR_IDN##_uname)) \
- ret = ufshcd_query_attr_qword(hba, \
- UPIU_QUERY_OPCODE_READ_ATTR, \
- QUERY_ATTR_IDN##_uname, \
- index, 0, &qword_value); \
- else \
- ret = ufshcd_query_attr(hba, \
- UPIU_QUERY_OPCODE_READ_ATTR, \
- QUERY_ATTR_IDN##_uname, index, 0, &value); \
- ufshcd_rpm_put_sync(hba); \
- if (ret) { \
- ret = -EINVAL; \
- goto out; \
- } \
- if (ufshcd_is_qword_attr(QUERY_ATTR_IDN##_uname)) \
- ret = sysfs_emit(buf, "0x%016llX\n", qword_value); \
- else \
- ret = sysfs_emit(buf, "0x%08X\n", value); \
-out: \
- up(&hba->host_sem); \
- return ret; \
+ return ufs_sysfs_attr_show(dev, attr, buf, \
+ QUERY_ATTR_IDN##_uname); \
} \
static DEVICE_ATTR_RO(_name)
+#define UFS_ATTRIBUTE_RW(_name, _uname) \
+static ssize_t _name##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ return ufs_sysfs_attr_show(dev, attr, buf, \
+ QUERY_ATTR_IDN##_uname); \
+} \
+static ssize_t _name##_store(struct device *dev, \
+ struct device_attribute *attr, \
+ const char *buf, size_t count) \
+{ \
+ return ufs_sysfs_attr_store(dev, attr, buf, count, \
+ QUERY_ATTR_IDN##_uname); \
+} \
+static DEVICE_ATTR_RW(_name)
+
+
UFS_ATTRIBUTE(boot_lun_enabled, _BOOT_LU_EN);
UFS_ATTRIBUTE(current_power_mode, _POWER_MODE);
UFS_ATTRIBUTE(active_icc_level, _ACTIVE_ICC_LVL);
@@ -1803,6 +1919,14 @@ 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_RW(wb_partial_flush_mode, _WB_PFM);
+UFS_ATTRIBUTE_RW(wb_max_fifo_size, _MAX_FIFO_SIZE_WB_PFM);
+UFS_ATTRIBUTE(wb_cur_fifo_size, _CURRENT_FIFO_SIZE_WB_PFM);
+UFS_ATTRIBUTE(wb_pinned_cur_size, _PINNED_WB_CURRENT_SIZE);
+UFS_ATTRIBUTE(wb_pinned_avail_pct, _PINNED_WB_AVAIL_PERC);
+UFS_ATTRIBUTE(wb_pinned_cumulative_write_size, _PINNED_WB_CUMMULATIVE_WS);
+UFS_ATTRIBUTE_RW(wb_pinned_size, _PINNED_WB_SIZE);
+UFS_ATTRIBUTE_RW(wb_non_pinned_min_size, _NON_PINNED_WB_MIN_SIZE);
static struct attribute *ufs_sysfs_attributes[] = {
@@ -1828,6 +1952,14 @@ static struct attribute *ufs_sysfs_attributes[] = {
&dev_attr_wb_cur_buf.attr,
&dev_attr_wb_resize_hint.attr,
&dev_attr_wb_resize_status.attr,
+ &dev_attr_wb_partial_flush_mode.attr,
+ &dev_attr_wb_max_fifo_size.attr,
+ &dev_attr_wb_cur_fifo_size.attr,
+ &dev_attr_wb_pinned_cur_size.attr,
+ &dev_attr_wb_pinned_avail_pct.attr,
+ &dev_attr_wb_pinned_cumulative_write_size.attr,
+ &dev_attr_wb_pinned_size.attr,
+ &dev_attr_wb_non_pinned_min_size.attr,
NULL,
};
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 0d48e137d66d..2d9455b7cd88 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -146,6 +146,7 @@ enum flag_idn {
QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8 = 0x10,
QUERY_FLAG_IDN_HPB_RESET = 0x11,
QUERY_FLAG_IDN_HPB_EN = 0x12,
+ QUERY_FLAG_IDN_WB_UNPIN_EN = 0x13,
};
/* Attribute idn for Query requests */
@@ -191,6 +192,14 @@ enum attr_idn {
QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT = 0x3C,
QUERY_ATTR_IDN_WB_BUF_RESIZE_EN = 0x3D,
QUERY_ATTR_IDN_WB_BUF_RESIZE_STATUS = 0x3E,
+ QUERY_ATTR_IDN_WB_PFM = 0x3F,
+ QUERY_ATTR_IDN_MAX_FIFO_SIZE_WB_PFM = 0x40,
+ QUERY_ATTR_IDN_CURRENT_FIFO_SIZE_WB_PFM = 0x41,
+ QUERY_ATTR_IDN_PINNED_WB_CURRENT_SIZE = 0x42,
+ QUERY_ATTR_IDN_PINNED_WB_AVAIL_PERC = 0x43,
+ QUERY_ATTR_IDN_PINNED_WB_CUMMULATIVE_WS = 0x44,
+ QUERY_ATTR_IDN_PINNED_WB_SIZE = 0x45,
+ QUERY_ATTR_IDN_NON_PINNED_WB_MIN_SIZE = 0x46,
QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS = 0x47,
QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS_EXT = 0x48,
};
--
2.54.0.1032.g2f8565e1d1-googOn 6/5/26 2:31 AM, Daniel Lee wrote:
> +What: /sys/bus/platform/drivers/ufshcd/*/attributes/wb_partial_flush_mode
> +What: /sys/bus/platform/devices/*.ufs/attributes/wb_partial_flush_mode
> +Date: June 2026
> +Contact: Daniel Lee <chullee@google.com>
> +Description: This entry controls Extended WriteBooster partial flush modes.
> +
> + ====== ==============================
> + 0 No partial flush
> + 1 FIFO (first-in-first-out) mode
> + 2 Pinned mode
> + Others Reserved
> + ====== ==============================
> +
> + The attribute is read-write.
Please change this attribute such that it accepts and reports strings
instead of numbers. This is more user-friendly and also will make shell
scripts that read from or write into this sysfs attribute much easier to
read. This will make this attribute follow the design philosophy of
self-documenting interfaces.
> +static ssize_t ufs_sysfs_flag_show(struct device *dev,
> + struct device_attribute *attr, char *buf, enum flag_idn idn)
> +{
> + bool flag;
> + u8 index = 0;
> + int ret;
> + struct ufs_hba *hba = dev_get_drvdata(dev);
In new code, please order declarations from longest to shortest.
> +static ssize_t ufs_sysfs_flag_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count,
> + enum flag_idn idn)
> +{
> + bool value;
> + u8 index = 0;
> + int ret;
> + struct ufs_hba *hba = dev_get_drvdata(dev);
Also here, please order declarations from longest to shortest.
Thanks,
Bart.
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