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Date:   Wed, 24 Mar 2021 13:01:49 +0800
From:   Can Guo <cang@codeaurora.org>
To:     daejun7.park@samsung.com
Cc:     Greg KH <gregkh@linuxfoundation.org>, avri.altman@wdc.com,
        jejb@linux.ibm.com, martin.petersen@oracle.com,
        asutoshd@codeaurora.org, stanley.chu@mediatek.com,
        bvanassche@acm.org, huobean@gmail.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        ALIM AKHTAR <alim.akhtar@samsung.com>,
        JinHwan Park <jh.i.park@samsung.com>,
        Javier Gonzalez <javier.gonz@samsung.com>,
        Sung-Jun Park <sungjun07.park@samsung.com>,
        Jinyoung CHOI <j-young.choi@samsung.com>,
        Dukhyun Kwon <d_hyun.kwon@samsung.com>,
        Keoseong Park <keosung.park@samsung.com>,
        Jaemyung Lee <jaemyung.lee@samsung.com>,
        Jieon Seol <jieon.seol@samsung.com>
Subject: Re: [PATCH v31 4/4] scsi: ufs: Add HPB 2.0 support
In-Reply-To: <20210322065504epcms2p698791fed570484f8de2688d238dff4c6@epcms2p6>
References: <20210322065127epcms2p5021a61416a6b427c62fcaf5d8b660860@epcms2p5>
 <CGME20210322065127epcms2p5021a61416a6b427c62fcaf5d8b660860@epcms2p6>
 <20210322065504epcms2p698791fed570484f8de2688d238dff4c6@epcms2p6>
Message-ID: <d7f98f965e724e708e85535bdcc53075@codeaurora.org>
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Precedence: bulk

On 2021-03-22 14:55, Daejun Park wrote:
> This patch supports the HPB 2.0.
> 
> The HPB 2.0 supports read of varying sizes from 4KB to 512KB.
> In the case of Read (<= 32KB) is supported as single HPB read.
> In the case of Read (36KB ~ 512KB) is supported by as a combination of
> write buffer command and HPB read command to deliver more PPN.
> The write buffer commands may not be issued immediately due to busy 
> tags.
> To use HPB read more aggressively, the driver can requeue the write 
> buffer
> command. The requeue threshold is implemented as timeout and can be
> modified with requeue_timeout_ms entry in sysfs.
> 
> Signed-off-by: Daejun Park <daejun7.park@samsung.com>
> ---
>  Documentation/ABI/testing/sysfs-driver-ufs |  47 +-
>  drivers/scsi/ufs/ufs-sysfs.c               |   4 +
>  drivers/scsi/ufs/ufs.h                     |   3 +-
>  drivers/scsi/ufs/ufshcd.c                  |  25 +-
>  drivers/scsi/ufs/ufshcd.h                  |   7 +
>  drivers/scsi/ufs/ufshpb.c                  | 626 +++++++++++++++++++--
>  drivers/scsi/ufs/ufshpb.h                  |  67 ++-
>  7 files changed, 698 insertions(+), 81 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-ufs
> b/Documentation/ABI/testing/sysfs-driver-ufs
> index 528bf89fc98b..419adf450b89 100644
> --- a/Documentation/ABI/testing/sysfs-driver-ufs
> +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> @@ -1253,14 +1253,14 @@ Description:	This entry shows the number of
> HPB pinned regions assigned to
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/hit_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/hit_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of reads that changed to HPB 
> read.
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/miss_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/miss_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of reads that cannot be 
> changed to
> @@ -1268,7 +1268,7 @@ Description:	This entry shows the number of
> reads that cannot be changed to
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/rb_noti_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/rb_noti_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of response UPIUs that has
> @@ -1276,7 +1276,7 @@ Description:	This entry shows the number of
> response UPIUs that has
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/rb_active_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/rb_active_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of active sub-regions 
> recommended by
> @@ -1284,7 +1284,7 @@ Description:	This entry shows the number of
> active sub-regions recommended by
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/rb_inactive_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/rb_inactive_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of inactive regions 
> recommended by
> @@ -1292,10 +1292,45 @@ Description:	This entry shows the number of
> inactive regions recommended by
> 
>  		The file is read only.
> 
> -What:		/sys/class/scsi_device/*/device/hpb_sysfs/map_req_cnt
> +What:		/sys/class/scsi_device/*/device/hpb_stat_sysfs/map_req_cnt
>  Date:		March 2021
>  Contact:	Daejun Park <daejun7.park@samsung.com>
>  Description:	This entry shows the number of read buffer commands for
>  		activating sub-regions recommended by response UPIUs.
> 
>  		The file is read only.
> +
> +What:		/sys/class/scsi_device/*/device/hpb_param_sysfs/requeue_timeout_ms
> +Date:		March 2021
> +Contact:	Daejun Park <daejun7.park@samsung.com>
> +Description:	This entry shows the requeue timeout threshold for write 
> buffer
> +		command in ms. This value can be changed by writing proper integer 
> to
> +		this entry.
> +
> +What:		/sys/bus/platform/drivers/ufshcd/*/attributes/max_data_size_hpb_single_cmd
> +Date:		March 2021
> +Contact:	Daejun Park <daejun7.park@samsung.com>
> +Description:	This entry shows the maximum HPB data size for using 
> single HPB
> +		command.
> +
> +		===  ========
> +		00h  4KB
> +		01h  8KB
> +		02h  12KB
> +		...
> +		FFh  1024KB
> +		===  ========
> +
> +		The file is read only.
> +
> +What:		/sys/bus/platform/drivers/ufshcd/*/flags/wb_enable
> +Date:		March 2021
> +Contact:	Daejun Park <daejun7.park@samsung.com>
> +Description:	This entry shows the status of HPB.
> +
> +		== ============================
> +		0  HPB is not enabled.
> +		1  HPB is enabled
> +		== ============================
> +
> +		The file is read only.
> diff --git a/drivers/scsi/ufs/ufs-sysfs.c 
> b/drivers/scsi/ufs/ufs-sysfs.c
> index 2546e7a1ac4f..92a883866e12 100644
> --- a/drivers/scsi/ufs/ufs-sysfs.c
> +++ b/drivers/scsi/ufs/ufs-sysfs.c
> @@ -782,6 +782,7 @@ 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(hpb_enable, _HPB_EN);
> 
>  static struct attribute *ufs_sysfs_device_flags[] = {
>  	&dev_attr_device_init.attr,
> @@ -795,6 +796,7 @@ 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_hpb_enable.attr,
>  	NULL,
>  };
> 
> @@ -841,6 +843,7 @@ out:									\
>  static DEVICE_ATTR_RO(_name)
> 
>  UFS_ATTRIBUTE(boot_lun_enabled, _BOOT_LU_EN);
> +UFS_ATTRIBUTE(max_data_size_hpb_single_cmd, _MAX_HPB_SINGLE_CMD);
>  UFS_ATTRIBUTE(current_power_mode, _POWER_MODE);
>  UFS_ATTRIBUTE(active_icc_level, _ACTIVE_ICC_LVL);
>  UFS_ATTRIBUTE(ooo_data_enabled, _OOO_DATA_EN);
> @@ -864,6 +867,7 @@ UFS_ATTRIBUTE(wb_cur_buf, _CURR_WB_BUFF_SIZE);
> 
>  static struct attribute *ufs_sysfs_attributes[] = {
>  	&dev_attr_boot_lun_enabled.attr,
> +	&dev_attr_max_data_size_hpb_single_cmd.attr,
>  	&dev_attr_current_power_mode.attr,
>  	&dev_attr_active_icc_level.attr,
>  	&dev_attr_ooo_data_enabled.attr,
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index bfb84d2ba990..8c6b38b1b142 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -123,12 +123,13 @@ enum flag_idn {
>  	QUERY_FLAG_IDN_WB_BUFF_FLUSH_EN                 = 0x0F,
>  	QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8     = 0x10,
>  	QUERY_FLAG_IDN_HPB_RESET                        = 0x11,
> +	QUERY_FLAG_IDN_HPB_EN				= 0x12,
>  };
> 
>  /* Attribute idn for Query requests */
>  enum attr_idn {
>  	QUERY_ATTR_IDN_BOOT_LU_EN		= 0x00,
> -	QUERY_ATTR_IDN_RESERVED			= 0x01,
> +	QUERY_ATTR_IDN_MAX_HPB_SINGLE_CMD	= 0x01,
>  	QUERY_ATTR_IDN_POWER_MODE		= 0x02,
>  	QUERY_ATTR_IDN_ACTIVE_ICC_LVL		= 0x03,
>  	QUERY_ATTR_IDN_OOO_DATA_EN		= 0x04,
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index a7cf9278965c..1653c7a7b066 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -2653,7 +2653,12 @@ static int ufshcd_queuecommand(struct Scsi_Host
> *host, struct scsi_cmnd *cmd)
> 
>  	lrbp->req_abort_skip = false;
> 
> -	ufshpb_prep(hba, lrbp);
> +	err = ufshpb_prep(hba, lrbp);
> +	if (err == -EAGAIN) {
> +		lrbp->cmd = NULL;
> +		ufshcd_release(hba);
> +		goto out;
> +	}
> 
>  	ufshcd_comp_scsi_upiu(hba, lrbp);
> 
> @@ -3107,7 +3112,7 @@ int ufshcd_query_attr(struct ufs_hba *hba, enum
> query_opcode opcode,
>   *
>   * Returns 0 for success, non-zero in case of failure
>  */
> -static int ufshcd_query_attr_retry(struct ufs_hba *hba,
> +int ufshcd_query_attr_retry(struct ufs_hba *hba,
>  	enum query_opcode opcode, enum attr_idn idn, u8 index, u8 selector,
>  	u32 *attr_val)
>  {
> @@ -4862,7 +4867,8 @@ static int ufshcd_change_queue_depth(struct
> scsi_device *sdev, int depth)
>  static void ufshcd_hpb_destroy(struct ufs_hba *hba, struct scsi_device 
> *sdev)
>  {
>  	/* skip well-known LU */
> -	if ((sdev->lun >= UFS_UPIU_MAX_UNIT_NUM_ID) || 
> !ufshpb_is_allowed(hba))
> +	if ((sdev->lun >= UFS_UPIU_MAX_UNIT_NUM_ID) ||
> +	    !(hba->dev_info.hpb_enabled) || !ufshpb_is_allowed(hba))
>  		return;
> 
>  	ufshpb_destroy_lu(hba, sdev);
> @@ -7454,8 +7460,18 @@ static int ufs_get_device_desc(struct ufs_hba 
> *hba)
> 
>  	if (dev_info->wspecversion >= UFS_DEV_HPB_SUPPORT_VERSION &&
>  	    (b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT)) {
> -		dev_info->hpb_enabled = true;
> +		bool hpb_en = false;
> +
>  		ufshpb_get_dev_info(hba, desc_buf);
> +
> +		if (!ufshpb_is_legacy(hba))
> +			err = ufshcd_query_flag_retry(hba,
> +						      UPIU_QUERY_OPCODE_READ_FLAG,
> +						      QUERY_FLAG_IDN_HPB_EN, 0,
> +						      &hpb_en);
> +
> +		if (ufshpb_is_legacy(hba) || (!err && hpb_en))
> +			dev_info->hpb_enabled = true;
>  	}
> 
>  	err = ufshcd_read_string_desc(hba, model_index,
> @@ -8028,6 +8044,7 @@ static const struct attribute_group
> *ufshcd_driver_groups[] = {
>  	&ufs_sysfs_lun_attributes_group,
>  #ifdef CONFIG_SCSI_UFS_HPB
>  	&ufs_sysfs_hpb_stat_group,
> +	&ufs_sysfs_hpb_param_group,
>  #endif
>  	NULL,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 008a5f7146c0..8aca8f327981 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -654,6 +654,8 @@ struct ufs_hba_variant_params {
>   * @srgn_size: device reported HPB sub-region size
>   * @slave_conf_cnt: counter to check all lu finished initialization
>   * @hpb_disabled: flag to check if HPB is disabled
> + * @max_hpb_single_cmd: maximum size of single HPB command
> + * @is_legacy: flag to check HPB 1.0
>   */
>  struct ufshpb_dev_info {
>  	int num_lu;
> @@ -661,6 +663,8 @@ struct ufshpb_dev_info {
>  	int srgn_size;
>  	atomic_t slave_conf_cnt;
>  	bool hpb_disabled;
> +	int max_hpb_single_cmd;
> +	bool is_legacy;
>  };
>  #endif
> 
> @@ -1096,6 +1100,9 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
>  			   u8 param_offset,
>  			   u8 *param_read_buf,
>  			   u8 param_size);
> +int ufshcd_query_attr_retry(struct ufs_hba *hba, enum query_opcode 
> opcode,
> +			    enum attr_idn idn, u8 index, u8 selector,
> +			    u32 *attr_val);
>  int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
>  		      enum attr_idn idn, u8 index, u8 selector, u32 *attr_val);
>  int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
> diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
> index f789339f68d9..3ac8b0a9e8d3 100644
> --- a/drivers/scsi/ufs/ufshpb.c
> +++ b/drivers/scsi/ufs/ufshpb.c
> @@ -31,6 +31,11 @@ bool ufshpb_is_allowed(struct ufs_hba *hba)
>  	return !(hba->ufshpb_dev.hpb_disabled);
>  }
> 
> +bool ufshpb_is_legacy(struct ufs_hba *hba)
> +{
> +	return hba->ufshpb_dev.is_legacy;
> +}
> +
>  static struct ufshpb_lu *ufshpb_get_hpb_data(struct scsi_device *sdev)
>  {
>  	return sdev->hostdata;
> @@ -64,9 +69,19 @@ static bool ufshpb_is_write_or_discard_cmd(struct
> scsi_cmnd *cmd)
>  	       op_is_discard(req_op(cmd->request));
>  }
> 
> -static bool ufshpb_is_support_chunk(int transfer_len)
> +static bool ufshpb_is_support_chunk(struct ufshpb_lu *hpb, int 
> transfer_len)
>  {
> -	return transfer_len <= HPB_MULTI_CHUNK_HIGH;
> +	return transfer_len <= hpb->pre_req_max_tr_len;
> +}
> +
> +/*
> + * In this driver, WRITE_BUFFER CMD support 36KB (len=9) ~ 512KB 
> (len=128) as
> + * default. It is possible to change range of transfer_len through 
> sysfs.
> + */
> +static inline bool ufshpb_is_required_wb(struct ufshpb_lu *hpb, int 
> len)
> +{
> +	return (len > hpb->pre_req_min_tr_len &&
> +		len <= hpb->pre_req_max_tr_len);
>  }
> 
>  static bool ufshpb_is_general_lun(int lun)
> @@ -74,8 +89,7 @@ static bool ufshpb_is_general_lun(int lun)
>  	return lun < UFS_UPIU_MAX_UNIT_NUM_ID;
>  }
> 
> -static bool
> -ufshpb_is_pinned_region(struct ufshpb_lu *hpb, int rgn_idx)
> +static bool ufshpb_is_pinned_region(struct ufshpb_lu *hpb, int 
> rgn_idx)
>  {
>  	if (hpb->lu_pinned_end != PINNED_NOT_SET &&
>  	    rgn_idx >= hpb->lu_pinned_start &&
> @@ -264,7 +278,8 @@ ufshpb_get_pos_from_lpn(struct ufshpb_lu *hpb,
> unsigned long lpn, int *rgn_idx,
> 
>  static void
>  ufshpb_set_hpb_read_to_upiu(struct ufshpb_lu *hpb, struct ufshcd_lrb 
> *lrbp,
> -			    u32 lpn, u64 ppn, unsigned int transfer_len)
> +			    u32 lpn, u64 ppn, unsigned int transfer_len,
> +			    int read_id)
>  {
>  	unsigned char *cdb = lrbp->cmd->cmnd;
> 
> @@ -273,15 +288,261 @@ ufshpb_set_hpb_read_to_upiu(struct ufshpb_lu
> *hpb, struct ufshcd_lrb *lrbp,
>  	/* ppn value is stored as big-endian in the host memory */
>  	memcpy(&cdb[6], &ppn, sizeof(u64));
>  	cdb[14] = transfer_len;
> +	cdb[15] = read_id;
> 
>  	lrbp->cmd->cmd_len = UFS_CDB_SIZE;
>  }
> 
> +static inline void ufshpb_set_write_buf_cmd(unsigned char *cdb,
> +					    unsigned long lpn, unsigned int len,
> +					    int read_id)
> +{
> +	cdb[0] = UFSHPB_WRITE_BUFFER;
> +	cdb[1] = UFSHPB_WRITE_BUFFER_PREFETCH_ID;
> +
> +	put_unaligned_be32(lpn, &cdb[2]);
> +	cdb[6] = read_id;
> +	put_unaligned_be16(len * HPB_ENTRY_SIZE, &cdb[7]);
> +
> +	cdb[9] = 0x00;	/* Control = 0x00 */
> +}
> +
> +static struct ufshpb_req *ufshpb_get_pre_req(struct ufshpb_lu *hpb)
> +{
> +	struct ufshpb_req *pre_req;
> +
> +	if (hpb->num_inflight_pre_req >= hpb->throttle_pre_req) {
> +		dev_info(&hpb->sdev_ufs_lu->sdev_dev,
> +			 "pre_req throttle. inflight %d throttle %d",
> +			 hpb->num_inflight_pre_req, hpb->throttle_pre_req);
> +		return NULL;
> +	}
> +
> +	pre_req = list_first_entry_or_null(&hpb->lh_pre_req_free,
> +					   struct ufshpb_req, list_req);
> +	if (!pre_req) {
> +		dev_info(&hpb->sdev_ufs_lu->sdev_dev, "There is no pre_req");
> +		return NULL;
> +	}
> +
> +	list_del_init(&pre_req->list_req);
> +	hpb->num_inflight_pre_req++;
> +
> +	return pre_req;
> +}
> +
> +static inline void ufshpb_put_pre_req(struct ufshpb_lu *hpb,
> +				      struct ufshpb_req *pre_req)
> +{
> +	pre_req->req = NULL;
> +	bio_reset(pre_req->bio);
> +	list_add_tail(&pre_req->list_req, &hpb->lh_pre_req_free);
> +	hpb->num_inflight_pre_req--;
> +}
> +
> +static void ufshpb_pre_req_compl_fn(struct request *req, blk_status_t 
> error)
> +{
> +	struct ufshpb_req *pre_req = (struct ufshpb_req *)req->end_io_data;
> +	struct ufshpb_lu *hpb = pre_req->hpb;
> +	unsigned long flags;
> +
> +	if (error) {
> +		struct scsi_request *rq = scsi_req(req);
> +		struct scsi_sense_hdr sshdr;
> +
> +		dev_err(&hpb->sdev_ufs_lu->sdev_dev, "block status %d", error);
> +		scsi_normalize_sense(rq->sense, SCSI_SENSE_BUFFERSIZE,
> +				     &sshdr);
> +		dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> +			"code %x sense_key %x asc %x ascq %x",
> +			sshdr.response_code,
> +			sshdr.sense_key, sshdr.asc, sshdr.ascq);
> +		dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> +			"byte4 %x byte5 %x byte6 %x additional_len %x",
> +			sshdr.byte4, sshdr.byte5,
> +			sshdr.byte6, sshdr.additional_length);
> +	}
> +
> +	blk_mq_free_request(req);
> +	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> +	ufshpb_put_pre_req(pre_req->hpb, pre_req);
> +	spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +}
> +
> +static int ufshpb_prep_entry(struct ufshpb_req *pre_req, struct page 
> *page)
> +{
> +	struct ufshpb_lu *hpb = pre_req->hpb;
> +	struct ufshpb_region *rgn;
> +	struct ufshpb_subregion *srgn;
> +	u64 *addr;
> +	int offset = 0;
> +	int copied;
> +	unsigned long lpn = pre_req->wb.lpn;
> +	int rgn_idx, srgn_idx, srgn_offset;
> +	unsigned long flags;
> +
> +	addr = page_address(page);
> +	ufshpb_get_pos_from_lpn(hpb, lpn, &rgn_idx, &srgn_idx, &srgn_offset);
> +
> +	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> +
> +next_offset:
> +	rgn = hpb->rgn_tbl + rgn_idx;
> +	srgn = rgn->srgn_tbl + srgn_idx;
> +
> +	if (!ufshpb_is_valid_srgn(rgn, srgn))
> +		goto mctx_error;
> +
> +	if (!srgn->mctx)
> +		goto mctx_error;
> +
> +	copied = ufshpb_fill_ppn_from_page(hpb, srgn->mctx, srgn_offset,
> +					   pre_req->wb.len - offset,
> +					   &addr[offset]);
> +
> +	if (copied < 0)
> +		goto mctx_error;
> +
> +	offset += copied;
> +	srgn_offset += copied;
> +
> +	if (srgn_offset == hpb->entries_per_srgn) {
> +		srgn_offset = 0;
> +
> +		if (++srgn_idx == hpb->srgns_per_rgn) {
> +			srgn_idx = 0;
> +			rgn_idx++;
> +		}
> +	}
> +
> +	if (offset < pre_req->wb.len)
> +		goto next_offset;
> +
> +	spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +	return 0;
> +mctx_error:
> +	spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +	return -ENOMEM;
> +}
> +
> +static int ufshpb_pre_req_add_bio_page(struct ufshpb_lu *hpb,
> +				       struct request_queue *q,
> +				       struct ufshpb_req *pre_req)
> +{
> +	struct page *page = pre_req->wb.m_page;
> +	struct bio *bio = pre_req->bio;
> +	int entries_bytes, ret;
> +
> +	if (!page)
> +		return -ENOMEM;
> +
> +	if (ufshpb_prep_entry(pre_req, page))
> +		return -ENOMEM;
> +
> +	entries_bytes = pre_req->wb.len * sizeof(u64);
> +
> +	ret = bio_add_pc_page(q, bio, page, entries_bytes, 0);
> +	if (ret != entries_bytes) {
> +		dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> +			"bio_add_pc_page fail: %d", ret);
> +		return -ENOMEM;
> +	}
> +	return 0;
> +}
> +
> +static inline int ufshpb_get_read_id(struct ufshpb_lu *hpb)
> +{
> +	if (++hpb->cur_read_id >= MAX_HPB_READ_ID)
> +		hpb->cur_read_id = 1;
> +	return hpb->cur_read_id;
> +}
> +
> +static int ufshpb_execute_pre_req(struct ufshpb_lu *hpb, struct 
> scsi_cmnd *cmd,
> +				  struct ufshpb_req *pre_req, int read_id)
> +{
> +	struct scsi_device *sdev = cmd->device;
> +	struct request_queue *q = sdev->request_queue;
> +	struct request *req;
> +	struct scsi_request *rq;
> +	struct bio *bio = pre_req->bio;
> +
> +	pre_req->hpb = hpb;
> +	pre_req->wb.lpn = sectors_to_logical(cmd->device,
> +					     blk_rq_pos(cmd->request));
> +	pre_req->wb.len = sectors_to_logical(cmd->device,
> +					     blk_rq_sectors(cmd->request));
> +	if (ufshpb_pre_req_add_bio_page(hpb, q, pre_req))
> +		return -ENOMEM;
> +
> +	req = pre_req->req;
> +
> +	/* 1. request setup */
> +	blk_rq_append_bio(req, &bio);
> +	req->rq_disk = NULL;
> +	req->end_io_data = (void *)pre_req;
> +	req->end_io = ufshpb_pre_req_compl_fn;
> +
> +	/* 2. scsi_request setup */
> +	rq = scsi_req(req);
> +	rq->retries = 1;
> +
> +	ufshpb_set_write_buf_cmd(rq->cmd, pre_req->wb.lpn, pre_req->wb.len,
> +				 read_id);
> +	rq->cmd_len = scsi_command_size(rq->cmd);
> +
> +	if (blk_insert_cloned_request(q, req) != BLK_STS_OK)
> +		return -EAGAIN;
> +
> +	hpb->stats.pre_req_cnt++;
> +
> +	return 0;
> +}
> +
> +static int ufshpb_issue_pre_req(struct ufshpb_lu *hpb, struct 
> scsi_cmnd *cmd,
> +				int *read_id)
> +{
> +	struct ufshpb_req *pre_req;
> +	struct request *req = NULL;
> +	unsigned long flags;
> +	int _read_id;
> +	int ret = 0;
> +
> +	req = blk_get_request(cmd->device->request_queue,
> +			      REQ_OP_SCSI_OUT | REQ_SYNC, BLK_MQ_REQ_NOWAIT);
> +	if (IS_ERR(req))
> +		return -EAGAIN;
> +
> +	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> +	pre_req = ufshpb_get_pre_req(hpb);
> +	if (!pre_req) {
> +		ret = -EAGAIN;
> +		goto unlock_out;
> +	}
> +	_read_id = ufshpb_get_read_id(hpb);
> +	spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +
> +	pre_req->req = req;
> +
> +	ret = ufshpb_execute_pre_req(hpb, cmd, pre_req, _read_id);
> +	if (ret)
> +		goto free_pre_req;
> +
> +	*read_id = _read_id;
> +
> +	return ret;
> +free_pre_req:
> +	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> +	ufshpb_put_pre_req(hpb, pre_req);
> +unlock_out:
> +	spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +	blk_put_request(req);
> +	return ret;
> +}
> +
>  /*
>   * This function will set up HPB read command using host-side L2P map 
> data.
> - * In HPB v1.0, maximum size of HPB read command is 4KB.
>   */
> -void ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
> +int ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>  {
>  	struct ufshpb_lu *hpb;
>  	struct ufshpb_region *rgn;
> @@ -291,19 +552,20 @@ void ufshpb_prep(struct ufs_hba *hba, struct
> ufshcd_lrb *lrbp)
>  	u64 ppn;
>  	unsigned long flags;
>  	int transfer_len, rgn_idx, srgn_idx, srgn_offset;
> +	int read_id = 0;
>  	int err = 0;
> 
>  	hpb = ufshpb_get_hpb_data(cmd->device);
>  	if (!hpb)
> -		return;
> +		return -ENODEV;
> 
>  	if (ufshpb_get_state(hpb) == HPB_INIT)
> -		return;
> +		return -ENODEV;
> 
>  	if (ufshpb_get_state(hpb) != HPB_PRESENT) {
>  		dev_notice(&hpb->sdev_ufs_lu->sdev_dev,
>  			   "%s: ufshpb state is not PRESENT", __func__);
> -		return;
> +		return -ENODEV;
>  	}
> 
>  	if (blk_rq_is_scsi(cmd->request) ||
> @@ -314,7 +576,7 @@ void ufshpb_prep(struct ufs_hba *hba, struct
> ufshcd_lrb *lrbp)
>  	transfer_len = sectors_to_logical(cmd->device,
>  					  blk_rq_sectors(cmd->request));
>  	if (unlikely(!transfer_len))
> -		return;
> +		return 0;
> 
>  	lpn = sectors_to_logical(cmd->device, blk_rq_pos(cmd->request));
>  	ufshpb_get_pos_from_lpn(hpb, lpn, &rgn_idx, &srgn_idx, &srgn_offset);
> @@ -327,18 +589,18 @@ void ufshpb_prep(struct ufs_hba *hba, struct
> ufshcd_lrb *lrbp)
>  		ufshpb_set_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset,
>  				 transfer_len);
>  		spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> -		return;
> +		return 0;
>  	}
> 
> -	if (!ufshpb_is_support_chunk(transfer_len))
> -		return;
> +	if (!ufshpb_is_support_chunk(hpb, transfer_len))
> +		return 0;
> 
>  	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
>  	if (ufshpb_test_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset,
>  				   transfer_len)) {
>  		hpb->stats.miss_cnt++;
>  		spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> -		return;
> +		return 0;
>  	}
> 
>  	err = ufshpb_fill_ppn_from_page(hpb, srgn->mctx, srgn_offset, 1, 
> &ppn);
> @@ -351,64 +613,101 @@ void ufshpb_prep(struct ufs_hba *hba, struct
> ufshcd_lrb *lrbp)
>  		 * active state.
>  		 */
>  		dev_err(hba->dev, "get ppn failed. err %d\n", err);
> -		return;
> +		return err;
> +	}
> +	if (!ufshpb_is_legacy(hba) &&
> +	    ufshpb_is_required_wb(hpb, transfer_len)) {
> +		err = ufshpb_issue_pre_req(hpb, cmd, &read_id);
> +		if (err) {
> +			unsigned long timeout;
> +
> +			timeout = cmd->jiffies_at_alloc + msecs_to_jiffies(
> +				  hpb->params.requeue_timeout_ms);
> +
> +			if (time_before(jiffies, timeout))
> +				return -EAGAIN;
> +
> +			hpb->stats.miss_cnt++;
> +			return 0;
> +		}
>  	}
> 
> -	ufshpb_set_hpb_read_to_upiu(hpb, lrbp, lpn, ppn, transfer_len);
> +	ufshpb_set_hpb_read_to_upiu(hpb, lrbp, lpn, ppn, transfer_len, 
> read_id);
> 
>  	hpb->stats.hit_cnt++;
> +	return 0;
>  }
> -static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
> -					     struct ufshpb_subregion *srgn)
> +
> +static struct ufshpb_req *ufshpb_get_req(struct ufshpb_lu *hpb,
> +					 int rgn_idx, enum req_opf dir,
> +					 bool atomic)

You didn't mention this change in cover letter. And I don't see anyone
is passing "atomic" as true, neither in your patches nor Avri's V6 
series
(from ufshpb_issue_umap_single_req()). If no one is using the flag, then
this is dead code. If Avri needs this flag, he can add it in host 
control
mode patches. Do I miss anything?

Thanks,
Can Guo.

>  {
> -	struct ufshpb_req *map_req;
> +	struct ufshpb_req *rq;
>  	struct request *req;
> -	struct bio *bio;
>  	int retries = HPB_MAP_REQ_RETRIES;
> 
> -	map_req = kmem_cache_alloc(hpb->map_req_cache, GFP_KERNEL);
> -	if (!map_req)
> +	rq = kmem_cache_alloc(hpb->map_req_cache, GFP_ATOMIC);
> +	if (!rq)
>  		return NULL;
> 
>  retry:
> -	req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
> -			      REQ_OP_SCSI_IN, BLK_MQ_REQ_NOWAIT);
> +	req = blk_get_request(hpb->sdev_ufs_lu->request_queue, dir,
> +			      BLK_MQ_REQ_NOWAIT);
> 
> -	if ((PTR_ERR(req) == -EWOULDBLOCK) && (--retries > 0)) {
> +	if (!atomic && (PTR_ERR(req) == -EWOULDBLOCK) && (--retries > 0)) {
>  		usleep_range(3000, 3100);
>  		goto retry;
>  	}
> 
>  	if (IS_ERR(req))
> -		goto free_map_req;
> +		goto free_rq;
> +
> +	rq->hpb = hpb;
> +	rq->req = req;
> +	rq->rb.rgn_idx = rgn_idx;
> +
> +	return rq;
> +
> +free_rq:
> +	kmem_cache_free(hpb->map_req_cache, rq);
> +	return NULL;
> +}
> +
> +static void ufshpb_put_req(struct ufshpb_lu *hpb, struct ufshpb_req 
> *rq)
> +{
> +	blk_put_request(rq->req);
> +	kmem_cache_free(hpb->map_req_cache, rq);
> +}
> +
> +static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
> +					     struct ufshpb_subregion *srgn)
> +{
> +	struct ufshpb_req *map_req;
> +	struct bio *bio;
> +
> +	map_req = ufshpb_get_req(hpb, srgn->rgn_idx, REQ_OP_SCSI_IN, false);
> +	if (!map_req)
> +		return NULL;
> 
>  	bio = bio_alloc(GFP_KERNEL, hpb->pages_per_srgn);
>  	if (!bio) {
> -		blk_put_request(req);
> -		goto free_map_req;
> +		ufshpb_put_req(hpb, map_req);
> +		return NULL;
>  	}
> 
> -	map_req->hpb = hpb;
> -	map_req->req = req;
>  	map_req->bio = bio;
> 
> -	map_req->rgn_idx = srgn->rgn_idx;
> -	map_req->srgn_idx = srgn->srgn_idx;
> -	map_req->mctx = srgn->mctx;
> +	map_req->rb.srgn_idx = srgn->srgn_idx;
> +	map_req->rb.mctx = srgn->mctx;
> 
>  	return map_req;
> -
> -free_map_req:
> -	kmem_cache_free(hpb->map_req_cache, map_req);
> -	return NULL;
>  }
> 
>  static void ufshpb_put_map_req(struct ufshpb_lu *hpb,
>  			       struct ufshpb_req *map_req)
>  {
>  	bio_put(map_req->bio);
> -	blk_put_request(map_req->req);
> -	kmem_cache_free(hpb->map_req_cache, map_req);
> +	ufshpb_put_req(hpb, map_req);
>  }
> 
>  static int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
> @@ -491,6 +790,13 @@ static void ufshpb_activate_subregion(struct
> ufshpb_lu *hpb,
>  	srgn->srgn_state = HPB_SRGN_VALID;
>  }
> 
> +static void ufshpb_umap_req_compl_fn(struct request *req, blk_status_t 
> error)
> +{
> +	struct ufshpb_req *umap_req = (struct ufshpb_req *)req->end_io_data;
> +
> +	ufshpb_put_req(umap_req->hpb, umap_req);
> +}
> +
>  static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t 
> error)
>  {
>  	struct ufshpb_req *map_req = (struct ufshpb_req *) req->end_io_data;
> @@ -498,8 +804,8 @@ static void ufshpb_map_req_compl_fn(struct request
> *req, blk_status_t error)
>  	struct ufshpb_subregion *srgn;
>  	unsigned long flags;
> 
> -	srgn = hpb->rgn_tbl[map_req->rgn_idx].srgn_tbl +
> -		map_req->srgn_idx;
> +	srgn = hpb->rgn_tbl[map_req->rb.rgn_idx].srgn_tbl +
> +		map_req->rb.srgn_idx;
> 
>  	ufshpb_clear_dirty_bitmap(hpb, srgn);
>  	spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> @@ -509,6 +815,16 @@ static void ufshpb_map_req_compl_fn(struct
> request *req, blk_status_t error)
>  	ufshpb_put_map_req(map_req->hpb, map_req);
>  }
> 
> +static void ufshpb_set_unmap_cmd(unsigned char *cdb, struct 
> ufshpb_region *rgn)
> +{
> +	cdb[0] = UFSHPB_WRITE_BUFFER;
> +	cdb[1] = rgn ? UFSHPB_WRITE_BUFFER_INACT_SINGLE_ID :
> +			  UFSHPB_WRITE_BUFFER_INACT_ALL_ID;
> +	if (rgn)
> +		put_unaligned_be16(rgn->rgn_idx, &cdb[2]);
> +	cdb[9] = 0x00;
> +}
> +
>  static void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
>  				    int srgn_idx, int srgn_mem_size)
>  {
> @@ -522,6 +838,25 @@ static void ufshpb_set_read_buf_cmd(unsigned char
> *cdb, int rgn_idx,
>  	cdb[9] = 0x00;
>  }
> 
> +static int ufshpb_execute_umap_req(struct ufshpb_lu *hpb,
> +				   struct ufshpb_req *umap_req,
> +				   struct ufshpb_region *rgn)
> +{
> +	struct request *req;
> +	struct scsi_request *rq;
> +
> +	req = umap_req->req;
> +	req->timeout = 0;
> +	req->end_io_data = (void *)umap_req;
> +	rq = scsi_req(req);
> +	ufshpb_set_unmap_cmd(rq->cmd, rgn);
> +	rq->cmd_len = HPB_WRITE_BUFFER_CMD_LENGTH;
> +
> +	blk_execute_rq_nowait(NULL, req, 1, ufshpb_umap_req_compl_fn);
> +
> +	return 0;
> +}
> +
>  static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
>  				  struct ufshpb_req *map_req, bool last)
>  {
> @@ -534,12 +869,12 @@ static int ufshpb_execute_map_req(struct 
> ufshpb_lu *hpb,
> 
>  	q = hpb->sdev_ufs_lu->request_queue;
>  	for (i = 0; i < hpb->pages_per_srgn; i++) {
> -		ret = bio_add_pc_page(q, map_req->bio, map_req->mctx->m_page[i],
> +		ret = bio_add_pc_page(q, map_req->bio, map_req->rb.mctx->m_page[i],
>  				      PAGE_SIZE, 0);
>  		if (ret != PAGE_SIZE) {
>  			dev_err(&hpb->sdev_ufs_lu->sdev_dev,
>  				   "bio_add_pc_page fail %d - %d\n",
> -				   map_req->rgn_idx, map_req->srgn_idx);
> +				   map_req->rb.rgn_idx, map_req->rb.srgn_idx);
>  			return ret;
>  		}
>  	}
> @@ -555,8 +890,8 @@ static int ufshpb_execute_map_req(struct ufshpb_lu 
> *hpb,
>  	if (unlikely(last))
>  		mem_size = hpb->last_srgn_entries * HPB_ENTRY_SIZE;
> 
> -	ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> -				map_req->srgn_idx, mem_size);
> +	ufshpb_set_read_buf_cmd(rq->cmd, map_req->rb.rgn_idx,
> +				map_req->rb.srgn_idx, mem_size);
>  	rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> 
>  	blk_execute_rq_nowait(NULL, req, 1, ufshpb_map_req_compl_fn);
> @@ -688,6 +1023,31 @@ static void ufshpb_purge_active_subregion(struct
> ufshpb_lu *hpb,
>  	}
>  }
> 
> +static int ufshpb_issue_umap_req(struct ufshpb_lu *hpb,
> +				 struct ufshpb_region *rgn, bool atomic)
> +{
> +	struct ufshpb_req *umap_req;
> +	int rgn_idx = rgn ? rgn->rgn_idx : 0;
> +
> +	umap_req = ufshpb_get_req(hpb, rgn_idx, REQ_OP_SCSI_OUT, atomic);
> +	if (!umap_req)
> +		return -ENOMEM;
> +
> +	if (ufshpb_execute_umap_req(hpb, umap_req, rgn))
> +		goto free_umap_req;
> +
> +	return 0;
> +
> +free_umap_req:
> +	ufshpb_put_req(hpb, umap_req);
> +	return -EAGAIN;
> +}
> +
> +static int ufshpb_issue_umap_all_req(struct ufshpb_lu *hpb)
> +{
> +	return ufshpb_issue_umap_req(hpb, NULL, false);
> +}
> +
>  static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
>  				  struct ufshpb_region *rgn)
>  {
> @@ -1210,6 +1570,17 @@ static void ufshpb_lu_parameter_init(struct 
> ufs_hba *hba,
>  	u32 entries_per_rgn;
>  	u64 rgn_mem_size, tmp;
> 
> +	/* for pre_req */
> +	hpb->pre_req_min_tr_len = hpb_dev_info->max_hpb_single_cmd + 1;
> +
> +	if (ufshpb_is_legacy(hba))
> +		hpb->pre_req_max_tr_len = HPB_LEGACY_CHUNK_HIGH;
> +	else
> +		hpb->pre_req_max_tr_len = max(HPB_MULTI_CHUNK_HIGH,
> +					      hpb->pre_req_min_tr_len);
> +
> +	hpb->cur_read_id = 0;
> +
>  	hpb->lu_pinned_start = hpb_lu_info->pinned_start;
>  	hpb->lu_pinned_end = hpb_lu_info->num_pinned ?
>  		(hpb_lu_info->pinned_start + hpb_lu_info->num_pinned - 1)
> @@ -1357,7 +1728,7 @@ ufshpb_sysfs_attr_show_func(rb_active_cnt);
>  ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
>  ufshpb_sysfs_attr_show_func(map_req_cnt);
> 
> -static struct attribute *hpb_dev_attrs[] = {
> +static struct attribute *hpb_dev_stat_attrs[] = {
>  	&dev_attr_hit_cnt.attr,
>  	&dev_attr_miss_cnt.attr,
>  	&dev_attr_rb_noti_cnt.attr,
> @@ -1368,10 +1739,118 @@ static struct attribute *hpb_dev_attrs[] = {
>  };
> 
>  struct attribute_group ufs_sysfs_hpb_stat_group = {
> -	.name = "hpb_sysfs",
> -	.attrs = hpb_dev_attrs,
> +	.name = "hpb_stat_sysfs",
> +	.attrs = hpb_dev_stat_attrs,
>  };
> 
> +/* SYSFS functions */
> +#define ufshpb_sysfs_param_show_func(__name)				\
> +static ssize_t __name##_show(struct device *dev,			\
> +	struct device_attribute *attr, char *buf)			\
> +{									\
> +	struct scsi_device *sdev = to_scsi_device(dev);			\
> +	struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);		\
> +	if (!hpb)							\
> +		return -ENODEV;						\
> +									\
> +	return sysfs_emit(buf, "%d\n", hpb->params.__name);		\
> +}
> +
> +ufshpb_sysfs_param_show_func(requeue_timeout_ms);
> +static ssize_t
> +requeue_timeout_ms_store(struct device *dev, struct device_attribute 
> *attr,
> +			 const char *buf, size_t count)
> +{
> +	struct scsi_device *sdev = to_scsi_device(dev);
> +	struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
> +	int val;
> +
> +	if (!hpb)
> +		return -ENODEV;
> +
> +	if (kstrtouint(buf, 0, &val))
> +		return -EINVAL;
> +
> +	if (val < 0)
> +		return -EINVAL;
> +
> +	hpb->params.requeue_timeout_ms = val;
> +
> +	return count;
> +}
> +static DEVICE_ATTR_RW(requeue_timeout_ms);
> +
> +static struct attribute *hpb_dev_param_attrs[] = {
> +	&dev_attr_requeue_timeout_ms.attr,
> +	NULL,
> +};
> +
> +struct attribute_group ufs_sysfs_hpb_param_group = {
> +	.name = "hpb_param_sysfs",
> +	.attrs = hpb_dev_param_attrs,
> +};
> +
> +static int ufshpb_pre_req_mempool_init(struct ufshpb_lu *hpb)
> +{
> +	struct ufshpb_req *pre_req = NULL, *t;
> +	int qd = hpb->sdev_ufs_lu->queue_depth / 2;
> +	int i;
> +
> +	INIT_LIST_HEAD(&hpb->lh_pre_req_free);
> +
> +	hpb->pre_req = kcalloc(qd, sizeof(struct ufshpb_req), GFP_KERNEL);
> +	hpb->throttle_pre_req = qd;
> +	hpb->num_inflight_pre_req = 0;
> +
> +	if (!hpb->pre_req)
> +		goto release_mem;
> +
> +	for (i = 0; i < qd; i++) {
> +		pre_req = hpb->pre_req + i;
> +		INIT_LIST_HEAD(&pre_req->list_req);
> +		pre_req->req = NULL;
> +
> +		pre_req->bio = bio_alloc(GFP_KERNEL, 1);
> +		if (!pre_req->bio)
> +			goto release_mem;
> +
> +		pre_req->wb.m_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
> +		if (!pre_req->wb.m_page) {
> +			bio_put(pre_req->bio);
> +			goto release_mem;
> +		}
> +
> +		list_add_tail(&pre_req->list_req, &hpb->lh_pre_req_free);
> +	}
> +
> +	return 0;
> +release_mem:
> +	list_for_each_entry_safe(pre_req, t, &hpb->lh_pre_req_free, list_req) 
> {
> +		list_del_init(&pre_req->list_req);
> +		bio_put(pre_req->bio);
> +		__free_page(pre_req->wb.m_page);
> +	}
> +
> +	kfree(hpb->pre_req);
> +	return -ENOMEM;
> +}
> +
> +static void ufshpb_pre_req_mempool_destroy(struct ufshpb_lu *hpb)
> +{
> +	struct ufshpb_req *pre_req = NULL;
> +	int i;
> +
> +	for (i = 0; i < hpb->throttle_pre_req; i++) {
> +		pre_req = hpb->pre_req + i;
> +		bio_put(hpb->pre_req[i].bio);
> +		if (!pre_req->wb.m_page)
> +			__free_page(hpb->pre_req[i].wb.m_page);
> +		list_del_init(&pre_req->list_req);
> +	}
> +
> +	kfree(hpb->pre_req);
> +}
> +
>  static void ufshpb_stat_init(struct ufshpb_lu *hpb)
>  {
>  	hpb->stats.hit_cnt = 0;
> @@ -1382,6 +1861,11 @@ static void ufshpb_stat_init(struct ufshpb_lu 
> *hpb)
>  	hpb->stats.map_req_cnt = 0;
>  }
> 
> +static void ufshpb_param_init(struct ufshpb_lu *hpb)
> +{
> +	hpb->params.requeue_timeout_ms = HPB_REQUEUE_TIME_MS;
> +}
> +
>  static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu 
> *hpb)
>  {
>  	int ret;
> @@ -1414,14 +1898,24 @@ static int ufshpb_lu_hpb_init(struct ufs_hba
> *hba, struct ufshpb_lu *hpb)
>  		goto release_req_cache;
>  	}
> 
> +	ret = ufshpb_pre_req_mempool_init(hpb);
> +	if (ret) {
> +		dev_err(hba->dev, "ufshpb(%d) pre_req_mempool init fail",
> +			hpb->lun);
> +		goto release_m_page_cache;
> +	}
> +
>  	ret = ufshpb_alloc_region_tbl(hba, hpb);
>  	if (ret)
> -		goto release_m_page_cache;
> +		goto release_pre_req_mempool;
> 
>  	ufshpb_stat_init(hpb);
> +	ufshpb_param_init(hpb);
> 
>  	return 0;
> 
> +release_pre_req_mempool:
> +	ufshpb_pre_req_mempool_destroy(hpb);
>  release_m_page_cache:
>  	kmem_cache_destroy(hpb->m_page_cache);
>  release_req_cache:
> @@ -1430,7 +1924,7 @@ static int ufshpb_lu_hpb_init(struct ufs_hba
> *hba, struct ufshpb_lu *hpb)
>  }
> 
>  static struct ufshpb_lu *
> -ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
> +ufshpb_alloc_hpb_lu(struct ufs_hba *hba, struct scsi_device *sdev,
>  		    struct ufshpb_dev_info *hpb_dev_info,
>  		    struct ufshpb_lu_info *hpb_lu_info)
>  {
> @@ -1441,7 +1935,8 @@ ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
>  	if (!hpb)
>  		return NULL;
> 
> -	hpb->lun = lun;
> +	hpb->lun = sdev->lun;
> +	hpb->sdev_ufs_lu = sdev;
> 
>  	ufshpb_lu_parameter_init(hba, hpb, hpb_dev_info, hpb_lu_info);
> 
> @@ -1451,6 +1946,7 @@ ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
>  		goto release_hpb;
>  	}
> 
> +	sdev->hostdata = hpb;
>  	return hpb;
> 
>  release_hpb:
> @@ -1653,6 +2149,7 @@ void ufshpb_destroy_lu(struct ufs_hba *hba,
> struct scsi_device *sdev)
> 
>  	ufshpb_cancel_jobs(hpb);
> 
> +	ufshpb_pre_req_mempool_destroy(hpb);
>  	ufshpb_destroy_region_tbl(hpb);
> 
>  	kmem_cache_destroy(hpb->map_req_cache);
> @@ -1692,6 +2189,7 @@ static void ufshpb_hpb_lu_prepared(struct ufs_hba 
> *hba)
>  			ufshpb_set_state(hpb, HPB_PRESENT);
>  			if ((hpb->lu_pinned_end - hpb->lu_pinned_start) > 0)
>  				queue_work(ufshpb_wq, &hpb->map_work);
> +			ufshpb_issue_umap_all_req(hpb);
>  		} else {
>  			dev_err(hba->dev, "destroy HPB lu %d\n", hpb->lun);
>  			ufshpb_destroy_lu(hba, sdev);
> @@ -1716,7 +2214,7 @@ void ufshpb_init_hpb_lu(struct ufs_hba *hba,
> struct scsi_device *sdev)
>  	if (ret)
>  		goto out;
> 
> -	hpb = ufshpb_alloc_hpb_lu(hba, lun, &hba->ufshpb_dev,
> +	hpb = ufshpb_alloc_hpb_lu(hba, sdev, &hba->ufshpb_dev,
>  				  &hpb_lu_info);
>  	if (!hpb)
>  		goto out;
> @@ -1724,9 +2222,6 @@ void ufshpb_init_hpb_lu(struct ufs_hba *hba,
> struct scsi_device *sdev)
>  	tot_active_srgn_pages += hpb_lu_info.max_active_rgns *
>  			hpb->srgns_per_rgn * hpb->pages_per_srgn;
> 
> -	hpb->sdev_ufs_lu = sdev;
> -	sdev->hostdata = hpb;
> -
>  out:
>  	/* All LUs are initialized */
>  	if (atomic_dec_and_test(&hba->ufshpb_dev.slave_conf_cnt))
> @@ -1813,8 +2308,9 @@ void ufshpb_get_geo_info(struct ufs_hba *hba, u8 
> *geo_buf)
>  void ufshpb_get_dev_info(struct ufs_hba *hba, u8 *desc_buf)
>  {
>  	struct ufshpb_dev_info *hpb_dev_info = &hba->ufshpb_dev;
> -	int version;
> +	int version, ret;
>  	u8 hpb_mode;
> +	u32 max_hpb_single_cmd = HPB_MULTI_CHUNK_LOW;
> 
>  	hpb_mode = desc_buf[DEVICE_DESC_PARAM_HPB_CONTROL];
>  	if (hpb_mode == HPB_HOST_CONTROL) {
> @@ -1825,13 +2321,27 @@ void ufshpb_get_dev_info(struct ufs_hba *hba,
> u8 *desc_buf)
>  	}
> 
>  	version = get_unaligned_be16(desc_buf + DEVICE_DESC_PARAM_HPB_VER);
> -	if (version != HPB_SUPPORT_VERSION) {
> +	if ((version != HPB_SUPPORT_VERSION) &&
> +	    (version != HPB_SUPPORT_LEGACY_VERSION)) {
>  		dev_err(hba->dev, "%s: HPB %x version is not supported.\n",
>  			__func__, version);
>  		hpb_dev_info->hpb_disabled = true;
>  		return;
>  	}
> 
> +	if (version == HPB_SUPPORT_LEGACY_VERSION)
> +		hpb_dev_info->is_legacy = true;
> +
> +	pm_runtime_get_sync(hba->dev);
> +	ret = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> +		QUERY_ATTR_IDN_MAX_HPB_SINGLE_CMD, 0, 0, &max_hpb_single_cmd);
> +	pm_runtime_put_sync(hba->dev);
> +
> +	if (ret)
> +		dev_err(hba->dev, "%s: idn: read max size of single hpb cmd query
> request failed",
> +			__func__);
> +	hpb_dev_info->max_hpb_single_cmd = max_hpb_single_cmd;
> +
>  	/*
>  	 * Get the number of user logical unit to check whether all
>  	 * scsi_device finish initialization
> diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
> index 6e6a0252dc15..b1128b0ce486 100644
> --- a/drivers/scsi/ufs/ufshpb.h
> +++ b/drivers/scsi/ufs/ufshpb.h
> @@ -30,19 +30,29 @@
>  #define PINNED_NOT_SET				U32_MAX
> 
>  /* hpb support chunk size */
> -#define HPB_MULTI_CHUNK_HIGH			1
> +#define HPB_LEGACY_CHUNK_HIGH			1
> +#define HPB_MULTI_CHUNK_LOW			7
> +#define HPB_MULTI_CHUNK_HIGH			128
> 
>  /* hpb vender defined opcode */
>  #define UFSHPB_READ				0xF8
>  #define UFSHPB_READ_BUFFER			0xF9
>  #define UFSHPB_READ_BUFFER_ID			0x01
> +#define UFSHPB_WRITE_BUFFER			0xFA
> +#define UFSHPB_WRITE_BUFFER_INACT_SINGLE_ID	0x01
> +#define UFSHPB_WRITE_BUFFER_PREFETCH_ID		0x02
> +#define UFSHPB_WRITE_BUFFER_INACT_ALL_ID	0x03
> +#define HPB_WRITE_BUFFER_CMD_LENGTH		10
> +#define MAX_HPB_READ_ID				0x7F
>  #define HPB_READ_BUFFER_CMD_LENGTH		10
>  #define LU_ENABLED_HPB_FUNC			0x02
> 
>  #define HPB_RESET_REQ_RETRIES			10
>  #define HPB_MAP_REQ_RETRIES			5
> +#define HPB_REQUEUE_TIME_MS			0
> 
> -#define HPB_SUPPORT_VERSION			0x100
> +#define HPB_SUPPORT_VERSION			0x200
> +#define HPB_SUPPORT_LEGACY_VERSION		0x100
> 
>  enum UFSHPB_MODE {
>  	HPB_HOST_CONTROL,
> @@ -119,23 +129,38 @@ struct ufshpb_region {
>  	     (i)++)
> 
>  /**
> - * struct ufshpb_req - UFSHPB READ BUFFER (for caching map) request 
> structure
> - * @req: block layer request for READ BUFFER
> - * @bio: bio for holding map page
> - * @hpb: ufshpb_lu structure that related to the L2P map
> + * struct ufshpb_req - HPB related request structure (write/read 
> buffer)
> + * @req: block layer request structure
> + * @bio: bio for this request
> + * @hpb: ufshpb_lu structure that related to
> + * @list_req: ufshpb_req mempool list
> + * @sense: store its sense data
>   * @mctx: L2P map information
>   * @rgn_idx: target region index
>   * @srgn_idx: target sub-region index
>   * @lun: target logical unit number
> + * @m_page: L2P map information data for pre-request
> + * @len: length of host-side cached L2P map in m_page
> + * @lpn: start LPN of L2P map in m_page
>   */
>  struct ufshpb_req {
>  	struct request *req;
>  	struct bio *bio;
>  	struct ufshpb_lu *hpb;
> -	struct ufshpb_map_ctx *mctx;
> -
> -	unsigned int rgn_idx;
> -	unsigned int srgn_idx;
> +	struct list_head list_req;
> +	union {
> +		struct {
> +			struct ufshpb_map_ctx *mctx;
> +			unsigned int rgn_idx;
> +			unsigned int srgn_idx;
> +			unsigned int lun;
> +		} rb;
> +		struct {
> +			struct page *m_page;
> +			unsigned int len;
> +			unsigned long lpn;
> +		} wb;
> +	};
>  };
> 
>  struct victim_select_info {
> @@ -144,6 +169,10 @@ struct victim_select_info {
>  	atomic_t active_cnt;
>  };
> 
> +struct ufshpb_params {
> +	unsigned int requeue_timeout_ms;
> +};
> +
>  struct ufshpb_stats {
>  	u64 hit_cnt;
>  	u64 miss_cnt;
> @@ -151,6 +180,7 @@ struct ufshpb_stats {
>  	u64 rb_active_cnt;
>  	u64 rb_inactive_cnt;
>  	u64 map_req_cnt;
> +	u64 pre_req_cnt;
>  };
> 
>  struct ufshpb_lu {
> @@ -166,6 +196,15 @@ struct ufshpb_lu {
>  	struct list_head lh_act_srgn; /* hold rsp_list_lock */
>  	struct list_head lh_inact_rgn; /* hold rsp_list_lock */
> 
> +	/* pre request information */
> +	struct ufshpb_req *pre_req;
> +	int num_inflight_pre_req;
> +	int throttle_pre_req;
> +	struct list_head lh_pre_req_free;
> +	int cur_read_id;
> +	int pre_req_min_tr_len;
> +	int pre_req_max_tr_len;
> +
>  	/* cached L2P map management worker */
>  	struct work_struct map_work;
> 
> @@ -190,6 +229,7 @@ struct ufshpb_lu {
>  	u32 pages_per_srgn;
> 
>  	struct ufshpb_stats stats;
> +	struct ufshpb_params params;
> 
>  	struct kmem_cache *map_req_cache;
>  	struct kmem_cache *m_page_cache;
> @@ -201,7 +241,7 @@ struct ufs_hba;
>  struct ufshcd_lrb;
> 
>  #ifndef CONFIG_SCSI_UFS_HPB
> -static void ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) 
> {}
> +static int ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
> { return 0; }
>  static void ufshpb_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb 
> *lrbp) {}
>  static void ufshpb_resume(struct ufs_hba *hba) {}
>  static void ufshpb_suspend(struct ufs_hba *hba) {}
> @@ -214,8 +254,9 @@ static void ufshpb_remove(struct ufs_hba *hba) {}
>  static bool ufshpb_is_allowed(struct ufs_hba *hba) { return false; }
>  static void ufshpb_get_geo_info(struct ufs_hba *hba, u8 *geo_buf) {}
>  static void ufshpb_get_dev_info(struct ufs_hba *hba, u8 *desc_buf) {}
> +static bool ufshpb_is_legacy(struct ufs_hba *hba) { return false; }
>  #else
> -void ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
> +int ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
>  void ufshpb_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
>  void ufshpb_resume(struct ufs_hba *hba);
>  void ufshpb_suspend(struct ufs_hba *hba);
> @@ -228,7 +269,9 @@ void ufshpb_remove(struct ufs_hba *hba);
>  bool ufshpb_is_allowed(struct ufs_hba *hba);
>  void ufshpb_get_geo_info(struct ufs_hba *hba, u8 *geo_buf);
>  void ufshpb_get_dev_info(struct ufs_hba *hba, u8 *desc_buf);
> +bool ufshpb_is_legacy(struct ufs_hba *hba);
>  extern struct attribute_group ufs_sysfs_hpb_stat_group;
> +extern struct attribute_group ufs_sysfs_hpb_param_group;
>  #endif
> 
>  #endif /* End of Header */