diff mbox series

[RFC,v2,4/5] scsi: ufs: L2P map management for HPB read

Message ID 231786897.01592214002170.JavaMail.epsvc@epcpadp1 (mailing list archive)
State Superseded
Headers show
Series scsi: ufs: Add Host Performance Booster Support | expand

Commit Message

Daejun Park June 15, 2020, 9:30 a.m. UTC
This is a patch for managing L2P map in HPB module.

The HPB divides logical addresses into several regions. A region consists
of several sub-regions. The sub-region is a basic unit where L2P mapping is
managed. The driver loads L2P mapping data of each sub-region. The loaded
sub-region is called active-state. The HPB driver unloads L2P mapping data
as region unit. The unloaded region is called inactive-state.

Sub-region/region candidates to be loaded and unloaded are delivered from
the UFS device. The UFS device delivers the recommended active sub-region
and inactivate region to the driver using sensedata.
The HPB module performs L2P mapping management on the host through the
delivered information.

A pinned region is a pre-set regions on the UFS device that is always
activate-state.

The data structure for map data request and L2P map uses mempool API,
minimizing allocation overhead while avoiding static allocation.

The map_work manages active/inactive by 2 "to-do" lists.
Each hpb lun maintains 2 "to-do" lists:
  hpb->lh_inact_rgn - regions to be inactivated, and
  hpb->lh_act_srgn - subregions to be activated
Those lists are maintained on IO completion.

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/ufshpb.c | 971 +++++++++++++++++++++++++++++++++++++-
 drivers/scsi/ufs/ufshpb.h |  72 +++
 2 files changed, 1040 insertions(+), 3 deletions(-)

Comments

Bean Huo June 15, 2020, 1:35 p.m. UTC | #1
Hi Daejun


On Mon, 2020-06-15 at 18:30 +0900, Daejun Park wrote:
> +static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
> +                                 struct ufshpb_req *map_req)
> +{
> +       struct request_queue *q;
> +       struct request *req;
> +       struct scsi_request *rq;
> +       int ret = 0;
> +
> +       q = hpb->sdev_ufs_lu->request_queue;
> +       ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
> +                                         map_req->mctx);
> +       if (ret) {
> +               dev_notice(&hpb->hpb_lu_dev,
> +                          "map_req_add_bio_page fail %d - %d\n",
> +                          map_req->rgn_idx, map_req->srgn_idx);
> +               return ret;
> +       }
> +
> +       req = map_req->req;
> +
> +       blk_rq_append_bio(req, &map_req->bio);
> +
> +       req->timeout = 0;
> +       req->end_io_data = (void *)map_req;
> +
> +       rq = scsi_req(req);
> +       ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> +                               map_req->srgn_idx, hpb-
> >srgn_mem_size);
> +       rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> +
> +       blk_execute_rq_nowait(q, NULL, req, 1,
> ufshpb_map_req_compl_fn);


HPB map_req is now being en-queued in sdev->request_queue.
This is ok for the HPB v1.0. Have you ever been thinking about
changing this way to directly issue HPB requests to UFS?

Actually, there are two reasons for this way:

1. Latency of loading mapping entries is lower comparing to your curret
approach.
2. Also, it is preparing for the HPB v2.0.  After all HPB 1.0 only
supports 4KB read, this is useless, I am looking for the HPB v2.0.


Thanks,
Bean
Daejun Park June 16, 2020, 1:17 a.m. UTC | #2
Hi Bean
> 
> 
> On Mon, 2020-06-15 at 18:30 +0900, Daejun Park wrote:
> > +static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
> > +                                 struct ufshpb_req *map_req)
> > +{
> > +       struct request_queue *q;
> > +       struct request *req;
> > +       struct scsi_request *rq;
> > +       int ret = 0;
> > +
> > +       q = hpb->sdev_ufs_lu->request_queue;
> > +       ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
> > +                                         map_req->mctx);
> > +       if (ret) {
> > +               dev_notice(&hpb->hpb_lu_dev,
> > +                          "map_req_add_bio_page fail %d - %d\n",
> > +                          map_req->rgn_idx, map_req->srgn_idx);
> > +               return ret;
> > +       }
> > +
> > +       req = map_req->req;
> > +
> > +       blk_rq_append_bio(req, &map_req->bio);
> > +
> > +       req->timeout = 0;
> > +       req->end_io_data = (void *)map_req;
> > +
> > +       rq = scsi_req(req);
> > +       ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> > +                               map_req->srgn_idx, hpb-
> > >srgn_mem_size);
> > +       rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> > +
> > +       blk_execute_rq_nowait(q, NULL, req, 1,
> > ufshpb_map_req_compl_fn);
> 
> 
> HPB map_req is now being en-queued in sdev->request_queue.
> This is ok for the HPB v1.0. Have you ever been thinking about
> changing this way to directly issue HPB requests to UFS?
I think it is enough to support HPB.

> Actually, there are two reasons for this way:
> 
> 1. Latency of loading mapping entries is lower comparing to your curret
> approach.
Our map request style utilizes block layer API. It makes the codes keep
simple and reliable. Also, I think the latency of loading mapping entries 
is not critical for HPB. Futhermore, I think the other requests from
user is important than loading mapping entries. If the map_work issues map
request directly, the user requests can be disturbed by map requests.

> 2. Also, it is preparing for the HPB v2.0.  After all HPB 1.0 only
> supports 4KB read, this is useless, I am looking for the HPB v2.0.
I don't understand this comment. In HPB v2.0, this code can be used without
changing.

Thanks,
Daejun
Avri Altman June 17, 2020, 11:44 a.m. UTC | #3
> +
> +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
> +{
> +       struct ufshpb_map_ctx *mctx;
> +       int i, j;
> +
> +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> +       if (!mctx)
> +               return NULL;
So you use ufshpb_host_map_kbytes as the min_nr in your mempool_create,
But you know that you need max_lru_active_cnt x srgns_per_rgn such mapping context elements.
So you are
a) failing to provide the slab allocator an information that you already have, and
b) selecting from a finite pool will assure that you'll never exceed max-active-regions,
   even if some corner case fails your logic.
Daejun Park June 18, 2020, 1:03 a.m. UTC | #4
> +
> > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
> > +{
> > +       struct ufshpb_map_ctx *mctx;
> > +       int i, j;
> > +
> > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > +       if (!mctx)
> > +               return NULL;
> So you use ufshpb_host_map_kbytes as the min_nr in your mempool_create,
> But you know that you need max_lru_active_cnt x srgns_per_rgn such mapping context elements.
> So you are
> a) failing to provide the slab allocator an information that you already have, and
> b) selecting from a finite pool will assure that you'll never exceed max-active-regions,
>    even if some corner case fails your logic.
It was intend to provide user-configurable pre-allocated memory to reduce
latency due to memory allocation. The value of ufshpb_host_map_kbytes can
be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.

Thanks,
Daejun
Avri Altman June 18, 2020, 6:12 a.m. UTC | #5
> > +
> > > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu
> *hpb)
> > > +{
> > > +       struct ufshpb_map_ctx *mctx;
> > > +       int i, j;
> > > +
> > > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > > +       if (!mctx)
> > > +               return NULL;
> > So you use ufshpb_host_map_kbytes as the min_nr in your
> mempool_create,
> > But you know that you need max_lru_active_cnt x srgns_per_rgn such
> mapping context elements.
> > So you are
> > a) failing to provide the slab allocator an information that you already have,
> and
> > b) selecting from a finite pool will assure that you'll never exceed max-
> active-regions,
> >    even if some corner case fails your logic.
> It was intend to provide user-configurable pre-allocated memory to reduce
> latency due to memory allocation. The value of ufshpb_host_map_kbytes can
> be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.
Ok, I see your point.
It is as if you expect that a "user" will query the unit descriptors first,
Make some calculations, and then will run modprobe with the proper value.
Are you assuming that an "intelligent" user does all that?

The reasonable scenario IMO, is that OEMs will initiate a service in their
ramdisk/init.rc with some default value.

Don't you see the damage potential in using a wrong value here?
Avri Altman June 18, 2020, 10:22 a.m. UTC | #6
> +static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
> +{
> +       struct ufshpb_region *rgn;
> +       struct ufshpb_subregion *srgn;
> +       struct ufshpb_map_ctx *mctx;
mctx  doesn't really do anything here

> +       unsigned long flags;
> +       int ret = 0;
> +
> +       spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +       while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
> +                                               struct ufshpb_subregion,
> +                                               list_act_srgn))) {
> +               list_del_init(&srgn->list_act_srgn);
> +               spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> +
> +               rgn = hpb->rgn_tbl + srgn->rgn_idx;
> +               mctx = NULL;
> +               ret = ufshpb_add_region(hpb, rgn);
> +               if (ret)
> +                       break;
> +
> +               ret = ufshpb_issue_map_req(hpb, rgn, srgn);
> +               if (ret) {
> +                       dev_notice(&hpb->hpb_lu_dev,
> +                           "issue map_req failed. ret %d, region %d - %d\n",
> +                           ret, rgn->rgn_idx, srgn->srgn_idx);
> +                       break;
> +               }
> +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +       }
> +
> +       if (ret) {
> +               dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
> +                          rgn->rgn_idx, srgn->srgn_idx);
> +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +               ufshpb_add_active_list(hpb, rgn, srgn);
> +       }
> +       spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> +}
Daejun Park June 19, 2020, 12:12 a.m. UTC | #7
> +static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
> > +{
> > +       struct ufshpb_region *rgn;
> > +       struct ufshpb_subregion *srgn;
> > +       struct ufshpb_map_ctx *mctx;
> mctx  doesn't really do anything here

OK, I will delete it.

> > +       unsigned long flags;
> > +       int ret = 0;
> > +
> > +       spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +       while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
> > +                                               struct ufshpb_subregion,
> > +                                               list_act_srgn))) {
> > +               list_del_init(&srgn->list_act_srgn);
> > +               spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> > +
> > +               rgn = hpb->rgn_tbl + srgn->rgn_idx;
> > +               mctx = NULL;
> > +               ret = ufshpb_add_region(hpb, rgn);
> > +               if (ret)
> > +                       break;
> > +
> > +               ret = ufshpb_issue_map_req(hpb, rgn, srgn);
> > +               if (ret) {
> > +                       dev_notice(&hpb->hpb_lu_dev,
> > +                           "issue map_req failed. ret %d, region %d - %d\n",
> > +                           ret, rgn->rgn_idx, srgn->srgn_idx);
> > +                       break;
> > +               }
> > +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +       }
> > +
> > +       if (ret) {
> > +               dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
> > +                          rgn->rgn_idx, srgn->srgn_idx);
> > +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +               ufshpb_add_active_list(hpb, rgn, srgn);
> > +       }
> > +       spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> > +}
> 
>
Daejun Park June 19, 2020, 12:16 a.m. UTC | #8
> > > +
> > > > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu
> > *hpb)
> > > > +{
> > > > +       struct ufshpb_map_ctx *mctx;
> > > > +       int i, j;
> > > > +
> > > > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > > > +       if (!mctx)
> > > > +               return NULL;
> > > So you use ufshpb_host_map_kbytes as the min_nr in your
> > mempool_create,
> > > But you know that you need max_lru_active_cnt x srgns_per_rgn such
> > mapping context elements.
> > > So you are
> > > a) failing to provide the slab allocator an information that you already have,
> > and
> > > b) selecting from a finite pool will assure that you'll never exceed max-
> > active-regions,
> > >    even if some corner case fails your logic.
> > It was intend to provide user-configurable pre-allocated memory to reduce
> > latency due to memory allocation. The value of ufshpb_host_map_kbytes can
> > be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.
> Ok, I see your point.
> It is as if you expect that a "user" will query the unit descriptors first,
> Make some calculations, and then will run modprobe with the proper value.
> Are you assuming that an "intelligent" user does all that?
> 
> The reasonable scenario IMO, is that OEMs will initiate a service in their
> ramdisk/init.rc with some default value.
> 
> Don't you see the damage potential in using a wrong value here?
> 
I understand your scenario. I will remove module parameter and set min_nr
value of memory pool as "max_lru_active_cnt x srgns_per_rgn" size.

Thanks,
Daejun
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 07490679d2f1..6229c6fcb5e1 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -25,6 +25,63 @@  static inline int ufshpb_is_valid_srgn(struct ufshpb_region *rgn,
 		srgn->srgn_state == HPB_SRGN_VALID;
 }
 
+static inline bool ufshpb_is_general_lun(int lun)
+{
+	return lun < UFS_UPIU_MAX_UNIT_NUM_ID;
+}
+
+static inline 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 &&
+	    rgn_idx <= hpb->lu_pinned_end)
+		return true;
+
+	return false;
+}
+
+static bool ufshpb_is_empty_rsp_lists(struct ufshpb_lu *hpb)
+{
+	bool ret = true;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	if (!list_empty(&hpb->lh_inact_rgn) || !list_empty(&hpb->lh_act_srgn))
+		ret = false;
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+	return ret;
+}
+
+static inline int ufshpb_may_field_valid(struct ufs_hba *hba,
+					 struct ufshcd_lrb *lrbp,
+					 struct ufshpb_rsp_field *rsp_field)
+{
+	if (be16_to_cpu(rsp_field->sense_data_len) != DEV_SENSE_SEG_LEN ||
+	    rsp_field->desc_type != DEV_DES_TYPE ||
+	    rsp_field->additional_len != DEV_ADDITIONAL_LEN ||
+	    rsp_field->hpb_type == HPB_RSP_NONE ||
+	    rsp_field->active_rgn_cnt > MAX_ACTIVE_NUM ||
+	    rsp_field->inactive_rgn_cnt > MAX_INACTIVE_NUM ||
+	    (!rsp_field->active_rgn_cnt && !rsp_field->inactive_rgn_cnt))
+		return -EINVAL;
+
+	if (!ufshpb_is_general_lun(lrbp->lun)) {
+		dev_warn(hba->dev, "ufshpb: lun(%d) not supported\n",
+			 lrbp->lun);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+
+static inline struct ufshpb_lu *ufshpb_get_hpb_data(struct scsi_cmnd *cmd)
+{
+	return cmd->device->hostdata;
+}
+
 static inline int ufshpb_get_state(struct ufshpb_lu *hpb)
 {
 	return atomic_read(&hpb->hpb_state);
@@ -59,6 +116,767 @@  static inline void ufshpb_lu_put(struct ufshpb_lu *hpb)
 	put_device(&hpb->hpb_lu_dev);
 }
 
+static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
+					     struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_req *map_req;
+	struct request *req;
+	struct bio *bio;
+
+	map_req = kmem_cache_alloc(hpb->map_req_cache, GFP_KERNEL);
+	if (!map_req)
+		return NULL;
+
+	req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
+			      REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
+	if (IS_ERR(req))
+		goto free_map_req;
+
+	bio = bio_alloc(GFP_KERNEL, hpb->pages_per_srgn);
+	if (!bio) {
+		blk_put_request(req);
+		goto free_map_req;
+	}
+
+	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->lun = hpb->lun;
+
+	return map_req;
+
+free_map_req:
+	kmem_cache_free(hpb->map_req_cache, map_req);
+	return NULL;
+}
+
+static inline 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);
+}
+
+
+static inline int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
+				     struct ufshpb_subregion *srgn)
+{
+	WARN_ON(!srgn->mctx);
+	bitmap_zero(srgn->mctx->ppn_dirty, hpb->entries_per_srgn);
+	return 0;
+}
+
+static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int rgn_idx,
+				      int srgn_idx)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+
+	rgn = hpb->rgn_tbl + rgn_idx;
+	srgn = rgn->srgn_tbl + srgn_idx;
+
+	list_del_init(&rgn->list_inact_rgn);
+
+	if (list_empty(&srgn->list_act_srgn))
+		list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+}
+
+static void ufshpb_update_inactive_info(struct ufshpb_lu *hpb, int rgn_idx)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	rgn = hpb->rgn_tbl + rgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		list_del_init(&srgn->list_act_srgn);
+	}
+
+	if (list_empty(&rgn->list_inact_rgn))
+		list_add_tail(&rgn->list_inact_rgn, &hpb->lh_inact_rgn);
+}
+
+static void ufshpb_activate_subregion(struct ufshpb_lu *hpb,
+					  struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_region *rgn;
+
+	/*
+	 * If there is no mctx in subregion
+	 * after I/O progress for HPB_READ_BUFFER, the region to which the
+	 * subregion belongs was evicted.
+	 * Mask sure the the region must not evict in I/O progress
+	 */
+	WARN_ON(!srgn->mctx);
+
+	rgn = hpb->rgn_tbl + srgn->rgn_idx;
+
+	if (unlikely(rgn->rgn_state == HPB_RGN_INACTIVE)) {
+		dev_err(&hpb->hpb_lu_dev,
+			"region %d subregion %d evicted\n",
+			srgn->rgn_idx, srgn->srgn_idx);
+		return;
+	}
+	srgn->srgn_state = HPB_SRGN_VALID;
+}
+
+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;
+	struct ufshpb_lu *hpb = map_req->hpb;
+	struct ufshpb_subregion *srgn;
+	unsigned long flags;
+
+	srgn = hpb->rgn_tbl[map_req->rgn_idx].srgn_tbl +
+		map_req->srgn_idx;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	ufshpb_activate_subregion(hpb, srgn);
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+
+	ufshpb_put_map_req(map_req->hpb, map_req);
+	ufshpb_lu_put(hpb);
+}
+
+static inline void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
+					   int srgn_idx, int srgn_mem_size)
+{
+	cdb[0] = UFSHPB_READ_BUFFER;
+	cdb[1] = UFSHPB_READ_BUFFER_ID;
+
+	put_unaligned_be16(rgn_idx, &cdb[2]);
+	put_unaligned_be16(srgn_idx, &cdb[4]);
+	put_unaligned_be24(srgn_mem_size, &cdb[6]);
+
+	cdb[9] = 0x00;
+}
+
+static int ufshpb_map_req_add_bio_page(struct ufshpb_lu *hpb,
+				       struct request_queue *q, struct bio *bio,
+				       struct ufshpb_map_ctx *mctx)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++) {
+		ret = bio_add_pc_page(q, bio, mctx->m_page[i], PAGE_SIZE, 0);
+		if (ret != PAGE_SIZE) {
+			dev_notice(&hpb->hpb_lu_dev,
+				   "bio_add_pc_page fail %d\n", ret);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
+				  struct ufshpb_req *map_req)
+{
+	struct request_queue *q;
+	struct request *req;
+	struct scsi_request *rq;
+	int ret = 0;
+
+	q = hpb->sdev_ufs_lu->request_queue;
+	ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
+					  map_req->mctx);
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "map_req_add_bio_page fail %d - %d\n",
+			   map_req->rgn_idx, map_req->srgn_idx);
+		return ret;
+	}
+
+	req = map_req->req;
+
+	blk_rq_append_bio(req, &map_req->bio);
+
+	req->timeout = 0;
+	req->end_io_data = (void *)map_req;
+
+	rq = scsi_req(req);
+	ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
+				map_req->srgn_idx, hpb->srgn_mem_size);
+	rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
+
+	blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_map_req_compl_fn);
+
+	atomic_inc(&hpb->stats.map_req_cnt);
+	return 0;
+}
+
+static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_map_ctx *mctx;
+	int i, j;
+
+	mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
+	if (!mctx)
+		return NULL;
+
+	mctx->m_page = kmem_cache_alloc(hpb->m_page_cache, GFP_KERNEL);
+	if (!mctx->m_page)
+		goto release_mctx;
+
+	mctx->ppn_dirty = bitmap_zalloc(hpb->entries_per_srgn, GFP_KERNEL);
+	if (!mctx->ppn_dirty)
+		goto release_m_page;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++) {
+		mctx->m_page[i] = mempool_alloc(ufshpb_drv.ufshpb_page_pool,
+						GFP_KERNEL);
+		if (!mctx->m_page[i]) {
+			for (j = 0; j < i; j++)
+				mempool_free(mctx->m_page[j],
+					     ufshpb_drv.ufshpb_page_pool);
+			goto release_ppn_dirty;
+		}
+		clear_page(page_address(mctx->m_page[i]));
+	}
+
+	return mctx;
+release_ppn_dirty:
+	bitmap_free(mctx->ppn_dirty);
+release_m_page:
+	kmem_cache_free(hpb->m_page_cache, mctx->m_page);
+release_mctx:
+	mempool_free(mctx, ufshpb_drv.ufshpb_mctx_pool);
+	return NULL;
+}
+
+static inline void ufshpb_put_map_ctx(struct ufshpb_lu *hpb,
+				      struct ufshpb_map_ctx *mctx)
+{
+	int i;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++)
+		mempool_free(mctx->m_page[i],
+			     ufshpb_drv.ufshpb_page_pool);
+
+	bitmap_free(mctx->ppn_dirty);
+	kmem_cache_free(hpb->m_page_cache, mctx->m_page);
+	mempool_free(mctx, ufshpb_drv.ufshpb_mctx_pool);
+}
+
+static int ufshpb_check_issue_state_srgns(struct ufshpb_lu *hpb,
+					  struct ufshpb_region *rgn)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn  = rgn->srgn_tbl + srgn_idx;
+
+		if (srgn->srgn_state == HPB_SRGN_ISSUED)
+			return -EPERM;
+	}
+	return 0;
+}
+
+static inline void ufshpb_add_lru_info(struct victim_select_info *lru_info,
+				       struct ufshpb_region *rgn)
+{
+	rgn->rgn_state = HPB_RGN_ACTIVE;
+	list_add_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
+	atomic_inc(&lru_info->active_cnt);
+}
+
+static inline void ufshpb_hit_lru_info(struct victim_select_info *lru_info,
+				       struct ufshpb_region *rgn)
+{
+	list_move_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
+}
+
+static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
+{
+	struct victim_select_info *lru_info = &hpb->lru_info;
+	struct ufshpb_region *rgn, *victim_rgn = NULL;
+
+	list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) {
+		WARN_ON(!rgn);
+		if (ufshpb_check_issue_state_srgns(hpb, rgn))
+			continue;
+
+		victim_rgn = rgn;
+		break;
+	}
+
+	return victim_rgn;
+}
+
+static inline void ufshpb_cleanup_lru_info(struct victim_select_info *lru_info,
+					   struct ufshpb_region *rgn)
+{
+	list_del_init(&rgn->list_lru_rgn);
+	rgn->rgn_state = HPB_RGN_INACTIVE;
+	atomic_dec(&lru_info->active_cnt);
+}
+
+static inline void ufshpb_purge_active_subregion(struct ufshpb_lu *hpb,
+						 struct ufshpb_subregion *srgn)
+{
+	if (srgn->srgn_state != HPB_SRGN_UNUSED) {
+		ufshpb_put_map_ctx(hpb, srgn->mctx);
+		srgn->srgn_state = HPB_SRGN_UNUSED;
+		srgn->mctx = NULL;
+	}
+}
+
+static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
+				  struct ufshpb_region *rgn)
+{
+	struct victim_select_info *lru_info;
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	lru_info = &hpb->lru_info;
+
+	dev_dbg(&hpb->hpb_lu_dev, "evict region %d\n", rgn->rgn_idx);
+
+	ufshpb_cleanup_lru_info(lru_info, rgn);
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		ufshpb_purge_active_subregion(hpb, srgn);
+	}
+}
+
+static int ufshpb_evict_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	if (rgn->rgn_state == HPB_RGN_PINNED) {
+		dev_warn(&hpb->hpb_lu_dev,
+			 "pinned region cannot drop-out. region %d\n",
+			 rgn->rgn_idx);
+		goto out;
+	}
+	if (!list_empty(&rgn->list_lru_rgn)) {
+		if (ufshpb_check_issue_state_srgns(hpb, rgn)) {
+			ret = -EBUSY;
+			goto out;
+		}
+
+		__ufshpb_evict_region(hpb, rgn);
+	}
+out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return ret;
+}
+
+static inline struct
+ufshpb_rsp_field *ufshpb_get_hpb_rsp(struct ufshcd_lrb *lrbp)
+{
+	return (struct ufshpb_rsp_field *)&lrbp->ucd_rsp_ptr->sr.sense_data_len;
+}
+
+static int ufshpb_issue_map_req(struct ufshpb_lu *hpb,
+				struct ufshpb_region *rgn,
+				struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_req *map_req;
+	unsigned long flags;
+	int ret;
+	int err = -EAGAIN;
+	bool alloc_required = false;
+	enum HPB_RGN_STATE state = HPB_SRGN_INVALID;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	/*
+	 * Since the region state change occurs only in the map_work,
+	 * the state of the region cannot HPB_RGN_INACTIVE at this point.
+	 * The region state must be changed in the map_work
+	 */
+	WARN_ON(rgn->rgn_state == HPB_RGN_INACTIVE);
+
+	if (srgn->srgn_state == HPB_SRGN_UNUSED)
+		alloc_required = true;
+
+	/*
+	 * If the subregion is already ISSUED state,
+	 * a specific event (e.g., GC or wear-leveling, etc.) occurs in
+	 * the device and HPB response for map loading is received.
+	 * In this case, after finishing the HPB_READ_BUFFER,
+	 * the next HPB_READ_BUFFER is performed again to obtain the latest
+	 * map data.
+	 */
+	if (srgn->srgn_state == HPB_SRGN_ISSUED)
+		goto unlock_out;
+
+	srgn->srgn_state = HPB_SRGN_ISSUED;
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+
+	if (alloc_required) {
+		WARN_ON(srgn->mctx);
+		srgn->mctx = ufshpb_get_map_ctx(hpb);
+		if (!srgn->mctx) {
+			dev_notice(&hpb->hpb_lu_dev,
+			    "get map_ctx failed. region %d - %d\n",
+			    rgn->rgn_idx, srgn->srgn_idx);
+			state = HPB_SRGN_UNUSED;
+			goto change_srgn_state;
+		}
+	}
+
+	ufshpb_clear_dirty_bitmap(hpb, srgn);
+	map_req = ufshpb_get_map_req(hpb, srgn);
+	if (!map_req)
+		goto change_srgn_state;
+
+	ret = ufshpb_lu_get(hpb);
+	if (unlikely(ret)) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "%s: ufshpb_lu_get failed: %d", __func__, ret);
+		goto free_map_req;
+	}
+
+	ret = ufshpb_execute_map_req(hpb, map_req);
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "%s: issue map_req failed: %d, region %d - %d\n",
+			   __func__, ret, srgn->rgn_idx, srgn->srgn_idx);
+		ufshpb_lu_put(hpb);
+		goto free_map_req;
+	}
+	return 0;
+
+free_map_req:
+	ufshpb_put_map_req(hpb, map_req);
+change_srgn_state:
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	srgn->srgn_state = state;
+unlock_out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return err;
+}
+
+static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
+{
+	struct ufshpb_region *victim_rgn;
+	struct victim_select_info *lru_info = &hpb->lru_info;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	/*
+	 * If region belongs to lru_list, just move the region
+	 * to the front of lru list. because the state of the region
+	 * is already active-state
+	 */
+	if (!list_empty(&rgn->list_lru_rgn)) {
+		ufshpb_hit_lru_info(lru_info, rgn);
+		goto out;
+	}
+
+	if (rgn->rgn_state == HPB_RGN_INACTIVE) {
+		if (atomic_read(&lru_info->active_cnt)
+		    == lru_info->max_lru_active_cnt) {
+			/*
+			 * If the maximum number of active regions
+			 * is exceeded, evict the least recently used region.
+			 * This case may occur when the device responds
+			 * to the eviction information late.
+			 * It is okay to evict the least recently used region,
+			 * because the device could detect this region
+			 * by not issuing HPB_READ
+			 */
+			victim_rgn = ufshpb_victim_lru_info(hpb);
+			if (!victim_rgn) {
+				dev_warn(&hpb->hpb_lu_dev,
+				    "cannot get victim region error\n");
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			dev_dbg(&hpb->hpb_lu_dev,
+				"LRU full (%d), choost victim %d\n",
+				atomic_read(&lru_info->active_cnt),
+				victim_rgn->rgn_idx);
+			__ufshpb_evict_region(hpb, victim_rgn);
+		}
+
+		/*
+		 * When a region is added to lru_info list_head,
+		 * it is guaranteed that the subregion has been
+		 * assigned all mctx. If failed, try to receive mctx again
+		 * without being added to lru_info list_head
+		 */
+		ufshpb_add_lru_info(lru_info, rgn);
+	}
+out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return ret;
+}
+
+static void ufshpb_rsp_req_region_update(struct ufshpb_lu *hpb,
+					 struct ufshpb_rsp_field *rsp_field)
+{
+	int i, rgn_idx, srgn_idx;
+
+	/*
+	 * If the active region and the inactive region are the same,
+	 * we will inactivate this region.
+	 * The device could check this (region inactivated) and
+	 * will response the proper active region information
+	 */
+	spin_lock(&hpb->rsp_list_lock);
+	for (i = 0; i < rsp_field->active_rgn_cnt; i++) {
+		rgn_idx =
+			be16_to_cpu(rsp_field->hpb_active_field[i].active_rgn);
+		srgn_idx =
+			be16_to_cpu(rsp_field->hpb_active_field[i].active_srgn);
+
+		dev_dbg(&hpb->hpb_lu_dev, "activate(%d) region %d - %d\n",
+			i, rgn_idx, srgn_idx);
+		ufshpb_update_active_info(hpb, rgn_idx, srgn_idx);
+		atomic_inc(&hpb->stats.rb_active_cnt);
+	}
+
+	for (i = 0; i < rsp_field->inactive_rgn_cnt; i++) {
+		rgn_idx = be16_to_cpu(rsp_field->hpb_inactive_field[i]);
+		dev_dbg(&hpb->hpb_lu_dev, "inactivate(%d) region %d\n",
+			i, rgn_idx);
+		ufshpb_update_inactive_info(hpb, rgn_idx);
+		atomic_inc(&hpb->stats.rb_inactive_cnt);
+	}
+	spin_unlock(&hpb->rsp_list_lock);
+
+	dev_dbg(&hpb->hpb_lu_dev, "Noti: #ACT %u #INACT %u\n",
+		rsp_field->active_rgn_cnt, rsp_field->inactive_rgn_cnt);
+
+	queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+}
+
+/* routine : isr (ufs) */
+static void ufshpb_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufshpb_lu *hpb;
+	struct ufshpb_rsp_field *rsp_field;
+	int data_seg_len, ret;
+
+	data_seg_len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2)
+		& MASK_RSP_UPIU_DATA_SEG_LEN;
+
+	/* To flush remained rsp_list, we queue the map_work task */
+	if (!data_seg_len) {
+		if (!ufshpb_is_general_lun(lrbp->lun))
+			return;
+
+		hpb = ufshpb_get_hpb_data(lrbp->cmd);
+		ret = ufshpb_lu_get(hpb);
+		if (ret)
+			return;
+
+		if (!ufshpb_is_empty_rsp_lists(hpb))
+			queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+
+		goto put_hpb;
+	}
+
+	/* Check HPB_UPDATE_ALERT */
+	if (!(lrbp->ucd_rsp_ptr->header.dword_2 &
+	      UPIU_HEADER_DWORD(0, 2, 0, 0)))
+		return;
+
+	rsp_field = ufshpb_get_hpb_rsp(lrbp);
+	if (ufshpb_may_field_valid(hba, lrbp, rsp_field))
+		return;
+
+	hpb = ufshpb_get_hpb_data(lrbp->cmd);
+	ret = ufshpb_lu_get(hpb);
+	if (ret)
+		return;
+
+	atomic_inc(&hpb->stats.rb_noti_cnt);
+
+	switch (rsp_field->hpb_type) {
+	case HPB_RSP_REQ_REGION_UPDATE:
+		WARN_ON(data_seg_len != DEV_DATA_SEG_LEN);
+		ufshpb_rsp_req_region_update(hpb, rsp_field);
+		break;
+	case HPB_RSP_DEV_RESET:
+		dev_warn(&hpb->hpb_lu_dev,
+			 "UFS device lost HPB information during PM.\n");
+		break;
+	default:
+		dev_notice(&hpb->hpb_lu_dev, "hpb_type is not available: %d\n",
+			   rsp_field->hpb_type);
+		break;
+	}
+put_hpb:
+	ufshpb_lu_put(hpb);
+}
+
+static void ufshpb_add_active_list(struct ufshpb_lu *hpb,
+				   struct ufshpb_region *rgn,
+				   struct ufshpb_subregion *srgn)
+{
+	if (!list_empty(&rgn->list_inact_rgn))
+		return;
+
+	if (!list_empty(&srgn->list_act_srgn)) {
+		list_move(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+		return;
+	}
+
+	list_add(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+}
+
+static void ufshpb_add_pending_evict_list(struct ufshpb_lu *hpb,
+				    struct ufshpb_region *rgn,
+				    struct list_head *pending_list)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	if (!list_empty(&rgn->list_inact_rgn))
+		return;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		if (!list_empty(&srgn->list_act_srgn))
+			return;
+	}
+
+	list_add_tail(&rgn->list_inact_rgn, pending_list);
+}
+
+static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	struct ufshpb_map_ctx *mctx;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
+						struct ufshpb_subregion,
+						list_act_srgn))) {
+		list_del_init(&srgn->list_act_srgn);
+		spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+		rgn = hpb->rgn_tbl + srgn->rgn_idx;
+		mctx = NULL;
+		ret = ufshpb_add_region(hpb, rgn);
+		if (ret)
+			break;
+
+		ret = ufshpb_issue_map_req(hpb, rgn, srgn);
+		if (ret) {
+			dev_notice(&hpb->hpb_lu_dev,
+			    "issue map_req failed. ret %d, region %d - %d\n",
+			    ret, rgn->rgn_idx, srgn->srgn_idx);
+			break;
+		}
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	}
+
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
+			   rgn->rgn_idx, srgn->srgn_idx);
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+		ufshpb_add_active_list(hpb, rgn, srgn);
+	}
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static void ufshpb_run_inactive_region_list(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn;
+	unsigned long flags;
+	int ret;
+	LIST_HEAD(pending_list);
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	while ((rgn = list_first_entry_or_null(&hpb->lh_inact_rgn,
+					       struct ufshpb_region,
+					       list_inact_rgn))) {
+		list_del_init(&rgn->list_inact_rgn);
+		spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+		ret = ufshpb_evict_region(hpb, rgn);
+		if (ret) {
+			spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+			ufshpb_add_pending_evict_list(hpb, rgn, &pending_list);
+			spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+		}
+
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	}
+
+	list_splice(&pending_list, &hpb->lh_inact_rgn);
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static void ufshpb_map_work_handler(struct work_struct *work)
+{
+	struct ufshpb_lu *hpb;
+	int ret;
+
+	hpb = container_of(work, struct ufshpb_lu, map_work);
+	ret = ufshpb_lu_get(hpb);
+	if (ret) {
+		dev_info(&hpb->hpb_lu_dev, "%s: exit, state %d\n",
+			 __func__, ufshpb_get_state(hpb));
+		return;
+	}
+
+	ufshpb_run_inactive_region_list(hpb);
+	ufshpb_run_active_subregion_list(hpb);
+
+	ufshpb_lu_put(hpb);
+}
+
+/*
+ * this function doesn't need to hold lock due to be called in init.
+ * (hpb_state_lock, rsp_list_lock, etc..)
+ */
+static int ufshpb_init_pinned_active_region(struct ufs_hba *hba,
+					    struct ufshpb_lu *hpb,
+					    struct ufshpb_region *rgn)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx, i;
+	int err = 0;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		srgn->mctx = ufshpb_get_map_ctx(hpb);
+		srgn->srgn_state = HPB_SRGN_INVALID;
+		if (!srgn->mctx) {
+			dev_err(hba->dev,
+				"alloc mctx for pinned region failed\n");
+			goto release;
+		}
+
+		list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+	}
+
+	rgn->rgn_state = HPB_RGN_PINNED;
+	return 0;
+
+release:
+	for (i = 0; i < srgn_idx; i++) {
+		srgn = rgn->srgn_tbl + i;
+		ufshpb_put_map_ctx(hpb, srgn->mctx);
+	}
+	return err;
+}
+
 static void ufshpb_init_subregion_tbl(struct ufshpb_lu *hpb,
 				      struct ufshpb_region *rgn)
 {
@@ -101,6 +919,8 @@  static void ufshpb_init_lu_parameter(struct ufs_hba *hba,
 	hpb->lu_pinned_end = hpb_lu_info->num_pinned ?
 		(hpb_lu_info->pinned_start + hpb_lu_info->num_pinned - 1)
 		: PINNED_NOT_SET;
+	hpb->lru_info.max_lru_active_cnt =
+		hpb_lu_info->max_active_rgns - hpb_lu_info->num_pinned;
 
 	rgn_mem_size = (1ULL << hpb_dev_info->rgn_size) * HPB_RGN_SIZE_UNIT
 		/ HPB_ENTRY_BLOCK_SIZE * HPB_ENTRY_SIZE;
@@ -154,6 +974,9 @@  static int ufshpb_alloc_region_tbl(struct ufs_hba *hba, struct ufshpb_lu *hpb)
 		rgn = rgn_table + rgn_idx;
 		rgn->rgn_idx = rgn_idx;
 
+		INIT_LIST_HEAD(&rgn->list_inact_rgn);
+		INIT_LIST_HEAD(&rgn->list_lru_rgn);
+
 		if (rgn_idx == hpb->rgns_per_lu - 1)
 			srgn_cnt = ((hpb->srgns_per_lu - 1) %
 				    hpb->srgns_per_rgn) + 1;
@@ -163,7 +986,13 @@  static int ufshpb_alloc_region_tbl(struct ufs_hba *hba, struct ufshpb_lu *hpb)
 			goto release_srgn_table;
 		ufshpb_init_subregion_tbl(hpb, rgn);
 
-		rgn->rgn_state = HPB_RGN_INACTIVE;
+		if (ufshpb_is_pinned_region(hpb, rgn_idx)) {
+			ret = ufshpb_init_pinned_active_region(hba, hpb, rgn);
+			if (ret)
+				goto release_srgn_table;
+		} else {
+			rgn->rgn_state = HPB_RGN_INACTIVE;
+		}
 	}
 
 	return 0;
@@ -187,7 +1016,10 @@  static void ufshpb_destroy_subregion_tbl(struct ufshpb_lu *hpb,
 		struct ufshpb_subregion *srgn;
 
 		srgn = rgn->srgn_tbl + srgn_idx;
-		srgn->srgn_state = HPB_SRGN_UNUSED;
+		if (srgn->srgn_state != HPB_SRGN_UNUSED) {
+			srgn->srgn_state = HPB_SRGN_UNUSED;
+			ufshpb_put_map_ctx(hpb, srgn->mctx);
+		}
 	}
 }
 
@@ -217,6 +1049,33 @@  static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
 	int ret;
 
 	spin_lock_init(&hpb->hpb_state_lock);
+	spin_lock_init(&hpb->rsp_list_lock);
+
+	INIT_LIST_HEAD(&hpb->lru_info.lh_lru_rgn);
+	INIT_LIST_HEAD(&hpb->lh_act_srgn);
+	INIT_LIST_HEAD(&hpb->lh_inact_rgn);
+	INIT_LIST_HEAD(&hpb->list_hpb_lu);
+
+	INIT_WORK(&hpb->map_work, ufshpb_map_work_handler);
+
+	hpb->map_req_cache = kmem_cache_create("ufshpb_req_cache",
+			  sizeof(struct ufshpb_req), 0, 0, NULL);
+	if (!hpb->map_req_cache) {
+		dev_err(hba->dev, "ufshpb(%d) ufshpb_req_cache create fail",
+			hpb->lun);
+		return -ENOMEM;
+	}
+
+	hpb->m_page_cache = kmem_cache_create("ufshpb_m_page_cache",
+			  sizeof(struct page *) * hpb->pages_per_srgn,
+			  0, 0, NULL);
+	if (!hpb->m_page_cache) {
+		dev_err(hba->dev, "ufshpb(%d) ufshpb_m_page_cache create fail",
+			hpb->lun);
+		ret = -ENOMEM;
+		goto release_req_cache;
+	}
+
 
 	ret = ufshpb_alloc_region_tbl(hba, hpb);
 	if (ret)
@@ -230,6 +1089,10 @@  static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
 
 release_rgn_table:
 	ufshpb_destroy_region_tbl(hpb);
+release_m_page_cache:
+	kmem_cache_destroy(hpb->m_page_cache);
+release_req_cache:
+	kmem_cache_destroy(hpb->map_req_cache);
 	return ret;
 }
 
@@ -261,10 +1124,42 @@  static struct ufshpb_lu *ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
 	return NULL;
 }
 
+static void ufshpb_discard_rsp_lists(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn, *next_rgn;
+	struct ufshpb_subregion *srgn, *next_srgn;
+	unsigned long flags;
+
+	/*
+	 * If the device reset occurred, the remained HPB region information
+	 * may be stale. Therefore, by dicarding the lists of HPB response
+	 * that remained after reset, it prevents unnecessary work.
+	 */
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	list_for_each_entry_safe(rgn, next_rgn, &hpb->lh_inact_rgn,
+				 list_inact_rgn)
+		list_del_init(&rgn->list_inact_rgn);
+
+	list_for_each_entry_safe(srgn, next_srgn, &hpb->lh_act_srgn,
+				 list_act_srgn)
+		list_del_init(&srgn->list_act_srgn);
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static inline void ufshpb_cancel_jobs(struct ufshpb_lu *hpb)
+{
+	cancel_work_sync(&hpb->map_work);
+}
+
 static void ufshpb_lu_release(struct ufshpb_lu *hpb)
 {
+	ufshpb_cancel_jobs(hpb);
+
 	ufshpb_destroy_region_tbl(hpb);
 
+	kmem_cache_destroy(hpb->map_req_cache);
+	kmem_cache_destroy(hpb->m_page_cache);
+
 	list_del_init(&hpb->list_hpb_lu);
 }
 
@@ -351,6 +1246,9 @@  static void ufshpb_reset_host(struct ufs_hba *hba)
 		dev_info(&hpb->hpb_lu_dev, "ufshpb run reset_host");
 
 		ufshpb_set_state(hpb, HPB_RESET);
+		ufshpb_cancel_jobs(hpb);
+		ufshpb_discard_rsp_lists(hpb);
+
 		ufshpb_lu_put(hpb);
 	}
 }
@@ -365,6 +1263,7 @@  static void ufshpb_suspend(struct ufs_hba *hba)
 
 		dev_info(&hpb->hpb_lu_dev, "ufshpb goto suspend");
 		ufshpb_set_state(hpb, HPB_SUSPEND);
+		ufshpb_cancel_jobs(hpb);
 
 		ufshpb_lu_put(hpb);
 	}
@@ -380,6 +1279,9 @@  static void ufshpb_resume(struct ufs_hba *hba)
 
 		dev_info(&hpb->hpb_lu_dev, "ufshpb resume");
 		ufshpb_set_state(hpb, HPB_PRESENT);
+		if (!ufshpb_is_empty_rsp_lists(hpb))
+			queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+
 		ufshpb_lu_put(hpb);
 	}
 }
@@ -661,6 +1563,14 @@  static void ufshpb_scan_hpb_lu(struct ufs_hba *hba,
 		list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
 			dev_info(&hpb->hpb_lu_dev, "set state to present\n");
 			ufshpb_set_state(hpb, HPB_PRESENT);
+
+			if ((hpb->lu_pinned_end - hpb->lu_pinned_start) > 0) {
+				dev_info(&hpb->hpb_lu_dev,
+				    "loading pinned regions %d - %d\n",
+				    hpb->lu_pinned_start, hpb->lu_pinned_end);
+				queue_work(ufshpb_drv.ufshpb_wq,
+					&hpb->map_work);
+			}
 		}
 	}
 }
@@ -728,6 +1638,8 @@  static int ufshpb_remove(struct device *dev)
 		sdev = hpb->sdev_ufs_lu;
 		sdev->hostdata = NULL;
 
+		ufshpb_cancel_jobs(hpb);
+
 		device_del(&hpb->hpb_lu_dev);
 
 		dev_info(&hpb->hpb_lu_dev, "hpb_lu_dev refcnt %d\n",
@@ -768,16 +1680,69 @@  static int __init ufshpb_init(void)
 	unsigned int pool_size;
 	int ret;
 
+
+	ufshpb_drv.ufshpb_mctx_cache = kmem_cache_create("ufshpb_mctx_cache",
+					sizeof(struct ufshpb_map_ctx),
+					0, 0, NULL);
+	if (!ufshpb_drv.ufshpb_mctx_cache) {
+		pr_err("ufshpb: cannot init mctx cache\n");
+		return -ENOMEM;
+	}
+
+	pool_size = DIV_ROUND_UP(ufshpb_host_map_kbytes * 1024, 4096);
+	pr_info("%s:%d ufshpb_host_map_kbytes %u pool_size %u\n",
+	       __func__, __LINE__, ufshpb_host_map_kbytes, pool_size);
+
+	ufshpb_drv.ufshpb_mctx_pool = mempool_create_slab_pool(
+				     pool_size, ufshpb_drv.ufshpb_mctx_cache);
+	if (!ufshpb_drv.ufshpb_mctx_pool) {
+		pr_err("ufshpb: cannot init mctx pool\n");
+		ret = -ENOMEM;
+		goto release_mctx_cache;
+	}
+
+	ufshpb_drv.ufshpb_page_pool = mempool_create_page_pool(pool_size, 0);
+	if (!ufshpb_drv.ufshpb_page_pool) {
+		pr_err("ufshpb: cannot init page pool\n");
+		ret = -ENOMEM;
+		goto release_mctx_pool;
+	}
+
+	ufshpb_drv.ufshpb_wq = alloc_workqueue("ufshpb-wq",
+					WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
+	if (!ufshpb_drv.ufshpb_wq) {
+		pr_err("ufshpb: alloc workqueue failed\n");
+		ret = -ENOMEM;
+		goto release_page_pool;
+	}
+
 	ret = driver_register(&ufshpb_drv.drv);
-	if (ret)
+	if (ret) {
 		pr_err("ufshpb: driver register failed\n");
+		goto release_wq;
+	}
 
+	return 0;
+release_wq:
+	destroy_workqueue(ufshpb_drv.ufshpb_wq);
+release_page_pool:
+	mempool_destroy(ufshpb_drv.ufshpb_page_pool);
+release_mctx_pool:
+	mempool_destroy(ufshpb_drv.ufshpb_mctx_pool);
+release_mctx_cache:
+	kmem_cache_destroy(ufshpb_drv.ufshpb_mctx_cache);
 	return ret;
 }
 
 static void __exit ufshpb_exit(void)
 {
 	driver_unregister(&ufshpb_drv.drv);
+
+	mempool_destroy(ufshpb_drv.ufshpb_page_pool);
+	mempool_destroy(ufshpb_drv.ufshpb_mctx_pool);
+	kmem_cache_destroy(ufshpb_drv.ufshpb_mctx_cache);
+
+	destroy_workqueue(ufshpb_drv.ufshpb_wq);
 }
 
 MODULE_AUTHOR("Yongmyong Lee <ymhungry.lee@samsung.com>");
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index eaa4a3e035b1..d9c27348d354 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -101,10 +101,36 @@  struct ufshpb_lu_info {
 	int max_active_rgns;
 };
 
+struct ufshpb_active_field {
+	__be16 active_rgn;
+	__be16 active_srgn;
+} __packed;
+
+struct ufshpb_rsp_field {
+	__be16 sense_data_len;
+	u8 desc_type;
+	u8 additional_len;
+	u8 hpb_type;
+	u8 reserved;
+	u8 active_rgn_cnt;
+	u8 inactive_rgn_cnt;
+	struct ufshpb_active_field hpb_active_field[2];
+	__be16 hpb_inactive_field[2];
+} __packed;
+
+struct ufshpb_map_ctx {
+	struct page **m_page;
+	unsigned long *ppn_dirty;
+};
+
 struct ufshpb_subregion {
+	struct ufshpb_map_ctx *mctx;
 	enum HPB_SRGN_STATE srgn_state;
 	int rgn_idx;
 	int srgn_idx;
+
+	/* below information is used by rsp_list */
+	struct list_head list_act_srgn;
 };
 
 struct ufshpb_region {
@@ -112,6 +138,39 @@  struct ufshpb_region {
 	enum HPB_RGN_STATE rgn_state;
 	int rgn_idx;
 	int srgn_cnt;
+
+	/* below information is used by rsp_list */
+	struct list_head list_inact_rgn;
+
+	/* below information is used by lru */
+	struct list_head list_lru_rgn;
+};
+
+/**
+ * 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
+ * @mctx: L2P map information
+ * @rgn_idx: target region index
+ * @srgn_idx: target sub-region index
+ * @lun: target logical unit number
+ */
+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;
+	unsigned int lun;
+};
+
+struct victim_select_info {
+	struct list_head lh_lru_rgn;
+	int max_lru_active_cnt; /* supported hpb #region - pinned #region */
+	atomic_t active_cnt;
 };
 
 struct ufshpb_stats {
@@ -134,6 +193,16 @@  struct ufshpb_lu {
 	spinlock_t hpb_state_lock;
 	atomic_t hpb_state; /* hpb_state_lock */
 
+	spinlock_t rsp_list_lock;
+	struct list_head lh_act_srgn; /* rsp_list_lock */
+	struct list_head lh_inact_rgn; /* rsp_list_lock */
+
+	/* cached L2P map management worker */
+	struct work_struct map_work;
+
+	/* for selecting victim */
+	struct victim_select_info lru_info;
+
 	/* pinned region information */
 	u32 lu_pinned_start;
 	u32 lu_pinned_end;
@@ -152,6 +221,9 @@  struct ufshpb_lu {
 
 	struct ufshpb_stats stats;
 
+	struct kmem_cache *map_req_cache;
+	struct kmem_cache *m_page_cache;
+
 	struct ufsf_feature_info *ufsf;
 	struct list_head list_hpb_lu;
 };