Commit 8e834ca5 authored by Bean Huo's avatar Bean Huo Committed by Martin K. Petersen
Browse files

scsi: ufs: Add "wb_on" sysfs node to control WB on/off 

Currently UFS WriteBooster driver uses clock scaling up/down to set WB
on/off. For the platforms which don't support UFSHCD_CAP_CLK_SCALING, WB
will be always on. Provide a sysfs attribute to enable/disable WB during
runtime. Write 1/0 to "wb_on" sysfs node to enable/disable UFS WB.

Link: https://lore.kernel.org/r/20210119163847.20165-2-huobean@gmail.com


Reviewed-by: default avatarAvri Altman <avri.altman@wdc.com>
Reviewed-by: default avatarStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: default avatarBean Huo <beanhuo@micron.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent f1ef9047

drivers/scsi/ufs/ufs-sysfs.c

+46 −0
Original line number Diff line number Diff line
@@ -209,6 +209,50 @@ static ssize_t auto_hibern8_store(struct device *dev, 
	return ret ? ret : count;

}



static ssize_t wb_on_show(struct device *dev, struct device_attribute *attr,

			  char *buf)

{

	struct ufs_hba *hba = dev_get_drvdata(dev);



	return sysfs_emit(buf, "%d\n", hba->wb_enabled);

}



static ssize_t wb_on_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_enable;

	ssize_t res;



	if (!ufshcd_is_wb_allowed(hba) || ufshcd_is_clkscaling_supported(hba)) {

		/*

		 * If the platform supports UFSHCD_CAP_CLK_SCALING, turn WB

		 * on/off will be done while clock scaling up/down.

		 */

		dev_warn(dev, "To control WB through wb_on is not allowed!\n");

		return -EOPNOTSUPP;

	}



	if (kstrtouint(buf, 0, &wb_enable))

		return -EINVAL;



	if (wb_enable != 0 && wb_enable != 1)

		return -EINVAL;



	down(&hba->host_sem);

	if (!ufshcd_is_user_access_allowed(hba)) {

		res = -EBUSY;

		goto out;

	}



	pm_runtime_get_sync(hba->dev);

	res = ufshcd_wb_ctrl(hba, wb_enable);

	pm_runtime_put_sync(hba->dev);

out:

	up(&hba->host_sem);

	return res < 0 ? res : count;

}



static DEVICE_ATTR_RW(rpm_lvl);

static DEVICE_ATTR_RO(rpm_target_dev_state);

static DEVICE_ATTR_RO(rpm_target_link_state);
@@ -216,6 +260,7 @@ static DEVICE_ATTR_RW(spm_lvl); 
static DEVICE_ATTR_RO(spm_target_dev_state);

static DEVICE_ATTR_RO(spm_target_link_state);

static DEVICE_ATTR_RW(auto_hibern8);

static DEVICE_ATTR_RW(wb_on);



static struct attribute *ufs_sysfs_ufshcd_attrs[] = {

	&dev_attr_rpm_lvl.attr,
@@ -225,6 +270,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = { 
	&dev_attr_spm_target_dev_state.attr,

	&dev_attr_spm_target_link_state.attr,

	&dev_attr_auto_hibern8.attr,

	&dev_attr_wb_on.attr,

	NULL

};

drivers/scsi/ufs/ufshcd.c

+1 −2
Original line number Diff line number Diff line
@@ -249,7 +249,6 @@ static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba, 
static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag);

static int ufshcd_wb_buf_flush_enable(struct ufs_hba *hba);

static int ufshcd_wb_buf_flush_disable(struct ufs_hba *hba);

static int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);

static int ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set);

static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable);

static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
@@ -5416,7 +5415,7 @@ static void ufshcd_bkops_exception_event_handler(struct ufs_hba *hba) 
				__func__, err);

}



static int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable)

int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable)

{

	int ret;

	u8 index;

drivers/scsi/ufs/ufshcd.h

+2 −0
Original line number Diff line number Diff line
@@ -1093,6 +1093,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba, 
			     u8 *desc_buff, int *buff_len,

			     enum query_opcode desc_op);



int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);



/* Wrapper functions for safely calling variant operations */

static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)

{