RE: [PATCH v2] scsi: ufs: wb: Add Manual Flush sysfs and cleanup toggle functions

[Avri Altman]

> There is the following quirk to bypass "WB Manual Flush" in Write Booster.
> 
>         - UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
> 
> If this quirk is not set, there is no knob that can control "WB Manual Flush".
> 
> There are three flags that control Write Booster Feature.
>         1. WB ON/OFF
>         2. WB Hibern Flush ON/OFF
>         3. WB Flush ON/OFF
> 
> The sysfs that controls the WB was implemented. (1)
> 
> In the case of "Hibern Flush", it is always good to turn on.
> Control may not be required. (2)
> 
> Finally, "Manual flush" may be necessary because the Auto-Hibern8 is not
> supported in a specific environment.
> So the sysfs that controls this is necessary. (3)
> 
> In addition, toggle functions for controlling the above flags are cleaned.
This patch should be divided into min 2 patches, probably 3:
One is all the renaming & cleanups - no functional change.
And the other is adding the sysfs entry.

Thanks,
Avri

> 
> V2:
>         - modify commit message
>         - move & modify err messages
>         - remove unnesscessary debug messages
> 
> Signed-off-by: Jinyoung Choi <j-young.choi@xxxxxxxxxxx>
> ---
>  drivers/ufs/core/ufs-sysfs.c | 46 +++++++++++++++++++++++-
>  drivers/ufs/core/ufshcd.c    | 69 +++++++++++++++++-------------------
>  include/ufs/ufshcd.h         |  7 ++++
>  3 files changed, 84 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
> index 0a088b47d557..b1c51d8df9f4 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -230,7 +230,7 @@ static ssize_t wb_on_store(struct device *dev, struct
> device_attribute *attr,
>                  * 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");
> +               dev_warn(dev, "It is not allowed to control WB!\n");
>                 return -EOPNOTSUPP;
>         }
> 
> @@ -254,6 +254,48 @@ static ssize_t wb_on_store(struct device *dev, struct
> device_attribute *attr,
>         return res < 0 ? res : count;
>  }
> 
> +static ssize_t wb_buf_flush_en_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->dev_info.wb_buf_flush_enabled);
> +}
> +
> +static ssize_t wb_buf_flush_en_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_flush_en;
> +       ssize_t res;
> +
> +       if (!ufshcd_is_wb_buf_flush_allowed(hba)) {
> +               dev_warn(dev, "It is not allowed to control WB buf flush!\n");
> +               return -EOPNOTSUPP;
> +       }
> +
> +       if (kstrtouint(buf, 0, &wb_buf_flush_en))
> +               return -EINVAL;
> +
> +       if (wb_buf_flush_en != 0 && wb_buf_flush_en != 1)
> +               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_toggle_buf_flush(hba, wb_buf_flush_en);
> +       ufshcd_rpm_put_sync(hba);
> +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);
> @@ -262,6 +304,7 @@ 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 DEVICE_ATTR_RW(wb_buf_flush_en);
> 
>  static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
>         &dev_attr_rpm_lvl.attr,
> @@ -272,6 +315,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
>         &dev_attr_spm_target_link_state.attr,
>         &dev_attr_auto_hibern8.attr,
>         &dev_attr_wb_on.attr,
> +       &dev_attr_wb_buf_flush_en.attr,
>         NULL
>  };
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index f5d5dde497ac..439f6cb15084 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -268,8 +268,7 @@ static int ufshcd_setup_vreg(struct ufs_hba *hba,
> bool on);
>  static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
>                                          struct ufs_vreg *vreg);
>  static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag);
> -static void 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_wb_toggle_buf_flush_during_h8(struct ufs_hba *hba,
> bool set);
>  static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
>  static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba);
> 
> @@ -289,16 +288,16 @@ static inline void ufshcd_disable_irq(struct ufs_hba
> *hba)
>         }
>  }
> 
> -static inline void ufshcd_wb_config(struct ufs_hba *hba)
> +static void ufshcd_wb_set_default_flags(struct ufs_hba *hba)
>  {
>         if (!ufshcd_is_wb_allowed(hba))
>                 return;
> 
>         ufshcd_wb_toggle(hba, true);
> +       ufshcd_wb_toggle_buf_flush_during_h8(hba, true);
> 
> -       ufshcd_wb_toggle_flush_during_h8(hba, true);
> -       if (!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL))
> -               ufshcd_wb_toggle_flush(hba, true);
> +       if (ufshcd_is_wb_buf_flush_allowed(hba))
> +               ufshcd_wb_toggle_buf_flush(hba, true);
>  }
> 
>  static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
> @@ -1289,9 +1288,10 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
>                 }
>         }
> 
> -       /* Enable Write Booster if we have scaled up else disable it */
>         downgrade_write(&hba->clk_scaling_lock);
>         is_writelock = false;
> +
> +       /* Enable Write Booster if we have scaled up else disable it */
>         ufshcd_wb_toggle(hba, scale_up);
> 
>  out_unprepare:
> @@ -5714,6 +5714,9 @@ static int __ufshcd_wb_toggle(struct ufs_hba *hba,
> bool set, enum flag_idn idn)
>         enum query_opcode opcode = set ? UPIU_QUERY_OPCODE_SET_FLAG :
>                                    UPIU_QUERY_OPCODE_CLEAR_FLAG;
> 
> +       if (!ufshcd_is_wb_allowed(hba))
> +               return -EPERM;
> +
>         index = ufshcd_wb_get_query_index(hba);
>         return ufshcd_query_flag_retry(hba, opcode, idn, index, NULL);
>  }
> @@ -5722,60 +5725,50 @@ int ufshcd_wb_toggle(struct ufs_hba *hba, bool
> enable)
>  {
>         int ret;
> 
> -       if (!ufshcd_is_wb_allowed(hba))
> -               return 0;
> -
> -       if (!(enable ^ hba->dev_info.wb_enabled))
> +       if (hba->dev_info.wb_enabled == enable)
>                 return 0;
> 
>         ret = __ufshcd_wb_toggle(hba, enable, QUERY_FLAG_IDN_WB_EN);
>         if (ret) {
> -               dev_err(hba->dev, "%s Write Booster %s failed %d\n",
> +               dev_err(hba->dev, "%s: failed to %s WB %d\n",
>                         __func__, enable ? "enable" : "disable", ret);
>                 return ret;
>         }
> 
>         hba->dev_info.wb_enabled = enable;
> -       dev_info(hba->dev, "%s Write Booster %s\n",
> -                       __func__, enable ? "enabled" : "disabled");
> 
>         return ret;
>  }
> 
> -static void ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool
> set)
> +static void ufshcd_wb_toggle_buf_flush_during_h8(struct ufs_hba *hba,
> +                                                bool enable)
>  {
>         int ret;
> 
> -       ret = __ufshcd_wb_toggle(hba, set,
> -                       QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8);
> -       if (ret) {
> -               dev_err(hba->dev, "%s: WB-Buf Flush during H8 %s failed: %d\n",
> -                       __func__, set ? "enable" : "disable", ret);
> -               return;
> -       }
> -       dev_dbg(hba->dev, "%s WB-Buf Flush during H8 %s\n",
> -                       __func__, set ? "enabled" : "disabled");
> +       ret = __ufshcd_wb_toggle(hba, enable,
> +                                QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8);
> +       if (ret)
> +               dev_err(hba->dev, "%s: failed to %s WB buf flush during H8 %d\n",
> +                       __func__, enable ? "enable" : "disable", ret);
>  }
> 
> -static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable)
> +int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable)
>  {
>         int ret;
> 
> -       if (!ufshcd_is_wb_allowed(hba) ||
> -           hba->dev_info.wb_buf_flush_enabled == enable)
> -               return;
> +       if (hba->dev_info.wb_buf_flush_enabled == enable)
> +               return 0;
> 
>         ret = __ufshcd_wb_toggle(hba, enable,
> QUERY_FLAG_IDN_WB_BUFF_FLUSH_EN);
>         if (ret) {
> -               dev_err(hba->dev, "%s WB-Buf Flush %s failed %d\n", __func__,
> -                       enable ? "enable" : "disable", ret);
> -               return;
> +               dev_err(hba->dev, "%s: failed to %s WB buf flush %d\n",
> +                       __func__, enable ? "enable" : "disable", ret);
> +               return ret;
>         }
> 
>         hba->dev_info.wb_buf_flush_enabled = enable;
> 
> -       dev_dbg(hba->dev, "%s WB-Buf Flush %s\n",
> -                       __func__, enable ? "enabled" : "disabled");
> +       return ret;
>  }
> 
>  static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
> @@ -5806,10 +5799,10 @@ static bool
> ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
> 
>  static void ufshcd_wb_force_disable(struct ufs_hba *hba)
>  {
> -       if (!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL))
> -               ufshcd_wb_toggle_flush(hba, false);
> +       if (ufshcd_is_wb_buf_flush_allowed(hba))
> +               ufshcd_wb_toggle_buf_flush(hba, false);
> 
> -       ufshcd_wb_toggle_flush_during_h8(hba, false);
> +       ufshcd_wb_toggle_buf_flush_during_h8(hba, false);
>         ufshcd_wb_toggle(hba, false);
>         hba->caps &= ~UFSHCD_CAP_WB_EN;
> 
> @@ -8195,7 +8188,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba,
> bool init_dev_params)
>          */
>         ufshcd_set_active_icc_lvl(hba);
> 
> -       ufshcd_wb_config(hba);
> +       /* Enable UFS Write Booster if supported */
> +       ufshcd_wb_set_default_flags(hba);
> +
>         if (hba->ee_usr_mask)
>                 ufshcd_write_ee_control(hba);
>         /* Enable Auto-Hibernate if configured */
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index b5c9064a11d9..8c9461d45606 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -1017,6 +1017,12 @@ static inline bool ufshcd_is_wb_allowed(struct
> ufs_hba *hba)
>         return hba->caps & UFSHCD_CAP_WB_EN;
>  }
> 
> +static inline bool ufshcd_is_wb_buf_flush_allowed(struct ufs_hba *hba)
> +{
> +       return ufshcd_is_wb_allowed(hba) &&
> +               !(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL);
> +}
> +
>  #define ufshcd_writel(hba, val, reg)   \
>         writel((val), (hba)->mmio_base + (reg))
>  #define ufshcd_readl(hba, reg) \
> @@ -1211,6 +1217,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba
> *hba,
>                              enum query_opcode desc_op);
> 
>  int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
> +int ufshcd_wb_toggle_buf_flush(struct ufs_hba *hba, bool enable);
>  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);
> --
> 2.25.1